用于局部放电信号定位的多样本能量相关搜索提取时间差算法

Time Difference Algorithm Based on Energy Relevant Search of Multi-sample Applied in PD Location

提出一种应用多样本非平稳信号的能量相关搜索提取时间差算法,阐明该算法的原理,给出具体计算公式和步骤,对实验室获得的大量变压器局部放电超高频信号数据样本,经过"相关–移位–叠加"数学变换,得到具有统计意义的能量累积曲线,再利用相关搜索原理准确计算出多传感器信号间的时间差,有效解决了多信号间时间差难以准确获取和用单样本数据对局放源定位的结果分散性大的问题,其定位时间误差在皮秒级,距离误差在厘米级。

A new time difference algorithm of multisample nonstationary signals is proposed in this paper, including its principle and formula, which uses the mathematical transformation of ＂relevant-shift-superposition＂ to obtain a statistical accumulated energy curve from a large amount of PD samples of transformer in laboratory. The time delay of multiple sensors by relevant search principle was obtained. This method has been used in PD measurement of transformer and proved to be effective to solve the problems of strong dispersiveness in PD location by single-sample signal as well as the difficulty to access time delay accurately, its time error is in the picosecend level and location error is in the centimetre level.