基于带通阻尼功率反馈的虚拟同步发电机控制策略

Damping power feedback is used in virtual synchronous generator (VSG) to restrain power oscillation caused by the virtual inertia of the active power control loop. The traditional damping power feedback strategy with PLL included depends on the measurement of the grid voltage phase, which acts against the control object that VSG makes grid-tied inverter to be a self-synchronizing independent voltage source. The traditional damping power feedback method without PLL included essentially merges the droop control and damping feedback into only one droop control, thus the VSG would not meet the requirements of power oscillation damping and primary frequency regulation of power system at the same time. To address this issue, this paper develops an improved VSG control strategy based on bandpass damping power feedback. The closed loop dynamic characteristics and parameters design process of the improved VSG strategy are also presented. The proposed strategy can remove the effect of damping power feedback channel on the droop control, as a result the primary frequency control and active power allocation performance of VSG can be ensured. Finally, both the simulation and experimental results prove the effectiveness of the proposed method.