Senate Research Committee – Reports

Permanent URI for this collectionhttp://192.248.9.226/handle/123/8849

Browse

Recent Submissions

Now showing 1 - 20 of 236
  • item: SRC-Report
    An Improved Markov maintenance model for power system equipment [abstract]
    (2019) Abeygunawardane, SK
    Distribution utilities compute several reliability indices to assess the reliability performance of power systems. In reliability-based planning, these indices are computed using reliability planning models. Such models require failure rates and mean downtimes of distribution feeders as inputs. At present, there is a lack of models for calculating operational mean downtimes of distribution feeders. This paper proposes a Markov model which represents failures in a feeder and operations circumstances in fault recovery. This proposed model can efficiently calculate the operational mean downtime of a feeder, using analytical equations. An algorithm and a graphical user interface are also developed based on the proposed model, in order to integrate the proposed model with software tools. Two case studies are conducted on two selected feeders, using actual data obtained from failure and repair histories and experts’ opinion. Results of case studies show the applicability of our proposed Markov model-based algorithm to calculate mean downtimes of distribution feeders. The Markov model is validated by comparing results provided by the proposed algorithm with the results obtained using Monte Carlo simulation. The proposed Markov model-based algorithm would be very useful for utilities to calculate operational mean downtimes required for reliability-based planning models.
  • item: SRC-Report
    The enKindler space : a conceptual model to elevate creativity using multi-sensory stimuli [abstract]
    (2020) Hettiarahchi, AA; Wadinambi Arachchi, WADS
    This paper proposes a conceptual model that can enable design students to elevate their reativity levels. When considering essential intrapersonal skills in becoming an eminent designer, Self-actualization is a critical trait. This ability will lead individuals to reach their zenith of creativity as it breaks their egoistic nature. Further, mindfulness is apparent as a path to achieving self-actualization. Therefore, this study attempted to explore ways to instill self-actualization via mindfulness practices in students in design classrooms with an interactive approach. In doing so, we conducted a comprehensive literature review on creativity and creativity enhancement methods. In this attempt, we found the unique practice of using multisensory stimuli, which is contrasting with conventional methods of boosting creativity. Yet, this mechanism has rarely been explored over recent years. When dived in-depth, we found that the application of Multisensory stimuli to enhance creativity has a long history and is taught in the concept of Chakra in Vedic teachings of India. Therefore, in this paper, we will explain the formation of the conceptual model "enKindler Space,” which was composed by drawing inspiration from the concept of Chakras and applying theories of creating interactive, multisensory experiences.
  • item: SRC-Report
    An Examination of alternative revenue sources in urban local governments, Sri Lanka
    (2015) Susantha, AL; Bandusena, P
    Local governments are the main grassroots unit close to the local community as it provide comfort, convenience, democratic values and accelerate economic development. Though it has the power to maintain its budget by creating new sources to perform as an independent body under the decentralized power vested by the central government, in Sri Lanka, most Local Authorities (LAs) are running on a deficit budget. Therefore, local governments are in a dilemma to provide essential services to the local community which leads to community dissatisfaction and ultimately there is a discourse of returning the power to the central government. However, due to rapid urbanization and wicked urban problems top-down governance is complex and revisiting the local opportunities and challenges have for local governance is timely. In this context, this research attempts to introduce new revenue sources for enhancing local authority revenue while examining the opportunities and challenges. A comprehensive literature review was done to identify alternative revenue sources practiced in other countries. Interviews is the main method administered in selected urban local authorities (ULA) in the Western Province. Key participants are officers of the local authorities and professionals who are working in the local governance system. The collected materials were transcribed and analyzed using a content analysis inspired by grounded theory. According to the findings, development levies, betterment fees, profit-oriented events, and income-generating projects/businesses are the potential alternative sources of revenue that can be considered in the Sri Lankan context. Further, procedural changes and capacity building enhancement for (Internal) Urban Local Authorities are essential to identify potential stakeholders and standardize the services provided.
