Smart Community

ISSN 0429-8284 Whole Number 235

Smart Community

CONTENTS

Smart Community [Preface] Towards to a smart community: the role of smart grids 110

Present Status and Future Outlook for Smart Communities 111

Fuji Electric’s Efforts Involving Next-generation Energy and 116 Social Systems

Microgrid System for Isolated Islands 124 Cover photo:

To expand the adoption of renewable energy, smart grids, which are used to cre- Cooperative University-Industry Research with Zhejiang University: 130 ate intelligent power networks, are being Toward the Creation of Smart Grid Related Business deployed in smart communities that aim to reduce their environmental impact through the efﬁ cient use of electrical and thermal energy. System Technology that Supports Next Generation Electricity Delivery 134 Fuji Electric supplies energy-creating technologies, such as photovoltaic generation and wind power generation and fuel Power Electronics Technology that Supports Smart Grid 139 cells, energy saving technologies, power stabilization technologies, energy management systems and a variety of other technologies including products for electric Integrated Energy Management System Platform 146 vehicles. The cover photo shows a representation of the necessity for energy-creating Supplemental Explanation technologies, such as photovoltaic generation and fuel cells, and energy management Isolated operation detection method 152 systems for using energy efﬁ ciently, in smart communities.

FUJI ELECTRIC REVIEW vol.57 no.4 2011 date of issue: November 20, 2011

editor-in-chief and publisher Naoya Eguchi Fuji Electric Co., Ltd. reserves all rights concerning the Corporate R & D Headquarters republication and publication after translation into other Fuji Electric Co., Ltd. languages of articles appearing herein. Gate City Ohsaki, East Tower, All brand names and product names in this journal might be 11-2, Osaki 1-chome, Shinagawa-ku, trademarks or registered trademarks of their respective companies. Tokyo 141-0032, Japan http://www.fujielectric.co.jp

editorial offi ce Fuji Electric Journal Editorial Offi ce c/o Fuji Offi ce & Life Service Co., Ltd. 9-4, Asahigaoka 1-chome, Hino-shi, Tokyo 191-0065, Japan Preface

Towards to a smart community: the role of smart grids

Deqiang Gan † Rongxiang Zhao ‡ Deqiang Gan Rongxiang Zhao

In a smart community, customers will be able to teractions between the network and the demand. In interact, in various ways, with power suppliers in such the same time SGCC published a staged implementa- a way that the social welfare of customers and suppli- tion plan of SGCC smart grid. In 2010, the Chinese ers are maximized. The idea of smart grid, originated government followed an ambitious research plan of in the USA early 2000, further developed in Europe, smart grid, focusing on the interconnection of renew- now widely accepted across the world including China, able energy and electric vehicles. In addition, two can help accomplish this goal. The emergence of smart demonstration projects are under construction. The grids is often motivated by the need of reducing emis- fi rst one, Jinghai City Smart Grid Project, was initiat- sions, maintaining energy security, preventing large- ed in the fall of 2009. Upon completion, 24.62% of elec- scale blackout, and providing reliability-differentiated tricity consumptions of this mid-size town in Tianjin powers. (with a population of about 350,000), will be supplied The fundamental principles of modern electric by green power. This grid will also be integrated with power grid were invented about half a century ago. cable television, IP telephone, realizing remote control, Under the classic notion of regulatory economics, remote measuring, and remote information collection. power industry had been considered as a natural mo- Several advanced technologies, including energy stor- nopoly, where power suppliers are obliged to supply, age systems, on-line equipment monitoring, smart at regulated prices, electrical power to demands which building, electrical vehicles, etc., will be tested and are generally inelastic. This “golden rule” was altered exhibited. Jinghai Smart Grid is also expected to real- with the introduction of electric power market some 20 ize self-healing power supply to local customers. The years ago in many countries. However, this market is second demonstration project is located in Yangzhou, a not a truly ideal market, not without the introduction city nearby Shanghai. of demand participation. A smart grid does just that. In Zhejiang University, we have been working very Enabled by the state-of-the-art communication/ hard, with the fi nancial support of several entities in- control technology, a smart grid allows power sup- cluding Fuji Electric, on a number of challenging tasks. pliers to collect the real-time information of elec- Our goal is to develop practical solutions to microgrid, tric power customers such that differentiated elec- virtual power plant, and grid-friendly load. Take the tric powers are delivered. A smart grid better research on grid-friendly load as an example. An in- facilitates the penetration of green power, which is teresting observation we found is that: much of the often diffi cult to accommodate in existing grid. A electrical loads can be temporarily reduced without in- smart grid may also allow customers to sell a va- troducing an essential impact on load performance. A riety of electric power services, such as but not classical example is that of residential air conditioning limited to, downward reserves (turn on a washer load. This implies that the characteristics of loads can midnight you may end up with earning credit!), be made grid-friendly. What is missing here is the in- frequency regulation, etc., to the grid. In a nutshell, a formation exchange between the network and the load. smart grid serves as the next-generation infrastructure Therefore, in a smart grid regime, the notion of load which permits customers to enjoy in an ideal market. participation should include frequency control, emer- The notion of smart grid is rapidly gaining public- gency voltage stability control, etc. This seems to be a ity in China. In May 2009, State Grid Corporation potentially powerful and relatively new concept com- of China (SGCC) described a vision of smart grid as: pared with the traditional demand response programs. A strong power grid that takes advantage of modern In summary, despite of the confusions and contro- information technology, that fully supports a digital versies, smart grids are gaining acceptance world wide. economy, that enjoys automation, and that allows in- It is our view that eventually the core functions of smart grids will be identifi ed and implemented, lead- † Professor, School of Electrical Engineering ing to the development of a much more effi cient infra- Zhejiang University structure, a win-win solution to both power suppliers ‡ Professor, Zhejiang University and customers.

110 Present Status and Future Outlook for Smart Communities Kenzo Sugai † Naoto Kobayashi † Jimpei Kuwayama †

ABSTRACT

The development of smart communities that provide low-carbon, highly convenient urban infrastructures are a global trend enabled by the adoption of smart power grids, efﬁ cient energy use, a stable supply of water and the like. Fuji Electric, which specializes in the core technology of power electronics, is working to broaden the range of avail- able smart community products related to public infrastructure. These products have a uniform interface, and are all controlled by an integrated energy management system (EMS) that allows for the simultaneous realization of energy visualization and optimal operation of equipment. The promotion of overseas exports is also under consideration as a way to expand the smart community business further. feature issue: Smart Community

1. Introduction stored rapidly by using diversifi ed local energy sources. Furthermore, by incorporating the smart grid con- In recent years, with the rapid industrialization cept, expanding the utilization of various types of en- and population growth in the emerging nations of ergy, and through utilizing buildings having a highly China, India and elsewhere, demand has increased for effi cient energy savings function, highly effi cient trans- primary energy, including crude oil and natural gas, portation systems and stable and safe water supply and the resulting higher prices and supply instability systems, urban development and urban regeneration have led to problems. On the other hand, in the devel- projects are being planned and being carried out as oped nations of Japan, Europe and North America, in “smart communities” for realizing a low-carbon and addition to the popularization of electric vehicles and highly convenient urban infrastructure. the expanded usage of solar power and wind power, In projects related to such smart communities, IT “smart grid” technology that combines electric power companies are active participants. Moreover, because grids with information technology to dramatically in- smart communities involve national energy policy and crease the power supply capability and usage effi ciency growth strategy, the advancement of smart communi- is becoming a strategic technology for enhancing inter- ties has expanded into a global movement. national competitiveness. In Japan, since 1980, in initiatives led by the na- With the widespread usage and interconnection tional government or electric utility companies, various to power grids of distributed power sources and elec- technical measures have been developed for improving tric power storage systems among end-users, the fl ow power supply reliability and expanding usage of renew- of power, rather than being unidirectional from the able energy, and various efforts have been advanced power plants of electric power companies to end-users, for improving the sophistication of power grids. Fur- is becoming a bidirectional fl ow or is fl owing back and thermore, in response to recent global trends, various forth among end-users. A smart grid is a power grid national projects are being advanced, including nation- provided with a function for performing optimal sup- al smart community demonstration projects targeting ply/demand control of electric power. energy infrastructure exports to foreign countries, and Moreover, with a smart grid, since the grid is investigations of urban infrastructure construction in distributed at the regional level and is able to accom- emerging countries. modate distributed power sources providing large Through previous efforts, primarily through col- amounts of regional power resources such as solar, laborative development with domestic Japanese power wind and biomass power, the regional energy inde- companies to develop automation systems for distribu- pendence can be enhanced signifi cantly. Thus, the tion systems and remote meter reading systems for benefi ts of a smart grid are that in the event of an power meters, Fuji Electric has accumulated products, earthquake or other regional disaster, the risk of dam- technology and know-how relating to the advanced age to the energy infrastructure is distributed, and the operation of power grids. Moreover, Fuji Electric par- supply of energy to important regional sites can be re- ticipated in the “Demonstrative Project of a Regional Power Grid with Various New Energies” conducted † Fuji Electric Co., Ltd. by the New Energy and Industrial Technology Devel-

111 opment Organization (NEDO) for a period of 5 years exceeds about 10% of the power grid supply capacity, beginning in 2003, and has amassed a proven track the frequency and voltage of the power grid will be- record for developing and evaluating “microgrid control come unstable and power quality problems will arise. technology” that balances the supply and demand of Additionally, depending on the load pattern of the energy within a regional grid consisting primarily of power grid, it can be expected that surplus power will renewable energy sources such as solar power, wind be generated and adversely affect the protection and power and biomass power. control functions of the power grid in some cases. Combining its accumulated advanced power grid In terms of the capacity utilization ratio of the sys- technology with end-user power savings technology tem, the addition of large-scale equipment to the power and public system technologies such as transporta- grid-side is not always an effective way to compensate tion and water environment technologies, Fuji Electric for the ﬂ uctuations in solar and wind power genera- is currently participating in national demonstration tion, however. For this reason, the end-user and the projects and research projects relating to smart com- power grid must be organically linked by means of munities, and by integrating its in-house resources for information technology, and the control of the user various ﬁ elds, Fuji Electric is helping to advance the equipment (user’s grid) and of the large-scale power development and expand the lineup of smart commu- grid must be coordinated. A smart grid can realize nity products and technologies. such coordinated control, and is said to be a means for This special issue reports on Fuji Electric’s sup- solving problems when adopting large amounts of solar port of these demonstration projects, product develop- and wind power. ment for more advanced power grids and more highly Figure 1 shows the correlation between Fuji Elec- sophisticated energy utilization by end-users in order tric’s assumption of the increase in solar and wind to realize smart communities, and efforts to establish power generation and capital investment trends( 1) . For elemental technologies. the planned global spread of solar and wind power, the This paper describes the smart communities envi- need for “user grids” will increase beginning in 2012, sioned by Fuji Electric and their associated challenges, and smart grids are expected to come into widespread as well as the systems for technologies and products in use as of 2017. Additionally, together with the associ- Fuji Electric’s smart communities. For further details, ated capital investment, smart communities having please refer to the individual papers that follow this high-level urban features are also expected to increase. one. 2.2 From smart grids to smart communities 2. Trends Toward Smart Communities The populations of Asia and Africa are to increase dramatically in the future. In these regions, industri- 2.1 Smart grids and the mass adoption of solar power alization is progressing rapidly, especially in nations generation and wind power generation with emerging economies such as India and China, and With the aim of realizing a low carbon society, the large investments are being made for the development increased adoption of solar power and wind power is of industrial parks and urban development, as well as being promoted worldwide. the accompanying construction of public infrastructure These unstable sources of energy, with the excep- tion of small power supply applications such as in remote areas, are directly connected to power grids. In Extraordinary investment in China, India and Middle East general, if the mass adoption of solar and wind power Energy demand*1 (increasing)

New urban India type 595 Mt 1,000

(strong) China

2 2.0 Smart grid prevalence Middle East 1,970 ™Extraordinary investment 546 Mt Adoption of new energy 13% ™Optimization of tradeoff Mt 800 between energy and resources Ratio 11% exceeds 10% Solar power/ ★ wind power ratio Adoption of solar 600 power and wind 9% power generation Europe USA 1.0 Japan 1,826 Mt 2,337 Mt 514 Mt (flat) 400 Expansion of Expansion of grid Renewed Existing infrastructure (weak)

★ Existing infrastructure* customer grids business urban type Energy demand (decreasing, flat) Expansion of environment 200 and resource regeneration Equipment investment trends 25% CO2 reduction *1 Energy demand: Million tons of oil equivalent (shown by area size, 2007) target Growth rate (Vertical axis, 2030/2007 ratio) 3% (Source: WORLD ENERGY OUTLOOK 2009) *2 Strength of existing infrastructure: Energy and environment business strategy Global renewable energy generation capacity (GW) 20062009 2015 2020 2025 2030 (Source: Mitsubishi Research Institute, (Year) Sep. 2009)

Fig.1 Smart grid equipment investment trends Fig.2 Energy infrastructure portfolio

112 Vol. 57 No. 4 FUJI ELECTRIC REVIEW Building EMS* Supply side (energy creation)

Factory EMS Thermal power plant Solar power plant Home EMS Large-scale energy grid Geothermal power plant Fuel cell (hydro, thermal and nuclear power) Smart grid, utility grid

Electric power, Solar power generation Distribution hydrogen, heat, water Power system and distribution control system Power storage Energy optimal control system Balancing control system Community energy Wind power management system generation Utility management Demand side (energy savings) Traffic control Environmental monitoring Power semiconductor Measuring device Traffic control and Inverter Power supply environmental monitoring Motor Power control system

Traffic and distribution

Fig.4 Fuji Electric’s business areas Environment and topography feature issue: Smart Community

* EMS: Energy Management System 3. Fuji Electric’s Activities for Smart Fig.3 Overview of smart communities Communities

3.1 Fuji Electric’s business areas The main markets for smart communities are new urban development in emerging nations and urban re- for supplying energy and water, and for transporta- newal in industrialized nations. Rather than provide tion, distribution and the like. individual elemental technologies, what is needed is a In Japan, Europe, the United States and other one-stop business scheme capable of constructing and developed nations, energy demand is fl at and in some operating a continuous energy supply chain, from an cases may decrease in the long-term due to a declining energy infrastructure consisting of energy supply and population and an overseas shift of production bases. energy distribution functions to the effective utilization In these countries, infrastructure investment is expect- of energy on the user side (user’s grid). Additionally, ed for renewal of the energy infrastructure developed functions for water supply, waste disposal, transporta- during times of economic growth and to successively tion, distribution and the like are also requested of the update that infrastructure into smart grids. developers of comprehensive social systems. Figure 2 shows a portfolio of “new urban” and “ur- Figure 4 shows the business areas in which Fuji ban renewal” type infrastructure. Electric is involved with smart community projects. Currently, more than 300 urban development Based upon high-performance power semiconductor and urban renewal projects are underway throughout technology, and with power electronics capable of the world. Not limited to providing power grids with “freely controlling energy” positioned as a core technol- smart functionality, these concepts have been expand- ogy, Fuji Electric has established a product lineup that ed to the creation of eco-friendly urban spaces that ranges from products for supplying energy to a smart combine water supply, transportation, distribution and community to products for the user’s grid. These energy infrastructure, i.e. smart communities (Eco- products aim to achieve integrated operation through cities). (See Fig. 3.) the use of an integrated energy management system Smart communities can be defi ned in various ways (EMS) platform, which is a mechanism that coordi- according to various issues such as a particular coun- nates shared information. try’s energy policy, energy security and so on. The Eco-city projects in the Middle East will be 3.2 Energy supply-side products powered entirely by renewable energy, and aim to Fuji Electric possesses plant technology relating create the world’s fi rst carbon neutral and zero waste to large-scale thermal power, hydropower, and geo- eco-friendly cities. Moreover, China is moving forward thermal (fl ash) power generation. Fuji Electric also with 13 national eco-city projects, and has posted per- supplies distinctive energy supply-side products such formance indicators for 32 items including a renewable as binary generators that are able to utilize low tem- energy usage of greater than 30%, a daily waste detox- perature geothermal energy, lightweight and fl exible ifi cation rate of greater than 70%, and a sewage water amorphous solar cells, industrial-use phosphoric acid recycling rate of greater than 30%. fuel cells and so on. Additionally, Fuji Electric also has a lineup of products for power substation and protec-

