交流电网整流变引起的直流偏磁机理与实验分析

The Mechansim and Experiment Analysis of DC Magnetic Bias Caused by Rectifier Transformer of AC Grid

电力变压器中出现直流偏磁现象不容忽视,根据没有直流输电线路的重庆电网出现直流偏磁现象的情况,结合重庆地区供电格局、负载情况,针对该直流偏磁引起的原因进行了研究。分析了整流变压器在工作过程中因换流阀触发不平衡,交流侧正序二次谐波等原因产生直流并流入电网,对电网中其他变电站造成直流偏磁的影响。采用相应措施,针对变压器的直流偏磁进行实测,论证了整流变压器对交流电网产生直流偏磁影响的现象,并获得其主要特征。

In power transformer, DC magnetic bias cannot be ignored. According to the situation of DC magnetic bias in Chongqing electric power network, the reason of DC magnetic bias is studied. Analysis of the rectifier transformer in working process due to commutation valve trigger the unbalance, AC side of the second harmonic voltage of positive sequence and produces a DC and flow into the power grid, to power in the substation caused by the influence of DC biasing. Using the corresponding measures, the DC magnetic bias of the transformer is measured and the effect of the rectifier transformer on the DC magnetic bias is demonstrated.