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A Self-Organizing Nano Grid (SONG) for Energy Access Clusters

Conference ·

In this paper, a bottom-up dc Self-Organizing Nano Grid (SONG) for rural electrification at ultra-low-cost through a flexible and scalable topology is presented. The proposed nano grid requires no communication and uses dc-bus signaling to convey excess energy in the system through the bus voltage, allowing independent agents to conduct energy transactions based on their needs in a decentralized manner. Moreover, this article proposes a concept that uses a novel multi-source, multi-segment droop control strategy with demand coordination, allowing for dynamic self-balancing of the system under fluctuating operating conditions. The unique use of a surplus photovoltaic (PV) power droop mode precisely estimates energy availability to minimize load chattering that helps in stabilizing the dc-bus. In addition, this architecture uses standard dc/dc converters for a low-cost, modular, Plug and Play ( PnP ) solution with highly automated operation, enabling local assembly, operation, and maintenance by non-technical personnel. The proposed SONG concept was validated in simulation and with a 700W, laboratory-scale, custom made nano grid system. The simulation and experimental test cases show the feasibility of the SONG system by demonstrating the proposed multi-source, multi-segment droop control strategy without load chattering under varying operating conditions.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE National Renewable Energy Laboratory (NREL); Georgia Institute of Technology, Center for Distributed Energy
DOE Contract Number:
AC36-08GO28308
OSTI ID:
1916441
Report Number(s):
NREL/CP-5D00-85104; MainId:85877; UUID:71ef7f62-45b2-4a46-a332-c23e85a587e7; MainAdminID:68528
Resource Relation:
Conference: Presented at the 2022 IEEE Energy Conversion Congress and Exposition (ECCE), 9-13 October 2022, Detroit, Michigan
Country of Publication:
United States
Language:
English

References (10)

Self-Organizing NanoGrid (SONG) conference February 2019
A Decentralized Control Architecture Applied to DC Nanogrid Clusters for Rural Electrification in Developing Regions journal February 2019
The National Solar Radiation Data Base (NSRDB) journal June 2018
A Decentralized Control Method for Distributed Generations in an Islanded DC Microgrid Considering Voltage Drop Compensation and Durable State of Charge journal December 2016
Enabling a Decentralized Smart Grid Using Autonomous Edge Control Devices journal October 2019
Challenges of Microgrids in Remote Communities: A STEEP Model Application journal February 2018
Distributed Cooperative Control of DC Microgrids journal April 2015
Implementation of Hierarchical Control in DC Microgrids journal August 2014
Online Energy Sharing for Nanogrid Clusters: A Lyapunov Optimization Approach journal September 2018
State of Charge Based Droop Control for Coordinated Power Exchange in Low Voltage DC Nanogrids conference July 2019