  • item: SRC-Report
    Energy efficiency improvement in cloud radio access networks (CRANs) using device centric caching policies
    (2018) Samarasinghe, T; Hemachandra, K; Atapattu, S; Nuradha, T; Ranawaka, I
    As the demand for wireless services is projected to double every year, wireless system designers are facing a major crisis to cater to this demand with the conventional cellular network architecture due to the scarcity of spectrum resources and high cost of energy consumption. Therefore, major architectural changes such as cloud radio access networks (CRANs) and device-to-device (D2D) communications have been proposed as potential solutions. The proposed research project is mainly focuses on improving the performance of the CRAN architecture. Firstly, we propose a spectrum selection scheme and a transmit power minimization scheme for a D2D network cross-laid with a CRAN. The D2D communications are allowed as an overlay to the CRAN as well as in the unlicensed industrial, scientific and medical radio (ISM) band. A link distance-based scheme is proposed and closed-form approximations are derived for the link distance thresholds to select the operating band of the D2D users. Furthermore, analytical expressions are derived to calculate the minimum required transmit power to achieve a guaranteed level of quality of service in each operating band. Secondly, a novel content caching strategy is proposed for a cache enabled D2D network where the user devices are allowed to communicate using millimeter wave (mmWave) D2D links (> 6 GHz) as well as conventional sub 6 GHz cellular links. The proposed content placement strategy maximizes the successful content delivery probability of a line-of-sight D2D link. Furthermore, a heuristic algorithm is proposed for efficient content delivery. The overall scheme improves the successful traffic offloading gain of the network compared to conventional cache-hit maximizing content placement and delivery strategies. Significant energy efficiency improvements can also be achieved in ultra-dense networks. Finally, we consider the physical layer security of an untrusted unmanned aerial vehicle (UAV) based D2D network, operating in full-duplex mode. A source-based jamming scheme is exploited for secure communication without utilizing any external jammers. Firstly, the optimal power allocation between the confidential signal and the jamming signal is derived to maximize the secrecy rate of each link between the source and the destination. Then, the best UAV selection scheme is proposed to maximize the overall secrecy rate of the network. The corresponding secrecy outage probability and the average secrecy rate of the network are analyzed based on the proposed UAV selection and the optimal power allocation schemes. Asymptotic results are also obtained to derive the achievable diversity order.
  • item: SRC-Report
    A Tool for estimating remaining life of power transformers
    (2017) Samarasinghe, R; Lucas, R; Ediriweera, S; Jayarathna, P
    Part 1- Modelling the Lumped Parameter Network of a Power Transformer using Sweep Frequency Response Analysis Accurate modeling of power transformers is beneficial for fault diagnosis and the health condition assessment of the power transformers. This project proposed a novel approach of synthesizing the lumped parameter equivalent circuit of a power transformer using its frequency response by utilizing artificial neural networks and the genetic algorithms. A physically realizable transfer function derived using the sweep frequency response data of a power transformer is used to construct its lumped parameter equivalent circuit model. Then, the parameters of the model are estimated using an artificial neural network and the genetic algorithm. All parameters, objectives and constraints of the genetic algorithm and the artificial neural network are set appropriately to ensure accurate results within the shortest time span. The entire approach is validated by means of an error analysis. The proposed method is easy to implement and can be used effectively to improve the reliability of power system though accurate fault identification and health assessment of power transformers. In addition, by replacing general equivalent circuit with the proposed model, the accuracy of transient analysis results can be significantly enhanced as the high frequency behavior is simulated using lumped parameter network. Part 2 - Fractal Characteristics of Creeping Discharges Propagating on Solid/Liquid Dielectric Interfaces A solid/liquid dielectric interface is considered a weak point in a composite insulation system, as it facilitates creeping discharges on the interface. This project proposes the use of nano-dielectrics to minimize the effect of damages which occur due to creeping discharge activity on such interfaces. A point-plane electrode arrangement-based test apparatus, energized by a high voltage supply, is used for analyzing the propagation of creeping discharges over solid/liquid interfaces using visual observation. An algorithm is used to determine the fractal dimension of creeping discharges propagating over various solid/liquid insulating interfaces. The results show that the use of nanofillers can increase the dielectric breakdown strength of epoxy by 7%.
