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Ferranti Effect No-Load Transmission Voltage Rise Calculator

The Ferranti effect causes open-circuit receiving-end voltage on long AC transmission lines to rise significantly above the sending-end voltage.

Calculated Result
420.58 kV

Receiving-End Voltage (Vr)

Voltage Rise Percentage

+5.15%

Electrical Length (β·L)

18.00°

Remediation

Shunt reactors required

Calculation Breakdown

  1. Compute propagation phase angle β·L = (ω / c) · Lβ·L = (2π * 50 / 300,000) * 300 = 0.3142 rad (18.00°)
  2. Determine open-circuit receiving end voltage Vr = Vs / cos(β·L)Vr = 400 / cos(0.3142) = 420.58 kV

Receiving Voltage vs Line Length (400 kV Sending)

Interactive visualization based on your current inputs

kV
0.0110219329438100 km200 km300 km400 kmLength (km)Receiving Vr (kV)

What Is the Ferranti Effect No-Load Transmission Voltage Rise Calculator?

The Ferranti effect causes open-circuit receiving-end voltage on long AC transmission lines to rise significantly above the sending-end voltage.

How Does the Ferranti Effect No-Load Transmission Voltage Rise Calculator Work?

The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.

Ferranti Effect No-Load Transmission Voltage Rise Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

V_r = \frac{V_s}{\cos(\beta L)} \approx V_s \left[ 1 + \frac{1}{2} (\beta L)^2 \right], \quad \beta = \frac{\omega}{c} = \frac{2\pi f}{300\,000}

Shunt charging capacitance draws leading capacitive current through line series inductance, inducing an in-phase voltage rise along the line length.

How to Use the Ferranti Effect No-Load Transmission Voltage Rise Calculator

  1. Enter your primary measurements in the input fields above.
  2. Select your preferred units (e.g. metric or imperial) if applicable.
  3. Review or adjust operational assumptions such as field efficiency.
  4. Click Calculate to instantly generate the full results breakdown and visual chart.
  5. Use the Reset button at any time to clear the form and test a new scenario.

Step-by-Step Example Calculation

300 km 400 kV Overhead Line at 50 Hz

Input Values:

sendingVoltageKv:400
lineLengthKm:300
frequencyHz:50

Understanding Your Result

Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.

Factors That Affect the Result

Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.

When Should You Use This Calculator?

Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.

Assumptions & Limitations

  • Assumes distributed-parameter lossless transmission line.

Frequently Asked Questions

Calculation Accuracy & Reference Note

This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.

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