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Publications (4)7.15 Total impact

  • Zegang Xu, Shaojun Xie, Peng Mao
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    ABSTRACT: The flux-switching hybrid excitation machine is an interesting brushless machine with magnets and excitation windings in the stator. Due to the unique structure and hybrid excitation, the assignment for electric excitation and permanent magnet excitation becomes a difficult issue. To explore a rapid design method, the nonlinear magnetic circuit analytical model of the element machine has been developed, which introduces the technologies of critical regions subdivision and iterative solutions for magnetic permeability into the magnetic circuit model. Then, the ampere turns of electric excitation, the recommended value of initial magnetic bridge flux density, the influence of stator yoke thickness on magnet dimensions and field regulating coefficient are also included. Finally, the finite element analysis and the experimental results are presented. The proposed method is not only reasonable and effective but also efficient, which provides a reference for the flux-switching hybrid excitation machine (FSHM) design and performance analysis.
    IEEE Transactions on Magnetics 06/2013; 49(6):3002-3008. · 1.42 Impact Factor
  • Zegang Xu, Shaojun Xie, Jiankun Cao
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    ABSTRACT: Flux-switching hybrid excitation machine is an interesting brushless machine with magnets and excitation windings in the stator. In order to provide an analytical technique for the flux-switching hybrid excitation machine (FSHM) design, a nonlinear magnetic circuit method (NMCM) of maximum phase flux-linkage position was proposed. With equivalent magnetic circuit model as original version, NMCM adopts the subdivision technology of magnetic circuit and iterative solutions methods, taking magnetic saturation into account. The ampere-turns of electric excitation, the recommended value of initial magnetic bridge flux density, and the influence of stator yoke thickness on magnet dimensions and field regulating coefficient were also investigated. Finally, the finite element analysis and the experimental results are presented. The proposed method provides reference for the assignment for electric excitation and permanent magnet excitation, and the field regulating coefficient.
    ECCE Asia Downunder (ECCE Asia), 2013 IEEE; 01/2013
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    ABSTRACT: This paper proposes an improved Z-source inverter topology. Compared to the traditional Z-source inverter, it can reduce the Z-source capacitor voltage stress significantly to perform the same voltage boost, and has inherent limitation to inrush current at startup. The control strategy of the proposed Z-source inverter is exactly the same as the traditional one, so all the existing control strategy can be used directly. A soft-start strategy is also proposed to suppress the inrush surge and the resonance of Z-source capacitors and inductors. The operation principle of the proposed topology and comparison with the traditional topology are analyzed in detail. Simulation and experimental results are given to demonstrate the new features of the improved topology.
    IEEE Transactions on Power Electronics 03/2009; · 5.73 Impact Factor
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    ABSTRACT: A new equivalent input circuit of one-cycle-controlled (OCC)PFC converter is built, based on which, the current phase lag issue especially outstanding at low ratio of switching frequency to line frequency is analyzed, and a novel current phase lag compensation scheme by controlling the voltage across the switch is proposed to reduce the phase lag of line current relative to line voltage. Implementation method of the compensation scheme with digital control is introduced, and a design example is given. The stability of the system using the compensation scheme is verified by frequency-domain analysis. The newly built equivalent input circuit can more preciously reflect input characteristics of the OCC PFC converter, and the proposed compensation scheme can reduce the current phase lag, and increase the displacement power factor, which has been verified by experimental results.
    01/2009;