THEORY BEHIND POWER-LINE COMMUNICATION TECHNIQUE

THEORY BEHIND POWER-LINE COMMUNICATION TECHNIQUE

Power-line Carrier (PLC) is a communication technique that uses the existing power wiring (120 Volts, 240, etc…) to carry information. A "wireless" means of communication, PLC technology supersedes the installation of dedicated wiring.

PLC can convey analog information (e.g., voice in a PLC intercom) or digital information (e.g., data or control information in a Home Automation system).

Implementing high-level networking functions, the PLC is a digital or analog transmitter and receiver Integrated Circuit, or "transceiver IC" for short, that superimposes digital information (i.e., bits) over the electrical power flowing through the wiring of a house or building (see the figure on the right

Basic PLC System"Basic" PLC system consists of three distinct parts:

(a) The terminal assemblies, consisting of the transmitters, receivers, and associated components.

(b) The coupling and tuning equipment, which provides a means of connecting the PLT terminals to the high-voltage transmission line.

(c) The high-voltage transmission line, which provides the path for transmission of the carrier energy.

High-voltage coupling capacitors are used to couple the carrier energy to the transmission line, and simultaneously block 50-Hz power from the carrier equipment.