中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2011年
22期
88-95
,共8页
电力系统%交流故障%高压直流%换流站%阀短路保护%桥差保护
電力繫統%交流故障%高壓直流%換流站%閥短路保護%橋差保護
전력계통%교류고장%고압직류%환류참%벌단로보호%교차보호
power systems%AC fault%high voltage direct current （HVDC）%converter stations%valve short protections%bridge differential protections
换流站内发生的交流系统故障会对交直流系统产生严重的危害。通过对换流阀换相电压的特性分析指出：站内发生交流接地时会伴随桥臂短路及交流系统复故障的出现；相间故障则表现为不平衡换相。通过接地故障发生后换流阀的电流时间函数来说明故障电流呈现交流多相短路的特征。通过故障等效交流电路来研究交直流保护特性，并得出结论：对于接地故障，电流互感器（current transformer，CT）安装在不同位置时，阀短路保护、桥差保护均能正确动作；但发生相间故障时，却会造成某些工况下保护不能动作；在连接高端阀的交流系统接地时交流保护的距离元件有时会有超越现象。最后提出采用零序补偿分量的方法来提高启动元件的性能。CIGRE高压直流（high voltage direct current，HYDC）模型验证了分析结论。
換流站內髮生的交流繫統故障會對交直流繫統產生嚴重的危害。通過對換流閥換相電壓的特性分析指齣：站內髮生交流接地時會伴隨橋臂短路及交流繫統複故障的齣現；相間故障則錶現為不平衡換相。通過接地故障髮生後換流閥的電流時間函數來說明故障電流呈現交流多相短路的特徵。通過故障等效交流電路來研究交直流保護特性，併得齣結論：對于接地故障，電流互感器（current transformer，CT）安裝在不同位置時，閥短路保護、橋差保護均能正確動作；但髮生相間故障時，卻會造成某些工況下保護不能動作；在連接高耑閥的交流繫統接地時交流保護的距離元件有時會有超越現象。最後提齣採用零序補償分量的方法來提高啟動元件的性能。CIGRE高壓直流（high voltage direct current，HYDC）模型驗證瞭分析結論。
환류참내발생적교류계통고장회대교직류계통산생엄중적위해。통과대환류벌환상전압적특성분석지출：참내발생교류접지시회반수교비단로급교류계통복고장적출현；상간고장칙표현위불평형환상。통과접지고장발생후환류벌적전류시간함수래설명고장전류정현교류다상단로적특정。통과고장등효교류전로래연구교직류보호특성，병득출결론：대우접지고장，전류호감기（current transformer，CT）안장재불동위치시，벌단로보호、교차보호균능정학동작；단발생상간고장시，각회조성모사공황하보호불능동작；재련접고단벌적교류계통접지시교류보호적거리원건유시회유초월현상。최후제출채용령서보상분량적방법래제고계동원건적성능。CIGRE고압직류（high voltage direct current，HYDC）모형험증료분석결론。
It may cause severe damages to the AC and DC systems when the faults in the AC system of converter station occur. By analyzing the characteristics of the valve commutating voltage, it can be concluded that the ground fault at the converter station will cause short circuit across the bridges and multiple complex AC faults, and the line-to-line fault will result in unbalanced commutation. The fault current is characterized as AC short circuit among multiple phases and this can be illustrated by the time function of the commutating valve current after ground fault taking place. The paper analyzes AC and DC protections by the equivalent model of the AC fault circuit. It shows that for ground faults, the valve short circuit protection and bridge differential protection can operate correctly with different current transformer （CT） locations. However, under some operating conditions, the protection system may fail to operate for line-to-line faults. In addition, sometimes the distance components of AC relay have overreach phenomenon when a AC ground fault at the high-voltage side of the valves occurs. Finally, a method using zero-sequence compensation component, which can improve the performance of the startup component, was proposed. Application to the CIGRE high voltage direct current （HVDC） benchmark model verified the analytical results.
