Participation of Energy Storage Batteries in Primary Frequency Control for Power Grid Considering Dynamic Frequency Inertia Characteristics

The inertial of the system and the maximum frequency deviation caused by the energy storage batteries when participating in grid frequency regulation need to be improved. Virtual synchronous generator control (VSG) for grid side converter is expected to improve the performance of storage battery energy participation in grid primary frequency regulation. Therefore, participation of energy storage batteries in primary frequency control for power grid is proposed considering dynamic frequency inertia characteristics. To utilize the inertial support and primary frequency regulation capability of the energy storage batteries for the grid, an additional active power module is constructed, and the active power generated by the virtual inertial control and droop control strategies of the energy storage batteries are used as additional power for variable rotor inertial control and output feedback model predictive control, respectively. For the mismatch between the inertia characteristics of the virtual synchronous machine and the grid demand, a variable rotor inertia control strategy considering system frequency deviation and system frequency change rate is designed to realize the real-time adjustment of rotor inertia to the system frequency. The output feedback model prediction control of VSG is further proposed to achieve dynamic prediction and compensation of system frequency deviation by establishing a feedback channel between rotor angular frequency increment and torque increment. A comparative analysis with three existing control strategies shows that the control strategy proposed can make full use of the frequency regulation capability of the energy storage battery and VSG to effectively reduce the frequency deviation and frequency variation rate of the grid.