Thesis (M.S.)--Ohio University, June, 2005. / Title from PDF t.p. Includes bibliographical references (p. 86-88)

Thesis (MScIng)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

Since democratisation of South Africa in 1994, the economy of South Africa underwent significant structural changes. Among these structural changes was electrification for the poor rural areas. During the apartheid era, about two-thirds of the nation lacked access to electricity and hence, provision for electricity to everyone was considered a crucial part of the economic development, post 1994. Since then economic growth and the demand for electricity in South Africa have been increasing at an unprecedented rate. The electricity supply did not increase proportionally to the increase in the consumption of electricity. In responding to the high increase in the demand for electricity, the electricity utility planned to build new power stations and put back in use the ones which were mothballed. But unfortunately the plan for investment in these power stations was late and in 2008, the existing power stations could not manage to supply enough electricity. The demand for electricity was such that it nearly damaged the power generating circuit and the electricity supply utility had to resort to load shedding. The imbalance between electricity supply and demand led to industrial sectors losing on production and as a result led to a downturn in economic growth. It also led to an increase in electricity prices which had a negative effect on individual and private sectors’ purchasing power. It is against this background that this study is designed to investigate the long term relationship between economic growth and electricity supply. The additional variables such as electricity prices, trade openness, capital and employment were included as intermittent variables to form a multivariate framework. This study also assesses the Granger causality between these variables to determine which variable supersedes the other. Two models were applied in this study: The Auto-regressive Distributed Lag (ARDL) bounds approach and the Vector Error Correction Model (VECM) Granger-causality. The ARDL bounds technique was used to detect the long term relationship between economic growth, electricity supply, electricity prices, trade openness, capital and employment using annual data from 1985 to 2014. The ARDL technique was chosen over the conventional models such as Engle and Granger (1987) and Johansen (1988) for the research for the following reasons: Firstly, the ARDL technique uses a single reduced form of equation to examine the long term relationship of the variables as opposed to the conventional Johansen test that employs a system of equations. Secondly, it is suitable to use for testing co-integration when a small sample data is used. Thirdly, it does not require the underlying variables to be integrated of similar order e.g. integrated of order zero I(0), integrated of order one I(1) or fractionally integrated, for it to be applicable. Lastly, it does not rely on the properties of unit root datasets and this makes it possible for the Granger-causality to be applied in testing the long term relationships between the variables. The VECM Granger-causality is used to examine the Granger-causality between the chosen variables. It was chosen for its ability to develop longer term forecasting when dealing with an unconstrained model. The unit root results confirmed that the variables were stationary at first difference using Augmented Dickey Fuller (ADF), Phillips and Perron (PP) and Kwiatkowski-Phillips-Schmidt-Shit (KPSS). The ARDL bound approach outcomes revealed that economic growth, electricity supply, trade openness, electricity prices, employment and capital move together in the long term. There were three co-integrated equations under the export and trade models while under the import model there was one co-integrated equation. The results are such that electricity prices have a negative impact on economic growth. The results further evidenced that; electricity supply, trade openness, employment and capital have a positive impact on economic growth in the long term. The VECM Granger causality findings suggested a unidirectional causality flowing from electricity supply, trade, exports, electricity prices, employment and capital to economic growth in the long term. There was another unidirectional causality established flowing from economic growth, trade openness, electricity prices, employment and capital to electricity supply. A one-way causality flowing from economic growth, electricity supply, electricity prices, employment and capital to export was evidenced. Overall, the study’s results of bidirectional Granger-causality between electricity supply and economic growth have a number of implications for forecasters and policy makers. This feedback hypothesis implies that the high level of economic growth leads to a high level of electricity supply, which would stimulate economic growth. Hence, South Africa demonstrates a kind of electricity dependence in a manner that a sufficiently large supply of electricity seems to ensure high economic growth. Electricity supply is a vitally important factor for economic growth in South Africa. It is therefore necessary that South African policy makers formulate investor friendly policies that will encourage, promote and attract capital inflows to stimulate electricity supply. The South African government needs to primarily deregulate the electricity supply industry which is owned by Eskom (a monopoly), and allow more investors into this industry. The government should promote a change to other forms of energy sources such as renewable energy sources which will play an important role in restoring the balance between electricity supply and consumption. Moreover, it is recommended that the electricity regulator should take steps to curb the severe electricity price increases and to ensure prices affordable to the poor communities. The policy makers need to implement some investor friendly policies that will encourage and promote capital formation. Furthermore, the government should invest towards more job creating sectors such as (Small and Medium Enterprises) SMEs. Finally, the government should take into consideration the importance of trade openness to attract international investments into the economy. It is hoped that the findings of this study would prove beneficial to policy makers in South Africa and elsewhere in the world where power outages are experienced, and assist them in combating the problem.

