Student Energy Research Spotlight: Evaluation of Unscheduled Intentional Islanding Methods for Single Phase Grid-Connected Inverters in Compliance with IEEE Standard 1547-2018

By LT Timothy Tencate, USN

A power electronics-based Energy Management System (EMS) is a key component of a microgrid; it manages loads, controls power flow to improve overall efficiency, and disconnects Distributed Energy Resources (DER) from the main grid in the event of a grid fault.

The latter is the focus of the research conducted for this project. Institute of Electronic Engineers (IEEE) Standard 1547 provides the requirements relevant to the connection of a microgrid to the main grid. The standard requires that the disconnection control method maintains connection for a specified time, known as voltage ride-through time, during voltage disturbances in the main grid voltage.

The research conducted for this project explored five different methods of EMS control and their respective algorithms for disconnection from the grid. The response times of disconnection from the grid were simulated using a physics-based model validated by experimental measurements on a laboratory prototype. The simulations were compared against the IEEE Standard 1547 voltage ride-through times to determine if the different controllers’ dynamic responses could meet the requirements. Of the five methods tested, all were in compliance with IEEE Standard 1547 grid disconnection times, but only the two best performing methods, extended MSOGI (Multiple Second Order Generalized Integrator) and true RMS, were able to comply with the voltage ride-through requirements.

About the author 

LT Timothy Tencate, USN, is a student of Electrical Engineering at the Naval Postgraduate School. Contact Dr. Giovanna Oriti at goriti@nps.edu for more information about this research.