M.Ing. (Electrical Engineering Science) / In today's rapidly changing technological environment, more and more importance is being attached to producing products as small as possible to save space as well as materials. Systems today use a wide range of signals, from those used to transmit energy, to small signal electronic signals used for control purposes. As these signals are not very compatible, they must each have their own cable harness to prevent unwanted interference between the signals. As a first step to reducing system size, the control signals (or any signal containing information) may be transmitted on the power transmission line, using techniques investigated in this dissertation. Systems using the same conductors for simultaneous energy and data transmission have many applications ranging from high tech systems to low cost rural communication. Examples of systems where this technology can be applied include: (a) distributed high frequency power systems, where switching of remote equipment can be done from a central point; (b) communication and control in harsh environments such as mining complexes, where switching of fans and motors for example can be done from a central point, while a communication network can be established by placing the information signals on the power cables; and (c) flexible manufacturing cells, where robots can be controlled via the power transmission harness. On the other hand, rural communication systems can be realised over the 50 Hz utility transmission network in remote areas. Such a system has the advantage of offering a low cost solution to providing access to communication to a large number of people spread over a large area. The work described In this dissertation covers two systems, firstly information transmission over the 50 Hz utility network and secondly, the design of a high frequency distributed power system utilising simultaneous information transmission on the transmission line.The first three chapters give an introduction to the technology and discuss the theory which must be applied to make simultaneous energy and information transmission over one conductor viable. Chapter 4 discusses the 50 Hz utility network as an information distribution network. The advantages and disadvantages are discussed, while some solutions are proposed how the disadvantages can be overcome. Chapter 5 discusses a high frequency distributed power system using simultaneous information transmission. The converter design is discussed, while some special design considerations are given which are essential to successful simultaneous information transmission in such a distributed system. To help with the design of the converter used, a simulation was carried out to predict the voltage and current waveforms in such a converter, the results of which can be seen in Appendix B.. The aim of simultaneously transmitting energy and information on the same transmission line was realised in both cases. In the 50 Hz system it was shown that adding external networks to guide the information carrier around obstacles such as 50 Hz power transformers improved the information transmission. A distributed power system however does not need external elements as long as the design of transformers follows the special considerations as described in chapter 5.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:12210 |
| Date | 03 September 2014 |
| Creators | Stielau, Dieter Ewald |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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