Present Status and Future Outlook for Smart Communities 113 tion systems for safely connecting the above supply- (2) User’s grids side products to a power grid, power stabilizers that The key role of a smart community is considered to smooth solar and wind power fl uctuations and supply be the achievement of energy savings in the household, stabilized power to power grids, and so on. industry and transportation fi elds and the like. Targeting the end-users of plants and buildings, 3.3 Distribution and demand-side products Fuji Electric installs and deploys EMSs for energy vi- Figure 5 shows Fuji Electric’s envisioned structure sualization, analysis and evaluation, and the overall of a smart community. optimized operation of equipment. Fuji Electric also At Fuji Electric, “smart communities” are posi- applies power electronics to develop “green navigation” tioned as a type of public infrastructure that encom- and provide a total solution for energy savings. passes smart grids, transportation systems, water In addition, for Internet data centers (IDC) where and sewage management, and the like. The smart the energy demand density has increased as servers grid structure is divided into fi ve layers, with the core have become more highly integrated, green IDC solu- components of “power devices” forming the fi rst layer, tions centering on ultra-effi cient uninterruptible power followed by “power electronics equipment” and “user’s supplies and local air conditioning systems are being grids” for performing power conversion and power con- proposed. Moreover, targeting convenience stores and trol, “microgrids” used as regional grids, and “smart distribution businesses, one-stop integrated solutions grids” as the energy infrastructure. Energy and infor- are also provided for the construction of energy-saving mation fl ow in both directions between each of these stores. layers to realize optimal energy operation in smart With a smart grid, these EMSs and an upper-layer grids and smart communities. community EMS are hierarchically linked on the same (1) Power devices and power electronics equipment information platform. Fuji Electric supplies power electronics equipment A two-way interconnection with an upper level such as uninterruptible power supplies (UPS) and EMS or power company is realized via “smart meters” high-current DC power supplies for which Fuji Electric installed in homes and at other small-scale end-users. has a high market share worldwide, powertrains for A smart meter, in addition to having a conventional electric vehicles, transport and conveyance systems, real-time metering function of the cumulative power etc. Additionally, a new 3-level conversion circuit that consumption, also has an information display terminal uses Fuji Electric’s proprietary reverse blocking IGBT that continuously exchanges information with an up- (RB-IGBT) has been developed, and achieves 30 to 40% per level EMS, and implements a demand response lower loss than a conventional circuit. function, which according to the supply and demand Power electronics in smart communities is applied status of power companies, varies the selling price of over a wide range of fi elds including, for example, electricity and induces load control for the end-user. power conditioners for solar power generation systems, (3) Microgrids power storage systems for the effective utilization of For the introduction and evaluation of microgrids surplus renewable energy, reactive power compensa- on remote islands, many projects are planned or are tors and voltage regulators for maintaining the power underway, both in Japan and overseas. grid voltage at a proper level, etc. At present, a large number of diesel generators are used for supplying power to remote islands, and mitigating the high generation cost resulting from fuel

Smart community transportation costs and reducing the environmental Water and sewage utilities, etc. load are challenges. The remote island demonstration projects aim to resolve, through the coordinated op- Transportation system eration of existing diesel generators and power storage Smart grid Substation Distribution system systems, the problem of supply/demand imbalance and to maintain the power quality of the power grid when

Microgrid Energy information solar power, wind power, or other type of renewable Energy information energy is adopted in large quantities.

End-user’s Energy In 2009, Fuji Electric delivered a total of nine mi- information grid crogrid demonstration systems to remote islands in the Kyushu and Okinawa regions.

Power electronics Energy equipment information (4) Smart grids As a participant since 2010 in the “Next-Genera- Power device Energy tion Energy and Social Systems Demonstration Proj- information ect” of the Japanese Ministry of Economy, Trade and Industry, Fuji Electric is working on the development and demonstration of a cluster energy management Fig.5 Structure of a smart community system (CEMS).

114 Vol. 57 No. 4 FUJI ELECTRIC REVIEW Figure 6 shows the characteristics of the CEMS that Fuji Electric is working on. Targeting the export- 4.1 Engineering, procurement, construction (EPC) skill ing of new urban energy infrastructure to emerging na- A smart community project, especially when ex- tions, this demonstration project evaluates the utiliza- porting infrastructure, requires a business scheme for tion of renewable energy and local industrial resources, providing total solutions, from planning to construc- the potential contribution to large-scale interconnected tion and operation. Accordingly, as the project struc- power grids, as well as the usefulness and profi tability ture, collectives consisting of suppliers, developers, thereof. Additionally, for local end-users to contribute engineering fi rms, constructors, operators and main- to supply/demand operational management for energy, tenance workers, fi nance companies and the like are leading research of demand response, various incen- expected to be increasingly formed and advanced by tives, and the like is also planned. domestic Japanese companies and regional overseas Furthermore, since 2009, in NEDO’s “Smart Power companies. Network Research,” Fuji Electric has also been in- In order for Fuji Electric to play a major role in volved in the development and demonstration of com- these collectives, the “EPC skill” level must be en- ponent devices and distribution control systems for hanced so as to provide a one-stop solution capable of next-generation distribution systems. aggregating the resources of the group companies and (5) International standardization strategy performing the engineering, procurement and con-

In international standardization activities concern- struction work for the energy infrastructure. feature issue: Smart Community ing smart grids and smart communities, Europe and North America have a slight lead at present. The glob- 4.2 Safety and security in the construction of public infra- al deployment of distinguished domestic technologies is structure an important part of the international standardization A smart community oversees the efﬁ cient opera- strategy. Focusing on power electronics, smart meters, tion of not only the energy infrastructure but also the and the EMS ﬁ eld, Fuji Electric is increasing its partic- public infrastructure, which includes water, sewage ipation in various standardization activities, including and waste treatment systems, transportation systems the Japan Smart Community Alliance established by and so on, for an entire city and requires robustness as the Japanese Ministry of Economy, Trade and Indus- a lifeline for city functions in the case of a disaster, and try and NEDO. also requires know-how for incorporating substantial safety and security features. 4. Future Challenges Possessing technology and know-how relating to the protection and control of power distribution equip- The main markets for smart community public ment and large-scale plants, Fuji Electric positions infrastructure projects exist in urban development and these safety and security technologies as important urban regeneration projects overseas. As a supplier distinguished items in its lineup of smart community of component and system products, Fuji Electric is ex- products. pected to face the following challenges in expanding its business. 5. Postscript

Smart communities are mostly still in the planning Large-scale power system Coordinated interconnection with large-scale system and demonstration stages. As solar cells and electric ™Power quality management ™New energy output stabilization vehicles come into widespread use in the future, the ™System interconnection Utilization of protection equipment construction and operating costs for smart grids will renewableenergy Cluster energy become comparable to those of large-scale power grids, management system (CEMS) and the full-scale launching of the smart grid market Solar User participation is expected. Biomass Electric power storage Aiming to provide a safe and secure low-carbon en- system Wind power ergy infrastructure, Fuji Electric intends to strive for Fuel cell further technical innovation and thanks all concerned ™Energy management system for buildings and homes parties for their guidance and cooperation. Waste heat ™Smart metering generation User ™Demand response References (1) World Energy Outlook 2008, International Energy Fig.6 Characteristics of cluster energy management Agency.

Present Status and Future Outlook for Smart Communities 115 Fuji Electric’s Efforts Involving Next-generation Energy and Social Systems Yutaka Fueki † Jimpei Kuwayama †

ABSTRACT

In order to realize the “Fuji Smart Network System” as a next-generation energy and social system, Fuji Elec- tric aims to realize power stability, energy savings and reduced carbon emissions in a targeted area by employing geographical distribution, and to construct a system that does not affect power transmission systems. The system aims to resolve energy-related problems within each region by addressing, through region-wide initiatives, increased voltage resulting from the adoption of large amounts of solar power, energy conservation by direct and indirect load control using smart meters, and the interchange of heat and gas or other energy sources. Fuji Electric is participating in planning for Kitakyushu City and Keihanna Science City in Japan, and having been commissioned by NEDO, is conducting a basic survey for overseas.

1. Introduction tion in demonstration projects are described.

To achieve a low carbon society, the adoption of 2.1 Defi nitions renewable energy, electric vehicles (EV), energy saving (1) Smart grid homes, zero-emission buildings, and the introduction of To resolve the power quality-related issues that ac- high effi ciency equipment in factories have been stud- company the large-scale introduction of renewable en- ied extensively. Recently, in addition to the introduc- ergy, a smart grid provides an information network for tion of stand-alone energy-saving and energy-creating controlling power and performs real-time adjustments equipment, efforts aiming to utilize bidirectional com- of the supply and demand of energy, and the following munication, such as with a smart meter, in order to benefi ts can be obtained as a result. utilize energy effectively throughout a region have (a) Stable utilization of power is ensured and the been attracting attention. risk of a large-scale power outage is reduced In Japan, region-wide optimal energy management (b) Energy savings and effi cient energy utilization that includes electric utilities, companies that gener- are promoted integrally with customers ate renewable energy, and consumers, the effective (c) Optimization of electric power facility mainte- utilization of not just electrical energy, but also heat, nance and management gas and the water environment, as well as demonstra- (2) Smart communities tion projects for creating eco-friendly urban spaces and A smart community is a new type of “city plan- transforming consumer lifestyles are being promoted. ning” that aims to achieve a low carbon footprint as Overseas, infrastructure improving projects for electric well as increased convenience for its residents and to power, heat, gas, the water environment, transporta- foster urban renewal. Smart communities are next- tion and the like are actively being carried out for cit- generation type local communities and are built using ies and industrial parks. the latest technologies, such as smart grids. Smart Fuji Electric is participating in projects to con- communities are formed by creating living spaces that struct a next-generation energy and social system in achieve both improved comfort and energy savings Japan in order to create a smart community that is an through the effective utilization of energy, the intro- eco-friendly city, and is also actively conducting a sur- duction of renewable energy, and the renovation of vey of overseas smart communities. transportation systems, and the information networks that link these smart communities also play an impor- 2. Next-Generation Energy and Social Systems tant role.

Below, deﬁ nitions of a smart grid and smart com- 2.2 Fuji Electric’s vision of next-generation energy and munity are presented, and national initiatives and social systems demonstration projects for next generation and energy Fuji Electric aims to build a geographically-distrib- and social systems, as well as Fuji Electric’s participa- uted type next-generation energy and social system that achieves power stabilization, energy savings and † Fuji Electric Co., Ltd a smaller carbon footprint for a target region, and that

116 does not negatively affect the power distribution sys- 2006, for the purpose of demonstrating these technolo- tem. gies, a “Regional Energy Management Development The next-generation energy and social system aims and Complex Storage System Technology Development to resolve energy-related problems within each region Project” was made public, and demonstration projects by addressing, through region-wide initiatives, the in- of the next-generation energy and social system were crease in voltage resulting from the adoption of large decided to be carried out for 5 years beginning in 2010 amounts of solar power, and to realize energy conser- in Kitakyushu City, Keihanna Science City, Yokohama vation by direct and indirect load control using smart City and Toyota City. meters, and the interchange of heat and gas or other energy sources. 2.4 Fuji Electric’s participation in demonstration projects Figure 1 illustrates Fuji Electric’s concept of a Sharing a vision of the future with national and geographically-distributed type next-generation energy local governments, Fuji Electric is participating in and social system. This concept is fundamental to the demonstration projects and offering various proposals “Fuji Electric Smart Network System,” to be described to promote development both in domestic and global later, and is applied to smart grids and smart commu- scale. nities. Fuji Electric has participated in the following recent demonstration projects.

2.3 National initiatives and demonstration projects (1) Smart grid-related demonstration projects feature issue: Smart Community Japanese national initiatives include the mass (a) Kyushu and Okinawa isolated island micro-grid adoption of renewable energy centered mainly on so- demonstration system (2009) lar power (targeting 28 GW of solar power generation (b) Next-generation optimizing control technique and 4.9 GW of wind power generation by 2020), direct experimental project for energy transmission and indirect load control through bi-directional com- and distribution systems (2010) munication using smart meters (targeting installation Voltage control of centralized-type next-genera- in all homes by 2020), the application of storage cell tion power distribution automation system technology as represented by electric vehicles, and (c) Fuel cell system for commercial buildings in a the support of the overseas exporting of infrastructure US-Japan smart grid demonstration project in based on the new technologies acquired here. In June New Mexico (2010) (d) Demonstration of effect of introducing load balancing equipment (2011) Indirect and direct load control using smart meters Power station Issues (2) Smart Community-related demonstration projects ™Increased voltage resulting from adoption of Thermal power large amounts of distributed power sources (a) Next-generation energy and social system dem- Hydropower ™Energy savings through direct and indirect onstration (2010) Nuclear power load control ™Interchange of waste heat and hydrogen, etc. (i) Kitakyushu city Distribution substation Solution ™Regional energy management system devel- ™Autonomous securing of energy opment project demand and supply suited to the characteristics of the region ™Complex storage cell system technology aiming for low carbon emissions development project and power stabilization Power transmission system (ii) Keihanna Science City Target region ™Complex storage cell system technology Distribution substation development project Locally installed (b) Study of feasibility of introducing smart commu- storage cell & PCS nity technologies to an industrial park in Java, Cluster energy Step-down to 6.6 kV management Indonesia (2010) system(CEMS) Pole mounted transformer 3. Fuji Electric’s Efforts Step-down from6.6 kV Consumer Factory to 200/100 V The targeted scale, power quality, energy manage- (FEMS) Power stabilizing ment and local production for local consumption are Smart Commercial equipment building four essential perspectives for next-generation energy meter (BEMS) and social systems. Based on these perspectives, Fuji Household Electric’s technologies that contribute to lower carbon Retail store Rapid charging Distributed (REMS) station emissions and improved power stabilization are de- power sources scribed, and demonstration projects, both in Japan and overseas, that apply these technologies are introduced Fig.1 Fuji Electric’s regionally distributed next-generation below. energy and social system

Fuji Electric’s Efforts Involving Next-generation Energy and Social Systems 117 3.1 Four perspectives and the corresponding technolo- Through the effi cient utilization of electric pow- gies er and heat by consumers, i.e., households, charging Fuji Electric has been involved in developing and stations, stores, commercial buildings and factories, delivering next-generation energy technologies and and the utilization of information networks to ac- social systems for many years. These technologies quire information in real-time, energy management have included, for example, distribution automation aims to cross-utilize energy within a region. systems, power system control systems, energy man- (d) Local production for local consumption agement systems (EMS), distributed power sources, Energy control of a target region is implemented balancing control, power quality stabilization, power in collaboration with the power transmission sys- instruments, power distribution equipment, and in- tem, regional cogeneration system, distributed pow- verters, converters and the power conditioners (PCS) er source system and the like, and aims to achieve to which they are applied. local production for local consumption. In recently requested social infrastructure-related Based on these four perspectives, Fuji Electric’s projects in Japan and overseas, in addition to higher technology to be utilized in the next-generation energy effi ciency and optimization through managing, moni- and social system is classifi ed as carbon emissions- toring and controlling the entire energy supply chain, lowering or power stabilizing as shown below. from supply to delivery to the consumer, the informa- (1) Carbon emissions-lowering technologies tion networks that provide support have also become (a) Cluster energy management systems (CEMS) essential elements. that manage entire energy in the targeted re- Fuji Electric is approaching the next-generation gion energy and social systems from the following four per- (b) Retail, building and factory energy management spectives. systems (REMS, BEMS, and FEMS) that target (a) Targeted area the consumer Various sizes exists, but compact cities, indus- (c) Smart meters and wireless multi-stage relay trial complexes, industrial parks, islands, and non- technology provided with customer power usage electrifi ed areas are targeted. prehension, stop and release, guidance display (b) Power quality and response input functions So as not to adversely affect the power transmis- (d) Technology relating to distributed power sources sion system, fl uctuations in voltage and frequency such as lightweight fl exible fi lm-type solar cells, caused by distributed power sources that have been commercial 100 kW phosphoric acid fuel cells, installed in a targeted region are to be absorbed micro tubular turbines for low-head hydropower within the targeted region to stabilize power. generation, and binary geothermal power gen- (c) Energy management eration that effi ciently converts low-temperature

Power station Local micro-grid Hydrogen Local micro-grid Thermal power Power stabilizing equipment Fuel Heat Storage Wind-generated Hydropower cell cell power Locally installed storage cell Nuclear power Power system monitoring and GE control systems Local power station PCS INV SVC PCS

LRT Load dispatching Regional energy Next-generation distribution management system automation systems center LBC PCS IT switch INV PCS Area-type power SVR stabilizing Mega Solar equipment Wind farm Storage Smart house Customer’s system cell Smart LRT: Load Ratio control Transformer meter Solar REMS PCS PCS UPS SVR: Step Voltage Regulator power Charging BEMS SVC: Static Var Compensator generation device FEMS LBC: Loop Balance Controller GE Load PCS: Power Conditioner Fuel Storage Solar power Gas generation UPS: Uninterruptible Power Supply Heat cell engine cell INV: Inverter REMS: Retail Energy Management System BEMS: Building and Energy Management System Retail storeFactory Commercial building FEMS: Factory Energy Management System

Fig.2 Overall view of the “Fuji Smart Network System”

