【作者】 李伟；

【导师】 王胜辉；

【作者基本信息】 华北电力大学 ， 工程硕士（专业学位）， 2021， 硕士

【摘要】 绝缘子作为电力系统使用量最多的设备之一,其绝缘状态直接影响到电网的安全和稳定运行。目前对绝缘子检测的物理特征量较为单一,难以全面识别其缺陷和运行状态。基于此,本文提出了红外成像和紫外成像相互结合的联合检测方法,研究了不同因素下劣化瓷绝缘子和老化复合绝缘子的发热和放电问题,并对其典型缺陷的诊断问题开展了相关研究。定量分析了探测距离、温度、湿度、风速和气压对紫外成像量化参数的影响特性,得到了不同因素对紫外成像检测的影响关系曲线并进行了拟合分析,在此基础上提出了基于修正系数的归一化方法,修正后的相对误差低于20%,该方法实现了不同环境条件下检测结果的归一化,有助于不同因素下绝缘子缺陷诊断定量分析。搭建了基于人工气候室的悬式绝缘子检测试验平台,利用Flir T450SC红外热像仪和Coro CAM504紫外成像仪,研究了环境湿度、低零值绝缘子位置和等值附盐密度对110k V瓷绝缘子串的发热和放电特性的影响,分析了瓷绝缘子发热原因;分析了环境湿度、盐雾电导率和降雨强度对不同运行年限复合绝缘子放电和发热的影响,根据绝缘子上附着水珠的电场特性提出了两种简化的分析模型,研究了水珠体积、位置、电导率和相对介电常数对模型起晕和闪络电压的影响。基于绝缘子放电和发热特点,建立了绝缘子典型缺陷的红外和紫外特征参量数据库,并对紫外参数进行归一化处理。采用基于分类回归树算法的决策树诊断方法,以试验数据为训练样本,建立了绝缘子低零值和老化缺陷诊断模型,并基于Python开发了诊断系统,实现了对缺陷类型的评估诊断,并提出维修建议。更多还原

【Abstract】 Insulator is one of the most used devices in power system,and its insulation status directly affects the safety and stable operation of power grid.At present,the physical characteristic quantity of insulator detection is relatively single,so it is difficult to fully identify its defects and operation status.Based on this,this paper proposes a joint detection method of infrared imaging and ultraviolet imaging,studies the heating and discharge problems of deteriorated porcelain insulator and aging composite insulator under different factors,and carries out relevant research on the diagnosis of typical defects.The influence characteristics of detection distance,temperature,humidity,wind speed and air pressure on the quantitative parame ters of UV imaging are analyzed quantitatively.The influence curves of different factors on UV imaging detection are obtained and fitted.On this basis,a normalization method based on correction coefficient is proposed.The corrected relative error is le ss than 20%,This method realizes the normalization of test results under different environmental conditions,which is helpful to the quantitative analysis of insulator defect diagnosis under different factors.The test platform of suspension insulator det ection based on artificial climate chamber was built.The influence of environmental humidity,low zero insulator position and equivalent salt density on the heating and discharge characteristics of110 k V porcelain insulator string was studied by using Flir T450 SC infrared thermal imager and Coro CAM504 ultraviolet imager,and the heating reasons of porcelain insulator string were analyzed;The effects of environmental humidity,salt spray conductivity and rainfall intensity on the discharge and heating of co mposite insulators with different operating years were analyzed.According to the electric field characteristics of water droplets attached to insulators,two simplified analysis models were proposed.The effects of water droplet volume,position,conducti vity and relative permittivity on the corona inception and flashover voltage were studied.Based on the characteristics of insulator discharge and heating,the infrared and ultraviolet characteristic parameters database of typical insulator defects is established,and the ultraviolet parameters are normalized.Using the decision tree diagnosis method based on classification regression tree algorithm and taking the test data as the training sample,the diagnosis model of insulator low zero value and aging defects is established,and the diagnosis system is developed based on Python,which realizes the evaluation and diagnosis of defect type,and puts forward the maintenance suggestions.更多还原