The doubly salient permanent magnet (DSPM) machines are very attractive for low-speed power generation. In this work, we propose a design technique to improve the output power of the DSPM generator by an adjustment of pole configuration. The number of stator and rotor poles, split ratio, as well as the stator pole arc of the generator, were proposedly adjusted and optimized. The output characteristics of the generator including the magnetic flux linkage, electromotive force, harmonic, cogging torque, electromagnetic torque, output voltage and output power were analyzed through finite element analysis. The symmetrical magnetic field distribution of all generators was firstly verified. Then, the results indicated that this particular generator was optimized at 18 stator poles and 12 rotor poles, while the split ratio and the stator pole arc should be set as 0.78 and 6.15 degrees, respectively. The proposed optimal generator could provide a significant improvement in the output voltage and the output power compared to the conventional structure. The output power of 1.28 kW can be reached by the optimal structure, which was two times higher than that of the conventional structure. The physical explanation regarding to the structural modification was also given. The proposed design technique can be applied for improving the output power of the DSPM machines.
Design of a three-phase multistage axial flux permanent magnet generator for wind turbine applications
