Thesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Electrical Power and Machines

In this thesis a Quasi Impedance Source Inverter - QZSI fed from wind energy conversion system for isolated loads is designed. The impedance network coupling the source to the inverter bridge allows boosting the input voltage through utilizing shoot-through states. The desired line voltage at the inverter's output is achieved through a single conversion stage, instead of the mandatory additional conversion stages associated with the conventional inverters. The Space vector Pulse Width Modulation - SVPWM switching method is modified for intentional shoot through generation. The introduced system consists of a wind turbine, a permanent magnet synchronous generator (PMSG); a three phase uncontrolled rectifier, the QZSI and LC passive filter. A detailed design procedure for the rectifier, impedance network, the voltage source inverter and the passive LC filter is carried out. The rotational speed of the PMSG changes as the wind speed changes which results in changes in the generator and the rectifier output voltage. So, a PID controller was designed to regulate the DC link voltage. The amplitude and frequency of the output voltage are controlled by the modified space vector pulse width modulation technique (MSVPWM). A wind turbine emulator based on a torque controlled separately excited DC motor is implemented to emulate the torque/speed characteristics of the wind turbine providing the PMSG with the mechanical power extracted from the wind kinetic energy

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