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A dissertation submitted in partial fulfillment of the Master's Diploma in Technology: Electrical Engineering (Heavy Current), M.L. Sultan Technikon, 1998. / With the ever increasing electrical demand on an electrical system, the quality of the supply will be tested more and more. And it is with this deteriorating quality that the topic of voltage dips and depressions has become a contentious issue amounts the industrial sector and supply authorities, hence the means to combat this issue in recent years. / M

Data pertaining to the number of failed high voltage current transformers installed in / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2006. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2006.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2005. / The cause of the largest number of faults on the Eskom main transmission system is unknown. It is believed that a non-uniform pollution layer along an insulator string is the reason for these anomalous flashovers. This non-uniform pollution layer results in the highest electric field strength, and thus the highest voltage, across the cleanest and driest discs. There thus exists a strong possibility that the anomalous flashover phenomenon is caused by a combination of mechanisms involving the pollution and air breakdown flashover mechanisms. This research project attempted to prove that flashover of the insulators is possible in accordance with the above model. Various experiments were set up in the high voltage laboratory and at a natural test site with a low source impedance supply attempting to simulate the conditions that lead to flashover in accordance with the hypothesis. All the tests done have not proven the non-uniform light pollution flashover mechanism successfully. However, future research has proposed an air breakdown flashover mechanism in light pollution conditions where the polluted part of the insulator string has a specific non-uniform distribution. Full scale testing in conditions similar to the normal operating conditions is proposed to prove the validity of this new hypothesis.

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

Submitted in fulfillment of the requirements for the degree of Master in Technology, Durban University of Technology, Durban, South Africa, 2015. / The primary objective of this research was to investigate the failures occurring in the family of surge arresters used within EThekwini Electricity, making use of different diagnostic methods, such as leakage current testing (LC), infrared scanning (IR), and partial discharge (PD) measurements. The different diagnostic tests were used to assess the degradation process of the polymer housed surge arresters and their failure. The measurements were used for diagnosis of 120 kV/65 kA surge arresters of different brands. Tests were performed on surge arresters that were still in the system and these test results were compared with results from tests performed on failed units. Results obtained from the different tests were compared to the test results for different families or designs. An imperfect arrester will exhibit excessive heating when an electrical surge is discharged. The aforementioned tenets are the primary factors influencing degradation and causing failure of Metal Oxide Surge Arrester (MOSA) in a system. These factors can decrease creepage and flashover distance on insulation, which could result in a substantial increase in resistive leakage current, (which is a few microamperes in ideal condition), overheating, and PD formation on the zinc oxide varistor element. Therefore, it is extremely important to assess the status of the surge arresters whilst they are in service, firstly so that they can be removed from the system before they fail and, and secondly, to verify their condition, and their ability to effectively protect the substation apparatus. Using infrared inspection, valuable information of condition of surge arresters was obtained, heat inside the surge arresters was detected and this shows that IR analysis can therefore be considered as an additional method to assess the condition of polymer housed surge arresters. It was observed that partial discharge activity is an indication of degradation in arrester varistor. LC test, IR, and PD measurement were valuable in obtaining sufficient information for failure of surge arresters. In additional, during the visual internal inspection of arresters, evidence of punctures, treeing, tracking, and moisture masks were noted on ZnO blocks and seals. These results indicate that the moisture ingress through the sealing collar can cause unnecessary outages. / M

No description available.