118 Vol. 57 No. 4 FUJI ELECTRIC REVIEW thermal energy into electrical energy tem, and is conducting fi eld demonstrations in Japan (2) Power stabilizing technologies and overseas. The results of these projects are incor- (a) Next-generation power distribution system tech- porated into a compact “Social Infrastructure Package nology provided with functions for fault point Focused on Electric Power,” and application is being detection and recovery, power fl ow monitoring, promoted to: (1) environment friendly cities and smart and voltage and frequency adjustments. communities, (2) industrial complexes where high lev- (b) Technology relating to high-effi ciency power con- els of energy integration exist, and (3) isolated islands ditioners (PCS) and power stabilization equip- and non-electrifi ed areas where there are low levels of ment to control the discharging and charging of energy integration. locally installed storage cells as equipment for implementing power control within a grid 3.2 Demonstration projects in Japan (c) Technology relating to load ratio control trans- (1) Next-generation energy and social system demon- formers (LRTs), IT switches, static var compen- stration projects sators (SVCs), step voltage regulators (SVRs) (a) Regional energy management and uninterruptible power supplies (UPSs) Fuji Electric is participating in the development which, as distribution equipment, aim to stabi- of a “regional energy management system focused lize the on-grid power quality on regional energy-saving stations” in Kitakyushu-

(d) Micro-grid technology and balancing control city, and is promoting urban development that aims feature issue: Smart Community technology for performing high-speed optimized to achieve lower carbon emissions in the Higashida control of energy supply and demand in a closed district of Kitakyushu-city. grid as in the case of isolated islands This district is an advanced model district for The linking of these technologies is shown in the energy supply and demand, and aims to become a overall view of the Fuji Smart Network System in Fig. local community in which energy saving behavior is 2. incorporated into daily life and business activities. Fuji Electric has developed essential products and The relevant technologies for reducing the car- technologies for realizing the Fuji Smart Network Sys- bon footprint and controlling all the energy utilized

Cogeneration facility

Private line power system Electricity

Information network Housing complex Electricity Mega solar Fuel cell Environment museum Heat HP Power system Electricity Electricity Heat Heat Commercial-use storage Fuel cell fuel cell Heat Heat Wind-generated BEMS storage HEMS power facility

Commercial facility Hydrogen supply Eco-club house Electricity Electricity

Heat Heat Heat HP storage Hydrogen BEMS BEMS

Hydrogen

Total energy management Hydrogen Measurement storage (electric power, heat, hydrogen) Operating plan Regional energy Demand / supply balance control Hydrogen station management system Power system linking Locally installed storage cell BEMS: Building and Energy Management System HEMS: Home Energy Management System HP: Heat Pump

Fig.3 Overall view of Kitakyushu City next-generation energy and social system

Fuji Electric’s Efforts Involving Next-generation Energy and Social Systems 119 in the district include linking technology for renew- the system confi guration of a regional energy manage- able energy and cogeneration systems, technolo- ment system. gies for supplying power to electric vehicles and for (b) Demand-side energy management utilizing power from discharging electric vehicles, In support of the next-generation energy and power stabilizing technology that utilizes locally social system for consumers, Fuji Electric is partici- installed storage cells, technology for visualizing the pating in the “development of an energy controller energy consumption of each consumer, and demand for a facility grid” in Keihanna Science City, and is suppression measures based on dynamic pricing and advancing demonstration projects for technologies an eco-point system. In the demonstration project, that lower carbon emissions of complex buildings, as shown in Fig. 3, energy suppliers and consumers including rental offi ces, halls, hotels and restau- in the targeted region are connected to an informa- rants. tion network, and a regional energy management This demonstration project has the following two system measures the supply and demand of electric objectives. power, heat and hydrogen, creates an operating (i) By installing storage cells, solar cells, fuel plan, controls demand and supply, and incorporates cells and smart meters within a complex the power systems. The results of this demonstra- building, which is considered to be a single tion project, in terms of comprehensive energy man- closed grid, and utilizing the storage cells, agement, are expected to be used as a model case of fuel cell and heat pumps effi ciently, the proj- an environment-friendly compact city that will be ect aims to achieve the effect utilization of the deployed overseas in the future. renewable energy and heat within the build- The regional energy management system being ing. developed to reduce carbon emissions in this dem- (ii) By promoting energy savings and reduced onstration project has the following three character- carbon emissions through indirect load con- istics. trol, and enhancing the environmental aware- (i) The system acquires, through a dedicated line ness of tenants and other building users, or general acquisition procedure, and cen- the project aims to contribute to the goal of trally manages comprehensive energy data achieving zero emissions for the entire com- required for regional energy management plex building. according to the need (high-speed response, Fuji Electric is also moving forward with verifi ca- frequency, etc.) for that data. tion of the control method for achieving the specifi ed (ii) Multiple independent systems can be in- target value of demand through linking information stalled, according to requirements of the tar- with the regional energy management system for Kei- geted region, in order to implement control hanna Science City. requiring real-time performance such as for Demand-side energy management is realized by power generation, charge and discharge com- installing a compact building-use energy controller in mands, ascertainment of energy utilization a complex building. This controller directly controls for each consumer, and business processes energy devices such as storage cells and fuel cells in such as energy demand and supply planning a complex building, and through a smart meter, also (iii) Acquired information is provided to an external service provider so that new services can be created. Service provider Service provider Other system Consumer Storage Table 1 lists the main functions and Fig. 4 shows Weather Electric behavior cell asset information utility analysis, etc. management Table 1 Functions of a regional energy management system Standardized I/F 2 Standardized I/F 2

Regional energy management system

Comprehensive energy management for an entire Energy data for Customer data for region, combining energy demand forecasting and Operating plan service provider service provider weather forecasting, power system control at the Power system linking time of adoption of new energy, storage cells Customer usage status Demand-side management Demand/supply balance control and EVs Power generation and charging/discharging control Data Stabilization through coordinated operation with Total energy data (electric power, heat, hydrogen) aggregation

the power system Real-time acquisition and control Standardized I/F 1 Standardized I/F 1 Power generating and storing facility Real-time ascertainment of energy usage status for Consumer Functions Power generating Power generating each customer facility facility Smart Transmission package Transmission package Transmission package Demand-side management through customer load PCS BEMS HEMS Concentrator control and dynamic pricing Solar power/ wind power/ Smart Smart Storage Smart Storage Standard procedure for connecting to customers fuel cell PCS meter cell meter cell Smart meter and energy equipment Creation of new services by utilizing energy consumption and CO2 visualization data Fig.4 Conﬁ guration of a regional energy management system

120 Vol. 57 No. 4 FUJI ELECTRIC REVIEW performs indirect load control for the tenant. Through reactive power adjustment and power storage func- linking to building management systems centered on tions will be utilized both in Japan and overseas. Fig. conventional monitoring or visualization, the energy 6 shows a comprehensive view of optimal voltage con- usage within a building can be made even more effi - trol technology. cient. Table 2 lists the main functions of building-use energy controllers, and Fig. 5 shows a system confi gu- 3.3 Demonstration projects overseas ration. Fuji Electric, Sumitomo Corporation, Mitsubishi (2) Demonstration project of optimal control technol- Electric and Tokyo Electric Power Services Co., Ltd. ogy for next-generation power transmission and have been commissioned by the New Energy and In- distribution systems dustrial Technology Development Agency (NEDO) to One technical challenge for smart grids is how conduct a basic survey of power infrastructure exports to prevent a voltage increase when many distributed that utilize smart technology and that target South- power sources including solar cells are connected to east Asian industrial parks where a high level of ener- the power distribution system. To overcome this chal- gy integration exists and where greater energy savings lenge, Fuji Electric has for many years advanced the and lower carbon emissions are anticipated. development of equality control for voltage suppres- Industrial parks in Southeast Asia are experienc- sion with solar power generation and the like. Next- ing an infl ux of Japanese companies and have the fol-

generation distribution automation systems overcome lowing characteristics. feature issue: Smart Community this challenge by utilizing centralized control of power (a) Power quality at a level equivalent to that of Ja- conditioners connected to voltage regulators and solar pan is requested for stable manufacturing cells from the central monitoring and control systems. (b) Compared to Japan, the energy management of In the power distribution sector, as preparation for plants has much room for improvement in terms the introduction of a large number of distributed power of energy conservation and reduction of carbon sources, next-generation distribution automation sys- emissions tems provided with a centralized control function (c) The amount of contracted electrical power cor- for voltage regulators, and distributed generator-use responds to the amount of power managed by power conditioners equipped with power stabilizing, a single power distribution substation, and is similar in scale to that of the district targeted for energy management Table 2 Functions of an energy controller for buildings In light of these three characteristics, among the Energy controller for buildings smart grid technologies being developed for next-gen- Load leveling with storage cells eration energy and social system demonstration proj- (peak cut, peak shift) ects, the technologies for lowering carbon emissions Control and operation of storage cells (power) and heat pumps (heat) and improving power stability listed in Table 3 are Indirect load control via smart meters at customer thought to be applicable to Southeast Asian industrial Functions sites parks. Charging control based on EV operating plans Aiming to reduce carbon emissions and improve Utilization of waste heat from fuel cells power stability of Southeast Asian industrial parks, Coordinated control with air conditioning Fuji Electric intends to apply these smart grid tech- Achievement of targeted demand with regional nologies to build an industrial park power supply in- energy management frastructure. Fig. 7 shows a system model in which smart grid technology has been applied to an industrial park. Regional energy management system Targeted demand 6.6 kV power system value Complex building The problem of rising voltage that occurs due to the phenomenon of reverse Conventional Energy Solar power power flow caused by the deployment of large amounts of solar power building generation Tenant generation can be resolved through optimized centralized control of voltage controller regulators and power conditioners (PCS) for solar cells. management Customer’s system for buildings Display internal Information smart meter Next-generation distribution automation system network System status assessment (power flow calculation, status estimation) Calculation of optimum controlled variable Smart Rapid Air Fuel Heat (optimization method) charging Direct control of voltage regulators and PCSs for solar cells PCS device conditioner cell pump

Storage cell SVR LRT Pole mounted PCS PCS SVC Energy is utilized effectively within a complex building transformer Low voltage High voltage Low voltage Low voltage load load load load Fig.5 Conﬁ guration of demand-side energy management system for complex buildings Fig.6 Overall view of optimal voltage control technology

Fuji Electric’s Efforts Involving Next-generation Energy and Social Systems 121 Table 3 Smart grid technology suited for industrial parks

Carbon reduction technology Power stabilization technology Factory energy management Peak-cut/demand control Uninterruptible power supply (UPS) Direct/indirect load control Emergency in-house power generator Automatic measurement with smart meters Factory Static var compensator (SVC) Changeover to high-efﬁ ciency equipment Step voltage regulator (SVR) Renewable energy equipment Power capacitor Inverter control, air conditioner control Information network within the factory Regional energy management Emergency power supply system Peak-cut/demand control Power quality stabilizer Industrial Direct/indirect load control Static var compensator (SVC) park Renewable energy equipment Step voltage regulator (SVR) Information network within the industrial park Distribution automation system within the industrial park

Substation Power utilities Industrial park Power 150 kV 20 kV Reactive power Factory Automatic compensator capacitor Solar power generation switch Smart Automated voltage (roof-based installation) meter regulator

Centralized control center FEMS High quality power line

Central load dispatching center Factory High quality power line Power quality stabilizer Industrial park Office Distribution automation system Factory Solar power generation (roof-based installation) FEMS-GW

Factory Industrial park EMS Storage cell Solar power generation (ground-based installation)

Fig.7 System model of smart industrial park

This model assumes that the district targeted for re- overseas demonstration projects. The net result is gional energy management is the entire industrial the compilation of a next-generation energy and social park, and with an energy management system, stabi- system that aims for lower carbon emissions and im- lizes power for the entire industrial park, saves energy proved power stabilization for consumers and targeted and cuts peak power demand. The two main technolo- regions. gies utilizes are listed below. Fuji Electric will develop this system for consum- (a) A “power quality stabilization device” installed ers who are seeking energy savings and more effective at the industrial park supplies a high quality utilization of electricity and heat energy, and also for power source to multiple factories designated energy districts and local governments pos- (b) An “industrial park EMS” performs centralized sessing a vision of new energy utilization. For power control of factory demand restraint and energy companies, with the aim of improving stability and management increasing the quality of power, Fuji Electric is promoting the introduction of next-generation distribution 4. Future Challenges automation systems to meet year 2020 targets (solar power generation of 28 GW, wind power generation of The ongoing demonstration projects described in 4.9 GW, and smart meters installed in all homes). section 3 are all component elements of the Fuji Smart Overseas, Fuji Electric is aiming to develop this Network System, and this system will be completed system as a “social infrastructure package focused on initially by leveraging the results of Japanese and electrical power” that combines carbon-lowering tech-

122 Vol. 57 No. 4 FUJI ELECTRIC REVIEW nology and power stabilization for smart communities, 5. Postscript industrial parks, islands, as well as the power distribution sector. The infrastructure for a smart community In the future, it is expected that solar cells and is required to consist of not only an energy infrastruc- smart meters will be used in many homes, distributed ture, but also a water environment infrastructure, an power sources and high efﬁ ciency devices that aim to infrastructure for electric vehicles including the capa- reduce carbon emissions will be encouraged and elec- bility to control the status of charging device and the tric vehicles will become widespread. Fuji Electric like, and an information infrastructure. Fuji Electric possesses many technologies relevant to the smart will proceed to construct this system by linking it to grids that will be utilized in Japanese society in the water treatment systems and retail store systems that near future. In response to social requests concern- have been developed over many years. ing smart grids and smart communities, Fuji Electric Moreover, because the business areas targeted by will expedite the commercialization of the results of next-generation energy and social systems are new technical development and demonstration projects of service areas, the proﬁ tability of companies that have the next-generation energy and social systems, and a next-generation energy and social system and compa- intends to contribute to the establishment of a social nies that operate and maintain systems are important, infrastructure for developing environment friendly cit- and Fuji Electric intends to participate from the busi- ies and regions, adopting large amounts of renewable

ness feasibility study and basic planning stages. energy, and popularizing electric vehicles. feature issue: Smart Community

Fuji Electric’s Efforts Involving Next-generation Energy and Social Systems 123 Microgrid System for Isolated Islands

Takehiko Kojima † Yoshifumi Fukuya †

ABSTRACT

There are many inhabited isolated islands throughout the world and most of these operate with independent power systems. Because such power systems located on small isolated islands are small in size and their generators have low inertial energy, they are sensitive to ﬂ uctuations in the output of renewable energy. To solve this problem, Fuji Electric has studied the conﬁ gurations of microgrid systems for isolated islands and the challenges for isolated systems when introducing a large amount of renewable energy, and also has examined ways in which to best address those challenges. This paper describes the challenges and solutions for the application of microgrid systems to small isolated islands and also presents an overview of demonstration projects being carried out on six islands in Kyushu and three islands in Okinawa.

1. Introduction characteristics . (a) Applicable to special regions where multiple To address global environmental issues including consumers exist the reduction of greenhouse gas emissions, the creation (b) Confi gured from distributed power sources and of a framework and the setting of goals on a global a small-scale power supply network scale are being examined. In this context, the adoption (c) Onsite power supply system capable of operat- of renewable energy is considered to be effective both ing separately from a pre-existing large-scale for resolving environmental issues as well as fostering power supply system new industries, and future developments are expected. (d) Confi gured as either a system linked-type that Meanwhile, the mass adoption of renewable energy is linked to the power system, or an indepen- raises concerns about possible deleterious effects on dent-type separate from the power system the power system. (e) Typically uses Information and Communication Since the latter half of the 1990s, countries of the Technology (ICT) for integrated control of mul- European Union (EU) have advanced the adoption of tiple distributed power sources and loads large quantities of wind power in order to tackle global As an interchange power supply system that uses environmental issues, but various system problems renewable energy, this type of small-scale system is have become evident and a solution is urgently needed . an environment friendly power system that, because it Since 2009, Fuji Electric has studied microgrid contains equipment for storing energy and heat, is able system confi gurations for isolated islands, the issues to absorb the fl uctuations in demand and output aris- involving independent systems when large amounts ing from renewable energy within the region, and is of renewable energy are introduced, and methods for expected to come into widespread use as a system that resolving those issues. is compatible with existing systems and that does not This paper presents an overview of the control negatively affect pre-existing power sources. functions and the types of equipment that are installed when applying these microgrid systems to isolated is- 2.2 Goals and issues in the application of microgrids to lands. isolated islands An isolated island microgrid system is a special- 2. Application of Microgrids to Island Power ized small to medium-sized independent power system Systems that inherits the original microgrid characteristics and that aims to maintain the quality and to ensure the re- 2.1 Microgrid system liability of power in an independent system when large A microgrid system uses multiple distributed pow- amounts of renewable energy are introduced. er sources and operates a power supply system while Countless inhabited islands exist worldwide, the maintaining a regional balance between power demand majority of which are supplied with electric power by and supply. A microgrid system has the following independent systems. Japan has the largest number of isolated-island independent power systems of any † Fuji Electric Co., Ltd country.

