Pub Date : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214597
J. Pihera, P. Kadlec, P. Prosr, R. Polanský, Tomáš Kroupa
The breakdown phenomena and determination of dielectric strength is one of the essential topics in the field of insulating materials for high-voltage applications. In the case of basic thermosetting plastics, including epoxy resins, dielectric breakdown analysis has been performed many times, and the mechanism of conducting channel formation is already well known. However, the situation becomes more complicated if other material components are combined with the base polymer. The application of composites in electrical insulation systems is currently becoming more common. Of all available electrical insulating types of composites, the attention is paid to sandwich composite in this contribution. Specifically, a sandwich structure, which is an interconnection of a heat-resistant thermoplastic (polyimide film) and a conventional thermoset for high-voltage applications (epoxy resin layer), is analyzed. Tested structures were prepared as the composition of each one of the three different types of polyimide films and always the same conventional epoxy resin which is cured at elevated temperature after the amine curing agent addition. In the case of performed testing of sandwich composites, the conductive channel is formed rapidly through the two polymer layers, which are very different in chemical structure. In addition, an interface is formed between the material layers when these layers are interconnected during the epoxy resin curing process, and the effect of this interface must also be considered in the analysis of dielectric breakdown. This contribution is focused primarily on visual description of differences in a breakdown that occurs when different polyimide films without or even with a certain surface treatment are tested. The values of dielectric strength determined by the dynamic method for tested structures are also mentioned. It appears that the choice of a suitable polyimide film can be quite significant in the sandwich structure of the electrical insulation system in terms of dielectric strength.
{"title":"Dielectric breakdown analysis of composites consisting of epoxy resin and polyimide film","authors":"J. Pihera, P. Kadlec, P. Prosr, R. Polanský, Tomáš Kroupa","doi":"10.1109/Diagnostika49114.2020.9214597","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214597","url":null,"abstract":"The breakdown phenomena and determination of dielectric strength is one of the essential topics in the field of insulating materials for high-voltage applications. In the case of basic thermosetting plastics, including epoxy resins, dielectric breakdown analysis has been performed many times, and the mechanism of conducting channel formation is already well known. However, the situation becomes more complicated if other material components are combined with the base polymer. The application of composites in electrical insulation systems is currently becoming more common. Of all available electrical insulating types of composites, the attention is paid to sandwich composite in this contribution. Specifically, a sandwich structure, which is an interconnection of a heat-resistant thermoplastic (polyimide film) and a conventional thermoset for high-voltage applications (epoxy resin layer), is analyzed. Tested structures were prepared as the composition of each one of the three different types of polyimide films and always the same conventional epoxy resin which is cured at elevated temperature after the amine curing agent addition. In the case of performed testing of sandwich composites, the conductive channel is formed rapidly through the two polymer layers, which are very different in chemical structure. In addition, an interface is formed between the material layers when these layers are interconnected during the epoxy resin curing process, and the effect of this interface must also be considered in the analysis of dielectric breakdown. This contribution is focused primarily on visual description of differences in a breakdown that occurs when different polyimide films without or even with a certain surface treatment are tested. The values of dielectric strength determined by the dynamic method for tested structures are also mentioned. It appears that the choice of a suitable polyimide film can be quite significant in the sandwich structure of the electrical insulation system in terms of dielectric strength.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"23 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133173827","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214759
H. M. Umran, Feipeng Wang, Yushuang He
The low surface charge stability of Biaxially Oriented Polypropylene (BOPP) film has resulted in its inability to satisfy advanced electrical requirements. In this work, physico-chemical surface modifications of the films were made to verify the effect of these modifications on its electrical properties. The chemical treatment was performed on BOPP films on single side by orthophosphoric acid (H3PO4) with various concentrations at 110 °C by 4 h. The Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and the Scanning Electron Microscopy (SEM) were utilized to identify the chemical bonding and surface morphology variations during the treatments, respectively. Electrical performance was evaluated by Dielectric Relaxation Spectroscopy (DRS) and Isothermal Surface-Potential Decay (ISPD). The results confirmed that the improved charge stability, lower surface energy, lower permittivity εr and dielectric loss tanδ with higher acid concentrations. Molecular Dynamics (MDs) simulation was conducted via 3D maps of total electron density (TED) and molecular electrostatic potential (MEP), HOMO-LUMO energy levels analysis and the Density of States (DOS) in order to clarify the mechanism behind. The results obtained from both investigation methods were highly identical in terms of the effect of (H3PO4) on the charge stability due to the formation of shallower electron traps as well as the influence of morphological differences resulting from surface treatment.
