-ve and +ve sequence measurements
-ve and +ve sequence measurements
(OP)
What is the practical way to measure the –ve and +ve sequence impedances of a 138 kV ,52 km long over head transmission line installed on wooden towers , what is the technical specifications of the equipment needed for this test ?






RE: -ve and +ve sequence measurements
For short transmission line (length <80 kM ~ 50 mi) the Z+ = Z- is equivalent to the voltage measured at the receiving-end (load side) when excited at the sending-end side with a balanced 3-phase voltage source with current of 1 Amp circulating at the receieving-end short-circuited lines.
OBSERVATION:
i- For short transmission line, the two-port network parameter B = Z = R + j.X
ii-For short circuit at the receiving end (Vr =0).
iii-From the generalized equation
Vs = A.Vr+ B.Ir= Z.Ir
Therefore, for Ir=1Amp, |Z |= Vssc with an angle= (I<V)