Cost-prioritized droop schemes for autonomous microgrids

Droop schemes for parallel source control usually aims for proportional power sharing tuned in accordance to the source ratings. This works fine for sources with close similarity, but not really for an autonomous microgrid where different types of Distributed Generators (DGs) may be present without centralized optimal dispatch control. To better adapt to this non-uniformity, an alternative viewpoint based on reducing the Total Generation Cost (TGC including fuel cost, emission penalty and other operational concerns) of the microgrid is discussed, from which two new cost-prioritized droop schemes are developed. The schemes operate by tuning the dispatch priorities of the DGs and curve shapes of their resulting active power versus frequency plots. Their effective reduction of TGC has been verified through simulation.