基于冲击理论的接触器触头弹跳建模及分析

Modeling and Analysis of Contactor Contact BounceBased on Impact Theory

立足于某电站35 kV电网母线设备柜PT烧毁,进行电力网络中接触器弹跳研究。基于多刚体碰撞接触冲击理论模型,进行通用接触器开关特性及弹跳模拟研究,旨在辅助电力网络从算法角度实现接触器闭合行为的建模,并能够模拟接触器切换负载时的动力学特性。给出了接触器的动触头运动轨迹的碰撞弹跳方程,并通过模型研究了弹跳发生的物理机理。实验结果表明,开发的弹跳计算程序可有效评估接触器动态特性。最后,结合电力网络中常见的典型控制电路,利用开发的弹跳计算程序分析了容性负载条件下接触器的触头开距、负载电压及接触电阻对触头闭合弹跳特性的影响,从而为后续电力网络中同类开关电器弹跳抑制研究提供参考。

In view of the background of a 35 kV power grid cabinet in a power station,the contact bounce in a power network is studied.Firstly,based on the collision contact impact theoretical model of multi-rigid system,the switch characteristics and bounce simulation of the universal contactor were studied.The purpose of this paper is to assist the power network in modeling and analyzing the contactor closing behavior from an algorithmic perspective.Besides,the model can simulate the dynamic characteristics of contacts under loads condition.After that,the motion orbits dynamic equations of the moving contact for contactor are given,and the physical mechanism of the bounce occurrence is studied through the model.The experimental results show that the developed bounce calculation program can effectively evaluate the dynamic characteristics of the contactor.Finally,combining the typical control circuits of power systems commonly used in power networks,the developed bounce calculation program is used to analyze the influence of contact gaps,load voltages,and contact resistances on their bounce characteristics under capacitive loads.It can provide a reference for bounce suppression study for similar switching appliances in subsequent power networks.