Surge Current Capability of SiC JFETs in AC Distribution Systems

Growing commercialization of SiC JFETs with low conduction losses is enabling their potential in non-traditional application spaces such as AC switchgear and controlgear. However, a key performance requirement such as surge current capability of these devices in AC circuits is generally not provided by their manufacturers in product documents. This paper presents the experimental validation of surge current capability of selected SiC JFETs for low voltage AC distribution system applications. Because AC electrical apparatus, such as power relays, contactors, and circuit breakers, have a different set of system parameters and requirements compared to traditional power converter applications, power semiconductor devices need to be validated for a different set of system requirements. In fact, robustness to inductive short circuit currents, inrush currents, short and long-time overload are some of the basic requirements for the utilization of WBG devices for these applications. In this paper, we compare the performance of different SiC JFETs under different types of AC waveform conditions.