Transmission Line Software

Transmission Line

Electrical Line Design and Analysis for Transmission & Distribution calculates detailed electrical conductor parameters, the line sag and line tension, operating temperature characteristics, conductor ampacity characteristics, and ampacity derating characteristics of overhead transmission and distribution lines. This module includes a comprehensive characteristic model of the mutual coupling effect between multiple line circuits to enable accurate modeling of the electrical transmission and distribution system. The pattern and layout of circuits & ground wires for transmission tower and overhead lines are illustrated using the user-friendly graphical interface displays. ETAP makes it easy to design new transmission and distribution circuits, size transmission and distribution lines, and verify the parameters of existing overhead lines.

Line Constants

  • Libraries for conductor & ground wires
  • Prebuilt common line configurations
  • Generic X,Y, Z coordinate configuration
  • Mutual line coupling
  • Impedance matrix for phase & sequence
  • Line can be transposed or un-transposed
  • Utilize short or long-line characteristic models
  • Soil model contains multiple layers for grounding
  • Impedances either calculated or user-defined

Line Ampacity Analysis

  • Calculate Conductor ampacity vs. temperature
  • Conform with IEEE 738-1993 Standard
  • Verify, for various loading conditions, maximum operating temperature
  • Determine derated ampacity based on specified temperature limit
  • Factors include solar heat, weather, & geographic location

Sag & Tension Calculations

  • Sag & tension versus temperature
  • Incorporate multiple spans between end-to-end structures
  • Utilize level spans of unequal lengths
  • Resolve spans of unequal length with different horizontal planes
  • Calculation includes the effects of temperature, wind, & k factor


  • Graphical user-friendly interface
  • Multiple options for entry of impedance or physical parameters
  • Multi-circuit including single, two & three-phase
  • Multiple ground wires, segmented and/or unsegmented
  • Line layout types are selectable
  • General line layout is user-definable
  • Model mutual coupling effect of line branches
  • Include ground resistance of towers


  • Calculate impedance automatically based on physical parameters
  • Calculations for Sag, tension, Ampacity, & temperature
  • Analysis of Sag & tension versus temperature
  • Analysis incorporates towers of same or different heights
  • Analysis of conductor ampacity versus temperature
  • Able to display parameters in phase/sequence domain
  • Create new designs or size lines with a fully integrated tool
  • Calculator for converting physical parameters to impedance


  • Phase domain series branch impedance matrices
  • Sequence domain series branch impedance matrices
  • Phase domain shunt branch susceptance matrices
  • Sequence domain shunt branch susceptance matrices
  • Relationship of Sag & tension versus temperature
  • Relationship of Conductor ampacity versus temperature

To learn more about ETAP Transmission & Distribution Line Analysis Software, please EMAIL US.