Browsing by Author "Gunawardana, M"

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Analysis of the technical and economical aspects of contingency power and spinning reserves
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05-31) Weeraman, MS; Ambadeniya, ARAS; Senarath, DS; Gunawardana, M
Contingency power and spinning reserves are critical components of power systems worldwide, providing a vital role in maintaining system reliability and stability. In this paper, we analyze the technical and economic aspects of contingency power and spinning reserves, with a specific focus on Sri Lanka. We examine the current state of contingency power and spinning reserves in Sri Lanka and discuss anticipated structural reforms. Our analysis suggests that there is a significant potential for improving the technical and economic aspects of contingency power and spinning reserves in Sri Lanka. We propose a set of recommendations for policymakers to promote these improvements
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Analyzing the optimum contact angles of water droplets to mitigate the e-field stress on polymer insulator
(IEEE, 2022-07) Antony, AD; Arachchi, BATNKB; Gunasinghe, JB; Gunawardana, M; Samarasinghe, R; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
The water droplets present in the insulator surfaces cause variation in the e-field along the insulator surface. Variation in the e-field can lead to flashover and accelerate the ageing of the insulator and ultimately will end up in the breakdown of the insulator. The contact angle of water droplets is also a factor that determines the e-field variation. In this study, the effect of the contact angle of water droplets is analyzed using a simulation approach for different cases considering both pure and contaminated outdoor polymer insulators. The results show that the optimum range of contact angles of water droplets can be concluded as 70 to 120 degrees for a pure insulator, while the optimum range for a polluted insulator can be given as 70 to 100 degrees.
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Challenges and opportunities for introducing end to end electricity market in Sri Lanka: lessons from international case studies.
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05-31) Witharama, M; Senarathna, N; Somathilaka, S; Wijayapala, A; Gunawardana, M
This paper analyzes the challenges and opportunities for introducing an end-to-end electricity market in Sri Lanka, drawing lessons from international case studies. The Sri Lankan electricity sector faces several issues, including a state-controlled utility that is not financially efficient, hesitant to innovate and failure to stick with a fixed policy. The paper reviews literature on electricity market liberalization and analyzes case studies from Denmark, Australia, Pakistan, Japan,California and other countries to identify the requirements, benefits, and drawbacks of an end-to-end electricity market. The analysis includes a SWOT analysis of the Sri Lankan power sector, specific challenges that may arise in the Sri Lankan context, and suggestions to overcome them. The paper also discusses the impacts of an electricity market on different stakeholder groups, including consumers, producers, employees, and policymakers. The conclusion highlights the main findings and arguments, suggestions for policymakers and other stakeholders, and key lessons that can be learned from other countries experiences.
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Economical sustainability of electrical sector reforms in Sri Lanka: a review based on historical trajectories
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05) Jayawardana, GMBS; Gunawardana, M
Since its inception, Ceylon Electricity Board (CEB) has undergone several structural reforms to ensure the delivery efficient, coordinated and economical system of electricity supply. It has launched various initiatives, also, to fulfill those objectives. However, the financial adversities that CEB currently experiences question the success in achieving the said objectives. This paper attempted to address this gap between the original objectives and the performance strategies to achieve those objectives. The financial indicators as depicted in CEB publications were studied in a cohesive manner, in order to ascertain the possible reasons for such gap. The importance of identifying the behavior of different customer categories, especially the domestic consumer category, was noted. The heavily subsidized pricing structure, primarily aiming for social justice and welfare, should not serve its purpose. More scrutiny on the composition and response to reforms by the domestic consumer category is recommended, with provision for further studies in this arena.
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The Impacts of Deregulation of the Electricity Markets: A Comparative Study of International and Local Case Studies
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05-31) De Silva, RS; Weerasekara, H; Dias, MSV; Siyambalapitiya, T; Gunawardana, M
The Energy sector plays a crucial role in promoting economic development and sustainability, and energy reforms are vital for achieving a sustainable economic growth. Within the energy sector, the electricity sector holds significant importance, and reforms in this sector can have considerable impacts on the broader economy of a country. This research paper aims to evaluate the impact of energy reforms on the electricity sector, specifically focusing on policies that promote competition, innovation, and technological advancements. Through a comparative analysis of international and local case studies from the USA, Ethiopia, Nigeria, India, Singapore, and Sri Lanka, this paper assesses the micro and macroeconomic effects of energy reforms on power pricing, power markets, electricity accessibility, innovation, and competitiveness. The historical development of state-owned electricity monopolies and their impact on competition, innovation, technological advancements, pricing, and service quality in the electricity sector is also examined. Furthermore, the study analyzes the role of government oversight and regulations in managing state-owned monopolies to ensure fair market practices. This research paper contributes to a more nuanced understanding of the complex relationship between state ownership and market competition in the energy sector. The findings of this study can inform policymakers and stakeholders in Sri Lanka and other developing countries on the potential benefits and drawbacks of expanding state-owned electricity monopolies in the context of ongoing energy sector reforms. Overall, this study provides insights for designing and implementing effective energy policies that promote sustainable economic growth and development.
