Publication

Abstract : This paper proposes a fuzzy logic based optimal tip speed ratio controlled maximum power point tracking for grid connected variable speed wind energy conversion system. The general system includes a three bladed fixed pitch turbine, permanent magnet synchronous generator (PMSG), three phase uncontrolled rectifier, DC boost chopper, PWM inverter and fuzzy logic controller (FLC). The PMSG is modelled in dq–synchronous reference frame theory. The combination of uncontrolled rectifier and DC chopper is employed to acquire the maximum power by controlling the generator. The dc output voltage of the boost converter is converted into ac voltage by PWM inverter. Fuzzy logic controller is applied to both grid side converter for grid voltage control and generator side converter for optimal tip speed control. Grid side controller is employed to vary the modulation index of PWM inverter to keep up constant grid voltage and generator side controller is utilized to stay up the tip speed ratio at an optimal value to operate the system at maximum power point. The effectiveness of the proposed system is verified through extensive simulation results using MATLAB/SIMULINK environment.