Research On Control System Of Wound Rotor Brushless Doubly-Fed Motor

With the 13 th Five-year Plan proposed,and on the background of advocating to improving the efficient of the energy,variable speed constant frequency technology has been sufficiently developed.The brushless doubly-fed motor has been widely used in wind power,hydropower since VSCF operation can be realized,and the desired drive capacity is small.Without brush and slip ring in structure of BDFM,and at the same time possessing excellent characteristics of synchronous and induction motors,Greatly improving the reliability during the motor operation,reducing maintenance costs later.The structure design of the two sets of stator windings enables the low voltage winding control high voltage winding to be realized,and has a very wide prospect in the field of high voltage speed regulation.Based on this background,this paper studies the control system of BDFM.In this paper,the basic principle of the brushless doubly-fed motor operation is introduced,and the internal power distribution relationship of the motor is analyzed,as well as energy flow in the case of motors and generators.The mathematical model of the brushless doubly-fed machine which is deduced under different coordinates.In the paper,The electromagnetic torque equation of the motor is obtained from in principle of internal energy conversion of brushless doubly-fed machine,then the power angle characteristic of the brushless doubly-fed motor is analyzed,and the voltage phase angle control strategy of the control winding voltage is proposed,the control system has little dependence on the motor parameters,but the dynamic performance can not meet the requirements of some industrial applications,so power winding magnetic field orientation vector control strategy is proposed.An adaptive compensation flux observer is proposed and a theoretical analysis is put forward based on the existing flux linkage observation method.The control strategy is modeled and simulated in Simulink environment,and the validity and feasibility of the control strategy are verified.The hardware circuit of the brushless doubly-fed machine control system is designed and the selection of the experimental device is completed.Finally,based on the 30 kW winding brushless doubly-fed motor,the experimental platform is completed,and the open-loop speed regulation and closed-loop speed control experiment,and the validity of the vector control strategy is further verified.