Transient voltage stability of Sichuan power gird is a problem caused by a serious malfunction when load center is simultaneously received from internal high power supply and external gird.In addition,HVDC feed-in will further deteriorate transient voltage stability of Sichuan power gird.Focus on this problem,an evaluation index of transient voltage stability is firstly proposed considering penalty function and operation mode of all nodes with all faults,which can automatically quantify the factors affecting the operation mode,and support the realization of automatic search and compilation reasonable bad operation mode.Secondly,the mechanism of transient voltage stability in Sichuan power gird is revealed,that is caused by large range surge of huge blocking power after AC failure occurred in the mode of power supply and load power consumption.The two root causes for decreasing transient voltage stability in Sichuan power gird are mainly analyzed,that is,the increasing of receiving ratio in load center caused by Deyang-Baoji HVDC feed-in operation and the weakening of dynamic voltage support capacity.Finally,the measures including optimizing HVDC control parameters are presented to improve the transient voltage stability of Sichuan power gird,which can provide a reference for the security and stability analysis of similar angle-voltage intertwined power grid.
sending-end power gridHVDC feed-inlarge capacity deliverytransient voltage stabilityquantitative evaluation indexvoltage dependent current order limiter(VDCOL)