{"title":"Improved electrical performance of BOPP films by acidic treatment at an elevated temperature","authors":"H. M. Umran, Feipeng Wang, Yushuang He","doi":"10.1109/Diagnostika49114.2020.9214759","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214759","url":null,"abstract":"The low surface charge stability of Biaxially Oriented Polypropylene (BOPP) film has resulted in its inability to satisfy advanced electrical requirements. In this work, physico-chemical surface modifications of the films were made to verify the effect of these modifications on its electrical properties. The chemical treatment was performed on BOPP films on single side by orthophosphoric acid (H3PO4) with various concentrations at 110 °C by 4 h. The Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and the Scanning Electron Microscopy (SEM) were utilized to identify the chemical bonding and surface morphology variations during the treatments, respectively. Electrical performance was evaluated by Dielectric Relaxation Spectroscopy (DRS) and Isothermal Surface-Potential Decay (ISPD). The results confirmed that the improved charge stability, lower surface energy, lower permittivity εr and dielectric loss tanδ with higher acid concentrations. Molecular Dynamics (MDs) simulation was conducted via 3D maps of total electron density (TED) and molecular electrostatic potential (MEP), HOMO-LUMO energy levels analysis and the Density of States (DOS) in order to clarify the mechanism behind. The results obtained from both investigation methods were highly identical in terms of the effect of (H3PO4) on the charge stability due to the formation of shallower electron traps as well as the influence of morphological differences resulting from surface treatment.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115625422","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214715
Zhixian Zhang, Weigen Chen, J. Lei, Hongrui Gu
Extracting key information from OLTC (On-Load Tap-Changer) vibration signal which contain a lot of redundant information and noise is the premise to achieving precise OLTC state diagnosis. In this paper, a Wiener filter algorithm for OLTC vibration signal is designed to adaptively reduce noise in on-site application; then a method for extracting vibration signal envelopes based on the principle of diode envelope detection is designed to acquire envelope of OLTC vibration signal and current signal of OLTC drive motor. Finally, several key parameters were extracted from the envelopes to analyze the operating states of OLTC.
{"title":"Vibration Signal Processing and State Analysis Technology for On-Load Tap-Changer","authors":"Zhixian Zhang, Weigen Chen, J. Lei, Hongrui Gu","doi":"10.1109/Diagnostika49114.2020.9214715","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214715","url":null,"abstract":"Extracting key information from OLTC (On-Load Tap-Changer) vibration signal which contain a lot of redundant information and noise is the premise to achieving precise OLTC state diagnosis. In this paper, a Wiener filter algorithm for OLTC vibration signal is designed to adaptively reduce noise in on-site application; then a method for extracting vibration signal envelopes based on the principle of diode envelope detection is designed to acquire envelope of OLTC vibration signal and current signal of OLTC drive motor. Finally, several key parameters were extracted from the envelopes to analyze the operating states of OLTC.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114544177","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214768
Viktor Cefer, M. Kučera, M. Gutten, Peter Brnčal, R. Jarina
The article analyzes the diagnostics of a high-voltage power transformer by means of an acoustic camera. It is one of the basic diagnostics and monitoring of remote measurement and analysis of acoustic emission. The high-voltage power transformer generates acoustic emission, thanks to which we can analyze the operating and fault states of the device. The article shows the use of the acoustic camera for operational monitoring and diagnostics of its life through noise from the source of the transformer winding and the ferromagnetic core.
{"title":"Visualisation and Diagnostics of Acoustic Emission from Transformers","authors":"Viktor Cefer, M. Kučera, M. Gutten, Peter Brnčal, R. Jarina","doi":"10.1109/Diagnostika49114.2020.9214768","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214768","url":null,"abstract":"The article analyzes the diagnostics of a high-voltage power transformer by means of an acoustic camera. It is one of the basic diagnostics and monitoring of remote measurement and analysis of acoustic emission. The high-voltage power transformer generates acoustic emission, thanks to which we can analyze the operating and fault states of the device. The article shows the use of the acoustic camera for operational monitoring and diagnostics of its life through noise from the source of the transformer winding and the ferromagnetic core.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124792913","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214689
M. Šebok, M. Kučera, M. Kubiš, Patrik Beňo, M. Gutten, N. Valko
This article describes evaluation principles electronic components in ignition system by using with voltage, current and thermovision analysis. The first of article is focused on theoretical principles of activity of ignition system based on voltage behavior in time for the primary part winding of transformer. In the second part of article is experimental measurement by means of measurement of voltage waveforms and no-contact measurement of thermal field by thermovision camera. In the end of article is performed comparison of both methods and detected the same fault in the part of components of the measured equipment. Both diagnostic methods have certain limitations, as the high-voltage coils and spark plugs are housed in encapsulated metal containers. The biggest problem can occur with thermal imaging diagnostics. If the ignition system is completely inaccessible, it is only necessary to use diagnostics by measuring high-voltage and current pulses by connecting clamp probes.
