A Reconfigurable Series / Parallel IGBT-Based DC Solid-State Circuit Breaker

Modern Direct-Current (DC) power systems operate with increased load demand as well as high system voltage. Ultrafast and reliable fault isolation is a necessity in DC systems due to the absence of natural current zero-crossing points and the rapid rise of fault current. This paper presents a modular reconfigurable DC Solid-State Circuit Breaker (SSCB) using two IGBT switches that can operate either in series, offering high voltage blocking capability, or in parallel for high current carrying capability. The key challenges in such a reconfigurable SSCB, such as unequal static and dynamic voltage balancing in series connection of switches and current sharing imbalance in parallel operation, are discussed. A hardware prototype of the reconfigurable SSCB rated at 400 V, 25 A is experimentally validated against overcurrent events, considering the series as well as parallel connection of IGBTs.