Grid diagnostics: Monitoring cable aging using power line transmission

Power line communication (PLC) operates on the power line infrastructure to enable data exchange between terminals. In doing so, PLC modems transmit relatively high-frequency and broadband signals through the grid. It is easy to see that the distortion of these signals provides information about the physical properties of grid components affecting the transmission. This is the basis for performing grid diagnostics as a secondary or even as the primary application of PLC. In this paper, we investigate the question whether broadband PLC can be used to detect cable aging, which is an important task for grid maintenance. We apply a physical model for the degradation of serviced-aged cables due to water treeing, and investigate its detectability using channel frequency responses as experienced by PLC signals. The latter is illustrated through the study of frequency-response variations in a small power line network and accomplished through classification with a support vector machine. Our numerical results are encouraging in that some water-treeing degraded and intact cables can be differentiated.