Limitations and improvements in Impedance Source Inverter Topologies

A survey of different topologies on impedance source converter has been described in this paper. Besides of merits and demerits modifications in topologies are described. A comparison in terms of inrush current, voltage stress on capacitor and devices, gain in voltage and components needed is mentioned. All these parameters, comparison and topology make the use of converter for a particular industrial application. The ZSI (Impedance source inverter) has a L-C network which provides a link between DC source and 3-phase VSI which makes it different from other kinds on converter. This is the main structural feature of ZSI as compared to conventional VSI (Voltage source inverter) and CSI (Current source inverter). The impedance source inverter overcome the academic, realistic and intangible barrier and restrictions of the conventional VSI and CSI converter and provides a innovative based conversion of power. The ZSI model can be apply to all conversion stages. The development of solar based photo voltaic cell and wind energy sources demands to increase large gain variety converters. The impedance source inverter implemented to overcome the drawbacks of existing converters. Impedance source inverter can step up, step down and convert power in one stage structure with no extra active switches with the advantage of easy control technique. However, this converter subject to several disadvantages likes voltage stresses and large size impedance network. Several researchers have concentrate their focal point to get better (ZSI) by satisfying these gaps. Paper shows all-inclusive study of (ZSI) topology and their modifications for a variety of applications. In this paper author identify the various draw backs of impedance source inverter like voltage stresses on IGBTs switches, large inrush current at starting, large size and complicated impedance network. To overcome all these difficulties a survey of voltage gain comparison of different topologies with PWM technique has discussed.