Experimental performance evaluation of SiC BJT and Si MOSFET for 1.2 kW 300 kHz boost converter as a solar PV pre-regulator

Abstract

In this paper, a 1.2 kW DC-DC boost converter as a solar photovoltaic pre-regulator is designed to form the basis towards a comparative performance evaluation between similar ratings of 1200 V SiC BJT and Si MOSFET. The heatsink temperature and the measured switching waveforms are then compared by increasing the switching frequency up to 300 kHz and the case temperature up to 150 °C via a high temperature testing setup. Much faster turn-on switching time for SiC BJT, compared with Si MOSFET leads to reduced turn-on switching losses, and consequently the heatsink temperature at 300 kHz reaches only at 53 °C without external cooling such as a fan. For switching performance with case temperature variation, SiC BJT switching waveforms are temperature independent up to 150 °C case temperature. On the other hand, for Si MOSFET turn-on switching time gets faster as the case temperature increases.