Kunakorn, Anantawat
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Preferred name
Kunakorn, Anantawat
Alternative Name
Kunakorn, A.
Kunakorn, Anatawat
Main Affiliation
Email
anantawat.ku@kmitl.ac.th
25 results
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Item type:Publication, Polarization and depolarization current characteristics of thermally stressed stator bars(2019-07-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Transient equivalent circuit of a horizontal grounding electrode(2012-12-31); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Studies of Electrical and Thermal Characteristics of Natural Ester Immersed Transformer Compared with Mineral Oil Immersed and Palm Oil Immersed Transformer(2018-11-14) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Frequency dependence parameter analysis of underground cables with and without joint(2018-06-29); This paper represents the dielectric investigation of XLPE power cables with and without cable joint (premolded joint) by using polarization and depolarization current (PDC) measurement. To investigate the polarization phenomena of the underground cable (case 1) and the underground cable with the premolded joint (case 2), the XLPE cables with the cross-section area of 240 mm<sup>2</sup> and 5 m long with rate voltage of 12/20(24) kV with and without premolded joint were used in the experiment. In this research work, the DC voltage of 1,000V was applied to insulation system for measuring polarization current, i<inf>pol</inf>(t). Then, suddenly disconnected the DC applied voltage source to short circuit the tested cable to measure depolarization current, i<inf>dep</inf>(t), In case 1, the PDC measurement was only for 100 seconds due to its homogeneous insulation of XLPE cable; only conduction current and interfacial polarization current with short relaxation time existed. In case 2, the PDC measurement was done for 2,000 seconds. In this case the polarization current was from XLPE cable mentioned and the interfacial polarization current from the barrier between XLPE cable and cable joint. From the experiment, the frequency dependence of the complex capacitance and dielectric dissipation factor of the underground cable and the underground cable with the premolded joint were analyzed. It is found that the trend of real part of the complex capacitance and the conduction loss of both case studies is not much different. However, the trend of imaginary part of the complex capacitance and polarization loss of both case studies is clearly different. Two peaks of imaginary parts of complex capacitance and polarization loss of the underground cable with joint is from XLPE and the junction of XLPE and joint. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study of a partial discharge location technique for power cables using high frequency current transducer(2018-11-01); ; Pumyoy, SuparatIn this paper, a partial discharge location technique for power cables was studied. PD signals are measured by high frequency current transducer which has been experimentally verified and installed at the end one (near end) of cable. The standard PD pulse calibrator with the charge of 200 pC was used to investigate the PD location at various position along the cable with total length is 37.925 m. The PD location method, time domain reflectometry (TDR) is used to locate the PD defect along the cable, which essentially based on the f travelling wave theory. From the experimental results of PD location, the highest error of PD location by time domain reflectometry method is 0.859 % at PD defect point (x) of 21.41 m. From this experiment, the proposed technique can be applied to further practical application and research related to PD location. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Implementation of a Rogowski's coil for partial discharge detection(2017-01-30); This paper presents the implementation of a Rogowski's coil for a special purpose on partial discharge detection. A numerical integrator and a filter are used with the Rogowski's coil to calculate partial discharge current and apparent charge. Implementation of the Rogowski's coil in a laboratory, such as a unit step response, linearity of the measurement, and partial discharge detection, is performed. It is found that the partial discharge current and the apparent charge which are detected by the Rogowski's coil are agreed well with the measurement from the conventional method. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Analysis of frequency converters for PD test(2017-10-27); ; Potivejkul, SiriwatThis paper presents the analysis of an AC-AC converter used in partial discharge test. In this paper, the analysis of the frequency converter is separated into two parts. Firstly, the converter models are simulated by a circuit simulation program for comparing noise signals generated by the 2-level SFC and 5-level SFC. The frequency of the converter was set to be 200 Hz. With the help of the simulator, the approach for noise mitigation with filter application is designed and applied to the PD test system. In the second part, the developed static frequency converters are used in the partial discharge tests for confirming the simulation results. From all simulated and experimental results, it can be concluded that the 5-level SFC has high efficiency, low generated noise signal, and also very attractive for using in partial discharge test. