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Krishna K.C.

Jan 2023 · Academic project

132 kV Double-Circuit Transmission Line

~200 km · Conductor Selection · Sag-Tension · Insulation Coordination

Design of a 132 kV double-circuit overhead transmission line spanning approximately 200 km, covering conductor selection, sag-tension, insulation coordination and tower planning with technical and cost analysis.

  1. 1Conductor selection
  2. 2Sag-tension
  3. 3Insulation coordination
  4. 4Tower planning
Schematic of a 132 kV double-circuit overhead transmission line spanning approximately 200 kilometers. Three lattice towers each carry six conductors — three per side — strung in sagging catenary spans with insulator strings. Numbered markers highlight the key design decisions: conductor selection, sag-tension calculations, insulation coordination and tower planning.

Illustrative diagram — not a client or employer drawing.

01Project overview

This project designed a 132 kV double-circuit overhead transmission line spanning approximately 200 km.

The scope included conductor selection, sag-tension calculations, insulation coordination and tower planning, together with technical and cost analysis.

02Engineering problem

A long overhead line has to carry power reliably across ~200 km while staying mechanically sound and electrically safe under varying loading and weather.

That means choosing conductors, spans, clearances and towers that balance performance, safety and capital cost.

03Responsibilities

  • Designed a 132 kV double-circuit line spanning approximately 200 km.
  • Performed conductor selection and sag-tension calculations.
  • Addressed insulation coordination and tower planning.
  • Prepared technical and cost analyses balancing structural safety, electrical performance and capital cost.

04System architecture

  • A double-circuit tower carries two three-phase circuits, doubling capacity on a shared corridor.
  • Conductors are strung between towers with spans and sags set by sag-tension analysis.
  • Insulation and clearances are coordinated to withstand the line's operating and transient voltages.

05Engineering methodology

  • Conductors were selected for the required capacity and mechanical loading.
  • Sag-tension calculations set span geometry and ground clearance across conditions.
  • Insulation coordination and tower planning addressed electrical withstand and structural support.

06Tools & platforms

  • AutoCAD
  • MATLAB
  • Transmission-line design methods

07Validation approach

  • The design was supported by technical analysis of structural safety and electrical performance.
  • A cost analysis was prepared alongside the technical work to weigh capital cost against performance.

08Engineering considerations

  • The work balanced structural safety, electrical performance and capital cost.
  • Double-circuit construction increases corridor capacity for a given right-of-way.

09Outcomes

  • A 132 kV double-circuit line design over approximately 200 km with conductor, sag-tension, insulation and tower decisions.
  • Technical and cost analyses documenting the engineering trade-offs.

10Skills demonstrated

  • Transmission-line design
  • Conductor selection
  • Sag-tension analysis
  • Insulation coordination
  • Tower planning
  • Technical & cost analysis

Confidentiality note

The illustration below is a schematic portfolio representation of a double-circuit line and its key design decisions, not a construction drawing.