Gu Yu, Bingbing Dong, Zelin Zhang, N. Xiang, Du Bin, Zhang Zhu
{"title":"Simulation calculation and analysis on three-dimensional electrothermal coupling of a new type of current transformer for distribution network","authors":"Gu Yu, Bingbing Dong, Zelin Zhang, N. Xiang, Du Bin, Zhang Zhu","doi":"10.1109/ICHVE49031.2020.9279983","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279983","url":null,"abstract":"In recent years, the new type current transformer with bushing structure has been widely used in the distribution network system due to its advantages of miniaturization, high mechanical strength, maintenance-free, safety and environmental protection. The distribution of electric field and temperature field inside the transformer are important characteristic parameters to characterize its electrical insulation and aging performance. Then, the electric field distribution of inner conductor, secondary winding and insulating medium of CT is mainly determined by the applied voltage and relative dielectric constant, while the distribution of the temperature field mainly comes from ohmic heat of primary current and joule heat of insulating medium. Therefore, the study on the electro-thermal coupling field of CT is more complicated and necessary. In this paper, a 3D simulation model of a new type of current transformer for distribution network based on electric-thermal coupling is established by using finite element software. Considering that the actual thermal conduction process of CT is mainly by conduction, convection and radiation, three different kinds of boundary conditions such as solid heat transfer boundary condition, heat convection boundary condition and surface radiation boundary condition are applied to the CT. Through the model created above, the temperature rise process and the distribution characteristics of temperature of the CT under different current conditions are studied. Meanwhile, the maximum field strength and the hottest temperature of the CT are calculated. According to this, the position of weak insulation of the transformer is determined. The research results can provide a reference for the factory production of new type current transformer.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"43 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":"73638419","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}
{"title":"Effects of impulse polarity on grounding systems","authors":"A. W. Ali, N. Ahmad, N. M. Nor","doi":"10.1109/ICHVE49031.2020.9279482","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279482","url":null,"abstract":"In earlier paper, experimental results of 1-rod, 2-rod and 3-rod electrodes under high magnitude impulse currents of positive polarity were presented. In the paper, it was noticed that lower reduction of impulse resistance from its steady-state ground resistance value, RDC in large size of grounding electrodes (3-rod electrodes). The paper also showed a significant increase of current rise time in 3-rod electrodes, for current magnitudes of below 1.5 kA, indicating an inductive effect in large grounding electrodes. The results on the performance of grounding systems for increasing number of rods were only presented for positive impulse polarity.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"51 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":"73665447","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}
{"title":"Research on Miniaturized Ultra-High Voltage and High Power Supply","authors":"M. Fu, Zicai Wang, Donglai Zhang, Hua Zhang","doi":"10.1109/ICHVE49031.2020.9279662","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279662","url":null,"abstract":"A miniaturized ultra-high voltage and high power supply (uHV power supply) is proposed in this paper by choosing the full-wave Cockcroft-Walton voltage multiplier. The voltage multiplier on the secondary side of main power transformer and the isolated resonant current-fed inverter on the primary side are described in detail, including the condition of high voltage rectifier diode working in soft recovery, the design of isolated high power resonant current-fed inverter and its corresponding control mode under the former condition. Additionally, the simulation results of the proposed uHV power supply show that the voltage multiplier diode always works in the soft recovery switching state, and the output voltage ripple peak-to-peak value is smaller than 20V, that is, there is significant improvement in the operating frequency and decrease in the output voltage ripple, in agreement with the expected miniaturization purpose of uHV power supply.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"43 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":"74660929","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}
Ruifang Li, Chenxia Gao, Xiaobin Cao, Hao Du, Zhihao Lin, Tao Li
{"title":"Research on three-dimensional development simulation modeling method of lightning channel based on simulated charge method","authors":"Ruifang Li, Chenxia Gao, Xiaobin Cao, Hao Du, Zhihao Lin, Tao Li","doi":"10.1109/ICHVE49031.2020.9279552","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279552","url":null,"abstract":"The development model of the lightning channel is the basis for studying the distribution of ground lightning density. The existing lightning channel simulation model is based on two-dimensional model, and the electric field strength distribution in space is calculated by the simulation charge method, so as to simulate the development process of lightning channel. However, the actual lightning channel condition is a three-dimensional structure, and the two-dimensional model cannot truly reflect the impact of the three-dimensional environment on the lightning channel. For this reason, it is necessary to study the three-dimensional development simulation modeling method of the lightning