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  • 1.
    Akbari, Saeed
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Kostov, Konstantin Stoychev
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Brinkfeldt, Klas
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Adolfsson, Erik
    RISE Research Institutes of Sweden, Material och produktion, Tillverkningsprocesser.
    Lim, Jang-Kwon
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Andersson, Dag
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Bakowski, Mietek
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Wang, Qin
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Salter, Michael
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Ceramic Additive Manufacturing Potential for Power Electronics Packaging2022Inngår i: IEEE Transactions on Components, Packaging, and Manufacturing Technology, ISSN 2156-3950, E-ISSN 2156-3985, Vol. 12, nr 11, s. 1857-1866Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Compared with silicon-based power devices, wide band gap (WBG) semiconductor devices operate at significantly higher power densities required in applications such as electric vehicles and more electric airplanes. This necessitates development of power electronics packages with enhanced thermal characteristics that fulfil the electrical insulation requirements. The present research investigates the feasibility of using ceramic additive manufacturing (AM), also known as three-dimensional (3D) printing, to address thermal and electrical requirements in packaging gallium nitride (GaN) based high-electron-mobility transistors (HEMTs). The goal is to exploit design freedom and manufacturing flexibility provided by ceramic AM to fabricate power device packages with a lower junction-to-ambient thermal resistance (<italic>R</italic>&#x03B8;JA). Ceramic AM also enables incorporation of intricate 3D features into the package structure in order to control the isolation distance between the package source and drain contact pads. Moreover, AM allows to fabricate different parts of the packaging assembly as a single structure to avoid high thermal resistance interfaces. For example, the ceramic package and the ceramic heatsink can be printed as a single part without any bonding layer. Thermal simulations under different thermal loading and cooling conditions show the improvement of thermal performance of the package fabricated by ceramic AM. If assisted by an efficient cooling strategy, the proposed package has the potential to reduce <italic>R</italic>&#x03B8;JA by up to 48%. The results of the preliminary efforts to fabricate the ceramic package by AM are presented, and the challenges that have to be overcome for further development of this manufacturing method are recognized and discussed. 

  • 2.
    Alfredsson, Hampus
    et al.
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Nyman, Joakim
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Nilsson, John
    Swedavia AB, Sweden.
    Staack, Ingo
    Linköping University, Sweden.
    Infrastructure modeling for large-scale introduction of electric aviation2022Inngår i: 35th International Electric Vehicle Symposium and Exhibition (EVS35), 2022Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the results of the MODELflyg research project funded by the Swedish Transport Administration to gain more knowledge about ground charging infrastructure demand for the electrification of air traffic. An integrated simulation model was developed including flight traffic data processing, modelling of battery electric aircraft performance, and charging simulations. Several different options are available to select specific air traffic flows of interest, including scheduling algorithms for electric aviation adapted timetables. Furthermore, a smart-charging algorithm was developed to lower peak power demand at each airport from simultaneous charging of multiple electric aircraft.

    Fulltekst (pdf)
    fulltext
  • 3.
    Andersson Ersman, Peter
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Freitag, Kathrin
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Nilsson, Marie
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Åhlin, Jessica
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Brooke, Robert
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Nordgren, Niklas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Aulin, Christian
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Nevo, Yuval
    Melodea Ltd, Israel.
    Beni, Valerio
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Electrochromic Displays Screen Printed on Transparent Nanocellulose-Based Substrates2023Inngår i: Advanced Photonics Research, ISSN 2699-9293, artikkel-id 2200012Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Manufacturing of electronic devices via printing techniques is often considered to be an environmentally friendly approach, partially due to the efficient utilization of materials. Traditionally, printed electronic components (e.g., sensors, transistors, and displays) are relying on flexible substrates based on plastic materials; this is especially true in electronic display applications where, most of the times, a transparent carrier is required in order to enable presentation of the display content. However, plastic-based substrates are often ruled out in end user scenarios striving toward sustainability. Paper substrates based on ordinary cellulose fibers can potentially replace plastic substrates, but the opaqueness limits the range of applications where they can be used. Herein, electrochromic displays that are manufactured, via screen printing, directly on state-of-the-art fully transparent substrates based on nanocellulose are presented. Several different nanocellulose-based substrates, based on either nanofibrillated or nanocrystalline cellulose, are manufactured and evaluated as substrates for the manufacturing of electrochromic displays, and the optical and electrical switching performances of the resulting display devices are reported and compared. The reported devices do not require the use of metals and/or transparent conductive oxides, thereby providing a sustainable all-printed electrochromic display technology.

