Formula Used:
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The formula calculates the resistivity of conductor material using volume, line losses, maximum voltage, transmitted power, and wire length for a DC 3-wire system. Resistivity measures how strongly a material opposes electric current flow.
The calculator uses the formula:
Where:
Explanation: The formula calculates material resistivity by considering the relationship between conductor volume, power losses, voltage, transmitted power, and wire length in a DC 3-wire system.
Details: Accurate resistivity calculation is crucial for selecting appropriate conductor materials, designing efficient power transmission systems, and minimizing energy losses in DC 3-wire overhead lines.
Tips: Enter all values in appropriate units (volume in m³, losses in W, voltage in V, power in W, length in m). All values must be positive numbers greater than zero for accurate calculation.
Q1: Why is resistivity important in power transmission?
A: Resistivity determines how much energy will be lost as heat during transmission. Lower resistivity materials result in more efficient power delivery.
Q2: 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, and silver about 1.59×10⁻⁸ Ω·m at 20°C.
Q3: How does temperature affect resistivity?
A: Resistivity generally increases with temperature for most conductors due to increased atomic vibrations that impede electron flow.
Q4: What factors influence line losses in DC transmission?
A: Line losses are influenced by conductor material resistivity, cross-sectional area, length, and the square of the current flowing through the conductor.
Q5: Why use a 3-wire DC system instead of 2-wire?
A: 3-wire DC systems provide both positive and negative voltages relative to a neutral wire, allowing for more flexible voltage selection and reduced conductor material for the same power transmission.