Analysis of a Hybrid Excitation Brushless DC Generator With an Integrated Shared-Flux-Path Exciter

A hybrid excitation brushless dc generator (HEBLDCG) system, consisting of a main generator (MG) and an integrated exciter, is proposed and developed in this article. The excitation sources types of the stand-alone generation system and corresponding characteristics of the sources types are summarized. In the target HEBLDCG system, the integrated exciter shares a flux path with the permanent magnet machine part (PMMP), which is a part of the MG, without extracting power from the output terminal or sacrificing the efficiency of the generation system. It is the reactive power in the PMMP that leads to these aforementioned advantages. Also, the basic design flowchart of the exciter is expounded upon, and the values of some parameters are discussed. The designed exciter meets the requirements of the field power of the MG for the whole speed range and under varying load conditions. Based on the well-designed exciter, the electromagnetic performance is analyzed in terms of its open-circuit and load performance. Furthermore, the reason why the output power of the MG is not reduced by the integrated exciter is analyzed. Finally, open-circuit and load experiments for the exciter are conducted, and the proposed excitation method is found appropriate for the HEBLDCG system.