电工实验台热继电器故障频发的研究与分析

Research and Analysis of Frequent Faults of AC Thermal Relay on Electrical Experimental Platform

电工实验室核心过载保护装置热继电器的频繁损坏,严重影响实验的顺利进行。随着电工实验台模块的不断增加,电路结构复杂程度不断上升,实验中频繁使用热继电器会导致其损坏越来越多,进而使实验准备时间成倍增加,极大地影响了学生做实验的积极性。针对以上问题及实验教学的实际需要,采用COMSOL Multiphysics有限元仿真软件,结合Siemens NX软件完成热继电器线圈在持续工作电流及短路电流下,电流、电磁及温度三场的耦合仿真,并通过与实际数据对比分析查找热继电器频繁损坏的根本原因。这为之后的建模仿真打下良好的基础,同时也为实验室继电保护模块的选型提供了依据。

The core overload protection device thermal relay in the electrical engineering laboratory is frequently damaged,which seriously affects the smooth running of experiments.This problem is becoming more and more serious as the number of modules in the lab bench continues to increase and the complexity of the circuit structure continues to rise.Without long-term solution,the relay will only be damaged more and more,the life will be shorter and shorter,the experiment preparation time will increase exponentially,and will affect the students'motivation to do experiments.Based on the above characteristics and practical experimental teaching needs,this paper uses COMSOL Multiphysics finite element simulation software,combined with Siemens NX software to complete the thermal relay coil under continuous operating current and short-circuit current,the thermal relay electromagnetic,current and temperature coupling simulation.Through comparison with actual data and analysis,it has been concluded that the frequent damage of thermal relays is caused by high currents generated by short circuits,which in turn leads to rapid heating of the heating elements.The study lays the foundation for subsequent modeling and simulation,and also provides a theoretical basis for the selection of relay protection modules in the laboratory.