Pattanadech, Norasage

Preferred name

Alternative Name

Pattanadech, N.

Main Affiliation

School of Engineering

norasage.pa@kmitl.ac.th

Now showing 1 - 10 of 69

Some of the metrics are blocked by your
consent settings
Comparison of Voltage-time to Surface Failure of Various Insulation Material for Space Aerial Cables
(2016-01-01)
Krirapee, Sathit
;
Potivejkul, Siriwat
;
Pattanadech, Norasage
This paper aims to represents the investigation of surface tracking resistance of various types of cable insulations. Five kinds of cable material i.e. non carbon filled crosslink polyethylene (XLPE), carbon filled XLPE, low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE) were examined. The test specimen has a dimension of 10 mm in width, 50.8 mm in length and 1.52 mm in thickness. The test samples were classified into two groups for investigation. The former group was the new test samples, whereas the latter test samples were stressed by thermal ageing with 120<sup>o</sup>C for 168 hours. Then both specimens were examined. One side of the specimen was contacted with high voltage electrode terminal made of 1 mm diameter Nichrome wire. Another side of the test specimen was dipped into 0.1 percent solution of ammonium chloride as grounded electrode. The spacing between electrodes at dry area was determined for 25.4 mm. After completion of the test set up, AC high voltage was applied to the test specimen. The dip rate of the specimen into the solution was set up as 4 times per minute. The test voltage level was in the range of 1-3.5 kV. The experiment was performed in accordance with ICEA S-66-524 (Method B). The test voltage was applied to the test specimen until the insulation failure could be observed. Then, the insulation failure voltage and failure time were recorded. The test results illustrated that both unaged and aged HDPE and non carbon filled XLPE provided the higher surface tracking resistance than carbon filled XLPE, LDPE and MDPE respectively. Besides, the thermal stress aging had not much effect on the surface tracking resistance characteristic of tested material. It can be summarized that the material structure much more influenced the surface tracking characteristic of the cable material.
Some of the metrics are blocked by your
consent settings
Polarization and depolarization current characteristics of thermally stressed stator bars
(2019-07-01)
Pattanadech, N.
;
Srichuen, N.
;
Wang, C.
;
Kaewdee, N.
;
Poungpat, T.
Polarization and depolarization current (PDC) measurement was used in this research to investigate the insulation integrity of stator bars. This method is non-destructive testing. This paper presents the PDC analysis of thermally stressed stator bars divided into two main groups. The first group was heated at 100^{\circ}C and the second group was heated at 130 ^{\circ}C for 36 hours. After 12, 24 and 36 hours of heating process, PDC measurement of each test specimen was performed. PDC test results including capacitance ratio and dielectric dissipation factor were analyzed and reported.
Some of the metrics are blocked by your
consent settings
Generalized regression networks for partial discharge classification
(2016-01-18)
Pattanadech, N.
;
Nimsanong, P.
;
Potivejkul, S.
;
Yuthagowith, P.
;
Polmai, S.
This document represents a partial discharge (PD) classification by using Generalized Regression Networks (GRNN) model. Two PD classification models, GRNN1 with 11 input variables and GRNN2 with 3 selected derived statistic parameters, were investigated for classification of PD signals into 5 patterns, corona at high voltage side in air, corona at low voltage side in air, corona at high voltage side in mineral oil, corona at low voltage side in mineral oil and surface discharge in mineral oil. The conventional PD measurement was performed for measuring PD signals of the artificial PD models. The statistical parameters of the PD signals such as skewness, kurtosis, asymmetry, cross correlation and so on were calculated from the developed computer program. Then, 60% of the experimented data was used as a training data for the developed PD classification models. Another 40% experimented data was used to evaluate the performance of the designed PD classification models. It was found that the GRNN1 model can classify PD patterns better than GRNN2 model. The accuracy for PD classification of GRNN1 model was 100% while the accuracy of GRNN2 model was 97.5% of 40 testing data.
Some of the metrics are blocked by your
consent settings
Dielectric breakdown strength of mineral oil based nanofluids
