| Abstract |
Recent studies have pointed out the benefits of using Silicon Carbide (SiC) devices in photo-voltaicpower conversion. In Particular, SiC Power MOSFET technology has greatly advanced over the lastyears and has presently reached sufficient maturity to stimulate a concrete interest in the developmentof power conversion circuits based entirely on this technology, in view of the clear potentialadvantages it offers over alternative SiC device technologies (e.g., JFET, BJT). This paper presents athorough characterization of an all SiC MOSFET based single-phase bi-directional switched neutralpoint-clamped (BSNPC) three level inverter, in which, for the first time, SiC Power MOSFETs ofdifferent voltage ratings (1200 and 600V) are used. A parametric experimental characterization of thepower cell performance is carried out, separating the effects of output power, heat-sink temperatureand switching frequency and load variations by means of bespoke heat-sink design. The effect ofrelying exclusively on the MOSFET body-diode for inductive load current freewheeling is criticallyassessed against usage of an external SiC Schottky diode. The experimental results are compared witha mixed approach design, where Silicon (Si) devices are used for the lower voltage switches and SiCMOSFETs are kept for the higher voltage ones, deriving a clear indication of the superior possibilitiesoffered by SiC Power MOSFETs for improved efficiency, power density and reliability, key aspects ofpower electronics technology evolution. |
