Research on power density improvement for interior permanent magnet synchronous machine based on permanent magnet minimization

In order to improve the power density of permanent-magnet synchronous machine and reduce cost effective materials, this paper investigated approaches power-density improvement discussed influence flux-weakening level salient ratio parameters on characteristics torque for interior permanent magnet (IPMSM) based (PM) minimisation. Firstly, model PM minimisation can be established principle equal area stator rotor magnetomotive force. According model, a formula is derived calculation structural magnets in IPMSM. Besides, relation among multilayer established. Then, comparing analysing extremum maximum output motor under different parameters, regular IPMSM summarised between parameter internal factor angle. So, it proposed that corresponding angle with respect golden section around −35°. Finally, combined results finite element analytical calculation, 45 kW electric vehicles was manufactured tested no-load, load thermal experiment, respectively. The peak prototype lasted 94 s reached 2.3 times rated torque. Compared conventional used vehicle, increased by more than 0.5 kW/kg which verify correctness theoretical analysis.