Generalized Short Circuit Ratio Calculation Based on Thevenin Equivalent Parameters Identified through Transient Simulation

Generalized short circuit ratio (gSCR) can be used to efficiently measure the strength of receiving end AC system, which is the foundation of secure operation of HVDC. A gSCR calculation method based on Thevenin equivalent parameters identified through transient simulation is proposed, which simplifies the receiving end AC system with multi-port Thevenin equivalent model, identifies the equivalent parameters through transient simulation data after fault clearance, and calculates the gSCR based on the identified parameters. The proposed method has the advantage of considering the effect of generator transient reactance, and hence improves the accuracy of the gSCR calculation. Case studies from single-infeed and four-infeed HVDC system show that the proposed method is feasible and effective with good accuracy and robustness.