Fault Protection Strategy for Multi-Terminal HVDC System by use of DC Circuit Breaker

The protection strategy for Multi-Terminal HVDC system by means of HVDC circuit breaker should be established before the commercial application of MTDC system. This paper aims to suggest a feasible protection strategy by means of HVDC circuit breaker in MTDC system. The analysis and establishment of zones of protection in MTDC system were preceded. Both numerical analysis and simulation study on the DC fault current in CIGRE B4.57 benchmark model were also progressed to determine the requirement for HVDC circuit breaker and its interrupting capacity. From the result, it was found that the suggested protection strategy has been ensured the performance as much as conventional protection strategy with hybrid dc CB.