Finite Element Analysis of Flux-Switching PM Machine Considering Oversaturation and Irreversible Demagnetization

A typical 12/10 flux-switching permanent magnet (PM) machine is analyzed using finite-element (FE) method with special considerations of the silicon steel oversaturation, PM irreversible demagnetization, and the dc-biased magnetic induction on the hysteresis loss. The high flux density range of B-H curve which is difficult to measure is deduced with the combination of polynomial extrapolation and silicon steel saturation magnetization. A temperature-dependent sloped linear PM demagnetization model is incorporated into the FE model to analyze PM irreversible demagnetization and estimate the maximum allowable working temperature for PM. The influence of dc-biased magnetic induction on hysteresis loss is taken into account in core loss calculation. The FE analysis package is developed with the help of FE program generator.