Stochastic Distribution Controller for Wind Turbines with Doubly Fed Induction Generator

Abstract

The major purpose of this work is to design the controllers for controlling thevariable speed, variable pitch wind turbine (WT) with doubly fed inductiongenerator (DFIG). Vector control strategy is adopted for controlling theDFIG active and reactive power. Generator torque is control to provide theregulated real power with minimum fluctuation. The fixed gain proportional-integral (PI) controller designed to the converter of rotor side and gridside has limited operating range and inherent overshoot. Gain schedulingPI controller is designed to minimize the overshoot and fluctuation existsin proportional-integral controller. Since DFIG based wind energy conver-sion system (WECS) works in uncertain wind speed, stochastic distributioncontrol (SDC) method is proposed to control the probability distributionfunction (PDF) of DFIG based WECS. It copes with nonlinearities in theWECS and contiguous variations at operating point and provides satisfactoryperformance for the whole operating region. It improves the performancetogether with power quality of generated electric power thereby maximizing the lifespan of installation and ensures secure and acceptable operation of theDFIG based WECS.