Analysis of Self-Excited PM-Assisted Reluctance Generators

Induction machines and reluctance machines have been proposed to the self-excited generating system as isolated power supply in the past few decades. On the other hand, they show either poor voltage regulation or difficulty in excitation. In this paper, the self-excited PM-assisted reluctance (PMAREL) generator is investigated, aiming at overcoming such drawbacks. An analytical model in the dq reference frame is developed to identify the steady-state performance of the self-excited PMAREL generator. Experimental results using a laboratory PMAREL machine are compared to the predicted results. The characteristics of the self-excited PMAREL generator are presented, based on the experimental results. The effects of design parameters (including stator resistances, d-axis inductance, and q-axis inductance) on the generator performance are investigated by using the analytical model. The performance comparisons with a self-excited reluctance generator are also carried out. It is verified that the self-excited PMAREL generator exhibits not only the improvement in terminal voltage, output power, and power factor but also achieves inherently a stable self-excitation process.