A Type of Attractive Force Calculation Model of Polarized Relay Based on Nonlinear Permanent Magnet Bar Subsection Model

In polarized relay, the armatures are sometimes made of permanent magnet (PM). The attractive force calculation is very important in the design and analysis of polarized relays. For some polarized relays which use less expensive permanent magnet bars that have nonlinear magnetic properties, the modeling of such nonlinear permanent magnet (NPM) bars is particularly important to the design of relay contact force, operation speeds and subsequent effects on switching performances. In this paper, an Equivalent Magnetic Calculation model of a NPM polarized relay is built based on a subsection model. The subsection interfaces of NPM are analyzed and the leakage permeance between the armature and yoke is calculated. Then the electromagnetic force is calculated on various rotation positions. This is compared with a finite element method (FEM) and the accuracy of the subsection calculation model is verified.