Kunakorn, Anantawat
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Preferred name
Kunakorn, Anantawat
Alternative Name
Kunakorn, A.
Kunakorn, Anatawat
Main Affiliation
Email
anantawat.ku@kmitl.ac.th
7 results
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Item type:Publication, The Study of Polarization and Depolarization Current Measurements on Service-Aged 22 kV XLPE Underground Cables with Presence of Water Trees(2022-01-01); ; This paper represents the condition assessment of service-aged 22 kV XLPE insulated underground cables. From the investigation, the water trees were detected in the insulation layer. The visual inspection of underground cables reveals the presence of copper carbonate contaminated on the copper tape layer. Some underground cables have the discontinuity of the copper tape layer. To evaluate the insulation condition of the underground cables, the polarization and depolarization current (PDC) measurements were performed on both the service-aged and the new (or unused) cables. The underground cables to experiment with the length of insulation screen equal to 1 m were prepared. In this research, the PDC measurements were performed on different aspects, i.e., the testing voltages (600 V, 800 V, and 1000 V), the testing positions, the effect of the discontinuity of the copper tape layer which occurred during service, the influence of the presence of copper carbonate, and the influence of water trees in XLPE cables. The dielectric response of the underground cables by using polarization and depolarization current measurements can diagnose the problems in service-aged underground cables, but this paper needs more test data for accurate interpretation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dielectric response analysis for cable joint problems in medium voltage underground cable system(2020-01-01); This paper represents the investigation of dielectric response analysis of a cable system composed of a medium voltage XLPE underground cable, a heat-shrink cable joint and a heat-shrink cable termination. A 12/20(24) kV single core XLPE underground cable with the nominal cross-section area of 240 mm<sup>2</sup>, three pieces of 22 kV cable joints, and eight pieces of 22 kV cable termination were prepared for the experiment. Then, polarization and depolarization current (PDCs) measurement were performed. The experiments were divided into two parts. The first part was composed series of three tests, A — C, and the second part consisted series of two tests, D — E, as follows: Test A examined dielectric response of a 6 m healthy XLPE underground cable, Test B examined dielectric response of a 6 m healthy XLPE underground cable with two healthy cable terminations, Test C examined dielectric response of a two of 3 m healthy XLPE underground cable with healthy cable terminations connected by a healthy cable joint, Test D used the test object similarly as case C but the cable joint was contaminated with copper particles, and Test E used the test object similarly as case C but the cable joint was contaminated with tiny pieces of water blocking. From the experiment, the PDCs and the derived dielectric parameters such as geometrical capacitance, insulation resistance, polarization index, depolarization index, charge difference curve and charge ratio curve were analyzed. The PDCs and the derived parameters were found different for each case of study as details in this paper. Besides, the charge ratio proposed by authors is a valuable parameter for the diagnosis of insulation system of high voltage equipment. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A CASE STUDY ON DIELECTRIC RESPONSE MEASUREMENT OF HIGH VOLTAGE GENERATOR INSULATION SYSTEMS(2023-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study of asymmetrical leakage currents of metal oxide surge arrester due to multiple current impulses(2020-09-13); This paper presents the study of asymmetrical leakage current of metal oxide surge arrester (SA) after being tested with multiple current impulses. The study is made using 2 SAs specimens of 21 kV rated voltage, 5 kA nominal discharge current. The experiment is divided into 4 steps; 10 shots of positive discharge current impulses, reference voltage measurement, 5 shots of negative discharge current impulses and reference voltage measurement. Initial conditions of the SAs are assessed prior to the testing: temperature measurement, 1 mA reference voltage and resistive leakage current at rated voltage. Then, both specimens are applied current lightning impulses at 200% of rated discharge current (10 kA) and the temperature is measured after. The lightning current impulse is 8/20 µs waveform and the duration between each impulse is 10s. Prior to the application of multiple current impulses, the difference of resistive current peak amplitude of specimen 1 and 2 were 3% and 0.95% respectively. Following positive current lightning impulses, the value changed to be 71.245% and 72.75% respectively. The specimens were then left to cool down in the room temperature for 1 day. After application of negative current lighting impulses, difference of resistive leakage current of specimen 2 changed to be 1.99%, and specimen 1 broke down after 2 impulses. Asymmetrical leakage current phenomena caused by the impulse current may negatively affect the breakdown characteristic of the SA which should be relevant with the collected charge inside the SA material, however, the opposite polarity of the applied impulse currents may eliminate such problem. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dielectric Response Analysis on Artificial ZnO Surge Arrester Degradation Using Polarization and Depolarization Current Based Method(2024-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The Effect of Electrical and Moisture Degradation of Metal Oxide Varistor with Insulation Diagnosis(2020-10-25); Condition based monitoring of surge arresters (SA) has become a primary concern to ensure power supply quality on medium and high voltage networks. Understanding of SA behavior helps forecast their failure. This paper presents the analysis of dielectric response and conductivity of Metal Oxide Varistor (MOV) under degradation factors (normal ageing, impulse ageing and moisture ageing) using Polarization and Depolarization techniques. Normal ageing is represented by stressing the MOV with 115°C temperature. For impulse ageing, 20, 40 ,60 and 100 shots of positive and negative polarity of standard lightning impulses current were applied. Moisture ageing was performed by soaking MOV under 115°C temperature for 12 hours representing wet condition and the soaked blocks were left at room temperature for 24 hours representing dry condition. Polarization and Depolarization Current (PDC) was measured after each ageing step. Resistivity, conductivity and polarization index were interpreted for insulation diagnosis. The experiments were taken on the MOV with rated voltage 3 kV and 5kA-nominal discharge. The importance of nondestructive electrical diagnostics based on polarization methods is validated by test results and is highlighted in detail in this paper. Finally, the results of different ageing factors were compared and discussed. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Experiences in nonconventional partial discharge measurement for gas-insulated substation in Thailand(2020-01-01);