Browsing by Author "Silva, Izael P. Da"

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    A Heuristic Model for Planning of Single Wire Earth Return Power Distribution Systems
    (Bakkabulindi, G., Hesamzadeh, M. R., Amelin, M., Da Silva, I. P., & Lugujjo, E. (2011)., 2011) Bakkabulindi, Geofrey; Hesamzadeh2, Mohammad R.; Amelin, Mikael; Silva, Izael P. Da; Lugujjo, Eriabu
    The planning of distribution networks with earth return is highly dependent on the ground’s electrical properties. This study incorporates a load flow algorithm for Single Wire Earth Return (SWER) networks into the planning of such systems. The earth’s variable conductive properties are modelled into the load flow algorithm and the model considers load growth over different time periods. It includes optimal conductor selection for the SWER system and can also be used to forecast when an initially selected conductor will need to be upgraded. The planning procedure is based on indices derived through an iterative heuristic process that aims to minimise losses and investment costs subject to load flow constraints. A case study in Uganda is used to test the model’s practical application.
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    Rural Electrification Practicalities of Using Single Wire Earth Return as a Low-Cost Method for Grid Extension: The Case of Ntenjeru, Uganda
    (Bakkabulindi, G., Da Silva, I. P., & Lugujjo, E. (2009, August), 2009) Bakkabulindi, Geofrey; Silva, Izael P. Da; Lugujjo, Eriabu; Söder, Lennart; Amelin, Mikael
    The fact that the vast majority of Uganda’s rural areas remain un-electrified makes it imperative that low cost distribution technologies be implemented in order to provide affordable electricity to rural households. Such low cost technologies include the Shield Wire System (SWS), Single Wire Earth Return (SWER) and appropriate engineering techniques. The SWER technology is presented in this paper as well as the implications of its proposed implementation for electrification of the village of Ntenjeru in Uganda. While SWER can reduce the costs of electrification by more than a third compared to conventional high tension transmission lines, there are stringent grounding and safety issues as well as load capacity constraints involved. Furthermore, with the earth used as a current return path, soil resistivity analysis is important in these systems. Since soil resistivity can vary sharply over varying terrain and in different weather conditions, robust SWER systems have to be carefully designed. An analysis of the financial and electrical load implications of this technology in Uganda’s local conditions will be presented and its viability as a sustainable method for electric energy distribution in the chosen case study area.