Estimates voltage drop and percent regulation along a single overhead (or underground) circuit using the standard short-line approximate formula: Vdrop ≈ √3 × I × (R cos φ + X sin φ) × length, from your own conductor's resistance and reactance per km.
Standards followed
Standard short-line approximate voltage-drop formula (widely used for lines where the shunt capacitance/charging current is negligible)
What it can do
- Voltage drop, percent regulation, and receiving-end voltage from current, power factor, conductor R/X per km, and line length.
Example problem
11kV feeder, 100A at 0.85 lagging PF, R=0.4Ω/km, X=0.35Ω/km, 5km.
- R_total = 0.4×5 = 2Ω, X_total = 0.35×5 = 1.75Ω.
- sin φ = √(1−0.85²) = 0.527.
- Vdrop = √3 × 100 × (2×0.85 + 1.75×0.527) = 173.2 × 2.622 ≈ 454.1V.
- %Reg = 454.1/11000 × 100 ≈ 4.13%.
≈454V drop, ≈4.13% regulation.
Want the full step-by-step version?
Deliberately does NOT embed an ACSR/AAAC/AAC conductor lookup table (to avoid transcription risk) — enter R and X per km for your specific conductor and spacing from its datasheet or a verified conductor-data reference. This short-line approximation omits shunt capacitance; for very long or high-voltage lines, a full line model may be needed.