Indian Journal of Science and Technology

Abstract

Background/Objectives: This paper analysis the various PWM controlling Techniques of Single Phase Z-Source Inverter (ZSI) and suggest the most suitable controlling technique for renewable power conversion applications. Methods/Statistical Analysis: This ZSI is the Buck-Boost Inverter. The boost in the output voltage can be controlled by Shoot-Through (ST) zero state. This ST zero state can be controlled by Simple Boost Control (SBC), Maximum Boost Control (MBC) and Constant Boost Control (CBC) methods. The performances of the controlling techniques are investigated against the simplicity in control technique, harmonic content and the peak value of output voltage. The controlling techniques are validated by simulation of the circuits in Simulink. Findings: The MBC method is the simplest one to implement but voltage stress across the switches is high. The CBC method gives a higher voltage gain but implementing the Shoot-Through envelope is difficult. In SBC method Voltage stress across the switches is less but voltage gain is less. The Photo Voltaic Energy conversion system requires high voltage gain with reduced harmonic content in the output. Therefore, the CBC method is suitable for the Solar PV system to provide higher voltage gain with less harmonic content in the output voltage. Application/ Improvements: The CBC method gives higher voltage gain with less harmonic content in the output voltage, therefore it is most suitable for the standalone Solar PV system.
Keywords: PWM, Shoot-Through, Voltage Gain, ZSI