345kV/161kV/69kV/34.5kV Transmission Line Rating & Facilities Study

345kV/161kV/69kV/34.5kV Transmission Line Rating & Facilities Study, throughout Iowa

Facilities Study for Over 4,000 Miles

Realtime worked with an Iowa utility to assess the safe operating capacity for over 4,000 miles of transmission lines, ranging from 34.5kV-345kV.

It is imperative for utility managers to be aware of the safe operating capacity of the transmission lines they are responsible for. Under the National Electrical Safety Code (NESC), safe operating capacity is governed by the clearance, or distance between the line and the ground, and other features such as buildings, vegetation, and other conductors, at maximum load and steady state conductor temperature. Realtime adheres to these standards and guidelines to provide the most accurate recommendations and solutions for optimizing safe operating capacity for the Client.

Project Scope:
Utilizing LiDAR survey data and PLS-CADD, a sophisticated modeling software tool, Realtime provided transmission line rating analysis and study reports to confirm NESC compliance.  Code compliance can be assured in marginal situations by remedial design or “up-rating” to improve performance.

Line analysis included:

  • Rating Report – NESC code status at predetermined conductor temperatures.
  • Clearance encroachment to ground obstructions or other distribution facilities at specified operating temperature.
  • Summary of failing spans versus increasing temperature.

Design Challenges & Solutions:
Most of the transmission lines included in this project carry secondary lines of lower voltage and/or other conductors (telephone, CATV, etc.). Realtime assisted the Client in identifying the current configuration of transmission line under-build, creating an up-to-date asset database as a valuable by-product of the rating studies.