A team of Brattle experts has been engaged by National Grid Electricity Transmission to study the potential of topology optimization to aid in increasing transfer capability and reducing constraint management costs in the Great Britain Transmission System. According to National Grid, the reconfigurations found by Brattle’s topology optimization analysis increased the limits of transmission constraints by 3% to 12.3%, which could lead to cost savings of £14-40 million annually. The transfer capability increase is achieved with the existing transmission equipment.
The topology optimization algorithms were originally developed by a team including members of The Brattle Group, with funding and support from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E).
The analysis estimated the economic impacts of the increase in transfer capability that topology optimization provides. The study considered both line switching, substation reconfigurations, and the settings of phase-shifting transformers as decision variables in the optimization effort. The identified solutions achieved between 3% and 12.3% increases in transfer capacity on thermally-limited constraints in the British transmission system for scenarios selected and provided by National Grid.
“Integrating topology optimization with the existing National Grid decision support tool set would better enable engineers and operators to minimize transmission congestion costs for the end consumers,” noted Brattle Senior Associate Pablo Ruiz, a co-author of the study. “The results are in line with our findings in U.S. markets, such as ERCOT and PJM.”
With transmission constraints costing the end consumers in Great Britain around £340 million annually, the study found that the savings can be quite substantial (up to £40 million a year). In addition, the inclusion of substation reconfiguration and phase-shifting transformer settings in the optimization, together with line switching, can more than double the transfer capability gains obtained by line switching optimization alone.
The study was prepared by Dr. Ruiz and Principals Judy Chang and Johannes Pfeifenberger. Additional information on the study, provided by National Grid, can be found in the National Grid Innovation Report (page 14) and the Transmission Network Topology Optimisation Project Report. Additional information on topology optimization can be accessed below.