DQ impedance modeling and stability analysis of virtual synchronous generator considering voltage current loop

Abstract

In practical application, the voltage and current loop of virtual synchronous generator (VSG) usually adopt PI controller in rotating coordinate system, so its parameters play a significant part on the system stability. Therefore, we leveraged the $\boldsymbol{dq}$ impedance modeling method and established the model of VSG, which factors in the effect of the voltage and current loop. Then, according to the established model, the influence of parameters on the $\boldsymbol{dq}$ impedance of VSG and the system stability are analyzed. The theoretical analysis shows that the decrease of the proportional coefficient and the increase of the integral coefficient of the voltage controller, and the decrease of the proportional coefficient of the current controller reduces the system stability; the integral coefficient of the current controller has little effect on the system stability. Finally, the 10kW VSG simulation model is built to verify the theoretical analysis.