Transformer Differential Protection Studies for Dominion Energy's Blackstart Operations
Sergio A. Dorado-Rojas, Xiawen Li, Ren Liu, and Micah J. Till
bib
@inproceedings{dorado-rojas2021b,
title = {Transformer {{Differential Protection Studies}} for {{Dominion Energy}}'s {{Blackstart Operations}}},
booktitle = {{{CIGRE US National Committee Grid}} of the {{Future Symposium}}},
author = {{Dorado-Rojas}, Sergio A. and Li, Xiawen and Liu, Ren and Till, Micah J.},
year = 2021,
month = oct
}Abstract
Blackout events are likely to happen in modern power systems due to abnormal weather events and weaknesses in the digital infrastructure of the grid. Utility companies design System Restoration Plans (SRPs) to provide the most secure and fastest way to bring customer service back by specifying detailed blackstart maneuvers. However, the system in a restoration condition lacks the electrical strength of the network during normal conditions. In particular, protective relaying is critical to the success of a blackstart. Misoperation of protection schemes could potentially delay the system-wide restoration efforts and further damage the affected equipment. This work addresses system protection performance during blackstart using an evaluation methodology based on real-time simulation in RTDS. The study case is a differential protection scheme for a 500 kV transformer within a cranking path outlined in Dominion's SRP. We showed that the protection scheme behaves correctly for internal faults, but our experiments were not conclusive regarding external faults. We analyzed this case further and proposed solutions to reach more demonstrative results so that the performance of relaying functions can be correctly assessed during blackstart.