Research On Dynamic Characteristics And Failure Mechanism Analysis Of The AC Contactors Under The Vibration Condition

The AC contactor is a kind of controllable switching appliance used to frequently switch on and off the AC main circuit and the medium or large capacity electric equipment.With the input of new power equipment,the working environment of many electrical products including contactors is harsh.Among them,the vibration is a relatively common objective factor.Whether a contactor can operate stably and reliably in a vibration environment is directly related to the safety of power equipment.The dynamic response characteristics during the closing process are important performance indicators reflecting the reliability of the AC contactor.It is of great significance to deeply study the impact of vibration on the dynamic characteristics of the AC contactor and analyze its failure mechanism.This paper analyzes the impact of vibration stress on the performance degradation of the contactor electromagnetic mechanism,and aims to study the failure mechanism of the AC contactor under vibration conditions.Firstly,a 3D finite element model of the electromagnetic mechanism is established using Ansys Maxwell software,and a hybrid AC contactor dynamic simulation model is designed based on this.Based on the finite element simulation of the transient magnetic field,the end stage of the closing process is solved twice by the mechanical dynamic equation of motion.This not only improves the calculation efficiency of the transient magnetic field simulation model,but also enables more accurate solution and analysis of key dynamic characteristics.Secondly,based on the hybrid simulation model,the dynamic characteristics of the AC contactor electromagnetic mechanism during the suction process are studied,and the energy distribution model is established based on the working parameters of the simulation calculation.The impact energy of the dynamic and static iron cores will have a certain effect on the contact characteristics,and then affect the electrical durability and overall performance of the AC contactor.From the perspective of energy conversion research,the closing process of the electromagnetic mechanism is analyzed.Through the calculation and analysis of the energy distribution during the closing process at different closing phase angles,the different dynamic characteristics of the contactor electromagnetic mechanism are studied.Subsequently,a comparative test of the dynamic characteristics of the contactor under normal and vibration environments is performed.In order to verify the correctness of the simulation model calculation and to further analyze the impact of vibration stress on the dynamic characteristics of AC contactors,a test platform for dynamic characteristics of AC contactors is designed and built.Using this test system to conduct dynamic test of AC contactor under normal and vibration environment respectively,real-time measurement of the characteristic parameter signal of the AC contactor during the closing process is realized,as well as the extraction of multiple dynamic parameters and online calculation.It also provides data support for subsequent research on failure mechanism analysis of AC contactors under vibration stress.Finally,the effect of vibration stress on the dynamic performance of AC contactors is studied from the perspective of mechanism analysis.The vibration is added as an additional input energy to the energy distribution model of the contactor electromagnetic mechanism during the closing process,and the steady state response of the AC contactor electromagnetic mechanism under different forms of vibration is calculated and analyzed.By studying the impact of vibration stress on the collision energy of the iron core,and then analyzing the changes of the dynamic response parameters of the AC contactor in a vibrating environment,it is possible to effectively reflect and explain the uncertain impact of the vibration stress on the dynamic performance parameters of the AC contactor from a mechanism perspective.