A multilevel PWM inverter topology for photovoltaic applications

A multilevel pulse-width modulated (PWM) single phase voltage-source inverter topology for photovoltaic applications is discussed in this paper. The use of the phase opposition (PO) carrier disposition multicarrier PWM switching technique for this topology is presented. Inverter switch control signals are derived. A 5-level and a 3-level PWM voltage waveform across the load is generated, for high and low modulation indexes respectively. Performance characteristics including total harmonic distortion for a range of operating conditions of the inverter are provided. Theoretical considerations discussed in this paper are supported with simulation and experimental results taken from a low power laboratory prototype.