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Design of counterpoise grounding electrodes for transmission towers in high soil resistivity area(2018-10-23); This paper presents an approach based on numerical electromagnetic analysis for design of counterpoise grounding electrodes for transmission towers in high soil resistivity area. Frequency dependent soil parameter impulse characteristics of counterpoise electrodes are taken into account in the design process. The transient characteristics of the counterpoise electrodes calculated by a representative electromagnetic approach named the partial element equivalent circuit (PEEC) method are presented in the time and frequency domains. In cases of the time domain simulation, the standard lightning impulse current waveforms collected from IEC 62305 are taken into account. The soil ionization is neglected for the conservative cases. It is noticed that in cases of long counterpoise electrodes, the capacitive effect at the middle frequency range is found. This effect leads to the magnitude of the electrode impedance to be lower than its resistance. Neglecting frequency dependence of soil parameters, the impulse grounding resistance (impedance) of the 4-leg grounding electrode in the high resistivity soil area cannot be achieved to the specified utility's value of 20 Ω due to effect of impulse effective length. However, when the frequency dependence of soil parameters is included in the design, the grounding resistance can be achieved to the specified utility's value. Therefore, the grounding resistance of 20 Ω is still possible for the grounding system design according to the utility's requirement. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, PWM AC chopper control schemes for energy saving of single-phase induction motors(2012-12-01); This paper presents control schemes for energy saving of a capacitor start and run type single-phase induction motor using a PWM AC Chopper to adjust the appropriate motor voltage under various load levels. MATLAB/Simulink is used for the simulation. The main winding stator current is used to feedback for minus with the appropriate current obtained from the multiple of the auxiliary winding stator current and the appropriate constant. Then, the error is sent to a PI Controller. The output of the PI controller will be compared with a carrier to generate PWM signals for controlling all bidirectional switches of the single-phase AC chopper. With the proposed scheme under any motor load level, the motor will always operate at the rated speed, which allows for high efficiency and energy saving. The motor energy saving is 43.97%, particularly at light load. © 2012 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Design and construction of a quad-pole coupling device for partial discharge tests(2017-11-03); This paper presents design and construction of a quad-pole coupling device which is used for measurement of PD signal and AC voltage as the conventional partial discharge testing according to IEC 60270[1]. The developed coupling device is capable to measure AC voltage at frequencies of 50 Hz and 200 Hz. Lower limit and Upper limit frequencies of the developed coupling device are 30 kHz and 20 MHz, respectively. The remarkable feature of the developed coupling device has the accuracy in PD signal measuring and the ability in eliminating noise signal such as unwanted AC signal at PD measuring point and interference signal. Therefore, in the design procedure based on OrCAD computer program, two main parts being the AC signal measuring part and the PD signal measuring part are considered. In the AC signal measuring part, the proper impedance was chosen to achieve appropriate voltage divide ratio and accuracy in PD signal measuring. In the coupling device, voltage surge protective device was installed to protect the PD measuring part. In PD signal measuring part, the value of the components in PD signal measuring circuit must be chosen properly to achieve the determined upper and lower limit frequencies and consider the value of the matching resistance. In this part, noise signal elimination must be considered to gain less effect to PD signal, otherwise the PD signal waveform will distort. From this intensive study, the coupling device circuits were designed and constructed and then, they were tested at 50 Hz and 200 Hz AC Voltage supply. The results of the developed coupling device are compared to that of the reference coupling device in the high voltage laboratory of King Mongkut's Institute of Technology Ladkrabang. The developed coupling device can be used in conventional PD testing according to IEC 60270. The comparisons of the simulated and experimental results show that the performance of the developed coupling devices as same as the reference coupling device.