A non uniform air gap hybrid excitation alternator

Many parallel hybrid excitation alternators proposed in the literature have utilized two rotor cores for flux regulation. It increases the size of the alternator. In order to reduce the size of the alternator, an approach for accommodating both excitation windings and permanent magnets in the same rotor core of hybrid excitation alternator is also proposed in the literature. But the output voltage waveform of proposed HEA with one rotor in the literature has higher harmonic content. Hence in order to improve the quality of output voltage waveform, a non uniform air gap hybrid excitation alternator (NUAG-HEA) is proposed in this paper. Detailed simulation results and experimental results are presented in the paper.