Yutthagowith, Peerawut
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Yutthagowith, Peerawut
Alternative Name
Yutthagowith, P.
Yutthagowith, Pearawut
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peerawut.yu@kmitl.ac.th
29 results
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Item type:Publication, Fast and Effective Technique in Evaluation of Lightning Impulse Voltage Parameters(2021-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Partial Discharge Measurement Based on an Inductive Mode Air-Core Sensor(2020-03-01); In this paper, an alternative technique for partial discharge (PD) measurement using an air-core sensor is proposed. The air-core sensor consists of an inductive mode air-core coil and the appropriate additional resistor. The approach for inductive mode enhancement of an air-core coil is presented. In the inductive mode operation, an output voltage which is proportional to an induced voltage from the air-core coil is utilized to determine PD currents and charges by a numerical integration. In the design process of the air-core sensor, parameter estimation with a computation algorithm is employed for extracting unknown circuit parameters of the air-core coil from a unit step response. These estimated parameters are crucial in an effective design of the PD measuring system. With the design circuit parameters, experiments in PD measurement were performed. From experimental results, the developed system has promising performance, and the sensitivity is in the range of a few picocoulombs. From this achievement, the proposed technique is a choice in PD measurement for high-voltage equipment in the laboratory and in the on-site measurement. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Improved Least-Square Prony Analysis Technique for Parameter Evaluation of Lightning ImpulseVoltage and Current(2016-02-01); This paper represents a fast curve-fitting technique for evaluation of either lightning impulse voltage or the current base curve. The technique based on least-square Prony analysis employs the double integration of the recorded waveform for waveform evaluation. The undesirable effect of noise exiting in Prony analysis technique is mitigated. The base curve formula is written in the complex form of the double exponential function. A decomposition technique is utilized for determination of the base curves of full lightning impulse voltages with oscillations and of lightning impulse currents. To verify the performance of the proposed method, the base curves reconstituted from the developed method were compared with the curves reconstructed from a nonlinear least-square regression prescribed in the standard. The execution time of the proposed method is much shorter than that of the conventional method because it does not need the iteration process. With noise immunity characteristics and avoidance of recorded waveform distortion, the results from the proposed technique based on the normal implementation are remarkably accurate. The results of this study indicated that the proposed method is the powerful one to apply for lightning impulse voltage and current base curve evaluation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Development of a Rogowski Coil-Based Lightning Current Measuring System with Wide Frequency Bandwidth for Wind Turbines(2026-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Resonant power frequency converter and application in high-voltage and partial discharge test of a voltage transformer(2021-04-01); This paper presents application of a resonant power frequency converter for high-voltage (HV) and partial discharge (PD) test of a voltage transformer. The rating voltage, power, and frequency of the system are 70 kV<inf>rms</inf>, 40 kVA, and 200 Hz, respectively. The testing system utilized the converter feeding to an HV testing transformer connected to a conventional partial discharge detection system. The converter system comprising a rectifier and insulated-gate bipolar (IGBT) switches with the H-bridge configuration was applied as a low-voltage source instead of a conventional motor-generator test set which requires large space and high cost. The requirements of the test according to the standards are quality of the test voltage and the background noise level. The required voltage must have the different voltage (DV) and total harmonic distortion (THD<inf>v</inf> ) in the acceptable values of less than 5%. The DV is defined as the difference of the root mean square and peak voltages in percent. The required background noise level must be lower than 2.5 pC. Simulations and experiments were performed for verification of the developed system performance in comparison with those of the previously developed system based on the pulse width modulation converter. It is found that the developed system can provide the testing voltage with the DV and the THD<inf>v</inf> of lower than 1% and the background noise level of lower than 1 pC. Considering this achievement of promising performance, the developed system is an attractive choice for the HV and PD testing of voltage transformers in real practice. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A Simple Mathematical Expression for Nonlinear Resistive Characteristics of Metal Oxide Elements in Lightning Surge Analysis(2025-06-01); Baba, YoshihiroAccurate simulations of transient phenomena in electric power systems with metal oxide varistors (MOVs) or lightning arresters (LAs) using the finite-difference time-domain (FDTD) method for solving Maxwell's equations require simple and accurate representations of MOVs or LAs. By representing a small cell within a MOV or LA with resistivity (ρ) dependent on electric field (E), these components can be modeled in three dimensions and seamlessly integrated into FDTD simulations. Achieving computational efficiency in FDTD simulation necessitates avoiding iterative computations for ρ from E. Hence, there is a significant need for a simple and accurate mathematical expression of ρ in terms of E. This study presents a methodology for deriving a three-coefficient exponential function from experimental data. By using integration properties, this method transforms nonlinear characteristics into linear ones without iterative processes or uniform data sampling. It also incorporates data weighting and outlier discrimination for enhanced accuracy. Comparative analysis with previous methods based on the ordinary least squares method and experimental data, using an applied current with a rise time of approximately 8 μs, confirms high accuracy and effectiveness in computing residual voltages resulting from impulse current injection using the FDTD method. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, PEEC simulation of lightning over-voltage surge with corona discharges on the over head wires(2020-03-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effective simulation approach for lightning impulse voltage tests of reactor and transformer windings(2020-10-16); In this paper, an effective simulation method for lightning impulse voltage tests of reactor and transformer windings is presented. The method is started from the determination of the realized equivalent circuit of the considered winding in the wide frequency range from 10 Hz to 10 MHz. From the determined equivalent circuit and with the use of the circuit simulator, the circuit parameters in the impulse generator circuit are adjusted to obtain the waveform parameters according to the standard requirement. The realized equivalent circuits of windings for impulse voltage tests have been identified. The identification approach starts from equivalent circuit determination based on a vector fitting algorithm. However, the vector fitting algorithm with the equivalent circuit extraction is not guaranteed to obtain the realized equivalent circuit. From the equivalent circuit, it is possible that there are some negative parameters of resistance, inductance, and capacitance. Using such circuit parameters from the vector fitting approach as the beginning circuit parameters, a genetic algorithm is employed for searching equivalent circuit parameters with the constraints of positive values. The realized equivalent circuits of the windings can be determined. The validity of the combined algorithm is confirmed by comparison of the simulated results by the determined circuit model and the experimental results, and good agreement is observed. The proposed approach is very useful in lightning impulse tests on the reactor and transformer windings. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An Accurate Evaluation of Switching Impulse Voltages for High-Voltage Tests(2022-07-01)For assessment of the insulation performance of high-voltage (HV) equipment installed in extra-high-voltage (EHV) systems, switching impulse voltage tests are performed in an HV testing laboratory. The waveform parameters of the switching impulse voltages are defined by peak voltage (U<inf>p</inf>), time to crest (T<inf>p</inf>), and time to half (T<inf>2</inf>) according to IEC 60060-1. In this paper, a new, simplified, and accurate approach used for determination of the waveform parameters of the switching impulse voltages is presented. The formula used in the evaluation of T<inf>p</inf> was derived from analytically simulated two-exponential waveforms, where T<inf>p</inf> and T<inf>2</inf> are in the ranges of 20 µs to 300 µs and 1000 µs to 4000 µs, respectively. The accuracy of the proposed approach was validated by the waveforms collected from the test waveform data generator (TDG) provided by IEC 61083-2, simulations, and experiments. It is found that the accuracy of the proposed approach is relatively higher than the expressions provided by IEC 60060-1 and previously developed. The proposed method is an alternative and useful approach for evaluating the waveform parameters of the standard switching impulse voltage. - Some of the metrics are blocked by yourconsent settings
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