大型变压器局部放电多目标定位实验

Experimental Study on Partial Discharges Localization Within Large Transformer

为了解决大型变压器内部局部放电源难以准确定位的问题,进行了以变压器内部同时存在多个放电源的定位为对象,通过传感器阵列接收放电源辐射的超声波信号,应用阵列信号处理技术中的空间谱估计理论,分析阵列传感器所接收信号的特征信息,实现局部放电的多目标定位的研究。研制了4阵元均匀等间隔线阵,建立了局部放电定位实验系统,针对单放电源和二个放电源的不同情况,对放电源空间位置进行了定位模拟实验。实验结果表明,该法具有良好的定位准确度,能有效地估计出变压器内多个放电点的空间位置,可实现电力变压器内部多局部放电源的定位,为变压器内多局放源的定位建立了实验研究基础。

In order to research and realize partial discharge （PD） sources localization within power transformer and to improve the accuracy of localization, a new method is presented in this paper, which is based On spatial spectrum estimation. Two ultrasonic sensor arrays are located on the inner wall of the transformer tank to detect the ultrasonic signal emitted by the partial discharge sources. Spatial spectrum estimation technique and information theoretic criteria are used in analyzing the signal feature information （Direction-of-Arrival （ DOA）, number of signal etc, and the number of partial discharge signal estimation and direction-of-arrival estimation were accomplished. A uniform linear array （ULA） consisting of 4 isotropic acoustic sensors was developed, a suit of experiment system for partial discharge sources localization testing system was established, and a series of experiments on multiple PD sources localization for single partial discharge source and two partial discharge sources were performed. The results of localization show that： the method can effectively estimate the location parameter of multiple partial discharge sources in a high estimated accuracy and set up solid theoretical and experimental foundation for multiple partial discharge sources localization in large power transformer.