Research On Speed Control Technology And Application Of Brushless Doubly Fed Machine

With the continuous development of China's irrigation pumping industry,some problems in the regulation of irrigation pumping conditions have been exposed,When the demand of pump head and flow rate change greatly,The regulation of pumping station can not run in the best efficiency area,appearing large power consumption and low operation efficiency.brushless doubly fed machine is a kind of motor with stable operation and adjustable power factor,The most distinctive feature is that a part of the energy of the rotor can be fed back to the power grid,saving energy,Secondly the brushless doubly fed machine can be modulated by the magnetic field of the rotor,transferring energy by the original two uncoupled on the stator and rotating magnetic field with different poles,Removing slip rings and brushes to improve the stability of the motor.The brushless doubly fed Speed control technology is introduced into the operating regulation of irrigation pumping station can improve the efficiency of pumping stations,saving costs.In this paper,the development history and research status of brushless doubly fed machine are introduced,the structure and operating principle are described,building brushless doubly fed machine model in d-q coordinate system,MATLAB simulation software is used to simulate the different operating states of brushless doubly fed machine,Theoretical verification the feasibility of Brushless Doubly Fed Speed Regulation in pumping station,studying the relationship between the voltage amplitudeof the control winding,frequency and power factor,making the brushless doubly fed machine running in the best condition.In the traditional brushless direct torque control(DTC),the hysteresis width of torque and flux leads to the pulsation of the motor,reducing the Stability of brushless doubly fed machine.In this paper,a direct torque control strategy based on voltage space vector is introduced,Selecting appropriate amplitude and t appropriate control winding angle to drive SVPWM controlling brushless doubly fed machine.The MATLAB simulation software is used to simulate the two control methods of direct torque,Analysis the advantage of spatial voltage vector direct torque.Finally,this paper introduces the basic situation of the application of brushless doubly fed machine in the five level of Xi xi station,Combining the results of theoretical calculation and field test data,this paper analyzes the advantages of Brushless Doubly Fed Speed regulation Technology relative to water saving regulation,This paper analyzes the economy of the brushless doubly fed adjustment,Summing up the effect of Brushless Doubly Fed Speed Regulation in pumping station,and applies the brushless doubly fed speed regulation technology to the adjustment of the pump operating conditions.