A novel variable flux reluctance generator for vehicles

The general vehicle generators are claw-pole synchronous generators, which have the problems such as complicated processing technology of claw poles, low reliability of brushes and low operating efficiency. In this paper, a novel variable flux reluctance generator (VFRG) for vehicles is introduced and it is different from common reluctance machines. It has field coils on each stator pole and forms sinusoidal flux-linkage at each phase's winding. Compared with general vehicle generators, it has the advantages of simple structure, strong robustness and high efficiency. The structure and operating principle are illustrated at first. Then a VFRG vehicle generator of 28V output voltage for 24V power systems is designed and optimized, which has low cogging torque as well as sinusoidal back-EMF waveforms. In addition, the characteristics and voltage ripple are obtained by simulation. And the technical specifications meet the requirements for a vehicle generator to work in a wide speed range. The results validate the applicability and superiority of VFRG to be a novel generator for vehicles.