Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279645
Yifan Wang, Jinlong Gong, Zun Wang, Tao Ma, Liang Zhu, Shaohe Wang
This paper considers the calibration of Low-Power-Factor wattmeters in high voltage transformer no-load and load loss tests. The value of lowest power factor calibrated is evaluated in consideration of on-site test data and ability of uncertainty evaluation. The harmonic components of both testing current and voltage are measured in the field loss measurement. By analyzing the harmonic components, a nonsinusoidal current with a percentage of 3rd, 5th, 7th harmonic wave is applied for the laboratory calibration of Low-Power-Factor wattmeter in simulation of its on-site tests. There is a voltage unbalance in the field loss measurement. Unbalanced voltage is applied for Low-Power-Factor Wattmeters in comparison with balanced situations. For higher accuracy and resolution, the calibration systems of Low-Power-Factor wattmeters are improved with a nonsinusoidal current and unbalanced voltage standard.
{"title":"Calibration of Low-Power-Factor Wattmeters with a Nonsinusoidal Current and Unbalanced Voltage","authors":"Yifan Wang, Jinlong Gong, Zun Wang, Tao Ma, Liang Zhu, Shaohe Wang","doi":"10.1109/ICHVE49031.2020.9279645","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279645","url":null,"abstract":"This paper considers the calibration of Low-Power-Factor wattmeters in high voltage transformer no-load and load loss tests. The value of lowest power factor calibrated is evaluated in consideration of on-site test data and ability of uncertainty evaluation. The harmonic components of both testing current and voltage are measured in the field loss measurement. By analyzing the harmonic components, a nonsinusoidal current with a percentage of 3rd, 5th, 7th harmonic wave is applied for the laboratory calibration of Low-Power-Factor wattmeter in simulation of its on-site tests. There is a voltage unbalance in the field loss measurement. Unbalanced voltage is applied for Low-Power-Factor Wattmeters in comparison with balanced situations. For higher accuracy and resolution, the calibration systems of Low-Power-Factor wattmeters are improved with a nonsinusoidal current and unbalanced voltage standard.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"295 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73319646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Epoxy resin based composite insulation materials are widely used in power equipment, and they have also received extensive research. But the effects of the fillers on physical properties of epoxy resin has not yet formed a consistent law, and the mechanism has not been finalized. So, it is necessary to continue to study the characteristics of epoxy resin composites. In this paper, the epoxy/SiO2 composites were studied. By comparing the effects of different nano-SiO2 contents and the effects of the same content of micro-SiO2 and nano-SiO2, the results showed that the glass transition temperature, electrical conductivity and thermal stimulation current all exhibited novel trends. After the introduction of nano-silica, the glass transition temperature decreased, which indicated that the molecular chain was easier to move, and consequently the charge carriers were easier to migrate, leading a higher electrical conductivity. On the contrary, the effects of micro-SiO2 were not obvious.
{"title":"Glass transition temperatures and Charge Transport Characteristics of Epoxy/SiO2 Composites","authors":"Xiangnan Hu, Z. Xing, Shihang Wang, Jiucheng Wang, Jiao Xiang, Chuang Zhang, Jianying Li, Jian Gao","doi":"10.1109/ICHVE49031.2020.9280052","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9280052","url":null,"abstract":"Epoxy resin based composite insulation materials are widely used in power equipment, and they have also received extensive research. But the effects of the fillers on physical properties of epoxy resin has not yet formed a consistent law, and the mechanism has not been finalized. So, it is necessary to continue to study the characteristics of epoxy resin composites. In this paper, the epoxy/SiO2 composites were studied. By comparing the effects of different nano-SiO2 contents and the effects of the same content of micro-SiO2 and nano-SiO2, the results showed that the glass transition temperature, electrical conductivity and thermal stimulation current all exhibited novel trends. After the introduction of nano-silica, the glass transition temperature decreased, which indicated that the molecular chain was easier to move, and consequently the charge carriers were easier to migrate, leading a higher electrical conductivity. On the contrary, the effects of micro-SiO2 were not obvious.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"200 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80110464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279457
Xuanhong Liang, Youyuan Wang, Yubo Zhang, Dong Wang, Deying Ma
At present, the reading recognition of pointer type oil level meter mainly depends on manual observation, which is not accurate due to different scenes and perspectives. And traditional methods based on Hough transform are designed according to expert experience, which is inconvenient to be used by the staffs with little relevant work experience. To improve the automation degree of reading recognition, a model based on improved Resnet and improved Bayesian optimization is proposed in this paper. Firstly, convolution kernel decomposition, more shortcut connection and changeable network structure are adopted to improve Resnet18. Secondly, 3 constrains are added to improve Bayesian optimization to speed up the converge process and reduce network size. Finally, use the improve Bayesian optimization to search the suitable hyperparameter of the network, including initial learning rate, momentum of SGD, L2 regularization factor, filters number of first convolution layer, and the number of residual blocks. Example shows that the improved Bayesian optimization can help to converge faster with a small size of network, and improved Resnet performs the best compared with other classical deep learning network.
