Dynamic Analysis And Design Of Disc Brushless Doubly-fed Machine

A new type of AC motor-Brushless Doubly-fed Machine (DBDFM) is proposed in the research, which is cascaded by two sets of relatively independent disc motor unit. The motor is provided with advantages of winding asynchronous motors and electrically excited synchronous motor. To use disc structure has the advantage of high coupling capability, high power density and high material utilization. The motor can operate in asynchronous, synchronous and doubly-fed, and so on mode, and can be used in VSVF wind power system and fan pump class load VVVF system, it will reduce system costs significantly, improve system reliability, and develop broadly.Firstly, working theory of DBDFM and realization method of various operating states are analyzed, DBDFM equivalent circuit is derived through the establishment of the voltage equation, and then the power processes of the motor and power balance relations in variety of operating conditions are analyzed.Secondly, a variety of operation modes of DBDFM are researched. General mathematical model of DBDFM in ABC stationary frame is derived, terminal voltage constraints are given in various operating modes, and the simulation program preparation of the prototype in a variety of operating modes are written. Steady-state operating characteristics, starting characteristics, pull-in characteristics and the dynamic operating characteristics in a variety of operating modes of DBDFM are studied. Simulation results show that prototype design is reasonable and theoretical analysis is correct.And then, structural characteristics of DBDFM are introduced. On the basis of analysis of the motor's magnetic circuit characteristics, using MATLAB software write the electromagnetic design program of DBDFM, DBDFM with (4+2) pole is designed.Finally, the experimental platform is built to have an experiment of the prototype. Electrical experiments verify theoretical analysis is correct, and realize variable frequency speed in double-fed running state; during the power generation experiment process, when the rotational speed fluctuate, frequency of the preserve power unit is unchanged by changing the control winding's frequency, it can realize VSVF power generation.