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Influence of grain distribution on orientation of saw cuts: Reference to heritage structures
(Elsevier, 2019) Mendis, MS; Halwatura, RU; Somadeva, DRK; Jayasinghe, RA; Gunawardana, M
Longitudinal arrangement of wood fibers are known as timber grains. It is one of the most important physical aspects of timber in applications. The properties differ along the grain and against the grain. Straight grains run parallel to the longitudinal axis of the wood. Meanwhile the cross grain deviates from the longitudinal axis as spiral and diagonal grains. This orientation has a high influence on the timber and affects physical properties during application. In order to study this, a detailed analysis was performed on Ambalam structures, a cherished heritage structure originated from the vernacular architecture in Sri Lanka. These structures are existing living proofs of vibrant construction materials with an exposed environment for more than 50 years. Badulla Ambalama,Padivitiya Ambalama, Panavitiya Ambalama, Karagahagedra Ambalama, Giruwa Ambalama and Rukula Ambalama were selected as case studies. The growth ring distribution of the exposed surfaces of the structural components were mapped using AutoCAD software. The results of overlapping and mapping the growth ring distribution of the specific timber helps to generate clues on size of the tree and sawing pattern of the wood log. The generated growth ring map revealed the sensitivity and the adequate knowledge in material manipulation utilized for specific structural components with respect to the load distribution. The Ambalam heritage structures have enlighten timber as an acceptable construction material with a respectable service life for tropical countries.
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International geopolitical relations on Sri Lanka’s power and energy sector: opportunities and challenges for a sustainable transition
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05) De Silva, RS; Pathirage, PAI; Thiranga, HGI; Fernando, ISM; Gunawardana, M
The energy crisis in Sri Lanka presents significant challenges for the country’s transition towards sustainable energy, given the outdated energy grid, lack of infrastructure, and heavy reliance on fossil fuels. The paper examines the short and long-term plans for generation expansion, as well as the new reforms set to be implemented in 2023. It analyzes the geopolitical relations between Sri Lanka and major international players in the energy sector, such as Japan, China, and India, and their respective energy sector reforms, including China’s Belt and Road Initiative and India’s Bay of Bengal Initiative. Through this analysis, the paper highlights the opportunities and challenges that exist for Sri Lanka in achieving a sustainable energy transition. It emphasizes the importance of leveraging geopolitical relations to shape the energy sector of a country and achieve sustainable energy goals. To this end, the paper provides recommendations, such as seeking partnerships and investments in renewable energy sources, promoting energy efficiency measures, and fostering international collaborations in research and development. This study provides valuable insights into the challenges and opportunities that exist for Sri Lanka in achieving a sustainable energy transition. It highlights the importance of taking a comprehensive approach that considers geopolitical relations and collaboration with international players to achieve sustainable energy goals.
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Management of municipal solid waste open dumps immediately after the collapse: An integrated approach from Meethotamulla open dump, Sri Lanka
(Elsevier, 2019) Jayaweera, M; Gunawardana, B; Gunawardana, M; Karunawardena, A; Dias, V; Premasiri, S; Dissanayake, J; Manatunge, J; Wijeratne, N; Karunarathne, D; Thilakasiri, S
Meethotamulla open dump (MOD) of Sri Lanka that has received about 290,000 metric tons of mixed MSW annually collapsed on 14th April 2017 with massive devastation. An integrated approach was attempted to control further collapse with the deployment of drone-assisted and stand-alone instrumentation. The collapsed dump was analyzed for attributes, including contours, heights, wetness, temperature levels, tension cracks, landfill gases, fire, explosion, and asphyxiation hazards with 24-h surveillance after one day of the collapse. The mode of MOD failure was implicated to be deep-seated (rotational) slope failure. A short-term plan, consisting of 12 activities was prepared and successfully implemented. The activities of the short-term plan were carried out at the dumpsite until the water level fluctuations <5 cm, inundation of the toe area receded completely, the horizontal displacement of surface markers <20 mm, lower explosive levels of CH4 and CO less than 5 and 12%, respectively, O2 level improved up to 21%, and temperature variation of the collapsed face <2 C. The short-term plan was halted when the factor of safety for slope failure of the critical face improved from 0.807 to 1.286 ensuring no signs of a subsequent collapse of the MOD. An early warning system was established in the case of an imminent collapse. This integrated approach, to our knowledge, is the first study instituted, and this holistic management effort could be easily replicated to avoid disasters from slope failures of landfills or open dumps that may occur elsewhere.