(2016-11-28)
Muangpratoom, Pichai
;
Pattanadech, Norasage
In this paper, the dielectric properties of the mineral oil-based nanofluids was studied. The aim of this research is to improve electrical property of the mineral oil by applying nanotechnology knowledge. Three types of nanoparticle i.e. Titanium dioxide (TiO<inf>2</inf>), Barium titanate (BaTiO<inf>3</inf>) and Zinc oxide (ZnO) with the mean diameter less than 100 nm were used in the experiment. The nanofluid samples, the mineral oil mixed with nanoparticle, were prepared in three processes. Firstly, the mineral oil was mixed with 0.01% of nanoparticle volume fraction of nanoparticle. Besides, the mineral oil was also mixed with 0.03% of nanoparticle volume fraction. Then it was dispersed by using a magnetic stirrer. Finally, the ultrasonic dispersant technique was applied for the prepared nanofluids to ensure the homogeneity of such liquid. To measure the AC breakdown voltages, an oil breakdown tester (FOSTER OTS 60AF) was used. The gap distance between electrodes was set to be 2.5 mm. The testing was carried out 6 times for each liquid test sample according to IEC 60156. The test results showed that the AC breakdown property of the modified liquid was strongly influenced by the type of the nanoparticles added. With the addition of nanoparticles, the AC breakdown voltage increased slightly above that of the mineral oil (37 kV). In case of 0.01% nanoparticle volume fraction, the AC breakdown voltage of the mineral oil with TiO<inf>2</inf>, the mineral oil with BaTiO<inf>3</inf> and the mineral oil with ZnO was 42 kV, 45 kV and 46 kV respectively. For 0.03% nanoparticle volume fraction, the AC breakdown voltage of the mineral oil with TiO<inf>2</inf>, the mineral oil with BaTiO<inf>3</inf> and the mineral oil with ZnO was 45 kV, 48 kV and 60 kV respectively. From these results, it is indicated that nanoparticles is a good candidate to develop mineral oil-based nanofluids for dielectric applications.
Some of the metrics are blocked by your
consent settings
Effect of contaminant on breakdown characteristics of mineral oil and commercial natural ester
(2018-07-02)
Maneerot, S.
;
Pattanadech, N.
This research paper presents the results of an investigation into the effect produced by the addition of various contaminant particles at various temperatures on the 50 Hz AC breakdown voltage of mineral oil and natural ester. The test cell apparatus employed mush room-shaped electrodes according to IEC 60156 and the various liquid samples which were prepared for the tests contained various combinations of the following: a) three different contaminant particles (cellulose, spherical iron and copper) of approximately 20 µm diameter, b) three different concentrations of contaminant particles (0.001% m/V, 0.003% m/V and 0.005% m/V) and c) four different temperatures for the test cell liquids (25°C, 50°C, 70°C, and 90°C). The test results show that the presence of the added particles in the tested dielectric liquids resulted in a reduction of breakdown voltage, with the 4 major determinants of the reduction being a) change in particle type, b) change in particle concentration, c) change in liquid type, and d) change in liquid temperature. The most important findings from the testing and analysis conducted are as follows: 1) higher contaminant concentrations resulted in lower breakdown voltages, 2) the addition of copper particles had the most significant effect on reducing breakdown strength, and 3) that the largest decrease in breakdown strength was recorded during testing of the contaminated mineral oil test samples and the FR 3mineral oil test samples at 70°C.
Some of the metrics are blocked by your
consent settings
Improved Least-Square Prony Analysis Technique for Parameter Evaluation of Lightning ImpulseVoltage and Current
(2016-02-01)
Yutthagowith, P.
;
Pattanadech, N.
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 your
consent settings
New current-voltage transferring device with different metals
(2015-09-01)
Kando, Masaaki
;
Pattanadech, Norasage
A new concept of an electrical shunt with different materials (aluminum and copper) has been developed to be used as an alternative current measurement device. The device provides better current measurement characteristics compared with the conventional current measurement devices such as a shunt resistor with an ammeter or the multiple shunts consisting of molybdenum having a low temperature coefficient and a Rogowski coil with an integrated circuit. The currents in several electrical circuits have been measured using the developed current-voltage transferring device (CVTD) as voltages between the aluminum and copper elements. The measured voltages (V<inf>m</inf>) are proportional to measuring currents (I<inf>m</inf>), which is shown as the following the experimental equation V<inf>m</inf> [mV] =kI<inf>m</inf> [A], in which k is a coefficient depending on the configuration of the CVTD.
