基于超高频法的局部放电定位初步研究

Study of PD Location Based on the UHF Method

为了快速准确地对局部放电源定位,从而迅速排除故障、保障电力系统的正常运行,笔者描述了基于到达时间差定位的原理,并分析了影响定位精度的因素,即时差测量、局放源相对于各个接收天线的位置以及传播速度v等的影响。介绍了以信号初始峰、累积能量曲线的拐点、基本相关性以及三次样条插值和相关性相结合的方法为基准读取时间差的4种方法,通过比较分析得出利用三次样条插值和相关性相结合的方法为基准读取的时间差最接近理论时差。最后利用模拟退火法计算出了放电源的位置,实现了对单一局放源的定位。

In order to rapidly and accurately locate partial discharge source for getting rid of trouble and protecting normal operation of the power system, the principle of PD source location based on the time delay of arrival is discussed. The influencing factors of location accuracy are analyzed, including TDOA, the distances between PD source and sensors, and the velocity of electromagnetic waves. Four methods for acquiring TDOA are introduced and compared, including the initial peak method, the inflexion of cumulative energy curve method, the basic correlation method, and the method combining interpolation of cubic spline with correlation analysis. The results show that the last method can achieve high precision. At last, the location of PD source is calculated using simulated annealing algorithm.