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Author: search.filters.author.Pothisarn, ChaichanSubject: search.filters.subject.Wavelet transform

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    Development of overcurrent relay based on wavelet transform for fault detection in transmission line
    (2024-12-01)
    Ananwattanaporn, Santipont
    ;
    Lertwanitrot, Praikanok
    ;
    Ngaopitakkul, Atthapol
    ;
    Pothisarn, Chaichan
    This study proposes a protection relay using a microcontroller to detect and classify faults in transmission lines based on the wavelet transform. An experimental model was constructed from an actual 115 kV transmission system prototype. The current signal was observed based on the fault type, phase, and position. Clark’s transform and the discrete wavelet transform (DWT) were applied to transform signals for analysis. Moreover, the performance of fault detection based on the output signals of Clark’s transform (alpha sequence, beta sequence, and zero sequence current) was compared to the performance of the alternative proposed fault detection method, which is based on the combining factor between alpha and beta sequence current. In addition, the influence of DWT level on fault analysis is also considered and is used to confirm the accuracy of fault detection. Results show that the proposed method is efficient for fault detection and classification. This finding allows the researcher to choose the appropriate analytical method. Moreover, it can also be used as the basis for overcurrent relay algorithm design in the effort to develop more advanced technologies.
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    The study on wavelet coefficient behavior of simultaneous fault on the hybrid between overhead and underground distribution system
    (2019-05-01)
    Pothisarn, Chaichan
    ;
    Jettanasen, Chaiyan
    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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    Application of support vector machines algorithm for discriminating between external fault and internal winding fault in power transformer
    (2014-02-04)
    Ngaopitakkul, Atthapol
    ;
    Jettanasen, Chaiyan
    ;
    Leelajindakrairerk, Monthon
    ;
    Pothisarn, Chaichan
    ;
    Suechoey, Boonlert
    The differential relaying principle is used for protection of medium and large power transformers. In the past decade, several decision algorithms have different solutions and techniques. This paper proposes a new technique using discrete wavelet transform (DWT) and support vector machines (SVM) to classify and discriminate between external fault and internal fault in power transformer. The DWT is used to detect the high frequency components from fault signals. The variations of first scale high frequency component that detects fault are used as input for the SVM. The proposed method gives satisfactory accuracy, and will be very useful in the development of a modern protection scheme for electrical power transmission systems. © 2014 ICIC International.
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    Identifying types of simultaneous fault in transmission line using discrete wavelet transform and fuzzy logic algorithm
    (2013-07-17)
    Ngaopitakkul, Atthapol
    ;
    Apisit, Chaowat
    ;
    Bunjongjit, Sulee
    ;
    Pothisarn, Chaichan
    In the literature for fault classification, several decision algorithms have different solutions and techniques. These research works have been rarely mentioned about simultaneous faults in transmission systems. This paper presents the decision algorithm for identifying types of simultaneous fault along the transmission line. Decision algorithms based on discrete wavelet transform (DWT) and fuzzy logic are investigated. The analysis of fault signals is performed using DWT. The DWT is used in order to detect the high frequency components. The coefficient details (phase A, B, C and zero sequence of post-fault current signals) of DWT at the first peak time that positive sequence current can detect fault, are performed as an input for the fuzzy logic. The result shows that the accuracy of the proposed algorithm is highly satisfactory. © 2013 ICIC International.
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    The protection of transmission network systems using Discrete Wavelet transforms
    (2012-09-01)
    Ngaopitakkul, Atthapol
    ;
    Pothisarn, Chaichan
    This paper proposes a novel protective relay algorithm to protect transmission systems using Discrete Wavelet Transforms (D WT). Fault conditions are simulated using PSCAD/EMTDC in order to obtain current signals. Various cases based on Thailand electricity transmission systems are carried out to verify the validity of the proposed technique. The maximum coefficients of the positive sequence current obtained from all buses are compared in order to detect the faulty bus on a three-bus transmission network with a loop structure. The first peak time of positive sequence current obtained from the faulty bus is used as input data for travelling wave equation. The coefficient ratio between buses that the fault occurs is calculated so that the proper protective relay sequence can be selected. The result is shown that the proposed algorithm is capable of locating the fault position as well as arranging the protective relay sequence, with satisfactory accu¬racy results, and is suitable for all types of fault that occurs in different sections on the transmission lines. © 2012 ICIC International.
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    Discrete wavelet transform and back-propagation neural networks algorithm for fault location on single-circuit transmission line
    (2008-01-01)
    Ngaopitakkul, Atthapol
    ;
    Pothisarn, Chaichan
    This paper proposes a technique using discrete wavelet transform (DWT) and back-propagation neural network (BPNN) for locating of fault location on single circuit transmission lines. The ATP/EMTP was used to simulated fault signals. The mother wavelet daubechies4 (db4) is employed to decompose, high frequency component from these signals. The first peak time in first scale of each bus that can detect fault are used as input pattern for the training pattern. It is shown that the proposed technique gives satisfactory. © 2008 IEEE.