TY - CONF A1 - Rohwetter, Philipp A1 - Kielau, T. A1 - Lothongkam, Chaiyaporn A1 - Heidmann, G. A1 - Habel, Wolfgang ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - All fibre-optic simultaneous detection of optical and acoustic emission from partial discharges in silicone elastomer T2 - OFS2012 - 22nd International conference on optical fiber sensors (Proceedings) N2 - In high-voltage facilities of power stations and transmission networks, discharge activities leading to catastrophic failure can occur. Early detection of partial discharges (PD) in polymeric insulations of HV cable terminations and joints is therefore increasingly important. This paper describes a monitoring methodology to detect PD activity in silicone elastomer by two independent fibre-optic sensor types. Fluorescent fibre-based sensors are sensitive to plasma optical emission already at the onset of PD while an acoustic fibre-optic sensor responds to acoustic emission from the PD during its progression. The sensitivities of both sensor types are compared, and it is demonstrated that they provide complementary information for fibre-optic sensor-based monitoring of high-voltage cable accessories.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 2012-10-15 KW - Fiber optic sensors KW - Plasma KW - Sensors KW - Fibre-optic condition monitoring KW - Partial discharge KW - Acoustic emission KW - High-voltage breakdown KW - Silicone elastomer KW - Stress cone KW - Fluorescent fibre KW - High voltage cable accessories PY - 2012 DO - https://doi.org/10.1117/12.974941 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 8421B9-1 - 8421B9-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-27323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lothongkam, Chaiyaporn A1 - Habel, Wolfgang A1 - Heidmann, G. A1 - Gockenbach, E. T1 - Development of a new methodology to measure dielectric strength of elastomeric materials T2 - The 18th International Symposium on High Voltage Engineering T2 - The 18th International Symposium on High Voltage Engineering CY - Seoul, South Korea DA - 2013-08-25 PY - 2013 AN - OPUS4-29975 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lothongkam, Chaiyaporn A1 - Rohwetter, Philipp A1 - Habel, Wolfgang A1 - Gockenbach, E. T1 - Dielectric strength behavior and mechanical properties of transparent silicone rubbers for HV cable accessories T2 - ISEIM 2014 - 7th International symposium on electrical insulating materials (Proceedings) N2 - Modern optical partial discharge (PD) detection system based on fiber-optic sensors for PD on-line health monitoring in high-voltage (HV) cable terminations necessarily requires optically transparent or translucent insulation materials. The optically compatible silicone rubbers are the key to facilitate such innovative technology. In this work, AC 50 Hz dielectric strength Eb and mechanical properties of three types of commercially available silicone rubbers have been investigated. The investigations revealed that the translucent silicone rubber has a good mechanical performance but its Eb value is considered too low. However it is sufficiently good for use as base material for rubber stress cones. Unfortunately, its optical transmittance is poor compared to optically clear transparent silicones. On the other hand, the mechanical properties of transparent silicone rubbers do not comply with those demanded from push-on stress cones. In particular, their elongation at break is considered too low for that application. However they provide the Eb values of about 28 kV/mm to 29 kV/mm at 0.5 mm thickness, which are higher than those of the translucent type. Moreover, it was found that the post-curing process does not provide a positive impact on the ultimate elongation of silicone rubbers. T2 - ISEIM 2014 - 7th International symposium on electrical insulating materials CY - Niigata City, Japan DA - 01.06.2014 KW - Silicone rubbers KW - Dielectric strength KW - Tensile strength KW - Elongation at break KW - Rubber stress cone PY - 2014 DO - https://doi.org/10.1109/ISEIM.2014.6870829 SP - 503 EP - 506 PB - IEEE AN - OPUS4-32649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Lothongkam, Chaiyaporn T1 - Dielectric strength behaviour and mechanical properties