Abstract：Building the accurate equivalent circuit model of the brushless doubly-fed machine (BDFM) and analyzing the harmonic effect on the performance of the machine is the purpose of this paper. Based on the basic electromagnetic relation and the fundamental equivalent circuit for BDFM, the harmonic equivalent circuit is presented and the chain equivalent circuit model of BDFM considering the effect of the harmonic content is built in this paper. The calculating formulas of the parameters and the state equation in the chain equivalent circuit model are given. As an example, the mechanical characteristic of a practical wound-rotor BDFM is calculated by the chain equivalent circuit model and compared with the calculated results of the fundamental equivalent circuit model and the measured results. The proposed equivalent circuit model and the calculation methods are valid by the comparison of the measured and calculated results of the prototype machine.
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2010, Vol. 25 
