Short transmission lines:
Here sending current is equal to receiving current .But sending & receiving voltages are not equal to due to impedance voltage drop in the transmission line.
Vs=Vr+IZ
Receiving end voltage lag by angle with respect to sending end voltage. In practical situation step-up and step –down transformer is used at sending end and receiving end of the transmission line as below.
Therefore total impedance can be implemented as Z=ZT1+ZL+ZT2
This can be equivalent to single phase circuit as below and transformer impedance can be assumed as series impedance.
