Simulation study of Permanent Magnet Synchronous Generator (PMSG) connected to variable speed Wind Energy Conversion System (WECS)

The presented work proposes a suitable power converter design for a Wind Energy Conversion System (WECS) connected to a variable speed Permanent Magnet Synchronous Generator (PMSG) for grid integrated operations. In the present work energy is derived from WECS and fed to the PMSG. Due to the non-uniformity of the wind velocities the voltage and frequency gained as output of the generator are variable quantities, so that it cannot be synchronized with the grid. The output of the generator is rectified using an uncontrolled three phase diode-rectifier and a constant value is achieved using a closed loop DC-DC converter. The controlled DC-DC Converter is designed using a PI controller based feedback control. Output voltage is continuously sensed and corresponding change in duty ratio of the switch maintains a constant DC-link voltage. The three-phase voltage source inverter (VSI) receives the output of the controlled converter. The inverter uses pulse width modulation (PWM) technique and its output is fed to a variable load which is connected to a grid. Simulation of proposed scheme is presented by MATLAB-Simulink model and the results demonstrate the validity of the developed model.