of transparent insulation materials suitable to optical monitoring of partial discharges N2 - Eine neue Methode zur optischen Detektion von Teilentladungen in Hoch- und Höchstspannungs- Kabelgarnituren wird vorgeschlagen. Optische Fasern, integriert in die Hochspannungseinrichtung, können hochempfindlich messen und sind gegenüber elektromagnetischen Feldern immun. Sie ermöglichen somit ein Online-Monitoring in Bereichen hoher elektromagnetischer Felder. Diese optische Detektionsmethode kann in transparenten Silikonelastomer-Isolierstoffen, die sowohl dielektrische als auch mechanische Anforderungen erfüllen und für moderne Feldsteuerteile zum Einsatz kommen, zur Früherkennung von Teilentladungen genutzt werden. In dieser Arbeit werden das dielektrische Festigkeitsverhalten und die mechanischen Eigenschaften dreier kommerziell verfügbarer Silikonelastomere unter Wechselspannungsbeanspruchung untersucht. Ein Silikonmaterial war transluzent, zwei andere waren transparent, jedoch mit unterschiedlichen Vernetzungsbedingungen. Die Messung der Reißdehnung bzw. Zugfestigkeit erfolgte gemäß Standard ISO 37. Zur Untersuchung der dielektrischen Festigkeit Eb der unmodifizierten und modifizierten Silikonelastomere wurde eine neue Untersuchungsmethodik entwickelt. Gegenüber bisherigen Methodiken erlaubt dieses Prüfverfahren Untersuchungen mit geringem Materialverbrauch bei minimalem Zeitaufwand und ist gleichermaßen zuverlässig und effizient. Kernstück dieses Untersuchungsverfahrens ist eine speziell entwickelte Prüfeinrichtung. Darüber hinaus ermöglicht diese Prüfmethode eine einfache Präparation und Handhabung hochwertiger Prüflinge. Diese sowohl technischen als auch ökonomischen Vorteile können bei der Bestimmung des für Silikonelastomere wichtigen Wertes der elektrischen Festigkeit Eb ausgenutzt werden. Wegen der kostensparenden Prüfmethodik kann diese Prüfeinrichtung auch vorteilhaft für statistische Untersuchungen in Laboratorien eingesetzt werden. Die Untersuchungsergebnisse werden mittels Weibull- Verteilung statistisch analysiert und bewertet. Die Untersuchungen zeigten, dass das transluzente unmodifizierte Silikonelastomer einen großen Elastizitätsbereich mit akzeptabler plastischer Deformation besitzt; für Prüflinge mit einer Dicke von 0,5 mm wurde für 50 Hz Wechselspannung eine dielektrische Festigkeit von annähernd 24 kV/mm gemessen. Diese Festigkeitseigenschaften des transluzenten Silikonelastomers lässt die Schlussfolgerung zu, dass dieses Material die gegenwärtig für Feldsteuerteile in Hochspannungsgarnituren genutzten lichtundurchlässigen Elastomere ersetzen können. Die Lichtdurchlässigkeit des transluzenten Materials ist allerdings gering im Vergleich zu optisch klaren (transparenten) Silikonelastomeren. Andererseits erfüllen die mechanischen Eigenschaften der unmodifizierten transparenten Silikonelastomere nicht die Anforderungen, die an Aufschiebe-Feldsteuerteile gestelltwerden; ihre Reißdehnung wird als zu gering eingeschätzt. Sie erreichen jedoch einen Wert für die Wechselspannungsfestigkeit von 28 kV/mm bzw. 29 kV/mm (0,5 mm Probendicke), der höher ist, als der für den transluzenten Typ. Es wurde des Weiteren herausgefunden, dass ein Nachvernetzen der Silikonelastomere keinen positiven Einfluss auf ihre Reißdehnung hat. Aus diesem Grund muss die Reißdehnung unmodifizierter transparenter Silikonelastomere verbessert werden, bevor sie als Isoliermaterial in Feldsteuerteilen verwendet werden können. Zusätzlich wurde auch in der Arbeit der Einfluss der Dehnungsbeanspruchung auf die dielektrische Festigkeit unmodifizierter transluzenter Silikonelastomere untersucht. Es konnte gezeigt werden, dass eine Dehnungsbeanspruchung derartiger Silikonelastomere die dielektrische Festigkeit nicht negativ beeinflusst; diese Materialien können somit unter kombinierter mechanischer und elektrischer Beanspruchung eingesetzt werden. Neben der Verbesserung der optischen Teilentladungsdetektion in transluzenten Silikonelastomer- Isolierstoffen wurde auch der Einfluss ihrer Modifikation mit Fluoreszenzfarbstoffen untersucht. Die Ergebnisse zeigen, dass das Modifizieren transluzenter Silikonpolymere mit 0,02 Gew.