Three-phase flux reversal machine.

摘要

The three phase flux reversal machine (FRM) is a novel electric machine. It has a robust and easy-to-manufacture structure, has a high power density and a wide speed range of operation. Some potential applications of the three phase FRM include aerospace industry, automobiles, industrial drives and servo systems. Basically it is a doubly-salient machine with concentrated windings and PMs on the stator. A comprehensive study of the three phase FRM is presented in this dissertation.;Since the FRM belongs to a new invention, literature on it virtually does not exist. Therefore, some necessary background material is introduced at the beginning of the dissertation, with emphasis on some types of recently proposed doubly-salient permanent magnet machines (DSPMM) and other types of more conventional machines which have close ties with the three phase FRM under study. The operating principle of the FRM is illustrated thereafter. Then, using primarily the classical motor design methodology, a prototype design of the three phase FRM is accomplished successfully. An in-depth study of loss calculation is carried out for the FRM. The prototype machine was built and installed on a test-stand, together with a high speed induction motor which was driven by an inverter. Extensive tests have been performed on the prototype. The equivalent circuit model including core losses is obtained through experiments. Measurements such as power output and back EMF waveform conform to the original design expectation fairly well. Whereas the experimental results validate the prototype design, some problems such as fairly severe flux leakage and cogging torque are also observed. Then, based on the knowledge obtained from experiments and extensive finite element analysis (FEA) calculations, the prototype is greatly optimized, with power density more than doubled and cogging torque drastically reduced.;In order to fully characterize the three phase FRM as a generator (specifically for automobiles), an output controller is built for the FRM to produce a constant voltage output. Both simulation and experimental results demonstrate that the three phase FRM is a viable option for the next generation automotive generators. Finally, motoring operation is studied in some detail at the end of the dissertation. Two control strategies: trapezoidal current control and vector control are presented and encouraging results are achieved. The entire study shows that the three phase FRM is suitable both for generating applications and for industrial drive and servo applications.