Design and optimisation of a bidirectional flux modulation machine for AC and DC power supplies

Abstract

This study proposes a novel power supply system that utilises wind power to produce AC and DC power. A special designed generator based on bidirectional flux modulation effect is the key part of the proposed power supply system. The novel power system has a compact structure since the proposed generator has two electric port. There are three essential points that make the proposed system outstanding. One is the contra-rotating rotors, which will cluster wind power even under low wind speed. Second one is the dual armature winding structure, which will provide AC and DC power simultaneously. There are two electric port in the proposed generator. One port can produce AC power to the non-sensitive resistive load. The other can provide AC power with different frequency to the rectifier to obtain DC power. The induced voltage due to flux modulation effect can be used to offer AC power, and the induced voltage due to the outer rotor can be used to offer DC power. The voltage frequency of two sets windings is different. The last one is the air gap flux rotation speed amplification due to flux modulation effect. Time stepping finite element method is used to analyse the dynamic performance of the proposed machine.