An Investigation Into The Influence Of Ageing Components On Medium Voltage Network Configurations In Semi-Urban Areas

Abstract

Access to electricity for all South Africans is a goal that is still achievable. Access to electricity is not a luxury, but a need. Electricity improves all individuals’ lives, including those who live in semi-urban areas. Most of the medium voltage electrical networks that supply semi-urban areas are more than 30 years old; some are beyond repair. The existing electrical network configurations can cause accelerated ageing of electrical components, which can have a negative impact on performance, quality of supply and the public. The three semi-urban areas selected for the study were located in different parts of Northern Cape. Visual inspection, components failure rate and voltage simulations were used during the investigation to shed light on the details of the selected networks and their ageing characteristics as well as how ageing components or infrastructure affect the performance of the network, the safety of personnel and equipment, and quality of supply. Components on the electrical networks selected for the research have different deterioration characteristics in accordance with their environment and design of electrical network configuration. Ageing of electrical components on the network is mainly due to the materials used on the components, which deteriorate naturally after a certain period of service. However, some of the materials age because they have been operated beyond their design specifications. In relation to ageing, the most affected components are jumpers, pole-mounted transformers and wooden poles. Component failures lead to poor performance of the network as well as an unsafe and unreliable network. Northern Cape has one of the largest landscapes in South Africa, which makes the distribution networks much longer than they usually are. Thus, more time is needed to inspect them than any other networks in South Africa. Ageing of components on the electrical network can result in capital loss, loss of life and high supply interruptions, which result in loss of revenue for the power utility. The results of this investigation show that safe, reliable and correctly designed or utilized electrical networks in semi-urban areas can improve the performance and quality of supply as well as reduce the maintenance costs of the network. The study shows that most of the component failures were more common in certain areas of the selected networks. Premature failures and ageing of components on MV network was one of the main causes of deteriorating performance on MV networks in semi-urban areas. In the field of electrical engineering, the focus is more on major components on the electrical network including power transformers, reactors and generally high voltage components because they are more expensive. Medium voltage components generally cost less than high voltage components; consequently, the cost of their maintenance is much lower, which is a gap that can be explored in future research.