220 kV电缆中间接头操作过电压及抑制措施研究

Analysis on Switching Overvoltage and Suppression Method of Cable Joint in 220 kV Cable Line

电缆线路合闸时发生的电缆接头击穿事故时有发生,而此前电缆系统过电压仿真中均将电缆接头忽视。为此针对某220 kV电缆线路的中间接头结构,建立接头等效阻抗模型,并在暂态仿真软件ATP-EMTP中搭建考虑电缆中间接头的220 kV高压电缆系统仿真模型,仿真计算电缆中间接头的线芯与金属护层上承受的操作过电压,并研究母线不同出线数以及电缆线芯残余电荷等影响因素对电缆接头操作过电压的影响。此外还分析了电缆接头操作过电压的抑制措施。研究结果对电缆接头的故障分析、电缆绝缘配合的参数设计提供参考。

Disastrous breakdown accidents of cable joints happen frequently,when the closing operation of the switches is taken.However,the cable joints are often ignored in the simulation of overvoltage of cable system.In this case,based on the structure ofthe 220 kV cable joint,the equivalent impedance model is established in the paper.Impedance parameters of the cable joint are obtained by the way of measurement,and the simulation model of the 220 kV high voltage cable system considering the cable joint is built in the transient simulation softwareATP-EMTP.The simulation of switching overvoltage on the cable core and metal sheath of cable joint is conducted,and impacts on switching overvoltage of cable joints by influence factors including different number of outlets from buses and residual charges of cable core are analyzed.In addition,the analysis on suppression method of switching overvoltage of cable joint is made.Results give a reference to breakdown analysis of cable joints and parameter design of cable insulation co-ordination.