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- 摘要
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- 实验方案
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[IEEE 2018 2nd IEEE Conference on Energy Internet and Energy System Integration (EI2) - Beijing, China (2018.10.20-2018.10.22)] 2018 2nd IEEE Conference on Energy Internet and Energy System Integration (EI2) - Study on Fractal Butterfly Antenna Sensors Detecting Partial Discharge UHF Signal Propagating from GIS Placing Hole
摘要： Detecting the Ultra-High Frequency (UHF) electromagnetic wave has been acknowledged as an effective method in the measurement of varied kinds of partial discharges in Gas Insulated Switchgear (GIS). However, electromagnetic wave has been shielded completely owing to the steel flange around the insulator in recent years. Detecting the electromagnetic wave propagating from the placing hole in the steel flange becomes the only practicable method. The traditional sensors enter a bottleneck stage when they are used to detecting the electromagnetic wave propagating from the placing hole. The sensitivity declines a lot and output signal becomes weaker. At present, there are no relevant sensors, which detecting UHF electromagnetic wave propagating from placing hole. By adopting the fractal technology, back cavity and loaded resistor, the UHF sensor of fractal butterfly antenna was developed based on the software of High Frequency Structure Simulator(HFSS). Equivalent height was tested in the platform of Giga hertz Transverse Electromagnetic(GTEM) chamber. Detection sensibility and validity was professionally tested via applied in an experimental platform of 220kV GIS. It is concluded that the fractal butterfly antenna sensor belongs to the linear polarized antenna. The available frequency range is concentrated in 0.8-2GHz. The average equivalent height of fractal butterfly antenna is twice more than the traditional sensors. Detecting sensitivity of partial discharge is lower than 20pC.
关键词： placing hole,GIS,partial discharge,fractal butterfly antenna
更新于2025-09-23 15:23:52
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Spectrally-selective Photovoltaics via Photonic Band Engineering in Absorbing Media
摘要： Partial discharge (PD) detection has been proved as an effective tool for insulation condition monitoring of power equipment. The energy of PD pulses is valuable for studying the characteristics of PD activities. This paper proposes a method for estimating the energy of PD pulses in the presence of white noise and narrowband noise. First, a maximum likelihood (ML) estimator of the pulse energy is derived from the probability distribution of the energy spectral coefficients. To implement the ML method, the sampled data are divided into signal frames and noise frames. The noise frames are then utilized for extracting noise parameters using the 3F-C method. Eventually, these noise parameters are applied to the signal frames to find the ML estimate of the pulse energy. To verify the effectiveness of the proposed method, both simulated data and measured data have been processed using the proposed method and the conventional wavelet packet (WP) denoising method. Compared with the WP denoising method, the proposed method has a higher accuracy and is less susceptible to the lengths of the sampling time windows. The advantage of the method is more significant in unfavorable conditions where the signal-to-noise ratio is low and the accurate lengths of the PD pulses are difficult to determine.
关键词： white noise,maximum likelihood (ML) estimation,3F-C method,Partial discharge (PD),narrowband noise,energy estimation
更新于2025-09-23 15:21:01
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[IEEE 2018 International Conference on Power System Technology (POWERCON) - Guangzhou, China (2018.11.6-2018.11.8)] 2018 International Conference on Power System Technology (POWERCON) - Partial Discharge Detection in Transformer Based on Optical Method
摘要： The paper presents a method for detecting partial discharge (PD) in transformer oil using fluorescence sensor and optical method. The main components and the experimental setup are described. The results show that the fluorescence sensor can effectively detect PD signals with high sensitivity and accuracy. The method has great potential for application in power equipment monitoring.
关键词： fluorescence sensor,power equipment,optical detection,transformer oil,partial discharge
更新于2025-09-19 17:15:36
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Disturbed PD Detection System Based on Improved φ-OTDR Assisted by wFBG Array
摘要： A disturbed acoustic sensing system (DAS) based on improved φ-OTDR is proposed and experimentally demonstrated. A weak fiber Bragg grating (wFBG) array is introduced into sensing fiber to increase the signal to noise ratio (SNR) of system. In order to detecting the acoustic signals generated by partial discharge (PD) of 10KV power cables, the sensing fiber was packaged with an aluminium tape to enhance the sensitivity. The experimental results demonstrate the system performs well in demodulating PD signals, and has advantages of relatively high sensitivity and broadband frequency response.
关键词： weak fiber Bragg grating,Partial Discharge,φ-OTDR,acoustic detection
更新于2025-09-16 10:30:52
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Investigations on Novel Carbon Quantum Dots Covered Nanofluid Insulation for Medium Voltage Applications
摘要： The extensive use of mineral oil for high voltage insulation applications has directed to widespread research works targeted at improving its dielectric and thermal characteristics. The present study investigates a novel nanofluid insulation prepared using carbon quantum dots (CQD) which is used for the surface treatment of SiO2 nanoparticles added to commercially available mineral oil. The proposed nanofluid referred as CQD–SiO2 nanofluid is tested for its insulation properties such as AC breakdown voltage (BDV), partial discharge (PD), lightning impulse (LI), dissipation factor (Tan-delta), volume resistivity, viscosity and thermal characteristics such as flash and fire point. The tests were conducted for three different nanofluid concentrations, that is, 0.01%wt, 0.05%wt and 0.1%wt. Weibull distribution analysis is carried out for breakdown data of BDV test and LI test. Results of CQD–SiO2 nanofluid are compared with mineral oil with and without SiO2 nanofillers. The results show that inclusion of CQD covered SiO2 nanoparticles have the capability to improve the AC breakdown strength by more than 100%, partial discharge inception voltage by 50%, lightning impulse withstand capabilities up to 20% and volume resistivity by 50%. It has also the tendency to slightly improve the flash point and fire point properties than the mineral oil. Significant reduction of PD magnitude and Tan-delta values are noticed with CQD–SiO2 nanofluid. Such results indicate that the CQD–SiO2 nanofluid can be a suitable candidate for MV insulation applications.
