高压直流偏磁对变压器的影响及抑制方法研究

Study on the influence and suppression measures of HVDC bias to transformer

宁东±660 kV直流输电工程在单极大地方式下会使接地极附近的变压器产生直流偏磁现象,直流偏磁是变压器的一种非正常工作状态,严重时可危及电网的安全运行.以串联电容法为技术基础的变压器中性点直流电流隔离接地装置的研制与开发,合理运用了氧化锌阀组和大容量快速开关作为电容器的双重保护,可以有效地阻断变压器中性点直流电流的流入,避免变压器直流偏磁显现的发生,保证了电网安全稳定运行.

Ningdong ± 660 kV high voltage direct current transmission projects under way will enable grounding transformer DC magnetic biasing phenomenon very near.DC bias is a type of transformer＇s abnormal operating state,which can endanger the safe operation of power grid.The research and development of technology of in-line capacitance method for direct current isolation transformer neutral point grounding device applied of ZnO valve block and large capacity fast-switched capacitor dual protection,which effectively blocking DC current of transformer neutral point inflows,avoiding the occurrence of transformer DC magnetic biasing appeared,ensuring stable operation of power system security.