Evaluation of low frequency communication techniques for load phase identification

This is a discussion on the process of implementing a system for power line communication (PLC). A PLC system is desired as it will allow for phase identification of the load and the transmission of data from the load to a central receiver. There are two main processes in a PLC system: a communications protocol and signal coupling. The communications protocol involves the methodology employed for successful communication between the load and the receiver. Signal coupling involves coupling the communication signal onto the power line at the load and off of the power line at the receiver. A successful implementation of these two processes will establish a system for PLC. The methodology employed for communication between devices is frequency shift keying (FSK). FSK will allow for low frequency operation with minimal attenuation. There are various coupling strategies that are presented for discussion. It is found that magnetically coupling a communication signal should be avoided and that a directly coupled signal generator should be implemented.