In faults condition, the heavy current flux density(B) would be constant in saturation for large ampturn(AT) or inductive reactance(X=2(pia)flL, L= do/di)would be constant or Z=R plus X constant, & would be proportional to distance....

is true if the transmission line in radial in other case the impedance its an Zthv of the system

Hi Muhammad,

By having a closer look to the formulas of impedance components (i.e. R , XL):

1) R= r*L,

2) XL=x*L

r, and x are the impedance per km (Ω/km). We can notice that the impedance components R&XL increase proportionally with the L, where L is the total length of the electrical conductor (could be cable/line in LV, transmission line,...)

So the answer to your question is that the fault location can be located once the protection relays can characterise (measure) the transmission impedance correctly. Once the total impedance is measured, the fault location can be calculated since the values of r (Ω/km) and x (Ω/km) of the transmission line is well-known. Note that more consideration should be given also to the capacitance and mutually coupled transmission lines.

Because that all the electrical lines including power transmission lines have distributed parameters - resistance, inductance, capacitance, conductivity and impedance. Just their wave impedance does not depend on length.

A simple answer to the mentioned question is

"

Impedance is an electrical measure of distance along a transmission line."

refrence:book of power system analysis by vk mehtha chapter 21 page 511.

No doubt in electrical transmission line length is a function of impedance. Also it is one of the parameter to detect fault specially for under ground cables.( Ohm/km.)

But for low frequency transmission lines used for electronic devices length has low impact on impedance.