General Information
All participants of this OASIS node are members of the WSCC, and use the WSCC Path Rating Catalog for determining TTC.
WSCC PATH RATING CATALOG
Disclaimer
This catalog contains descriptions of path components and describes path ratings as provided by the individual WSCC members. The path ratings in this catalog are "Maximum Path Transfer Capabilities" and not "first Contingency Incremental Transfer Capabilities." The ratings reflect capabilities based on technical limits determined from system studies. They do not represent Available Transmission Capacity (ATC) because they do not indicate the degree to which the path transfer capability has been committed with existing transactions. It is not the intent that this document be used for the purposes of validating the applicability of a path or to determine if the WSCC procedures were followed to determine its rating. It is only intended to compile currently available information into a single document.
Introduction
This Path Rating Catalog contains a collection of discussions on individual path ratings within the WSCC system. A path rating can be related to an individual transmission line or a combination of parallel transmission lines. The transfer path may be composed of transmission lines between control areas or internal to a control area, or a combination of both.
This compilation of transfer path rating information provides a single source of information to WSCC members. From this data, transfer limitations can be identified during the regional planning analysis. Ratings that are not approved are submitted for information only.
Identification of path ratings with supporting information assures that any relation between existing ratings and proposed new projects can be identified during a project review process according to the WSCC "Interim Procedures for Regional Planning Project Review and Rating Transmission Facilities."
Path Descriptions
The content of each path description should include:
- An explanation of the facilities that make up the transmission path.
- A discussion of the non-simultaneous path rating, the conditions used to achieve the rating, when and by whom, and any necessary Remedial Action Schemes.
- An identification of interactions or relationships with other paths (nomograms.)
- Ownership and Allocation/rights on the path.
Applicability
Path ratings in the WSCC region are assumed to be valid under all conditions including those used to rate the path, unless specified otherwise.
Document Updates
Additional information supporting existing transfer path ratings is welcome. Any changes, upgrades, or rerates in path ratings and new transfer path ratings must follow the WSCC Interim Procedures for Regional Planning Project Review and Rating Transmission Facilities.
WSCC Procedures
Prior to August 1991, project ratings for new facilities were defined using the "Annual Progress Reporting Procedure." In August 1991, the "Notification Procedure for Changes in Facility Ratings and/or Operating Procedures" was adopted for documenting uprates in existing facilities. This augmented the "Annual Progress Reporting Procedure." In November of 1992, the "Policies and Procedures for Rating Transmission Facilities" was adopted which added a formal review process for checking the proposed non-simultaneous rating and simultaneous operating problems of the new or existing path being rated. In November of 1993, the "Interim Procedures for Regional Planning Project Review and Rating Transmission Facilities" was adopted to address issues related to Regional Transmission Planning. This new procedure incorporated into it the "Policies and Procedures for Rating Transmission Facilities" of November 1992.
Specific Path Information:
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