Flux Saturation Model of Interior Permanent Magnet Synchronous Motor Considering Magnetic Flux Saturation Phenomenon near Bridges and Ribs

This study proposes a flux saturation model for interior permanent magnet synchronous motors (IPMSMs). This model considers the saturation phenomenon near bridges and ribs. In IPMSMs, bridges and ribs are physical structures necessary to place permanent magnets inside the rotor and to create saliency. However, due to this physical structure, magnetic flux is formed near the bridges and ribs in IPMSMs. In an ideal scenario, the stator encounters minimal leakage flux. The stator flux closely resembles the linkage flux and is used for motor control. However, FEA confirmed that the amplitude of the magnetic flux near the bridges and ribs was sufficiently large to affect the stator flux. Magnetic equivalent circuit was utilized to analyze the effect of bridge and rib saturation on the d-q axis stator. The validity of the analysis was verified using FEA data. Based on the analysis, the effect of magnetic flux saturation near the bridges and ribs on the stator magnetic flux was modeled using a formula. The proposed flux saturation model was confirmed using FEA data from a 150 kW IPMSM for electric vehicles and experimental data from an 11 kW general-purpose IPMSM.