Engineering topics

Smith Jr, John

Publications and source records attributed to Smith Jr, John.

3 records

DOE OSTI2024

A Networked Microgrid Framework and Testbed for Communication, Controls, and Optimization Testing

This paper presents the development and experimental results of a networked AC microgrid testbed located at Oak Ridge National Laboratory. The testbed comprises two, 480V three-phase, four wire microgrids designed to operate standalone, grid-tied, or as a network of microgrids. This testbed represents both the state of the industry, by incorporating grid-assets commonly found in real microgrids, and the state of the art, as it is a platform to evaluate advanced controllers. The main elements of this networked microgrid testbed are presented in this paper including a Scenario Manager, local microgrid controls, and a networked microgrid control. The Scenario Manager has the objective of emulating real-world conditions. The local microgrid controller oversees standalone, grid-tied, or islanded operation. The microgrid control is a higher-level control that coordinates interaction between islanded microgrids. This paper delves into these controllers and validates their operation in the networked microgrid testbed showcasing the operational flexibility and advance control capabilities.

Ferrari Maglia, Max↗

DOE OSTI2024

Microgrid to Microgrid Synchronization with Grid-Forming Inverters: Challenges and Solution

Research on network microgrids has primarily focused on control and optimization. However, application aspects such as microgrid-to-microgrid synchronization have not been fully addressed in existing literature. This paper first addresses the challenges of networking microgrids with grid-forming inverter in droop control. Then, it proposes a pre-synchronization algorithm to improves the synchronization speed and transient stability. To improve the speed, the phase difference between adjacent microgrids is minimized. Transients such as inrush current and oscillations are effectively mitigated by increasing the virtual impedance during interconnection. The proposed strategy allows smooth transitions when reconfiguration of the microgrids is needed. The applicability of this strategy to today’s microgrid systems is demonstrated through a validation in a 480V three-phase network microgrid testbed with commercial-grade inverters, protective devices, and switchgear.

Ferrari Maglia, Max↗

DOE OSTI2022

Microgrid Communications Using the Open-Source Open Field Message Bus (OpenFMB) Framework Applied to a 480V, 100kW Laboratory Microgrid

Microgrids require an extensive communication infrastructure to allow interoperability between the microgrid controller and assets. However, the lack of standardization of data structures combined with the variety of communication protocols poses several challenges to the implementation of a communication network. This paper presents an application of the open-source Open Field Message Bus (OpenFMB) framework to simplify the communication layer in microgrids. This work leverages the OpenFMB protocol translation and data model extensions to reduce the complexity in the microgrid communications. Conducted in a laboratory microgrid, the case study demonstrates how the OpenFMB provides predefined data models and simplifies the communication layer by providing information exchange between multiple legacy communication protocols.

Ferrari Maglia, Max↗