A framework for energy in South Africa with special reference to a long term forecast for energy demand
- Authors: Cooper, Christopher John
- Date: 2015-02-09
- Subjects: Force and energy , Power resources
- Type: Thesis
- Identifier: uj:13217 , http://hdl.handle.net/10210/13243
- Description: M.Phil. , The construction of mathematical models for making projections of future energy demand is an important step in the formulation of an energy policy for a country or region. In this dissertation the different approaches to energy modelling are investigated. The history of the modelling effort in the world and South Africa is briefly discussed. The development of a comprehensive database is of vital importance for the success of any modelling effort. An energy database for South Africa was developed. An existing energy forecasting model was updated and extended to cover eleven final consuming sectors. Projections of energy demand were made to illustrate the mechanism of the model.
- Full Text:
- Authors: Cooper, Christopher John
- Date: 2015-02-09
- Subjects: Force and energy , Power resources
- Type: Thesis
- Identifier: uj:13217 , http://hdl.handle.net/10210/13243
- Description: M.Phil. , The construction of mathematical models for making projections of future energy demand is an important step in the formulation of an energy policy for a country or region. In this dissertation the different approaches to energy modelling are investigated. The history of the modelling effort in the world and South Africa is briefly discussed. The development of a comprehensive database is of vital importance for the success of any modelling effort. An energy database for South Africa was developed. An existing energy forecasting model was updated and extended to cover eleven final consuming sectors. Projections of energy demand were made to illustrate the mechanism of the model.
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The performance of distance protection relay on series compensated line under fault conditions
- Magagula, X. G., Nicolae, Dan-Valentin, Yusuff, A. A
- Authors: Magagula, X. G. , Nicolae, Dan-Valentin , Yusuff, A. A
- Date: 2015
- Subjects: Distributed generation of electric power , Power resources , Energy development
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17172 , uj:15850 , ISBN 9781479974979 , Citation: Magagula, X., Nicolae, D.V., & Yusuf, A.A. 2015. The performance of distance protection relay on series compensated line under fault conditions. In: Proceedings of the Africon 2015, 14-19 September 2015, Addis-Ababa:630-635 , ISBN:9781479974979
- Description: Abstract: This paper presents the behaviour of the distance protection relays on a series compensated transmission line under fault conditions. Series compensation presents distance protection elements with unorthodox line impedance and as a result the relays may operate incorrectly. Sub-harmonic oscillations and non-linearity of the line impedance are some of the challenges introduced by series compensation of transmission lines. The study is carried out in a Digsilent power factory environment and results pertaining to the response of the distance relay on a 400 kV series compensated line under fault conditions are presented
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- Authors: Magagula, X. G. , Nicolae, Dan-Valentin , Yusuff, A. A
- Date: 2015
- Subjects: Distributed generation of electric power , Power resources , Energy development
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17172 , uj:15850 , ISBN 9781479974979 , Citation: Magagula, X., Nicolae, D.V., & Yusuf, A.A. 2015. The performance of distance protection relay on series compensated line under fault conditions. In: Proceedings of the Africon 2015, 14-19 September 2015, Addis-Ababa:630-635 , ISBN:9781479974979
- Description: Abstract: This paper presents the behaviour of the distance protection relays on a series compensated transmission line under fault conditions. Series compensation presents distance protection elements with unorthodox line impedance and as a result the relays may operate incorrectly. Sub-harmonic oscillations and non-linearity of the line impedance are some of the challenges introduced by series compensation of transmission lines. The study is carried out in a Digsilent power factory environment and results pertaining to the response of the distance relay on a 400 kV series compensated line under fault conditions are presented
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Transient stability analysis of VSC HVDC transmission with power injection on the DC-link
- Nnachi, Agha Francis, Munda, Josiah, Mpanda, Augustin Mabwe
- Authors: Nnachi, Agha Francis , Munda, Josiah , Mpanda, Augustin Mabwe
- Date: 2015
- Subjects: Power resources , Electric power transmission - Direct current
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17235 , uj:15862 , Nnachi, A.F. et al. 2015. Transient stability analysis of VSC HVDC transmission with power injection on the DC-link. Turkish Journal of Electrical Engineering & Computer Sciences,2015(23). DOI:10.3906/elk-1404-214.
