Path Rating Catalog 2013 - Western Electricity Coordinating Council

Revised January 2013
System
Conditions:
Study Criteria:
Remedial
Actions
Required:
Formal
Operating
Procedure:
Allocation:
Interaction
w/Other
Transfer Paths:
North to South: The two Custer-Ingledow tielines can transmit 2850 MW
from Canada to the Northwest when BC Hydro’s load (Canada) is between
approximately 40% and 70% of its annual peak load.
South to North: Restrictions occur during winter peak demand periods due to
thermal and voltage stability concerns in the Northwest and British Columbia.
However, predominant transfers occur during spring months when voltage
stability limitations are not a concern in northwest Washington. Restrictions
also occur when Puget Sound area generation level is low in both heavy
summer and winter load conditions.
1. “BCH System Operating Limits Methodology”, SPA Report No.
SPA2008-02, 15 December 2009.
2. WECC Regional Criteria TPL-(001 thru 004) – WECC-1-CR ─ System
Performance Criteria
North to South: The 230 kV tie lines are directly transfer tripped after loss of
both 500 kV Ingledow-Custer ties when the North to South total transfer
exceeds 400 MW, thus separating the Northwest from Canada. The maximum
amount of generator tripping in Canada (B.C. Hydro) is about 110% of the
scheduled export from Canada to the Northwest. Reactive power equipment
switching scheme is used in BC Hydro (Canada) to control over voltages for
loss of both 500 kV Ingledow – Custer ties when the transfer on the
Ingledow-Custer tie lines is between 2000 and 2850 MW. Certain Northwest
Washington area contingencies require generation tripping in Canada when
flows are above 800 MW. This generation trip is never more than 1850 MW.
Puget Sound Energy generation tripping is also armed at Whitehorn and
Fredonia for some of these contingencies.
South to North: The 230 kV tielines are directly tripped after outages of both
500 kV Ingledow-Custer ties when the South to North total transfer exceeds
400 MW, thus separating the Northwest from Canada. In addition, the BCH –
AB tie lines will be tripped open after loss of both 500 kV Ingledow-Custer
ties when BCH net importing is high
B.C. Hydro’s System Operating Order #7T-18 “Custer-Ingledow 500 kV
Interconnection,” and #7T-64 “BC HYDRO TRANSFER LIMITs”
BPA Dispatcher Standing Order #320 “Operation of the Northern Intertie”
and Standing Order #323 “Bellingham Area-Intalco Load Tripping.”
North to South: All of the capacity is allocated to B. C. Hydro, BPA, and
PSE.
South to North: All of the capacity is allocated to B.C. Hydro, BPA, and
PSE.
North to South: For the Ingledow-Custer intertie 2850 MW accepted rating,
there is a potential interaction with the Raver-Paul loading.
South to North: For the Ingledow-Custer intertie 2750 MW accepted rating
there is a potential interaction with PDCI N-S and COI N-S transfers at higher
levels.
PART VI Item 1-10