Some of the metrics are blocked by your
consent settings
The Dissipation Factor (tan δ) Monitoring of A Stator Winding Insulation of A Synchronous Machine
(2018-11-14)
Phloymuk, N.
;
Nimsanong, P.
;
Phumipunepon, N.
;
Potivejkul, S.
;
Wiangtong, T.
the aim of this paper is to describe the dielectric loss tangent (tan δ) behaviors of the stator winding insulation of the 14.5 MVA 11kV synchronous machine from 2014-2017. This machine is still operated up to now. The tan δ values at different test voltages was measured and recorded. It was found that the sharp increase in tan δ values gave the sign of a significant degree of contamination and damage on the insulation surface which was proved by inspection. From the investigation the tan δ measurements is one of the effective ways to monitor and evaluate the insulation conditions of the stator insulation. The analysis and discussion of the existed problem of the synchronous machine are also included in this paper.
Some of the metrics are blocked by your
consent settings
Condition assessment of MV motor based on charge difference and charge ratio analysis
(2019-07-01)
Nimsanong, P.
;
Boonsaner, N.
;
Pattanadech, N.
Insulation resistance and polarization index tests have been conducted in utility companies as one of the major tools for evaluating the integrity of stator winding insulation of medium voltage motor. Unfortunately, the information obtained from the measurement results are the combination of the electrical problem and polarization problem in the insulation system not separated from each other. This paper presents a new approach so-called charge difference analysis (QDA) and charge ratio analysis (QRA) to identify the problem in stator winding insulation occurred from conduction mechanism or/and polarization mechanism. Moreover, proposed parameters which are QD, QG and QR have been conducted on field motors in the following case studies: The first group (A) consists of two motors of which one is new motor and the other one is severely aged motor, the second group (B) consists of two motors of which one is lightly loaded motor and the other one is thermally aged motor, and the third group (C) consists of a single motor, on which PDC measurements have been carried out after maintenance in 2014 and 2016 respectively. From experiments, it was found that proposed parameters are able to provide useful information about the condition of stator insulation, i.e. contamination or/and degradation.
Some of the metrics are blocked by your
consent settings
Polarization and Depolarization Current Measurement for Foreign Object Detection in Gas-Insulated Transmission Line
(2019-10-01)
Nganpitak, Tritod
;
Chancharoensook, Phop
;
Pattanadech, Norasage
Polarization and depolarization current (PDC) test is one of non-destructive insulation test method that usually uses for diagnosis the solid and liquid insulation problems. In case of gas-insulated transmission line (GIL), it not only comprises of gas insulation but also the solid insulation such as cone insulators. This paper presents the PDC measurement for foreign object detection in GIL. A 230kV, 2500A, single phase GIL with 2 m length was used in the PDC experiments. The external diameter of this GIL conductor and enclosure are 92 and 366 mm respectively. In the experiment, defects on the cone insulator was simulated in three cases, i.e. 1) cone insulator was attached with a paper tape, 2) cone insulator was attached with an aluminum foil, 3) cone insulator was attached with a moist paper. The width of the simulation defect was approximately 2 mm. The lengths of the simulation defects were varied from 25 - 200 mm depending on defect types. PDC test results obtained from the GIL with the simulated defect cone insulators were compared with that of clean and dry cone insulator as reference. The results of the experiments showed that PDC curves obtained from GIL with the simulated defect cone insulators were clearly different from that of the reference case. Other analyses are reported in the paper.

Pattanadech, Norasage

Filters

Settings

Sort By

Results per page