特高压直流单12脉动阀组的投退策略及其对交流系统无功冲击的影响

随着向家坝—上海±800 kV特高压直流输电工程的逐渐开展，研究了±800 kV特高压直流系统单12脉动阀组的投退策略，并比较了采取2种不同的策略投退单12脉动阀组时对交流系统的无功冲击。EMTDC仿真分析结果证实了这2种策略均能完成单12脉动阀组的正常投退，但不同的策略对交流系统的无功冲击不同，单12脉动阀组投退过程中直流电流保持4 000 A不变的策略对交流系统的无功冲击较高，另外一种先降低电流指令、投退单12脉动阀组，再恢复电流指令的策略对交流系统的无功冲击较低。

Influence of Blocking and Deblocking Strategies of Single 12-Pulse Converter Group for UHVDC Power Transmission on Reactive Power Impact to AC Power Grid

Based on gradual progress of ±800kV UHVDC project from Xiangjiaba to Shanghai, the blocking and deblocking strategy of single 12-pulse converter group of this project are researched and the reactive power impact on UHVAC power grid caused by two different blocking and deblocking strategies is researched. Simulation results by EMTDC confirm that the two strategies can perform normal blocking and deblocking of single 12-pulse converter group, but different strategy causes different reactive power impact on UHVAC power grid. The strategy, in which the DC current is hold in the level of 4000A during the blocking and deblocking process, causes stronger impact on UHVAC power grid; and the other one, in which firstly the current reference is decreased, then the blocking and deblocking of single 12-pulse converter group is performed, finally the current reference is restored, causes lower reactive power impact on UHVAC power grid.