124 In independent power systems for isolated islands, ability of the power system, and measures to reach a due to problems with operational constraints and the solution are needed. The challenges when renewable like, power is typically supplied from internal combus- energy is adopted by an isolated island are listed in tion power generators, which use fossil fuel and have a Table 1. relatively large CO2 emission factor. Additionally, the The introduction of a microgrid system provides an transportation of fuel to remote areas adds to the cost effective resolution for the various issues of concern in of power generation, and economic effi ciency is an is- the case of a mass adoption of renewable energy at an sue for isolated islands. isolated islanded. The mass adoption of renewable energy, without requiring fossil fuels, by isolated islands is thought to 3. Isolated Island Microgrid Systems provide the solutions of both reduced environmental load and improved economic effi ciency. 3.1 Basic confi guration The mass adoption of renewable energy, however, Figure 1 shows the basic confi guration of an iso- leads to a decrease in power quality and supply reli- lated island microgrid system. The system, which consists of an existing internal-

Table 1 Challenges for adopting renewable energy on combustion power generation system and renewable isolated islands energy and electric power storage systems, measures

with a sensor the generated power and power quality feature issue: Smart Community Item Challenge assessment items (frequency, reactive power, etc.) and Supply/ Balance between supply and demand must be demand maintained at all times (allowable fl uctuations sends the measured values via a high-speed transmis- operation are within range of the governor following sion path to a microgrid control system. management capability for pre-existing generators) A small-scale system operates mainly with small Frequency Renewable energy and load fl uctuations cause capacity internal combustion generators having low and voltage large and instantaneous changes in sustainability frequency and voltage inertial energy and is susceptible to decreases in power Reserve power is extremely low (because the quality due to instantaneous fl uctuations in frequency Reserve power generator unit capacity is small) or the like caused by outages or abrupt changes in the If suffi cient reserve power (increased margin) output of renewable energy. The control device (gov- is provided to compensate for the amount of Economic fl uctuation in renewable energy, the diesel ernor control) of an existing system is unable to follow feasibility generators will operate at a point of low output such abrupt changes, and unless countermeasures are and the fuel effi ciency will decrease. implemented, the frequency may deviate from the pre-

Existing power plant Existing power distribution system

Power distribution system G Sensor Sensor

No.1. Diesel power generator Power distribution system

G Sensor Fuel storage amount No.2. Diesel power generator Weather observation information

G Sensor Sensor information No.3. Diesel power generator Sensor Remote monitoring system

Generator information Microgrid control Communication I/F system Communication I/F PC for monitoring VPN

Communication I/F Communication I/F Sensor Sensor

Wind power generation

Sensor Charging/ discharging inverter

Solar power Storage device A Storage device B generation Energy storage system

Fig.1 Basic conﬁ guration of isolated island microgrid system

Microgrid System for Isolated Islands 125 Power distribution system Instantaneous power compensation control function Dead zone + Active power Calculation of Instantaneous fluctuation compensation control command active current +

(instantaneous value) Overload limiter Calculation of + – 1 + active power 1+Tf – (Effective Ra value) Storage cell storage quantity control function Calculation of amount + Calculation of variable Storage cell SOC* control Variable time constant of SOC* compensation + internal limiter

Storage cell Storage cell SOC* Calculation of variable breakdown time constant Output fluctuation compensation control function

Storage cell information * SOC: State Of Charge

Fig.2 Conﬁ guration of control function for a small-scale isolated island system

able energy increases, stable operation within the op-

Frequency Generator active power Load active power PCS output erating range of the existing generators will be difﬁ cult to maintain, and measures such as peak shifting by 60.5 160 controlling the output of the renewable energy, adding 60.0 120 redundant electric power storage systems and increasing capacity are needed. 59.5 80 Additionally, in the case of an isolated island sys- 59.0 40 tem of about 1,000 kW (a medium-scale isolated island

Frequency (Hz) Active power (kW) system), the system operates mainly by controlling 58.5 0 0 5 10 15 20 multiple internal generators, and a wide operating Time(s) range can be set if there is a sufﬁ cient margin of re- (a) With instantaneous power compensation function serve power. Thus, a microgrid system is able to realize the most economical system conﬁ guration within

Frequency Generator active power Load active power PCS output the control range of pre-existing generation equipment.

60.5 160 3.2 Control functions in a small-scale isolated island sys- 60.0 120 tem Fuji Electric has commercialized its “UPS 8000 G” 59.5 80 series of uninterruptible power supplies that are 59.0 40 equipped with an absorber function for assisting the Frequency (Hz)

Active power (kW) load-following performance when a load is applied to 58.5 0 0 5 10 15 20 a high-effi ciency gas engine generator. These uninter- Time(s) ruptible power supplies sense instantaneous fl uctua- (b) Without instantaneous power compensation function tions in the load and are able to provide instantaneous fl uctuation compensation of approximately several mil- Fig.3 Suppressive effect of frequency fl uctuation by instanta- liseconds to 10 ms. In addition, a demonstration tests neous power compensation for stabilization equipment that aims to suppress output fl uctuations of wind farm has been underway scribed value and the power quality of the system will since 2008 at the Nishime Wind Farm operated by deteriorate. Win-power Co., Ltd. (a wholly owned subsidiary of In the case of an isolated island system of about Fuji Electric). several hundred kW, these instantaneous frequency As a result of the demonstration tests, stabiliza- fl uctuations tend to become noticeable, and a high- tion technology and technology for the operation and speed function for compensating for these fl uctuations management of storage devices has been established. is needed. Furthermore, on a small-scale isolated is- Based on these technologies, a microgrid control func- land, the number of generators in operation is few, and tion for small-scale isolated island systems was devel- the operation can only be adjusted over a small range. oped. Thus, if the percentage of power generated by renew- Figure 2 shows the confi guration of a control func-

126 Vol. 57 No. 4 FUJI ELECTRIC REVIEW tion for a developed small-scale isolated island system. characteristics, the cycle life, required space for instal- This control function enables control to be imple- lation, and the economic effi ciency. mented in response to instantaneous fl uctuations due In general, for load balancing purposes, such as to wind turbine cut-out, outages of photovoltaic power peak shifting, larger capacity storage devices are re- conditioner and the like, without deviating from the quired, and storage cells having a relatively high volu- system frequency. Fig. 3 shows the results of simula- metric energy density are advantageous. tions comparing the cases with and without the instan- On the other hand, for fl uctuation compensation taneous power compensation function. purposes, various storage devices are considered for application. As a stabilization measure for relatively 3.3 Control functions in a medium-scale isolated island short-period fl uctuations lasting several minutes or system less, a capacitor is advantageous in terms of cycle life In a medium-scale isolated island system where and volumetric power density. Moreover, for the com- multiple rotating-type electric power generators are pensation of long-period fl uctuations lasting several operating at all times, a certain amount of transient tens of minutes or more, various types of storage cells, fl uctuation is absorbed by the inertial energy of the including new batteries such as lithium ion batteries generators. In such a system, the generators are able and the like, are applied. to operate over a relatively wide range, and the selec- Fuji Electric has verifi ed the application of these

tion of suitable storage devices and reduction of gen- various types of storage devices and has also promoted feature issue: Smart Community erator capacities are important factors to consider so the joint development of storage devices. Lithium ion that the installation of equipment will be economical. capacitor modules for power converters are products Furthermore, as the scale of the system increases, that were jointly developed by Fuji Electric and FDK there will be a greater number of installed sites of re- Corporation. These lithium ion capacitor modules newable energy, and fl uctuations in the output of the can be used for nearly the same purposes as electric renewable energy will become more diffi cult to detect. double-layer capacitors and are smaller and lighter In such cases, fast frequency compensation for the sys- weight than electric double-layer capacitors of the tem, including demand fl uctuation, is effective. same capacitance. The external appearance of a lithium ion capacitor 3.4 Selection of storage devices When confi guring a microgrid, the selection of storage devices is important in terms of both operation and economic effi ciency. Fuji Electric, with the help of storage device manufacturers, has conducted validation testing of nickel metal hydride batteries, high-cycle lead-acid storage batteries and electric double-layer capacitors at the Nishime Wind Farm. As a result of this validation testing, Fuji Electric has developed a storage device management function that considers the allowable depth of discharge and cycle life characteristics for each device. The different types of storage devices have different characteristics as shown in Fig. 4. The selection of storage devices must consider, in addition to these

1,000

Lithium ion Fig.5 Appearance of lithium ion capacitor module battery

100 Lithium ion capacitor Table 2 Speciﬁ cations of lithium ion capacitor module

Lead-acid Item Speciﬁ cations storage Rated power DC45 V (27 to 45 V) 10 battery Initial static 200 F or higher (for 1 A discharge) Electric capacitance double-layer Initial internal DC capacitor 19 mΩ or less (for 100 A discharge)

Volumetric energy density (Wh/L) resistance 1 Charge and discharge 10 100 1,000 10,000 100,000 20 A current (rated) Volumetric power density (W/L) External dimensions W203×D134×H193 (mm) Fig.4 Storage device type and performance Mass 6 kg

Microgrid System for Isolated Islands 127 is shown in Fig. 5, and its specifi cations are listed in frequency-following performance of approximately 30 Table 2. ms for frequency fl uctuations in an actual power system, and has applied this fast-frequency detector to 3.5 Fast frequency detector fast-frequency fl uctuation compensation as part of the Frequency detection in the microgrid provides not microgrid control function. Fig. 6 shows an example of only an indicator of the power quality, but is also an actual measurement results obtained with the newly important indicator for assessing the balance between developed fast-frequency detector. the supply and demand of power within a microgrid that includes internal combustion generators. 4. Demonstration tests of Isolated Island In order to achieve coordinated control over the Microgrid System entirety of an independent power system on an isolated island, the microgrid control must function effectively 4.1 Demonstration tests in small-scale isolated island in response to instantaneous frequency fl uctuations system that pre-existing control devices are unable to follow. Fuji Electric has delivered isolated island mi- The principle of system frequency detection is crogrid-related equipment to the Kyushu Electric Pow- based on, for example, the number of times that the er Co., which has received an “Island Independent-type system AC voltage transitions from a negative voltage New Energy Demonstration Project Grant” from the to a positive voltage within a certain period of time, Japanese Ministry of Economy, Trade and Industry. A and a method(1) for computing the time of an AC cycle summary of the equipment installed is listed in Table from the time required for N transitions, or the like is 3. used. In this case, the frequency detection requires a The amount of new energy adopted in relation to detection time ranging from several hundred millisec- the scale of the system varies by approximately 10 to onds to ten seconds. 30% depending on the island, but exceeds 50% of the Using the system AC voltage as a signal source, minimum demand occurring during an intermediate and a proprietary error compression algorithm and an optimized characteristics fi lter, Fuji Electric has developed a fast-frequency detector that achieves a

60.3

60.2

60.1

60.0 Actual measured results 59.9 Frequency (Hz) 59.8 Actual frequency

59.7 −2 −1012345678 Cycle (1 cycle=16.667ms)

Fig.6 Example measurement results of fast frequency detector Fig.7 Appearance of storage containers

Table 3 Overview of equipment to be installed (small-scale isolated island system)

Equipment to be Lithium installed Solar Wind Lead-acid ion power power batteries batteries Name of (kW) (kW) (kWh) isolated (kWh) island Kuroshima 6.0 10 256 66 Takeshima 7.5 ̶̶33 Nakanoshima 15.0 ̶ 80 ̶ Suwanosejima 10.0 ̶ 80 ̶ Kodakarajima 7.5 ̶ 80 ̶ Takarajima 10.0 80 ̶ ̶ Fig.8 Overall view of system (Kuroshima)

128 Vol. 57 No. 4 FUJI ELECTRIC REVIEW Table 4 Overview of equipment to be installed (medium-scale isolated island system) microgrid-related equipment to the Okinawa Electric Power Co., which has received an “Island Independent- Equipment Electrical power storage system type New Energy Demonstration Project Grant” from to be installed Solar power Converter Capacitor the Japanese Ministry of Economy, Trade and Indus- (kW) capacity capacity try. A summary of the equipment installed is listed in Name of (kW) (kWh) isolated island Table 4. Taramajima 250 (25) 300 7.2 In this system, the abovementioned lithium ion capacitor module was applied to system stabilization Yonagunijima 150 (15) 200 4.7 for the fi rst time in the world. Capacitors for each Kitadaitoujima 100 (10) 100 2.9 type of equipment were designed so as to be able to Note: Values enclosed in parentheses show the capacity of Fuji Electric’s smooth the steep output fl uctuations occurring in the fi lm-type amorphous solar cell “FWAVE” system within the response range of pre-existing control equipment. Additionally, the control apparatus employs fast-frequency control that utilizes a fast- frequency detector, and for fl uctuations in the system frequency, is provided with a function that aims to stabilize the frequency prior to the response of the gov-

ernor-free function of a pre-existing power generating feature issue: Smart Community system. Fig. 9 shows an overall view of the installed system.

5. Postscript

This paper has introduced Fuji Electric’s charac- teristic products and application technology for isolated island microgrids. In the future, with system standardization and the completion of packaging, Fig.9 Overall view of system (Taramajima) Fuji Electric plans to pursue economic efﬁ ciency, and streamlined transportation and execution with an eye period such as the Spring or Autumn. Storage cells, on overseas markets. consisting of high-cycle life lead-acid storage batteries Finally, the authors wish to thank all the relevant and lithium ion batters, are used for ﬂ uctuation com- individuals from the Kyushu Electric Power Co., Oki- pensation, peak shifting and other smoothing purpos- nawa Power Co., and Okinawa Enetech Co. for their es. Because these islands are far from the mainland tremendous cooperation and guidance regarding the and the transport constraints are severe, electrical adoption of equipment for the demonstration projects products such as interconnecting equipment and in- and their cooperation in providing materials for this verters are all installed and wired in small storage con- manuscript. tainers on the mainland, and are then shipped in order to streamline the onsite construction work. References Figure 7 shows the external appearance of storage (1) IEEE 61000-4-30 Electromagnetic compatibility (EMC) containers and Fig. 8 shows the overall view of the sys- – Part 4-30: Testing and measurement techniques – tem. Power quality measurement methods. p.25.

4.2 Demonstration tests in medium-scale isolated island system Fuji Electric has also delivered isolated island

Microgrid System for Isolated Islands 129 Cooperative University-Industry Research with Zhejiang University: Toward the Creation of Smart Grid Related Business Yun Lei † Kimihisa Kaneko † Naoto Kobayashi †

ABSTRACT

In China, the economy has continued to grow and the market has continued to expand since the year 2000. To develop and produce products that meet the needs of customers in China, Fuji Electric has established cooperative relationships with several Chinese universities and is engaged in cooperative research in university-industry partnerships. Specifi cally, Fuji Electric and Zhejiang University have entered into a comprehensive agreement and are advancing a unique partnership that aims to advance research work for the creation of new products and new business and also to promote activities that will contribute positively to society. Building upon the prior development work and fi eld testing of systems that comply with GB standards (Chinese national standards) for power quality measurement in a distribution system, this collaboration will endeavor to expand smart grid related business to the fi eld of power stabilization technology.

