Linear recoil curve demagnetization models for ferrite magnets in rotating machinery

Electrical motors with ferrite Permanent Magnets (PM) are a possible solution when avoiding the usage of rare earth materials in rotating machinery. Irreversible demagnetization of the ferrite PMs is the one of the key challenges that needs to be analyzed in such designs. Nowadays electrical machine design is increasingly relying on Finite Element Analysis (FEA) software that require having accurate and easy-to-implement models for a magnet. Linear Recoil Curve (LRC) models are among the best candidates. This paper studies the LRC models for FEA simulation of ferrite PMs in rotating machinery. Comparison of the model-based results with high accuracy Vibrating Sample Magnetometer (VSM) measured data for a commercially available ferrite magnet grade show that none of the existing temperature dependent LRC models is universal. However, the further development of the studied modelling concept can offer an accurate tool for FEA simulation of ferrite PMs in electrical machines.