channel. This paper proposes the development model of lightning channel with 17 degrees of freedom in the first place. Based on the development direction and inclination of these 17 free leaders, the calculation formulas of the electric field intensity of the three-dimensional space pilot head are deduced. In this paper, the simulated charge method is used for calculation, and it is found that the transition condition will reach at the initial stage of lightning process when the lightning channel is too high. Because the development direction of lightning has a strong probability characteristic, which is very obvious in three-dimensional space. As a result, lightning could breakdown at higher altitudes. In this paper, by studying the viaducts of different heights and the initial lightning displacement in different directions, it is proposed that the increase in the viaduct height will increase the lightning stroke rate of the catenary system; the initial lightning displacements in different directions will make the left and right space field imbalance and the effect is enhanced to increase the lightning stroke rate on the offset side. Finally, by changing the initial position of the lightning channel, this paper limits the influence of the height of the lightning channel on the electric field to a certain range, and proposes a three-dimensional development simulation modeling method of the lightning channel.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"4 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":"75308320","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}
P. Wouters, Anni Tong, A. van Deursen, P. van der Wielen, Yan Li
{"title":"Temperature Dependency of Transient Signal Propagation in Underground Power Cables","authors":"P. Wouters, Anni Tong, A. van Deursen, P. van der Wielen, Yan Li","doi":"10.1109/ICHVE49031.2020.9279824","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279824","url":null,"abstract":"The temperature dependency of transient signal propagation in multi-conductor power cables is investigated. The sensitivity of the propagation velocity variation upon temperature is studied for a mass-impregnated medium-voltage cable in service. Data on almost one year monitoring of a medium-voltage cable with dynamic loading indicate that temperature differences down to 1 °C can be detected from the signal propagation time. This sensitivity opens the possibility to make use of signal propagation information for dynamic rating of power cables. To this end, the signal propagation modes are investigated for a three-phase medium-voltage cable based on a simulated temperature distribution for a loaded cable and the measured temperature dependency of the permittivity.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"1 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":"75693974","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}
Xuri Xu, Yu Gao, Jing Li, Zheng Song, Jinjing Peng, B. Du
{"title":"Charge Transport and DC Breakdown in Polymer Based Micro/Nano-Composite with Different Filler Orientations","authors":"Xuri Xu, Yu Gao, Jing Li, Zheng Song, Jinjing Peng, B. Du","doi":"10.1109/ICHVE49031.2020.9279644","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279644","url":null,"abstract":"Hexagonal boron nitride (h-BN) has been extensively considered as filler in order to improve thermal conductivity of the polymeric materials. As a 2D material, the orientation of h-BN will affect the insulation property of the polymer. Therefore, it is important to understand the influence of filler orientations on the insulation performance of the polymer. In this work, the orientations of the h-BN fillers were assumed to be parallel, perpendicular to the normal vector of sample surface or randomly distributed in the matrix, and the charge transport behavior and DC breakdown strength in different samples were discussed. The bipolar charge transport (BCT) model has been adopted to estimate the charge transport and the breakdown behavior in the micro/nano-composite with the purpose of better understanding the orientation effect. The obtained results indicated that the density of trapped charge was the largest in the sample with filler distributing perpendicularly compared with others and the breakdown of the polymer with vertical filler orientation could occur first. It is suggested that the material with the parallel orientation of the filler is expected to improve the insulation performance of the polymer.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"19 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":"73872554","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}
{"title":"Non-contact Method for Dielectric Response Measurements","authors":"J. Hao, X. Xu, J. Cheng, N. Taylor","doi":"10.1109/ICHVE49031.2020.9279577","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279577","url":null,"abstract":"The dielectric response measurement is an important technique to assess the properties of insulation materials. However, the widely used approach with contact between samples and electrodes can in some cases limit the accuracy of the measurement. In this paper, an easily fabricated design is introduced and used to perform non-contact measurements. Air-reference measurements, comparing the sample to an air-gap for improved calibration, are used for all measurements. Results obtained by contact and non-contact methods, and with the feedback of electrometer locked and unlocked are compared. The effect of the pressure applied by the electrode is also investigated for both non-contact and contact measurements. Results show that the non-contact method can be an alternative to reduce contact problems between the sample and electrodes. For air-reference measurements, the impedance measurement instrument should be forced to use the same reference component for the air and sample measurements. Results obtained by the non-contact measurements are less sensitive to the pressure compared to that by contact measurements.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"12 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":"74281659","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}
