Longitudinal induction voltage measurement on communication cables running parallel to overhead lines

Overhead lines carrying electrical currents induce voltages in other parallel lines and cables. The induced voltage, otherwise known as low frequency induction (LFI) can result into malfunction and damage of the connected instrument and can endanger lives of people coming into contact with these conductors. Eliminating the effect of induced voltages is practically not possible in most occasions, because the communication cables normally run in the same easement and corridor used by electrified overhead lines, and in many cases utilize the same towers. Engineers must ensure the power system is designed in such a way that induced voltages on adjacent conductors are kept within the acceptable limits, safe for humans and connected equipment. The design can only be proven by commissioning tests once the power and communication systems are ready to be put in service. This paper intends to briefly explain methods by which the longitudinal induced voltage can be measured and introduce a new method for this measurement.