Distributed Price-Based Power Management for Multibuses DC Nanogrids EEMS

Abstract

Nanogrids for single consumers have gained importance based on the development of standards for prosumers’ electrical installations (PEIs) such as the IEC 60364 series. All distributed energy resources (DERs) are usually integrated into a single place using one or more dc buses to reduce power conversion losses in those systems. Also, an electrical energy management system (EEMS) is required for the nanogrids smart operation, where droop controls and state machines have been considered for power management. The drawback of these strategies is that the power management is poor when droop controls are considered at the second layer because all DERs must contribute to the dc bus voltage regulation. In addition, the state machines are limited due to their reduced flexibility. The main contribution of this article is a distributed price-based power management (d-PBPM) proposed to overcome these challenges. The d-PBPM is based on dc bus signaling and the price theory, and no droop control is required in the second layer, improving the management efficiency. Experimental results show that the d-PBPM makes the nanogrids’ EEMS scalable to new DERs and new dc buses, considering the addition of distributed sources, dc buses, and energy price to an existing nanogrid. The experimental setup includes a dual dc bus nanogrid with photovoltaic (PV) systems, energy storage, loads management, and ac grid interface.