  • item: SRC-Report
    Design and development of a tactile feedback system, and its application to prosthetics and tele-operated robots
    (2017) Chathuranga, KVDS; Lalitharatne, SWHMTD
    After seeing and hearing (vision and audition), tactile sensing (feeling of touch) is the third most utilized sensation. We use our fingertips to examine properties of objects such as weight (heavy or light), shape (spherical/round or shapes with edges and corners etc.), and texture (smooth or rough). In many situations we can identify and discriminate objects by touch only. Furthermore, tactile sensing is needed for controlling the gripping force of objects and object manipulation tasks. An example would be holding an egg without dropping. We apply just enough grip force to hold the egg and careful not to crush the shell. This is possible due to the ability of the tactile sensors in the fingertips to detect micro slips occurring at the common surface of the object and the fingertips. The adjustment of its grip force is controlled by the detection of insipient slip. This tactile sensing capability is required for both tele-operated robot systems and artificial prosthetic hands that has actuated fingers for grasping and manipulation. However, limited research has been conducted to address these issues. Researchers have tried to copy the abilities of human fingertips to robots. However, only few research has emerged with usable technologies due to the complexity of the tactile system and its information processing. Therefore, this project is conducted mainly to develop a biomimetic tactile sensing system and its control strategy for the use in prosthetic hands and a tele operated robot systems. The project proposed a tactile sensing system and an accompanying haptic feedback systems developed using soft materials. The tactile sensors were made using magnets, hall sensors and soft overlays. The tactile arrays were used to measure tactile data while haptic feedback system made from magnets, voice coils and soft material overlays transmitted the tactile information back to the skin. The grant was successful to develop soft tactile sensor array and a soft haptic device. These devices were utilized in a prosthetic arm to transmit tactile data to the wearer of the prosthetic arm. This tactile data was used to manipulate an object from the prosthetic hand..
  • item: SRC-Report
    Deformation mechanisms of silicon electrodes in rechargeable Li-ion batteries
    (2019) Sitinamaluwa, HS
    Silicon has received a significant attention as a promising anode material for rechargeable Li-ion batteries owing to its high theoretical capacity (4200 mAhg-1) and relatively low operating voltage (0.4V vs Li/Li+). However, cycling performance of Si electrodes remains very limited due to large volume changes upon alloying and de-alloying with lithium, resulting in poor mechanical stability and early capacity fade. To address this issue, sound understanding of mechanical behavior of silicon electrodes during electrochemical lithium insertion is required. In this study, molecular dynamic simulation is employed to simulate the deformation behavior of lithiated amorphous silicon (a-Si) under nanoindentation at different stages of lithiation. The results are used to characterize the effect of Li concentration on hardness and modulus of the electrode, as well as the lithiation-induced plastic deformation. The effect of Li concentration on mechanical properties and deformation mechanisms are thoroughly explored during the nanoindentation process. The results indicate the transition of the properties of a-Si electrode with lithiation; from a hard, covalent solid into a soft, ductile alloy which can accommodate large plastic deformation. Obvious elastic and plastic deformations occur under the nanoindentation of a-Si and LixSi. Clearly different deformation mechanisms of Li-poor structures and Li-rich structures under indentation are revealed. Plastic deformation of a-Si is governed by the increasing fivefold coordinates of silicon network structure. In contrast, plastic flow of Li-rich structures is found to be governed by migration of shear transformation zones. Increased disorder of Li-Si alloys with electrochemical Li insertion might play a vital role on the formation of shear transformation zones in Li-rich LixSi alloys
  • item: SRC-Report
    Impact of entrepreneurial orientation and entrepreneurship education on entrepreneurial intention and internationalization of engineer-entrepreneur start-ups
    (2021) Mudalige, DM
    Despite favourable impressions of entrepreneurial orientation and entrepreneurship education on entrepreneurship behaviour from past research, the influence of entrepreneurial orientation and entrepreneurship education on achievement entrepreneurial goals of engineers in Sri Lanka remains understudied and uncertain in many circumstances. This necessitates a thorough examination of the mechanisms by which entrepreneurial orientation and education influences entrepreneurial intention. Further, as per international entrepreneurship theory, entrepreneurial intent leads to internationalization intent when facilitated by conducive environment factors. The objective of research is to investigate the influence of entrepreneurial orientation and entrepreneurship education on entrepreneurial intention and internationalization intent of engineer entrepreneurs in Sri Lanka. Three hypotheses related to above links were tested using a validated questionnaire through a survey of 92 engineer-entrepreneurs. The results show that there is a significant positive relationship between entrepreneurial orientation and entrepreneurship education on entrepreneurial intention and internationalization intent of engineer entrepreneurs in Sri Lanka. The variable entrepreneurial intention explained 40% variance of internationalization intention. This research gives valuable inputs and suggestions with respect to entrepreneurship education and promotion of entrepreneurship orientation of engineers in Sri Lanka for policy makers.
