Study On Vector Control For Doubly-Fed Induction Generator

VSCF AC excitation doubly fed wind energy generation system and its control technology is studied in this paper.In this paper,basic principles,control technology and LVRT ability of Doubly-Fed Induction Generator are given, Summarizes the characteristics and advantages of DFIG in VSCF.The key techniques and realization methods of control target,control mode,operational characteristic and system power floating of grid-connected dual PWM converter VSCF DFIG are mainly studied, and the rotor-side converter control system,grid-side converter control system,power control system are designed in this paper. Analysis of the drawbacks of the conventional PI control,it can use a fuzzy power control to overcome it.Using MATLAB the simulation model of9MW VSCF doubly fed wind power generation system is built,the simulation of the interconnected performance characteristic of VSCF under the proposed control strategy is conducted. Simulation results show that it can achieve active decoupling control of reactive power under the grid,and adopte maximum wind energy capture control,it realizes that Generator can be achieved safe and convenient grid, guarantee the stable operation of wind power generation system. Proved by MATLAB simulation in the case of wind speed is a random variable,the fuzzy control technique can provide better damping than the PI control, and the voltage,power of the system are more stable.Summed up the program of LVRT.The drawbacks of traditional control techniques to design the rotor current ADRC controller base to achieve LVRT. For the LVRT (Low Voltage Ride Through) of DFIG (Doubly Fed Induction Generator) set,the grid-connection requirements for wind power generation during grid voltage dip is introduced,several existing strategies are analyzed and a corresponding control strategy is proposed.For the deep and short voltage dip,the Active Crowbar and DC dumping circuit are controlled by the hysteresis loop of rotor current and DC voltage to dump the superabundant energy, protect the power converter and maintain the grid-connection of DFIG Simulative results prove the proposed control strategy suppresses the rising of rotor current and DC voltage and supports the reactive power to grid satisfactorily.