3-Phase Balanced Power Line Series Impedance and Shunt Admittance Calculator (Symmetrical Components)

For three-phase, balanced transmission lines.  Reports positive, negative, and zero sequence symmetrical components of line impedance.  Lines are positioned as shown below with x and y coordinates and resistivity is selected based on type of earth below the line.  Method is based on Power System Analysis and Design [1] pages 197 on.  Earth is replaced with earth return conductors as shown in the Glover textbook referencing Carson [2]

https://github.com/rsparks3/power-line-impedance-calculator/tree/main

[1] J. D. Glover, T. J. Overbye, and M. S. Sarma, Power System Analysis & Design. Boston, MA: Cengage Learning, 2017.

[2] John R. Carson, “Wave Propagation in Overhead Wires with Ground Return,” Bell System Tech. J. 5 (1926): 539–554.

System frequency:
Right of way material: Sea water Swampy ground Average damp earth Dry earth Pure slate Sandstone Custom resistivity
Ground resistivity: (ohm meter)
A Position (x, y): , (ft)
B Position (x, y): , (ft)
C Position (x, y): , (ft)
Phase conductor resistance: (ohms per mile per conductor)
Phase conductor geometric mean radius (GMR): (feet)
Phase conductor outer diameter (OD): (inches)
Phase bundle size: (cables per bundle)
Bundle spacing (if bundle size >1): (ft)

Neutral 1 position (x, y): , (ft)
Neutral 2 position (x, y): , (ft)
Neutral conductor resistance: (ohms per km per conductor)
Neutral conductor geometric mean radius (GMR): (feet)
Neutral conductor outer diameter (OD): (inches)



Series impedance:
Z₀ =
Z₁ =
Z₂ =


Shunt admittance:
Y₀ =
Y₁ =
Y₂ =