光伏并网电站监测技术及绝缘故障分析  

MONITORING TECHNOLOGY AND FAULT ANALYSIS OF PHOTOVOLTAIC GRID-CONNECTED POWER STATION

作　　者：金立军[1] 潘岩 黄佳其 Jin Lijun;Pan Yan;Huang Jiaqi(College of Electronic and Information Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学电子与信息工程学院,上海201804

出　　处：《太阳能学报》2025年第3期365-372,共8页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(52277157)。

摘　　要：在分析并网点电压畸变的各种影响因素基础上,建立T型并网线路简化阻抗模型,通过仿真分析探寻光伏并网电站电压互感器绝缘损坏的机理。采用暂态对地电压(TEV)法测量开关柜局部放电、超声波法判断放电点位置,结合电能质量在线监测装置判断出现局部放电的原因。实验数据表明:该电压互感器长期承受5次谐波越限,绝缘逐步损坏,出现气隙放电,最终导致炸裂。现场对静止无功发生器(SVG)和电压互感器二次回路消缺后,运行恢复稳定,验证了实验分析的准确性。A simplified impedance model of T-type grid-connected line is developed based on analyzing of various factors influencing voltage distortion at the grid connection point.Furthermore,the cause of voltage transformer insulation damage in PV grid-connected power stations is explored through simulation analysis.The TEV method is used to measure the partial discharge of switchgear,the ultrasonic method is used to determine the location of the discharge point.when combined with a power quality online monitoring device,it enables accurate identification of the underlying causes behind such partial discharges.The experimental data demonstrate that the voltage transformer has been exposed to five harmonics exceeding the limit for an extended period,resulting in insulation degradation and air gap discharge,ultimately leading to explosion.After rectifying the defects in SVG and addressing the issues with the secondary circuit of the voltage transformer,system operation restored to stability,which verifies the accuracy of the experimental analysis。

关 键 词：光伏电力系统 局部放电 故障分析 状态检测 电路谐振 谐波 

分 类 号：TM615[电气工程—电力系统及自动化] TM855