Power electronic interfaces for ultra available dc micro-grids

This work quantitatively evaluates the effect on dc micro-grids availability of both conventional architectures with single-input converters and alternative configurations with multiple-input converters. The analysis indicates that use of diverse power sources is essential in order to achieve high availability levels. Calculations yield that multiple-input converter configurations achieve availabilities that are roughly equal or better than those using single-input converters. Yet, the former require fewer components than the latter. Three converter topologies are used in the study: boost, isolated SEPIC, and current-source half-bridge. Among the multiple-converter topologies evaluated the boost multiple-input converter yields the maximum availability. However, Although the isolated SEPIC leads to an availability only marginally below the highest one achieved by the boost, it provides significantly higher operational flexibility because it can achieve high voltage conversion ratios and track the entire output range of sources in search of a maximum power operating point.