  • 4.
    Andersson Ersman, Peter
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Åhlin, Jessica
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Westerberg, David
    RISE Research Institutes of Sweden.
    Sawatdee, Anurak
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Arvén, Patrik
    J2 Holding AB, Sweden.
    Ludvigsson, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Batteryless Electronic System Printed on Glass Substrate2021Inngår i: Electronic Materials, E-ISSN 2673-3978, Vol. 2, nr 4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Batteryless hybrid printed electronic systems manufactured on glass substrates are reported. The electronic system contains a sensor capable of detecting water, an electrochromic display, conductors, a silicon chip providing the power supply through energy harvesting of electromagnetic radiation, and a silicon-based microcontroller responsible for monitoring the sensor status and the subsequent update of the corresponding display segment. The silicon-based components were assembled on the glass substrate by using a pick and place equipment, while the remainder of the system was manufactured by screen printing. Many printed electronic components, often relying on organic materials, are sensitive to variations in environmental conditions, and the reported system paves the way for the creation of electronic sensor platforms on glass substrates for utilization in see-through applications in harsh conditions. Additionally, this generic hybrid printed electronic sensor system also demonstrates the ability to enable autonomous operation through energy harvesting in future smart window applications.

  • 5.
    Andersson, Kristina
    et al.
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Burden, Håkan
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Amanuel, Mahdere DW
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Stenberg, Susanne
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Thidevall, Niklas
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Fordonsdata till allmänhetens nytta - geofencing och affärsmodeller2021Rapport (Annet vitenskapelig)
    Abstract [sv]

    Fordonsdata kan i framtiden vara till stor nytta för myndigheter på olika sätt. Än så länge samlar myndigheter in fordonsdata i begränsad omfattning. Det kan t.ex. handla om att genom offentlig upphandling pröva nya sätt för att kontrollera kvaliteten på utförd snöröjning. Trots att det finns ett intresse från både privata och offentliga aktörer att genomföra affärer kring fordonsdata är det ändå svårt för marknaden att ta fart. 

    Frågan om hur fordonsdata kan kommersialiseras med offentliga aktörer som köpare har därför undersökts inom Drive Sweden Policy Lab i samarbete med CeViss-projektet (Cloud enhanced cooperative traffic safety using vehicle sensor data). CeViss-projektet har undersökt smarta kameror och hur de bl.a. kan användas för att varna andra förare för vilda djur vid vägen eller informera SOS Alarm om hur det ser ut vid en olycksplats. 

    Förutsättningarna för lyckad kommersialisering kan sammanfattas under tre rubriker - affären, tekniken och juridiken. Vi ser att affären ligger i förmåga att erbjuda aggregerade data där olika datamängder korsbefruktas och därmed skapar ett större värde än de ingående datamängderna besitter var för sig. Kommersiella aktörer pekar på att rollen att aggregera data, eller förädla den, är mest intressant, eftersom det innebär en möjlighet att utveckla tjänster. En sådan tjänst förutsätter tillgång till en säker uppkoppling och överföring. Det är också resurskrävande att förädla data och styra rätt överföring, liksom att se över, anpassa och ta fram avtal som gör korsbefruktning av data och överföring av rätt data juridiskt möjlig. Här spelar individens integritet kontra samhällets behov av data en stor roll. Det är inte heller klart vilket behov aktörer inom olika samhällssektorer har av fordonsdata, samt hur dessa kommer att få tag i fordonsdata. 

    Utmaningen för industrin ligger i att våga lita på att det finns en hållbar affär med myndigheten i längden, dvs. att det finns en tillräckligt stor betalningsvilja från samhällets sida även när data anses samhällskritisk viktigt. För att främja kommersialisering är det bra att börja med ett specifikt utvalt område för att utarbeta processer, avtal, tekniklösningar, affärs-modeller och så vidare. 

    Geofencing hade kunnat vara en möjlighet att skapa de avgränsningar som behövs för en första affär, samtidigt som det skulle skapa tydlighet om var och när data samlas in från fordon. En sådan avgränsning hade också kunnat tjäna som en regulatorisk sandlåda för att utvärdera möjligheten till avtal som är hållbara över tid, det vill säga där det är rimligt att inom vissa gränser använda data på nya sätt eller för nya syften. 

    Rapporten avslutas med en sammanställning av geofencing och datadelning ur ett juridiskt perspektiv samt en beskrivning av Drive Sweden Policy Lab. 