{"title":"A Reading Recognition Model of Pointer Type Oil-level Meter Based on Improved Resnet","authors":"Xuanhong Liang, Youyuan Wang, Yubo Zhang, Dong Wang, Deying Ma","doi":"10.1109/ICHVE49031.2020.9279457","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279457","url":null,"abstract":"At present, the reading recognition of pointer type oil level meter mainly depends on manual observation, which is not accurate due to different scenes and perspectives. And traditional methods based on Hough transform are designed according to expert experience, which is inconvenient to be used by the staffs with little relevant work experience. To improve the automation degree of reading recognition, a model based on improved Resnet and improved Bayesian optimization is proposed in this paper. Firstly, convolution kernel decomposition, more shortcut connection and changeable network structure are adopted to improve Resnet18. Secondly, 3 constrains are added to improve Bayesian optimization to speed up the converge process and reduce network size. Finally, use the improve Bayesian optimization to search the suitable hyperparameter of the network, including initial learning rate, momentum of SGD, L2 regularization factor, filters number of first convolution layer, and the number of residual blocks. Example shows that the improved Bayesian optimization can help to converge faster with a small size of network, and improved Resnet performs the best compared with other classical deep learning network.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"506 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77066589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Infrared thermography has been widely used in timely detection of overheating defects in cable accessories. However, the traditional manual diagnosis method is time-consuming and laborious, and it relies too much on expert experience. An autonomous diagnosis method, which is based on the Faster RCNN network and the Mean-Shift algorithm, is proposed in this paper. Firstly, the Faster RCNN network is trained to implement the autonomous identification and positioning of the objects to be diagnosed in images (cable terminations and grounding boxes are included in this paper). Then, the Mean-Shift algorithm is used for image segmentation to rapidly and accurately extract the area of overheating. This is achieved via comparing key regions of the three phase accessories. Next the temperature related characteristic parameters of the overheating region are calculated, and the diagnosis results are obtained in accordance with the relevant cable condition assessment criteria. The proposed method has been applied to test against actual infrared images, and results show that the cable accessories and their overheating regions can be located at different shooting angles and under various background conditions. The research helps reduce the dependence on human efforts and expertise and contributes to improving the practice of condition monitoring.
