The Research Of Noise Offset In Medium Voltage Power Line Communication

This thesis introduced a general model of the power line channel noise, and made an analysis of the frequency and time domain of the noise data gathered from the medium-and-low-voltage power line. The correlation calculation of the medium voltage power line noise and the establishment of the noise correlation model are the focus points. Then the correlation theory has been studied with symmetrical method, and the conclusion that three-phase system noises are associated was drawn. According to the consistency of two-phase noises, the noise offset is achieved through the transversal filter based on adaptive least-mean-square error (LMS) algorithm. Because transversal filter has a slow speed of convergence and is lack of follow-up learning ability, the LMS Adaptive Lattice Algorithm was used. Simulation studies have shown that noise offset method has increased effectively the signal-to-noise ratio of the 10kV medium voltage power line. It provided a new way for the automation of the 10kV distribution network with the carrier communication technology.