An Optimized Distributed Cooperative Control to Improve the Charging Performance of Battery Energy Storage in a Multiphotovoltaic Islanded DC Microgrid

Abstract

When multi-photovoltaic (PV) energy sources are installed in dc microgrids (DCMGs), an optimized distributed controller is essential to provide efficient, economical, and reliable operation. This article proposes an optimized distributed cooperative control method for multi-PV energy sources in an islanded DCMG. Unlike conventional control methods for DCMGs, the proposed distributed cooperative control method is capable of obtaining a constant total generated power from PVs, thus minimizing the impact of the intermittent nature of PVs on the total generation. This operation subsequently reduces the charging stress on the backup energy storage system (BESS) and increases the lifetime of the BESS in the DCMG. The proposed control method can also intelligently reduce the total generation cost of the DCMG via monitoring and analyzing the information of energy sources and minimizing the quadratic cost function. The dynamic model of the proposed controller is thoroughly analyzed, and its effectiveness in terms of providing controllable generated power and cost reduction is validated for different generation-demand scenarios.