±1100kV特高压换流站直流操作过电压研究

DC switching overvoltage of ±1100 kV UHVDC converter station

基于准东—四川±1100 kV特高压直流输电工程,详细分析了特高压直流换流站阀厅和直流场的操作过电压机理,并仿真计算了高压端Y/Y换流变阀侧绕组接地、低压端Y/Y换流变阀侧绕组接地、交流侧相间操作冲击、逆变侧失交流电源、全电压起动和逆变侧闭锁而旁通对未解锁等故障在换流站设备上产生的过电压值,给出了准东换流站相应避雷器承受的最大过电压和能量。计算结果可为该特高压工程换流站设备的绝缘配合及相关设备选型、试验提供重要依据。

The mechanism of switching overvoltage occurred in the valve hall and DC switchyard of±1100 kV UHVDC converter station is analyzed based on Zhundong-Sichuan± 1 100 kV UHVDC power transmission project. Different faults are simulated,such as the grounding fault of HV winding of Y/Y converter transformer at valve side ,the grounding fault of LV winding of Y/Y converter transformer at valve side,the phase-to-phase switching surge at AC side,the AC power loss at inverter side,the full-voltage starting,the inverter blocking without by-pass de-blocking,and the corresponding overvohages exerted on the equipments of converter station are calculated,which provide the reference for the type selection,test and insulation coordination of station equipments.