Comparative analysis of conventional, FWZSI and ZSMLI based UPS systems

Abstract

The UPS systems always have the drawbacks such as higher switching stress, higher THD value and lower efficiency when normal inverters used. Four wire z-source inverter (FWZSI) and z-source multilevel inverter (ZSMLI) are proposed for UPS application to overcome these problems. A comparison is carried out between the proposed FWZSI and ZSMLI with the conventional power converters for UPS systems. The comparison is made based on voltage boost, dc link voltage, ripples in capacitor voltage and inductor current, voltage stress across power switches, power quality and power conversion efficiency . Also the shoot through pulse insertion in the four wire Z-source inverter and z-source multilevel inverter are compared and analyzed in detail. The performance of proposed and conventional power converters are compared for different values of input and output conditions. The results for each scheme are verified with the laboratory experimental set up [1], [2].