# three phase transmission line problem

*label*Mathematics

*timer*Asked: Feb 27th, 2016

**Question description**

A three-phase transmission line having a reactance of 120 ohms per phase is

connected to a wye-connected load whose resistance is 160 ohms per phase. If the

supply voltage is 70 kV line-to-line, calculate:

(a) The line-to-neutral source voltage.

(b) The line current per phase.

(c) The real and reactive power supplied to the load.

(d) The real and reactive power absorbed by the line.

(e) The line-to-line voltage at the load.

(f) The voltage drop per phase in the line.

(g) The total apparent power supplied by the source.

(h) The total real and reactive power supplied by the source.

3) A transmission line which is 300 miles long has a reactance of 240 ohms per phase

and a line-to-neutral capacitance of 600 ohms per phase. The equivalent circuit per

phase can be approximated by the circuit shown in Figure 3.

(a) If the line-to-line voltage at the sender S is 330 kV, what is the line-to-line voltage

at the receiver end R when the load is disconnected?

(b) Calculate the reactive power of the source in kVAR. Is this power supplied or

absorbed by the source?