{"title":"Autonomous Diagnosis of Overheating Defects in Cable Accessories Based on Faster RCNN and Mean-Shift Algorithm","authors":"Xiaobing Xu, Chengke Zhou, Wenjun Zhou, Yanqun Liao, Yilong Wei, Jing Yuan","doi":"10.1109/ICHVE49031.2020.9280056","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9280056","url":null,"abstract":"Infrared thermography has been widely used in timely detection of overheating defects in cable accessories. However, the traditional manual diagnosis method is time-consuming and laborious, and it relies too much on expert experience. An autonomous diagnosis method, which is based on the Faster RCNN network and the Mean-Shift algorithm, is proposed in this paper. Firstly, the Faster RCNN network is trained to implement the autonomous identification and positioning of the objects to be diagnosed in images (cable terminations and grounding boxes are included in this paper). Then, the Mean-Shift algorithm is used for image segmentation to rapidly and accurately extract the area of overheating. This is achieved via comparing key regions of the three phase accessories. Next the temperature related characteristic parameters of the overheating region are calculated, and the diagnosis results are obtained in accordance with the relevant cable condition assessment criteria. The proposed method has been applied to test against actual infrared images, and results show that the cable accessories and their overheating regions can be located at different shooting angles and under various background conditions. The research helps reduce the dependence on human efforts and expertise and contributes to improving the practice of condition monitoring.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"22 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77167897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279522
Chaoyong Li, Huimin Wang, Ming Wang, Shaolong Ma, Tianran Gao, Feng Wang, She Chen
Cross-linked polyethylene (XLPE) power cable is widely used in AC/DC transmission and distribution system. The insulation defects of the cable may lead to safety problems and economic losses. Electrical capacitance tomography (ECT) technology can be used to show the distribution of dielectric constants of insulation layer, and thus detecting insulation defects of XLPE cable and its accessories. Because of the ‘soft field’ effect in the sensitivity field of ECT system, it is necessary to optimize the structure and parameters of capacitive sensor for more accurate images. In this paper, the model of 8-electrode ECT sensor is constructed, and its geometrical parameters, including electrode thickness, electrode angle and the ratio between the radius of the shielding and the cable, are optimized by orthogonal experiment design. The signal strength and the uniformity of sensitivity field distribution are taken as the evaluation indicators. The simulation results show that the setting of the shield has a great influence on the indicators. When the shielding layer is too close to the cable, the uniformity of the sensitivity field is influenced. However, the influence of electrode thickness and angle on signal strength and sensitivity field uniformity is relatively small.
{"title":"Optimization of Geometrical Parameters of ECT Sensor for Power Cable Insulation Detection","authors":"Chaoyong Li, Huimin Wang, Ming Wang, Shaolong Ma, Tianran Gao, Feng Wang, She Chen","doi":"10.1109/ICHVE49031.2020.9279522","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279522","url":null,"abstract":"Cross-linked polyethylene (XLPE) power cable is widely used in AC/DC transmission and distribution system. The insulation defects of the cable may lead to safety problems and economic losses. Electrical capacitance tomography (ECT) technology can be used to show the distribution of dielectric constants of insulation layer, and thus detecting insulation defects of XLPE cable and its accessories. Because of the ‘soft field’ effect in the sensitivity field of ECT system, it is necessary to optimize the structure and parameters of capacitive sensor for more accurate images. In this paper, the model of 8-electrode ECT sensor is constructed, and its geometrical parameters, including electrode thickness, electrode angle and the ratio between the radius of the shielding and the cable, are optimized by orthogonal experiment design. The signal strength and the uniformity of sensitivity field distribution are taken as the evaluation indicators. The simulation results show that the setting of the shield has a great influence on the indicators. When the shielding layer is too close to the cable, the uniformity of the sensitivity field is influenced. However, the influence of electrode thickness and angle on signal strength and sensitivity field uniformity is relatively small.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"5 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82269018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279693
Yunhui Zhang, Jiangrong Chen, Xing Li, Weidong Liu
Recent research results and on-site operation experience have shown that there may be small and sporadic partial discharge (PD) before some insulation flashover, but the existing online monitoring methods cannot effectively monitor them, which may cause non-early-warning failures. Pulse excitation measurement method can be used to effectively improve the data storage efficiency, and can realize the high-precision and long-term measurement of sporadic pulses. However, further analysis of discharge characteristics and fault location need to screen and identify discharge pulses from a large number of signals, including interference signals. In this process, small and sporadic pulses are very likely to be ignored, which will affect subsequent analysis and judgment. Therefore, in this paper, a feature extraction method based on the signal spectrum was proposed, and the DBSCAN density clustering algorithm was used to process the discharge signals, which can classify the discharge signal automatically and effectively so that a large number of pulse signals can be screened and identified efficiently and quickly, to solve the identification problem of small and sporadic pulses, and to avoid the non-early-warning faults of the equipment to a large extent. At the same time, it also lays a good foundation for the subsequent pattern recognition and fault location, which makes greatly improve the efficiency of the overall processing of the PD signal.
