Novel Fault Control Scheme, Topologies and Communication-Assisted Protection Scheme for Multi-Terminal MVDC Distribution Networks

In this paper, a communication-assisted protection scheme for multi-terminal MVDC distribution networks that are configured with fault-handling converters is proposed. MVDC distribution networks are a good way to interconnect DC based distributed generations, but they pose a challenge for protection system design because of the power semiconductor switch based converters that are susceptible to overcurrent. To address this challenge, fault-handling converters which can control or tolerate fault characteristics of DC power system are introduced. Topologies and fault control scheme of fault-handling converters are proposed in this paper. Simultaneously, a communication- assisted protection scheme is proposed for faulted section selection. In proposed scheme, each protection device exchanges fault direction signals with its neighbors through communication links to distinguish between internal and external faults. The EMT simulations using Simulink with Simscape Electrical Toolbox are performed to verify the feasibility of proposed method.