Simulation Research On Integrative Control Strategy For Voltage And Reactive Power Of Wind Farm

Recently, energy crisis becomes an increasingly serious problem, whichpromotes the rapid development of renewable energy. Especially, wind energy hasbeen greatly developed in the last decade. However, different problems turns upalong with the progress of wind industry, such as the integration and consumption ofwind energy, the voltage stability problem and control strategy of power gridintegrated with large-scale wind farms. This thesis emphasizes on the integrativecontrol strategy for voltage and reactive power of wind farm based on DFIG. We cansufficiently utilize the reactive power adjusting capacity of wind farm by effectivedesign, such that we can maintain the stable of voltage and simultaneously minimizethe power loss of wind farm. We verified the validity of the proposed control strategyby simulation under MATLAB/SIMULINK. The main research contents of this thesisincludes:(1) The mathematical model of DFIG and PWM were established, and powercharacteristics of DFIG was analyzed. We deduced the limitation of reactive powerfor DFIG which laid a theory foundation for the later research on control strategy.(2) We studied the basic control strategies of DFIG and then researched on threedifferent control strategies of reactive power for DFIG depending on various controlaims. Based on this, we proposed the integrative control strategy for voltage andreactive power of wind farm, and indicated its merits.(3) We used MATLAB/SIMULINK to simulate different control strategies ofreactive power for wind farm depending on various control aims. We also presentedthe meaning of the proposed control strategy by horizontal comparison.