Magnetic Field Calculation of the U-Shaped Interior Permanent-Magnet Synchronous Machine Considering the Parallel Magnetization and Bridge Saturation

This work proposes an analytical method for calculating magnetic fields considering the parallel magnetization and magnetic bridge saturation effects. The calculation method can be applied to any irregular regions with high precision and fast calculation speed, enabling accurate magnetic field calculations inside the permanent magnet (PM). First, to address the challenge posed by complex PM shapes in U-shaped interior PM synchronous machine, a novel subdivision equivalence method is conducted. Additionally, using the equivalent PM domain with variable remanence, the saturation effects of the inner magnetic bridge inside the rotor can be calculated. Furthermore, an exact solution for arbitrary partial parallel magnetization in the sector-shaped subdomain and a new method to solve the boundary value problems are introduced. Finally, the calculation results are compared with the finite element method and experiment to verify the effectiveness of this method.