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Experiment of Dielectric Frequency Response for Aged ZnO Surge Arrester
(2025-01-01)
Aiamrungruang, Phitthaya
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Methavithit, Winai
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Pannil, Pittaya
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Chuayin, Chaitawat
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Zinck, Matthieu
Condition-based monitoring of surge arresters has gained increasing attention in modern power system asset management, especially for medium-voltage equipment. This paper presents an investigation into the dielectric frequency response (DFR) analysis technique as a diagnostic method to evaluate aging and unhealthy conditions in 21-kV metal oxide surge arresters (MOSA). Four types of simulated defects, excessive number of lightning current stress, cracking, moisture ingress, and tracking, were introduced to represent common field failures. The DFR technique enables frequencydomain interpretation of dielectric properties, providing insight into insulation behavior over a wide frequency range. The test results show a significant variation in capacitance and dissipation factor corresponding to different defect types. Among these, moisture ingress exhibited the most severe deterioration. The findings suggest that DFR is a viable offline diagnostic method that can support preventive maintenance strategies for high-voltage surge arresters.
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Design and Experimental Verification of an Integrated Boost-Flyback Converter with Voltage Multiplier
(2024-01-01)
Tattiwong, Kaweewat
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Sopin, Anan
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Poungnoiy, Saisunee
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Kalnaowakul, Phuri
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Singhata, Napassadol
This paper introduces the design and experimental validation of an integrated boost-flyback converter with a voltage multiplier (IBFCVM). It describes the operation of the IBFCVM and provides its essential voltage and current equations. A phototyped circuit design for a 72W, 12V-to-120V IBFCVM is presented. Experimental results demonstrate that the proposed IBFCVM exhibits effective output voltage regulation, achieving an impressive efficiency of 89.9%.
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UWB Transmission Waveform Application for in an Indoor Localization System
(2024-01-01)
Mankong, Thanadon
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Promwong, Sathaporn
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Bunlaksananusorn, Chanin
Nowadays, the indoor localization systems had been widely utilized. The popular use of localization system is the global position system (GPS). However, the system fails in particular environments such as indoors because low received signal power. It is not appropriate to take a position. The indoor localization system was used to assist in finding a position in an indoor environment. There are several techniques used to evaluate. Technique trilateration model is a technique of geometric. This technique leverages circular intersections to estimate target positions. The circles are derived from a set of reference positions. This paper studies on indoor positioning in line of sight (LOS) using by IEEE 802.15.4 standard in ultra wideband option which this study employs trilateration to estimate the position of target objects. Biconical antennas with vertical polarization serve as both transmitting and receiving elements. The evaluation is conducted using a vector network analyzer (VNA) across a frequency range of 3GHz to 11GHz. The positioning accuracy will be assessed in terms of distance error.
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A Study of Low Band UWB Localization with Wooden and Metal Bookshelves Based on Measurement Data
(2024-01-01)
Mankong, Thanadon
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Promwong, Sathaporn
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Bunlaksananusorn, Chanin
This paper considers the potential of Impulse-Radio Ultra-Wideband (IR-UWB) technology which can be a barcodes replacement in bookshelf management systems. To assess its feasibility, we analyze IR-UWB propagation characteristics within bookshelf environments, particularly focusing on the impact of wooden and metal structures. A measurement-based evaluation scheme is employed, utilizing a vector network analyzer (VNA) alongside microstrip patch antennas for both the transmitter (Tx) and receiver (Rx) operating within a frequency range of 3.2GHz to 4.8GHz. The path loss, received signal strength (RSS), and cumulative distribution function (CDF) of the measured data are then analyzed to evaluate the suitability of IR-UWB for bookshelf management applications. These findings will inform the design of IR-UWB antennas and the overall assessment of this technology in this specific context
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Investigation of Leakage Current Behavior Based on Current Symmetry Due to Multiple Positive and Negative Impulses
(2024-01-01)
Chuayin, Chaitawat
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Pattanadech, Norasage
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Zinck, Matthieu
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Suksagoolpanya, Suthat
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Sontayananon, Nattawittayawud
The failure of Metal Oxide Surge Arrester becomes a major issue of the utilities. A strategy which is commonly utilized to diagnosis the problems is leakage current measurement in any terms of current e.g., total leakage current, resistive leakage current, capacitive leakage current. This paper aims to study the symmetrical behavior of the leakage current caused by positive and negative multiple lightning currents. The asymmetrical leakage currents were observed with 24 kV, 10kA commercial surge arrester which divided in to 2 groups. The experiment was conducted by measuring the leakage current at rated voltage and 1-mA reference voltage before applying a prepare of 5 shots of 10-kA positive and negative standard impulse current (8/20 μs) to groups I and II individually. After that, more 5 shots were applied to the specimens once more. The resistive leakage current at rated voltage and 1-mA reference voltage measurement were then performed after each impulse current application. Hence, groups I and II were applied with 15-shots multiple negative and positive impulse current respectively. The resistive leakage current at rated voltage and 1-mA reference voltage were performed after each 5 shots of impulse current. The experiment results show that (1) applying multiple impulse currents will make the asymmetrical leakage current. (2) positive polarity multiple impulse current creates asymmetry more than negative polarity. (3) negative polarity will increase the positive peak of leakage current and vice versa for positive polarity.