{"title":"Thermal and voltage diagnostics of automotive ignition system","authors":"M. Šebok, M. Kučera, M. Kubiš, Patrik Beňo, M. Gutten, N. Valko","doi":"10.1109/Diagnostika49114.2020.9214689","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214689","url":null,"abstract":"This article describes evaluation principles electronic components in ignition system by using with voltage, current and thermovision analysis. The first of article is focused on theoretical principles of activity of ignition system based on voltage behavior in time for the primary part winding of transformer. In the second part of article is experimental measurement by means of measurement of voltage waveforms and no-contact measurement of thermal field by thermovision camera. In the end of article is performed comparison of both methods and detected the same fault in the part of components of the measured equipment. Both diagnostic methods have certain limitations, as the high-voltage coils and spark plugs are housed in encapsulated metal containers. The biggest problem can occur with thermal imaging diagnostics. If the ignition system is completely inaccessible, it is only necessary to use diagnostics by measuring high-voltage and current pulses by connecting clamp probes.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121966529","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214660
Zdeněk Bezděk
Cogebi, member of ELCIM Group, is a traditional producer of mica insulation materials. The presented work introduces a new VPI isolation system of the HV winding of large rotating electrical machines based on medium-viscosity one-component epoxy impregnation varnish with high reactivity and Cogemica glass backed VPI tape 609R containing no accelerator. Due to its technological properties and final dielectric parameters, this insulation system aspires to be an alternative to insulation systems based on epoxy-anhydride VPI varnishes and porous mica tapes with an accelerator. Although existing insulation systems of large HV windings are very good in all technical and technological aspects, the legislative regulations (REACH registration requirement) limit the use of some key components of the systems in the future.
{"title":"New VPI Insulation System of High Voltage Stator Windings of Large Rotating Electrical Machines Based on Cogemica VPI Tapes and One-component Epoxy Impregnation Varnish","authors":"Zdeněk Bezděk","doi":"10.1109/Diagnostika49114.2020.9214660","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214660","url":null,"abstract":"Cogebi, member of ELCIM Group, is a traditional producer of mica insulation materials. The presented work introduces a new VPI isolation system of the HV winding of large rotating electrical machines based on medium-viscosity one-component epoxy impregnation varnish with high reactivity and Cogemica glass backed VPI tape 609R containing no accelerator. Due to its technological properties and final dielectric parameters, this insulation system aspires to be an alternative to insulation systems based on epoxy-anhydride VPI varnishes and porous mica tapes with an accelerator. Although existing insulation systems of large HV windings are very good in all technical and technological aspects, the legislative regulations (REACH registration requirement) limit the use of some key components of the systems in the future.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133040034","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214714
M. Kubiš, M. Šebok, Patrik Beňo, M. Kučera, M. Gutten
Currently, the control circuits check the condition of electronic components mainly by monitoring voltage levels, calculating and estimating value limits during the diagnostic mode of the element. In this article, we will focus specifically on the ignition system. Specialized measurements were made on the proposed measurement systems by simulating faults by applying oil and gasoline between the electrodes and failing to make the ignition contact of the driver on the spark plug.
{"title":"Diagnostics of the ignition system for various fault conditions","authors":"M. Kubiš, M. Šebok, Patrik Beňo, M. Kučera, M. Gutten","doi":"10.1109/Diagnostika49114.2020.9214714","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214714","url":null,"abstract":"Currently, the control circuits check the condition of electronic components mainly by monitoring voltage levels, calculating and estimating value limits during the diagnostic mode of the element. In this article, we will focus specifically on the ignition system. Specialized measurements were made on the proposed measurement systems by simulating faults by applying oil and gasoline between the electrodes and failing to make the ignition contact of the driver on the spark plug.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133463240","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214769
M. Mužík, P. Trnka, J. Hornak, O. Michal, V. Mentlík
Natural oils with their price and environment-friendly behaviour are more used these days like insulation fluids in transformers. There are often based on eg. rapeseed, soy, sunflower etc. oils. Compatibility between new materials used in transformers needs to be further discussed. Few papers already describe the behaviour of insulating papers and materials like gaskets, varnishes or core steel with soy or corn oil. This paper describes the compatibility of cable ties and rubber-based gasket and part of transformer bushing. These materials were placed into insulation oils, in our case rapeseed oil-based and for comparison to mineral oil Nynas Lyra, and thermally aged in the oven for 2000 hours at 120 °C and 1000 hours at 140 °C. All polymers and oils were analysed before and after ageing. Properties as weight and dimensions change, hardness by Shore and permittivity, resistivity, dissipation factor, the viscosity of oils are discussed.
