110 kV电缆中间接头的合闸过电压仿真研究  

Study on Closing Overvoltage Simulation of 110 kV Cable Intermediate Joint

作　　者：王华楠 王霞[1] 余栋 舒子航 崔江静 仇炜 WANG Huanan;WANG Xia;YU Dong;SHU Zihang;CUI Jiangjing;QIU Wei(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China;Zhuhai Power Supply Bureau,Guangdong Power Grid Limited Liability Corporation,Guangdong Zhuhai 519000,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [2]广东电网有限责任公司珠海供电局,广东珠海519000

出　　处：《高压电器》2021年第7期127-134,共8页High Voltage Apparatus

基　　金：广东电网有限责任公司珠海供电局科技项目(GDKJXM20161743)。

摘　　要：近年来发生多起110 kV电缆中间接头在断路器合闸时爆炸的事故。为研究110 kV电缆接头在断路器合闸送电时的过电压特性,首先建立了电缆中间接头的RLC等效模型;然后在PSCAD软件中搭建含有中间接头的电缆线路模型,分析合闸相角、电缆长度、接头数量对接头过电压的影响,找出过电压最严重的接头;再利用Ansys软件仿真过电压情况最严重的接头内部电场分布。结果表明:B相线路60%~90%处的接头过电压最严重;合闸过程中接头屏蔽层的电压含有超过40 kHz的高频分量;过电压最严重的接头内部硅橡胶与交联聚乙烯界面场强最大值和高压屏蔽管端部场强最大值均比没有过电压时增加1倍,界面场强最大值超过了安全阈值;且断路器的不同期合闸使得接头承受多次过电压造成的复合界面和高压屏蔽管端部场强的突增以及屏蔽层的高频振荡,容易引发接头故障。In recent years,the explosion of 110 kV cable intermediate joint has happened for many times during the closing operation of circuit breaker.For studying the over voltage characteristic of 110 kV cable joint at closing operation of the circuit breaker for power transmission,the RLC equivalent model of cable intermediate joint is set up firstly,then,the cable line model containing the intermediate joint is set up in PSCAD software,the influence of closing angle,the length of cable and the number of joints on over-voltage of the joint is analyzed and the joint with the most serious overvoltage is found.Additionally,the internal electric field distribution of joint with the most serious overvoltage is simulated by Ansys software.The results show that the overvoltage of the joint at 60%~90%of cable in phase B is the most serious.During the closing period,the voltage in the joint shielding layer contains high frequency component over 40 kHz.Moreover,the maximum electric field strength on the interface between silicone rubber and cross-linked polyethylene and the maximum field strength at the end of the high voltage shielding tube are doubled than when there is no overvoltage and the maximum value of the interface field strength exceeds the security threshold.The sudden increase of field strength on the composite interface and at the end of high voltage shielding tube and the high frequency oscillation in the shielding layer due to the joint withstanding multiple times of the over voltage,which is caused by asynchronous closing of circuit breaker,is likely to cause fault of the joint.

关 键 词：电缆中间接头 过电压 合闸相角 界面 电场分布 

分 类 号：TM75[电气工程—电力系统及自动化]