Bi-directional power control of grid-tied battery energy storage system operating in frequency regulation

This paper presents a design of an average value PWM voltage source converter (VSC) along with bi-directional active and reactive power flow control in a grid-tied battery energy storage system. A vector control strategy with PI controllers is proposed. In this paper, a grid frequency regulation control design is also implemented in the BESS in order to meet the frequency response requirement by the National Grid Electricity Transmission, the primary distribution network operator in the UK. Simulation results on a 2MW/968kWh lithium-ion BESS are provided to verify the proposed control design based on the control of an experimentally validated battery model