Ngaopitakkul, Atthapol
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Preferred name
Ngaopitakkul, Atthapol
Alternative Name
Ngaopitakkul, A.
Main Affiliation
Email
atthapol.ng@kmitl.ac.th
60 results
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Item type:Publication, Classification of Capacitor Bank Switching Using Fuzzy Interference Systems in 230 kV Substation(2024-01-01); ; ; Lertwanitrot, PraikanokFlexible AC transmission systems are used for enhancing the stability, transmission efficiency, and reliability of AC grids. Additionally, the most cost-effective devices for compensating reactive power are Mechanically Switched Capacitors (MSCs). This study proposes a novel algorithm for detection and capacitor bank switching transient signals in MSC, to prevent the protective relay maloperation by these transients. The Discrete wavelet transform (DWT) is used for effective time-frequency analysis and detection of measured three-phase current signals. DWT extracts the detailed wavelet coefficients of current signals at levels 1 to 30. In addition, the fuzzy inference system (FIS) has been used to determine the type of switching transient. The proposed combination of FIS and DWT has been tested on 230 kV substation and the result demonstrated precision for the identification and classification of both transient signals in MSC with 88% accuracy rate. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Coefficient comparison technique of discrete wavelet transform for discriminating between external short circuit and internal winding fault in power transformer(2012-01-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effects of Conditional Changes on High-Voltage Direct Current Transmission Line Characteristic(2022-01-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A phase diagram approach to the detection and location of faulty capacitor units in A 115-kV capacitor bank based on unbalanced current arguments(2023-03-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Behaviour analysis of H-bridge high-voltage capacitor banks fault on 230-kV substation using discrete wavelet transform(2023-11-01); The protection of traditional high-voltage capacitor banks relies on an unbalance relay which operates when an internal fuse is blown. However, the unbalance relay cannot indicate the cause of the fault. Thus, an operator wastes time and human resources investigating the fault issues. In this paper, a fault which occurred in a 230-kV power system of Electricity Generating Authority of Thailand was observed by performing simulations using the Power Systems Computer Aided Design (PSCAD) program. The study system based on the double bus station and 72 MVAR capacitor banks was installed in the form of a back-to-back topology. Three scenarios were considered: normal condition, fault occurrence in one capacitor bank and fault occurrence in both capacitor banks. Current characteristics such as the current phase and difference in unbalance current were considered. In addition, discrete wavelet transform was applied to solve the ambiguity of current generated from the PSCAD. The authors’ results suggest that identifying fault events using a coefficient of wavelet is more efficient than relying on the current amplitude. The findings mentioned in this paper can be applied in a traditional power system protection scheme to enhance a system's reliability. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An Evaluation Study on Electric Appliance Characteristics and Load Patterns in Residential Buildings(2026-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Impact of lightning impulse voltage waveshape front time between 1.2/50 μs and 4/50 μs on back-flashover voltage across insulator of 230 KV transmission tower(2014-02-04); This paper is a study of the behavior of back-ashover on the insulators with various lightning voltage waveshapes. The simulated lightning strikes on high voltage 230 kV transmission towers using Alternative Transients Program/Electromagnetic Transients Program (ATP/EMTP) to consider back-ashover voltage across insulators. The standard of lightning voltage waveshape (1.2/50 μs) will be compared with the other lightning voltage waveshape front time (4/50 μs) in this paper. The results are shown that the lightning voltage waveshape plays an important role for the back-ashover voltage across insulators as well as the tower footing resistance and the lightning stroke current. © 2014 ICIC International. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Inrush current analysis for switching large shunt capacitor bank in a 230 kV substation system(2013-12-01); This paper presents the simulation and investigation of switching large shunt capacitor bank in a 230kV Thailand substation system. Simulation is performed using PSCAD/EMTDC. The inrush current is generated by energizing of the 4×72 Mvar, 230 kV shunt capacitor banks. The purpose is to observe the inrush current to ensure safe and successful operations of the shunt capacitor banks. In addition, the effects of parameters such as sizing of current limiting reactor (CLR), pre-insert resistor (PIR) and 6% detuning reactor are investigated. The results of simulations are shown that the 6% detuning reactor can reduce inrush current more than other methods. © 2013 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Discrete wavelet transform and back-propagation neural networks algorithm for fault classification on transmission line(2009-12-16); This paper proposes a technique using Discrete Wavelet Transform (DWT) and Back-Propagation Neural Network (BPNN) to identify the fault types on single circuit transmission lines. The ATP/EMTP is used to simulate fault signals. The mother wavelet daubechies4 (db4) is employed to decompose high frequency component from these signals. The variations of first scale high frequency component that detect fault are used as an input for the training pattern. The result has shown that the proposed technique gives satisfactory results. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Discrete wavelet transform and back-propagation neural networks algorithm for fault classification in underground cable(2011-07-26); ; ;