A Black Start Strategy based on Multiport Interlinking Converters for DC Microgrids

This paper presents a Black Start (BS) strategy for DC microgrids (DCMGs) to enhance the resilience of AC/DC hybrid distribution systems during blackouts. The proposed architecture utilizes multiport interlinking converters (MICs) to interconnect multiple DCMGs, which can act as local BS units to enable flexible boundaries of DCMGs. In the proposed control strategy, two operating modes can be realized, including grid-forming mode and grid-feeding mode, which can enable bottom-up power restoration and islanding operation of DCMGs. The BS approach involves a sequence of power restoration actions to reenergise DCMGs through local BS units, achieving dynamic reconfiguration of off-grid DCMGs. Simulation and experiment are implemented to validate the effectiveness of the proposed architecture and black start strategy.