Optimization Design and Research of an Interior Double-Radial Asymmetric Permanent Magnet and Salient-Pole Electromagnetic Hybrid Excitation Generator

Amid the global shift towards sustainable energy, generators are pivotal for efficient and clean energy use. This study introduces an interior double-radial asymmetric permanent magnet (PM) and salient-pole electromagnetic hybrid excitation generator to tackle the challenges of flux adjustment in traditional permanent magnet synchronous generators (PMSGs) and the low power density of electrically excited generators (EEGs). This study theoretically derives equations for the no-load induced electromotive force, voltage adjustment range, and total harmonic distortion (THD) by analyzing generator parameter relationships. Optimization parameters include the offset angles of the double-layer asymmetric PM and the structural parameters of the salient-pole rotor. A multi-objective optimization model is developed with objectives including the no-load induced electromotive force amplitude, voltage adjustment range, and THD. Latin Hypercube Sampling (LHS) is employed to generate samples, followed by sensitivity analysis of optimization parameters. Pareto front analysis and defined parameter matching coefficient are then used to screen the optimization parameters. The optimal magnet pole parameters have been identified. The optimized design results in an 18.7% increase in no-load induced electromotive force amplitude, a 17.6% expansion in voltage adjustment range, and a 38.2% reduction in THD. Finally, a prototype is fabricated and tested. The results confirmed the accuracy of theoretical analysis and the effectiveness of optimization method. The output characteristics of designed generator are significantly improved.