Electromagnetic Design And Running Performance Of Brushless Of Wound-Rotor Doubly-fed Machine

Brushless doubly-fed machine(BDFM)is a new type of AC motor,in the variable speed drive and Variable-Speed Constant-Frequency have shown a good application prospects.The stator of the brush doubly-fed machine consists of two sets of windings of two different poles.The rotor consists of a set of rotor windings.The design method of the wound rotor is flexible and reasonable,which can effectively reduce the unwanted harmonics in the rotor and lay the foundation for the practical application of the large-capacity brushless doubly-fed machine.Firstly,this paper analyzes the basic principle and operation modes of the brushless doubly-fed machine,deduces the formula of winding brushless doubly-fed motor,and establishes the mathematical model of motor.In this paper,the steady-state equivalent circuit of the wound rotor brushless doubly-fed machine and its equivalent circuit in the stand-alone power generation operation are discussed in detail.Secondly,about the electromagnetic design this paper gives the basis of brushless doubly-fed machine fixed rotor slot,the choice of the number of poles,and the influence of the number of poles on the motor performance.The wound rotor windings based on the "pole change method" and "tooth harmonic method" be analyzed.Based on the "tooth harmonic method",a concentric rotor structure brushless doubly-fed machine was designed by using the sinusoidal winding theory.This paper systematically studies the control strategy of the operation of the brushless doubly-fed machine: the scalar control strategy,the vector decoupling control strategy and the closed-loop control strategy based on the experimental data.Finally,based on Y315,a prototype of 64 kW marine brushless doubly fed power generation system was designed,the finite element analysis method was used to analyze the prototype.Based on the prototype,a brushless doubly-fed generation control system for marine shaft be established.Simulation and prototype experiments showed that the prototype has good no-load and load-carrying characteristics.