Equivalent Magnetic Network Model of Electrical Machine Based on Three Elements: Magnetic Flux Source, Reluctance, and Magductance

In order to solve the problems of mesh node dynamic connection between the stator and rotor and the inability of single reluctance element to characterize the eddy current and hysteresis effects of ferromagnetic materials in the conventional equivalent magnetic network (EMN) model, this article proposes an EMN model with three elements: magnetic flux source, reluctance, and magductance (TEEMN). The “magnetic flux source” is arranged in the air-gap mesh, whose magnitudes can be quickly determined by the analytical method. Changing the magnitudes of the magnetic flux source to imitate “virtual rotation” of the rotor solves the problem of mesh dynamic connection of the EMN model. At the same time, the “magductance L” element is introduced to characterize the influence of eddy current and hysteresis effects on the magnetic flux density. Further, considering the saturation effect of the magnetic circuit, a calculation method of the saturation factor of “effective magnetic impedance” is proposed to further improve the calculation accuracy of the TEEMN model. Taking a dual three-phase vernier permanent magnet (PM) machine as an example, the modeling process and analysis method of the TEEMN model is presented in detail and verified by the finite element analysis results and experimental results.