Answer: 80.12 ohms

Explanation: Shunt Generator Resistance Calculation

Carlo Abad

The shunt field winding of a shunt generator has a resistance of 80 ohms at 20°C. After several hours of continuous operation, the winding temperature rises to 50°C. How much is the winding resistance under this condition? Assume the resistance temperature coefficient of copper to be 0.004 ohm per degree at 0°C.​

The resistance temperature coefficient of copper is used to determine how the resistance of a material changes as its temperature changes. At 0°C, the resistance temperature coefficient of copper is 0.004 ohm per degree.

To calculate the winding resistance of the shunt generator at 50°C, we can use the formula:

R50 = R20 + (RTCopper * (T50 - T20))

where:

R50 is the resistance of the winding at 50°C

R20 is the resistance of the winding at 20°C

RTCopper is the resistance temperature coefficient of copper (0.004 ohm per degree)

T50 is the temperature of the winding at 50°C

T20 is the temperature of the winding at 20°C

Given that R20 = 80 ohms, T20 = 20°C and T50 = 50°C, we can substitute these values into the formula:

R50 = 80 + (0.004 * (50 - 20))

R50 = 80 + (0.004 * 30)

R50 = 80 + 0.12

R50 = 80.12 ohms

So the winding resistance of the shunt generator at 50°C is 80.12 ohms.