A Distributed Time-Modulated MMF and Dynamic Permeance Applied for Magnetic Equivalent Circuit Model of A Compressor PMSM

This article establishes a magnetic equivalent circuit model for a compressor permanent magnet synchronous motor (PMSM) based on a distributed time-modulated magnetomotive force (MMF) represented by equivalent excitations on fixed air-gap branches and dynamic permeance. The distributed time-varying equivalent excitations can represent the MMF distribution induced by the permanent magnet (PM) across the air gap, solving the dynamic connection problem of the traditional magnetic equivalent circuit (MEC) model. An adjustment matrix is introduced to dynamically update the rotor permeance matrix through weighted compensation. This approach effectively addresses the mismatch between the distributed time-varying equivalent excitations and the rotor permeance branches, which typically arises from the dynamic variations of the excitations. In addition, a relative permeance function is employed to dynamically adjust the air-gap permeance, explicitly accounting for the influence of stator slotting on the magnetic field distribution. The accuracy of the proposed modeling approach is rigorously validated by comparing its results with both finite element analysis (FEA) simulations and experimental measurements.