20180208PAC to Staff Bridger RAS - Assessment.docx

PacifiCorp Main Grid Planning
PRC-(012 through 014)-WECC-CRT2
Attachment B RAS Assessment
RAS Name
Jim Bridger RAS
Reporting Party
PacifiCorp
Group Conducting Assessment
PacifiCorp Main Grid Planning
Assessment Date
12/31/14
Review the scheme purpose and impact to ensure proper classification, is it (still) necessary, does it serve the intended purposes, and does it continue to meet current performance requirements.
The Jim Bridger RAS is designed to maintain system stability and to eliminate line overloads for loss of any of the 345 kV lines west of Jim Bridger substation, west of Populus,or north of Three Mile Knoll substation.The RAS control system will take action for any event that will cause system instability or performance violations by tripping generation at Jim Bridger Plant.
The Bridger RAS scheme is listed as a WAPS. This designation is appropriate due to the level of generation tripping (>1000 MW) and potential impacts to the Idaho Power and BPA systems for failure of the scheme to operate.
The Bridger RAS is necessary; numerous contingencies resulted in thermal overloads without generation tripping. The RAS scheme was successful in mitigating performance violations for all contingencies analyzed. The scheme was therefore determined to meet performance criteria.
This RAS assessment included the following:
Study Years
2014
System Conditions
Heavy summer conditions with simultaneous Bridger West and Path C stress.
Contingencies analyzed
(select what applies)
N-1
N-1-1
N-2
Extreme
N-1, N-2, N-1-1
Date when the technical studies were completed
2014
Does the RAS comply with NERC standards and WECC Criteria?
Yes
Discuss any coordination problems found between this RAS and other protection and control systems during this (most recent) assessment.
None.
Provide a Corrective Action Plan if this RAS was found to be non-compliant or had coordination problems during this (most recent) assessment (should be NA for owner’s initial assessment).
N/A
Additional Notes
Refer to 2014 Summer Bridger West SOL Study for further information.