20180208PAC to Staff Naughton RAS - Assessment.docx

PacifiCorp Main Grid Planning
PRC-(012 through 014)-WECC-CRT2
Attachment B RAS Assessment
RAS Name
Naughton RAS
Reporting Party
PacifiCorp
Group Conducting Assessment
PacifiCorp Transmission Planning
Assessment Date
11/15/2017
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.
Naughton RAS is designed to prevent overloads on230 kV and 138 kV transmission system following credible N-2 loss of the Naughton – Ben Lomond 230kV and Birch Creek – Ben Lomond 230kV lines in conjunction with heavy stressed on new Evanston West path (≥ 800 MW): Naughton – Treasureton 230kV, Naughton – Ben Lomond 230kV, Birch Creek – Ben Lomond 230kV & Railroad – Croydon 138kV lines.
The Naughton RASis listed as a Local Area Protection Scheme. This designation is appropriate due to the level of generation tripping (< 1000MW). There is no load loss exposure for failure to operate or for inadvertent operation of the scheme. Impacts of failure of the scheme to operate are limited to thermal overloads on the local 230kV and 138kV transmission systems.
Study results indicate that the Naughton RASis still necessary to mitigatepost-contingency thermal overloads on the local 230kV and 138kV transmission systems. The scheme is effective, and no performance violations are seen following scheme action.
Study Years
2017 - 2019
System Conditions
Heavy and lightload levels in conjunction with stressed flow on the PacifiCorp internal new Evanston West Path.
Contingencies analyzed
(select what applies)
N-1
N-1-1
N-2
Extreme
N-2
Date when the technical studies were completed
2017
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
N/A