-% kommerziell erhältlicher Fluoreszenzfarbstoffe die dielektrische Festigkeit dieser Werkstoffe nicht negativ beeinflusst. Somit eignet sich ein optisch kompatibles Silikonelastomer sehr gut für die Herstellung neuartiger fluoreszierender Silikonfasern, die dann in modifizierte transparente Silikonelastomer-Aufschiebekörper für Hochspannungskabel-Endverschlüsse zum Zwecke der Teilentladungsdetektion integriert werden können. Im Ergebnis der Untersuchungen können experimentell verifizierte Empfehlungen für die Revision des IEC- Standards 60243-1 gegeben werden, insbesondere für die Bestimmung der Wechselspannungsfestigkeit von Silikonelastomeren. Empfehlungen für weiterzuführende Untersuchungen werden im abschließenden Kapitel dieser Arbeit gegeben. N2 - A novel optical detection method for partial discharge in HV/EHV cable terminations has been proposed. Optical sensor fibres integrated into the HV equipment provide high sensitivity as well as immunity to electromagnetic interference and enable therefore on-line monitoring in electromagnetically noisy environment. The availability of optically transparent silicone rubbers that meet strict dielectric and mechanical criteria is a crucial prerequisite for the implementation of this method. The optically transparent silicone rubbers can be applied for the fabrication of a modern rubber stress cone as well as for the development of a new optical sensing element sensitive to PD activities. In this thesis, AC dielectric strength behaviour and mechanical properties of three types of commercially available silicone rubbers were investigated. One of the characterized silicone rubbers was a translucent type whereas the two others were optically transparent types, however with different chemical curing reactions. The measurements of tensile strength and elongation at break were carried out according to the ISO 37 standard. For investigation of the dielectric strength Eb behaviour of the virgin and modified silicone rubbers, a new methodology was developed. It is, at the same time, highly reliable and efficient, saves time and reduces material consumption in comparison to previously reported methodologies. The key component of this methodology is a specifically developed test facility. Furthermore, the methodology comprises determinations for easy preparation and handling of high-quality test specimens. This test method provides various advantages over other methods that have previously been used for measurement of the fundamental quantity Eb value of silicone rubbers. Both technical and economic demands are satisfied. The new facility also enables cost-effective routine tests in material research laboratories. The high quality of the obtained test results was verified by statistical analysis based on the 2-parameter Weibull distribution function. The investigations revealed that the virgin translucent silicone rubber has a large elastic region with an acceptable plastic deformation and also provides an AC 50 Hz dielectric strength of approximately 24 kV/mm for 0.5 mm thickness. These values enable considering the tested translucent silicone as replacement material for an opaque elastomer that is currently used for a rubber stress cone of HV cable accessories Unfortunately, its optical transmittance is poor compared to optically clear transparent silicone rubbers. On the other hand, the mechanical properties of virgin transparent silicone rubbers do not comply with those demanded from push-on stress cones. In particular, their elongation at break is considered too low for that application. However they provide the AC dielectric strength values in either 28 kV/mm or 29 kV/mm for 0.5 mm thickness, which are higher than those of the translucent type. Moreover, it was found that the post-curing process does not provide a positive impact on the ultimate elongation of silicone rubbers. Hence, the elongation at break of virgin transparent silicone rubbers must be improved before they can be used as insulating material for a rubber stress cone. In addition, the influence of mechanical tensile stress on the dielectric strength of the virgin translucent silicone rubber was investigated. The results show that mechanical tensile stress does not negatively influence on dielectric strength of such silicone rubber, so it can be well-operated