Design Optimization of a Homopolar Salient-Pole Brushless DC Machine: Analysis, Simulation, and Experimental Tests

This paper presents the design optimization and experimental tests of a homopolar brushless dc generator. To achieve the required performance within a specified space envelope, the physical dimensions of the proposed configuration were optimized utilizing 3-D finite-element analysis (FEA), subject to maximize the average output power. In this paper, the experimental study and numerical technique as two types of analyses have been utilized to evaluate the proposed machine performance. To validate the correctness of the predicted flux-linkage characteristics, the 3-D FEA method has been utilized as the numerical analysis. In this paper, for improving the flux path in the housing and reduction of the hysteresis and eddy current losses, three axially laminated flux paths are considered which connected two stator sets physically and magnetically. In this paper, regulating the terminal voltage has been investigated by employing the tunable PID controller. Tuning of the PID parameters based on an internal model strategy has been done. Subsequently, flux density in different parts of the prototype machine is measured, and also, a series of experimental tests for no-load and under-load operations at different speeds are carried out to obtain the output characteristics of the machine.