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National Symposium on Power Sector Reforms in Sri Lanka
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05) Gunawardana, M
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Neural network based model for estimating the resistance of outdoor distribution substation grounding
(Engineering Research Unit, 2023-12) Madhushan, PN; Pabasara, WMN; Shihab, M; Gunawardana, M
Grounding is one of the most important parts of an electrical system. Earthing systems are done to protect the power system and the personnel from the danger of electrical shocks. Ceylon Electricity Board (CEB) uses a special structure for transformer earthing arrangement. The used structure is copper bonded earth rod with a concrete filled steel cage. Due to the complexity of the structure and the nonlinear variations in soil parameters, it is challenging to determine resistance before implementing the structure. We can use an analytical formula for structures to find the resistance. [4] But for complex structure, as we use here, it is challenging to produce an analytical formula. The other solution is to use a Finite Element Method(FEM) to solve the problem.[2] But is also a time-consuming task.[1] So, we propose a combination of FEM and a neural network-based solution for this task.[1]. We propose to generate a data set using FEM and implement it in a neural network.
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Optimization of the potential benefits and options to overcome the challenges of restructuring the power sector.
(Electrical Engineering Society (EESoc) of the University of Moratuwa, 2023-05-31) Bamunusinghe, D; Gunawardana, M
The need for energy and power is anticipated to increase as the economies and populations of several developing nations in Asia and the Pacific continue to expand. Sri Lanka is likewise preparing to restructure the power industry. To support equitable and environmentally sustainable economic development, it is crucial not only to increase energy accessibility and supply electricity to everyone but also to improve the efficiency and responsiveness of their power sectors. The transition to a reformed power sector has the potential to generate significant benefits, including increased efficiency, reliability, and sustainability. However, this transition also presents a range of challenges, including regulatory hurdles, political resistance, and the need for substantial investment. It is vital to adopt a holistic and strategic strategy that takes into account all of the available options in order to maximize the potential advantages of power sector reform and get over these obstacles. This paper reviews the necessity of the reformation, the method of restructuring the power sector reform, benefits and identifies the key challenges facing this transition and explores the various strategies and options that can be employed to address these challenges. The paper concludes with recommendations for policymakers, regulators, and stakeholders on how to navigate the complexities of power sector reform and ensure that this transition delivers maximum benefits for all.
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Optimizing Marx Impulse Generator Settings for Lightning Impulse Testing of Transformers: An Automated Approach for Enhanced Efficiency and Accuracy
(IEEE, 2023-12-09) De Silva, RS; Vinusan, U; Aldeniya, SK; Samarasinghe, R; Gunawardana, M; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
The insulation strength of electrical equipment is required to be accurately tested to prevent insulation failures caused by abrupt overvoltages due to lightning strikes on power systems. In conventional methods, Marx impulse generators are used to produce impulse waveforms for testing. However, these methods often involve time consuming trial and error procedures and run the risk of damaging transformers during tests. This study proposes an algorithmic method for selecting resistor values in Marx generators to generate lightning impulse test waveforms. The proposed method establishes a circuit model based on the transformer’s frequency response and uses an optimization algorithm that combines a genetic algorithm with simulations of electromagnetic transients. The primary objective of the optimization process is to minimize the difference between the desired and simulated waveforms while obtaining optimum resistor block values. The proposed optimization-enabled method not only enhances accuracy in testing procedures but also reduces testing time and improves protection for test transformers. Consequently, these findings hold practical implications for electrical equipment manufacturers, test engineers, and researchers involved in insulation impulse testing, thereby promoting more reliable and effective testing procedures in the industry.
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Optimizing transformer fault detection: an investigation into current signal feature extraction
(Engineering Research Unit, 2023-12) Rathnasiri, KAKS; Dilsara, RPS; Siriwardhana, GCL; Gunawardana, M
Identifying faults is a crucial element in the realm of preventive maintenance and the condition monitoring of transformers. For fault detection of transformers many different conventional or advanced techniques such as short circuit impedance measurement, vibration and sound analysis, frequency response analysis (FRA), dissolved gas analysis and machine learning or deep learning have been used. Offline methods of fault detection are being experimented since faults can be detected at the earliest stages, the detection process does not disrupt power supply. By using feature extraction of the fault current waveform, the performance of the fault detection algorithm can be improved, and the accuracy of fault discrimination can be increased. The purpose of this study is to evaluate the use of feature extraction of current in fault transformers using wavelet transform in order to enhance the effectiveness of the fault detection in transformers. A simulated PSCAD model derived using lumped parameter network in [1] is used for the generation of different types of faults and obtaining their fault current waveforms for feature extraction