Three-phase transformerless grid connected Quasi Z-Source Inverter for solar photovoltaic systems with minimal leakage current

Abstract

We present the design of 3-phase transformerless grid connected Quasi Z-Source Inverter with minimal leakage current, suitable for application in solar photovoltaic systems. A modified space vector pulse width modulation technique with a reduced number of commutations per sector was used to minimize the leakage current without adding extra circuitry (filters and/or leakage current isolation/bypass circuits) in a transformerless Quasi Z-Source Inverter. Theoretical analysis of the proposed system is presented in detail and verified using Matlab Simulink®.