基于放电紫外成像特征的污秽线路盘形绝缘子绝缘状态评估

绝缘子是电网主要电气设备之一。绝缘子污秽闪络严重威胁电力系统的安全稳定运行,及时掌握污秽绝缘子的绝缘状态意义重大。文中从绝缘子放电紫外视频中进行帧提取,对提取的图像进行紫外光斑分割,计算得到光斑面积及其时间序列,并分析其与不同放电阶段泄漏电流之间的关联关系,给出绝缘子的绝缘状态并进行闪络预警。构建了湿度连续可调的人工雾室,利用紫外成像仪记录了盘形线路绝缘子污秽放电视频,提取其放电的紫外特征,结合肉眼观察、放电电流信号及相关参数,将绝缘子的绝缘状态划分为:"正常"、"一般"、"较差"和"很差"。提取了光斑面积序列的算术平均值、最大值、标准差和放电频度4个特征参数,对样本数据进行了聚类分析。工程实际应用表明了光斑面积序列对绝缘子的绝缘状态评估的有效性。

Insulation Condition Evaluation of Contaminated Disc Insulator for Transmission Lines Based on the Characteristic of Discharge UV Imaging Characteristics

Insulator is one of the main electrical equipment in power grid.Pollution flashover of insulators seriously threatens the safety and stability of power system.It is of great significance to mater the insulation status of polluted insulators timely.In this paper,the frame is extracted from the ultraviolet video of insulator discharge,the extracted image is segmented by ultraviolet spot,the of spot region area and its time series are calculated,and the relationship between the spot area and leakage current in different discharge stages is analyzed,based on which the insulating state of insulator is given and flashover warning is carried out.An artificial fog chamber with continuously adjustable humidity was constructed.Video of discharging contamination of disc insulators was recorded by UV imager.The ultraviolet characteristics of discharging were extracted.Combining with naked eye observation,leakage current signal and other related parameters,the insulating state of insulators was divided into four stages:"safe","warning","alarm"and"dangerous".The arithmetic mean,maximum,standard deviation and discharge frequency of the spot area sequence were extracted,and the sample data were analyzed and clustered.The practical application of the project shows that the spot area sequence is effective for the insulation condition assessment of insulators.