Path Rating Catalog 2013 - Western Electricity Coordinating Council

15. Midway - Los Banos
Revised January 2011
Accepted Rating
Existing Rating
Other
Location:
Definition:
Transfer Limit:
Critical
Disturbance
that limits the
transfer
capability:
Between central and southern California within the PG&E system and south
of Los Banos substation (PG&E internal Path 15).
Measured at Los Banos for all 500 kV lines and at Gates for all 230 kV lines
for both north-to-south and south-to-north flows:
Midway-Los Banos 500 kV line (at Los Banos)
Gates-Los Banos # 1 and #3 500 kV lines (at Los Banos)
Gates-Panoche #1 & #2 230 kV lines (at Gates)
Gates-Gregg 230 kV line (at Gates)
Gates-McCall 230 kV line (at Gates)
The transfer limit ranges from 2000-3265 MW from north to south.
The transfer limit ranges from 4800-5400 MW from south to north.
From north to south:
Midway-Gates and Midway-Los Banos 500 kV double line outage.
Double Palo Verde unit outage.
Los Banos-Tesla and Los Banos-Tracy 500 kV double line outage.
From south to north:
Double line 500 kV outages between Tesla and Midway.
When: The 3265 MW north-to-south rating was established in the August 5, 2002
Path 15 Upgrade north-to-south Project Comprehensive Progress Report.
Phase III Status granted on October 23, 2003.
The 5400 MW south-to-north rating was established in the September 18,
2001 Path 15 Upgrade Project Comprehensive Progress Report. A letter
from the PCC chair indicating the Phase II report was accepted and granting
Phase III status was distributed on February 5, 2003.
System
Conditions:
Study Criteria:
Remedial
Actions
Required:
Formal
Operating
Procedure:
Allocation:
Interaction
w/Other
Transfer Paths:
The north-to-south path rating was based on north-to-south transfers under
heavy summer (high temperature) operating conditions.
The south-to-north path rating was based on south-to-north transfers under
light winter operating conditions.
NERC/WECC Planning Standards.
Remedial actions are employed on an as needed basis for double line
outages between Tesla and Midway.
CISO T-122 and PG&E O-51 operating procedures which are periodically
updated.
PG&E, SCE, SDGE, CDWR, and various new owners.
For high north-to-south flows on Path 15 and high north-to-south flows on
COI and/or PDCI it is necessary to operate based on a nomogram.
Path 15 north-to-south transfer limit can be significantly less with high
generation levels in the Midway area because of Path 26 limitations.
For high south-to-north flows on Path 15 and high east-to-west flows on
West of Borah it is necessary to operate based on a nomogram.
PART VI Item 1-40