A Step-by-Step Approach for Replacing Si-IGBTs With SiC-MOSFETs Modules in Industrial Power Converters

Abstract

This work presents a step-by-step approach for replacing Si-IGBTs with SiC-MOSFETs modules in a 9-kW commercial double-conversion UPS. Incremental modifications are applied to the original system, considering variations in switching frequency and evaluating its influence on losses and total volume. Through the use of Si-IGBT transistors and redesigning the system, the volume and losses are analyzed for switching frequencies between 10 and 17 kHz. The IGBT showed limitations around 17 kHz, with high losses due to tail current. With SiC-MOSFETs, the switching frequency is increased, resulting in smaller filter volumes. The SiC module allowed operation at frequencies in the tens and hundreds of kHz, with relatively low switching losses, which significantly reduced the volume of filters and heat transfer systems. These technological advancements resulted in reductions of up to 78% in the total volume and improved efficiency, enabling operation at lower temperatures and potentially increasing the lifetime of components.