Paper presents technical limitations and constraints of high-voltage power-lines for high-speed digital PLC communications. Signal reflection and noise characteristics are recognized as major technical limitations for digital PLC system development. Results from a computer model and measurements are presented. Proposed solutions are at the end.

The presented integrated communication model corresponds to a computer simulation model used for computation of communication characteristics of an arbitrary HV overhead power-line channel. The simulated characteristics are suitable for analysis of the digital communications techniques application for highspeed data transmission over HV power lines. The integrated model is implemented as Matlab’s toolbox. The simulation results are compared with actual measurements of 400 kV power line.

The performance of bit interleaved turbo coded modulation (BITCM) technique in the power line channel and comparison with AWGN channel is presented. The noise characteristics are given for normal operations of power line network and foul weather condition. The model of power line channel including impulse noise is appropriated for investigation of channel coding methods. The bit error rate (BER) of M-ary quadrature amplitude modulation over PLC channel is given and represents the starting point for coding gain estimation. The BITCM system model is based on QAM mapping. The error rate performance obtained by computer simulation gives the basic characteristics of BITCM in communications over power line.

The paper presents the algorithm for estimation of frequency and time characteristics of the corona noise in high voltage power-line carrier (PLC) communications. In the frequency domain corona noise is represented with power spectral density and with Gaussian noise voltage with variable root mean square (RMS) value in time domain. The analytic method for estimation of the corona noise appearing at the line terminals in frequency and time domain is given. Simulations results are compared with the measurements on actual 400 kV power line.

The design of digital communication systems via overhead high voltage power-lines, namely digital power line carrier (dPLC), requires knowledge of the power-line high frequency characteristics. The paper derives an analytical formulation for high-voltage power-line high-frequency characteristics: amplitude and phase characteristics and group delay. Analytical expressions are derived for a power-line with three conductors in horizontal disposition and middle phase to ground coupling. These characteristics can be obtained numerically. On the other hand, the analytical description provides the nature of the media.

This paper presents an experimental and theoretical research of power line noise performed on overhead power line. High voltage (HV) power line, as a communication media, is a source by itself of different noises characterizing an important signature of this communication media. Investigation of appropriate channel coding techniques by computer simulations requires transfer characteristics of channel and statistical model of noise. In this paper, the computer model of power line noise is presented. A simulation of the noise is carried out in Matlab.

This paper presents a major high-frequency characteristic of high-voltage overhead power line: amplitude characteristics, group delay and noise characteristics. Since measurements of high-frequency power-line characteristics are rare due to permission of power utilities for access to power lines, computer simulations have a crucial role in design of communication systems via power lines. Simulated high-frequency and noise characteristics of 400 kV power line are presented and compared with measurements on actual power line.