The Vector Control System Of Brushless Doubly-Fed Machine

First of all, the Brushless doubly-Fed Machine (BDFM) stator, rotor's structure and operation methods are introduced. It can realize asynchronous, synchronous operation or doubly-fed models. It can be used in AC adjustable-speed drive systems as a motor or be used in generating systems as a generator, which has good developing future.Secondly, the network, the rotor speed models are also introduced, and the double synchronous speed mathematical model has been deduced and set up in this paper. Firstly, the double synchronous speed mathematical model is established on the basis of rotor speed model, which divided BDFM into control winding and power winding sub-coordinate systems. In each coordinate system, the variations of stator and rotor are all changed into DC value, so the speed, the toque and the power can be controlled by voltage of the control winding, which founds the theoretic foundations for BDFM's control strategy and methods.And then, the proper quantities control of traditional induction machine is introduced simply. Study the basic idea of vector control, vector transform and the constitution of traditional induction machine's vector control system primarily and make out the theoretical basis for BDFM's vector control.At last, it researches the rotor flux oriented control system of BDFM, builds the power winding and control winding on separate synchronous reference frame, and orients flux separately, which simplifies the mathematical model. On the base of that the paper proposes a rotor flux oriented control strategy according to the dual-synchronous coordinate model, which can realizes the dynamic torque control. The simulation results indicate that this control method with perfect dynamic torque control performance is suitable for BDFM control system.