  • item: SRC-Report
    Development of pavement management system for low volume roads
    (2018) Pasindu, HR
    Low volume roads which are playing a pivotal role in community development, transport of people, goods, and services. Limited funding, inability to collect extensive data, subjective ad-hoc maintenance decision making has resulted in suboptimal maintenance level for these road networks. Therefore, there is a need to develop a cost-effective simplified approach for network-level decision-making to assist in pavement maintenance management. The research is focused on identifying a cost-effective method to collect the required data to assess the pavement condition. Also, it comprises by identifying the maintenance strategies and respective thresholds for low volume roads which can be used in the decision tree to support the decision-making process. Moreover, developing an analytical framework for optimize network level pavement condition, incorporating the decision tree to eliminate the limitations of subjective maintenance decision making is the main analysis approach in this study. Finally, to incorporate objective functions which cannot be accommodated in single objective analysis, a multi-objective optimization analysis scheme is developed. The applicability of smartphone-based roughness data was explored to assess the pavement condition by validating with the conventional class III roughness measurement equipment. It was found that the reliability of smartphone roughness was high with correlation of 0.84. In addition to that, roughness capability of forecast distress level, prediction of overall condition was evaluated. The multiple regression models shown that raveling, pothole, cracking, patching have a good relationship with roughness progression in wider roads while edge breaking, and edge gap have significant impact in narrow roads. In the analysis framework genetic algorithm-based optimization approach was found as the best evaluation tool compared with the engineer’s objective decision making and linear programming especially in limited budget conditions. Moreover, the use of socio-economic importance as a secondary objective was better option, which gives priority to roads having higher socio-economic importance.
  • item: SRC-Report
    Enhancing the electronic service quality of information systems : a study based on selected Universities in Sri Lanka on students’ perspectives [abstract]
    (2018) Gunawardhana, DNT
    Information Systems in the Universities provide an amazing service to make educational activities run smoothly. Student Information Systems, Learning Management Systems, and Document Management systems are getting priority among them. With the rapid increase in online services, the quality of electronic services is being further discussed. Enhancing the quality of electronic services is of paramount importance to provide a better service. The main objective of this research was to study how to enhance the electronic service quality of Information Systems in the Universities of Sri Lanka. It examined different dimensions and disciplines. The research was conducted using two selected universities in Sri Lanka. Mixed research methods were used. SPSS software and NVivo Software were used for data analysis. The factors significantly affecting the quality of electronic services in the information systems of selected universities were identified. They are Background Factors, Technological Factors, Cultural Factors and Other Factors. The importance of a Social Learning Management System (Social LMS) and a Research Management System was discovered in the improvement of electronic services.
  • item: SRC-Report
    Preservation of Kandyan traditional clothing (dress forms, draping methods and their usage in context) in the UNESCO world cultural heritage site Kandy and its vicinities in Sri Lanka
    (2018) Karunaratne, PVM; Ranathunga, GM; De Silva, SSV
    Historical notions of cultural value in the heritage sector have been determined by holders of curatorial expertise based at institutions with large collections of artifacts. However, the rise of new digital technologies has facilitated not only active two-way engagement with heritage, but also a broadening of what we mean by heritage and how it can be accessed, through the co-production of exhibitions, oral histories, and other forms of display and archive based on personal remembrance, recollection and interactivity. Since the late 1990s the potential of the digital world for generating new ways of engaging with heritage, broadly defined, has been a key focus of both academic work and cultural practice. At times, the emphasis has been on how the Internet can provide a 'shop window’ for the sector, and how this might be translated into physical visits to sites. Elsewhere, the literature explores how the digital sphere can be exploited to provide a dynam1c space for two-way engagement with heritage culture, aimed at providing a complementary experience to the physical visit through a range of phenomena (online communities,). The aim was to establish the potentiality of virtual new-media to digitally preserve the tangible traditional dress form after transferring in to new paradigm and create an avenue to preserve the vernacular with their socio-cultural context the intangible cultural heritage of Sri Lanka. How traditional dress form change to a contemporary form of dress is examine in the video production ..
