THIPWM technique applied to three level ANPC converter for grid tied PV applications

Abstract

In recent years, the majority of the research has focused on grid-tied transformerless PV inverters, more capable than traditional grid-tied line transformer-based PV inverters, but more critical from a power quality point of view, especially in terms of common mode voltage and ground leakage current. Neutral point clamped (NPC) converters have recently gained popularity due to high efficiency and inherently low ground leakage current. This paper presents the three level active NPC (3L-ANPC) topology for grid tied PV applications with a third harmonic injection PWM strategy that allows to increase the magnitude of sinusoidal modulating wave by 15.5 % which improves dc link utilization. Simulation is carried out in Matlab/Simulink environment which confirms the effectiveness of the proposed converter.