    Fulltekst (pdf)
    fulltext
  • 6.
    Axner, Ove
    et al.
    Umeå University, Sweden.
    Forssen, Clayton
    Umeå University, Sweden.
    Silander, Isak
    Umeå University, Sweden.
    Zakrisson, Johan
    Umeå University, Sweden.
    Zelan, Martin
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Ability of gas modulation to reduce the pickup of drifts in refractometry2021Inngår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 38, nr 8, s. 2419-2436Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Gas modulation refractometry (GAMOR) is a methodology for assessment of gas refractivity, molar density, and pressure that, by a rapid gas modulation, exhibits a reduced susceptibility to various types of disturbances. Although previously demonstrated experimentally, no detailed analysis of its ability to reduce the pickup of drifts has yet been given. This work provides an explication of to what extent modulated refractometry in general, and GAMOR in particular, can reduce drifts, predominantly those of the cavity lengths, gas leakages, and outgassing. It is indicated that the methodology is insensitive to the linear parts of so-called campaign-persistent drifts and that it has a significantly reduced susceptibility to others. This makes the methodology suitable for high-accuracy assessments and out-of-laboratory applications

  • 7.
    Belov, Ilia
    et al.
    Jönköping University, Sweden.
    Arwidson, Jonas
    Saab AB, Sweden.
    Poder, Ralf
    RISE - Research Institutes of Sweden.
    Johannesson, Pär
    RISE - Research Institutes of Sweden.
    Leisner, Peter
    RISE - Research Institutes of Sweden. Jönköping University, Sweden.
    Thermal fatigue prediction: consequences of cycle reduction and material property variation2016Inngår i: Electronic Environment, 2016, Vol. 1, s. 27-27Konferansepaper (Fagfellevurdert)
  • 8.
    Belov, Ilia
    et al.
    Jönköping University, Sweden.
    Lang, Jenny
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Hellén, Johan
    Saab AB, Sweden.
    Lim, Jang-Kwon
    RISE., Swedish ICT, Acreo.
    Schødt, Bo
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Nilsson, Torbjörn M. J.
    Saab AB, Sweden.
    Poder, Ralf
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Bakowski, Mietek
    RISE., Swedish ICT, Acreo.
    Leisner, Peter
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Reliability study of GaN HEMTs2016Konferansepaper (Annet vitenskapelig)
  • 9.
    Bergman, Anders
    RISE - Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Absolute calibration of a 100 KV DC divider1996Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An absolute determination of the ratio of a 100 kV DC divider has been made. A new Zener device that has recently become available has been used in a step-up mode to obtain the divider ratio. The uncertainty of the determination is 5.5 ppm.

  • 10.
    Bergman, Anders
    RISE - Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Achievable Accuracy in Industrial Measurement of Dissipation Factor of Power Capacitors2018Inngår i: NCSLI Measure, ISSN 1931-5775, Vol. 12, nr 1, s. 34-41Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Modern dielectrics used in power capacitors can exhibit a dissipation factor lower than 0.005 %, which approaches the limits of presently available measurement techniques. This article reviews techniques, apparatus, and available calibration services for dissipation factor with regard to lowest achievable uncertainties. It is shown that further metrological advances are necessary to lower uncertainty in the measurement to levels at least five times less than presently achievable, in order to ensure traceable and quality-assured measurement of modern dielectrics with such low dissipation factors

    Fulltekst (pdf)
    fulltext
  • 11.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik.
    Bergman, Allan
    RISE - Research Institutes of Sweden.
    Jönsson, Bengt
    ABB AB, Sweden.
    Rietveld, Gert
    VSL Nederlands Metrologisch Instituut, Netherlands.
    Sauzay, Mathieu
    JST transformateurs, France.
    Walmsley, Jonathan
    GE Power, UK.
    Sund, John Bjarne
    MSC EE Transformer Consultant, Norway.
    Estimating Uncertainty in Loss Measurement of Power Transformers2019Inngår i: ISH 2019, International Sympsoium on High Voltage Engineering, Budapest, Hungary, August 26-30, 2019., 2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Eco-design directive issued by the European Commission has led to re-quirements on efficiency of power transformers. In the case of large power transformers used in grid applications, serious problems are encountered in establishing how reliable the loss measurements are. An effort is currently on-going within IEC to produce a documentary standard on “Rules for the determination of uncertainties in the measurement of the losses of power transformers”. An IEC standard should be clear and easy to understand by all users in the industry. Background theory and material, whilst necessary for understanding, is not required for the day-to-day application of the standard. This paper presents a more detailed background and theory on the measure-ment of transformer losses and how to quantify precision. The authors are all members of the IEC maintenance team working with the standard.

