| As a solution to the magnetic field regulation problem in traditional flux-switching permanentmagnet machines, this paper presented a novel parallel hybrid excited flux-switching machine.Composed of an electrical part and a PM part, this machine has almost all the advantages of aflux-switching permanent magnet machine, such as high power density, high torque density, simplerotor structure, intrinsic sinusoidal back EMF and so on. Due to the independency between theelectrical part and the PM part, it’s flexible in machine design.Based on FEA, this paper made comparisons upon structures and electromagnetic characteristicsamong different topologies of electrical exciting flux switching machines, and then focused on aparallel hybrid excited flux-switching machine, analyzed its detailed inductance characteristics andthe field-weakening performance, and above all, established the mathematical model. The researchshowed that due to the existence of electrical part, a parallel hybrid excited flux-switching machinehas larger inductance, so that it takes on good capability of symmetrical magnetic field regulation andextended flux weakening range. By means of regulating armature current and field currentsimultaneously, the flux linkage can be counteracted easily when failure occurs.Additionally, in order to increase the system efficiency, this paper presented a new control strategyby making the best use of the field current to achieve maximum torque/copper. For a givenelectromagnetic torque, a fitting equation between field current and electromagnetic torque can beestablished and then q axis current can be calculated. In this paper, the presented method was appliedboth below and above base speed, further more, the applicable range of id=0-maximum torque/coppercontrol strategy is extended. The simulation study and experiment results showed that he presentedstrategy can achieve almost maximum Te/Pcuand minimum copper loss so that the efficiency ofPHEFS machine is increased effectively. |
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