A novel PWM multilevel inverter for PV application

Abstract

In this paper, a single-phase five-level PV inverter topology for grid-connected photovoltaic (PV) system with a novel PWM control scheme is presented. PWM signals were generated by comparing two reference signals identical to each other with an offset equivalent to the amplitude of the triangular carrier signal. A digital PI current control algorithm is implemented to keep the current injected into the grid sinusoidal and to have high dynamic performance with rapidly changing atmospheric conditions and low THD. This new configuration of the proposed inverter is implemented in a prototype.