{"title":"Two test methods for obtaining activation energy of epoxy resin and their effectiveness analysis","authors":"Q. Tang, Xue Li, Wei Yan, Q. Liu, Honglei Liu, P. Ren","doi":"10.1109/ICHVE49031.2020.9279446","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279446","url":null,"abstract":"Activation energy, as an intrinsic property to characterize the insulation state of materials, has important applications in the aging state and life assessment of insulating materials. How to calculate the activation energy of epoxy resin accurately and how to grasp the applicability of different calculation methods are the hot issues in current research. At present, the main methods of calculating activation energy include thermogravimetric method and dielectric spectrum method. there are some differences in the physicochemical connotation of activation energy obtained by these two methods. This paper introduces the method of obtaining activation energy and its applicability. With epoxy resin as an example, analysis of the two kinds of activation energy of the physical and chemical process, studies the thermogravimetric method of chemical activation energy and the dielectric spectrum method to calculate the relaxation activation energy, the results show that chemical activation energy on behalf of the energy required to overcome the barrier of the chemical reaction, relaxation activation energy represents the micro motion unit under the effect of electric field to move the energy to overcome. The activation energies measured by the two methods are obviously different, and their application ranges are also obviously different.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"138 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":"75068085","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}
Wei Wang, Zhaohui Wang, W. Bu, Xilin Yan, Zhiqiang Guo, Xin Wang
{"title":"Influence of capacitive parameters on the overvoltage characteristics of three-core submarine cable","authors":"Wei Wang, Zhaohui Wang, W. Bu, Xilin Yan, Zhiqiang Guo, Xin Wang","doi":"10.1109/ICHVE49031.2020.9279763","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279763","url":null,"abstract":"Over-voltage in submarine cable plays an important role in the cable failure and the collapse of the connected power system. Previous studies focused on the effects of circuit parameters of power transmission line on over-voltage characterisitics. However, in the case of long distance submarine cable, the effects of cable parameters, especially for capacitive parameters can not be ignored. In this paper, the influence of capacitive parameters on the over-voltage characteristics of a 35 kV three-core submarine cable is studied. A simulation model is constructed by PSCAD/EMTDC software to calculate the transient over-voltage and over-current characteristics under the fault conditions. Particularly, the relative permittivity of the insulation layer and the reactive compensation are carried out. The results show that when the line operates with no load, the terminal voltage rise and reactive power increase with the increase of the relative permittivity of the insulation material. The single-phase grounding fault gives rise to a 1.5 times overvoltage amplitude and an overcurrent of 860 A. In addition, 1100V over-voltage will be induced on the metal sheath of the submarine cable. With an increase of relative permittivity, the overvoltage value caused by the single-phase grounding increases.","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":"75138961","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}
Xu Yang, Yi Liu, Yi Jiang, Hao Wen, Jing Zhang, Jia Chen
{"title":"State Assessment of GIS Partial Discharge Based on Chemical Analysis Method","authors":"Xu Yang, Yi Liu, Yi Jiang, Hao Wen, Jing Zhang, Jia Chen","doi":"10.1109/ICHVE49031.2020.9280073","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9280073","url":null,"abstract":"In order to use SF<inf>6</inf> decomposition characteristics to assess the partial discharge (PD) degree of DC gas-insulated switchgear (GIS), the authors studied the PD characteristics of the whole process from the initial discharge to the near breakdown of the free conductive particle defect in DC GIS. <tex>$pmb{q}_{pmb{v}}, pmb{n}_{pmb{v}}$</tex>, and <tex>$Delta pmb{t}_{pmb{v}}$</tex> are selected as the feature quantities for characterizing the PD state, and the PD severity is divided into three levels. Then, a large number of SF<inf>6</inf> decomposition experiments were carried out under three PD level, and the decomposition characteristics of SF<inf>6</inf> were obtained. The experimental results show that SF<inf>6</inf> decomposition produces include five stable components of CF<inf>4</inf>, CO<inf>2</inf>, SO<inf>2</inf>F<inf>2</inf>, SOF<inf>2</inf> and SO<inf>2</inf>, among which SOF<inf>2</inf> is the most important decomposition product, and the concentration of the remaining four products is close to each other. Finally, it is proposed to use the concentration ratios <tex>$pmb{R}$</tex> (CF<inf>4</inf>/CO<inf>2</inf>) and <tex>$pmb{R}$</tex> [SO<inf>2</inf>F<inf>2</inf>/(SOF<inf>2</inf>+SO<inf>2</inf>)] as characteristic quantities to study the correlation between SF<inf>6</inf> decomposition components and PD degree. And based on the C4.5 algorithm, a decision tree for the PD degree assessment is constructed with an accuracy rate of 91.67%.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"90 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":"77952044","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}