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Recovery from Large-Scale System Events Using Oasis Microgrids

By John Kumm, P.E., POWER Engineers

Abstract:

Traditional reliability analysis predicts power system performance under contingencies that remove a few selected lines, generators, or substation buses. These analyses identify grid improvements that result in high-availability system performance for the vast majority of what could be considered high-probability, low impact scenarios. Recent hard experience has demonstrated that some lower-probability scenarios can remove large elements of the power system from service for days or weeks.

Small-footprint microgrids are proving capable of supplying critical power to point and campus loads during loss of the local distribution system. Microgrids have the further attraction of facilitating the addition of new distributed renewables and energy storage. Despite these strengths and improving economics, local regulations and their own newness are holding back broad adoption of smaller microgrids for the moment.

Today, work is taking place to increase the robustness of local or regional electric power systems through a concept we call the oasis microgrid. Using a set of pre-planning activities, the utility identifies a subset of transmission, generation, and load resources that can be started and operated indefinitely even if large segments of their regional bulk electric system are unavailable. This paper describes a natural disaster scenario that would leave the U. S. Pacific Northwest with a ruined bulk electric system and the studies being undertaken to prepare to operate a generation, transmission, and distribution subsystem for local critical power and to aid in recovery.

This paper was presented at the 2016 CIGRE Grid of the Future Symposium.

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