3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item House hold and collective responses to the absence of electricity supply in informal settlements in Johannesburg: a case study of Msawawa and Kya Sands(2018) Nxumalo, Feza HughThe South African Constitution gives every citizen a right to basic services, and this exclude electrification of every households. It covers basic human rights, and articulates them as Water, and Sanitation. The Department of Energy recognises electrification as basic right through electrification categories provided for informal settlements dwellers. However, many households in informal settlements live without electricity. This research is a case study of Kya Sands and Msawawa informal settlements, two informal settlements on the north western outskirts of Johannesburg that are not connected to formal electricity supply. It explores how their communities respond to the absence of electricity. The study took a qualitative approach based on interviews with residents, business owners and leaders of Msawawa and Kya Sands informal settlements. The finding is that household responses differ across the two informal settlements, in part depending on the strategy adopted by the informal settlement community and the leadership, and in part determined by the sources of energy or fuel in the area. This research reveals a variety of energy sources, and questions the common perception that all informal settlement dwellers have informal electricity connections.Item Comparative study of a time diversity scheme applied to G3 systems for narrowband power-line communications(2016) Rivard, Yves-FrançoisPower-line communications can be used for the transfer of data across electrical net- works in applications such as automatic meter reading in smart grid technology. As the power-line channel is harsh and plagued with non-Gaussian noise, robust forward error correction schemes are required. This research is a comparative study where a Luby transform code is concatenated with power-line communication systems provided by an up-to-date standard published by electricit e R eseau Distribution France named G3 PLC. Both decoding using Gaussian elimination and belief propagation are imple- mented to investigate and characterise their behaviour through computer simulations in MATLAB. Results show that a bit error rate performance improvement is achiev- able under non worst-case channel conditions using a Gaussian elimination decoder. An adaptive system is thus recommended which decodes using Gaussian elimination and which has the appropriate data rate. The added complexity can be well tolerated especially on the receiver side in automatic meter reading systems due to the network structure being built around a centralised agent which possesses more resources.Item Investigation into the steady-state load sharing of weak sources in a low voltage three-phase islanded microgrid(2016) Wu, Meng-Chun MereldaThis research investigates the power sharing between distributed energy resources with voltage and frequency droop control. A case study based on voltage sources in an islanded microgrid is set up in the laboratory, referred to as: The Example Microgrid. The Example Microgrid consists of two synchronous generators, active and reactive power loads. A simulation model is constructed based on the laboratory set-up, where componentwise and system-wise testing are completed. The simulation results are validated with the experimental set-up, and it is concluded that the model accurately represents the physical system under steady-state conditions. Further simulation studies on conventional droop controllers are conducted based on the Example Microgrid model. The results indicate that the use of conventional droop control is inappropriate for small, low-voltage islanded microgrids. As a possible application of this work, three variations of adapted droop controllers are simulated and their performance evaluated. It is found that with the adapted droop controllers, the power sharing error can be minimised