直流继电器电寿命试验中复合触头的温度场和热应力仿真研究

Simulation and Analysis of Temperature Field and Thermal Stress of Composite Contacts in Electrical Life Test of DC Relay

在较大负载等级下,复合触头的结合强度会由于温度和热应力的影响发生变化,甚至导致氧化物层脱落而失效。以典型的AgSnO2In2O3/Cu复合触头为研究对象,基于有限元思想提出一种电器多个动作周期后的温度、热应力仿真计算方法,从而得到复合触头在电寿命试验中的温度场、热应力分布的变化规律,又进一步研究了大负载情况下,复合触头的结合强度、银氧化层厚度等因素对其寿命的影响规律,并通过与试验结果对比验证了仿真模型的正确性。

At the heavy load level,the bonding strength of the composite contact will change due to the influence of the uneven temperature and stress distribution,which may even cause the failure in the form of oxide layer peeling. Regarding the typical AgSnO2In2O3/Cu composite contacts as the research object,a simulation model and numerical calculation method were proposed to calculate the contact temperature and thermal stress after any operation cycle. Based on the method,it is figured out the distribution of the contact temperature and thermal stress changing with the electric life test. The influence of the oxide layer’s thickness on the distribution of contact temperature and thermal stress was investigated. The research in the paper is a good trial to analyze the composite contact’s properties by numerical calculation method and provides a reference good for selection of the composite contact material and optimization design of the electrical apparatus.