PHOTOVOLTAICS CENTRAL INVERTERS Optimise costs, increase revenues Markets are different But the markets are subject to different conditions, according to Casini: investors and operators in Asia accept shorter maintenance cycles with increasing personnel requirements if the initial cost is low. In Europe and North America, the situation is exactly the opposite, because here the labour costs are higher. “In order to offer the right solutions for each market, Power-One will continue to diversify its product port- folio and include central inverters for both mature and emerging markets,” says Casini. Schweikardt of Sputnik is thinking more of the German market when he says that an investment in PV has to be profitable despite reduced funding, and that it is therefore important that an investor can get the greatest possible amount of energy at the lowest possible cost. For this reason, it is not only Sputnik that is trying to accommodate more powerful central inverters in a station solution, thereby reducing the number of stations needed as well as the acquisition cost. “In addition, we think it is very important,” Schweikardt continues, “that our products can be in- stalled quickly and easily to keep time and material Photo: REFUsol costs as low as possible.” More capacity in the same space – with this strategy, News from the manufacturers manufacturers of central inverters intend to help reduce However, many manufacturers are not just working the investment costs of PV power plants. Some of the on more powerful central inverter stations, but also on system improvements, such as increasing the op- system improvements that will probably be seen at erating voltage from 1000 V to 1500 V, or improving the collaboration between the plant and the trans- Intersolar 2013 serve the same purpose. mission system operators through increased moni- toring and control capabilities. hen asked about trends, concepts and de- AEG Power Solutions (AEG PS) has long been es- velopments in central inverters, Paolo tablished as a global player in the field of solar tech- W Casini, Vice President of Product Marketing nology. The product range of the business area at Power-One, responded that the market currently has Renewable Energy Solutions (RES) includes solar in- two faces: in European markets, demand is declining, verters, monitoring and control systems as well as with the exception of the market in the UK, while in- power controllers for solar power generators of all creasing in the growing PV markets in North America, sizes. The new central inverter PV.800 from AEG PS is India, China and Japan. But it does not matter which the latest member of their Protect PV product family, market you look at, the most important factor is always which is used in PV power plants. The recommended the total cost that the operator of the plant has to bear. PV DC power is specified at 800 to 1300 kW, the rated Hans-Georg Schweikardt, Head of Product Management AC output at 880 kVA at 25 °C and 800 kVA at 50 °C at Sputnik Engineering AG, comes to a similar conclu- ambient temperature. The DC voltage window ranges sion: “One of the biggest challenges to surviving in the from 490 to 1000 V according to the data sheet, the PV market in the long term is that you have to develop maximum permissible DC current is 1440 A and the products that are both state of the art technology as UMPPT voltage range is between 573 and 850 V. The well as cost effective.” efficiency according to EN 50530 is at almost 98.15 %. 34 Sun & Wind Energy 4/2013 Sun & Wind Energy 4/2013 35 PHOTOVOLTAICS CENTRAL INVERTERS Communication between the PV power plant compo- nents is based on Modbus and CAN bus, which runs between the containers via fibre optic cable and Ethernet. This structure allows for continuous moni- toring, including error analysis and regular reporting. For over 50 years the Italian group Bonfiglioli Riduttori S.p.A. from near Bologna has produced electrical drive systems, including frequency convert- ers. In view of the growing “green economy”, the next logical step was to start making solar inverters, which they incorporated into their product range. The as- sortment of inverters, designed for industrial PV sys- tems, ranges from 30 kW compact units up to modu- lar turnkey solutions with 3 MW capacity. They are manufactured in the factory of Bonfiglioli Vectron ABB central inverter PVS800 Photo: ABB Automation Products GmbH in Krefeld, Germany. In 2012 Bonfiglioli unveiled their new inverter modules. The devices fulfil all requirements regard- product range, RPS Endurance. The unit is more ro- ing interference immunity and reliability. Bosch bust and compact than the average inverters of this Power Tec specifies the maximum efficiency at 98.7 % performance class, according to the company. And it and the European efficiency at 98.5 %. The VC 250 