基于脉冲波形的交直流复合电压下油纸绝缘球板电极模型局放发展阶段评估

Development Stage Evaluation on Partial Discharge of Oil-paper Insulation in Ball-plate Electrode Model Under AC and DC Compound Voltage Based on Pulse Waveform

通过搭建球板电极的油纸绝缘实验平台,对单个局部放电波形的几何特征进行分析,构成最大幅值概率密度分布图、单个波形总时间概率密度分布图和最大幅值时间所占比例概率密度分布图。对每一个概率密度分布图提取平均值、方差、斜度和陡峭度4个特征量,然后利用K均值聚类算法进行聚类,对球板电极油纸绝缘的缺陷发展程度进行分类。结果表明:单个局部放电波形中各特征量的平均值与分散度随着油纸绝缘缺陷的发展具有明显不同,缺陷发展程度分为3个阶段,由此可以判断油纸绝缘的缺陷发展程度。

An oil-paper insulation experiment platform of ball-plate electrode was built and the geometric characteristics of single partial discharge waveform were analyzed to constitute the probability density distribution images of maximum amplitude, total time of single waveform, and ratio of maximum amplitude time. Four characteristic parameters including average value, variance, skewness, and steepness were extracted from each probability density distribution image, and then K-means clustering algorithm was used to cluster them so as to classify development degrees of oil-paper insulation defect. The results show that the average value and dispersion degree of each characteristic parameter in a single partial discharge waveform are obviously different with the development of oil-paper insulation defects, and the development degree of defect can be divided into three stages, which can be used to judge the development degree of oil-paper insulation defect.