DC Networks Including Multiport DC/DC Converters: Fault Analysis

DC networks that include storage systems, renewable sources, dc loads, and front-end converters can provide some advantages as compared with ac grids. However, the interruption of fault currents is difficult due to no-zero crossing of the current. Moreover, the fault clearing time of traditional dc circuit breakers can be too long for protecting power electronics switching components. Multiport converters seem to be a good solution for solving the aforementioned problem. The introduction of a multiport dc/dc converter, along with its configuration and a centralized control for power flow management, is proposed in the initial sections of this study. After this, this paper focuses on the study of system behavior during fault functioning conditions. Both pole-to-pole and pole-to-ground faults are investigated. The authors propose some control strategies and hardware solutions to overcome dc protection issues during several fault types. Some numerical simulation results are provided.