直流换流站接地极对变压器中性点电流的影响

Impact of Earth Electrode of DC Inversion Station on Transformer Neutral Points

昭阳电厂在江城直流单极输电情况下,出现电厂主变压器异常振动的现象,同时监测到中性点直流高达59A。为此,对广东境内鹅城变电站的直流接地极进行分析,利用空间三维电磁场有限元仿真地中散流,得到目标电网的地表电势,通过简化广东220kV交流电网得到昭阳电厂主变压器中性点电流。最后,就中性点直流分量对变压器产生的影响进行评价。

There is abnormal vibration of main transformers in Shaoyang power plant and it is monitored that direct current at neutral point is as high as 59A under the circumstance of DC monopole transmission.Therefore,the paper analyzes DC earth electrode in E cheng.The 3D electromagnetic filed finite element is employed to simulate ground current for obtaining surface potential,and current in neutral point of main transformers in Shaoyang power plant is obtained by simplification of 220 kV AC power system.Finally,impact of DC component in neutral point on transformers is evaluated.