is requires only minimal effort for transportation, instal- the only central inverter with a transformer. lation and maintenance. The product description “Our new central inverter PVS800 is one of the mentions other features: most attractive solar inverters on the market,” says A novel two-stage encapsulation concept pro- Nannette Baur from ABB Automation Products GmbH. vides optimal protection of the inverter components. This praise is due to its compact and modular design The device has an innovative cooling and environ- and its improved efficiency values, ranging between mental protection concept. RPS Endurance systems 98.6 % (maximum) and 98.2 % (European efficiency). are compliant with applicable international grid con- ABB central inverters with a capacity of 100 to 500 kW nection regulations and are suitable for composite are used in systems with multiple MW capacity and in operation in large-scale PV systems ex works. Finally, mid-size facilities in industrial and commercial build- a few details from the data sheet: AC rated output ings. Among numerous other certificates, the PVS800 500 kW; maximum DC input voltage 1000 V; weight has now been granted the Golden Sun certificate, <1000 kg; efficiency 98.6 % (advised). which is necessary for the Chinese market. As the Large PV systems not only need a central invert- company reports, a few months ago a new production er, but also usually a medium voltage transformer, line for the PVS800 went into operation on location in switchgear, and a monitoring system. For this reason, Bangalore, India. The Indian PV market is one of the Bonfiglioli: “more robust and it makes sense to place everything as a complete fastest-growing worldwide. “For our new production compact than the average package in a central inverter station. For this, Bosch line, there are already orders with a volume of more inverters of this performance Power Tec GmbH has complete systems readily avail- than 200 MW, the first of which had already been de- class” Photo: Bonfiglioli S.p.A. able; among others, the VIS 1050 and 1400 station, livered at the end of 2012,” says K. N. Sreevatsa, intended for PV facilities with high-performance mod- Local Business Unit Manager for ABB Power ules, and the VIS 400-600 are the smallest models in Conversion in India. The annual capacity of the new this series, which accommodate only two inverters plant amounts to 500 MW. (VC series). “Our turnkey inverter stations in the “With the Fronius Agilo, we have developed a VIS series are the ideal solution for rapid planning central inverter with the installer in mind: easy and error-free commissioning of large solar power plants,” says Senior PR Manager Christoph Lapczyna. “All components and the ventilating system are fac- tory installed and tested. The stations of the VIS se- ries are type-tested and ensure operators and inves- tors a maximum return.” This integrated system, con- sisting of central inverters of the VC series, a high- power medium-voltage transformer and a monitoring system, reaches a system efficiency of over 98 %, according to Lapczyna. A medium-voltage switchgear can be optionally integrated ex works. The central inverters of the VC series follow a completely new concept that makes the use of a com- biner box redundant since the DC circuit breakers are already integrated. This is expected to save costs and Reference plant in Roeselare, Belgium, with two reduce planning and installation effort significantly. Fronius central inverters of the type Agilo A grounding kit is integrated for use with thin-film Photos: Fronius International 36 Sun & Wind Energy 4/2013 New central inverters up to 1 MW www.ingeteam.com At Ingeteam, we apply the concept i+c, in every project that we undertake –innovation to find the best solution and commitment to provide the best service. Ingeteam’s new INGECON SUN PowerMax central inverters are now more powerful and efficient than ever: • Wider output power range: 275 to 1,019 kW. • Up to 98.8% maximum efficiency level. • DCAC integrated connection cabinet to facilitate the maintenance. • Available in Indoor and Outdoor versions. The formula of the new energy Visit us at: Johannesburg POWER & ELECTRICITY WORLD 9-10 April Istanbul SOLAREX 11-13 April Milan SOLAR EXPO 8-10 May Shanghai SNEC PV POWER EXPO 14-16 May Munich INTERSOLAR 19-21 June Delhi RENEWABLE ENERGY INDIA 12-14 Sept. Chicago SOLAR POWER INTERNATIONAL 21-24 Oct. READY FOR YOUR CHALLENGES Sun & Wind EnergyAvda. 4/2013 Ciudad de la Innovación, 13 - E-31621 Sarriguren - Spain - Tel. +34 948 288 000 - [email protected] 37 sun_wind_energy_210x297.indd 1 05/03/13 13:26 PHOTOVOLTAICS CENTRAL INVERTERS transport, simple installation and easy maintenance load ranges; thanks to a large heat sink, only small are the key features.” This is how Andrea Schartner, fans with low consumption are needed.