With world electricity activity growing steadily, the demand for renewable energy sources is also expected to increase drastically. Wind, a free, clean, and inexhaustible source of energy, is increasingly competitive with other energy sources.Variable speed wind turbines are known to provide more effective power capture than fixed speed wind turbines. However, the grid is set at a fixed frequency at most loads. The voltage source inverter (VSI) with a DC chopper circuit has traditionally been used for this voltage level and frequency conversion. The traditional VSI, however, has the limitation of only providing output voltages that are lower than input voltages. For this reason, the DC chopper circuit is used to add a boost feature. Even though this topology is functional, the extra active devices and controls add additional system costs and complexities. Alternatively, the Z-source inverter presented recently not only overcomes the voltage limitation of the traditional inverter, but also uses fewer components. Moreover, it is more efficient and reduces cost. As a result, it is well suited for wind turbine systems. This dissertation presents the application of the Z-source inverter for wind power systems. The operational principle and control method of the proposed system are herein explained in detail. Simulation and experimental results are provided in order to verify the validity of the developed wind turbine generation system.
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