A Quick Criterion on Judging Short-Term Large-Disturbance Voltage Stability Considering Dynamic Characteristic of Induction Motor Loads

Short-term large-disturbance voltage instability is an increasing industry concern. A common scenario is a large disturbance such as a multi-phase fault near a load center that decelerates motor loads. Following fault clearing with transmission outages, motors draw very high current while simultaneously attempting to reaccelerate, and may stall if the power system is weak. Massive loss of load and possibly area instability and voltage collapse may follow. Here Short-term large-disturbance voltage stability is analyzed considering electromechanical transient model of induction motor. A criterion serving to quickly judge power system short-term large- disturbance voltage stability is presented considering electromechanical transient procedure of induction motor after large disturbance. The accuracy of this criterion is improved in comparison with the existing criterion. It can give quick judgment on short-term large-disturbance voltage stability and effectively reduce the amount of calculation for simulation analysis. It is expected to be used in the on-line environment in the future. The correctness of this criterion is verified by time domain simulation results.