The efficiency estimation of 15–10 double salient-pole Homopolar Brushless dc Generator

This paper presents the efficiency estimation of a double salient-pole Homopolar Brushless dc Generator in order to determine the optimum operation. For the under consideration generator an assistant dc field is replaced with permanent magnet in the rotor. Varying the amplitude and direction of the current in the field coil can control the generated output voltage to a level between zero volts and the maximum voltage. In this analysis, evaluation of the core iron losses resulting from eddy current and hysteresis, and also copper losses for both phases coil and field coil are investigated. The iron losses are then derived and evaluated for no-load. To evaluate the accuracy of the calculated parameters, the numerical technique has been utilized. In the numerical analysis, for a three-phase 15/10 Double Salient-Pole Homopolar Brushless dc Generator as a design example, 3-D Finite Element (FE) analysis has been carried out using a MagNet CAD package (Infolytica Corporation Ltd.).