Design and Dynamic Control of Heteropolar Inductor Machines

  • Jingzhe Wu

Student thesis: Doctoral ThesisPhD


The thesis focuses on a type of electrical machine with a unique structure, namely heteropolar inductor machine. Heteropolar inductor machine is characterised as having both DC field excitation windings and AC armature windings placed on stator side, while maintaining a completely passive rotor. Its robustness offers the machine the potential to serve under extreme conditions, and the thesis discusses the theory, design, control and applications of heteropolar inductor machine. The main achievements are as follows.(1) Space vector method is successfully adopted to construct a dynamic and universal model for heteropolar inductor machine. The strong couplings of air gap permeance variation, armature mmf wave and stator-side field excitation is explained and the machine model is well linked to classical two axis theory of electrical machines with the derivations of important model parameters.(2) The harmonic distortion in heteropolar inductor machine and its influence are addressed and analysed by finite element analysis in the thesis, and potential strategies to overcome the problem are proposed. The machine output voltage waveform and torque ripple are greatly improved by optimisations of winding configuration and rotor shaping.(3) A field oriented control system employing an efficient and effective sensorless control strategy specifically designed for heteropolar inductor machine is proposed. The method takes advantage of the machine’s structural property and estimates the rotor position and speed based on estimation of internal emf. The proposed method is proved to be of much less computational complexity compared with conventional sensorless approaches.(4) A test machine is fabricated together with the implementation of a micro-processor based controller system with sensorless control algorithm embedded. The prototype is tested against the theories developed for both machine modelling and sensorless controller for system verification and validation.(5) A potential application is analysed in the thesis. The overall advantages and disadvantages of heteropolar inductor machine are compared against several candidate machines. A Simulink model is constructed for heteropolar inductor machine based on the developed machine theory, and the performance of a gas turbine starter generator integrator with a heteropolar inductor machine is evaluated via simulation.
Date of Award4 Nov 2015
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorMartin Balchin (Supervisor) & Francis Robinson (Supervisor)

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