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The Experiment of VLF Tanδ on Service-aged MV Underground Cable
(2024-01-01)
Tangthanam, Worasak
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Bunlaksananusorn, Chanin
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Suksawat, Dusit
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Udomluksananon, Patt
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Jeenmuang, Siwakorn
This paper presents the service-aged MV underground cable experiment using very low frequency (VLF) testing. The underground cables in this experiment have been utilized in service for more than 10 years and subjected to TEAM stresses, particularly with moisture, throughout the service time. So, the effect of moisture leads these cables to bad condition. The cables under the experiments are both service-aged and unaged. These cables were prepared the same by peeling both end sides of the cables and were terminated with high voltage insulating tape. The VLF test combined with the tangent delta (tanδ) measurement, according to IEEE Std. 400.2-2013 was performed to assess the condition of these cables and compare them with the unaged cable. The test results revealed that according to IEEE standard 400.2-2013, the service-aged underground cables were assessed in Action Required criteria. Still, the unaged underground cable was assessed in the Further Study Required criteria. Moreover, the tanδ values from service-aged underground cables have significant differences, with service-aged underground cables having higher values than unaged cables. Besides, the variation of tanδ data samples at each test voltage level from some underground cables shows a decreasing trend at 1.0U0 and 1.5U0. Nevertheless, the test voltage at 0.5U0 shows the constant trend of tanδ samples. This analyzed result can indicate that the insulation condition has humidity inside the cable insulation.
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The Behavior of Dissolved Gas in Mineral Oil with TiO2 and Three Types of Insulation Paper at 150 Degree Celsius
(2024-01-01)
Jongvilaikasem, Korraya
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Bunlaksananusorn, Chanin
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Vittayakorn, Wanwilai
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Pattanadech, Norasage
The main electrical insulation in oil-immersed transformers is liquid insulation and paper insulation. Liquid insulation is generally used mineral oil. However, improvements in the quality of liquid insulation are continually being made for better efficiency i.e. adding various additives such as inhibitors and nanoparticles. Nanoparticles are a solid substance used in research for many years. TiO<inf>2</inf> is a type of nano that is commonly used in research to increase the efficiency of mineral oil. This research experimented by preparing dry transformer oil mixed with 0.03% TiO<inf>2</inf>. The test vessels consisted of 3 main components: 1) 35 ml of MO with 0.03% TiO<inf>2</inf>, 2) 1 gram of paper with three types of insulation including pressboard, kraft, and diamond dot paper, and 3) two types of coils including copper and aluminum with size 1∗2.5 cm. The sample vessels were aged at 150 C for 72 hours in the vacuum oven. After aging, oil samples were analyzed by dissolved gas analysis (DGA). From the DGA test results, it was found that similar weights of different types of paper produced different gas-generating results.
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The Time Domain Dielectric Response of 138 kV and 550 kV OIP Bushing
(2024-01-01)
Yamsiri, Thummanoon
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Bunlaksananusorn, Chanin
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Suksawat, Dusit
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Rojanasunan, Warisanan
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Jeenmuang, Siwakorn
In this paper the dielectric response in time domain which is polarization and depolarization current (PDC) measurement is applied to assess the global condition of OIP bushings. The bushings in this paper are five 138 kV OIP bushings and three 550 kV OIP bushings which are out of service already. From the PDC results, capacitance and current trends of both voltage levels were investigated individually. PDC results in this paper can be useful data for further analysis and diagnostic.
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Investigation of Dielectric Response in a 22/0.4 kV Distribution Transformer: Effects of Moisture Content
(2024-01-01)
Daengdee, Danaiwat
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Bunlaksananusorn, Chanin
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Suksawat, Dusit
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Chumpiboon, Komin
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Jeenmuang, Siwakorn
Transformers play a crucial role in power systems, ensuring efficient energy transmission and distribution. This research focuses on a 22/0.4 kV transformer decommissioned after over 20 years of service. The study involves draining the transformer oil completely and refilling it with oil characterized by known moisture content and breakdown voltage levels until reaching normal operating conditions. The objective is to study the effects of increased moisture content on the dielectric response within the actual structure of the transformer. Diagnostic measurement techniques, including Frequency Domain Spectroscopy (FDS) and Polarization Depolarization Current (PDC), are utilized to evaluate the insulation condition of the transformer. FDS provides information on the dielectric response over a wide frequency range, while PDC assesses the polarization and depolarization behavior of the insulation material. These techniques offer valuable information on the ageing and moisture content of the insulation. The experimental results will be presented and discussed in this paper.
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The Behavior of Dissolved Gas in Difference Liquid Insulation With ZnO Under Thermal Ageing Condition
(2024-01-01)
Jongvilaikasem, Korraya
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Bunlaksananusorn, Chanin
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Vittayakorn, Wanwilai
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Pattanadech, Norasage
Mineral oil is a commercial product that has been widely used as a dielectric liquid in transformers. However, alternative liquids have been developed to gradually replace mineral oil because of some better liquid insulating properties in the point of safety aspect and environmentally friendly. This paper represented the behavior of Dissolved Gas in different types of liquid insulations mixed with nanoparticles under thermal aging conditions. Various types of liquid insulation including mineral oil, natural ester, and palm oil added with a 0.03% concentration of zinc oxide (ZnO) and sorbitan mono-oleate surfactant (Span 80) underwent thermal stress aging at 90, 110, 130, and 150 degrees Celsius with 200 mbar for 72 hours in a vacuum oven. Then, the concentration of dissolved gas in the stressed samples was investigated by the Dissolved Gas Analysis (DGA) technique. From the test results, it was discovered that distinct liquid insulations and aging temperatures produced diverse dissolved gas generation behaviors. Besides, the dielectric liquid with Nanofluids or Nanofluids mixed with span 80 seems to have no different dissolved gas generation behaviors.

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