{"title":"Electro-Thermal Stress of Dielectric Coated Electrodes in Gas-Insulated Systems under DC Voltage Stress","authors":"T. Götz, A. Markl, K. Backhaus, U. Riechert","doi":"10.1109/ICD46958.2020.9342012","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9342012","url":null,"abstract":"The use of high-voltage direct current (HVDC) links becomes economic for the transport of electrical energy over vast distances. Gas-insulated systems (GIS) provide advantages due to a compact design, high reliability and independence from environmental conditions. A combination of both technologies for converter stations on e.g. offshore platforms has various technological and economical advantages. In contrast to AC-GIS there is a lack of experience in the application of DC-GIS in transmission systems. In comparison to AC applications, changed electrical stresses under DC voltage require the development of new dimensioning guidelines. Charge carriers can accumulate on dielectric coated surfaces and can lead to surface discharges at the gas-solid interface. The experimental investigations show that the surface discharge behaviour is strongly temperature dependent, due to the temperature dependent electric conductivity of the used coating material. A safe and reliable operation of high-voltage devices can be ensured by partial discharge (PD) measurements. The most common used method for PD detection according to IEC 60270 is suitable for a reliable detection of surface discharges in gas-insulated DC systems.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"16 1","pages":"665-668"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82247469","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}
G. R. Rodríguez, L. Garelli, Mario Alberto Storti, Krzysztof Kubiczek, P. Lasek, M. Stępień, Michal Stebel, B. Melka, J. Bodys, M. Haida, M. Palacz, J. Smolka, F. Pessolani, Mauro Amadei
{"title":"Coupled CFD and electromagnetic analysis of an ONAN distribution transformer cooled with mineral oil and biodegradable esters","authors":"G. R. Rodríguez, L. Garelli, Mario Alberto Storti, Krzysztof Kubiczek, P. Lasek, M. Stępień, Michal Stebel, B. Melka, J. Bodys, M. Haida, M. Palacz, J. Smolka, F. Pessolani, Mauro Amadei","doi":"10.1109/ICD46958.2020.9341955","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341955","url":null,"abstract":"This work describes the electromagnetic and coupled thermo-fluid dynamic analysis of an oil-natural air-natural (ONAN) distribution transformer with the main objective of studying the changes in the heat dissipation performance when the fluid employed to cool the machine is a biodegradable ester instead of mineral oil. The distribution transformer under analysis has a rated power of 315 kVA with a voltage ratio of 13.2 kV / 0.4 kV. The heat losses in the magnetic core and the windings are computed with the ANSYS Maxwell software on suitable finite element meshes. These heat losses are then transferred as volume heat source terms to appropriate finite volume meshes which are used to compute the heat conduction in the core and windings, then the heat dissipates to the oil by convection, afterwards to the walls of the oil tank and to the radiators panels and finally to the surrounding air. In the thermo-fluid dynamic model, the natural convection of the fluid flow is taken into account using a temperature-dependent density. Moreover, the heat conduction through the metal sheet of the oil tank and the radiators panels are considered. The coupled thermo-hydraulic problem is solved with Code_Satume software. The experimental data of the total power losses provided by the unit manufacturer were employed to validate the electro- magnetic model. Because the thermo-fluid dynamic numerical model is computationally expensive, only one quarter of the transformer is modelled. In addition, equivalent anisotropic thermal conductivity in the core and windings are calculated to simplify the heat conduction model in the active parts. The differences in the temperature distribution and oil flow observed between the transformer working with a standard mineral oil and a biodegradable ester are discussed. This work is carried out as part of the EU Horizon 2020 BIOTRAFO project.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"135 1","pages":"766-769"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86297585","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}
Q. Han, I. Iddrissu, P. Ranjan, L. Chen, I. Cotton
{"title":"The Effect of Humidity on DC Breakdown Characteristic of C3F7CN and CO2 Gas Mixture","authors":"Q. Han, I. Iddrissu, P. Ranjan, L. Chen, I. Cotton","doi":"10.1109/ICD46958.2020.9342016","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9342016","url":null,"abstract":"By-products of SF6 react with water and lead to the formation of highly toxic decomposition products, which cause a reduction in breakdown performance. However, there is limited work carried out on the humidity effect on the DC breakdown characteristics of SF6 alternatives. This paper aims to characterize the effect of humidity of a pre-determined $C_{3}F_{7}$CN/CO2 gas mixture that matches the dielectric performance of SF6. Different humidity levels ranging from 109 to 8,306 ppmv were tested using negative DC for a 20‥ $C_{3}F_{7}$CN and 80‥ CO2 gas mixture at 2 bar (abs) and a hemisphere-plane configuration (hemisphere dia. of 8.8 mm) with gaps of 3 to 5 mm. Results indicate that breakdown voltage decreases with increasing humidity content within the $C_{3}F_{7}$CN gas mixture. X-ray photoelectron spectroscopy (XPS) analysis was conducted on the electrode surface after the experiment. The study showed that the deposited film on the electrode surface was mainly metal oxide and fluoride. As a result, the presence of humidity not only reduces the breakdown performance of the $C_{3}F_{7}$CN/CO2 gas mixture but also causes characteristic change to the surface of the electrode material.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"18 1","pages":"786-789"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87934309","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}
