In response to the problem of frequent leakage and false alarm of partial discharge insulation defects in GIS,this paper conducts experimental research on intermittent discharge characteristics of common solid insulat...In response to the problem of frequent leakage and false alarm of partial discharge insulation defects in GIS,this paper conducts experimental research on intermittent discharge characteristics of common solid insulation defects in GIS.Using true GIS to build amulti-source testing platform for intermittent discharge of solid insulation defects,and using pulse current method,ultra-high frequency method,ultrasonic method,and gas characteristic component detectionmethod to study the variation law of intermittent discharge characteristics of solid insulation defects.The results showthat:the intermittent discharge state of metal fouling defects on the solid insulation surface decreases with the extension of the discharge time,the discharge time interval as a whole shows an increasing trend,and the metal fouling defects on the solid insulation surface in the intermittent discharge state is difficult to develop into a breakdown discharge fault.The overall discharge amount of air gap defects inside solid insulation also shows the law of increasing first and then decreasing,and the discharge amount of air gap defects inside solid insulation stays at a large level for a long time during intermittent discharge,and there is a risk of breakdown,and the discharge will gradually evolve into continuous discharge;ultrasonic method and characteristic component detection method cannot realize the effective perception of intermittent discharge of metal fouling.The 50-period mapping information commonly used in the power field cannot reflect the intermittent discharge variation law of solid insulation,and the 200-period UHF mapping composed of four groups of 50-period UHF mapping data can initially derive the intermittent discharge distribution law of solid insulation defects.The research results of this paper are of great significance to expand the knowledge of intermittent discharge characteristics and the detection of GIS discharge defects in the field.展开更多
方波上升和下降沿处电场快速变化引起的位移电流和空间电磁波对局部放电(partial discharge,PD)的测量造成较大干扰。为此设计并检验了一种基于超高频(super high frequency,SHF,3~30 GHz)信号采集和下混频技术,适用于方波电场下绝缘系...方波上升和下降沿处电场快速变化引起的位移电流和空间电磁波对局部放电(partial discharge,PD)的测量造成较大干扰。为此设计并检验了一种基于超高频(super high frequency,SHF,3~30 GHz)信号采集和下混频技术,适用于方波电场下绝缘系统的PD检测方法。系统性能测试验证了SHF混频法能有效抑制方波电源的干扰,混频信号在降低频率的同时也保留了原SHF信号幅值和相位信息,且系统可检测到视在放电量20 pC左右的PD,灵敏度较好。SHF混频法与脉冲电流法和UHF法的对比实验结果表明,SHF混频法适于检测发生在绝缘强度较高材料中放电速度较快的PD。所设计系统在方波下,对环氧树脂和灌封硅胶两种绝缘封装材料进行了PD对比实验,验证了其实用性。展开更多
基金Project supported by Science and Technology Project of SGCC(Research on Key Technologies for Fault Diagnosis and Early Warning of Intermittent Discharge in UHV GIS:524625200028).
文摘In response to the problem of frequent leakage and false alarm of partial discharge insulation defects in GIS,this paper conducts experimental research on intermittent discharge characteristics of common solid insulation defects in GIS.Using true GIS to build amulti-source testing platform for intermittent discharge of solid insulation defects,and using pulse current method,ultra-high frequency method,ultrasonic method,and gas characteristic component detectionmethod to study the variation law of intermittent discharge characteristics of solid insulation defects.The results showthat:the intermittent discharge state of metal fouling defects on the solid insulation surface decreases with the extension of the discharge time,the discharge time interval as a whole shows an increasing trend,and the metal fouling defects on the solid insulation surface in the intermittent discharge state is difficult to develop into a breakdown discharge fault.The overall discharge amount of air gap defects inside solid insulation also shows the law of increasing first and then decreasing,and the discharge amount of air gap defects inside solid insulation stays at a large level for a long time during intermittent discharge,and there is a risk of breakdown,and the discharge will gradually evolve into continuous discharge;ultrasonic method and characteristic component detection method cannot realize the effective perception of intermittent discharge of metal fouling.The 50-period mapping information commonly used in the power field cannot reflect the intermittent discharge variation law of solid insulation,and the 200-period UHF mapping composed of four groups of 50-period UHF mapping data can initially derive the intermittent discharge distribution law of solid insulation defects.The research results of this paper are of great significance to expand the knowledge of intermittent discharge characteristics and the detection of GIS discharge defects in the field.
