A Five-Level Quasi Z-Source Based NPC Inverter for PV Applications

Abstract

—Latterly, impedance source based multilevel inverters are becoming popular for emerging renewable power generations. This paper presents a Five-Level quasi Z-source (qZS) based neutral point clamped (NPC) for photovoltaic (PV) applications. This inverter circuit is formed by integrating a dual quasi Z-source with a T-type arm and a diode clamped arm. Compared to the existing impedance source based NPC type converters, the proposed topology has less number of switching devices and reduced voltage stress. The level shifted pulse width modulation (LS-PWM) with hybrid shoot-through technique is implemented to achieve high boost gain and reactive power capability. The performance of the proposed topology is examined through simulation results for input voltage changes and load changes.