Path Rating Catalog 2013 - Western Electricity Coordinating Council

55. Brownlee East
Revised January 2013
Accepted Rating
Existing Rating
Other
Location:
Definition:
Transfer Limit:
Southwest Idaho
The transfer path is comprised of the following lines:
Line
Brownlee-Boise Bench #1 230 kV
Brownlee-Boise Bench #2 230 kV
Brownlee-Boise Bench #3 230 kV
Brownlee-Horse Flat #4 230 kV
Brownlee-Ontario 230 kV
Oxbow-Starkey 138 kV
Quartz-Ontario 138 kV
West to East: 1915 MW
Metered End
Brownlee
Brownlee
Brownlee
Brownlee
Brownlee
Oxbow
Quartz
Critical
Disturbance
that limits the
transfer
capability:
When:
System
Conditions:
East to West: Not defined. However, this transfer path does not restrict east
to west transfers through Idaho.
Post transient reactive margin at the Boise Bench 230 kV following the loss
of the Midpoint-Summer Lake 500 kV line, or the loss of two Jim Bridger
345 kV lines with tripping of two Jim Bridger units, or the loss of two
Brownlee-Boise Bench 230 kV lines. Thermal limits on the remaining two
Brownlee-Boise Bench 230 kV lines for loss of the other two lines.
In 1983, the Brownlee East transfer limit was established by Idaho Power
Company and was revised in 1986 when the Northwest to Idaho transfer limit
was restudied. After the July 2 and 3, 1996 disturbances, the Brownlee East
transfer limit was restricted to 1560 MW. After the completion of the
Brownlee-Boise Bench 230kV Project in 2001, the Brownlee East
transmission path attained an Accepted Rating of 1750 MW West to East.
The accepted rating was increased to 1850 MW West to East for the summer
of 2004 when the final phase of the project, which included the 2 nd Brownlee-
Oxbow 230 kV circuit, was completed.
Due to the addition of the Elkhorn Wind Generation Project, the Brownlee
East transmission path rating was modestly increased again in 2008 to 1915
MW with the facility additions of Brownlee C232 75 Mvar 230 kV shunt
capacitor bank and increasing the ampacity rating of Ontario C231 series
capacitor in the Brownlee-Ontario 230 kV line. To support -550 MW
Hemingway-Summer Lake 500 kV line (Path 75) transfer rating simultaneous
with Brownlee East at 1915 MW, the Brownlee C232 230 kV shunt capacitor
bank was increased to 112.5 Mvar.
The Brownlee East transfer limit was studied with simultaneous high imports
of -1200 MW on Idaho-Northwest (Path 14) with -550 MW on the Midpoint-
Summer Lake 500 kV line (Path 75), and with high T E Roach Complex
generation at peak summer load conditions. The total West-to-East flow on
Brownlee East and Hemingway –Summer Lake 500 kV was studied with
flows ranging from 2425 to 2465 MW.
PART VI Item 1-153