Modulation and control of transformerless boosting inverters for three-phase photovoltaic systems: comprehensive analysis

This paper examines the performance of three power converter configurations for three-phase transformerless photovoltaic systems. This first configuration consists of a two-stage DC-DC-AC converter comprised of a DC-DC boost chopper and a three-phase voltage source inverter. The second and third configurations are the single-stage quasi-Z-source inverter (qZSI) and the split-source inverter (SSI). The performance of the presented topologies has been analyzed and compared in terms of topological requirements, modulation techniques, and control of output voltage, considering both ideal and parasitic cases. Moreover, the voltage and current stresses on the devices, passive elements, and efficiency are also addressed. Simulation and experimental testing were subsequently carried out to validate the analysis and evaluate the performance of the proposed topologies.