Power Line Communication as a Sensor: Medium Voltage Cable Diagnostics

Abstract

This article explores the secondary use of power line communication (PLC) technology, specifically broadband power line (BPL), as a diagnostic tool for medium voltage (MV) cable lines. Through experimental measurements, it was confirmed that selected communication parameters of BPL modems exhibit measurable deviations in the presence of partial discharge (PD) activity. Specifically, the parameters considered are throughput, signal-to-noise ratio (SNR), link capacity, bit load estimate (BLE), transmission amplitude map, Tonemap (modulation scheme), and Tonemask. In particular, BPL throughput decreased by approximately 10 Mbps for 100 pC PD and by around 50% for 1,000 pC PD. Since partial discharges are an early indicator of insulation system degradation, their detection supports predictive maintenance and contributes to improving the operational reliability of distribution networks. The results demonstrate that PLC/BPL technology–originally designed for communication and automation of distribution transformer stations (DTS)–can also serve as a cost-effective and readily deployable sensor system for real-time monitoring of cable health, without the need for dedicated diagnostic equipment. Experiments employing both inductive and capacitive couplers confirm the effectiveness of this secondary application in detecting insulation-related anomalies.