N. Hozumi, E. B. Prastika, Shafira Zahra, T. Kawashima, Y. Murakami
{"title":"Dual-domain Deconvolution Process Applied to Time-resolved Quantitative Dielectric Measurement","authors":"N. Hozumi, E. B. Prastika, Shafira Zahra, T. Kawashima, Y. Murakami","doi":"10.1109/ICD46958.2020.9341905","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341905","url":null,"abstract":"Deconvolution process is often applied to time-resolved dielectric measurements like the pulsed electroacoustic method. As the original signals, both target and reference signals, have acquired after being subjected to high pass filter, low frequency components have been significantly suppressed. It creates strong unnecessary low frequency components if the process has been done in frequency domain, leading to very uncomfortable bias noise in time domain. This presentation will propose an effective solution. It is proposed that combining the low frequency components deconvolved in time domain after being down-sampled and the high frequency components deconvolved in frequency domain gives a quick and precise signal. The process was embedded onto space charge measurement. Although a good signal was obtained even with only time-domain deconvolution, it was proved that the proposed method significantly improves its speed in calculation. As a conclusion dual-domain deconvolution process has been proposed and successfully applied to the space charge measurement without being disturbed by low frequency spurious.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"4 1","pages":"347-350"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84188064","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}
J. Hornak, O. Michal, P. Trnka, V. Mentlík, G. Vuity, O. Nouini, Z. A. Tamus
{"title":"Current and Voltage Response Measurements on Nanodielectrics","authors":"J. Hornak, O. Michal, P. Trnka, V. Mentlík, G. Vuity, O. Nouini, Z. A. Tamus","doi":"10.1109/ICD46958.2020.9341970","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341970","url":null,"abstract":"Dielectric materials are an essential part of all electrical devices. One of the reasons, their properties are studied, is that they are most impacted by internal and external influences during the lifetime of the electrical device. Composite materials are commonly used as a dielectric part, because of the synergy effect, when combining various components that have a positive impact to combat various these negative influences. In opposition to this, the composite material is commonly layered into thick tapes to meet device nominal voltage usage. This layering has a negative impact on some important material properties, such as dissipation factor or thermal conductivity. In recent years, using nanocomposites becomes an interesting way to improve composite materials and their reliability in electrical devices. This paper deals with the current and resorption characteristics of nanocomposite materials. These characteristics are important for understanding the influence of nanocomponent on the overall composite properties. Nanocomposite material used in this experiment was prepared by the Department of Technologies and Measurements and was consisted of epoxy resin and magnesium oxide nanoparticles. For the experiment, different values of filled nanocomposites were prepared (0, 1, 3, 5, 10, 20, 30 wt.% of MgO). Nanocomposites have been investigated by two research institutions. By this experiment, we confirmed our initial hypothesis that MgO positively influences the absorption and resorption characteristics to a certain level of filling.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"18 1","pages":"285-288"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87272843","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":"Variation in Charge Transport Behavior of Polypropylene/Elastomer Blends Exposed to Thermal Cycling","authors":"Zheng Song, Yu Gao, Jing Li, Jinjing Peng, B. Du","doi":"10.1109/ICD46958.2020.9341990","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341990","url":null,"abstract":"Polypropylene (PP) has great electrical insulation performance and is easy to recycle, which makes it a promising candidate for high voltage direct current (HVDC) cable insulation. The cable in real operation has to face both high and low temperatures which are originated from the change in current carrying capacity of cable conductor, which may bring variation in material structure of cable insulation thus influencing the electrical performance. In this work, isotactic polypropylene blended with different content polypropylene based elastomer (PBE) and ethylene octane elastomer (EOC) were prepared as test samples. The influence of the thermal cycling time on the micro-structure and charge trans port manner of the blend samples were discussed. Obtained results indicated that similar changes appeared on PP/PBE and PP/EOC blends with the increase of thermal cycling times. Only a small part of the PP/elastomer blends was oxidized and less carbonyl group was generated. The diameter of the PP/elastomer blends crystallization became smaller and a small amount of the shish-kebab crystal was formed, while the boundaries of spherulites and amorphous region were increased. The trap density and the trap depth increased, the carrier mobility increased, and DC breakdown strength dramatically decreased. It is suggested that the charge transport in PP/elastomer blends is accelerated due to the significant increase of shallow carrier trap caused by the thermal cycling aging.