under combined electrical and mechanical stresses. Beside the improvement of optical PD detection performance in the translucent silicone insulation materials, the influence of fluorescent dye’s modification was investigated. The results indicate that the commercially available fluorescent dyes of 0.02 wt. % mixed into the translucent silicone polymer do not negatively influence on the Eb value of such silicone material. So an optically compatible silicone rubber is perfectly suitable for the fabrication of novel fluorescent silicone optical fibres, which can be integrated into the modified transparent rubber stress cones of HV cable terminations. The final outcomes of this investigation are experimentally substantiated recommendations for future revision of IEC 60243-1, especially the chapter dealing with the determination of AC dielectric strength of silicone rubbers. Recommendations and suggestions for further investigations are addressed in the final chapter of this thesis. T3 - BAM Dissertationsreihe - 120 KW - Silicone rubber KW - tensile strength KW - dielectric strength KW - IEC 60243-1 KW - fluorescent silicone rubber KW - elongation at break KW - Weibull distribution KW - dielectric breakdown test PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-381 SN - 978-3-9816380-9-7 SN - 1613-4249 VL - 120 SP - 1 EP - 185 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-38 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Siebler, Daniel A1 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Habel, Wolfgang A1 - Heidmann, G. A1 - Vaterrodt, K. A1 - Leistner, A. A1 - Leistner, A. A1 - Pepper, D. A1 - Brusenbach, R. A1 - Plath, R. T1 - Empfindliche optische Detektion von Teilentladungen in transparenten und transluzenten Silikonelastomeren T2 - 6. Fachtagung Diagnostik elektrischer Betriebsmittel T2 - 6. Fachtagung Diagnostik elektrischer Betriebsmittel CY - Berlin, Germany DA - 2014-11-25 KW - Optische Teilentladungsdetektion KW - Transparente Silikonelastomere KW - Elektrische Betriebsmittel PY - 2014 SN - 978-3-8007-3648-5 SP - 1 EP - 5(?) PB - VDE Verlag GmbH AN - OPUS4-32532 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Siebler, Daniel A1 - Habel, Wolfgang T1 - Faseroptische Sensoren zur akustischen Detektion von Teilentladungen in hochspannungstechnischen Anlagen und Betriebsmitteln T2 - Diagnostik elektrischer Betriebsmittel 2012 N2 - Konventionelle elektrische Verfahren zur Erfassung von Teilentladungen (TE) in hochspannungstechnischen Bauteilen und Betriebsmitteln erfordern elektromagnetisch ungestörte Messbedingungen und sind für die Überprüfung von Anla-gen während des laufenden Betriebs nicht unproblematisch. Daher werden für Prüfung und Überwachung im Feld zu-nehmend unkonventionelle elektromagnetische (HF, VHF, UHF) und akustische Detektionsverfahren eingesetzt. Wegen ihrer prinzipiellen Immunität gegen elektromagnetische Störungen sind darüber hinaus faseroptische Verfahren der TE-Detektion in Erprobung. Im vorliegenden Beitrag werden zwei Typen akustisch-faseroptischer Sensoren (a-FOS) vorgestellt und auf ihre Eignung untersucht, Teilentladungen in elastomeren Isolierkörpern, wie etwa Silikon-Feldsteuerelementen von Kabelgarnituren, zu detektieren. Die hier präsentierten Laborergebnisse zeigen, dass die zur Detektion von TE mit kritischer Intensität (z.B. in Kabelgarnituren) notwendige Empfindlichkeit erreicht werden kann. Darauf basierend wird das Potential der faseroptisch-akustischen Detektion von TE in der hochspannungstechnischen Zustandsüberwachung allein und in Kombination mit fasergekoppelten fluoreszenzoptischen Sensoren diskutiert. T2 - Diagnostik elektrischer Betriebsmittel CY - Fulda, Germany DA - 2012-11-15 PY - 2012 UR - http://www.vde-verlag.de/proceedings-de/453465075.html SN - 978-3-8007-3465-8 SP - 1 EP - 6(?) PB - VDE Verlag GmbH AN - OPUS4-27391 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Heidmann, G. A1 - Habel, Wolfgang T1 - Fibre-optic acoustic emission sensors for high voltage environments T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 2014-09-24 PY - 2014 SN - 978-3-00-046740-0 SP - 122 EP - 123 AN - OPUS4-32460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Buchholz, Uwe A1 - Heidmann, G. A1 - Höhse, Marek A1 - Lothongkam, Chaiyaporn T1 - Fibre-optic sensors for early damage detection in plastic insulations of high-voltage facilities T2 - ISH 2011 - 17th International symposium on high voltage engineering N2 - Fibre-optic sensors (FOS) have great potential as online damage detectors when integrated in HV accessories. Among their well-known use as temperature and strain sensors, there are some more opportunities of use, e. g. they can intimately be embedded in polymeric insulations of HV cable terminations and joints to detect and monitor partial discharges right at the location of their origin. Two FOS types for early PD detection were investigated: an embeddable fibre-optic acoustic sensor to measure acoustlc waves in polymeric insulations generated by PDs, and a fluorescent optical fibre to detect first optical effects during ionization processes in the insulation material. The paper descrlbes these methods, related monitoring Problems and shows first test results. T2 - ISH 2011 - 17th International symposium on high voltage engineering CY - Hannover, Germany DA - 22.08.2011 KW - Fibre optic sensors KW - Monitoring KW - Materials behavior KW - Early shrinkage of cement paste PY - 2011 SN - 978-3-8007-3364-4 SP - 2070 EP - 2075 PB - VDE Verlag GmbH AN - OPUS4-24270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Siebler, Daniel A1 - Lothongkam, Chaiyaporn A1 - Rohwetter, Philipp A1 - Habel, Wolfgang A1 - Heidmann, G. T1 - Fluorescent fiber optical partial discharge sensor in high-voltage cable facilities T2 - POF 2013 - 22nd International conference on plastic optical fibers (Proceedings) N2 - New sensors for the detection of partial discharges (PDs) in high-voltage (HV) cable accessories are being de-veloped consisting of a fluorescent polymer optical fiber (F-POF) as sensing element. Depending on the fiber material F-POFs can be attached to and even integrated into the translucent silicone rubber insulation of HV cable terminations. As the embedment into the insulation material plays an important role, the sensor should not weaken the dielectric strength of the insulation material and should not be the origin of PD incidents. A sensor consisting of a commercial F-POF has been tested in the high-voltage lab regarding its PD detection ability un-der AC in comparison to a conventional electrical sensor. New silicone rubber F-POF (Si-F-POF) fiber models functionalized with coumarin dyes have been produced. The optical properties of these dye functionalized silox-anes are presented. These potential sensor fibers are highly flexible and might be embeddable at medium to high-voltage level. An additional way to further improve the level of PD light detection is to modify the translucent type of silicone rubber used in HV cable accessories in terms of optical transparency. In this context we present our first results of the optical and mechanical properties of new elastomeric transparent silicone materials specif-ically designed for the application as HV insulation materials in stress cones. T2 - POF 2013 - 22nd International conference on plastic optical fibers CY - Búzios, Rio de Janeiro, Brazil DA - 11.09.2013 KW - Polymer optical fiber KW - Fluorescence sensor KW - Partial discharge monitoring KW - High-voltage power cable KW - Silicone rubber KW - Fluorescence dye KW - Nanoparticles PY - 2013 SP - 322 EP - 327 CY - Rio de Janeiro, Brazil AN - OPUS4-30266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Habel, Wolfgang A1 - Heidmann, G. A1 - Pepper, D. ED - López-Higuera, J.M. ED - Jones, J. ED - López-Amo, M. ED - Santos, J.L. T1 - Improved fibre-optic acoustic sensors for partial discharge in elastomeric insulations T2 - OFS2014 - 23rd International conference on optical fibre sensors (Proceedings) N2 - Partial discharge in elastomeric high voltage insulations is a major reason for device failure. The special challenges of the high voltage environment limit the use of conventional acoustic emission sensors. Fibre-optic sensors can cope with these challenges thanks to their optical sensing principle and the use of all-dielectric materials. In this contribution, improvements to a previously introduced design of ultrasonic fibre-optic acoustic partial discharge sensors