Optimal and Decentralized Control Strategies for Inverter-Based AC Microgrids

Abstract

This paper presents two control strategies: (i) An optimal exergy destruction (OXD) controller and (ii) a decentralized power apportionment (DPA) controller. The OXD controller is an analytical, closed-loop optimal feedforward controller developed utilizing exergy analysis to minimize exergy destruction in an AC inverter microgrid. The OXD controller requires a star or fully connected topology, whereas the DPA operates with no communication among the inverters. The DPA presents a viable alternative to conventional P − ω / Q − V droop control, and does not suffer from fluctuations in bus frequency or steady-state voltage while taking advantage of distributed storage assets necessary for the high penetration of renewable sources. The performances of OXD-, DPA-, and P − ω / Q − V droop-controlled microgrids are compared by simulation.

Keywords

• DC power system
• AC power system
• optimal control
• decentralized control
• distributed control
• microgrid
• power system control