  • item: SRC-Report
    Development of a model of cyber space for simulate cyber security level and data transmission latency of the modern power system
    (2019) Hemapala, KTMU; Priyadarshana, HVV
    The integration of DERs into the transmission and distribution grid introduces new consequence for distributed network operators (DNOs). Although distribution network was considered as a static system without major control operations or reconfiguration requirements. For a smart grid, distribution network can be considered as a dynamic system due to DERs. Power routing is an emerging concept. Its main purpose is to make the distribution network more flexible which will help to solve the technical issues related to DERs. With the introduction of DERs, DNOs have faced many challenges. Communication is one of major challenges in DNO Technology. Nowadays most of the communication architectures are based on the Internet that creates major security issues with the system. Cybersecurity Enabled Communication Architecture is the most important concept for Power Routing. The main objective of this research was achieving a Cyber-security Enabled Communication Architecture for Power Routing. This study has developed an IPSec tunnel for the cyber-security enabled communication. The method is simulated, and results are produced that shows the effectiveness of the developed communication method. The study shows that the developed cyber-security enabled communication architecture for power routing based on IPSec tunnel performs well to hide the related information in the Wide Area Network.
  • item: SRC-Report
    Structural behavior of the doubly curved shell structure using mud-concrete (MC)
    (2020) Jayasinghe, RR; Halwatura, RU; Nanayakkara, KIU; Arooz, R
    Mud-Concrete is a concrete material which uses soil as its primary binding material. Mud-concrete deviates from typical concrete mixture by replacing sand and granite coarse aggregates with a graded soil. When mud-concrete is used as a walling material, initial cost and operational cost is comparatively low compared with that of cement brick or burned bricks walls. The environmental impact of the mud concrete is significantly low compared with other building materials. This paper presents the possibility of developing a doubly curved earthen slab system using mud-concrete to achieve demands of economy, environment and aesthetics. The work presented in this paper is broadly aimed towards developing an earthen slab system for housing in Sri Lanka. The main objectives of this research are to; • Propose a feasible structural system for an earthen slab system • Develop a practical construction sequence for the proposed slab system • Evaluate economic and environmental viability of the proposed slab system To fulfil both environmental and economical demands in the construction industry; reducing the cost and labour expenses nearly 50% compared with that of traditional reinforced concrete slab systems. A I m x I m prototype mud-concrete slab was constructed to check the potential for modular construction with a square footprint. Poured mud-concrete shell of 50 mm thickness is the primary structural component, while a non-structural mud-concrete filling to a horizontal/eve/ 50 mm from apex was used to create a usable floor surface. Masonry mould method was used as the form work system for the construction considering its cost effectiveness and ease of construction.
  • item: SRC-Report
    Multi agent system based microgrids for distribution network
    (2018) Hemapala, KTMU; Wijayapala, WDAS; Perera, MK
    This research focuses on a novel approach which is multi-agent-based control systems for microgrids. A microgrid is important in integrating distributed generators and local loads. Unlike the conventional centralized control, multi-agent system provides a distributed control over the distribution network. A multi agent system comprises of multiple agents. These agents are hardware or software entities that can interact with each other in realizing the objectives of the microgrid. The main objective of this research was achieving the energy management function of a microgrid through a multi-agent-based control system. In addition to that, it was aimed to advance the multiagent system by introducing Reinforcement Learning as a machine learning approach. As the energy management function grid consumption minimization of the proposed microgrid and the maximum utilization of the renewable generation was under consideration. The proposed system was initially simulated in Python. The simulation results were obtained for the performance of the microgrid ensuring that the modeled agents are capable of minimizing the dependency of the microgrid on the grid in catering for the its loads. The trained system using Reinforcement Learning is applied to the microgrid testbed to simulate the proposed system using real time data. As the outcome of this research a complete software solution for the grid consumption minimization together with a hardware platform to test the real operation can be stated.
  • item: SRC-Report
    Develop a micro grid control platform for sustainable energy management in distribution network
    (2018) Attanayaka, AMS; Jeewandara, JMDS; Karunadasa, JP; Hemapala, KTMU
    The Senate Research Committee (SRC) promotes research by giving funding for research. In addition to the monthly stipend payment, the allocated payments for publications, hardware purchasing, and transportation is highly imperative to achieve the proposed objectives successfully within the time duration. Moreover, guidance of the supervisor who provided the SRC grant for the research is also essential factor to meet the requirements of the research. Microgrids and Battery Energy Storage Systems play a major role in the sustainable and clean energy sector. In this study, an accurate battery model is developed which can represent the electrical and the thermal behavior of the battery and all the battery parameters are investigated experimentally by implementing a test bench for the proposed model and moreover, each of the parameters is validated theoretically by developing a MATLAB simulation. To improve the accuracy of the battery parametrization, battery state of charge (SOC) level is estimated via machine learning algorithms. According to the results, the accuracy of the comprehensive electro-thermal battery model based on electrical and thermal parameters is at a satisfactory level and proves that designing such a model that achieves excellent accuracy and realistic behavior in real-time platform simulators. There are six different time series models are used to estimate the SOC level and according to the performance, auto regressive (AR) model and seasonal auto regressive integrated moving average (SARIMA) models are the best machine learning models for SOC level estimation when battery parametrization.
