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The paper seeks to design, test and implement a fast transfer scheme for an existing Alpha Olefins substation at Sasol Secunda, Mpumalanga Province, in South Africa. The aim of this design is to switch motor bus bars over to an intact back up supply should the main supply fail and to switch them back again when the main supply is restored. The switchover to the back up supply must be performed as...
The requirement of detection and identification of the tabular structures from a Document Image is crucial to any DIA and digital library system. Here in this paper we report a generic approach to detect any tabular structure in any form that may be present in the document as table, tabular displayed math, table of contents page and index page without any OCR.
The Daily load shape has an intrinsic correlation with power dispatch and therefore, during the peak demand hours power systems need to operate on their maximum capacity. This paper describes how daily load profile of power systems interacts with power dispatch, driving the supply side to act in accordance with the trend in electricity demand of the consumers. The load curve has a strong dependence...
This paper reports on solar photovoltaic integration on locomotive roof tops for South African Railway industry. The notion is to minimize the electricity consumed by Transnet Freight Rail, a division of Transnet SOC. The operational route is chosen based on the geographical mapping of high temperatures in the country. Solar PV intended to be used will have the capability to withstand the South African...
Solar power is an attractive source of energy, free, abundant and not polluting the atmosphere. However, due to the low efficiency of current photovoltaic cells, conversion of sunlight into electrical power is very poor, and it is irradiance level, array temperature dependents, this efficiency further decreases if there is no impedance matching between photovoltaic panels output and the load to ensure...
Africa and particularly South Africa has an enormous potential for the use of renewable energy, more so, solar energy. Higher institutions of learning in South Africa have the potential to tap into renewable energy technologies to conserve energy, both on small-scale and even large-scale levels. The Centre for Energy and Electric Power (CEEP) at Tshwane University of Technology (TUT) is committed...
This paper reports on a study and analysis of parasitic impedances that affect the switching activity of the Forward converter having a high ratio of transformation. The presented Forward converter system is based on the component dimensioning for power output of 400Watts and input voltage of 12Volts. The main objective of this investigation is to determine the origin and location of parasitic impedances...
Modern utilities around the world have started the implementation of small scale local generation to support power supply. Introduction of distributed generation presents new challenges and opportunities for electrical engineers. One of the challenges is the change of network electrical characteristics. Network regulators have accommodated these changes in Grid Codes. One of the recent regulations...
This paper investigates the cost effectiveness of lighting technologies and their role in mitigating carbon emissions through a case study of a university student residence in Cape Town, South Africa. Different commercially available lighting technologies will be compared in terms of their energy consumption and associated costs (both running and installation costs) through Dialux Lighting simulations...
Quality of power supply into an electrical network is governed by grid codes, which place restrictions on the voltage characteristics, compatibility levels, limits and assessment methods. In most grid codes it is stated that overvoltage should not exceed 1.05 to 1.15 of the nominal value. Overvoltage is a common issue in networks with Photovoltaic (PV) generation. PV Plants generally have the highest...
This paper presents detailed modeling and design of a PV generator, capable of working in grid connected and islanded modes, using Simscape, Matlab software considering practical on-site condition such as constant and variable load condition including natural uncertainty due to varying irradiance situation etc. The steps of modeling of a sample PV generator is described in detail which will be useful...
The advent of phasor measurement units (PMU) has sparked the development of applications to accommodate synchronized measurements provided by PMUs. However, incorporating PMUs in a power system is a challenge because synchrophasor measurement technology (SMT) is a very limited resource and there are numerous applications competing for SMT measurements. How each application benefits from SMT is contingent...
A distribution network with embedded generation offers auxiliary benefits when compared to a traditional radial arrangement. However, as the penetrations of distributed generators intensify, power flow, fault current and direction adjust, inhibiting the coordination of traditional protection devices. Advanced methods have been developed to alleviate false tripping or protection blinding caused by...
Conventional protection schemes are unable to detect low fault current levels common in microgrids. A number of methods have been proposed in various research papers. Some of the recently proposed methods are the total harmonic distortion detection method, addition of a current source, abc-dq0 transformation method and the voltage constraint overcurrent method. Analysis of these methods is conducted...
Worldwide initiative to transform its energy industry from being based on polluting fossil-fuels into cleaner renewable energy resources is growing. Interest is growing in generating power using Concentrating Solar Thermal Power (CSTP) plants where solar energy is concentrated to heat a working fluid and run the turbine to generate electricity. The paper focuses on the selection process of thermal...
One of the serious problems that the world still faces nowadays is the chronic power shortage and the inaccessibility to energy services of mostly the majority of the population living in remote or off-grid areas. In addition to this concern, rapidly growing populations, rapid economic growth and rise in community living standards have accelerated the generation rate of Municipal Solid Waste (MSW)...
Development of Hybrid Power System (HPS) is promoted and researchers are motivated to find new alternatives to increase the share of regenerative energy in the energy market all over the world. This is due to the fact that the world is well aware about fast depleting energy resources on one side and ever increasing demand for energy on the other side. HPS is a energy system with combination of different...
Protection of Class 1E bus is fundamental for safe operation of a nuclear power plant. Protection of this bus from under-voltage conditions is done by using a special two level or multi-level protection scheme. In this scheme, if the utility generator power is lost, power to Class 1E bus is supplied from the back up offsite power source. In case the offsite power is also unavailable due to any fault,...
This paper gives an in-depth review of some of the commonly used power management strategies for inverter interfaced solar PV microgrids. Solar PV microgrids tend to produce unstable power due to the variation of solar irradiance. This means there is always a power difference between the generation and the load. This difference would have a negative impact on the power quality if it is not managed...
The performance of concentrating solar thermal power (CSTP) plants is limited by the availability of the sun and other parameters such as land and water. One probable solution of viable operation of CSTP plants in Kenya is the hybridization of the CSTP plants with biogas backup systems to improve their performance. Biogas can be generated using dairy manure and the same can be used for hybridization...
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