Design Consideration of Eddy-Current Loss for Rotor of HIA With Rectifier and Capacitive Loads

Homopolar inductor alternator (HIA) with rectifier and capacitive loads is a promising choice for pulsed power supply. The solid-iron rotor of HIA can rotate at a very high speed, but this causes serious eddy-current loss in the rotor and results in local overheating on rotor face. In this paper, the analytical method was used to calculate the rotor eddy-current loss for HIA with rectifier and capacitive loads, and the effect of eddy-current shielding on the rotor eddy-current loss was also discussed. The analytical results are coincided with the results simulated by a simplified 2-D field-circuit coupled simulation. This paper shows that in order to reduce the rotor eddy-current loss, the air-gap length and the pole number should be as large as possible and the windings should be distributed and short-pitch. Meanwhile, an important conclusion is that the eddy-current shielding cannot decrease the eddy-current loss for HIA with rectifier and capacitive loads; on the contrary, it increases the eddy-current loss, compared to the case with the rectifier and resistive load.