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Exactness of OPF Relaxation on Three-phase Radial Networks with Delta Connections

Journal Article · · IEEE Transactions on Smart Grid
 [1];  [2];  [1];  [3]
  1. California Institute of Technology (CalTech), Pasadena, CA (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  3. Univ. of Virginia, Charlottesville, VA (United States)
Simulations have shown that while semi-definite relaxations of AC optimal power flow (AC-OPF) on three-phase radial networks with only wye connections tend to be exact, the presence of delta connections seem to render them inexact. This paper shows that such inexactness originates from the non-uniqueness of relaxation solutions and numerical errors amplified by the non-uniqueness. This finding motivates two algorithms to recover the exact solution of AC-OPF in unbalanced distribution networks featuring both wye and delta connections. In simulations using IEEE 13, 37 and 123-bus systems, the proposed algorithms provide exact optimal solutions up to numerical precision.
Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE National Renewable Energy Laboratory (NREL), Laboratory Directed Research and Development (LDRD) Program
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1774835
Report Number(s):
NREL/JA-5D00-79429; MainId:33655; UUID:65ee2f45-5c7d-4fec-8b7f-f84dffb80697; MainAdminID:21115
Journal Information:
IEEE Transactions on Smart Grid, Journal Name: IEEE Transactions on Smart Grid Journal Issue: 4 Vol. 12; ISSN 1949-3053
Publisher:
IEEECopyright Statement
Country of Publication:
United States
Language:
English

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