{"title":"Segmented Spectrum Energy Characteristics-based Density Clustering of Partial Discharge Signals","authors":"Yunhui Zhang, Jiangrong Chen, Xing Li, Weidong Liu","doi":"10.1109/ICHVE49031.2020.9279693","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279693","url":null,"abstract":"Recent research results and on-site operation experience have shown that there may be small and sporadic partial discharge (PD) before some insulation flashover, but the existing online monitoring methods cannot effectively monitor them, which may cause non-early-warning failures. Pulse excitation measurement method can be used to effectively improve the data storage efficiency, and can realize the high-precision and long-term measurement of sporadic pulses. However, further analysis of discharge characteristics and fault location need to screen and identify discharge pulses from a large number of signals, including interference signals. In this process, small and sporadic pulses are very likely to be ignored, which will affect subsequent analysis and judgment. Therefore, in this paper, a feature extraction method based on the signal spectrum was proposed, and the DBSCAN density clustering algorithm was used to process the discharge signals, which can classify the discharge signal automatically and effectively so that a large number of pulse signals can be screened and identified efficiently and quickly, to solve the identification problem of small and sporadic pulses, and to avoid the non-early-warning faults of the equipment to a large extent. At the same time, it also lays a good foundation for the subsequent pattern recognition and fault location, which makes greatly improve the efficiency of the overall processing of the PD signal.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"50 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78791281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phenomenon of partial discharge of soil that occurs when a lightning current enters the ground through a ground electrode poses a threat to the safety of personnel and equipment. The strength of partial discharge and the formation of soil discharge channels are closely related to the magnitude of the critical breakdown field strength. Therefore, how to accurately obtain the variation law of the critical breakdown field strength of typical soil is the key to realize the safe operation of the grounding device and the cable in the ground and ensure the safety of personnel and equipment. In this paper, a simulation experiment of soil impact characteristics is used to study the variation law of typical soil critical breakdown field strength with soil properties. X-ray transmission imaging technology is used to obtain the morphology of the discharge channel, and its non-intrusive observation method will not disturb the discharge channel itself, making the measurement more accurate. This paper first selects a variety of typical soils to study the influence of soil moisture, salt content, compactness and other factors on the discharge channel morphology, and then studies the calculation method of the critical breakdown field strength of the soil under different discharge channel morphologies. And further explore the reasons for the influence of typical soil media factors on the critical breakdown field strength. The experimental results show that under the same conditions, the relationship between the critical breakdown field strength values of different soils is: Ec of sandy soil
{"title":"Study on the influence law of typical soil parameters based on discharge morphology on critical breakdown field strength","authors":"Shizun Pu, Jialun Li, Hongmei Li, Pinglin Liu, Qingjun Peng, T. Yuan","doi":"10.1109/ICHVE49031.2020.9279579","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279579","url":null,"abstract":"The phenomenon of partial discharge of soil that occurs when a lightning current enters the ground through a ground electrode poses a threat to the safety of personnel and equipment. The strength of partial discharge and the formation of soil discharge channels are closely related to the magnitude of the critical breakdown field strength. Therefore, how to accurately obtain the variation law of the critical breakdown field strength of typical soil is the key to realize the safe operation of the grounding device and the cable in the ground and ensure the safety of personnel and equipment. In this paper, a simulation experiment of soil impact characteristics is used to study the variation law of typical soil critical breakdown field strength with soil properties. X-ray transmission imaging technology is used to obtain the morphology of the discharge channel, and its non-intrusive observation method will not disturb the discharge channel itself, making the measurement more accurate. This paper first selects a variety of typical soils to study the influence of soil moisture, salt content, compactness and other factors on the discharge channel morphology, and then studies the calculation method of the critical breakdown field strength of the soil under different discharge channel morphologies. And further explore the reasons for the influence of typical soil media factors on the critical breakdown field strength. The experimental results show that under the same conditions, the relationship between the critical breakdown field strength values of different soils is: Ec of sandy soil <Ec of loam soil <Ec of pastoral soil; It is precisely because of the different reasons that different factors of the soil medium affect the critical breakdown field strength, the content of water and air inside the soil and the conductivity of the soil are different, so that the variation law of the critical breakdown field strength is different.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"67 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76035253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9280010
