Simultaneous PM Temperature and Magnetization State Estimation in Variable Flux PMSMs Based on the PM Flux Linkage

In VF-PMSMs, PM temperature increase leads to a reduction on torque production capability and to a variation on coercive force in PMs, therefore affecting the magnetization state (MS) control. Due to this, PM temperature monitoring in VF-PMSMs is of upmost importance. However, available estimation methods cannot be extended to VF-PMSMs since they assume constant MS. This paper proposes a method for simultaneous MS and PM temperature estimation in VF-PMSMs.