关键词： Carbon quantum dots,Liquid insulators,Nanofluid,Breakdown voltage,Partial discharge
更新于2025-09-12 10:27:22
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A High Sensitivity Optical Fiber Interferometer Sensor for Acoustic Emission Detection of Partial Discharge in Power Transformer
摘要： We propose a Michelson ultrasonic sensing system for detecting the acoustic emission generated by the partial discharge in power transformer. In order to guide the sensor head design in the sensing system for high sensitivity, a theoretical model is established to investigate the effects of the sensor head dimensions on the response sensitivity. After that, an optimized sensor head is designed. In the frequency range from 80 kHz to 200 kHz, whether the PZT sensor is installed in the oil or on the tank, the average response sensitivity of the proposed sensing system is higher than that of the conventional PZT system. When the distance between the sensor head and ultrasonic source is 300 mm in oil, the average detection limit of the Michelson ultrasonic sensing system is about 0.26 Pa, which is about 18.6% of that of the PZT system. Moreover, experiment results show that the detectable partial discharge initial voltage for the proposed optical system is 21.5% lower than that for the PZT system. The enhanced sensitivity makes the Michelson ultrasonic sensing system a potential method to detect the small defects in power transformer.
关键词： Michelson interferometer,fiber coil effects,partial discharge,power transformer,optical fiber sensor
更新于2025-09-12 10:27:22
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Influence of surface charge decay on cavity PD frequency at DC voltage
摘要： In this study, two types of samples, i.e. a disc-shaped cavity embedded within solid dielectrics and the other on an electrode surface, were used to investigate partial discharge (PD) behaviours at DC voltage. It has been found that the discharge frequency of the sample with one metallic surface was much larger under a positive voltage than under a negative one, whereas it was not sensitive to voltage polarities for the sample with two insulating surfaces. In order to explain experimental results, a simulation model based on continuity equations was established to obtain PD sequences at DC voltage, in which surface charge decay and discharge time lag were taken into account. Simulation results showed that positive surface charges dissipated faster than the negative, and the discharge time lag kept almost unchanged at the same voltage amplitude. The discharge time interval consisted of field recovery time and discharge time lag, and the former was determined by surface charge decay rate. In terms of these, the effect of surface charge decay on discharge frequency was discussed. The research is helpful to clarify PD mechanism at DC voltage.
关键词： simulation model,partial discharge,discharge frequency,DC voltage,surface charge decay
更新于2025-09-11 14:15:04
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A High Sensitivity Optical Fiber Sensor for GIS Partial Discharge Detection
摘要： We propose a high sensitivity optical fiber sensor for detecting the acoustic emission generated by the partial discharge in gas-insulated-switchgear (GIS). A model is established to investigate the effects of the cylinder coil on the sensitivity, the bandwidth and the detection limit. After that, the proposed sensor was modified based on the effects. The average sensitivity of the optimized acoustic emission (AE) optical fiber sensor is 32 dB higher than that of the conventional lead zirconate titanate (PZT) in the frequency range from 20 kHz to 100 kHz. Moreover, experiment results show that the detectable partial discharge initial voltage for the proposed optical system is 17.1 % lower than that for the PZT system, and the amplitude of the signal detected by the proposed optical system is 525 % higher than that detected by the PZT system.
关键词： Michelson interferometer,GIS,partial discharge,cylinder coil effects,optical fiber sensor
更新于2025-09-11 14:15:04
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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 Method for Measurement of Step Voltage Rise Time of Partial Discharge Calibrators
摘要： The measurement methods of the step voltage rise-time of Partial Discharge calibrators are discussed. A method using a capacitor is recommended in the latest edition of IEC standard(IEC 60270-2015). However, the influences by the capacitance of cables and the capacitive component of the input impedance of the oscilloscope should not be neglected in the former method, especially for the measurement of the low-quantity discharge. A method for the measurement of the rise time of the step voltage by connecting a resistor to PD calibrators is presented. This method is more suitable for the measurement of charge transfers less than hundreds of picocoulombs.
关键词： apparent discharge,partial discharge,Measurement techniques,partial discharge calibrator,rise time
更新于2025-09-10 09:29:36
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[IEEE 2018 Condition Monitoring and Diagnosis (CMD) - Perth, WA (2018.9.23-2018.9.26)] 2018 Condition Monitoring and Diagnosis (CMD) - Pattern Recognition of Partial Discharge Image Based on One-dimensional Convolutional Neural Network
摘要： Big data platforms and centers are ubiquitous today where a large amount of unstructured data on site such as is accumulated. For structured data, partial discharge pattern recognition method has been extensively studied, whereas traditional methods can not be directly applied to unstructured data. To this end, a time-domain waveform pattern recognition method based on one- dimensional convolutional neural network (CNN) is proposed. Image processing techniques are applied to obtain one- dimensional characteristics of the waveform. Based on deep learning, the network is constructed for pattern recognition straight forwardly. Through on site detection and simulation experiments, image data sets of five partial discharge defects are established and comparative experiments are conducted. Experimental results show that the proposed method can successfully perform pattern recognition with applications in work of data mining and data utilization. Under the same complexity, it is also with higher accuracy comparing to two- dimensional CNN. Furthermore, the method autonomously extrapolates features without manual extraction, which achieves low experimental complexity and robustness simultaneously.
关键词： pattern recognition,image,partial discharge,convolutional neural network(CNN)
更新于2025-09-09 09:28:46