Jian Zou, Xia Zheng, N. Zeng, Xingdong Jiang, Tianjue Zhang
In order to carry out X-pinch related experimental research, a new one-day experimental circuit has been established on the side of Light-II Pulse Power Generator (250 kA/50ns) at China Institute of Atomic Energy. On the basis of retaining the original pumping laser capacity of the device, X-pinch related experimental research can be carried out at the same time. Two groups of X-pinch were driven by Light- II, one group was placed in the anode and the other group was placed in the reflux disk. The time difference was used to conduct the backlight imaging experiment of plasma distribution in the process of X-pinch self-explosion, and the sequence images of different times of X-pinch development were obtained. In the picture, the halo layer, pinch, implosion and final collapse dissipation of the plasma at the X-pinch point can be observed. The experimental results are helpful to further understand the physical mechanism of X-pinch plasma development. At the same time, X-pinch biological phase contrast imaging experiment was carried out, and high-resolution biological imaging pictures were obtained.
{"title":"Experimental study of pulsed X-ray imaging based on wire load","authors":"Jian Zou, Xia Zheng, N. Zeng, Xingdong Jiang, Tianjue Zhang","doi":"10.1109/ICHVE49031.2020.9280010","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9280010","url":null,"abstract":"In order to carry out X-pinch related experimental research, a new one-day experimental circuit has been established on the side of Light-II Pulse Power Generator (250 kA/50ns) at China Institute of Atomic Energy. On the basis of retaining the original pumping laser capacity of the device, X-pinch related experimental research can be carried out at the same time. Two groups of X-pinch were driven by Light- II, one group was placed in the anode and the other group was placed in the reflux disk. The time difference was used to conduct the backlight imaging experiment of plasma distribution in the process of X-pinch self-explosion, and the sequence images of different times of X-pinch development were obtained. In the picture, the halo layer, pinch, implosion and final collapse dissipation of the plasma at the X-pinch point can be observed. The experimental results are helpful to further understand the physical mechanism of X-pinch plasma development. At the same time, X-pinch biological phase contrast imaging experiment was carried out, and high-resolution biological imaging pictures were obtained.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"15 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87769852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279926
Yongjie Nie, Xianping Zhao, Na Zhao, Siyang Liu, Shihu Yu, Shengtao Li
In this paper, Low density polyethylene (LDPE) films were surface treated in ozone atmosphere for different times (Oh, 1h, 2h, 4h, and 6h) to investigate the effect of surface oxidation on DC surface flashover characteristics in vacuum. Infrared (IR) was used to characterize surface chemical structure of specimens before and after ozone treatment. IR results show that oxygen atoms (O) are introduced into LDPE surface layer and carbonyl groups (C=O) are formed after surface treatment. Surface conductivity of specimens was tested and the results show surface conductivity increases with the extending of surface ozone treatment time. For untreated LDPE, surface conductivity is 4.39× 10−18S, and it increases to 1.01×10−15Swhen LDPE specimen is surface treated for 6h with ozone. Surface potential decay (SPD) was used to characterize surface trap distribution of specimens, and the results show surface potential decays faster and faster with the increasing treatment time, which is resulted from the shallower trap centers introduced into LDPE surface layers after ozone treatment. Surface flashover performance measurement results show that surface flashover voltage of LDPE specimens is improved by surface ozone treatment, and the optimum value of flashover voltage for treated 4 hours specimen is improved by 25.59% compared with untreated LDPE. Finally, the mechanism of surface flashover is discussed and it concludes that the change of surface chemical structure resulting from surface ozone treatment leads to the variation of surface trap distribution and surface conductivity which influences the surface charge accumulation properties, and then improves surface flashover performance of LDPE in vacuum.