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- Authors: Nnachi, Agha Francis , Munda, Josiah , Mpanda, Augustin Mabwe
- Date: 2015
- Subjects: Power resources , Electric power transmission - Direct current
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17235 , uj:15862 , Nnachi, A.F. et al. 2015. Transient stability analysis of VSC HVDC transmission with power injection on the DC-link. Turkish Journal of Electrical Engineering & Computer Sciences,2015(23). DOI:10.3906/elk-1404-214.
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Translational contactless power supply systems with ultrasonic frequencies
- Authors: Barnard, Jacobus Marthinus
- Date: 2012-11-27
- Subjects: Power resources , Electric current converters , Electric transformers
- Type: Thesis
- Identifier: uj:7412 , http://hdl.handle.net/10210/8242
- Description: D.Ing. , In this thesis, contactless power transmission with sliding transformers to mobile loads is investigated. The sliding transformer comprises an extended primary winding - placed along the path of travel - which is fed through a core containing a secondary winding and which is attached to a mobile load. In the first chapter problems with existing power supply systems are discussed whereafter several possible applications of such a system are identified. In this chapter different methods of obtaining contactless power transmission are also discussed and a brief discussion of a practical, cost effective system is given. In chapter two the application of different resonant topologies to compensate the large structural inductance of the sliding transformer is investigated. A Series Resonant, Series Loaded topology is identified as the most practical and efficient topology for this application and a more detailed analysis of this topology - as applied to this case - is given. Formulas to calculate the sliding transformer parameters are given in the third chapter and two quantities relating the optimization of sliding transformers to the parameters thereof, are defined. Methods to optimize sliding transformers in terms of these two quantities, and also with respect to EMI, are also discussed in this chapter. The design of a five meter long experimental system which delivers 15 kVA to a mobile load is given in chapter four and experimental results of this system are presented. In chapter five a detailed investigation into different output power control methods is conducted. The effect of these control methods on EMI is investigated by means of numerical simulation of a Series Resonant, Series Loaded system under these different control methods. The most complex control method which generates the most EMI, namely frequency and pulse burst control, is implemented into the experimental system to investigate the limitations thereof. Experimental results of this controlled system are presented. It is found that this control method increases the control range obtainable with classical frequency control but introduces many limitations due to discontinuous primary current. It is concluded in the last chapter that it is possible to optimize sliding transformers within achievable cost constraints to such an extent that such systems have acceptable efficiencies and that reasonable system lengths are obtainable.
- Full Text:
- Authors: Barnard, Jacobus Marthinus
- Date: 2012-11-27
- Subjects: Power resources , Electric current converters , Electric transformers
- Type: Thesis
- Identifier: uj:7412 , http://hdl.handle.net/10210/8242
- Description: D.Ing. , In this thesis, contactless power transmission with sliding transformers to mobile loads is investigated. The sliding transformer comprises an extended primary winding - placed along the path of travel - which is fed through a core containing a secondary winding and which is attached to a mobile load. In the first chapter problems with existing power supply systems are discussed whereafter several possible applications of such a system are identified. In this chapter different methods of obtaining contactless power transmission are also discussed and a brief discussion of a practical, cost effective system is given. In chapter two the application of different resonant topologies to compensate the large structural inductance of the sliding transformer is investigated. A Series Resonant, Series Loaded topology is identified as the most practical and efficient topology for this application and a more detailed analysis of this topology - as applied to this case - is given. Formulas to calculate the sliding transformer parameters are given in the third chapter and two quantities relating the optimization of sliding transformers to the parameters thereof, are defined. Methods to optimize sliding transformers in terms of these two quantities, and also with respect to EMI, are also discussed in this chapter. The design of a five meter long experimental system which delivers 15 kVA to a mobile load is given in chapter four and experimental results of this system are presented. In chapter five a detailed investigation into different output power control methods is conducted. The effect of these control methods on EMI is investigated by means of numerical simulation of a Series Resonant, Series Loaded system under these different control methods. The most complex control method which generates the most EMI, namely frequency and pulse burst control, is implemented into the experimental system to investigate the limitations thereof. Experimental results of this controlled system are presented. It is found that this control method increases the control range obtainable with classical frequency control but introduces many limitations due to discontinuous primary current. It is concluded in the last chapter that it is possible to optimize sliding transformers within achievable cost constraints to such an extent that such systems have acceptable efficiencies and that reasonable system lengths are obtainable.
