Line to Line Coupling

Line to Line Coupling :-

✥Some applications will require more dependability. When the protected line is of significant importance and the type of protection requires receipt of the signal during an internal fault, multiphase coupling improves dependability of the signal being transmitted through the fault.

✥Since the most frequent type of power system fault is a phase to ground, you can improve your chances of receiving the signal through the fault if more than one phase is used.

✥As shown in the fig. in case of line to line coupling any two line conductors can be used for transmitting a carrier signal as well as receiving the carrier signal over a section of the transmission line.

✥In this case the carrier signal travels through the line conductors and the surrounding medium is air between the conductors. Therefore the attenuation is very less.

✥Therefore it offers much better performance during single line to ground faults.

✥This type of transmission mode is also known as aerial mode of transmission.