{"title":"A New Surface Treatment Method for Improving Surface Flashover Performance of Polymers in Vacuum","authors":"Yongjie Nie, Xianping Zhao, Na Zhao, Siyang Liu, Shihu Yu, Shengtao Li","doi":"10.1109/ICHVE49031.2020.9279926","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279926","url":null,"abstract":"In this paper, Low density polyethylene (LDPE) films were surface treated in ozone atmosphere for different times (Oh, 1h, 2h, 4h, and 6h) to investigate the effect of surface oxidation on DC surface flashover characteristics in vacuum. Infrared (IR) was used to characterize surface chemical structure of specimens before and after ozone treatment. IR results show that oxygen atoms (O) are introduced into LDPE surface layer and carbonyl groups (C=O) are formed after surface treatment. Surface conductivity of specimens was tested and the results show surface conductivity increases with the extending of surface ozone treatment time. For untreated LDPE, surface conductivity is 4.39× 10−18S, and it increases to 1.01×10−15Swhen LDPE specimen is surface treated for 6h with ozone. Surface potential decay (SPD) was used to characterize surface trap distribution of specimens, and the results show surface potential decays faster and faster with the increasing treatment time, which is resulted from the shallower trap centers introduced into LDPE surface layers after ozone treatment. Surface flashover performance measurement results show that surface flashover voltage of LDPE specimens is improved by surface ozone treatment, and the optimum value of flashover voltage for treated 4 hours specimen is improved by 25.59% compared with untreated LDPE. Finally, the mechanism of surface flashover is discussed and it concludes that the change of surface chemical structure resulting from surface ozone treatment leads to the variation of surface trap distribution and surface conductivity which influences the surface charge accumulation properties, and then improves surface flashover performance of LDPE in vacuum.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"8 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87811744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9280066
Shengwu Tan, Pengchao Wang, Junping Zhao, Hao Yang, R. Wen
Flashover of contaminated insulators is one of the major problems for the power distribution. Laboratory experiments have shown that the arc characteristics have great influences on the study of flashover performance of contaminated insulators. In order to investigate the characteristics of AC arc discharge on the polluted insulation surface, an experimental system was designed. The tests were carried out in the climate chamber. The optical emission spectroscopy was obtained by employing the fiber-optic spectrometer with shortest exposure time of 1 ms. The light emitted from the arc was coupled to the spectrometer by means of a focusing lens and a 3 m optical fiber. Typical optical emission spectrogram of different stages were obtained, and kinetics equation of different particles in the arc column was analyzed. And the spectrogram used for the prediction of critical flashover was proposed. It was shown that emission spectrum mainly includes sodium atom line and potassium atom line. With the increase of leakage current, the thickness of the continuous spectrum, spectral line intensity and the spectral composition increased. This work can enrich the investigation of partial arc parameters and may provide useful reference for the calculation of contamination flashover.
{"title":"Study on the Typical Optical Emission Spectrograms of AC Arc Discharge over the Polluted Insulation Surface","authors":"Shengwu Tan, Pengchao Wang, Junping Zhao, Hao Yang, R. Wen","doi":"10.1109/ICHVE49031.2020.9280066","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9280066","url":null,"abstract":"Flashover of contaminated insulators is one of the major problems for the power distribution. Laboratory experiments have shown that the arc characteristics have great influences on the study of flashover performance of contaminated insulators. In order to investigate the characteristics of AC arc discharge on the polluted insulation surface, an experimental system was designed. The tests were carried out in the climate chamber. The optical emission spectroscopy was obtained by employing the fiber-optic spectrometer with shortest exposure time of 1 ms. The light emitted from the arc was coupled to the spectrometer by means of a focusing lens and a 3 m optical fiber. Typical optical emission spectrogram of different stages were obtained, and kinetics equation of different particles in the arc column was analyzed. And the spectrogram used for the prediction of critical flashover was proposed. It was shown that emission spectrum mainly includes sodium atom line and potassium atom line. With the increase of leakage current, the thickness of the continuous spectrum, spectral line intensity and the spectral composition increased. This work can enrich the investigation of partial arc parameters and may provide useful reference for the calculation of contamination flashover.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"24 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87869675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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