Overload Comparison of STATCOMs Using 3.3kV Si-IGBT and SiC-MOSFET Power Modules

The overload capability of chain-link MMC based STATCOMs using two different power modules of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.3 \text{kV} / 450 \mathrm{A}$</tex> SiIGBT and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.3 \text{kV} / 500 \mathrm{A}$</tex> SiC-MOSFET, both housed in the same LinPak package, are comprehensively evaluated. Three critical indicators, namely overload factor, overload margin and overload duration, are used to fully assess the system overloadability, considering variables including grid-connection voltage, transmission power level, and switching frequency. Besides, several critical device-level prerequisites including SOA, thermal limits, turn-on/off losses and conduction losses that are obtained through lab tests will also be presented. The systematic evaluation proves that the STATCOM using SiC MOSFET has the benefit of a substantially stronger overloadability compared to that using Si IGBT.