Coordinated Control Research Of Back-to-Back Converter Based On Double-fed Wind Power Generation System

The traditional energy shortage problem and the ecological environment pollution problem brought new challenge,the new round clean energy technology innovation and the industrial change is forming,but as one of the clean energy power generation technology important constituent,the wind power generation technology receives the domestic and foreign scholar's widespread attention.as one of the main power generation forms in the market,doubly-fed wind power generation is widely used because of its small excitation capacity,good dynamic performance,smooth grid-connected and low cost.The rotor side converter undertakes the vector control task of doubly fed motor,the network side converter completes the energy exchange with the rotor and the rotor side converter and the power grid through the DC bus,so the stable operation of DC bus is very important,in order to reduce the DC bus voltage fluctuation,the method of increasing DC bus filter capacitance is The introduction of high-capacity capacitance will reduce the security and reliability of the whole system.This paper presents a coordinated control strategy using dualPWM converters.This article first detailed analysis of the wind turbine operating characteristics,the maximum wind energy capture method and doubly-fed induction motor speed regulation principle,and the abc static and dq The mathematical model of the rotating coordinate system is constructed.on this basis,a rotor PWM converter control model is built with the topology structure of the rotor side PWM converter,and the double closed loop vector control strategy with the internal loop current inside the rotational speed is used,The decoupling control of the stator output active reactive power and the maximum wind capture control are realized.Secondly,about grid side PWM With the analysis of the topology and mathematical model of the converter,the double closed loop control of the voltage outer loop current inner loop is established,which realizes the unit power factor operation of the network side PWM Converter and the steady running of the DC bus voltage.Finally,delve deeply into the rotor side PWM converters and grid side PWM a new dual PWM converter coordinated control strategy of load current feedforward is proposed,which is to introduce dynamic information of load current in the network side PWM converter voltage control loop,in the Matlab/simulink to build a complete double PWM the simulation model of doubly-fed wind power generation system controlled by the converter coordinated control strategy is compared with the independent control strategy and the DC bus voltage fluctuation under the coordinated control strategy,which verifies the correctness and superiority of the coordinated control strategy,which effectively suppresses the fluctuation of DC bus voltage.Improve the security and stability of the system.