Magnetic field analysis and performance optimization of hybrid excitation generators for vehicles

Due to the increase of magnetic potential sources and complex magnetic circuit, the hybrid excitation generator (HEG) used in the energy conversion system of the vehicle has the problems of various structure parameters, complicated magnetic field analysis, and complex performance optimization, which can lead to the heavy workload and low accuracy of the traditional analysis method. For these problems, the paper proposes an analytical method of the HEG main magnetic field. The method considers the stator slotting and rotor magnetic circuit distribution and takes Carter coefficient and rotor magnetomotive force as the main calculation parameters. Compared with traditional methods, this method can analyze the various topology of HEG in detail and improve the accuracy of magnetic field analysis. Using this method, the main magnetic field of a new parallel HEG with a combined-pole permanent magnet (PM) rotor and salient-pole electric excitation rotor (EER) is analyzed, the main influencing parameters are determined, and the electromagnetic characteristics of HEG are analyzed to complete the performance optimization. The prototype is trial manufactured and tested. The results show that the optimized HEG can significantly improve the sinusoidal waveform of induced electromotive force (IEMF) and optimize the overall electromagnetic performance.