  • item: SRC-Report
    Study on concrete infilled tubes as compression members in truss type light vehicular bridges
    (2019) Bogahawaththa, PBMR; Gamage, HDH; Baskaran, K
    Applicability of concrete filled steel tubes (CFST) for compression members in truss type steel pedestrian bridges is studied in this research as an economical solution for the lack of pedestrian bridges in Sri Lanka. There are many places in Sri Lanka where people have to travel long distance to cross rivers or access the nearby city for their day to day needs. CFST is a composite material which is getting more popular in the civil engineering industry. So, it is important to examine the properties of CFST as a composite material. Therefore, to achieve a higher span with a lesser cost (steel tonnage), usage of CFST sections for compression members have been accessed in this study. Also, the tendency to local buckling was examined with experimental and numerical simulations. A desk study was carried out focusing Gin Ganga area to identify the problems in the area due to lack of bridges. Two experimental model bridges were tested in this study as one with only hollow Aluminium tubes and other with cement grout filled in selected top chord members. Using a real scale numerical simulation of a CFST bridge model, practical applicability and cost figures were compared with a conventional steel truss bridge. Parker truss was identified as the truss type which consumes the least tonnage for any particular span due to the variable shape of the truss. Experimental testing of two arch bridges showed similar failure mode for both hollow and concrete grout infilled sections (GFAT) incorporated trusses. Nearly 18% capacity enhancement could be observed for the GFAT incorporated truss compared to the truss made of hollow sections. The use of CFST for the compression members in the top chord instead of using large steel sections, will improve the structural performance, while minimizing the cost of a variable height bridge.
  • item: SRC-Report
    Effect of hot air temperature on high moist paddy drying in a conical spouted bed
    (2019) Maduwanthi, MKC; Jayatunga, GK; Amarasinghe, BMWPK
    Parboiled paddy of two varieties namely Samba and Nadu were dried in a lab scale spouted bed dryer. Spouting behaviour, drying kinetics and heat and mass transfer characteristics of parboiled paddy were investigated. The minimum spouting velocity was determined for parboiled paddy of two varieties for three different bed heights. Drying experiments were carried out to analyse the effect of drying temperature and air velocity on drying kinetics, moisture diffusivity and heat transfer coefficient. Results revealed that spouted bed drying operation with elevated temperatures show higher drying rates. The spouted bed dryer spouting at different air velocities had almost similar drying rates at stable spouting state for a selected drying temperature and bed height.
  • item: SRC-Report
    The importance of hospital space and facility utilization and best practices
    (2018) Halwatura, RU
    The following research paper was published from the above-mentioned title " Sri Lankan public hospital space utilization where to next"
  • item: SRC-Report
    Study on the effect of shape of the buildings on energy efficiency and thermal comfort of naturally ventilated houses
    (2018) Halwatura, RU
    The following research paper was published from the above-mentioned title " Effect of building shape, orientation, window to wall ratios and zone on energy efficiency and thermal comfort of naturally ventilated houses in tropical climate"
  • item: SRC-Report
    Assessment of cost of unserved energy for Sri Lankan commercial sector
    (2018) Perera, HYR; Colambage, D. Punsara
    The investments for the improvements of power system to fulfill the energy requirements of electricity customers need to meet the reliability improvement targets. Thus, it is essential to obtain a clear and accurate assessment of Cost of Unserved Energy as an input to the power system planning process. Sri Lanka is currently using an approximated value of Cost of Unservcd Energy calculated in 2002 considering only the Industrial Sector. It is important to update this value. This research was conducted to assess the Cost of Unservcd Energy based on consumer survey method. The survey and analysis parts arc conducted in three separate categories as Industrial, Commercial and Residential. This paper presents the results for Commercial sector, separately for momentary, planned and unplanned non-momentary interruptions. It is expected that the results of this study helps the power sector to provide a better service, taking the views of the customers and the national importance of electricity as an esential input for economic growth.