An Extended T-type (eT) Inverter Based on SiC Power Devices

The paper presents simulation and experimental study focused on a modified topology of the power converter-an extended T-type (eT) inverter designed and built with SiC power devices. It consist the standard three phase T-type topology with additional DC/DC converter connected across the DC side capacitors. The eT inverter shows high voltage gain and, in consequence, may be applied as an interface between three-phase grid and low voltage sources (i.e PV panels). Moreover, the DC/DC converter is capable to influence neutral point potential and necessary capacitance of the DC side capacitors is lower. Basic operation principles are explained and simulations on the 6 kV A laboratory model are shown. eT inverter is supplying resistive load with 3×400V RMS output voltage from 250 V DC source. Finally, a series of experiments of a laboratory model designed with SiC MOSFETs and Schottky diodes is also presented.