Design and Development of Solid-state DC Circuit Breaker

As DC power is now being promoted due to its various advantages over AC power, it is more suitable to have a DC grid instead of converting DC to AC for consumption due to the increase of DC generating sources. However, there are challenges regarding the control and stability of DC power. DC circuit breaker has been actively studied in this regard. There is a risk of severe damage due to the mechanical nature of conventional circuit breakers. Most conventional solid-state DC circuit breakers cannot perform the operating duty and are not economical because more SCRs are required. This research paper proposes a solid-state DC circuit breaker with low conduction loss, quick reclosing and rebreaking capability. The circuit breaker can interrupt and clear the fault in around 200 µs; thus, it can reduce the chances of damage a lot more than mechanical circuit breakers. The operating modes and characteristics of the proposed circuit breaker are verified by Simulink/MATLAB simulation. Hardware implementation of the circuit breaker is carried out and results are presented. The circuit breaker is not only capable of breaking the current, it is also able to recharge the commutation capacitor for rebreaking. It means it has a rebreaking capability which the other available DC circuit breakers lack. The operating time of circuit breakers should be fast enough to prevent severe damage and electrical losses. Fast operating time also enables the use of lower-specification components in the circuitry.