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"60 1","pages":"475-478"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86486200","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":"Capacitance Loss Analysis of Metallized Film Capacitors under AC Condition","authors":"Zheng Li, Hua Li, Fuchang Lin, Zhehao Wang, Guo‐fu Zhang, Liang Qi","doi":"10.1109/ICD46958.2020.9341882","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341882","url":null,"abstract":"With the rise of temperature and humidity, the electrode corrosion of metallized film capacitors under AC voltage becomes more significant. And the corresponding capacitance loss makes capacitors behave abnormally. This paper concentrates on the capacitance loss analysis of metallized film capacitors. Firstly, this paper establishes an experimental platform with a voltage of 305Vrms. The ambient temperature is 85°C, 60°C and 35°C, respectively. And the ambient humidity is 35%, 60%, and 85%, respectively. Secondly, the mechanism of capacitance loss is studied based on experiment results and the anatomical analysis of the capacitors. Finally, the capacitance loss of the metallized film capacitor with the effects of temperature and humidity is studied. The results indicate that: (1) The process of capacitance loss can be basically divided into 4 stages. Each stage corresponds to different mechanisms;(2) The duration of the moisture ingress process decreases as humidity rises or temperature decreases, while the capacitance loss is accelerated with the rise of temperature and humidity.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"14 1","pages":"173-176"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90481549","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}
Bingliang Shan, Yanyu Wu, Hanlin Song, Z. Xing, Meng Huang, Bai-xin Liu, Y. Lv, Chengrong Li
{"title":"Research on DC Breakdown Performance of Nanofluid-impregnated Pressboard Based on TiO2 Nanoparticles","authors":"Bingliang Shan, Yanyu Wu, Hanlin Song, Z. Xing, Meng Huang, Bai-xin Liu, Y. Lv, Chengrong Li","doi":"10.1109/ICD46958.2020.9341992","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341992","url":null,"abstract":"UHVDC has been applied widely since it possesses technical advantages in transmission electric power in long distance and large capability, leading to the severe test for the insulation performance of converter transformer. Oil-impregnated pressboard (OP) is one of the key insulating components in converter transformer due to its high mechanical strength and dielectric property, and its electrical performance is strictly related to the phenomenon of space charge accumulation. Recent experiments have shown that the insulation nanofluid has attracted a great deal of attention due to its considerable dielectric performance. Meanwhile, TiO2 semiconductor nanoparticles are considered to be the best choice owing to their low dielectric loss induced and considerable modification effect. However, the relation among particle sizes, DC breakdown voltages and space charge characteristics of nanofluid-impregnated pressboard (NP) based on TiO2 nanoparticles remains largely uncertain, which limits the performance improvement of oil/pressboard insulating system. In this paper, the modification effect on DC breakdown strength of oil-impregnated pressboard based on TiO2 nanoparticles with various sizes has been investigated. Moreover, the accumulation characteristics of OP and NPs were also studied by use of Pulsed Electro Acoustic Method (PEA). According to the experimental results and analysis, the relation among particle sizes, DC breakdown performance and accumulation characteristics of space charge was clarified and a possible modification mechanism has been proposed.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"70 1","pages":"169-172"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90584601","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":"Electrical Insulation Properties of Nanocomposite Epoxy Resin and Application to Mica Insulation","authors":"T. Mabuchi, Yin Xiaohong","doi":"10.1109/ICD46958.2020.9341854","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341854","url":null,"abstract":"It is reported recently that nanocomposite made by adding nanofiller to thermosetting resin shows excellent insulation performance. In this study, we have examined the nanocomposite material composition effective for improvement of the insulation performance that can be applied to various kinds of high-voltage equipment. As a result, we have proved that both the dispersion property and the insulation characteristics are improved when a silane coupling agent having chemical reactivity with matrix resin is applied on the nanofiller surface. We have also proved that nanofiller is sufficiently permeated into mica tape and the insulation lifetime of mica nanocomposite is improved significantly.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"4 1","pages":"241-244"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89824855","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}
Bhagya Swarnasinghe, Kavindya Dissanayake, Udathari Medagoda, J. Wijayakulasooriya, S. Kumara, M. Fernando
{"title":"Prony Algorithm for Noise Filteration in Partial Discharge Signals Captured by High Frequency Current Transducer","authors":"Bhagya Swarnasinghe, Kavindya Dissanayake, Udathari Medagoda, J. Wijayakulasooriya, S. Kumara, M. Fernando","doi":"10.1109/ICD46958.2020.9341965","DOIUrl":"https://doi.org/10.1109/ICD46958.2020.9341965","url":null,"abstract":"This paper presents application of Prony algorithm for de-nosing of partial discharge (PD) signals captured using a high frequency current transducer (HFCT). A laboratory setup was developed to generate individual and mixed PDs due to corona, surface and cavity type discharges. The generated PD signals were captured by HFCT inductive coupling method. Then Prony algorithm was utilized to de-noise the captured PD signals. PD signals from corona and surface discharges were exponentially varying single spikes but with different phase information indicating the ability of usage of first order Prony filter for denosing. On the contrary, the cavity PD signals were oscillatory shape and effectively get filtered by a third order filter. It was verified that a Prony algorithm based filter designed according to PD shape, can be used as an effective de-noising method for HFCT based PD detection in presence of multiple PD sources.","PeriodicalId":6795,"journal":{"name":"2020 IEEE 3rd International Conference on Dielectrics (ICD)","volume":"31 1","pages":"846-849"},"PeriodicalIF":0.0,"publicationDate":"2020-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88888423","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}