Investigation of Output Power and Efficiency of Wound-Rotor Brushless Doubly-Fed Machine

Abstract

Brushless Doubly-fed Machine (BDFM) is a new type of the induction machine, which has wide application in the fields of variable-speed generator and drive systems. The key factor affecting its performance is the rotor structure. In this paper, taking wound-rotor BDFM for instance, firstly, according to the relationship between the equivalent circuit parameters of the BDFM, the core equivalent circuit model of the BDFM has been derived. Secondly, based on the core equivalent circuit model and the constraints of electromagnetic load, the power distribution between the power and control windings and the constraint condition of maximum output of active power has been obtained. Thirdly, according to the simplified model of the equivalent circuit, the copper loss and the relationship between the output power and efficiency of the machine have been investigated. Finally, the anlysis results are verified by the experimental data.