ERU - 2019
Permanent URI for this collectionhttp://192.248.9.226/handle/123/19528
Browse
Recent Submissions
- item: Conference-AbstractSteady state voltage regulation using custom power devices in distribution networks(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Sanju, KAY; Samarawickrama, SB; Fernando, MAJ; Senaka, AK; Prasad, WD; Abeysooriya, RDistribution Generation (At Medium Voltage (MV) and Low Voltage (LW)) has changed convectional distributional networks by allowing bi-directional power flow, also there are unusual types of loads like Electric vehicle chargers which draw large currents for a short duration of time. So that active distribution system needs to be properly managed and coordinated. Steady State Voltage Management is a such issue. The study is to overcome the above stated voltage issues implementing a Custom Power device Static Var Compensator (STATCOM).
- item:Inadequacies of analysis of pre-construction activities on cost overruns in construction projects(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Shehara, PLAL; Ranasinghe, M; Prasad, WD; Abeysooriya, RCost overrun is considered as one of the critical issues in the construction sector projects in many of the developing countries. It has been identified that pre-construction factors affect mainly on time and cost overruns in construction projects. The focus here is on mainly four pre-construction factors which are selected from review of literature. They are conducting geotechnical site investigations, identification of availability of sufficient knowledge to do the project, identification of availability of skilled labour, identification of required material, machinery and equipment. This research study attempts on identifying the severity of the adequacy of these four pre-construction factors on cost overruns and to develop a relationship between cost overrun variation with the adequacy level of analysis of those pre-construction factors. A thorough review of literature was done to identify the four pre-construction factors and then a questionnaire survey was conducted to obtain the responses from industry experts regarding construction cost overruns related with the adequacy levels of analysis of four factors for a selected project. The survey data obtained were analysed by determining Relative Importance Index, Regression Analysis and Sensitivity Analysis techniques. The results obtained from the analysis techniques are interpreted under this research study based on the limitations.
- item: Conference-AbstractDevelop a series arc fault detector to minimize the risk of domestic electrical fires(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Somathilaka, SP; Sumathipala, WMKS; Senarathna, NT; Hewapathirana, HE; Hemapala, KTMU; Lucas, JR; de Silva, PSN; Prasad, WD; Abeysooriya, RThis study is about the development of a series arc fault detector, which can be used to minimize the risk of domestic electrical fires. Electricity is a common cause of fire in residential buildings. If a parallel electrical arc fault is developed it can be detected from the residual current circuit breaker. If the arc current is higher than the rated current of the circuit, it can be detected from the miniature circuit breaker. But, if a series arc fault is developed which is lower than the rated current of the circuit, it cannot be detected by those conventional devices. In this study, an arc generator which could be connected to any electrical equipment was developed for generating a series arc fault. A set of different methods such as Fast Fourier Transform, Derivative Analysis, Discrete Wavelet Transform and Continuous Wavelet Transform were used to analyze the current and voltage waveforms in the presence and absence of series arc fault. However, only some of those methods yielded promising results. Moreover, an analysis about the parameters which will affect the risk of fire was conducted. Further research regarding the development of the series arc fault detector is in progress.
- item: Conference-AbstractImproved maximum power point tracking of solar pv systems for faster and accurate convergence(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Wanigasekara, DC; Hettiarachchi, UM; Weerasinghe, WPTS; Ranasinghe, ERIACC; Prasad, WD; Abeysooriya, RThe maximum power of a PV module represents variations due to temperature, irradiation and load. In the conventional mode maximum power point tracking algorithms are applied to maximize efficiency, reliability by constantly extracting maximum power. The conventional methods that mentioned in literature have several disadvantages in terms of efficiency, accuracy and flexibility specifically under varying weather conditions. It is mainly because of non-linearity in PV module current-voltage characteristics as well as DC-DC converters. Under this project new intelligent control methods for maximum power point tracking will be tested. Basically, fuzzy logic-based hill climbing method will be proposed and tested to obtain faster and accurate converging to the maximum power point during steady state and varying weather conditions. This artificial intelligence approach would simplify exiting methods and provide with proper modeling of nonlinear systems. In achieving this goal, maximum power point system consisting PV module, buck, boost, buck-boost converter, fuzzy logic controller is designed and simulated using Mat lab Simulink and experimentation studies would be carried out. In the latter stage, it is proposed to extend this project by combining fuzzy logics and neural networks so that the system can identify its maximum power point by itself through self-learning rather implementing only an algorithm as in conventional methods.
- item: Conference-AbstractObtaining the magnetization characteristic of a transformer using inrush current waveforms(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Jalthotage, IU; Aluthge, CD; Dharmawardana, KDOV; Wijeratne, KAL; Lucas, JR; Prasad, WD; Abeysooriya, RThe magnetization characteristics of installed transformers are quite often unknown, or different from those documented due to ageing. Further, a precise method of modelling the nonlinear flux-curve of a transformer is a requirement for electromagnetic transient studies. A reliable method is thus needed to determine the magnetization characteristics of installed three-phase transformers. Transformer parameters are usually determined in the manufactory, mainly using the open circuit and short circuit tests. However, it is not possible to conduct these tests in the field.
- item: Conference-AbstractCost effective battery storage for intermittency of solar(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Nayanathara, PMD; Perera, HS; Abeyrathne, RAHMPNN; Lucas, JR; Prasad, WD; Abeysooriya, RRenewable energy, especially Solar Energy, has become a popularly sought solution for the current energy situation in Sri Lanka. It is included in the ‘Long Term Generation Expansion Plan of the Ceylon Electricity Board (CEB)” as well [1]. However, the unpredictable, varying and intermittent nature of the solar hinder all these plans. Wide varying nature of solar power is such that the daily infeed may vary within 20% to 90% of the installed during the same week. Said constant power fluctuations and the inability to control the infeed utilizing system inertia lowers the quality of service provided to the CEB by the power producers. This impacts adversely on the interest towards solar from both the sides; CEB and the power producer. To overcome this problem, the CEB recommends solar producers to install a battery storage to store the energy produced during daylight hours enabling that energy to be utilized later. This recommendation has not been welcomed by the producers due to cost related issues. Hence, this research proposes a more economically feasible solution for the discussed matter. It consists of a forecasting system to predict the solar power output sufficiently in advance to the CEB System Control Center and a relatively smaller battery storage equipped with an automatic switching mechanism to maintain the predicted output. This value-added solar output should be rewarded under an updated tariff scheme.
- item: Conference-AbstractApplicability of enterprise resource planning in human resource management in high-rise building construction(Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 2019-07) Bosco, AJ; Wickramasinghe, BMSM; Disaratna, V; Prasad, WD; Abeysooriya, RHuman Resource (HR) Management is of great significance in construction industry as it has a direct impact on the performance of construction projects. Mostly construction of high-rise buildings faces the challenge of managing its HR with the rapid design and development of them. Thus, the industry has come out with some strategies to overcome them. However, these strategies did not provide a complete solution. Therefore, construction industry needs an appropriate way to manage its HR and thus calling for an Information Technology (IT) solution which in turn is Enterprise Resource Planning (ERP) system. Consequently, the aim of investigating the applicability of ERP in managing HR in high-rise building construction became a paramount concern in this research. Accordingly, this research was adopted a qualitative approach with a set of semi-structured interviews focusing industrial professionals and ERP experts to accomplish the aforementioned aim. Subsequently, the collected data were analyzed rigorously through content analysis. The relationship between information from the literature sources and from the industry professionals with respect to main advantages of ERP system and key features of ERP system, it is recommendable to be used in managing HR through overcoming HR challenges completely in high-rise building construction.