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Partial Discharge Localization Model in Power Transformer with Fingerprinting Technique
(2023-01-01)
Chaisang, Aditep
;
Tiengthong, Thanadol
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Maw, Myo Myint
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Promwong, Sathaporn
Partial discharge localization in power transformers is of utmost importance, requiring an effective evaluation method to identify the location of such events precisely. Antenna placement poses challenges within power transformers, as improper positioning can significantly affect localization precision. This paper introduces an evaluation of the fingerprinting method for ultra-high frequency partial discharge localization. The fingerprinting method, commonly employed in wireless localization systems, is utilized to assess the accuracy of partial discharge localization. The proposed method leverages fingerprinting analysis and received signal strength to evaluate partial discharge events in power transformers. Experimental partial discharge measurements are conducted on a power transformer model provided by Tesla Power Company. The results include the average received signal strength at each measurement position and the distance error of the partial discharge location determined using the fingerprinting method. This research contributes to assessing partial discharge in power transformers, offering valuable insights for enhancing their health and performance evaluation.
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Evaluation of UHF transfer function in a power transformer for real-time partial discharge detection
(2020-08-14)
Promwong, Sathaporn
;
Tiengthong, Thanadol
The UHF transfer function is significant for a short-range communication system, e.g., a real-time diagnosis of partial discharge (PD). Real-time diagnosis of the PD has become a challenging topic of improving the diagnosis of high voltage equipment, including a power transformer. Further, the PD detection in high voltage equipment is critical since the PD can cause severe damage to electrical systems. The PD detection methods are classified by a phenomenon of the PD. The PD detection by electromagnetic (EM) method is regulated by IEC TS 62478, which specified the UHF band for the PD detection in power transformers. Hence, an evaluation of frequency characteristics is essential to achieve an excellent diagnostic performance. In this paper, a complex form of channel analysis is applied with the PD detection method. The measurement model in a power transformer is proposed. The optimum receiver is introduced to maximize SNR and hence it is easy to analyze the results. The results were analyzed by using magnitude, phase, group delay, received waveform, and path loss parameters. The results show that the measured channel is affected by the structure of the power transformer. The contribution of this research is useful for improving the precision of the PD detection with EM method and building an accurate real-time partial diagnosis via a smartphone or laptop computer.
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A UHF compact complex impedance-transforming balun with high isolation
(2020-01-01)
Nithiporndecha, Kittipong
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Pakasiri, Chatrpol
Background: A compact complex impedance-transforming balun for UHF frequencies, which is based on a coupled-line structure that matched all ports and provided high output port iso-lation, was designed in this paper. Methods: A lumped component transformation was used to minimize circuit size. The implemented circuit operated at 433 MHz with the reflection coefficients less than-16 dB at all ports, 0.22 dB amplitude balance and 180° phase balance at the output ports. The signal coupling between the output ports was-16.8 dB. The circuit size is small at 0.032λ. Results: Complex impedance-transforming baluns were designed to operate at 433 MHz. The source impedance at port 1 was set at Z<inf>s</inf> = 12-j12Ω and the load impedances at port 2 and 3 were set at Z<inf>L</inf> = 80 + j30Ω. Conclusion: A compact complex impedance-transforming balun at UHF frequency, with all ports matched and high isolations, was designed and illustrated in this paper.
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Evaluation of partial discharge localization in power transformer with weighted centroid method
(2019-07-01)
Tiengthong, Thanadol
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Sanguanpuak, Chanidaphar
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Southisombat, Khamphoui
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Promwong, Sathaporn
Partial discharge localization in power transformer is very important. A suitable evaluation method is one of the most critical part in order to find the exactly location of partial discharge. In this paper, an ultra-high frequency partial discharge localization is introduced. Weighted centroid method is one of a suitable method to evaluate the localization in partial discharge localization as well as other wireless localization system. There are many limitation of place to install the antenna in power transformer. The proper antenna placing is very important issue because improper location will affect the accuracy of partial discharge localization. The experiment of partial discharge measurement is carried out on a power transformer model from tesla power company. The purposed method used weighted centroid with received signal strength to evaluation the partial discharge in power transformer. The results show average value of received signal strength at each measurement position and the distance error of partial discharge location with weighted centroid method. The benefits of this method is useful to evaluate the partial discharge in power transformer.
