Study on Transient Stability of Power System Containing Non-Synchronous Machine Sources Based on PSCAD/EMTDC

With the significant increase in the proportion of non-fossil energy in primary energy, a large number of nonsynchronous machine sources (N-SMSs) are connected to the AC system through power electronic converters, which has broken the dominant position of synchronous machine sources (SMSs) in the power system, making the originally complex power system stability become more complicated. In view of the transient stability of power system containing N-SMSs, based on PSCAD/EMTDC, this paper analyzes the trend of critical clearing time varied with four influence factors by gradually replacing the SMSs with the equal-capacity N-SMSs in the two-area four-machine system. The influence factors include the proportion, the control modes, the position connected to the power system of N-SMSs, and the AC faults location. The simulation results show that as the proportion of N-SMSs increases, the transient stability is gradually enhanced; when the proportion of N-SMSs in the system is the same, compared to the centralized connection, the decentralized connection of N-SMSs can enhance the transient stability of two areas; when the power system dominated by N-SMSs suffers a AC fault, the transient response is fast and the fault recovery time is short.