The inverters charge the batteries from the electricity network and during subsequent discharge convert the direct current from the batteries to grid-compliant alternating current.
A broad DC voltage range, a highly developed control system and optimum adaptation to the different storage technologies allow lithium-ion, lead and other batteries to be used singly and in combination. In addition, the inverter systems have been designed specifically to provide a wide range of network system services and will ensure connection to the distribution network via medium-voltage transformers.
For the M5BAT project, SMA produced an innovative, modular, high-output battery inverter system that meets the new kinds of requirements for using battery storage in the grid.
Ten modular 630 kVA battery inverters are applied in the M5BAT pilot plant. All different battery lines are individually controlled by these inverters with a total power of 5MW. Two inverters can be combined in “twin-operation” for larger battery lines.
Innovative energy supply technologies such as wind and solar energy call for an intelligent, on-grid integration of storage systems in the megawatt category. SMA has met these requirements with special solutions and a new generation of battery inverters. The main focus areas of the associated research activities in the M5BAT project are as follows:
Firstly, all functionalities of the new battery inverter system will be tested in comprehensive laboratory tests. In subsequent M5BAT pilot operation, SMA will work with the other partners to evaluate operating strategies for the technical and economic optimisation of the battery inverter system, storage technologies and overall system. The use of the battery inverter system in the medium-voltage network will provide important insights into the configuration, safety and control technology of future systems and will at the same time demonstrate their operating behaviour and the costs involved.