电磁继电器贮存期接触电阻增长的动力学模型

电磁继电器贮存过程中,触点间的接触电阻超标是主要的失效模式,而触点间的阴离子扩散是导致触点表面绝缘膜增长、接触电阻增加的主要原因。本文分析了纯金属触点表面腐蚀膜的成膜机理,并根据扩散理论给出了接触电阻增长与触点间压力、接触压降以及环境温度的函数关系,建立了常闭触点间单个导电斑点的接触电阻增长动力学模型。该模型与其他学者的实测数据趋势一致,最后通过该模型的计算值与试验结果进行对比,进一步验证了提出的动力学模型的正确性,为进行触点贮存寿命的预测提供了新的思路和参考。

Kinetic Model of Contact Resistance Increment of Electromagnetic Relay in Storage

Electromagnetic relay’s contact resistance overstepped standard is the main failure model in storage.The growth of surface insulating film is influenced by the anion diffusion in contacts.And the growth of surface insulating film is the main reason of contact resistance increment.The ingression mechanism of pure metal contacts surface corrosion film is analyzed.A model,based on diffusion mechanism is derived for contact resistance increasing in a contact material of electromagnetic relays as a function of contact stress,voltage drop across the contacts area and temperature.A kinetic model for evaluating the contact resistance increasing in contact spots of normal close contacts is described.The results show that there is good agreement tendency between the experimental data as reported by different authors in the literature.Finally,the results of calculation and experiment are compared and the validity of the kinetic model presented is verified.And,these studies provide the new ideas and reference for prediction of contacts storage life.