Fast coordinated power control for improving inertial and voltage support capability of battery energy storage systems

This paper proposes a fast coordinated power control method based on two augmented channels (AC) in battery energy storage system (BESS) to improve its inertial and voltage support capability, i.e., a frequency-reactive power channel (FRPC) and a voltage-real power channel (VRPC). For the frequency control, in the power distribution system with high resistance/inductance ratio, the coupling mechanism between rate of change of frequency (RoCoF) and required reactive power (RRP) of grids is analyzed, indicating that RoCoF is proportional to the RRP. Thus, RoCoF is utilized in the FRPC to generate reactive power for the complementary inertial emulating control. Meanwhile, for the voltage control, the coupling characteristics between rate of change of voltage (RoCoV) and demanding real power (DRP) of grids is also studied, revealing that RoCoV is proportional to the DRP. Therefore, it can be adopted in VRPC to generate real power for complementary voltage control. Then, the grid-voltage-modulated direct power control is selected as the inner power control loop to track the power references with faster dynamic performance comparing with traditional vector-oriented control. Finally, simulations and hardware-in-loop experiments validate the improvement in performance of grid frequency and voltage control based on the proposed method.