南方电网中直流紧急功率调制的作用

采用NETOMAC数字仿真的方法 ,分析了南方电网中 3条直流输电线路间的紧急功率支援 ,包括贵广直流双极闭锁等故障时天广和三广直流紧急功率提升的作用 ,以及三广直流双极闭锁等故障时天广和贵广直流紧急功率提升的作用。揭示了逆变站电压支撑不足是限制直流功率紧急提升充分发挥作用的主要因素。研究结果表明 ,天广直流紧急功率提升对贵广直流双极闭锁时保持系统稳定性的效果非常好 ,而三广直流紧急功率提升对贵广直流双极闭锁时系统稳定性的作用不明显 ;博罗—横沥 1回线三相短路 0 .1s跳双回时 ,若无直流紧急功率提升 ,则系统将失稳 ;若天广或贵广直流中任意 1回紧急功率提升投入 ,则系统都能稳定 ,其中以贵广直流紧急功率提升投入效果较好 ;而若 2回直流紧急功率提升同时投入 ,则其效果不如贵广直流紧急功率提升单独投入好。

Effect of HVDC Emergent Power Modulation in South China Power System

In this paper, the mutual emergent power support among the three HVDC links in South China power system is studied with NETOMAC. The studied schemes include the emergent power modulation of Tian-Guang HVDC link or San-Guang HVDC link when Gui-Guang HVDC link is double pole blocked, and the emergent power modulation of Tian-Guang HVDC link and Gui-Guang HVDC link when San-Guang HVDC link is double pole blocked. The study reveals that the voltage support in the inverter is the main limiting factor for the effectiveness of the HVDC emergent power modulation. The results also show that the emergent power increase in Tian-Guang HVDC is more effective than that in San-Guang HVDC for the stability of the system when Gui-Guang HVDC is double pole blocked. When San-Guang HVDC is double pole blocked because of Buluo-Hengli double circuit tripping, the system will lose stability. In this situation, if Tian-Guang HVDC or Gui-Guang HVDC emergent power increase is activated, the system can be saved. And the emergent power increase in Gui-Guang HVDC is more effective than that in Tian-Guang HVDC. But the simultaneous power increase in Tian-Guang HVDC and Gui-Guang HVDC is less effective than only the power increase in Gui-Guang HVDC.