Resistivity Using Area Of X-Section(3-Phase 4-Wire OS) Calculator

Formula Used:

\[ \rho = \frac{3 \times A \times V_m^2 \times P_{loss} \times (\cos(\Phi))^2}{2 \times L \times P^2} \]

Area of Overhead AC Wire (A):

m²

Maximum Voltage Overhead AC (V_m):

Line Losses (P_loss):

Phase Difference (Φ):

rad

Length of Overhead AC Wire (L):

Power Transmitted (P):

Resistivity (ρ):

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1. What is the Resistivity Formula?

The resistivity formula calculates the electrical resistivity of a material based on the physical characteristics of an overhead AC transmission line. It provides a measure of how strongly a material opposes the flow of electric current.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \rho = \frac{3 \times A \times V_m^2 \times P_{loss} \times (\cos(\Phi))^2}{2 \times L \times P^2} \]

Where:

\( \rho \) — Resistivity (Ω·m)
\( A \) — Area of overhead AC wire (m²)
\( V_m \) — Maximum voltage overhead AC (V)
\( P_{loss} \) — Line losses (W)
\( \Phi \) — Phase difference (rad)
\( L \) — Length of overhead AC wire (m)
\( P \) — Power transmitted (W)

Explanation: The formula accounts for the relationship between power transmission characteristics and the material's resistivity in a 3-phase 4-wire overhead system.

3. Importance of Resistivity Calculation

Details: Accurate resistivity calculation is crucial for designing efficient power transmission systems, selecting appropriate conductor materials, and minimizing energy losses in electrical networks.

4. Using the Calculator

Tips: Enter all values in appropriate units (area in m², voltage in V, losses in W, phase in radians, length in m, power in W). All values must be positive and valid.

5. Frequently Asked Questions (FAQ)

Q1: What is resistivity and why is it important?
A: Resistivity is a fundamental property of materials that determines how well they conduct electricity. It's crucial for selecting appropriate materials for electrical applications.

Q2: How does phase difference affect resistivity calculation?
A: Phase difference affects the power factor in AC systems, which influences the actual power delivered and thus the calculated resistivity.

Q3: What are typical resistivity values for common conductors?
A: Copper has resistivity of about 1.68×10⁻⁸ Ω·m, aluminum about 2.82×10⁻⁸ Ω·m at 20°C.

Q4: Does temperature affect resistivity?
A: Yes, resistivity generally increases with temperature for conductors. This formula assumes constant temperature conditions.

Q5: When is this specific formula applicable?
A: This formula is specifically designed for 3-phase 4-wire overhead AC transmission systems with balanced loads.