Investigating the effect of the mean path length on reluctance actuator output force characterization

Abstract

This paper investigates the effect of the flux's mean path length (MPL) on the reluctance actuator's analytical model. It determines the circumstances where the model neglecting the MPL is valid. The analysis is carried out for both C-Core and E-Core reluctance actuators; the analytical results are calculated by using MATrix LABoratory and then validated against a finite element model simulation by using COMputer SOLution Multiphysics. In addition, the experimental results of the magnetic force of C-Core and E-Core reluctance actuators are presented and compared with the analytical model. The comparison is obtained under different input currents and air gaps for two different ferromagnetic materials. It can be concluded that the analytical model is valid only for air gaps with a relatively high air gap displacement and for small air gaps, considering the MPL is necessary for accurate results. This means that whenever the reluctance actuator is proposed for high-precision motion system applications, it is essential that the analysis takes into account the effect of the MPL.