Path Rating Catalog 2013 - Western Electricity Coordinating Council

III–12. SunZia Southwest
Transmission Project
Revised December 2011
Accepted Rating
Existing Rating
Other
Location:
Definition:
Transfer Limit:
Critical
Disturbance
that limits the
transfer
capability:
When:
Two new 500kV transmission lines between central New Mexico and central
Arizona.
Included lines: First two 500 kV lines from SunZia E to SunZia S (70% series
compensated), second two 500 kV lines from SunZia S to Willow (50%
series compensated) and last two 500 kV lines from Willow to Pinal_C (50%
series compensated).
Metered End: SunZia E end of the transmission system
East to West: 3,000 MW (non-simultaneous).
West to East: Not rated.
East to West:
Loss of one of the two SunZia E to SunZia S 500 kV lines loads the
remaining SunZia E to SunZia S 500 kV line to its emergency rating.
By letter dated March 25, 2011, SunZia Southwest Transmission Path Rating
was granted Phase III status by the PCC Chair.
System
Conditions:
Study Criteria:
Remedial
Actions
Required:
Formal
Operating
Procedure:
Allocation:
Interaction
w/Other
Transfer Paths:
Both WECC 2013 heavy winter and heavy summer cases were used as a base.
East to West case: 3000 MW non-simultaneous transfer in both cases.
NERC/WECC Reliability Criteria for Transmission System Planning
RAS of tripping generation located at SunZia E is required in the event of loss
of both SunZia E – SunZia S 500 kV lines.
A formal operating procedure will be developed prior to project energization.
Exact allocation capacity has yet to be determined.
There are some possible simultaneous interactions with Path 50 and Path 54.
The conceptual simultaneous operating nomogram limits have been
determined.
PART VI Item 1-240