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Impacts of primary energy constraints in the 21st century
- Authors: Nel, Willem P.
- Date: 2010-03-25T06:25:17Z
- Subjects: Energy conservation , Energy development , Power resources , Fossil fuels , Nuclear energy , Sustainable development , Economic development , Global warming
- Type: Thesis
- Identifier: uj:6691 , http://hdl.handle.net/10210/3094
- Description: D.Phil. , Global society has evolved into a complex multi-dimensional system in which it has become increasingly difficult to construct and maintain a systemic model of cause and effect. Specialisation and abstraction in the various disciplines of scientific and societal complexity has led to divergent theories of sustainability. Failure to integrate real life problems across disciplines poses a threat to modern society because the causal links between disciplines are unattended in many instances and events in one dimension could lead to catastrophic unintended consequences in another. In light of the above, this thesis contributes towards the multi-disciplinary integration of some of the most important sustainability concerns of modern society, namely Energy Security, Economic Growth and Global Warming. Analysing these real-life sustainability issues in a multi-disciplinary context leads to conclusions that are controversial in terms of established philosophical worldviews and policy trends. Firstly, the thesis establishes deterministic expectations of an imminent era of declining Energy Security resulting from the exhaustion of non-renewable fossil fuel resources, despite optimistic expectations of technology improvements in alternative energy sources such as renewable and nuclear. Secondly, the exhaustion of non-renewable fossil fuel resources imposes limits to the potential sources of anthropogenic carbon emissions that render the more pessimistic emissions cases considered in the global warming debate irrelevant. The lower level of attainable carbon emissions challenges the merits of the conventional carbon feedback cycle with the result that the predicted global warming is within acceptance limits of the contemporary global warming debate. Thirdly, the consequences of declining Energy Security on socio-economic welfare is a severe divergence from historical trends and demands the reassertion of the role of energy in human development, including Economic Growth theory. The thesis develops a novel economic growth model that treats energy as an explicit and Autonomous Factor of Production, thereby facilitating plausible predictions of future Economic Growth potential. The results challenge the sustainability of the current free-market capitalist economic system and demand strong policy responses to avoid the collapse of modern society.
- Full Text:
- Authors: Nel, Willem P.
- Date: 2010-03-25T06:25:17Z
- Subjects: Energy conservation , Energy development , Power resources , Fossil fuels , Nuclear energy , Sustainable development , Economic development , Global warming
- Type: Thesis
- Identifier: uj:6691 , http://hdl.handle.net/10210/3094
- Description: D.Phil. , Global society has evolved into a complex multi-dimensional system in which it has become increasingly difficult to construct and maintain a systemic model of cause and effect. Specialisation and abstraction in the various disciplines of scientific and societal complexity has led to divergent theories of sustainability. Failure to integrate real life problems across disciplines poses a threat to modern society because the causal links between disciplines are unattended in many instances and events in one dimension could lead to catastrophic unintended consequences in another. In light of the above, this thesis contributes towards the multi-disciplinary integration of some of the most important sustainability concerns of modern society, namely Energy Security, Economic Growth and Global Warming. Analysing these real-life sustainability issues in a multi-disciplinary context leads to conclusions that are controversial in terms of established philosophical worldviews and policy trends. Firstly, the thesis establishes deterministic expectations of an imminent era of declining Energy Security resulting from the exhaustion of non-renewable fossil fuel resources, despite optimistic expectations of technology improvements in alternative energy sources such as renewable and nuclear. Secondly, the exhaustion of non-renewable fossil fuel resources imposes limits to the potential sources of anthropogenic carbon emissions that render the more pessimistic emissions cases considered in the global warming debate irrelevant. The lower level of attainable carbon emissions challenges the merits of the conventional carbon feedback cycle with the result that the predicted global warming is within acceptance limits of the contemporary global warming debate. Thirdly, the consequences of declining Energy Security on socio-economic welfare is a severe divergence from historical trends and demands the reassertion of the role of energy in human development, including Economic Growth theory. The thesis develops a novel economic growth model that treats energy as an explicit and Autonomous Factor of Production, thereby facilitating plausible predictions of future Economic Growth potential. The results challenge the sustainability of the current free-market capitalist economic system and demand strong policy responses to avoid the collapse of modern society.
- Full Text:
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