Current Limiting Characterization by Winding Types in Superconducting DC Circuit Breaker

Currently, power semiconductors (IGBT, Thyristor, etc.) are used for the stability and high reliability of DC system operation. However, we have proposed a current limiting DC circuit breaker with superconducting winding to improve the stability of the DC system. This is superior in terms of fast cut-off speed and economy of power semiconductors, and is suitable for changes to the Point to Loads DC system that will be expanded in the future. A superconducting DC circuit breaker is a model in which a superconducting current limiter and a DC circuit breaker are combined. The superconducting fault current limiter uses a superconducting wire made of GdBCO material to limit the initial fault current to lower the current level of the fault current, and the DC circuit breaker blocks the reduced fault current from the superconducting fault current limiter by configuring a mechanical cutoff switch, passive elements L, C and SPD. In this paper, this superconducting DC circuit breaker model was designed and tested by giving two variables, and the operating characteristics were analyzed. The first is the superconducting wire connection method, and the second is the power supply voltage. In addition, the initial fault current, the time when the zero point of the fault current is generated, and the time when the shutdown is completed were compared and analyzed. As a result, it was confirmed that the helical type showed a higher current limiting rate than the spiral type, and the result of reaching a fast current zero point was confirmed.