Fault Clearance Solution for Flexible DC Grids Based on Capacitive DC Circuit Breakers

The high equipment costs associated with key components like DC circuit breakers (DCCB) and fault current limiters (FCL) pose a significant challenge. In response, this research introduces a novel circuit breaker topology utilizing capacitors as both current limiting and interrupting units, accompanied by a comprehensive fault clearance strategy tailored for diverse DC fault scenarios. Moreover, the study conducts an in-depth analysis of the interdependencies between voltage and current stresses in fault clearance solutions, energy dissipation in surge arresters, and the relationships with system and circuit breaker parameters. This analysis provides valuable insights for designing circuit breaker parameters. The proposed circuit breaker's fault interruption capabilities are rigorously validated through simulations using PSCAD/EMTDC. Results affirm the swift fault clearance capability of the proposed solution, with the added advantage of lower economic costs when compared to existing DCCB alternatives.