一起换流站极母线直流电压测量异常原因分析

Analysis About Abnormal Pole Bus Direct Current Voltage Measurement in Convertor Station

针对±500kV桂中换流站双极先后出现极母线直流电压测量异常的情况,从测量异常现象入手结合直流电压测量装置原理,依据现场检查结果初步确定了故障位置。通过现场复现式仿真实验,确定了故障原因为远端模块箱体接地不良造成其前级电路的电阻一端浮空,通过在远端模块箱体增加屏蔽接地线等方法,消除了测量异常。

Aiming at the abnormal high fault condition of bus voltage UdL happened one after another in±500kV Guizhong ConverterStation’s twin poles,starting from abnormal measurement and combining with the principle of direct current voltage measuring device,thispaper preliminarily confirmed the fault location according to the onsite inspection results.The onsite reproduction simulation experimentsshow that the imperfect grounding of remote terminal unit box caused one end earth free of its preceding stage circuit resistance.The way toadd shielding grounding etc.for remote terminal unit box could eliminate abnormal measurement.