基于多导体传输线模型的单相变压器绕组中放电的距离函数法定位

基于多导体传输线理论建立放电脉冲信号在大型单相变压器绕组中的传输模型.结合真实变压器绕组的具体结构,在频域仿真计算了绕组不同位置注入放电脉冲电流时其首末端的电流传输函数比曲线.根据绕组电流传输函数比曲线的可分性,采用距离函数法实现了变压器绕组中局部放电的电气定位.该方法根据实测与仿真传输函数之间的距离函数大小判断放电位置,180匝连续式单绕组和400kV单相变压器的模拟定位试验验证了该方法的有效性.

Distance Function Locating Partial Discharge in Single Phase Transformer Winding Based on MTL Model

Based on multi-conductor transmission line(MTL)theory, pulse propagation model of partial discharge in transformer winding is established. Together with the real winding structure, its sectional winding current transfer function ratio of HV terminal to earth terminal is calculated. When discharge pulses are injected in different locations, their transfer function ratio curves are different for each other, so that the method of distance function is presented to locate partial discharge in transformer winding. The distance of transfer function ratios between transformer testing and simulating results are calculated, then the location of PD is determined by the smallest value of distance function. Single winding and 400kV transformer winding test results show the validity of the method.