PERFORMANCE EVALUATION OF Z-SOURCE INVERTER FED INDUCTION MOTOR DRIVE

Abstract

Many applications in the industries such as the Adjustable Speed Drives are based on the voltage source inverters which consists of diode rectifier front end, dc link capacitor and inverter bridge. But there are limitations associated with the traditional inverters. To overcome these limitations, we are introducing the Z-source inverter. The Z-source inverter is one of quite new ideas designated to renewable energy system, mainly fuel cell and photovoltaics. This Z-source inverter can be used for ac to ac, ac to dc, dc to do and do to ac conversions. Here in our dissertation we are going to discuss about the operational analysis of Z-source inverter, its comparison with traditional inverters. Different control strategies are also proposed for the Z-source inverter like the simple control, boost control, constant boost control, third harmonic injection control, modified space vector modulation technique. In our thesis we go in detail about all these control strategies and we compare different aspects like voltage gain, voltage stress and so on between these control strategies. The Z-source inverter fed induction motor with all the above mentioned control strategies are simulated. The output line voltages, the boosted dc voltages, induction motor torque, speed, rotor and stator currents, inductor current and capacitor voltages are observed in the various simulations developed.