KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Kitcharoen, P.

Search Results

Now showing 1 - 4 of 4
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Dielectric Properties of Resin Rich Stator Coil of High Voltage Motor during Processing
    (2018-11-14)
    Boonsathitthavorn, S.
    ;
    Phumipunepon, N.
    ;
    Kitcharoen, P.
    ;
    Pattanadech, N.
    One of the non-destructive test methods commonly used to characterize the electrical properties of power equipment is polarization and depolarization current testing. The objective of this paper is to study of the change of dielectric properties during the manufacturing stages of a stator coil used in 6.6 kV 260 kW motor. There were five steps to manufacture the resin rich stator coil. The first step, the copper coil was wound around by NOMEX paper. Then the slot portion of the stator coil was wound by KREMICAL tape as the second process and by the conductive tape as the third process. Then, the insulation and conductive layer of the stator coil were pressed and cured at 160°C for one and a half hour as the fourth process. The pressing and curing will combine the multi insulation to be homogeneous insulation of the stator coil. The final step, the end winding portion was wounded by Filosam tape and polyester tape. The polarization and depolarization currents were measured and recorded after finishing each manufacturing process. From the test results, the polarization currents and depolarization currents obtained from each step were clearly different. Then the polarization and depolarization currents, conduction current and capacitance of the test results were analyzed and reported in this paper.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Development of a low-pass filter for partial discharge testing system with the power frequency converter
    (2018-11-01)
    Prombud, T.
    ;
    Kitcharoen, P.
    ;
    Yutthagowith, P.
    The development of a low-pass filter for partial discharge test system that based on a power frequency converter is presented in this paper. The PD testing system is composed a 200-Hz power frequency converter and the designed filter connected with a high-voltage test transformer and a conventional partial discharge detection system. It is found that the power frequency converter acting as the low-voltage source always provides the high noise level with effecting to the background noise occur in the partial discharge test. Sometimes noise level is higher than the acceptable level of the PD tests in some high-voltage equipment such as potential transformers, distribution transformer, and so on. In this paper, the performances of the filters with different designs are studied and compared the result in terms of the output voltage difference (RMS, voltage , and ,peak,voltage 2), total harmonic distortion of the output high voltages value (THD<inf>v</inf>), and value of background noises as occur in the partial discharge test. The low-voltage source based on uni-polar pulse width modulation (PWM) topology was employed in the PD testing system. From the experimental results, the designed filter shows the promising performances with low levels of the background noise, THD<inf>v</inf>, and voltage difference. The experimental results show that the background noise is lower than 2.0 pC, the voltage difference and THD<inf>v</inf> are less than 5%. In addition, the designed filter has been tested in the partial test of a real potential transformer successfully.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Development of a partial discharge testing system for potential transformers
    (2018-04-27)
    Prombud, T.
    ;
    Kitcharoen, P.
    ;
    Yutthagowith, P.
    In this paper, the development of a partial discharge testing system for potential transformers (PTs) is presented. The system is composed of a low-voltage and 200-Hz power frequency converter connected with a low pass filter, a high-voltage transformer, and a conventional partial discharge detection system. The performances of the converter with three generated waveform, i.e. square wave, quasi-square wave, and unipolar pulse width modulation (PWM) are compared in terms of the DC charging voltage, the voltage difference (peak voltage/square root of 2 and rms voltage), total harmonic distortion of the output high voltage (THDv), and background noises in the partial discharge test. It is found that the unipolar PWM frequency converter provides the best performances in terms of the voltage difference, THDv, and background noise. The voltage difference and THDv are lower than 5%, and the background noise is less than 2.5 pC. In addition, the developed system has been used for the real partial test on a potential transformer in the distribution system successfully.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Dielectric properties of mineral oil compared with natural ester
    (2017-11-29)
    Jariyanurat, K.
    ;
    Nimsanong, P.
    ;
    Chaisiri, P.
    ;
    Maneerot, S.
    ;
    Kitcharoen, P.
    In this paper, dielectric properties of the mineral oil, ELECTROL A, and the natural ester, FR3, are comparatively investigated. AC breakdown voltages, dielectric dissipation factor, relative permittivity, partial discharge inception voltage and partial discharge of the mineral oil and of the natural ester are tested. In order to verify the capability in practical use of the mineral oil and the natural ester for transformer insulation systems, the impregnation of such liquids with pressboard insulation is performed. The impregnated pressboards are tested in the laboratory to measure the AC breakdown voltages. It is found that the natural ester shows superior dielectric properties to the mineral oil except the dielectric dissipation factor.