This paper analyzes the transient angle stability between synchronous generators(SGs)and grid-forming voltage source converters(GFM-VSCs),considering backward-swing dynamics.The impact mechanism of current saturation ...This paper analyzes the transient angle stability between synchronous generators(SGs)and grid-forming voltage source converters(GFM-VSCs),considering backward-swing dynamics.The impact mechanism of current saturation control(CSC)on the backward-swing and forward-swing stability is addressed.Based on the second-order rotor motion equation,the conventional energy-based method for transient stability evaluation becomes rough driven by the interactions between SG and GFM-VSC.To overcome the barrier,a forward-time integral(FTI)method is proposed for calculating the critical clearing time(CCT).We discover that the CSC can affect the stable and unstable equilibrium points of the post-fault system,leading to both the backward-swing and forward-swing synchronism instability.Based on the mechanism,an enhanced synchronization control(ESC)is proposed.It combines a modified frequency control with a current-limit strategy to avoid backward-swing instability while enhancing forward-swing stability.Time-domain simulation verifies the theoretical analysis as well as the effectiveness and robustness of the proposed ESC.展开更多
基金supported in part by the National Natural Science Foundation of China under Grants U23B6008。
文摘This paper analyzes the transient angle stability between synchronous generators(SGs)and grid-forming voltage source converters(GFM-VSCs),considering backward-swing dynamics.The impact mechanism of current saturation control(CSC)on the backward-swing and forward-swing stability is addressed.Based on the second-order rotor motion equation,the conventional energy-based method for transient stability evaluation becomes rough driven by the interactions between SG and GFM-VSC.To overcome the barrier,a forward-time integral(FTI)method is proposed for calculating the critical clearing time(CCT).We discover that the CSC can affect the stable and unstable equilibrium points of the post-fault system,leading to both the backward-swing and forward-swing synchronism instability.Based on the mechanism,an enhanced synchronization control(ESC)is proposed.It combines a modified frequency control with a current-limit strategy to avoid backward-swing instability while enhancing forward-swing stability.Time-domain simulation verifies the theoretical analysis as well as the effectiveness and robustness of the proposed ESC.
