Single Phase Overhead Transmission line

[smorc]

In a multi-grounded 7.620 kV line to ground Overhead Transmission line, what's the formula in computing voltage drop and power loss along the line? say for example the line is 3 kms using #2 AWG ACSR cable for primary line and #4 AWG ACSR cable for neutral line with 25 kVA transformer at load end.

 

[dpc]

Unfortunately, it's not that simple. Voltage drop will depend on the inductance of the single phase line and this is a function of the physical construction of the line.

Also, it depends somewhat on the power factor of the load.

In addition, the load at the end is generally dependent on the voltage, so some iteration is required for an exact solution.

You should be able to get the information you need to do the calculation from the Standard Handbook for EE.

Having said all that, a 25 kVA load isn't going to cause much voltage drop on 3km of 7620 V line. At the full 25 kvA, your primary current is only about 3.3 amps. This should not cause enough voltage drop to worry about.