A Non-Linear Permanent Magnet Working Point Migration Model and its Application to Simulation of a Polarized Magnetic System

The paper addresses the issue of the working point migration in non-linear permanent magnets (PM). Starting from the considerations of energy, a novel working-point migration (WPM) model is proposed which can be incorporated into a magnetic equivalent circuit (MEC). The basic theory of working-point migration is discussed which focus on the second quadrant of the magnetic hysteresis loop. The calculation method of the WPM model is proposed based on the relationship between the recoil line model and the affine transformation hysteresis loop. The establishment method for the resultant working point is described by combining the demagnetization curve and the recoil line models in the minor hysteresis loop. The static characteristic of a bistable polarized magnetic system (BPMS), as used in actuators, is calculated using the magnetic circuit method based on the WPM, while a finite element model (FEM) is also derived. The calculation method for the WPM used in MEC is also discussed. The WPM based MEC model yields reasonable results, compared with FEM, of the latching force but with much faster calculation speeds. Furthermore, the working-point state of the PM is clearly illustrated. The test system of the BPMS prototype is established. The test data and WPM model calculation results are compared. It is shown that the WPM model provides accurate prediction of static characteristics of an electromagnetic system.