The concept of virtual synchronous generators (VSGs) is an effective means for improving the stable operation of the grid when the large number of distributed power sources connected to the grid. However, due to its power coupling problem, coupling overshoot and steady-state error occur during power adjustment, which seriously affects the dynamic performance and stability of the system. With this problem in mind, the system model of VSG is established by using a complex vector analysis method. Then the coupling system is analyzed by the bilateral frequency response characteristic curve and pole-zero diagram. On this basis, a dynamic decoupling method based on complex vectors is proposed. Decoupling is obtained by eliminating the poles of the controlled object through the zero points of the controller. After decoupling, when the system performs active power adjustment, the reactive power coupling overshoot is reduced by 83% and the steady-state error is completely eliminated. When the system performs reactive power adjustment, the active power coupling overshoot is reduced by 80%, the dynamic performance and stability of the system have been improved. Simulation and experimental is used to verify the theoretical analysis.

当大量分布式电源连接到电网时，虚拟同步发电机（VSG）的概念是提高电网稳定运行的有效手段。但是，由于其功率耦合问题，在功率调整期间会发生耦合过冲和稳态误差，这严重影响了系统的动态性能和稳定性。考虑到这个问题，通过使用复杂的矢量分析方法建立了VSG的系统模型。然后通过双边频率响应特性曲线和零极点图分析耦合系统。在此基础上，提出了一种基于复矢量的动态解耦方法。通过通过控制器的零点消除受控对象的极点来实现去耦。解耦后，当系统执行有功功率调整时，无功功率耦合过冲减少了83％，并且稳态误差被完全消除。当系统执行无功功率调整时，有功功率耦合过冲减少了80％，系统的动态性能和稳定性得到了改善。仿真和实验用于验证理论分析。