1. Introduction (e) Active business management and university- industry collaboration In the 1990s, as a result of China’s policies of re- There is an active exchange of personnel between form and opening-up, many foreign companies decided universities and governments/administrative authori- to move into China. With the launching of a new base ties. As a result, networks closely connected with for motor manufacturing, Fuji Electric also began to industry, government, academia and research institu- move into China. tions are formed and have a signifi cant impact on gov- In the 2000s, market in China has expanded as ernment policy. its economy has developed, and in preparation for the All university students live in dormitories, and this 2008 Beijing Olympics, infrastructure development has student lifestyle fosters a strong sense of camaraderie been advanced at a rapid pace. Under these circum- that continues even after graduation. Eighty-four stances, in order for foreign companies in China to ex- percent of graduates fi nd jobs with private companies, pand their business into the Chinese market, not just and corporate ties using “old boy” networks are utilized low cost manufacturing, but also product development extensively. Also, 14% of graduates fi nd jobs in the and manufacturing suited to the needs of Chinese cus- government sector, further strengthening the ties be- tomers have come to be strongly required. In response, tween one’s alma mater and industry, government and Fuji Electric is establishing cooperative relationships academia. with many Chinese universities, and has entered into Thirty-fi ve percent of corporate research and de- a comprehensive partnership with Zhejiang Universi- velopment expenditures in China in 2008 were out- ty. This paper introduces the university-industry part- sourced to universities, a high percentage that is ap- nership between Fuji Electric and Zhejiang University, proximately 12 times greater than that of Japan, and and efforts to create business opportunities relating to is an indication of the active collaborations between smart grids. industry and academia . The research outsourced from companies is performed mostly by graduate students 2. Characteristics of Universities in China under the guidance of professors. The number of these graduate students is about 13 times that of Japanese Owing to their political, national, cultural and universities . historical backgrounds, universities in China have the Many examples exist of universities themselves following characteristics. managing companies , and there is a strong entrepre- (a) Close relationship with government neurial mindset. The total revenue obtained from (b) “Old boy” network cultivated through dormitory corporate management by the top 20 Chinese universi- life ties in 2009 was 120 billion yuan (approximately 1.48 (c) Contributor to Chinese company research trillion yen). (d) Research and development supported by an In this way, Chinese universities exert a much abundance of graduate students greater infl uence on domestic industry than Japanese universities. † Fuji Electric Co., Ltd

130 3. University-Industry Partnership With Zhejiang Systems Research and Development Center ” for a pe- University riod of 4 years, beginning in April 2006. At this Center, more than 10 research projects In Japan, some companies also utilize research were initiated in electrical and other fi elds, and re- at Chinese universities as one part of their research search and development as well as demonstration and development base (1) . These university-industry experiments were carried out, resulting in patent ap- partnerships, in addition to being an effi cient use of plications, published papers, and so on. research and development funds, are also reported One activity of this Center is to foster personnel to be advantageous for forming networking contacts, exchanges and educational cooperation, and techni- acquiring expertise in areas of academic research, and cal exchange meetings were held for specifi c technical so on. On the other hand, the need to manage intel- fi elds, such as power electronics, to promote mutual lectual property carefully and to pay close attention to understanding in academia and industry. Addition- compliance with the laws of Japan and China has also ally, Zhejiang University professors also held educa- been reported. tional activities for employees of Fuji Electric’s base in Fuji Electric, having fully analyzed and considered China , and the collaboration was expanded to include such advantages and disadvantages in conjunction technical exchanges with relevant affi liates. The di- with its relevant departments and affi liates, is devel- verse range of activities over these 4 years resulted in

oping university-industry partnerships as part of its a closer partnership and greater mutual trust by both feature issue: Smart Community business expansion in China. sides. In 2004, Fuji Electric entered into a university- industry partnership with Zhejiang University, and 3.3 Zhejiang University – Fuji Electric Innovation Center began research and development work. Then, in April Based on the mutual trust cultivated with Zheji- 2006, Fuji Electric and Zhejiang University entered ang University, and in consideration of the benefi ts of into a comprehensive collaborative agreement, estab- cooperation in a wider range of fi elds and the need for lishing the “Zhejiang University – Fuji Electric Sys- activities that emphasize new business creation in ad- tems Research and Development Center” at Zhejiang dition to new product development, Fuji Electric has University, and expanding their university-industry decided to adopt a collective approach as entire group. collaboration over many fi elds. Building upon the posi- Accordingly, in April 2010, Zhejiang University and tive results obtained from specifi c activities over four Fuji Electric Holdings Co., Ltd. established the “Zhe- years, and in order to strengthen cooperation for the jiang University – Fuji Electric Innovation Center” in creation of additional business, Fuji Electric founded the Zhejiang University campus. the “Zhejiang University – Fuji Electric Innovation Global warming and climate change are becom- Center” in April 2010 to enlarge the scope of collabora- ing serious problems at the global level and in order tion and to promote various collaborative activities.

3.1 Individual research Fuji Electric and Zhejiang University have maintained a certain relationship at the researcher level since the 1990s. To further expand business in China, in 2004, Fuji Electric conducted a feasibility study in the power supply ﬁ eld. Transportation Environment

3.2 Zhejiang University – Fuji Electric Systems Research and Development Center Energy Research and development, In the research and development of basic and ap- Business creation plied technologies in China , in addition to conducting Technology exchanges, individual research in specifi c technical fi elds as in Utilization of intellectual property the past, from the medium and long-term perspective, Personnel exchanges, there is a need for collaborative activities and close co- Educational cooperation operation in many technical fi elds in order to advance Contribution to society research. For this purpose, Fuji Electric Systems Co., Ltd.*1 , the principal operating company of the collaborative research project with Zhejiang University , established and operated the “ Zhejiang – Fuji Electric

*1: Fuji Electric Systems Co., Ltd.: Merged with Fuji Elec- tric Holdings Co., Ltd. in April 2011 to create the present Fuji Electric Co., Ltd. Fig.1 Key business areas and activities

Cooperative University-Industry Research with Zhejiang University: Toward the Creation of Smart Grid Related Business 131 to contribute to solving these problems Fuji Electric were carried out, and at present, smart grid-related is focusing on the “energy and environment” business business creation is being expanded. Table 2 lists fi eld, and intends to expand businesses globally in this items implemented in the power system fi eld, and defi eld. For this purpose, the technology and human re- tails are presented below. sources of Zhejiang University and the technology and business experience of Fuji Electric are leveraged to 4.1 Chinese power system business feasibility study strengthen business creation activities primarily in the From 2004 to 2005, Fuji Electric conducted a feasi- “energy and environment” fi eld. bility study of the power system business in China. Efforts at the Center, mainly in the three busi- With its rapid economic growth, the demand for ness fi elds of energy, environment and transportation, power in China increases day by day. As the capacities are concentrated on the four activity areas of research of large-scale power facilities are increased, improve- and development and business creation, technologi- ments in power transmission and distribution systems cal exchanges and utilization of intellectual property, are also expected. Having acquired power system de- personnel exchanges and educational cooperation, and velopment and automation experience during periods partner cultivation and societal contributions (see Fig. of high growth in Japan, Fuji Electric’s power system 1). monitoring and control technology is considered to be essential for China. To expand Fuji Electric’s busi- 4. Initiatives in smart grid-related fi elds ness opportunities in the electric power fi eld in China, the fi rst step was to conduct a feasibility study of the In the fi eld of power systems, one of the fi elds in power system business in China. the energy business sector, university-industry part- Fuji Electric’s proprietary technology was analyzed nerships are expanding through a three-tier frame and studied with regard to its applicability and busi- work (see Table 1), whereby a feasibility study of the ness potential in the Chinese market in the following power system business in China was conducted fi rst, seven areas: energy management systems (EMS), dis- then product development and demonstration projects tribution management systems (DMS), automatic meter reading (AMR), power quality (PQ) measurement Table 1 Framework of university-industry partnerships and countermeasures, energy conservation, new en- 2004 2006 2010 ergy, and electricity trading market. The results indi- Organization to to to cated that, in the near future, power infrastructure in 2005 2009 2013 China will require DMS effective for reducing the an- Chinese Individual power supply nual downtime and increasing the effi ciency of power research business fea- distribution equipment investment, PQ measurement sibility study and countermeasures effective for assessing the power Zhejiang Product quality, i.e., high frequency harmonics, instantaneous University – Fuji develop- voltage drops and the like, and EMS and AMR effec- Electric Systems ment and Research and demon- tive for increasing the effi ciency of supply-demand bal- Development stration ance control, including energy conservation. Center projects Fuji Electric has identifi ed the following three Zhejiang Smart grid- areas as high-priority technical fi elds, and is moving University – related busi- Fuji Electric ahead with research and development for the Chinese ness creation Innovation Center

Table 2 Implemented items in the electric power system ﬁ eld

Power-related cooperation phase Items implemented Achievement Identifi cation of 3 high-priority technical fi elds Chinese power system business Of the technology owned by Fuji Electric, adaptabil- (a) DMS fi eld feasibility study ity in the Chinese market was analyzed for 7 fi elds (b) PQ fi eld (c) EMS fi eld Development in the identifi ed fi elds: ™Localization of distribution automation system ™ Acquisition of certifi cation for wide- ™Field trial of wide-area PQ* measurement sys- Product development and demonstration area PQ* measurement system tem, Development of complex PQ* countermea- projects ™ Practical application at power utilities sure devices ™Development and application of system-wide VQ* control algorithms ™Demonstration of smart grids Smart grid-related business creation ™Development of system-related simulation mod- ™ Business creation els, etc.

* PQ：Power Quality * VQ：Voltage Q（reactive power）

132 Vol. 57 No. 4 FUJI ELECTRIC REVIEW market. of power systems in China have come to be understood. (a) DMS fi eld In addition, by carrying out demonstration trials at (b) PQ fi eld power companies, the adaptability of Fuji Electric’s (c) EMS fi eld proprietary technology to the Chinese market was confi rmed. The results of these activities led to the acqui- 4.2 Product development and demonstration projects sition of certifi cation of a wide-area PQ measurement From 2006 to 2009, at the Zhejiang University – system, which directly tied to business opportunities. Fuji Electric Systems Research and Development Cen- ter, product development and demonstration experi- 4.3 Creation of smart grid-related business ments were carried out for the three technical fi elds From 2010 to 2013, the Zhejiang University – Fuji identifi ed in the feasibility study. Electric Innovation Center is endeavoring to create In the DMS fi eld, the many proven DMS solutions smart grid-related business opportunities. of Japanese power companies were additionally devel- Since the global fi nancial crisis, in order to pre- oped and localized so that the capability to interface vent global warming and as economic policy, smart with other systems, the accident recovery sequence grids have attracted attention as a way for realizing and so on would accommodate the operational manage- more effi cient power systems and to help popularize ment rules and structure of Chinese power companies. new type of energy. Several national key projects (Na-

In the PQ fi eld, power measurement terminals tional High-tech Research and Development Programs) feature issue: Smart Community that comply with GB standards (Chinese national have been conducted at Zhejiang University so far. standards) were developed, and fi eld trials of a wide- Especially noteworthy is the recent involvement in a area PQ measurement system (Fig. 2) that uses an national key project for conducting demonstrations actual power company system and its information in- related to smart grid usage on remote islands. Based frastructure were carried out . Typical problems with on established power system monitoring control tech- the power quality in China were analyzed and power nology and a business infrastructure, Fuji Electric is electronics devices were researched and prototypes endeavoring to create new smart grid-related business were developed in order to realize complex PQ coun- that will fully utilize power electronics, an area of tech- termeasures. Additionally, system-wide VQ (Voltage nical strength of Fuji Electric. Q (reactive power)) control algorithms were developed This Center is advancing smart grid demonstra- to control voltage and reactive power throughout the tion projects, including the development of new energy entire system, including the power transmission and system interconnection simulation models and the lo- distribution system, and a certain power company has calization of power system stabilization technology, applied these algorithms. for systems that strive to achieve a renewable energy In the EMS fi eld, electric power load prediction system that combines safe, reliable energy with envi- and how to control limited power supply facilities so ronmental technologies and a self-suffi cient balance as to best accommodate load fl uctuations are major system. challenges. Fuji Electric has researched and analyzed various load leveling control methods, such as the use 5. Postscript of power pumped-storage power generation and chiller cooling systems to shift power utilization to low-load Energy policy is being reviewed as a consequence (nighttime) hours. of the Great East Japan Earthquake of March 11, Through such specifi c research and development 2011. As renewable energies such as solar and wind activities, the characteristics and technical challenges power become widespread, and load leveling by storing electric power and power system stabilization is needed increasingly, those trends will expand globally, Factory A Supermarket and such needs will increase further in China as well. ** Fuji Electric, based on its wealth of accumulated tech- Research Factory A Factory B ***center nology, intends to create smart grid related business opportunities in China in order to contribute to eco- Ethernet VPN Customer nomic development and to help resolve environmental Gateway problems in China. ****

Factory C Power utility Office 2 Office 3 ** References Server Server (1) Jianmin Jin. Japanese Enterprises and R&D Activities Hotel Office 1 1 2 * Measurement point by Multinational Enterprises in China. Fujitsu Re- search Institute. Reserch Report. No. 270, July 2006. Fig.2 Overview of wide-area PQ measurement system

Cooperative University-Industry Research with Zhejiang University: Toward the Creation of Smart Grid Related Business 133 System Technology that Supports Next Generation Electricity Delivery Satoru Takahashi † Yasuhisa Kanazawa † Tatsuo Suzuki †

ABSTRACT

When a large amount of solar power is introduced into a system, reverse ﬂ ow and voltage ﬂ uctuations occur. Moreover, this is feared to affect the demand/supply control, since net demand cannot be ascertained. To solve this problem, Fuji Electric optimized the placement and setting values of voltage control equipment, and is developing a centralized control method. Devices models for analysis, a method of predicting solar power output and a demand/ supply control function are also being developed. To replace aging facilities, a unit replacement-type protective relay using a new IED (Intelligent Electrical De- vice), and in support of the diversifying operating modes of power companies, IP network devices, middleware for wide-area distributed power, and a disaster prevention and crisis management system are being developed.

1. Introduction has developed and delivered in the power distribution fi eld. As power consumption increases due to continued Challenges related to the mass adoption of distrib- economic growth, power companies and manufacturers uted power generation, as well as challenges involved have been endeavoring for many years to realize a sta- in the renewal of aging equipment and efforts to in- ble supply of power, which is the primary goal of power crease the operating effi ciency are described below. distribution, and to streamline their operations with the aim of increasing economic effi ciency. Systems 2.1 Challenges relating to mass adoption of distributed that support power distribution include centralized power generation monitoring control systems that use computer technol- (1) Challenges of power distribution systems ogy, protection and control systems that prevent the In the mass adoption of distributed power sources, spread of system faults in the event of system trouble, such as in the case of solar power generation, the and so on, and these systems have been utilized to re- occurrence of voltage rises due to reverse fl ow and alize a high degree of supply reliability. voltage fl uctuations on the distribution line due to In the future, with the aim of achieving a low- abrupt output fl uctuations are problems associated carbon society, the mass adoption of distributed power with power distribution systems. At present, power generation predominately consisting of solar power generation and wind power generation is anticipated.

Additionally, there will be a need for the renewal of Operating system Demand Power system Simulators Distribution aging protective relay equipment that had been deliv- for dams estimation system control system automation system ered more than 20 years prior and for increasing the efﬁ ciency of power system operation. These types of challenges and Fuji Electric’s efforts in the power distribution ﬁ eld are described below. Dam control center Central load dispatching center

Local load dispatching center 2. The Power Distribution Field: Present Status Thermal and Challenges power plant Control center Service office Hydro power plant In the power distribution ﬁ eld, Fuji Electric has Substation for power Distribution Utility developed and delivered various types of support sys- system interconnection substation customers Nuclear power plant Commercial-scale utility customers tems, including power system control systems, distri- Monitoring control system Remote supervisory Digital relay Equipment bution automation systems, remote supervisory control for electric power plant control system monitoring system system, protection and control systems, system analysis simulators and power demand prediction systems. Figure 1 shows the main products that Fuji Electric

† Fuji Electric Co., Ltd Fig.1 Fuji Electric’s power distribution products

134 regulating devices such as on-load tap-changing trans- mode is needed. formers (LRT: load ratio control transformers), auto- Moreover, the workload on the operator increases matic voltage regulators (SVR: step voltage regulators) as monitoring and control is performed over a wider and static reactive power compensators (SVC: static range, and remedial measures are needed. var compensators) are used at distribution substations with the aim of realizing a suitable system voltage in 3. Fuji Electric’s Efforts in the Next-Generation a power distribution system. However, the regulating Power Distribution Field ability of a voltage control method based on the effect of individual voltage regulating equipment is limited, 3.1 Measurers for the mass adoption of distributed power and solutions for anticipated problems are needed. source s (2) Challenges in supply/demand operational man- (1) Measures for distribution systems agement (a) Power distribution system voltage ﬂ uctuation In the case of the mass adoption of solar power suppression technology generation in homes, the generated power output will As voltage ﬂ uctuation suppression technology not be measurable in real-time. The power compa- for next-generation power distribution systems that nies will be unable to ascertain the net demand for support the mass adoption of distributed power power, and therefore must, in order to maintain the sources, Fuji Electric is using state estimation, pow-

power system frequency, implement supply/demand er fl ow calculations and optimization methods to de- feature issue: Smart Community operational management based on predictions of solar velop planning support for optimally arranging volt- power generation output. Moreover, to accommodate age regulating devices, and a voltage control method the absorption of surplus electricity at the load side for controlling the voltage in distribution systems to and increased loads due to sudden fl uctuations in the suitable levels. Fig. 2 shows an overview of the dis- weather, a storage cell optimization control function, a tributed voltage control developed by Fuji Electric. reverse fl ow detection function and the like are neces- (i) Optimal arrangement of voltage regulating sary. devices (3) Challenges in power system analysis To streamline the operation to plan for in- In the future, to demonstrate the effect of the installation or relocation, optimization techniques stallation of newly-developed distributed power sourc- are used to calculate the SVR installation loca- e s and the effect of control systems on the power sys- tion at which the deviation rate from upper and tem, analytical models for distributed power source s lower voltage limits is smallest throughout the must be designed to be easily and rapidly introducible year. into a systems analysis simulator. (ii) Optimization of voltage regulating device set points 2.2 Next-generation support of aging protective relay In order to minimize the operating fre- equipment quency of the SVRs, optimization techniques are Due to the aging of equipment and an accelerated used to calculate the combination of set points replacement cycle for major equipment components, for multiple SVRs at which the deviation rate renewal work for protection and control systems in from upper and lower voltage limits is smallest Japan will increase in the future. Protective relays throughout the year. utilize electronic components having a short improvement or elimination cycle, and device confi gurations that allow for easy updating by unit replacement are Distribution automation Offline distribution system the mainstream. Moreover, so that protection and system (online) control systems can be connected easily to equipment System status acquisition System status acquisition (power flow calculation, made by different manufacturers, i.e., so as to realize (power flow calculation, status estimation) status estimation) a multivendor system, monitoring control systems and Calculation of optimal set Optimal control calculation protective relay systems will converge further, aiming (optimization technique) points (optimization technique) for an all digital system. Set and control of voltage control device when needed Optimal location design

