Research on medium voltage battery energy storage system based on RT-LAB

The renewable energy resources produce fluctuating power and impair the stability of the grid. One solution is to integrate battery energy storage system (BESS) into the grid to smooth the power. As the power of the renewable energy resources and the capacity of microgrid is increasing, high power BESS connected to medium voltage grid is needed. This paper studies a 10kV-2MW transformer-less BESS based on cascaded H Bridge topology, and design its power control system and state of charge (SOC) balance control system. The control system is then implemented in the Matlab/Simulink and real time simulation system RT-LAB. The simulation results verify the validity of the control method, and indicate that compared with Matlab simulation, the real time RT-LAB simulation can get correct results even though the simulation time step is much larger.