DC current suppression circuit in HVDC power transmission system

To increase the popularity of HVDC power transmission system, the Multi-Terminal Direct Current (MTDC) power transmission system is expected to be installed. Since the Voltage Source Converter HVDC (VSC-HVDC) is available, the MTDC systems are much more likely to be installed soon. However, an efficient Direct Current blocking measure such as DC circuit breaker remains as the most critical hurdle to implement MTDC system. In this paper, a new DC current suppression circuit is proposed. This circuit is a kind of the semiconductor DC circuit breaker, and can be used for very quickly interrupting the DC current against the short circuit fault condition at the cost of minimum conduction loss at the normal operation. Because of the modular configuration, the proposed circuit has inherent redundancy and no need of the series-connection of the semiconductor switches and bulky surge voltage arrestor bank.