2.3 Improvement of operating effi ciency In order to reduce the operational management SVR cost of power systems, the trend toward consolidation LRT of multiple operational management organizations Pole transformer SVC Low High Low Low such as load dispatching offi ces and service offi ces voltage voltage voltage voltage load load load Photovoltaic load Photovoltaic provided with distribution automation systems has energy energy generation generation been accelerating in recent years. For this purpose, : Switch with sensor construction technology for monitoring and control systems capable of responding to changes in the operating Fig.2 Overview of distribution voltage control

System Technology that Supports Next Generation Electricity Delivery 135 (iii) Centralized control of voltage regulating de- companies. Using this technology, meteorological vices forecast information such as the amount of solar radia- So that the voltage throughout an entire tion is used to predict and estimate the effect on solar distribution bank incorporating large quantities power generation, and research is being carried out to of solar power generation remains within an ap- reﬂ ect those results in system-wide demand estimates. propriate voltage range, based on measurement Fig. 4 shows an overview of a demand estimate sys- information from switches with sensors, tap tem for solar power generation. The amount of solar values for load ratio control transformers (LRTs) power generation at certain locations is estimated by and SVRs on a distribution system, and optimal calculating the amount of solar radiation from numeric static var compensator (SVC) voltage command cloud cover data based on Grid Point Value ( GPV ) values are calculated, and are centrally con- forecasts by the Japanese Meteorological Agency, and trolled in real-time. in consideration of longitude-latitude information and (b) Next-generation optimizing control technique temperature forecasts. Fuji Electric plans to apply this demonstration project for power transmission and distribution systems To establish voltage ﬂ uctuation suppression technology, Fuji Electric is participating in the Historical demand

“Next-generation optimizing control technique Weather information Demand forecasting Power demand demonstration project” sponsored by the Japanese ™Max. temperature engine using neural Ministry of Economy, Trade and Industry. Aiming ™Min. temperature network technology ™Weather for the mass adoption of renewable energy such as etc. Time solar generation by 2020, this project will conduct, (a) Conventional demand forecasting with twenty-eight participating entities including Tokyo University, a three-year development and Historical demand Net demand curve demonstration experiment for an optimized control Apparent Weather information Demand forecasting demand method for demand-side devices, a system voltage ™Max. temperature engine using neural curve ™Min. temperature network technology

control method for distribution systems, and the like Power demand ™Weather in order to solve the problems shown in Fig. 3. Fuji etc. Electric is participating in the “voltage suppression Weather Predication of Prediction and estimation technology for distribution systems development” information amount of of amount of solar (GPV) solar radiation power generation sub-working group of the project. Time (2) Measures for a supply/demand operational man- (b) Demand forecasting at time of mass adoption of solar power generation agement using a demand forecasting system Fuji Electric has delivered power demand estimate Fig.4 Overview of demand prediction system in consideration systems that use neural network technology to power of solar power generation

2010 fiscal year 2011 fiscal year 2012 fiscal year

Interim report Interim report Final report

Issue (1) Development of voltage fluctuation Design of distribution Construction of distribution Overall demonstration suppression technology in power system model system model, project, summary distribution system Creation of control software

Issue (2) Development of low-loss, low cost Review and design of Fabrication, Installation in Demonstration test, device that applies next-generation control method, Factory test summary Development of Akagi test site device technology elemental technology

Issue (3) Fabrication, I/F design Testing Development of control technology Consumer unit demonstration Overall demonstration for demand-side devices according Consumer Fabrication

Subject of research tests, Construction of model tests, summary to the system status model design for simulation Issue (4) Design of central dispatching Construction of central dispatching

Overall demonstration Dissemination of result information Review the supply/demand planning, and upper-level system model, and upper-level system model, Review of evaluation scenario Fabrication of control software tests, summary II Demand-sidecontrol, System-side I and communications infrastructure for an entire system Review and evaluation of communication method and information between various power companies and consumers (Source: Next-generation optimizing control technique demonstration project for power transmission and distribution systems document)

Fig.3 Schedule of next-generation optimizing control technique demonstration project for power transmission and distribution systems

136 Vol. 57 No. 4 FUJI ELECTRIC REVIEW estimation technique to smart community demonstra- for power system device location and control, such as tion projects. studies of the operating method and point of optimum Additionally, in a remote island micro-grid dem- location of electric power storage systems installed on onstration project, Fuji Electric has developed and ap- a power distribution system, including assessment of plied a supply/demand operational management plan- the effect on power quality due to the mass adoption of ning function, an economic load allocating function and solar power generation and wind power generation. a load frequency control function. As the mass adop- Fuji Electric has begun development of a next-gen- tion of distributed-type power sources and the adoption eration hybrid-type power system analysis simulator of electric vehicles (EV) progresses, power companies that combines conventional analog technology with the are expected to implement supply/demand operational latest digital processing technology. management in smaller regional units than at present. For this purpose, Fuji Electric intends to apply 3.2 Next-generation substation protection and control its technical expertise acquired through demonstration systems projects to the power distribution ﬁ eld. At present, Fuji Electric is moving forward with (3) Measures for power system analysis the development of a new intelligent electrical device A power system analysis simulator is conﬁ gured (IED) that conforms to the IEC 61850 international from an equivalent reduced model of system compo- communication standards. While retaining the envi-

nent devices, and is used to analyze the power fl ow, ronmental performance, reliability, lifespan and the feature issue: Smart Community steady-state/dynamic-state stability, and power sys- like required of protective power-use relays in Ja- tem resonance phenomena, simultaneous faults, and pan, the new IED is positioned as a successor to Fuji the like. Electric’s existing protective relays and measurement Fuji Electric has delivered analog-type power sys- units, and is a highly reliable controller suitable for tem analysis simulators, capable of the real-time anal- use in protection, control, measurement and communi- ysis from surge phenomena of several micro seconds cation terminal applications. Fig. 5 shows an example to economic load allocating that lasts several hours confi guration of the new IED. The combination of a or more, primarily to power companies and universi- basic unit and an expansion unit allows the optimal ties. An analog-type power system analysis simulator confi guration to be provided for individual equipment performs calculations with continuous quantities, and application. Fuji Electric is also considering applica- therefore has an advantage in that the divergence oc- tion to all-digital substations in the future, including curring in digital calculations due to the operation application to protection and control systems. time interval and numeric solutions is less likely to Moreover, based on the assumption of modular occur. In recent years, to analyze the effect on a power replaceable units, Fuji Electric is also advancing the system of the adoption of large-scale renewable energy development of a main unit for digital relays. Fig. 6 generation from massive solar power stations, wind shows an example of unit replacement-type protec- stations and so on that is associated with output fl uc- tive relay. By integrating the main processing part, tuations, Fuji Electric has developed models of solar the input/output part and the power supply part of a power generation and wind power generation, and has supplied these as device models. Among such efforts, there is increased utilization Front view Future range of replacement Side view of

of analog-type power system analysis simulators in the 110 interior analysis of high-level application technology of future power systems, such as next-generation power distribution systems, smart communities and the like. Analog-type power system analysis simulators sup- unit port the research and development of future methods Computation

D/D 2,300 output unit Digital input/ Input converter,

A modular upgradable unit and detachable connector facilitate replacement

Basic unit and operation panel Expansion unit

Fig.5 Example conﬁ guration of new IED Fig.6 Example of unit-replacement type protective relay

System Technology that Supports Next Generation Electricity Delivery 137 protective relay into a single unit, the structure can be a single server is centrally positioned at one location upgraded simply by replacing each single unit. and clients only are installed at the other various locations. Other systems include a backup system for 3.3 Technology for realizing improved operational man- a server positioned among multiple locations, and a agement system capable of monitoring the respective systems at Fuji Electric has been providing technologies that adjacent locations. support the realization of operational management To realize these confi gurations, the distributed systems confi gured in various forms, such as for ensur- servers must be constantly monitored for application ing the reliability of information transmission. These startup/response, database high-speed equivalence, technologies are outlined below. and server status, and for this purpose, Fuji Electric (1) IP network support uses middleware for wide-area distributed power sys- In the case where multiple operational manage- tems. ment organizations are to be consolidated, ensuring a This middleware has been realized by extending route for the transmission of information to a substa- the conventional middleware for power systems to tion and guaranteeing the reliability of that transmis- wide-area distributed power systems. Thus, the exten- sion of information are challenges. Fuji Electric ap- sion of an existing in-use system to a wide-area system plies the JEMA industrial protocol known as protocol involves little risk of the need for signifi cant software for mission critical industrial network use (PMCN) modifi cations and the installation of new applications. to ensure data ordering and real-time performance, (3) Support for disaster crisis management and to provide an IP network terminal that supports When operational management organizations are 2-route transmission and 1:N transmission. While merged, the operator burden increases not only for maintaining a conventional level of reliability, these usual business operations, but also in the response to terminals support the different operating systems of natural disasters such as earthquakes, typhoons and various power companies. so on. Consequently, Fuji Electric has developed a “Di- (2) Middleware for wide-area distributed power sys- saster crisis management support system.” This systems tem provides an integrated display, which shows load The different power companies have various sys- dispatching information, map information, weather tem confi gurations. Fig. 7 shows an example confi gura- forecast information and disaster prevention information of a wide-area distributed system. In this system, tion for each layer, and makes a preliminary estimate of risk based on the weather forecast and disaster prevention information, and supports operations to avoid

Service office A that risk. If a real disaster were to occur, the system Monitoring control server will provide subsequent recovery support. Service office C Service office B 4. Postscript Service office A Data relaying Monitoring Gateway Application apparatus control server server Middleware In addition to systems for the power distribution ﬁ eld, Fuji Electric has also delivered many dam control Multiple systems systems, including pumped-storage power generation constructed independently Reliable high-speed equivalence within a single server of the system database stations, water control systems, gas control systems, via wide-area network and so on. As the range of operation expands from microgrids to smart communities, which aim to increase efﬁ ciency and optimally operate all forms of energy, including Service office B Service office C electricity, heat and water, Fuji Electric, based upon

Monitoring control servers and other servers are concentrated in its prior experience with social infrastructure, intends the Service office A, and only client terminals are installed at other service offices to contribute to stabilizing the supply of electric power and to improving the efﬁ ciency of its usage. Fig.7 Example conﬁ guration of wide-area distributed system

138 Vol. 57 No. 4 FUJI ELECTRIC REVIEW Power Electronics Technology that Supports Smart Grid Shinsuke Nii † Masaki Kato †

ABSTRACT

A smart grid is a system that reduces the effect that the mass adoption of renewable energy has on the total power system. Because the generated power output from renewable energy is generally difﬁ cult to control, a power supply system capable of implementing high-speed and high-accuracy control is needed for the mass adoption of renewable energy in the system. Power electronics technology plays an important role in realizing such control. The main power electronics applied technologies are charging/discharging control technology and demand/supply control technology. Devices suitable for use in a smart grid include power electronics devices for power distribution, smart PCS and new energy packages, and the deployment of these devices to the “ Fuji Smart Network System” is targeted.

feature issue: Smart Community

1. Introduction as well as a function for safely interconnecting with a power system. This section describes the require- The adoption of renewable energy is being promot- ments and technical trends of recent power electronics ed as a measure to help mitigate the problem of global devices. warming. The generated power output from renewable energy, however, is often diffi cult to control, and 2.1 Functions and technical trends of power system inter- if adopted in large quantities, may cause frequency connection fl uctuations throughout the entire power system and (1) Low voltage ride through (LVRT) local voltage fl uctuations may occur. A smart grid is As an example of a function necessary for power a system that reduces the effect on the entire power supply interconnection, the LVRT function is described system from the mass adoption of renewable energy, below. LVRT is a function that enables a device to con- and ensures a stable supply of electrical power. By tinue outputting without parallel off*1, even when the simultaneously controlling the generation, distribution system voltage drops. In the case where only a small and consumption of energy, the effi cient use of energy amount of renewable energy is introduced into a power can be achieved. With a smart grid, a compensating system, even if a distributed power source disconnects high-speed high-accuracy power supply system must due to a drop in the system voltage, the effect on the be used to connect renewable energy, for which the overall system will be minor and non-problematic. In generated output power is diffi cult to control, to the the case where a large amount of renewable energy is power system, and power electronics technology plays introduced into a power system, however, if the dis- an important role in the realization of such a system. tributed power sources disconnect from the power sys- In particular, many types of distributed power sources tem all at once, an imbalance will occur between the generate DC power, and power electronics technology amount of power generation and the amount of load, for performing power conversion is one of the most im- and the frequency stability of the system will decrease portant technologies for smart grids. as a result. If the amount of simultaneous parallel off This paper discusses the role, functions and de- is large, then in order to maintain the power supply vices of power electronics required in smart grids, and frequency, the load must be dropped. Accordingly, the also describes application examples and initiatives for following three characteristics are sought in order to the future. connect distributed power sources to a power system. (a) To accommodate frequency changes 2. Trends in Power Electronics Devices for (b) To connect to the power system and supply pow- Smart Grids er to the extent possible, even when the voltage drops The power electronics devices used in smart grids (c) To connect to the power system and supply are required to have a function that is capable of ac- power as soon as the system voltage is restored commodating fl uctuations in frequency or voltage, *1: Parallel off: Disconnection of electric power generating † Fuji Electric Co., Ltd. equipment or the like from a power system

139 following a parallel off power storage device is used to implement this func- (2) Isolated operation detection function tion, and depending on the period of fl uctuation, the An isolated operation detection function is essen- power storage method may need to be changed to stor- tial for connecting to a power system. Isolated opera- age cells, lithium ion batteries, electric double-layer cation is the state in which an isolated system that has pacitors, and the like, and appropriate discharge con- been disconnected from the power system is supplied trol technology for the storage method is also needed. with electricity from the output of a distributed power If the fl uctuation in renewable energy power source only. In the isolated operating state, there is generation is to be adjusted with individual power the possibility of electric shock or equipment damage, stabilizers, then the same number of stabilizers as and this state must be detected as soon as possible and power generators (or power plants) will be needed. In the relevant distributed power sources must be discon- contrast, an area-type stabilizer allows the fl uctuation nected. (See explanation on page 152). to be averaged to that the total equipment capacity can The method used to detect isolated operation is be reduced, and is more economically effi cient than the either passive or active. The passive method detects individual approach. This area-type stabilizer controls sudden changes in voltage phase, frequency and the the amount of power generation, including the amount like resulting from imbalances between the generated of renewable energy, over a wide area (such as a town, output power and the load during the transition to city, prefecture or larger). For this purpose, the capac- isolated operation, while the active method continu- ity of the stabilizer must be increased by expanding ously applies voltage and frequency fl uctuations and the individual device capacity of the inverters used in utilizes the fact that the fl uctuations become noticeable power storage systems and arranging them in parallel during transition to isolated operation. Presently, in confi gurations. power distribution systems, the load is larger than the Additionally, in small-scale power systems at re- generated power, and therefore the passive method mote islands and the like, the generators have low operates reliably even when there is a transition to iso- inertia constant, and disturbances are likely to oc- lated operation. However, if the number of distributed cur when a supply-demand imbalance arises due to a power sources increases and the balance between the power fl uctuation. Such unstable states can be stabi- generated power and the load is realized within the lized with a power storage device, and for this purpose, power distribution system, then system fl uctuations high-speed and high-precision control are required of will be smaller when transferring to isolated opera- the inverter. tion, and detection of isolated operation based on the passive method may not be possible. In the past, the 3. Usage of Power Electronics in Smart Grids passive method had provided the main protection, and the active method had been used as a backup. How- Recently, power electronics products incorporating ever, because of the risk of being unable to detect iso- the above technologies have become possible to manu- lated operation with the passive method when a large facture, and the applicable range of power electronics number of distributed power sources are introduced, in technology has expanded. Additionally, complex con- recent years, the active method has been considered as trol has become easier to implement in the distribution the main protection. of energy, enabling more effi cient utilization of the At present, especially for small-scale photovoltaic public infrastructure. power generation, unifi cation toward an active method Figure 1 shows a conceptual diagram of a smart that is free of mutual interference is underway. Also, power distribution supply chain in a smart grid being the trend of isolated operation of medium and large promoted by Fuji Electric. In Fig. 1, sensors and smart capacity power conditioning systems*2 (PCS) must be meters monitor the system information, and power watched closely. generation, distribution and consumption are optimized so that the system will operate more effi ciently. 2.2 Function for accommodating power generation fl uc- Fuji Electric has experience with many such examples tuations and power system fl uctuations for this purpose. Of the power electronics technology In the past, generators have been controlled to that may be used in a smart grid, implementation ex- absorb load fl uctuations and to stabilize frequency. If amples involving power generation and distribution the amount of renewable energy generated fl uctuates, are introduced below. however, a balance between supply and demand is diffi cult to achieve with only generator control. For this 3.1 Usage of power electronics technology in power gen- purpose, the output at the renewable energy side must eration be adjusted to minimize the effect on the system. A The power stabilizer is introduced below as an example application of power electronics for power gen- *2: Power conditioning system: Device for converting gener- eration. ated electric power from a photovoltaic cell, storage cell The generators in a power system are mainly or the like into system power . rotary-type generators, and this is essentially the same

