Study on the Influence Mechanism of Virtual Synchronous Compensator on the Transient Synchronous Stability of New Energy in Weak Power Grids

By combining virtual synchronous machine control into the static var generator (SVG), the virtual synchronous compensator (VSCOM) can achieve active support of the grid voltage and improve the weak grid adaptability of the SVG. However, the interaction characteristics of VSCOM based on grid forming control as a reactive power compensator with renewable energy grid-connected converter (REGC) using grid following control are more complicated. Therefore, this paper aims to investigate the effect of VSCOM on the transient synchronization stability of REGC during large disturbances in the grid. Firstly, the constant voltage current limiting control of VSCOM is proposed based on its characteristics. Secondly, a mathematical model is established based on this control to analyze the improvement effect of VSCOM on the static stability limit of REGC. Then, by constructing the transient model of VSCOM and REGC, the mechanism of the effect of VSCOM on the transient synchronization stability of REGC is investigated by considering the short circuit ratio, control parameters, and reactive power capacity. Finally, an electromagnetic transient simulation model is constructed based on the MATLAB/Simulink platform to verify the correctness of the theoretical analysis in this paper.