Background

A Direct Current (DC) microgrid is a localized power system that can run independent of the main power grid by generating and utilizing its own DC power. Because they are decentralized from the power grid, DC microgrids are a highly useful means of managing localized electricity demands. DC microgrids can be used in multiple scenarios, such as disaster response, military field construction, or emergency backup system applications.

At its core, a DC microgrid is a collection of power supplies and power consumers, all connected by various physical cables to create the grid. The exact nature of these connections create the grid’s architecture. The resulting architecture dictates the current sharing accuracy, construction cost, maintenance requirements, and other characteristics of the DC microgrid. The two main goals of any microgrid architecture are decentralization, which allows the grid to continue functioning even after damage, and accurate current sharing to all loads across the grid.

The two most prevalent DC microgrid architectures currently in use are Ring and Mesh architectures. Unfortunately, neither of these accomplishes both of the above goals very well, but rather, both have significant disadvantages. Thus, there is a need for a more robust architecture that can increase the performance characteristics of DC microgrids.

Technology Overview

NC State researchers have developed a novel mesh-based architecture for DC microgrid control that substantially improves a grid’s characteristics over other currently available options. This architecture captures the advantages of both Ring and Mesh architecture, while avoiding their disadvantages. It achieves both accurate current sharing across the grid and multiple redundancies to prevent grid outages in the event of damage.

This architecture is the best of both worlds and demonstrates substantially improved DC grid performance characteristics over the prior art.

This architecture has been validated in simulations and is currently being tested in physical hardware.

Benefits

Improved DC microgrid architecture
Increased decentralization
Increased accuracy in current sharing
Reduced maintenance cost
Reduced setup complexity

Applications

Military field systems
Disaster response
Emergency redundancy systems

Improved DC Microgrid Architecture