Now showing 1 - 7 of 7
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    Fault classification in transformer using low frequency component
    (2017-12-13) ; ;
    Asfani, Dimas Anton
    ;
    Negara, I. Made Yulistya
    Transform is a vital equipment in power system that need protection system in order to provide fast and correct response when disturbance occur in system. So, this paper proposed internal and external fault classification in Transformer using algorithm based on discrete wavelet transform (DWT). Low frequency component from DWT has been used to create condition for algorithm. The proposed algorithm has been test using transmission line connected to transformer experimental setup on laboratory level. The result from proposed algorithm shown satisfactory result with 100% accuracy in both internal and external fault in transmission line connected transformer system.
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    Item type:Publication,
    Influence of wind farm on distribution system: Current characteristics during fault occurrence
    In this past few years, installation of distributed generator (DG) has become topic of interest in many countries due to rapid increase in energy and environmental issue. Generating power from renewable source has been proposed to compensate fossil fuel that is currently depleted. Wind power is one of the renewable energy sources that gains a huge attention, and many utilities are connecting wind power to distribution system. This number is going to get higher in the near future. Research on influence of wind power on system must be done in order to ensure the reliability of power system. This paper aims to study an impact of wind power-integrated distribution system when fault occurs in the system for various conditions. Many factors capable of changing system characteristics have been taken into account such as distribution system consisting of multi-wind power generation, size of wind power generation, fault type, and location of fault. Distribution system under this study is modeled based on 22 kv distribution network of Provincial Electricity Authority (PEA) in Thailand. Simulation will be done by using PSCAD/EMTP. Result obtained from case studies will be used to analyze and evaluate the effect of installation of wind power. The result indicates that the DG contributes significant fault current to the system when fault occurs.
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    Item type:Publication,
    Differential protection schemes for classification of fault detection between external fault and internal winding fault in transformer using probabilistic neural network
    (2012-12-01) ;
    Klomjit, J.
    ;
    Positharn, C.
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    Bunjongjit, S.
    ;
    This paper proposes an algorithm based on a combination of discrete wavelet transform (DWT) and probabilistic neural network (PNN) for discriminating between external fault and internal winding fault in power transformer. The coefficients of the first scale from the DWT that can detect fault are investigated. The maximum coefficients details (cD1) from DWT in first scale at 1/4 cycle of phase A, B, C and zero sequence for post-fault differential current waveforms have been used as an input for the training process of the PNN in a decision algorithm. Various cases studies based on Thailand electricity transmission and distribution systems have been investigated so that the algorithm can be implemented. The results show that the proposed algorithm is capable of performing the fault detection with satisfactory accuracy. © 2012 IEEE.
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    The study on wavelet coefficient behavior of simultaneous fault on the hybrid between overhead and underground distribution system
    This paper proposed the study on behaviour and characteristic of wavelet coefficient in case of simultaneous fault occurrence on hybrid transmission system. The ATP/EMTP software has been used to simulate 115-km hybrid transmission line that modelled after on part of PEA distribution system. The case study system is 40 km distribution line with overhead line on first 20 km section and underground cable on the second half. The Discrete Wavelet Transform (DWT) has been used to analyse fault signal. Various factor that can affect system characteristic such as inception angle, location, and type of fault has been taken into consideration. The result shown the significant change in coefficient of high frequency component when simultaneous fault occurs compared to single fault especially in hybrid distribution system when fault occur on both overhead and underground cable, thus result in problematic analysis of coefficient and complexity in design suitable algorithm. This change in system characteristic must be taken into consideration when develop protection system in order to achieve the satisfactory performance with even more complex power system in the future.
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    An experimental setup investigation to study characteristics of fault on transmission system
    (2015-01-01)
    Yindeesap, P.
    ;
    ; ;
    This paper proposes the experimental setup for studying the characteristics of fault caused by balance and unbalance on a transmission system. The parameters of transmission system (inductance and capacitance) are calculated based on forms of transmission tower, size of conductor, types of conductor and arrangement of transmission line and, they normalized to obtain the values in the π- equivalent circuit model at voltage level of 400 V. In addition, the ATP/EMTP is used to compare the simulated results with the experimental setup in order to show the advantage of the experimental setup. The obtained results show that the similarity between the two waveforms. The experimental setup will be useful in the development of short-circuit protection system in laboratory.
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    Discriminating among inrush current, external fault and internal fault in power transformer using low frequency components comparison of DWT
    (2012-12-01) ; ;
    Klomjit, Jittiphong
    ;
    A technique using discrete wavelet transform (DWT) in order to discriminate among inrush current, internal fault, and external fault has been proposed. Daubechies4 (db4) is employed as mother wavelet in order to decompose low frequency components from fault signals. A ratio between per unit differential current and per unit time is calculated and performed as comparison indicator. The results obtained from the proposed technique have good accuracy to discriminating fault in the considered system. © 2012 IEEJ Industry Appl Soc.
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    Study on coordination of protective relays in distribution system with distributed generation
    (2020-01-01) ;
    Songsukthawan, Panapong
    ;
    ; ;
    In the recent decade, many countries around the globe have been increased the proportion of electrical power generation from renewable energy sources, which results in rising in the penetration level of distributed generation (DG). However, the installation of DG into the distribution system may raise many issues that can impact the distribution system in both the technical and economic aspects. When DG is connected to a distribution system, it can affect the performance of the system and the protective device already installed owing to the change of voltage level, short-circuit level and direction of power flow in the system. For this reason, a protective device may cause the malfunction because the bus impedance of the system is changed; this will result in a change of the current in each bus. This paper aims to study the coordination between the protective relay and the DG installed into the distribution system. The distribution system under investigation is a part of the Provincial Electricity Authority (PEA). Under this research, DG data that are connected to the PEA distribution is used. The simulations are performed using digital simulation and electrical network calculation program (DIgSILENT).