Improved VSG Transient Damping Strategy for Improving Grid Voltage Support Capability

Aiming at the problem of active power dynamic oscillation and steady-state deviation under the condition of active power command and grid frequency disturbance when the energy storage virtual synchronous machine is connected to the grid, a transient damping optimization strategy based on active power differential feedback is proposed. Firstly, the control principle of VSG is given, and the closed-loop small signal model of VSG under active power command and grid frequency disturbance is established. The influence of damping coefficient on dynamic oscillation and steady-state deviation of output active power is analyzed. On this basis, an improved transient damping strategy based on active power differential feedback is proposed and its parameter design method is given. Finally, the effectiveness and superiority of the proposed damping optimization strategy in suppressing active power dynamic oscillation and eliminating steady-state deviation are verified by simulation.