What Is the Corona Discharge & Disruptive Critical Voltage Calculator?
Corona is partial electrical breakdown of air surrounding energized conductors when the local surface gradient exceeds dielectric breakdown strength (~30 kV/cm peak).
How Does the Corona Discharge & Disruptive Critical Voltage Calculator Work?
Calculates dielectric surface gradient as a function of conductor radius and spacing; if operating phase voltage exceeds Vd, ions dissipate energy as Peek loss.
Corona Discharge & Disruptive Critical Voltage Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
V_d = 21.2 m_0 delta r lnleft( rac{D}{r}
ight) quad [ ext{kV/phase}], quad P = rac{242.2}{delta}(f + 25)sqrt{ rac{r}{D}}(V - V_d)^2 imes 10^{-5}
Peek empirical equations for critical disruptive voltage and corona power loss in high-voltage transmission lines.
How to Use the Corona Discharge & Disruptive Critical Voltage Calculator
- Input nominal line-to-line voltage in kV, conductor radius in cm, inter-phase spacing in cm, and relative air density factor.
Step-by-Step Example Calculation
275 kV Overhead Transmission Line
Input Values:
operatingVoltageKv:275
conductorRadiusCm:1.5
spacingCm:450
airDensityDelta:0.98
Worked Steps: Disruptive critical voltage Vd = 259.4 kV (line-to-line), Corona active with 1.84 kW/km power loss.
Understanding Your Result
Displays disruptive critical voltage Vd, visual corona voltage Vv, and total 3-phase corona power loss in kW/km.
Factors That Affect the Result
- Wet weather, rain, and surface stranding irregularities drastically depress critical voltage, multiplying corona losses by 10x to 50x.
When Should You Use This Calculator?
- EHV and UHV transmission line design (bundling sub-conductors), radio interference mitigation, and line loss assessment.
Assumptions & Limitations
- Applies to symmetrical 3-phase overhead configurations under fair-weather conditions.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard classical Peek empirical high-voltage formulation.