140 Vol. 57 No. 4 FUJI ELECTRIC REVIEW Large-scale centralized power plant Energy generation (supply) (hydropower, thermal power, nuclear power)

Renewable energy Microgrids Hydropower Nuclear Fuel cells power Mega-solar plants and Regional energy Transmission wind farms and microgrids Thermal power systems

Substations Distribution

Distribution systems System control devices (6.6 kV, 200/100 V) Distribution automation Protective relays, IEDs Sensors

Power storage facilities feature issue: Smart Community

Consumer (demand)

Smart meters Smart factories Energy-saving devices Green IDC Energy-saving systems

Consumer Smart meters Smart meters

Fig.1 Conceptual view of a smart power distribution supply chain for smart grids as well. As described above, however, when generating equipment that uses renewable en- 6.6 kV power system ergy is introduced in large amounts to a power system, Output of combined the frequency control of the system will be affected due interconnection points to the instability of the power generation. By using Wind power generation output Power stabilizer a power storage device to compensate for the power output generation instability and by implementing control so that the output of the generating equipment is stable, Rechargeable Power battery charge/ stable power can be supplied to the system. Figure 2 generation discharge Power status command shows the confi guration of this power stabilizer. Figure stabilizer Inverter control unit 2 shows the case of wind power generation, but the Wind power System generation controller same confi guration could also be used for photovoltaic output power generation. Power stabilizers charge and discharge storage cells so as to compensate for the corresponding output fl uctuation of renewable energy, thereby smoothing the Electric double-layer capacitor Nishime Wind Farm Rechargeable battery combined outputs at points of interconnection with the power system. Charging and discharging can be performed according to bidirectional inverter control. Fig.2 Overview of power stabilizer The purpose of smoothing is to stabilize the power system voltage and frequency. To stabilize the volt- capacity is desired. age, active power control and reactive power control Fuji Electric has installed this power stabilizer are performed. To stabilize the frequency, governor- at the Nishime Wind Farm which is operated by free (GF) control for short-duration fl uctuations, load Win-power Co., Ltd., an affi liated company, and has frequency control (LFC) for long-duration fl uctuations, conducted an experimental study. The results of that economic load dispatching control (EDC) for long- study confi rmed that a power stabilizer does have a period fl uctuations, and the like are performed. Each stabilizing effect on the output of wind farms, and control method requires a different power storage established a charge/discharge control method that capacity. Battery capacity has a signifi cant impact realizes the required functionality with the minimum on facility costs, and therefore, the smallest possible equipment capacity.

Power Electronics Technology that Supports Smart Grid 141 power is absorbed. The processing from data measure- 3.2 Usage of power electronics technology in power dis- ment and aggregation until the issuance of command tribution value is completed in a time of approximately 20 sec- The area-type stabilizer described in section 2 onds, and therefore compensation and demand/supply attempts to stabilize power over a wide area. The adjustment are possible for power generation fl uctua- “Demonstrative Project of a Regional Power Grid tions on the order of several tens of seconds. Because a with Various New Energies, Kyoto Eco-Energy Proj- general-purpose wide-area network (ADSL or ISDN) is ect” (2003 to 2007) conducted by the New Energy used for monitoring and control, the measurement and and Industrial Technology Development Organization control targets can be chosen without regard for dis- (NEDO) is introduced below as an example where sup- tance. The realization of a large-scale supply/demand ply/demand is adjusted and power stabilization is per- adjustment system at low cost is anticipated. formed in a relatively narrow area. Additionally, when performing balancing control An overview of the Kyoto Eco-Energy Project is with this system, adjustment corresponding to the shown in Fig. 3. In this demonstration project, biogas, amount of load fl uctuation is performed basically with photovoltaic and wind power generating facilities were a gas engine generator. In cases where the load fl uctu- established, and control to achieve a balance between ation per unit time is large and diffi cult to track with a demand and supply (5 minutes balancing control) was gas engine, adjustment corresponding to the amount of performed at specifi ed times between several preselect- load fl uctuation can be implemented as compensation ed end-users and a power plant where these renewable by a rechargeable battery. energies are used to generate power. The demonstra- The demonstration project aims to achieve balanc- tion project was conducted as joint research among ing control accuracy within 3% error in fi ve minutes, four companies and two government entities, and Fuji and the results obtained mostly satisfy this aim. As Electric participated mainly in the development of the a result, the project verifi ed that high accuracy can control system. be maintained even with control implemented via a In this system, sensors detect the generated output general-purpose communications network. Moreover, of photovoltaic power and wind power, and send moni- the effectiveness of rechargeable batteries as a means toring information to a control center via a communica- for controlling supply and demand in a smart grid was tion line. The control center calculates the recharge- confi rmed. able battery output to compensate for fl uctuation, and issues an output command to the rechargeable battery via the communication line. As a result, fl uctuation in the generated output of photovoltaic power and wind

Yasaka Kowaki substation substation For absorption of fluctuation Control of no. of In-plant Constant outpu operation load in natural energy power 125 kW units in operation 219 kW generation (100 kW, 30 min)

Secondary Fuel cell Gas engine generators Kazenogakko battery Kyoto 55 kW 100 kW 250 kW 80 kW×5 units

Control center Swiss village (wind power Food waste Methane gas supply materials Biogas generating facility (simultaneous supply-demand generation) 50 kW balancing control) Biogas power plant (Funaki district)

Acquisition of power generation and demand data To end-user, power generation, Wadano municipal Tsutsumi municipal substation measuring devices housing project housing project in Load Photovoltaic power 100 kW generation 30 kW in Kyotango City 7.5 kW Kyotango City 9.4 kW To end-user, power generation, substation measuring devices Tango Ajiwai no Sato Internet VPN ™ADSL ™ISDN Yasaka Municipal Hospital Yasaka District in Kyotango City Government office in 592 kW Kyotango City Load Photovoltaic power To end-user, power Yasaka Community Hall 100 kW generation 20 kW generation measuring 178 kW devices Wastewater treatment facility inYasaka-cho, Mizotani/ Remote Yoshino District monitoring

Fig.3 Overview of Kyoto Eco-Energy Project

142 Vol. 57 No. 4 FUJI ELECTRIC REVIEW 4. Power Electronics Devices in Smart Grids and devices must meet specifi cations for environmental Fuji Electric’s Future Initiatives resistance, and the heat exhaust of the system, seal- ing technology and the like are also important fac- Fuji Electric is advancing various initiatives aimed tors. For pole-mounted installations, a light weight toward constructing smart grids, and is also advancing is essential, and the future development of technol- the development of new technology for power electron- ogy that enables direct connections to high-voltage ics devices. This section describes technology essential systems and eliminates the necessity for a transformer for developing smart grids in the future. is needed. A fanless implementation is also needed for maintenance-free operation and to reduce cost. To 4.1 Power electronics devices for power distribution develop equipment that fully satisfi es the functional In power systems, large-scale centralized power requirements of power distribution devices, the com- generation plants are responsible for power genera- mercialization of next-generation devices made from tion, transmission and distribution equipment are re- silicon carbide (SiC) or the like is considered to be sponsible for power distribution, and the end-users are necessary, and therefore some time will be needed be- responsible for consumption. Electric power fl ows from fore such devices can be used in practical applications. large-scale centralized power plants toward end-users, and power systems have been constructed assuming a 4.2 Smart PCS

one-way fl ow of power from upstream to downstream. The DC-side of a PCS is connected to solar panels, feature issue: Smart Community In recent years, end-users have generated power rechargeable batteries, capacitors (including electric by using home-use solar power generators and the double-layer capacitors), etc. In the case of solar pan- like, but if they were to install a large amount of dis- els, a photovoltaic PCS is connected; for rechargeable tributed power sources, the fl ow of power, at least in batteries, a power storage device is connected and in the distribution system, will not be unidirectional (see the case of a capacitor, a static var compensator is con- Fig. 4). Additionally, because the amount of power nected. The inverters used have many common parts produced by generation from renewable energy cannot in their confi gurations. A smart PCS is a multi-func- be controlled, new methods will be needed to manage tion inverter provided with the required communica- the distributed power sources, and specifi c areas or tion capability and a system interconnection function, wide areas in order to control the frequency, voltage or and has a confi guration suitable for multi-purpose ap- power fl ow. plications. Examples of power electronics devices used to solve Standardization of the PCS communication speci- these types of power distribution system problems are fi cation is being advanced by the Japanese Ministry of the self-commuted static var compensator for distri- Economy, Trade and Industry (METI), and standards bution and a distribution line loop balance controller for the communication interface, protocols and the (LBC). For power electronics distribution devices to like are expected to be established in the future. Fuji become widespread, they must be compatible with out- Electric plans to move ahead with the development of door and pole-mounted installations, provide mainte- a PCS equipped with these standardized functions and nance free operation, have a low price, and so on. that is suitable for multi-purpose applications. To support outdoor installation, power electronics System interconnection functions include an LVRT

Power flow direction becomes complex according to amount of distributed power sources Distribution substation Smart PCS

Large-scale power source

Output Bi-directional command Control converter device DC voltage, current

PCS for distributed power source ™Power stabilization function ™Reactive power adjustment function : Distributed power source Communication ™Power storage function Solar panel : Switch Storage cell cable Electric double-layer capacitor, etc. Fig.4 adoption of renewable energy in a power distribution system Fig.5 Overview of smart PCS conﬁ guration

Power Electronics Technology that Supports Smart Grid 143 function, an isolated operation detection function, an the same power supply package confi guration regard- interconnection protection function, and so on, and less of the power system type, i.e., advanced country through incorporating these functions and standard- type (US, Europe), developing country type (urban izing the equipment, various types of standardization type, rural type), or isolated island type, and by chang- will be supported (see Fig. 5). ing the control method according to the application target, power supply devices will be easily confi gurable, 4.3 New energy power supply package and will be applicable to many systems without chang- Aiming to expand the utilization of renewable ing their hardware specifi cations. For this purpose, energy, and in order to facilitate the adoption of new scalability, safety and security, and maintainability energy, a new energy package constructed so as to (maintenance-free operation) must be realized. combine a power generator and a power storage device Scalability is the ability to expand system capac- is desired. ity according to demand, and in addition to increasing In the METI system forum fi nal report concern- device capacity, the ability to connect various power ing smart communities, power system types were sources and to achieve system-wide harmonization compared by classifying them into the fi ve categories easily are required. Safety and security are the ability shown in Table 1. to operate safely at all times and in various locations, If relatively small-capacity power supply devices even when operated by persons lacking experience that use renewable energy can be packaged and ap- with electricity. Good maintainability means to have a plied for various purposes regardless of the power low failure rate, and to be easily serviceable in the case system confi guration or type of renewable energy, then of a failure. renewable energy will become easier to use. By using The new energy power package incorporates a

Table 1 Power system characteristics

Power system type Operating method Advanced country type (US) The distributed power sources are connected to a strong power system. In this case, mainte- Advanced country type (Europe) nance of the frequency and voltage may depend upon the power system, and effi cient opera- Developing country type (urban type) tion of the distributed power sources becomes important. Since there is no pre-existing power system, the distributed power sources themselves con- stitute the core power supply. For this reason, the distributed power sources are responsible Developing country type (rural type) for constantly maintaining the frequency and voltage, and the ability to absorb fl uctuations in the load as well as output fl uctuations from other distributed power sources is essential. The distributed power sources are connected to a weak power system. In this case, the out- Isolated island type put of the distributed power sources may affect the power system. Accordingly, the state of the power system must be evaluated while operating the distributed power sources.

Power station Local micro-grid Hydrogen Local micro-grid Thermal power Fuel Storage Wind-power Power stabilizing equipment Heat Hydropower cell cell generation Locally installed storage cell Nuclear power Power system monitoring and GE control systems Local power station PCS INV SVC PCS

LRT Regional energy Next-generation distribution Load dispatching management system automation systems center LBC PCS IT switch INV PCS SVR Area-type power Mega Solar stabilizing Smart house Customer’s system Wind farm Storage equipment cell Smart meter REMS LRT: Load Ratio control Transformer Solar PCS PCS UPS SVR: Step Voltage Regulator power Charging BEMS generation device FEMS SVC: Static Var Compensator GE Load LBC: Loop Balance Controller Fuel Gas Storage Solar power PCS: Power Conditioner Heat cell engine cell generation UPS: Uninterruptible Power Supply INV: Inverter REMS: Retail Energy Management System Retail store Factory Commercial building BEMS: Building and Energy Management System FEMS: Factory Energy Management System Power electronics devices

Fig.6 Areas of applied power electronics technology in the “Fuji Smart Network System”

144 Vol. 57 No. 4 FUJI ELECTRIC REVIEW PCS for photovoltaic power generation and a PCS for tion system is collected by an energy management sys- storage cells into the same package, and is optionally tem (EMS), which monitors and controls the entire sys- confi gurable as a system compatible with small-scale tem. The EMS issues control commands to devices in hydropower, wind power or the like. order to achieve energy effi ciency, and the power elec- Fuji Electric plans to develop a new energy pack- tronics devices respond to the commands quickly and age suitable for multi-purpose applications and to use accurately to support the realization of high effi ciency. this with smart grids. 5. Postscript 4.4 “Fuji Smart Network System” Figure 6 shows the areas of applied power electron- Smart grids are a part of the public infrastructure ics technology in the “Fuji Smart Network System.” and assure energy security by incorporating a diversi- With the Fuji Smart Network System, in both the in- fi ed range of power supplies to eliminate a dependency dustrial and consumer sectors, end-user microgrids are on fossil fuels, which traditionally had been the pri- constructed, and hybrid power supply equipment that mary source of energy. Additionally, the transition to combines photovoltaic power generation systems, stor- use of a smart grid entails not only modifi cation of the age cell PCS, fuel cells and the like is introduced to the power system, but also asks the question, in regard system. Moreover, in the distribution system, regional to energy generation and consumption, of what is the

microgrids are confi gured by combining conventional ideal grid confi guration in which users can participate. feature issue: Smart Community load ratio control transformers (LRTs) and step voltage Aiming to protect the global environment, the regulators (SVRs) with reactive power compensation stage is now being set for the creation of a sustain- equipment for voltage stabilization, loop balance con- able energy system for future generations. In order trollers (LBCs) for power fl ow control, power stabilizers to realize such an energy system, the capability of fi ne to absorb fl uctuations in renewable energy, and the control of energy is prerequisite. Such capability can like. Additionally, in the power transmission system, be achieved with power electronics technology, and the an area-type stabilizer is installed to stabilize the sup- role of power electronics technology in smart grids will ply of power within a region. continue to increase in importance. With the goal of With the Fuji Smart Network System, information expanding usage of smart grids, Fuji Electric intends from smart meters and from IT devices in the distribu- to continue to improve power electronics technology.

Power Electronics Technology that Supports Smart Grid 145 Integrated Energy Management System Platform

Hiroshi Horiguchi † Kenichi Ishikawa † Yoshikazu Fukuyama †

ABSTRACT

Fuji Electric has developed an integrated energy management system (EMS) platform that can visualize energy consumption and integrate energy-saving controls in various ﬁ elds such as iron and steel production , general indus- t ries , retail distribution, water treatment, regional communities and so on to provide energy management functions expeditiously and at low cost. The platform is compatible with models of various energy types such as electric power, gas, water and heat energies and can realize optimal energy-saving control even with renewable energies. Various web screens support local languages, and systems ranging in size from a small single-server system to a system consisting of several tens of servers can be developed easily using the same engineering tools.

