系统单相接地故障对接地变压器负载损耗的影响  

Influence of System Single-phase Grounding Fault on Load Loss of Grounding Transformer

作　　者：陈蕾 咸日常[1] 李飞 谢同平 张冰倩 赵艳雷[1] CHEN Lei;XIAN Richang;LI Fei;XIE Tongping;ZHANG Bingqian;ZHAO Yanlei(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;State Grid Shandong Electric Power Company Zibo Power Supply Company,Zibo 255000,China)

机构地区：[1]山东理工大学电气与电子工程学院,淄博255000 [2]国网山东省电力公司淄博供电公司,淄博255000

出　　处：《高电压技术》2021年第11期3941-3948,共8页High Voltage Engineering

基　　金：国家重点研发计划(2017YFB0902800);国家电网公司科技项目(52094017003D)。

摘　　要：接地变压器作为特种变压器,已在大中型变电站中得到广泛应用,其可靠性直接影响电力系统的安全运行水平。针对接地变压器运行工况复杂、状态检测手段匮乏以及影响其负载损耗变化的因素多等问题,通过推导出不同工况下接地变压器负载损耗的表达式,分析了系统单相接地故障对其负载损耗的影响;在PSCAD软件中建立配电网仿真模型,通过系统单相接地故障时母线电压的仿真波形和故障录波进行对比,验证模型正确性;在此基础上,进一步进行仿真分析,并用实际故障录波验证了仿真结论的可靠性。结果表明:当系统发生单相接地故障时,接地变压器高压绕组有功损耗和负载损耗均剧增,增加值与低压侧负载率呈负相关性,低压绕组有功损耗保持不变;且高压侧有功损耗和负载损耗与系统接地故障点的过渡电阻值呈负相关性,与消弧线圈补偿失谐度呈正相关性,以上结论可为接地变压器运行状态在线检测提供理论参考。As a special transformer,the grounding transformer has been widely used in large-and medium-sized substations,and its reliability directly affects the safe operation level of the power system.In accordance with issues such as the complex operating conditions,lack of state detection means,and many factors of affecting the change of load loss of grounding transformer,an expression of the load loss of the grounding transformer under different working conditions is derived,and the load loss of the system single-phase grounding fault is analyzed.The distribution network simulation model is established in the PSCAD software,and the correctness of the model is verified by comparing the bus voltage simulation waveform and fault recording waveform in case of single-phase grounding fault.On this basis,further simulation analysis is carried out,and the reliability of the simulation conclusion is verified by actual fault recording.The results show that when a single-phase grounding fault occurs in the system,the active power loss and load loss of the high-voltage winding of the grounding transformer increase sharply,the added value has a negative correlation with the low-voltage side load rate,and the active power loss of the low-voltage winding remains unchanged.In addition,the active power loss and load loss on the high-voltage side are negatively correlated with the transition resistance of the grounding fault point of the system,and positively correlated with the detuning degree of the arc suppression coil compensation.The above conclusions can provide a theoretical reference for the online detection of the grounding transformer operation status.

关 键 词：接地故障 接地变压器 负载损耗 过渡电阻 消弧线圈 失谐度 

分 类 号：TM862[电气工程—高电压与绝缘技术] TM41