Simulation of AC Contactors Fed by a Distorted Source Using the Coupled Finite Element Method, Circuit and Mechanical Equations

This paper deals with the simulation and analysis of dynamic behaviour of electromagnetic AC contactors, when is fed by a voltage distorted source. The behavior under these conditions could compromise the operations in industrial plants, electric machines, etc. The contactor is modeled by 2D finite elements method (FEM), coupling with its mechanical and electrical equations. Analysis of results is based on the magnetic force which denotes the performance in opening and closing behavior of the device

I. Introduction

Contactors are electromechanical devices composed by a set of springs and a magnetic circuit. They act as switches in a variety of power and control systems. When a voltage is applied to the coil, electromagnetic forces attracts mobile part toward the fixed part in order to close the external contacts of the device. Problems may occurr when the mobile part is disconnected from the fixed part due to a power disturbance.