Browsing by Author "Dhanapala, W.C.H."

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    An Analysis of Medium Voltage Feeder Tripping in Ceylon Electricity Board Distribution Network – A Case Study of Western Province South 1 Network
    (Uva Wellassa University of Sri Lanka, 2021) Chathuranga, B.L.P.G.; Dhanapala, W.C.H.; Wickramasinghe, W.M.S.M.
    Providing a reliable power supply with minimum breakdowns is one of the main objectives of any electricity supply company. Frequent breakdowns in the power system occur due to various faults. To improve network reliability, it is more essential to have a proper analysis of these faults and incorporate them into the network development plans. The main objective of this research is to do an analysis of the feeder tripping details in a selected area of the Ceylon Electricity Board Medium Voltage distribution network. The area of Ratmalana, Kalutara, Mathugama, and Dehiwala which operates under Western Province South 1, Ceylon Electricity Board were considered for the present study and feeder tripping data were collected from relevant grid substations for the year 2019. First, an analysis was done to identify the feeder lines with frequent failures. The Auto type feeder tripping details of the selected feeders were then further analysed and it was observed 75.02%, 14.48% and 6.15% of faults were due to Earth Faults, Over-Current and simultaneous occurrence of Earth Faults and Over-Current respectively. The rest were due to the Under Frequency relay operations and 132 kV incoming failures. Auto type feeder tripping occurs repetitively in the network and minimizing them leads to building up a healthy network. These repetitive failures can be minimized by addressing solutions for individual feeder lines, where frequent failures occur. Hence a comprehensive analysis to identify the reasons for auto type feeder trippings is extremely important. Utilities can incorporate these research findings in their network development plans. They will consequently be able to eliminate many repetitive breakdowns on the Medium Voltage Network, and thereby improve the network quality while maintaining reliability indices at an optimal level and increase their financial revenue. Keywords: Auto type Feeder tripping; Ceylon Electricity Board; Earth Faults; Medium voltage distribution network; Over-Current Faults
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    Technical and Economic Feasibility of Recycling Aluminum Scrap to Aluminum Re- Draw Rod
    (Uva Wellassa University of Sri Lanka, 2021) Dhanapala, W.C.H.
    Maintaining the bear low voltage line is a major difficulty that Ceylon Electricity Board faces today since it is very sensitive to the natural and other impacts such as wayleaves, animal collisions and electricity thefts. At present, Aerial Bundled Conductors are used for replacing existing low voltage bear lines under maintenance/rehabilitation work and for newly constructed schemes or new extensions. Aerial Bundle Conductors provide multiple benefits to the electricity distribution network by increasing the network effectiveness, reducing the distribution network failures/faults and losses, minimizing clearing of vegetation which protects environment especially in urban areas, protecting the distribution network from theft and illegal tapping. When the low voltage power lines of bear Aluminum conductors are converted to Aerial Bundle Conductors, the Aluminum conductors are removed as scrap material and nearly 1000 MTon Aluminum scraps are being sold per year at a predetermined price without using it for value-addition purposes. This project involved the study and investigation of the technical and economic feasibility of recycling Aluminum scrap into Aluminum Re-Draw rod to manufacture low voltage Aerial Bundle Conductors from the recycled Aluminum scrap. Testing and detailed analysis were done on chemical composition, electrical properties, mechanical properties and dimensional tolerance to the find technical feasibility of the scrap Aluminum recycling process. Accordingly, with respect to all testing and analysis, fabricating Aluminum Re-Draw Rod from scrap Aluminum is technically feasible. Further, a pricing formula was generated and the total price was calculated for the Aluminum Re-Draw rod fabricated from recycled Aluminum scrap by studying, witnessing, measuring and analyzing every sub-process of the Aluminum recycling process namely Aluminum cleaning, Aluminum bailing, scrap ingot making and Re-Draw Rod making. From this recycling process of Ceylon Electricity Board, the country can save about US $ 2.3 million (Rs 412 million) foreign exchange per year by converting 1000 MT of scrap Aluminum to Re-Draw Rods every year. According to the results, the economic benefit of the process of recycling will be more than 50%. Hence this process of recycling Scrap Aluminum to Aluminum Re-Draw rod is technically and economically feasible. Keywords: Ceylon Electricity Board; Aerial Bundled Conductors; Aluminum; Recycling; Feasibility