Virtual Synchronous Generator Dynamic Decoupling Technology Based on Complex Vector Current Controller

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.