Homopolar Generators: an Overview

Homopolar generators are a particular class of electrical machines capable of generating DC current without the use of mechanical commutators or electronic rectifiers. This paper presents an overview of the typical configurations of homopolar DC machines. The paper focuses on generating operation, trying to assess the optimal configuration for a high efficiency generator. Among the possible solutions, a specific configuration which uses permanent magnets for the excitation field was chosen and built to perform a set of experiments.