Finite element analysis of electromagnetic relay under the impact of disturbing magnetic field

Abstract

Electromagnetic (EM) relay is a commonly used electronic control component, which is extremely sensitive to magnetic field. With the increasing magnetic field around tokamak devices, the reliable operation of EM relay is greatly threatened. Therefore, it is necessary to study the failure mechanism of EM relay under disturbing magnetic field. In this paper, a fully coupled analysis model of EM relay, including electric circuit, magnetic field and mechanical motion, is established. Taking plunger-type DC EM relay as an example, the influence of disturbing magnetic field of EM relay is studied. The relationship between the disturbing magnetic field and the action time, holding force, and some other parameters of the relay is given. Moreover, the failure magnetic field threshold is obtained. An efficient method to suppress the impact of disturbing magnetic field on the relay is proposed. The work presented in this paper has a great significance to improve the reliability of EM relay in the disturbing magnetic field and ensure the stability of tokamak devices.