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A compact UHF dual-band rat-race coupler with complex impedance load
(2018-10-01)
Pakasiri, Chatrpol
;
Wang, Sen
A compact UHF dual-band rat-race coupler with complex terminated loads is proposed. The design procedure starts with design circuit with transmission line (TL) components, and design equations are also detailed in this letter for dual-band operation. Moreover, the circuit size is further reduced by replacing the TLs with lumped components. An example circuit operating at 450/900 MHz is given. The measurement shows that the circuit has the reflection coefficient at the input port less than −13 dB, the transmission coefficient greater than −5.6 dB and phase difference less than ±10° at the output ports.
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Impedance effect of elliptical curved surface on RFID tag performances
(2017-12-19)
Suwalak, Rattapong
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Phongcharoenpanich, Chuwong
This paper presents the effect of the impedance curved surface to the characteristics of the RFID tag. The proposed passive RFID tag is placed on the elliptical curved surface. From the simulation result, it this found that the proposed RFID tag has a flat gain in the UHF RFID frequency band in Thailand. Moreover, the variation of the length and width of the elliptical surface is important effect on the input reactance of the RFID tag.
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Circularly polarized UHF-RFID antenna using defected rectangular plate on the ground plane
(2012-11-26)
Phongcharoenpanich, Chuwong
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Dentri, Sitthichai
This paper presents a UHF-RFID reader antenna radiating circular polarization with unidirectional pattern. The antenna structure consists of two plates. The upper plate acted as radiating element contains notched rectangular plate, rectangular aperture and slot line. The lower plate is the ground plane. The parametric study is carried out to achieve the frequency response of 920-925 MHz according to Thailand standard of UHF-RFID system. The prototype antenna was fabricated and measured. The simulated half-power beamwidth (HPBW) in E- and H-planes are 65 and 68 degree, respectively. The measured HPBW in both planes is identical to 55 degree. The simulated and measured bandwidths are 7.26% and 10.7%, respectively. The simulated and measured axial ratios at 922.5 MHz are 0.64 dB and 0.09 dB, respectively. © 2012 IEEE.
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A circularly polarized square plate antenna with two inclined slots for UHF-RFID reader
(2011-12-01)
Charoenchue, Putuch
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Phongcharoenpanich, Chuwong
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Phaebua, Kittisak
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Aunchaleevarapan, Kraison
This paper presents a circularly polarized square plate antenna with two inclined slots excited by a probe on square ground plane to radiate circularly polarized unidirectional beam. This antenna is proposed for installing at the reader of Radio Frequency Identification (RFID) at Ultra High Frequency (UHF) band. UHF-RFID in Thailand has the bandwidth from 920 MHz to 925 MHz, and center frequency is 922.5 MHz. The proposed antenna structure is simple because of using the single probe to feed the antenna for circularly polarized radiation. The pattern of this antenna is unidirectional beam with gain 8.6 dBic and axial ratio of 0.92 dB at center frequency. The obtained measured bandwidth is 50 MHz. © 2011 IEEE.
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The study of disc monopole antenna for partial discharge measurement
(2007-12-01)
Petchphung, Prawit
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Leelajindakrairerk, Monthon
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Pattanadech, Norasage
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Yutthagowith, Pearawut
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Aunchaleevarapan, Kraision
This paper presents the study of disc monopole antenna for partial discharge measurement. The antenna was studied with computer program and tested. Then it was used for partial discharge measurement of the artificial partial discharge models, corona discharge, surface discharge, and internal discharge. The partial discharge tested results obtained from the designed antenna are relatively similar the tested results obtained from the standard antenna. The tested results show that the designed disc monopole antenna prototype has the good characteristics to measure partial discharge phenomena. It is still improving for high efficiency. © 2007 RPS.

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