Field-Circuit Coupled Finite Element Simulation Of Doubly-Fed Brushless Motor Control System With SVPWM

The doubly-Fed brushless machine (DFBM) has a series of merits, such as robust structure, adjustable power factor, small inverter capacity, high reliability, low manufacturing cost, etc. It is attractive for high power and high voltage variable-speed driving system and variable-speed constant-frequency generating system applications.As an academic focus, DFBM adjustable speed system is currently at the stage of simulation and trial production. Though there are many studies about the DFBM and the control system respectively, the research about the whole adjustable speed system is almost blank. Most studies are about DFBM and the control system separately rather than consider them as a system. Besides, structural optimization and parameter testing of the prototype also need the support of high performance simulation method. Hence, a high performance simulation method should be worked out for technical support.Owing to the novel structure of stator and rotor and their complicated electromagnetic relationship, the traditional AC machine design and analysis method is not suitable for the DFBM adjustable speed system. Also, complex circuit, such as SVPMW and vector control system, can’t be simulated by electromagnetic analysis software directly, which leads to the failure of model construction. In this paper, the method of co-simulation is adopted, which make two simulation software coupled as a whole system and achieve highly accurate results.In order to complete the co-simulation, the contents of this thesis are as followings:Firstly, research papers about DFBM, SVPWM and slip-frequency vector control system are collected, and their working principles and implementation methods are studied.Secondly, on the basis of previous research, the formulation of dynamic mathematical model of the DFBM is derived and its simulation model in MATLAB/Simulink is established.Thirdly, based on the Simulink model of DFBM, the SVPWM and slip-frequency vector control models are added, and the whole system model is built in Simulink. Then, run the program, and obtain the simulation results, prepare for the realization of co-simulation.Finally, the DFBM model is established in the ANSYS Maxwell, and the slip-frequency vector control model is built in the ANSYS/Simplorer. Based on the rule of Co-simulation, the two separated software are connected, and the time-stepping finite element program is operated, the simulation results of the adjustable speed dragging system with DFBM are achieved.