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 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 - 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 N2 - A new fluorescent polymer optical fibre sensor (F-POF) has been tested in combination with different single photon counting modules in real-scale model of a translucent high voltage (HV) stress cone for the detection of inner partial discharges (PDs). In experiments with different artificial PD sources these sensors were capable to detect discharges with an apparent Charge down to the limit of a few hundred femto Coulombs even with an unfavorable sensor location. By combining the datasets of the electrical and optical PD measurement (coincidence window ±100 ns) it is possible to suppress background noise and to undoubtedly assign signals to real inner PD events. First results of an optical/optical coincident PD measurement (coincidence interval ±100 ns) including an AC phase-correlated filtering show several coincident photon counts in the ränge of 1-2 pC over the whole Observation interval, indicating the potential ofthis new alternative PD measurement and evaluation method. T2 - POF 2014 - 23nd International conference on plastic optical fibers CY - Hiyoshi, Yokohama, Japan DA - 08.10.2014 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 - 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 T1 - Sensitive optical detection of partial discharges in transparent and translucent silicone elastomers N2 - Dieser Beitrag gibt einen Überblick über den gesamten optischen Übertragungsweg vom Ursprung der Teilentladungen (TE) in Kabelgarnituren bis zur Visualisierung der TE-Messergebnisse mit einem modernen digitalen TE-Messsystem. Hierzu zählen die relevanten Materialeigenschaften der in Frage kommenden Silikonelastomere, die Verwendung fluoreszierender Lichtwellenleiter als potentialfreie Licht-Sensoren und deren minimalinvasive Integration in die hochspannungstechnische Umgebung, die hochempfindliche Wandlung optischer in elektrische Signale sowie Ansätze zur Optimierung dieser Komponenten bzw. Teilsysteme. N2 - This paper deals with optical PD detection in cable accessories containing stress cones made of Silicon elastomer. It provides a survey on the optical and electrical PD propagation path from source to detection. This includes relevant material properties of possibly suited silicone elastomers, the use of fluorescent optical fibers for PD light detection, the minimally invasive integration into HV areas, high-sensitive optical-electrical signal conversion and concepts for optimization. T2 - 6. Fachtagung Diagnostik elektrischer Betriebsmittel CY - Berlin, Germany DA - 25.11.2014 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 - 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 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 - Heidmann, G. A1 - Habel, Wolfgang T1 - Fibre-optic acoustic emission sensors for high voltage environments N2 - This contribution introduces ultrasonic fibreoptic sensors that were originally designed for detecting degradative processes in elastomeric insulations of high voltage cable accessories. This application requires sensor performance comparable to the most sensitive conventional piezoelectric acoustic emission sensors, however adding demanding constraints imposed by the high voltage environment. The sensors developed with this speciftc application in mind may, however, find uses also in different areas of testing and monitoring, where the presence of strong magnetic or electromagnetic ftelds prevent the use of conventional acoustic emission sensors. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 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 - 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 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 - 02.06.2014 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 EP - 91571J-4 AN - OPUS4-32444 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 T1 - Improved fibre-optic acoustic partial discharge sensors for elastomeric insulations N2 - Von uns entwickelte faseroptisch-akustische Sensoren wurden an Modellen für innere Teilentladungen (TE) in Silikonelastomer- Isolierungen erprobt. Bei 32 mm Abstand zu einer eingebetteten TE-Quelle wurde eine äquivalente Empfindlichkeit im Bereich weniger Picocoulomb scheinbarer Ladung erreicht. In einem Versuchsaufbau mit künstlicher TEQuelle, der durch Geometrie und Material ein Hochspannung-Aufschiebeelement simuliert, wurde bei akustisch gewollt ungünstiger Sensorplatzierung ein TE-Detektionslimit von 35 pC scheinbarer Ladung ermittelt. Neben der Leistungsfähigkeit der vorgestellten Sensoren in Bezug auf die Detektion von Wechselspannungs-TE wurde auch ihre Fähigkeit geprüft, Gleichspannungs-TE im elastomeren Isolierstoff zu detektieren. Dabei hat sich gezeigt, dass die akustische Methode bei Gleichspannung ein unerwartet empfindliches Werkzeug zum Aufspüren TE-behafteter Fehlstellen sein kann. N2 - Fibre-optic acoustic sensors developed by us for the detection of partial discharge (PD) in silicone elastomer insulation were tested using artificial embedded sources of PD. Few-Picocoulomb sensitivity was shown for a Separation of 32 mm between PD source and sensor. Additionally, sensor detectivity was investigated on a Setup simulating geometry and material of a real-scale push-on high voltage stress cone. An intentionally unfavourably placed sensor showed an equivalent detection limit of 35 pC apparent Charge. Besides testing sensing performance with respect to AC-PD, also the acoustic detection DC-PD in elastomeric insulation was investigated. This lead to the observation that the acoustic method is an unexpectedly sensitive tool for detecting PD -inducing defects in such materials under DC stress. T2 - 6. ETG-Fachtagung - Diagnostik elektrischer Betriebsmittel 2014 CY - Berlin, Germany DA - 25.11.2014 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 - 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 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 - 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 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 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Siebler, Daniel A1 - Habel, Wolfgang T1 - Faseroptische Sensoren zur akustischen Detektion von Teilentladungen in hochspannungstechnischen Anlagen und Betriebsmitteln T1 - Fibre optic sensors for the detection of partial discharge in high voltage facilities and equipment 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. N2 - Conventional methods for the detection of partial discharge (PD) in high voltage devices and equipment require electromagnetically quiet conditions of measurement and hence are not unproblematic in testing operational equipment under typical conditions encountered in a high voltage plant. Therefore, non-conventional, electromagnetic (HF, VHF, UHF), and acoustic methods find increasing use in field testing and monitoring. Additionally, because of their inherent immunity against electromagnetic interference, fibre-optic methods for detecting PD are being tested. This paper introduces two types of acoustic fibre-optic sensors (a-FOS) and reports on tests of their ability to detect PD in elastomeric insulations such as silicone stress cones used in cable accessories. The laboratory results presented here show that sensitivities can be reached which are sufficient for the detection of critically intense PD, for example in cable accessories. Based on this the potential of fibre-optic acoustic detection of PD in the condition monitoring of high voltage Equipment is discussed, also for the case of a scheme combining a-FOS with fibre-coupled optical sensors. T2 - Diagnostik elektrischer Betriebsmittel CY - Fulda, Germany DA - 15.11.2012 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 - 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 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 - 15.10.2012 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 EP - 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 -