Arc analysis for the interlinking AC/DC buses in hybrid AC/DC building microgrids

Abstract

The utilization of distributed generators, renewable energy, and energy storages boosts the microgrid development. Among various microgrids, the building microgrid (BM) tightly related with our daily life is also experiencing the improvement. One of the most obvious changes for the BM is the penetration of DC sources and DC loads, which forms the hybrid AC/DC BM. Because of the relatively small space and people density, the arc hazard should be paid more attention for buildings. In the meantime, the development of hybrid AC/DC BM will make the arc analysis more complicated, in which the AC and DC sections are closely interlinked. As the core interlinking part, the interlinking AC/DC buses are important to the safety guarantee of the hybrid AC/DC BM, which requires the main concern in the arc analysis. For the safety maintenance, this work firstly analyzes the hybrid AC/DC BM. Based on the arc current and the incident energy, an arc analysis flow is then designed for the interlinking AC/DC buses. Through the respective analysis for the interlinking AC and DC buses, a linear relationship is detected between the AC/DC loads and the arc current as well as the incident energy. By comparisons between the interlinking AC bus and DC bus, the qualitative and quantitative results are also illustrated for their arc differences. With the larger value, the increasing ratio of DC arc current could be employed as the detection signal. As larger loads cause larger arc current and incident energy, distributed loads are preferred to aggregated loads.