Configurations to introduce carrier signals into the electrical power system

Transmission and distribution lines are becoming a medium to transmit information. A spare bandwidth, a group of rules sets in laws and coupling equipments have been necessaries to have several practical applications. Thus, this paper is centered in the analysis of different coupling circuits. Besides, special attention has been made in the empiric results obtained in the research carried out to study the single high impedance fault, with a superimposing tone over a carrier that is synchronized with the main signal of the power system.