Question

A 150 km, 3θ , 60Hz transmission line delivers power to a 15MW load at 66KV and at 0.85 P.d lagging. The line resistance per km is 0.2Ω, the line reactance per km is 0.7Ω and the capacitive admittance per km is 2.7x10⁻⁴ siemens. Calculate:

The sending end current

Answer 1

To calculate the sending end current, use the formula Is = P / (√3 * Vs * PF) and substitute the given values to find the current.

Step-by-step explanation:

The question involves calculating the sending end current for a power transmission system. To find this, one must use the power formula P = VI* cos(φ), where P is the power in watts, V is the voltage in volts, I is the current in amperes, and cos(φ) is the power factor. To calculate the sending end current, we can use the formula:
Is = P / (√3 * Vs * PF)
Where:

• P is the load power, which is 15 MW
• Vs is the sending end voltage, which is 66 kV
• PF is the power factor, which is 0.85 lagging

Substituting these values into the formula, we get:

Is = 15,000,000 / (√3 * 66,000 * 0.85)

Solving this equation, the sending end current is approximately 192.54 A.