Present trends toward long distance extra high voltage transmission lines and static excitation can cause a reduction in the stability margins of a typical power system unless measures are taken to improve the system damping. Practical applications of stabilizing signals are investigated in this thesis and limitations of the design techniques discussed. An optimal control signal is derived from modern control theory. All signals are obtained from a common linearized power system and the performance is tested for large disturbance conditions on a single machine-infinite bus system where the machine, exciter and governor are represented in detail. Both types of signals are also tested on a practical four machine system model and it is shown that a similar improvement in damping can be obtained with either a stabilizing signal derived using conventional frequency response techniques or a proportional feedback controller obtained from solution of the algebraic matrix Riccati equation. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

A stable and reliable electrical power supply system is an inevitable pre-requisite for the technological and economic growth of any nation. Due to this, utilities must strive and ensure that the customer’s reliability requirements are met and that the regulators requirements are satisfied at the lowest possible cost. It is known fact around the world that 90% of the customer service interruptions are caused due to failure in distribution system. Therefore, it is worth considering reliability assessments as it provides an opportunity to incorporate the cost or losses incurred by the utilities customer as a result of power failure. This must be considered in the planning and operating practices. The system modelling and simulation study is carried out on one of the district’s distribution system which consists of 132 kV, 66 kV and 22 kV network in Aliwal North Sector ECOU. The reliability assessment is done on the 22, 66 and 132 kV system to assess the performance of the present system and also predictive reliability analysis for the future system considering load growth and system expansion. The alternative which gives low SAIDI, SAIFI and minimum breakeven costs is being assessed and considered. The reliability of 132 kV system could be further improved by constructing a new 132 kV line from a different source of supply and connecting with line coming from another district (reserve) at reasonable break even cost. The decision base could be further improved by having Aliwal North Sector context interruption cost. However, the historical data which may be used in Aliwal North Sector to acquire interruption costs from the customers are being proposed. The focus should be on improving the power quality on constrained networks first, then the reliability. Therefore for the Aliwal North power system network it is imperative that Eskom invest on the reliability of this network. This dissertation also analysed load reflected economic benefit versus performance expectations that should be optimized through achieving a balance between network performance (SAIDI) improvement, and total life cycle cost (to Eskom as well as the economy). Reliability analysis conducted in this dissertation used Aliwal North power system network as a case study; the results proved that the system is vulnerable to faults, planned and unplanned outages. Reliability evaluation studies were conducted on the system using DigSilent software in conjunction with FME. These two models gave accurate results with acceptable variance in most indices except for the ENS where the variance was quite significant. It can be concluded that DigSilent results are the most accurate results in all three reliability evaluation scenarios for the Aliwal North Power System, best interpretation being that of DigSilent.

In partial fulfilment of the requirements for the degree of Master of Management in Finance & Investment Management. / This study examines the relationship between electricity infrastructure finance and the economic growth of Swaziland in an attempt to determine the extent to which electricity infrastructure contributes to economic growth. The study also examines what factors determine the level electricity infrastructure finance in Swaziland, and the extent of the influence of these factors. This study hopes to add to the body of literature focused on scrutinising the infrastructure investment challenges in the low-income countries of the African region, and the discovery of innovative financing mechanisms that will bring the region to a favourable position where it can supply reliable energy that promotes the prosperity of its people. Using annual data, trend analysis and OLS regression techniques are applied to determine the extent of the relationship between electricity infrastructure investment and economic growth, as well as the economic and regulatory factors expected to influence the level of infrastructure investment, as suggested by literature. The level of electricity infrastructure investment is found to be positively correlated with economic growth and the macroeconomic stability of Swaziland. However, little to no correlation is found between the level of electricity infrastructure investment, and government revenue, stock market capitalization, and credit extended to the government and parastatals. Regulatory quality is found to be negatively correlated to electricity infrastructure investment. / GR2018

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In this thesis, a general-purpose digital computer program to perform fault analyses is developed and discussed in detail. The program is utilized to perform a complete fault study of the distribution system of the VPI Electric Service, as an example test case. Equations are gathered and a computer program is written to calculate the fault current magnitudes on a distribution system when three phase, phase to phase, phase to phase to ground, or phase to ground faults occur. The program is written to include basic circuit types that are in use in the utility industry today. The program provides results that are in tabular form for easy use. The VPI Electric Service system is discussed and results are included for the major distribution circuits in the system. System maps have been prepared for the circuits and are available at the Electric Service. A user's guide is included so that the program can be used whenever system changes demand a new study. / Master of Science

Presented in this paper is a scheme for minimizing the cost function of a three-source technique to arrive at an approximation point (I,J) that is within one unit of the true minimum. The Line-Step algorithm is applied to several systems and is also compared to other minimization techniques, including the Equal Incremental Loss Algorithm. Variations are made on the Line-Step Algorithm for faster convergence and also to handle inequality constraints. / Master of Science

A project submitted to the faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfilments of the requirements for the degree of Master of science in Engineering Johannesburg, 1994 / The purpose of this document is to report on the development of Linear Programming function for the Generation Expansion Planning environment of Eskom. This was achieved by researching the modeling methods employed in this and related fields of work. After establishing the scope of the work to be performed all the options were carefully assessed and it was decided to develop the Production Scheduling function first, as this would serve as the foundation for future work. The requirements were specified after extensive discussion with the customer. These requirements were utilize to establish the formulae, including their bounds and constraints. These were in turn converted into the Linear programming function. To faci1itate the data input process a simple input facility was developed. To maximize the value of the results the report writer was developed to enable sensitivity studies to be performed. This work was later used as the foundation of the NewGex programme.

M. Tech. Electrical Engineering. / This dissertation presents an effective method to determine current/voltage harmonic emission levels caused by various devices in the network. The method is implemented based on the existing power monitoring devices installed in power generation plants. The Digital Fault Recorders (DFRs) are used in this work as the monitoring devices. Due to the advancement of data processing and communication capabilities of such devices, a large amount of information generated by DFRs is concentrated in the utilitys head office. This data is archived for permanent storage and analysis. The presented work aims to assist the power utilities in harmonic invigilation problems based on DFRs.

Do domestic variables matter in a context of bilateral cooperation? What factors positively influence the decision-making process in the case of a policy harmonization between two countries? By studying both countries' institutional differences and governmental and non-governmental actors' preferences in the energy sector, this research analyzes the bilateral cooperation between Canada and the United States regarding the creation of the Electric Reliability Organization. Although domestic institutional constraints are important to consider, I argue that both physical and economic market integration and the use of a non-governmental organization by central governments have facilitated the success of the cooperation process. Those factors have favored the convergence of decisional actors' preferences and the inclusion of the majority of actors from all sectors of the industry into the process. The analysis uses a sequential model implying the division decision-making process over foreign policy into specific stages to show the importance of domestic variables. / Key words: Governmental cooperation, bilateral relations, actors' preferences, institution, energy sector, electricity, transmission network, reliability standards, market integration, restructured electricity market.