20180208PAC to Staff Pintura RAS - Assessment.docx

PacifiCorp Main Grid Planning
PRC-(012 through 014)-WECC-CRT2
Attachment B RAS Assessment
RAS Name
Three Peaks Solar RAS
Reporting Party
PacifiCorp
Group Conducting Assessment
PacifiCorp Main Grid Planning
Assessment Date
10-27-2016
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 N-1 loss of the Three Peaks 345/138 kV transformer or the Sigurd – Parowan – West Cedar 230 kV line or Sigurd – Tushar 138 kV line, can potentially overload various elements in the southwest Utah region, namely Pintura – West Cedar 138 kV line, West Cedar 230/138 kV transformer and Sigurd – Parowan 230 kV line etc.
To resolve this overload, generation tripping is required.
Loss of Three Peaks 345/138 kV transformer will trip Three Peaks Solar (Steven’s Ville Collector) and Granite Mountain West solar projects.
Loss of the Sigurd – Parowan – West Cedar 230 kV line will trip Granite Mountain West solar project
Loss of the Sigurd – Tushar 138 kV line will trip Granite Mountain West solar project.
Failure to operate, approximately 200 MW (<300 MW) of peak load can be impacted and up to 450 MW (<1000MW) of generation will be impacted. Thus, this scheme will be classified as LAPS.
Study results indicate that the Three Peaks Solar LAPS is required to meet post contingency reliability requirements (thermal overloads).
This RAS assessment included the following:
Study Years
2016
System Conditions
Heavy and light load conditions in Southwest Utah region.
Contingencies analyzed
(select what applies)
N-1
N-1-1
N-2
Extreme
N-1
Date when the technical studies were completed
October 2016
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
This RAS is still in process of completion and is planned to be in-service by end of 2016.
Substation Concerned Are: Three Peaks and Pintura.