Abstract

Multi-port hybrid DC circuit breaker (MPHCB) is considered to be the most suitable device to protect the DC grid and can solve the problem of high cost of DC circuit breaker (DCCB) and promote its large-scale use in dc grid. At present, many MPHCB topologies include load commutation switches (LCS), which have the problem of large losses. This paper first proposes an MPHCB using negative voltage source (NVS). By analyzing the short-circuit current and the commutation auxiliary device needs to provide commutation current, the pre-charged capacitor is designed with detailed parameters, which provides a theoretical basis for parameter selection. Secondly, the effectiveness and applicability of the proposed MPHCB under different fault scenarios are verified through simulation. Finally, the economics and functionality of the proposed MPHCB are compared with existing solutions to highlight the advantages of the proposed solution.