基于有功前馈补偿的储能VSG并网有功振荡抑制策略

为解决传统储能虚拟同步机(virtual synchronous generator, VSG)的并网有功由于其一次调频系数与虚拟阻尼系数相互耦合而存在稳态偏差与动态振荡难以兼顾的问题，提出一种基于有功前馈补偿的储能VSG并网有功动态振荡抑制策略。该策略利用有功经一阶低通滤波器后前馈至并网有功闭环控制回路，通过调节前馈系数优化储能VSG并网有功的动态性能且无需进行微分运算，同时不影响储能VSG的一次调频特性。然后，建立基于有功前馈补偿的储能VSG并网有功闭环的小信号模型，并给出前馈系数的整定方法。最后，利用仿真与实验测试对比结果共同验证了所述策略在有功指令与电网频率2种阶跃扰动下可有效消除储能VSG并网有功的稳态偏差及其动态振荡，且不存在频率过冲的风险。

Grid-connected active power oscillation suppression strategy of an energy storage VSG based on active power feed-forward compensation

In a traditional energy storage virtual synchronous generator (VSG) with grid-connected active power (GCAP) it is difficult to balance the steady-state deviation and dynamic oscillation, because of the coupling of its primary frequency modulation coefficient and virtual damping coefficient. Thus a GCAP dynamic oscillation suppression strategy for an energy storage VSG based on active power feed-forward compensation is proposed. The active power is fed-forward to the GCAP closed control loop through the first-order low-pass filter, and the GCAP dynamic performance for energy storage VSG is optimized by adjusting the feed-forward parameter without using the differential operation. The VSG primary frequency modulation characteristic is not affected. Then a small signal model of GCAP closed-loop for the energy storage VSG based on active power feed-forward compensation is established, and the setting method of the feed-forward coefficient is given. Finally, comparison of simulation and experimental test is used to verify that the proposed strategy can effectively eliminate the steady-state deviation, and dynamic oscillation of GCAP of the energy storage VSG under two-step disturbances of active power command as well as grid frequency, and there is no risk of frequency overshoot.