Power Line Carrier Coupling - A New Look at the Tuned Type

The major objectives of this paper are to show how a properly tuned coupling network may be selected, how the appropriate component values may be determined, and how the network may be accurately tuned. Two new concepts relative to power line carrier coupling are introduced. The first deals with the establishment of workable limits for the range over which the coupling network may be detuned by 60-Hz bus conditions (while still meeting transmission objectives), and the second shows means for evaluating the effect of the coupling unit (return loss) upon the standing wave ratios in the wire line as well as in the entrance cables. The resulting tuned coupling network has the following characteristics: 1) performance unaffected by substation bus conditions at the point of coupling; 2) predictable bandwidth and band location; 3) low coupling loss (less than ¿dB) from entrance cable to phase wire; 4) smooth frequency response (high return loss) over the derived band; 5) high blocking loss (greater than 25 dB) from phase wire to substation bus.