考虑粗糙表面接触的气体绝缘开关设备接头接触电阻数值计算与影响因素分析

Numerical Calculation and Influence Factors Analysis of Gas Insulated Switchgear Connector Contact Resistance Considering Rough Surface Contact

气体绝缘开关设备回路存在大量插接式电气接点,其接触电阻的稳定性直接影响设备的安全稳定运行。基于粗糙表面弹塑性接触理论和有限单元法建立了梅花接头接触电阻数值计算模型。在有限元模型中加入抱紧弹簧与接头材料的弹塑性形变,通过结构场有限元分析获取由抱紧弹簧提供给触点上的接触压力,将计算得到的接触压力作为输入参数带入到基于Bahrami粗糙表面弹塑性机械接触模型中,并计算接头与导体之间的接触电阻。计算结果与110 k V原型气体绝缘母线回路的电阻测试结果基本一致,验证了计算模型的有效性。应用该模型分别分析了导体与接头的对接深度和对接角度对触点接触电阻的影响,计算结果表明:在接头装配公差允许范围内,对接角度变化对接触电阻的影响有限,导体对接深度不足是引起接触电阻异常的主要原因。

Large number of plug-in type connectors existed in the electrical circuit of gas insulated switchgear （GIS）, and the stability of the contact resistance would directly affect the safe and stable operation of equipment. A numerical calculation model for contact resistance of plug-in connector has been developed based on rough surface elasto-plastic contact theory and finite element method （FEM）. The hold spring and the elasto-plastic deformation of joint materials were taken into account in the finite element modeling process, and the contact force provided by hold spring was obtained by structure field finite element analysis. The contact resistance between connector and conductor was calculated by Bahrami＇s rough surface elasto-plastic mechanical contact model with calculated contact force as input parameters. The calculated results are in accordance with the tested loop resistance of 110 kV gas insulated bus bar, which verified the validity of the calculation model. The influences of insert depth and insert angle between connector and conductor on contact resistance were calculated based on the numerical calculation model, the results show that the change of insert angle within connector assembly tolerance has limited influence on the contact resistance, whereas insufficient conductor insert depth is the main cause for abnormal contact resistance.