{"title":"Compatibility of polymer materials with natural-based insulation oils","authors":"M. Mužík, P. Trnka, J. Hornak, O. Michal, V. Mentlík","doi":"10.1109/Diagnostika49114.2020.9214769","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214769","url":null,"abstract":"Natural oils with their price and environment-friendly behaviour are more used these days like insulation fluids in transformers. There are often based on eg. rapeseed, soy, sunflower etc. oils. Compatibility between new materials used in transformers needs to be further discussed. Few papers already describe the behaviour of insulating papers and materials like gaskets, varnishes or core steel with soy or corn oil. This paper describes the compatibility of cable ties and rubber-based gasket and part of transformer bushing. These materials were placed into insulation oils, in our case rapeseed oil-based and for comparison to mineral oil Nynas Lyra, and thermally aged in the oven for 2000 hours at 120 °C and 1000 hours at 140 °C. All polymers and oils were analysed before and after ageing. Properties as weight and dimensions change, hardness by Shore and permittivity, resistivity, dissipation factor, the viscosity of oils are discussed.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123465776","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 : 2020-09-01DOI: 10.1109/diagnostika49114.2020.9214695
{"title":"[Title page]","authors":"","doi":"10.1109/diagnostika49114.2020.9214695","DOIUrl":"https://doi.org/10.1109/diagnostika49114.2020.9214695","url":null,"abstract":"","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121751496","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 : 2020-09-01DOI: 10.1109/Diagnostika49114.2020.9214665
P. Prosr, R. Polanský, J. Pihera, P. Kadlec, M. Hirman, Tereza Krejnická, O. Musil, J. Komarek, R. Pavlica
This paper is focused on the analysis of selected dielectric parameters stability under the conditions of selected accelerated climatic aging. This stability is analyzed for glass fiber reinforced composites with different thermosetting matrix suitable for the production of electrical insulating and also construction elements. Different types of thermosetting resins (epoxy and polyurethane resins) were chosen for the preparation of composites, which are the subject of the presented experiment. Tested composites were firstly characterized in the delivered state and then after the accelerated climatic aging. Important dielectric parameters were evaluated, which are the volume resistivity and the surface resistivity. Two different tests of accelerated climatic aging were realized. The first one was Temperature/humidity cyclic test, which consists of alternated intervals (i) under the temperature of 55 °C and the humidity of 93 %RH and (ii) under the temperature of 25 °C and the humidity of 97.5 %RH. The second one was Damp heat steady state test when samples were exposed to the temperature of 85 °C and the humidity of 85 %RH continuously for 1000 hours. Based on the measured data of resistivities, prospective materials were selected for further activities leading to the production of construction elements with also good electrical insulating properties and with their minimal affection by simulated climatic conditions.
{"title":"Effects of Accelerated Climatic Aging on Volume and Surface Resistivity of Glass Fiber Reinforced Thermoset Composites","authors":"P. Prosr, R. Polanský, J. Pihera, P. Kadlec, M. Hirman, Tereza Krejnická, O. Musil, J. Komarek, R. Pavlica","doi":"10.1109/Diagnostika49114.2020.9214665","DOIUrl":"https://doi.org/10.1109/Diagnostika49114.2020.9214665","url":null,"abstract":"This paper is focused on the analysis of selected dielectric parameters stability under the conditions of selected accelerated climatic aging. This stability is analyzed for glass fiber reinforced composites with different thermosetting matrix suitable for the production of electrical insulating and also construction elements. Different types of thermosetting resins (epoxy and polyurethane resins) were chosen for the preparation of composites, which are the subject of the presented experiment. Tested composites were firstly characterized in the delivered state and then after the accelerated climatic aging. Important dielectric parameters were evaluated, which are the volume resistivity and the surface resistivity. Two different tests of accelerated climatic aging were realized. The first one was Temperature/humidity cyclic test, which consists of alternated intervals (i) under the temperature of 55 °C and the humidity of 93 %RH and (ii) under the temperature of 25 °C and the humidity of 97.5 %RH. The second one was Damp heat steady state test when samples were exposed to the temperature of 85 °C and the humidity of 85 %RH continuously for 1000 hours. Based on the measured data of resistivities, prospective materials were selected for further activities leading to the production of construction elements with also good electrical insulating properties and with their minimal affection by simulated climatic conditions.","PeriodicalId":428555,"journal":{"name":"2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121769915","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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