63rdAMEUConvention2012 Demystifying the smart grid by Stuart Michie, ABB The principles of the technology of today’s power grids have not changed significantly in the past 100 years. Electricity is a product that has to be generated at the time of need. The level of power generation is set to match the instantaneous demand. With the constraints in power resources, this has to change, hence the development of the smart grid. This paper investigates some of the concepts picture of the status of the system is needed. As an example, a sophisticated outage around the idea of the smart grid, with the Better utilisation needs to be made of management system can exchange purpose of showing that implementing a existing assets. More intelligent investment information with a SCADA system, a smart grid is not the application of a single decisions need to be made. Knowing the geographical information system, a metering technology, but the collective result of a real time status of the elements of the power system, a customer management system, a system design with the application of many grid are key to achieving this. Integrating crew management system and a call centre technologies and products. It is important that the realms of operational technology and to provide a dynamic, real time fault and a utility takes a holistic view of individual smart information technology is essential to realise planned outage management for a utility. grid related projects in order to get the many the vision of the smart grid. The key concept is Systems thinking components to work together and achieve integration. better utilisation on capital spent. When planning an investment in a technology, Technology it is advisable to take a “systems view” Vision of the smart grid Operational technology approach. For example, installing an Around the world, and in South Africa, it has automatic meter reading system (AMR) to Operational technologies are the systems and become evident that utilities need to do more manage payment and customer connections devices that allow the physical monitoring with less. Constrained power availability, provides useful functionality. Broadening the of a power system, such as basic SCADA, scope to an advanced metering infrastructure rising demand, environmental pressures, RTUs, protection relays, meters and (AMI) with two way communications provides cost pressures, skill shortages and limited communications. Operational technologies more possibilities for smart grid integration resources have all led to increasing pressure provide the measurements, indications and and associated benefits. on the power grid. control interfaces to physical plant in the Making the meter information available from The digital age has placed increased demands power system. The more detailed information the AMI system to provide customer outage on the quality of supply, while new alternative provided, the better a power system can be information to an outage management system sources of generation have made the modelled and controlled. increases the value of the investment. reliability of supply more unpredictable. The Information technology configuration of the power grid is changing This requires the correct specification up front to realise these synergies (e.g. meters report from having centralised generation (Fig. 1) Information technologies are the enterprise outages within a short time period rather with one-way power flow to end-consumers software systems that enable the management than only reporting metering data once a to having distributed power generation and and operation of a power system. Examples day). Using the same system to feedback consumption (Fig. 2). No longer can the of information technology systems are outage information to consumers adds another assumption be made by a consumer that the management, distribution management, asset benefit, while using the same infrastructure. power grid is an infinite source of energy that management and advanced SCADA (Fig. 3). can be tapped at will. Four key areas Integration of the operational technology To successfully operate a power system world and the Information Technology world There are four key areas that must be under these conditions a clear real time brings significant benefits to a utility. considered to implement the smart grid Fig. 1: Traditional power grid. Fig. 2: Power grid of the future. 63rd AMEU Convention 2012 45 63rdAMEUConvention2012 information technology world to analyse the history. From an outage management system, fault causes, durations and other statistics for performance measurement can be derived automatically. This provides better information that automatically leads to improved reporting quality to the regulator and the ability to manage future events better. From an asset management system, non-operational data can be used to track the health of assets for condition based maintenance. This leads to better performance of assets and reduced maintenance costs. Scarce skills can be utilised more effectively. Integrating new technology Integration of new technology is the final key area of the smart grid. While these might not be prevalent in South Africa yet, they will Fig. 3: Integration of operational and information technology. come as demand from customers grows. When they arrive, electric vehicles will place significant new demands on power distribution Communications far better to be able to inform a customer infrastructure. This needs to be managed that calls in to report a fault that the fault is Communications is key for enabling the in real time, such as with real time pricing known and when the estimated restoration smart grid. Without a reliable, all-reaching of electricity to manage the demand for time will be. communication network, it will not be charging. Electric vehicles can also be used as a source of storage for utilities, where power possible to realise the full benefits of the Distribution automation smart grid. Our daily lives are being improved can be bought back from customers to assist The second key to the smart grid is distribution by the continuous improvement in mobile with meeting demand at peak times. automation. Monitoring and automation of communication technologies, which are Interconnection of renewables, such as high and medium voltage plant allows better enabling whole new applications such as management and control of the power system wind and solar, will bring a new dynamic live traffic enabled GPS and personal instant plant, thereby leading to better reliability and to the power system. These are variable messaging. The same is needed to enable better efficiency. Outages are detected quickly sources of power that are not predictable. the smart grid, with the ideal being to have and can be dealt in a shorter time, thereby Consumers will also become producers with two-way communication enabled right to the reducing customer minutes lost. the management of distributed generation end devices in each consumer’s installation. requiring incorporation into power system. Traditionally SCADA monitoring has been There is no one size fits all communications Local area power storage is another new applied at the HV to MV substation level. technology being explored. Power is stored solution. Different technologies are applied Today equipment is readily available to in a medium voltage network using a storage to the core network, the distribution area extend monitoring down to the secondary facility such as a battery bank. This is used to network, the neighbourhood area network distribution level, greatly extending the reach bridge short term variations between demand (NAN) and the home area network (HAN) of monitoring to make distribution automation and supply and helps reduce the effect of (Fig. 5). possible. intermittent renewables. New technologies are being developed and The provision of fault current measurements existing technologies are being improved and earth fault indicator operation leads to Advanced meter infrastructure in ways that allow the implementation of the possibility to have a self-healing grid. While the main purpose of an automatic communications for the smart grid. For the Dynamic algorithms in the SCADA system meter reading system is the management of backbone there are the existing multiplexer can sense when a fault has happened and, billing and payment for electricity, there are type network technologies (SDH, PDH) using based on real time loading and back feeding many other benefits that can be derived from fibre optic and microwave radio. For the NAN capabilities, devise and, optionally, execute a installing an advanced metering infrastructure there are wireless mesh technologies that switching plan to restore supply to as many (AMI). Using two-way communications create a self-configuring and healing network. customers as possible. systems, these systems can be used to provide For the last mile there is power line carrier Loss reduction through Volt-var control is useful information for other systems that make (PLC) and for the HAN, short range radio another benefit of distribution automation. up the smart grid. Real time information can technologies such as Zigbee and Bluetooth Best suited to rural networks, algorithms on be used by an outage management system At the medium voltage level, a good a SCADA system can be used to manage to provide indication of power outages and communications network supports the capacitor switching on medium or high restoration. Before a customer is even aware implementation