A Three-Phase Active-Front-End Converter System Enabled by 10-kV SiC MOSFETs Aimed at a Solid-State Transformer Application

• Published in: IEEE transactions on power electronics 2022-05, Vol.37 (5), p.5606-5624
• Main Authors: Anurag, Anup, Acharya, Sayan, Kolli, Nithin, Bhattacharya, Subhashish, Weatherford, Todd R., Parker, Andrew A.
• Format: Article
• Language: English
• Subjects: Active-front-end converter (AFEC) system; Busbars; Control systems design; gate driver; High voltages; Inductors; Insulated gate bipolar transistors; Logic gates; Medium voltage; medium voltage (MV); Modules; MOSFET; MOSFETs; Power transformer insulation; Semiconductor devices; Silicon carbide; silicon carbide (SiC) devices; solid-state transformer; Voltage; Voltage converters; XHV-6
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2021.3131262

The use of high-voltage silicon carbide (SiC) devices can eliminate multilevel and cascaded converters and their complicated control strategies, making converter systems simple and reliable. A three-phase two-level voltage-source converter system serves as a simple converter system for interfacing any dc source to a three-phase grid. However, when the high-voltage devices are used in two-level converters, they are exposed to a high-voltage peak stress and a high dv/dt (up to 100 kV/\mus). Operating these semiconductor devices at these stress levels requires careful design not only of the semiconductor die and the module, but also of the gate drivers, busbars, and passive filters. This article demonstrates the operation of 10-kV SiC mosfet s and discusses the design considerations, advantages, and challenges associated with the operation of the three-phase two-level medium-voltage converter system used as the active-front-end converter system. Reliable operation of the medium-voltage converter system requires the development of reliable high-voltage modules and auxiliary parts, such as gate drivers, busbars, inductors, voltage and current sensors, and proper design of the controller system. Successful tests demonstrating continuous field operation of the medium-voltage active-front-end converter at a nominal rating of 7.2-kV dc-link voltage is demonstrated for the first time in the literature. The results indicate that these devices can accelerate the growth and deployment of medium-voltage SiC devices for field operation, as demonstrated by the operation inside the mobile container.