On-line Detection of Transmission Line Deterioration Using Power Line Communication Signal in Low-voltage Distribution Networks

In this paper, we propose an on-line detection method for transmission line deterioration by using power line communication (PLC) signals in the distribution network of low-voltage power system. In order to prove the feasibility of this method, firstly, we analyze the process of PLC and the conditions to be satisfied in theory. Secondly, we analyze two kinds of common transmission line deterioration: weak cable insulation and bad line switch contact. We give the models of these two cases and analyze the characteristics of PLC signals when these two kinds of deterioration occur. Thirdly, we use fast Fourier transformation (FFT) algorithm to analyze the extracted signal in frequency domain and get frequency domain properties. Finally, we use these properties to identify types of deterioration. Simulation results verify the reliability of this method.