Constant(Two-Wire Mid-Point Earthed) Calculator

Constant Overhead DC Formula:

\[ K = \frac{4 \times P^2 \times \rho \times L^2}{P_{loss} \times V_m^2} \]

Power Transmitted (P):

Watt

Resistivity (ρ):

Ω·m

Length of Wire DC (L):

Meter

Line Losses (P_loss):

Watt

Maximum Voltage Overhead DC (V_m):

Volt

Constant Overhead DC (K):

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1. What is Constant Overhead DC?

Constant Overhead DC is defined as the constant of line of an Overhead supply system in a two-wire mid-point earthed configuration. It represents the relationship between power transmission parameters and system losses.

2. How Does the Calculator Work?

The calculator uses the Constant Overhead DC formula:

\[ K = \frac{4 \times P^2 \times \rho \times L^2}{P_{loss} \times V_m^2} \]

Where:

\( K \) — Constant Overhead DC
\( P \) — Power Transmitted (Watt)
\( \rho \) — Resistivity (Ω·m)
\( L \) — Length of Wire DC (Meter)
\( P_{loss} \) — Line Losses (Watt)
\( V_m \) — Maximum Voltage Overhead DC (Volt)

Explanation: The formula calculates the system constant based on power transmission characteristics, material properties, and electrical parameters of the overhead DC line.

3. Importance of Constant Calculation

Details: Accurate calculation of the constant is crucial for designing efficient overhead DC transmission systems, optimizing power delivery, and minimizing energy losses in two-wire mid-point earthed configurations.

4. Using the Calculator

Tips: Enter all values in appropriate units (power in watts, resistivity in ohm-meters, length in meters, losses in watts, voltage in volts). All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is a two-wire mid-point earthed system?
A: It's a DC transmission system configuration where two wires are used with the midpoint of the supply earthed, providing balanced operation and safety.

Q2: Why is resistivity important in this calculation?
A: Resistivity determines how strongly the wire material opposes current flow, directly affecting power losses in the transmission system.

Q3: How does wire length affect the constant?
A: Longer wires increase resistance and power losses, which affects the constant value proportionally to the square of the length.

Q4: What are typical values for this constant?
A: The constant varies based on system design, but lower values generally indicate more efficient transmission systems with reduced losses.

Q5: Can this calculator be used for AC systems?
A: No, this specific formula and calculator are designed for DC overhead transmission systems with mid-point earthing configuration.