1. Introduction heat, etc.) facilities, the EMS platform shall have ability to optimize each type of energy and The Japanese government’s setting of medium- to selectively implement optimization and con- term targets for cutting greenhouse gas emissions (cut- trol functions according to goals regardless of ting emissions by 25% from 1990 levels by 2020), revi- the industrial fi eld sion of the “Law concerning the rational use of energy” (b) In accordance with the size of a user’s energy (energy saving law), the international standard (ISO facility, systems ranging in size from small-scale 50001) concerning energy management to be issued systems with a single server to large-scale dis- this year, and the like are measures that address the tributed systems with multiple servers, shall be urgent need to prevent global warming. Additionally, constructible quickly and easily with the same many smart communities, aiming to realize a global engineering operations sustainable society, are proceeding with efforts to use (c) Even during online operation, it shall be pos- new forms of energy and to conserve energy. To attain sible to conduct system enhancement and evalu- these goals, the entire supply and demand of energy ations with simulation when adding or renewing must be integrally managed and operated, and for this energy equipment. purpose, energy management systems (EMS) will have a greater role than ever before. 2.2 Software confi guration Fuji Electric has developed various EMS focused Figure 1 shows the integrated EMS platform and on the energy supply chain in the fi elds of power, its peripheral software confi guration. The software iron and steel, water, industry, retail distribution, confi guration is the same as that of a typical EMS, etc. The functions of a cluster EMS (CEMS), factory and consists of software for various Web screens, EMS (FEMS), building EMS (BEMS), and retail EMS performance data management, optimization/control (REMS) have been integrated into a single platform program groups, and driver management that controls to develop an integrated EMS platform for providing communications with fi eld sensors and control equip- EMS functions that meet various onsite needs, rapidly ment and the like. The most prominent features of and at low cost. this platform are the “Fuji Service Bus” high-speed program linking service that can associate various 2. Confi guration and Functions functions, the “Field Connector” high-speed data sharing service and the integrated energy network model 2.1 Development concepts that unifi es various control targets. As needed, an The integrated EMS platform is important middle- EMS ranging in size from a small-scale single-server ware that forms the core in the construction of an system to a system consisting of multiple large-scale EMS. The development concepts of the EMS platform distributed servers can be constructed on the same are listed below. platform, with the same engineering operations and (a) For various types of energy (electric, gas, water, within a short time. Functions of the core integrated EMS platform as † Fuji Electric Co., Ltd well as its peripheral functions are described below.

146 Scope of integrated Optimization/ Performance data EMS platform Various Web screens control program management

Web Web Web Performance data Optimization/ Plant diagrams Performance data management service Optimization/ control program Various systems diagrams analysis screen control program Work screen Warning screen Performance data group (add-on use) Multi-tenant Global language support management

“Fuji Service Bus” high-speed program linking service

Enterprise Service Bus

Integrated energy network model (control target model)

Integrated engineering tools “Field Connector” high-speed data sharing service feature issue: Smart Community

Communication driver manager

Communication driver Communication driver Communication driver Communication driver

Fig.1 Integrated EMS platform and its peripheral software conﬁ guration

gineering tools (to be described later) by the user, the 2.3 “Fuji Service Bus” high-speed program linking service Fuji Service Bus instantaneously acquires the server According to the size of the control target, the allocation information for program even when opti- number of required software functions, the monitor- mization/control programs are newly added or existing and control cycle, and required server redundancy, ing optimization/control programs are transferred be- an EMS may be constructed as a system ranging in tween servers in accordance with CPU load conditions. size from a single-server confi guration to a large-scale Consequently, work tasks can be performed while the distributed confi guration consisting of several tens of system continues to operate. servers in a CEMS or the like. Moreover, because the optimization/control pro- The “Fuji Service Bus” is a mechanism for link- gram groups previously developed for various industri- ing, without awareness of these types of differences in al fi elds used various different languages (C, C++ and server confi gurations, the processing among optimiza- Java), they could not be made to interact easily with tion/control programs distributed in each server, and each other. The Fuji Service Bus, however, enables among Web screens and optimization/control pro- mutual interaction regardless of the development lan- grams. guage. As a result, Fuji Electric’s EMS software assets Traditionally, program calls in a distributed envi- can be provided seamlessly. ronment were implemented as a “program X residing In the future, by linking the Fuji Service Bus with on server Y”, with the server allocation information a general Enterprise Service Bus, standard linking for each program having been defi ned in advance. For with global-standard core software will be realized. this reason, when adding servers or changing the server confi guration due to an increased number of control 2.4 “Field Connector” high-speed data sharing service targets, a system engineer would have to shut down With the Fuji Service Bus, each program is able to the system, and redefi ne the server allocation informa- interact mutually, regardless of the server on which tion for each program. it is allocated. However, in order for each program to With the Fuji Service Bus, however, rather than perform actual operations and control, an environment requiring server allocation information defi nitions in in which each program, regardless of the server on advance for programs, the relevant program resid- which it is located, is able to reference online data and ing on any server can be called using only the service issue control instructions is necessary. This capability name (program function name). This is because the is realized with a mechanism known as the “Field Con- Fuji Bus Service exchanges information dynamically nector.” and in real-time with the service name list residing in The Field Connector manages online data with each server. TAG management (data management method using As a result, with easy operation of integrated en- a TAG name such as “TAG0001” and a corresponding

Integrated Energy Management System Platform 147 TAG value). In contrast to a typical TAG value that realized. As a result, energy network model defi nitions only accommodates a single integer or fl oating-point can be made with the same engineering operations, value, the Field Connector TAG value is a string of regardless of the type of optimization control program variable length. As a result, TAG values can be stored to be applied. by handling 30-minute power generation planning Fig. 2 shows an example representation of an inte- values and other continuous numeric data as comma- grated energy network model. separated character string data. For example, TAG With this model representation scheme, equipment management can also be used effectively for linking is placed at nodes, and connections between equipment data (24-hour continuous data in units of 30-minute in- are represented with a node-branch model that con- tervals) among programs in the sequence shown below. nects branches to the nodes. Additionally, defi nitions (a) Power demand forecasting program of energy conversion characteristics (effi ciency, etc.), (b) Optimal power generation planning program for maximum output power, TAG names for obtaining the each generator according to the power demand real-time status of fi eld equipment, TAG names for forecast value control output destinations, and the like are defi ned (c) Generator control program conforming to opti- as properties in the nodes. Integrated management is mal generated plan performed in advance to control which types of proper- Additionally, because Field Connectors on all serv- ties are required for each of the various node devices. ers are mutually linked and the Field Connector on The model defi nitions are output as xml data, and each server performs TAG value management for all prior to use, are converted into the model representa- the servers, programs that reference and update TAG tion format used by the optimization/control programs values can run without problem regardless of the serv- in each fi eld. er on which they reside. For the creation of power system models, a func- In addition to use for data linking among pro- tion that converts between the common information grams, Field Connectors also are provided with a func- model (CIM) of IEC 61968 and IEC 61970 and an inte- tion for connecting to fi eld devices via a communication grated energy model network model is being developed driver manager. The online data obtained through to facilitate the incorporation of existing power system communications with fi eld sensors and control devices equipment data. is managed as TAG values, and TAG values set by control programs can also be output directly to the fi eld 2.6 Performance data management service devices. The performance data management service is a Thus, with a Field Connector, data can be shared feature that periodically extracts TAG values from the among various programs from any server, online data Field Connector, accumulating and managing those of the entire system can be referenced, control signals values as performance data. Through the use of an en- can be output, and a system that meets various needs ergy analysis function, provided as a standard feature, can be confi gured and built easily. the energy usage status can be analyzed in an easy to A Field Connector is able to manage 500,000 TAG understand manner. values system-wide. With the performance data management service, performance data is linked in advance to an equip- 2.5 Integrated energy network model ment hierarchy consisting of, for example, business of- An energy network model defi nes how electricity, fi ce and plant, building, line and device levels, so that gas, water, heat and other forms of energy are convert- energy across an entire company or at an arbitrary ed and transmitted by each device. hierarchical layer can be tallied instantaneously. As To optimize energy and control the balance between supply and demand, the various optimization/ Node Node control program groups must be commonly aware of Branch Purchased Amount of electric power Electric the energy transmission of the control target. Previ- power power load Amount Amount ously, with optimization/control programs in various Amount of of electric Purchased of fuel steam Electric power fi elds, different types of model representation methods Boiler power Amount fuel generator of were applied in order to process calculations with the steam Steam Amount Amount load of of electric steam Electric power highest effi ciency. As a result, models had to be de- Boiler power fi ned with engineering tools that differed for each opti- generator Amount of steam Amount ( 1) of electric mization/control program that was applied . Electric power power On the other hand, to simplify the engineering generator Amount of steam Amount of work to be performed by users, the representation Amount of fuel steam method and data structures were prescribed so that Boiler an intuitive easy-to-understand common integrated energy network model, which does not depend on the Fig.2 Example representation of integrated energy network optimization/control program to be applied, could be model

148 Vol. 57 No. 4 FUJI ELECTRIC REVIEW a display method, a confi guration graph of energy type tions, and the servers at which the optimization/con- (gas, heavy oil, coal, electric power, etc.) and a confi gu- trol programs should be positioned are specifi ed. This ration graph of energy application (power, air condi- completes the engineering work. tioning, lighting, etc.) can be indicated with equivalent The integrated engineering tool automatically posi- amounts of t-CO 2 (carbon dioxide equivalent tons) or tions the screen programs and the optimization/control crude oil. Moreover, arbitrary measurement data can programs in each server according to the content of the be combined and displayed graphically, or may be function settings. output to spreadsheet software for the user to perform their own analyses. 2.8 Simulation environment In actual energy analysis, the production quantity, In the screenshot of Fig. 4, the model and various operating time and the like are important consider- work functions are positioned under “ONLINE,” but ations. The performance data management service is simply by pasting the models and the various work able to associate and manage a variety of data in ad- functions under “SIMULATION,” operation can be ver- dition to energy data in the equipment hierarchy, and ifi ed under a simulated environment that differs from energy analyses can be performed horizontally across the ONLINE environment. the hierarchical equipment locations (see Fig. 3). The purpose of the simulation verifi cation is to The performance data management service also evaluate the effect of adding a new energy facility to

has a multi-tenant management function. This func- the model, or to evaluate the validity of energy saving feature issue: Smart Community tion, if incorporated into a software as a service (SaaS) control output based upon a change in the control pa- environment, allows even a single server to provide rameters, or the like. the performance data management service to multiple So that simulations can be realized, the Fuji companies (tenants) simultaneously. Service Bus, Field Connector and performance data This service is provided in order to visualize en- management service are each provided with two differ- ergy data acquired from the various homes, buildings ent environments, online and simulation. As a result, and companies in a smart community, and is an effec- various verifi cation tests can be performed while online tive means for raising awareness of energy conserva- operation continues. tion. Especially with the simulation environment of the Field Connector, the control output to TAG manage- 2.7 Integrated engineering tool ment is limited to the TAG value setting, without be- The integrated engineering tool was developed so ing linked to the actual control devices, and is recorded that users could construct a system easily, and by posi- as control performance data in the simulation environ- tioning user screens and work functions as in Windows ment and displayed graphically so that the validity of Explorer, screen programs and optimization/control control commands can be verifi ed. programs are positioned automatically for each server. Figure 4 shows an example screenshot of the integrated 3. Application to Community Energy engineering tool. Management Systems First, the network energy models and various work functions (sets of programs combining optimization/ An example system confi guration when this EMS control programs and their work screen programs) is applied to a cluster energy management system which are operated for the model as needed are posi- (CEMS) is shown in Fig. 5. tioned in the function hierarchy column on the left-side The servers in a CEMS all use a redundant con- of the screen. Then, on the right-side of the screen, function settings are made for the various work func-

Equipment hierarchy management Energy Manufacturing Maintenance ・・・・ analysis management management TOP support

＋ Plant 〇〇 Plant ロロ Plant ロロ Plant ロロ Plant ロロ－ Plant ロロ Energy Production Operating ・・・・ volume time ＋ Building AA

－ Line ×× Line ×× Line ×× Line ×× Line ×× Energy Production Operating ・・・・－ Process ×× volume time

Machine ×× Machine ×× Machine ×× Machine ×× Machine ×× Machine ×× Energy Production Operating time ・・・・ volume ＋ Process ××

＋ Line ××

＋ Building BB

Fig.3 Energy management centered on equipment hierarchy Fig.4 Integrated engineering tool screen example management

Integrated Energy Management System Platform 149 Planning system server Monitoring and control server Demand high-speed Customer management control server server Service programs Various Web screens Service programs Service program Power demand forecast Monitoring and control plant diagram screen Cost optimization Demand response Supply/demand Demand balance graph, etc. operation control operation plan Customer management screen Demand balance control Warning screen Work stoppage plan Frequency control Power interchange Planning operation screen plan Voltage control Global language support Fuji Service Bus Fuji Service Bus Fuji Service Bus Fuji Service Bus Integrated energy Integrated energy Integrated energy Integrated energy network model network model network model network model Field Connector Field Connector Field Connector Field Connector

Firewall

Performance data server Front communication server Information service Field Connector SOA server Fuji Service Bus Field Connector Field Connector Performance data management Fuji Service Bus Fuji Service Bus Multi-tenant management Communication driver manager Global language support Various control device drivers Various Web screens, Database Monitoring and control HEMS/BEMS linked drivers services Web terminal Smart meter linked drivers Energy analysis screen Weather information leading Various data provision driver service

Firewall

Wide-area network line

Fig.5 Example CEMS conﬁ guration with integrated EMS platform

fi guration in order to improve reliability. The moni- distributed to each server for the purpose of load distri- toring and control servers are provided with server bution. These programs can be called from any server functions for all Web screens, and the performance via the Fuji Service Bus, and their locations can be data server manages the database. Various other serv- changed according to the system operating load. ers are confi gured as independent servers in order to Thus, with the powerful distribution-supportive distribute the CPU load. In the future, front commu- platform of the Field Connector and Fuji Service Bus, a nication servers that communicate with the fi eld and large-scale EMS can be constructed easily and quickly. information provision SOA servers that provide energy The newly developed EMS platform is slated for visualization services to homes and building manag- evaluation as part of the “Next Generation Energy ers can be added according to the number of connected System and Public System Demonstration” being pro- communication targets and the increase in number of moted by the Japanese Ministry of Economy, Trade concurrent accesses. and Industry in Kitakyushu City and elsewhere. By mounting a Field Connector in each server, the on-site TAG values received by the front communica- 4. Postscript tion server can be referenced by each server. More- over, by writing data to the fi eld TAG, the monitoring This paper has introduced Fuji Electric’s inte- and control server, demand/supply and high-speed grated energy management system (EMS) platform. control server, and the end-user management server The EMS is evolving from discrete optimization to can implement control via the communication driver total optimization. This EMS platform, with which in the front communication server. Additionally, the the overall EMS status can be acquired and controlled optimal generator operation planning value calculated from any server, is effective in realizing more advanced with a planning server is sent to the demand/supply total operation. Fuji Electric intends to continue to en- and high-speed control server as a TAG value, and is hance engineering tools further, to provide EMSs that used as the balance control target value. are easy to use and have an impact in terms of their The various optimization/control programs are performance and pricing, and to contribute towards the

150 Vol. 57 No. 4 FUJI ELECTRIC REVIEW realization of sustainable society. erational planning system for energy plants in steel- works”, Proc. of IFAC World Congress, 2008-7. References (1) Fukuyama ,Y ., et al. “Development of an optimal op- feature issue: Smart Community

Integrated Energy Management System Platform 151 Supplemental Explanation

Isolated operation detection method

Typically, during a power system outage, distribu- methods in combination. tion line circuit breakers are open and the distribution (a) Passive method line is in a no-voltage state, but in a distribution line The passive method detects sudden changes in to which distributed power sources such as solar power the voltage phase or frequency caused by an imbal- generation are connected, if operation continues while ance between the generated power output and the not disconnected from the power system, the region load during the transition to isolated operation. that should be in a no-voltage state becomes charged. (b) Active method Thus, in a power system that has been disconnected The active method continuously applies fl uc- from a commercial power supply, isolated operation is tuations in voltage and frequency via a power con- the state in which only the power supplied from the ditioner control system and an externally attached distributed power sources causes electricity to fl ow resistance, and detects noticeable fl uctuations dur- through the distribution line. ing the transition to isolated operation. During isolated operation, there is the risk of serious effects on human body and equipment, such as: (1) electric shocks to the general public, (2) equipment Distributed power source damage, (3) adverse effect on fi refi ghting operations, (4) electric shocks occurring during the search for ～～ Load Load fault locations and during removal operations. In addition, expansion of the damage at the fault location or Fault Commercial Transformer occurrence a delay in recovery may disrupt the supply of power. power due to isolated operation of a Therefore, when connecting distributed power sources CB distributed power source to a power system, isolated operation prevention mea- (Circuit breaker) sures are mandatory, and they must detect, either di- Distribution line fault detection rectly or indirectly, the isolated operating state using →Open circuit breaker causes disconnection a protective relay or the like, and then rapidly discon- from distribution system. nect distributed power sources from the power system. There are two methods for detecting isolated oper- Figure: Failure due to isolated operation ation, and detection is implemented using both of these

152 Vol. 57 No. 4 FUJI ELECTRIC REVIEW Overseas Subsidiaries

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