High Frequency Modelling of Powerline Distribution Networks.

Dickinson, John (1997). High Frequency Modelling of Powerline Distribution Networks. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.0000f5cb

Abstract

The purpose of this thesis is to investigate the available bandwidth for communications on electricity distribution networks. The work is concentrated on the low voltage parts of the network to maximise the use of that bandwidth and to model parts of the distribution system in order that the characteristics can be theoretically examined before practical on site investigation takes place.

The work begins by looking at the history of the subject, past and currently available systems, their methods of operation and their limitations.

The work continues by developing transmission line equations and transmission line parameters, for both single and multi phase, showing the implementation of these equations for power cables and distribution networks.

A comprehensive study of the topology and structure of the UK electricity distribution network is given in order to provide an understanding of the basic network elements which are interconnected to form a pervasive nationwide electricity transmission and distribution network.

Software listings are included in the appendices and an explanation of the mathematics and programming is included in chapters 3 and 7.

The initial investigations showed that low voltage distribution networks were noisy and that the noise levels, varied with time. These initial investigations also showed that power levels in the order of milliwatts would allow communications during low noise periods. This led to the development of the mains filter to prevent noise from customers' premises from entering the network. Fitting of these filters fixed the noise levels on the network and allowed the low power signals to be used.

After the filters are fitted to a network the parameters affecting the characteristics of that network are much simplified and fixed, providing no physical alterations take place. Because of this "fixing of the response" a computer analysis was thought to be an option that would allow the characteristics of any network to be calculated prior to practical installation. This has been done and the results are given in this thesis.