Analysis And Optimisation Of Contact Bounce Characteristics Of AC Contactors

The AC contactor is a widely used low voltage electrical switch.When the contactor is energised,the collision and bouncing phenomenon caused by arc ablation will shorten the electrical life of the contactor.To address the vibration bouncing problem caused by the collision contact of dynamic and static contacts during the closing process of AC contactors,the vibration equation of the contactor contact system is established based on a comprehensive consideration of non-linear electromagnetic forces and collision contact forces.Using the ADAMS/View AC contactor prototype model,the corresponding mechanical parameters are selected as design variables to optimize the design of the contactor contact system by an improved genetic algorithm.The innovative results obtained were verified by comparing experimental and theoretical results as follows.(1)From the perspective of mechanical vibration,an AC contactor vibration model is established,and the contactor system bouncing law is revealed by solving the vibration equation;at the same time,a vibration model with the addition of a vibration absorber is established,and the mechanism of the suppression effect of the vibration absorber on the contactor is obtained.(2)Through the improvement of the genetic algorithm,the optimal parameter scheme of the AC contactor is obtained under the satisfaction of various constraints;the population generation mechanism and elite maintenance strategy adopted achieve the dynamic adaptive adjustment of the crossover probability and variation probability with the similarity of population individuals,and the correctness of the improved genetic algorithm is verified using specific arithmetic examples.(3)The improved genetic algorithm program was called through the ADAMS/View user-defined interface to realise the simulation of the whole process of dynamic contact and dynamic core bouncing with mechanical parameters as design variables,verifying the accuracy of the theoretical calculation;meanwhile the dynamic characteristics of the contactor prototype were improved and the overall performance was significantly improved.(4)For the first time,the dynamic process of contact bouncing was visualised through high-speed photography,revealing the contact bouncing deflection pattern;the action mechanism of rebound friction after collision was analysed using a picture processing program,providing a new method for further comprehensive optimisation of the contactor prototype.