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This content will become publicly available on April 23, 2019

Title: Survivability of Autonomous Microgrid during Overload Events

Grid-forming sources are voltage sources that draw necessary currents to meet any load changes. A load step can cause part or all of these sources to become overloaded in a microgrid. This paper presents an overload mitigation controller that addresses the two overload issues in a microgrid by actively controlling the sources’ frequency. When part of the sources in a microgrid is overloaded, the controller autonomously transfers the extra load to other sources by rapidly reducing its frequency. The frequency difference between sources during transient results in a change of phase angle, which redistributes the power flow. When all sources in a microgrid are overloaded, each source keeps dropping the frequency. Therefore, under frequency load shedding can be used to trip the non-critical loads resulting in the survival of microgrid. The advantages of these concepts are that communications between sources are not needed during transient, and the robust voltage control is maintained. Lastly, simulation and field tests from CERTS/AEP microgrid test site verify that the control strategy is effective in both purely inverter-based microgrids and inverter & generator mixed microgrids.
 [1] ;  [2] ;  [3]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Univ. of Wisconsin, Madison, WI (United States). Dept. of Electrical and Computer Engineering
  3. American Electric Power, Groveport, OH (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1949-3053
Grant/Contract Number:
Accepted Manuscript
Journal Name:
IEEE Transactions on Smart Grid
Additional Journal Information:
Journal Name: IEEE Transactions on Smart Grid; Journal ID: ISSN 1949-3053
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE Office of Electricity Delivery and Energy Reliability (OE)
Country of Publication:
United States
24 POWER TRANSMISSION AND DISTRIBUTION; Microgrids; Frequency control; Voltage control; Inverters; Transient analysis; Switches; survivability; overload mitigation; grid-forming source; droop control
OSTI Identifier: