Evaluation of key factors influencing a South African based electrical utility to utilise smart grid technologies for power quality management

Abstract

With the ever-growing global drive to reduce carbon emission compelling the need to diversify Energy generation options, solar and wind renewable energy sources are the popular choices in South Africa. Since photo-voltaic sources are variable and injected by means of a solid-state interface, special consideration is needed, to control the frequency and have sufficient energy available during all load conditions. In addition, maintaining adequate levels of reliability and voltage quality to end users necessitates more sophisticated and intelligent network capabilities. It is within this context that this dissertation seeks to examine the influence of smart grid on electrical network and explore its application by a South African power utility to facilitate the monitoring and improved management of power quality on distribution networks. Internationally, research trends indicate that the implementation of the smart grid on electricity network can and does lead to increased network reliability, energy efficiency, and improved power quality. However, this theory has not been fully tested in South Africa and until recently, South Africa has mostly trailed the world in the adoption of smart grid technology. This lack of empirical evidence led to the primary research question: Does the use of smart grid technology on distribution networks provide opportunities to improve the management of power quality for a South African-based power utility? Secondary research questions were formulated to adequately answer the stated primary research question and to achieve this, based on the problem statement, it was necessary to: • Develop measures for the concepts power quality management and smart grid technologies; •Determine the scope of the power quality management program in a South African-based power utility; • Determine the extent to which South African-based power utilities can utilize smart grid technologies for their network operations; • Identify themes, links, and patterns in the description of industry participants regarding their experiences and industry sensitivity to power quality issues and their views on smart grid technologies; and • Formulate factors that influence a South African-based power utility's decision to use smart grid technologies for power quality management. Based on the philosophy of pragmatism as the research paradigm, an empirical investigation comprised of both quantitative and qualitative studies were undertaken as part of mixed-methods research design. In the quantitative phase, a comprehensive literature study is used to describe the concepts of power quality management and smart grid technologies and thereafter a non-experimental, cross-sectional online mail survey is carried out using a structured questionnaire with the participation of South African power utilities who have a program to manage power quality of their electrical networks. A proposed model and hypotheses are verified, using a single-stage descriptive analysis by cross-referencing with findings made from the literature study. The verification of the model supports the proposed hypothesis that smart grid technologies can be used to enhance the management of power quality on distribution networks for a South African-based power utility. To improve confidence of the findings and to ensure that the problem statement was appropriately addressed and to enable data triangulation to take place, it was necessary to develop a related instrument that was content and context specific. To achieve this, a descriptive and explorative qualitative inquiry is undertaken by means of semi-structured interviews, to develop an in-depth description of seven individuals representing large industrial customers of power utilities in South Africa. Their reactions to interview questions were used to gauge the sensitivity of industry role-players to power quality issues and their views on smart grid technologies. Once the quantitative and qualitative data was interpreted, a SWOT analysis was performed on the research findings, to formulate suitable factors toward the implementation of smart grid technologies by a South African-based power utility. The main conclusion drawn in the research is that if a South African utility were to implement smart grid technologies, it can enable them to improve the management of power quality. Other conclusions drawn include that larger utilities like Eskom and metropolitan utilities are in a better position with adequate resources and power quality expertise to effectively enhance the management of power quality through the use of smart grid technologies. Another conclusion was that regardless of the type of industry, voltage dip events experienced by the industries can interrupt productions and loss of income. It also emerged that power quality events may lead to severe complications for various industries, which power utilities may not be aware of. For instance: Chemical and Mining industries are susceptible to explosions and fires if an unplanned prolonged supply interruption occurs, posing a safety risk to workers. Likewise, untreated and unsafe drinking water may flow into the pipelines if a power quality event were to cause power interruptions to the Water Pumping and Purification industries. Moreover, the following factors that influence a South African utility's decision to explore the use of smart grid technologies on distribution networks are identified: • Power utilities can collaborate with research institutions and non-governmental institutions to develop smart grid pilot systems; • Development of a microgrid system at a smaller scale is possible through government support; • Utilities can be enabled to keep an efficient, automatic modernized electricity network; • Utilities have an opportunity to acquire the intelligence to facilitate the integration of the technologies of renewable energy generation (solar and wind) into the distribution network, and maintain efficient voltage control capabilities; • The benefit of advanced distribution automation can enable a South African utility to improve the monitoring of power quality and reliability of supply to the benefit of customers by proactively rerouting supply networks during times of power outages or severe voltage fluctuations; and • Utilities can achieve a dynamic real-time decision and management of network parameters, and identification of system disturbances can also be enhanced through the smart grid on a SCADA system. Finally, it is concluded that a need for synchronized measurement of power quality data in a wide area network exists for a South African utility, to allow comparison of PQ data measured at different network locations as though the measurement were all made by a single instrument. This phenomenon can be made possible by synchronization of the phasor measurement unit using a common time distribution such as the GPS. It is therefore recommended for power utilities in South Africa to consider the use of PQ instruments with precise time protocols that can allow synchronized data measurement such as phase angle variations across a wide area, which would be useful for comparison of PQ disturbances on smart grid implementation for distribution networks.