天堂抽水蓄能电站发电电动机中性点接地装置研制

Research & production of the generator neutral point earth device of Tiantang Pump-storage Power Station

湖北天堂抽水蓄能电站发电机中性点采用带二次负载电阻配电变压器的接地方式。当机组发生单相接地短路故障时,接地装置通过电阻损耗功率对电容性无功功率的补偿,将暂态过电压限制在机组绝缘允许范围内,同时在接地保护配合下,经短延时切除机组,可避免机组在故障状态下继续运行而导致事故扩大。该装置于2001年投入电网运行,迄今工作稳定、正常,收到了预期效果。

The generator neutral point of Hubei Tiantang Pump-storage Power Station adopts the earthing scheme through distribution voltage transformer witb secondary load resistance. When the single-phase earth trouble of shorting out takes place to the generating set, the earth device confines the transient overvoltage in the allowable insulation range of the set through the compensation of the power loss that the resistance produces to the capacitive wattles power, and switches off the generating set after delaying short time in cooperation with earth protection, prevent the generating set from continuing operate but causes the accident to expand under the trouble state. This paper narrates the operation principle, device configuration, and integration research situation of the equipment briefly.