for elastomeric insulations are presented. The improved performance of fibre-optic acoustic sensors in detecting AC partial discharge is demonstrated. Furthermore, their ability to detect low-level damage processes in elastomeric insulation under DC dielectric stress is shown to outperform the highly sensitive electrical detection method. T2 - OFS2014 - 23rd International conference on optical fibre sensors CY - Santander, Spain DA - 2014-06-02 KW - Partial discharge KW - Acoustic emission KW - Dielectric ageing KW - Silicone elastomer KW - Stress cone KW - High voltage cable accessories PY - 2014 DO - https://doi.org/10.1117/12.2059489 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 9157 SP - 91571J-1 - 91571J-4 AN - OPUS4-32444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Siebler, Daniel A1 - Rohwetter, Philipp A1 - Brusenbach, R. A1 - Lothongkam, Chaiyaporn A1 - Heidmann, G. A1 - Leistner, A. A1 - Plath, R. T1 - Sensitivity-enhanced detection of partial discharge in cable accessories using fluorescent polymer optical fibre-sensor T2 - POF 2014 - 23nd International conference on plastic optical fibers (Proceedings) T2 - POF 2014 - 23nd International conference on plastic optical fibers CY - Hiyoshi, Yokohama, Japan DA - 2014-10-08 KW - Polymer optical fibre KW - Partial discharge sensor KW - Fkuorescence KW - High voltage facility PY - 2014 SP - 1 EP - 5(?) AN - OPUS4-32531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lothongkam, Chaiyaporn A1 - Siebler, Daniel A1 - Heidmann, G. A1 - Plath, R. A1 - Gockenbach, E. T1 - The influence of thermal aging on AC dielectric strength of transparent silicone rubbers for HV insulation T2 - ISEIM 2014 - 7th International symposium on electrical insulating materials (Proceedings) N2 - Optical methods and monitoring systems for the PD detection in GIS, GIL and oil-immersed type transformers have been demonstrated. Very recently these methods have been extended to the detection of PDs in solid insulation materials of cable accessories. This novel application in high-voltage (HV) cable terminations consists of integrated fiber-optic sensor which requires transparent insulation materials. Therefore, transparent silicone rubbers are considered as replacement material for currently used opaque elastomeric insulation material in stress cones of HV cable accessories. For this purpose a preliminary study on the long-term stability of two commercially available fully transparent silicone rubbers was performed. Accelerated thermal aging tests were carried out for 4 hours up to 100 hours at 200 °C under a normal air atmosphere and normal atmospheric pressure. The impact of thermal aging on the AC dielectric strength of the silicone samples was investigated and additionally the optical transmittance was determined using UV-Vis spectrophotometer. The investigation indicated that the dielectric strength value of the silicone samples was seriously reduced for long-term exposures to elevated temperatures. In addition, the UV-visible transmittance of thermally aged silicone samples was also decreased. The influence of these phenomena must be taken into account for the design of HV insulation materials, particularly under extremely high temperature operating conditions. T2 - ISEIM 2014 - 7th International symposium on electrical insulating materials CY - Niigata City, Japan DA - 01.06.2014 KW - AC dielectric strength KW - Thermal aging KW - Silicone elastomer KW - HV insulation KW - Silicone rubbers KW - Optical transmittance KW - Rubber stress cone PY - 2014 DO - https://doi.org/10.1109/ISEIM.2014.6870790 SP - 346 EP - 349 PB - IEEE AN - OPUS4-32533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Habel, Wolfgang A1 - Heidmann, G. A1 - Pepper, D. T1 - Verbesserte faseroptisch-akustische Teilentladungssensoren für elastomere Isolierungen T2 - 6. ETG-Fachtagung - Diagnostik elektrischer Betriebsmittel 2014 T2 - 6. ETG-Fachtagung - Diagnostik elektrischer Betriebsmittel 2014 CY - Berlin, Germany DA - 2014-11-25 PY - 2014 SN - 978-3-8007-3648-5 SN - 0341-3934 N1 - Serientitel: ETG-Fachbericht – Series title: ETG-Fachbericht VL - 144 SP - 1 EP - 6(?) PB - VDE Verlag GmbH AN - OPUS4-32873 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -