A CSI-7 Inverter for Low Voltage DC Source Photovoltaic Applications Using a Cockroft Walton Voltage Doubler Based DC-link

Photovoltaic applications have broadened their scope in recent years, integrating novel forms of control such as Distributed Maximum Power Point Tracking (DMPPT). In this instance, we can face the possibility of having a panel configuration that outputs a DC voltage that requires a significant boost since inverters are connected to fewer panels at a time to maximize power extraction. This paper presents a three-phase transformerless topology of the Current Source Inverter (CSI) aimed at providing both the necessary voltage boost and good power quality at the output by taking advantage of the typical characteristics of the CSI-7 inverter. A tri-logic SPWM strategy has been adapted to the seven-switch topology via a specifically designed logic gate array.