The smarter E 2018

•••8••• Innovationen ThesmarterEEurope Modular battery inverter Fraunhofer ISE tests novel hybrid energy storage system T ogether with partners, re- searchers at the Fraunhofer Institute for Solar Energy Systems ISE have set up a novel hybrid en- ergy storage system on Borkum, an island on the North Sea. The system consists of a lithium ion battery and a super capacitor for short term power demands. The hybrid storage is connected to the medium voltage grid with a new type of modular inverter. During the field test lasting one year, the researchers will test and compare the different control strategies in the energy management system. In the EU project “NETfficient”, the electricity grid on Borkum is- land is supplied to a large extent by locally produced renewable energy and equipped with diverse storage technologies. The solu- tions for energy autonomy devel- oped in this project are tested un- der real conditions on the island and can be easily transferred to other regions later on. Distributed around the island, the storage sys- tems and suppliers are connected in a smart grid and controlled by an intelligent energy and grid management system. In all, forty home storage systems, five busi- ness systems, a thermal storage system and a new hybrid energy storage system are integrated in- to the medium voltage grid. “Be- sides the 500 kWh Li-ion battery, one of the most important com- ponents in the hybrid system is the battery inverter developed at Fraunhofer ISE,” remarks Dr. Olivi- er Stalter, Director of the Business Division “Power Electronics, Grids and Intelligent Systems” at Fraun- hofer ISE. “This inverter has a to- tal power of one megawatt con- taining up to eight highly compact and particularly dynamic subcom- ponents each with a power of 125 kW. The modularity enables sys- tems of any size up to the multi- megawatt range to be realized.” In addition to the Li-ion battery storage, a super capacitor is inte- grated into the system as short- term storage to smooth out pow- er peaks and thus increase the battery lifetime. “Due to its much higher switching frequency, the battery inverter developed at Fraunhofer ISE can respond more quickly to fluctuations in the elec- tricity grid than devices that are currently available. It is therefore suitable for a very fast primary reserve, for reducing peak loads as well as for self-consumption solutions on the industry scale,” explains Stefan Schönberger, Team Head at Fraunhofer ISE. The inverter plug-in unit is on display at Intersolar Europe in Munich (Stand A1.540). The modular battery inverter can be used for industrial pur- poses between 125 and 2000 kilowatt. Photo: Fraunhofer ISE Anzeige Ferroamp PowerShare technology The EnergyHub system consists of a scalable bidirectional inverter and DC/DC converters designed for specific applications. These components form a local DC mi- crogrid that integrates PV solar, energy storage and EV charging into one system. This eliminates the need for separate inverters and rectifiers for PV production and batteries. The PowerShare technology takes the EnergyHub advantages to a new level. By connecting the 760 VDC nanogrid between buildings equipped with local bidirectional inverters, the combined PV solar production can be shared by feed- ing power to each building, thus sharing the load profile to maxi- mize self-consumption. In addi- tion to sharing PV production, the technology can also be used to share a central energy storage among multiple users thus bring- ing a significant increase in PV self consumption and a more cost effective use of batteries. Further, load peaks at one user, for example from EV charging, can be distrib- uted among other users to reduce peak load drawn from the public AC grid. +JWWTFRU *QJPYWTSNP &' )TRSFW[XLFYFS 8U©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