| Abstract |
A DC fault will propagate quickly in a DC grid and results in significant DC voltage drop and largecurrent increase. To protect the DC grid from the DC faults, the concept of hybrid HVDC circuit breaker(DCCB) is widely-accepted due to its low conducting loss and fast operation speed. The unidirectionalDCCB recently is considered to fulfil the protection criteria. However, for a well-built DC grid, amassive number of unidirectional DCCB will be applied. This will lead to the high capital cost. For aterminal applied multiple unidirectional DCCBs, their MOVs could be shared to reduce their capitalcost. The dual-circuit DCCB is proposed to reduce the size of MOVs by 50\% based on the idea ofsharing MOV. And the performance of the DC fault blocking is maintained. The structure and operationprinciple of the dual-circuit DCCB are introduced. Comparing with the unidirectional DCCB, the faultblocking capability and the economy of the dual-circuit DCCB is verified. |
