- 标题
- 摘要
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- 实验方案
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[IEEE 2018 IEEE 7th International Conference on Photonics (ICP) - Langkawi, Malaysia (2018.4.9-2018.4.11)] 2018 IEEE 7th International Conference on Photonics (ICP) - Detection of Power Transformer Fault Conditions using Optical Characteristics of Transformer Oil
摘要： Power transformers are important in the power transmission and distribution network. A continuous monitoring of the transformer is important in ensuring the prolonged service of the transformer. This paper focuses on the characterization of transformer oil using optical detection method. 10 Transformer oil samples from the main tanks and 11 oil samples from the on-load-tap-changer (OLTC) were obtained for the optical characterization from 200 to 3300 nm. Based on the conventional results interpretation using dissolved gas analysis (DGA) and Duval Triangle, the optical characteristics of the samples in 2120 to 2220 nm clearly demonstrate the detection of electrical discharges of high energy (D2), electrical discharges of low energy (D1) and thermal faults at temperatures above 700°C (T3) faults. This approach provides a quicker and cheaper method to determine the condition of power transformers based on the optical characteristics of transformer oil.
关键词： spectrophotometer,On-load-tap-changer,main transformer tank,transformer oil aging
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - High Voltage CT Ratio Errors Dependency on Voltage and Power Factor of the Metered Load
摘要： This paper describes the results of the performance evaluation of the ratio errors of a high-voltage current transformer (CT) and a high-voltage combined current and voltage transformer (CTVT) under different operating conditions. The ratio errors of the CT and CTVT are measured at different power factors of the primary and secondary windings in which the CT (or part of the CTVT) is operated at high voltages. The results show that the ratio error of the CT is significantly different at different power factors, and the effects of the power factor on the ratio error of the CTVT are also significant. The measurement results are compared with the theoretical calculations, and the differences between them are discussed.
关键词： ratio errors,Current transformer,voltage transformer,load
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Calibration of Electronic Transformer Tester Using Digital Sampling Method
摘要： A reference system for the calibration of electronic transformer tester based on the digital sampling method is described. The calibration software is designed in conformity to the IEC 61850-9-2/LE standard. The extended uncertainties estimation to the current function of the electronic transformer testers are 5.4E-5 for magnitude and 64μrad for phase displacement with coverage factor k=2. Corresponding to the voltage function, the extended uncertainties are estimated to within 2.2E-5 and 50μrad separately.
关键词： IEC61850-9-2,electronic transformer tester calibration,electronic transformer tester,digital sampling
更新于2025-09-10 09:29:36
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Terahertz Time Domain Spectroscopy of Transformer Insulation Paper after Thermal Aging Intervals
摘要： An accelerated thermal aging process was used to simulate the condition of paper insulation in transformer oil-paper systems. Optical parameters of the insulation paper after various aging intervals were analyzed with terahertz time-domain spectroscopy (THz-TDS) over the range 0.1~ 1.8 THz. The result shows that the paper had seven absorption peaks at 0.19, 0.49, 0.82, 1.19, 1.43, 1.53, and 1.74 THz, and density functional theory of B3LYP/6-311G+ (d, p) was used to simulate the molecular dynamics of the repeating component (cellobiose) of the cellulose paper. Theoretical spectra were consistent with experiment, which had absorption peaks at 0.18, 0.82, 1.47, and 1.53 THz in the same frequency range. At the same time, the paper samples after various aging intervals had different refractive indexes, and least squares ?tting revealed a linear relationship between the degree of polymerization and the refractive index of the paper. Hence, this paper demonstrates that THz-TDS could be used to analyze the aging condition of transformer insulation paper and provides the theoretical and experimental basis for detection.
关键词： transformer insulation paper,novel diagnostic technique,molecular dynamics simulation,DFT,terahertz-time-domain spectroscopy
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - A Simultaneously Comparison of Three Current Transformer Calibration Systems
摘要： This paper shows a novel method for simultaneous comparison of three current transformer calibration systems at power frequency. All three systems are designed for the calibration of high accuracy current transformers. The measuring method is also suitable for inter-laboratory comparisons of calibration systems/methods. The paper gives a description of the novel measuring method and the compared measuring systems. The comparison results are shown and discussed.
关键词： calibration,current comparator,AC current measurement,uncertainty of measurement,current transformer
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Accurate High Direct Current Measurements for Industry
摘要： Calibration of high dc current transformers, dc ammeters, and dc current range extenders can be carried out simply using a high quality dc current transformer, an uncalibrated high current source and a calibrated low current source. The method, called the Current Reference Step Method, utilizes a buildup technique that exploits the ability that a dc current transformer possesses to accurately sum the currents linearity. its window with excellent differential through. Uncertainties of several parts per million in the applied high current can be achieved.
关键词： dc current transformer,Calibration,dc current and resistance measurement,dc current ratio
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - A New Method to Extend the Current Ranges from 10mA to 100 A at Frequencies up to 100 kHz
摘要： A new method to extend the current ranges from 10 mA to 100 A at frequencies from 50 Hz to 100 kHz has been described. This method is based on the use of a binary inductive current divider and a set of current transformers to cover the current ranges from 10 mA to 100 A. A 1-? shunt of coaxial design has been developed as the time constant standard with known ac-dc difference. The current level dependence of current transformers with ratios of 10:1 and 100:1 and shunts has also been evaluated.
关键词： Binary inductive current divider,step-up procedure,current shunt,current transformer,level dependence
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Precision Characterisation of Current Transformers and Shunts in the Audio Frequency Range
摘要： This paper presents a technique to compare two current transformers, or a current transformer and ac current shunts, with an uncertainty better than 1 μA/A and 1 μrad at audio frequencies. Examples of such a comparison at frequencies from 10 Hz to 10 kHz are given. Due to its low uncertainty, the described technique made it possible to accurately measure critical parameters such as common-mode dependence of a current transformer and impedance variation of current shunts with ac current applied.
关键词： AC current,measurement,current transformer,current shunt
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - An AC Four-Terminal Low Value Resistance Bridge
摘要： This paper describes a current transformer based ac four-terminal low value resistance measurement bridge. The design and performance of this bridge is presented, which compares resistors from 10 to 0.1 ohm over a frequency range of 100 Hz-10 kHz. The reference ratio arm used in this bridge is a special designed high accurate zero-flux current transformer (ZFCT). The current ratio value of the ZFCT is self-calibrated by using the conventional build up method. An auxiliary current transformer combined with variable impedance is used to constitute the wagner circuit.
关键词： zero-flux current transformer,ac bridge,resistance measurement,Measurement
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Calibration of the Absolute Linearity of Lock-in Amplifiers
摘要： This paper describes the development of a system capable to calibrate the linearity of lock-in amplifiers in their 1 μV range for frequencies between 20 Hz and 1 kHz. This system is based on cascaded inductive voltage dividers (IVD). These dividers have been especially designed to maximize their input impedance and to have minimal influence on the previous stage. The cascaded topology of this system reduces the uncertainty for very large ratios (> 1000:1) and reaches measurement uncertainties below 1 nV at 10 μV.
关键词： lock-in amplifier,synchronous sampling,voltage ratio,very low AC voltage,IVD,Linearity,transformer
更新于2025-09-10 09:29:36