基于正则化的变电站局部放电定位方法

A Partial Discharge Location Method in Substations Based on Regularization

基于特高频传感器阵列的变电站局部放电检测与定位方法得到应用,但获取多传感器到达时间差不可避免地存在误差,导致非线性定位方程组的解误差较大。提出基于正则化的变电站局部放电定位方法,为避免直接求解非线性定位方程组导致定位误差大、计算复杂等问题,通过消除二阶项,将非线性定位方程组转换为线性定位方程组。针对由传感器安装位置可能引起线性定位方程组存在病态问题,通过中心化法和平衡法对方程组处理,降低了方程组病态程度,用L曲线法计算正则化参数,最后使用Tikhonov正则化方法求解线性定位方程组,确定局部放电源坐标。仿真与模拟实验表明,到达时间差误差为3%～5%时,定位误差为1.58m;到达时间差误差为7%～10%时,定位误差为3.07m。在一定时间差误差下,正则化方法能够提高局部放电定位精度,实现变电站局部放电的精确定位。

The detection and location of partial discharge(PD)using ultra-high frequency(UHF)sensor array was applied in substations.However,the error of obtaining the time of arrival of multi-sensors is inevitable,which leads to a large error in solving the nonlinear location equations.In this paper,a PD location method in substations based on regularization was proposed.In order to avoid solving the nonlinear location equations directly,which leads to large location error and complex calculation,the nonlinear location equations were transformed into the linear location equations by eliminating the second order terms.As for the morbid problem of the linear location equations caused by the sensor installation position,the equations were processed by the centralization method and the balance method to reduce the morbidity of the equations.The regularization parameters were calculated by the L-curve method.Finally,the linear location equations were solved by using the Tikhonov regularization method to determine the coordinates of the PD source.Simulations and simulation experiments show that the location error is 1.58 m when the time-difference error is 3%~5%,and the location error is 3.07 m when the time-difference error is 7%~10%.The regularization method can improve the precision of partial discharge location and realize the accurate location of partial discharge in substations under certain time difference errors.