    Fulltekst (pdf)
    fulltext
  • 12.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Bergman, Sixten
    Consultant, Rönnvägen 1 A, 507 71 Gånghester, Sweden.
    Hoffmann, Christian
    Baur Gmbh, Austria.
    Paulus, Eberhard
    Baur Gmbh, Austria.
    Elg, Alf Peter
    RISE - Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Traceable measurement of dielectric dissipation factor at Very Low Frequency2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Very Low Frequency (VLF) tests are often used for after-laying tests of power cables since the reactive power demand is much lower at VLF than at 50 Hz. In order to augment the usefulness of the test, it is often complemented by a measurement of dielectric dissipation factor (tan ), where the acceptance of the tested object is based on this measurement. A traceability chain for dissipation factor at high voltage and very low frequency has as yet not been recognized by the International Bureau of Weights and Measures (BIPM), which results in difficulties to prove the quality of the measurement. The measurement is complicated by the limited range of the current in the test object that can be resolved by available high voltage test equipment, thus limiting the possible choices of reference systems. A novel reference measuring system that can fulfil these needs has been developed at SP Technical Research Institute of Sweden in the capacity as National Measurement Institute. The traceability of the system to National Standards of Measurement is ensured by careful scientific work and analyses. This measuring system has the ability to measure dissipation factor at 0.1 Hz in the voltage range from 0.5 kV up to 50 kV with an uncertainty better than 0.004 %.

    Fulltekst (pdf)
    fulltext
  • 13.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Mätteknik.
    Rietveld, Gert
    VSL, Netherlands.
    Feasibility of direct measurement of HVDC converter station loss2019Inngår i: CIGRE Science & Engineering, ISSN 2426-1335, Vol. 15, s. 85-93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Losses of HVDC converter stations need to be accurately quantified to support evaluation of bids for such systems and to underpin efforts to reduce greenhouse gas emissions. At present, these losses are estimated, based on loss calculations for individual converter components, and no reliable method exists to measure the actual HVDC converter station loss as difference between power on the AC- and DC-side of the station. The necessary requirements for such a measurement are investigated in this study, and a tentative design of a suitable loss measuring setup is explored. This approach is a useful alternative for those cases where a direct measurement of losses via a temporary connection with two converters operating in back-to-back mode cannot be made.

    Fulltekst (pdf)
    fulltext
  • 14.
    Bisschop, Roeland
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Willstrand, Ola
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Amon, Francine
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Rosenggren, Max
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Fire Safety of Lithium-Ion Batteries in Road Vehicles2019Rapport (Annet vitenskapelig)
    Abstract [en]

    The demand for lithium-ion battery powered road vehicles continues to increase around the world. As more of these become operational across the globe, their involvement in traffic accidents and fire incidents is likely to rise. This can damage the lithium-ion battery and subsequently pose a threat to occupants and responders as well as those involved in post-crash operations. There are many different types of lithium-ion batteries, with different packaging and chemistries but also variations in how they are integrated into modern vehicles. To use lithium-ion batteries safely means to keep the cells within a defined voltage and temperature window. These limits can be exceeded as a result of crash or fault conditions. This report provides background information regarding lithium-ion batteries and battery pack integration in vehicles. Fire hazards are identified and means for preventing and controlling them are presented. The possibility of fixed fire suppression and detection systems in electric vehicles is discussed.

    Fulltekst (pdf)
    fulltext
  • 15.
    Borchling, Alexander
    et al.
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Kroner, Corinna
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Akselli, Basak
    Turkiye Bilimsel ve Teknolojik Arastirma, Turkey.
    Benková, Miroslava
    Cesky Metrologicky Institut, Czech Republic.
    Büker, Oliver
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Christoffersen, Nikki
    FORCE Technology, Denmark.
    Haack, Søren
    Teknologisk Institut Kongsvang, Denmark.
    Seypka, Veit
    DVGW - Technologiezentrum, Germany.
    Warnecke, Heiko
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Die Welt der Wasserzähler im Wandel2023Inngår i: GWF, Wasser - Abwasser, ISSN 0016-3651, Vol. 2023, nr 6, s. 89-93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Like everywhere else, time does not stand still for water meters. The requirements change, whether through technological progress, e.g., through the use of electronic meters, or changes in drinking water consumption. A revision of relevant normative documents is currently taking place at the international level. Against this background, various studies have been carried out in recent years and infrastructure has been built up with which the measurement behaviour of water meters can be examined more closely under real operating conditions, even at the laboratory level. This article presents the infrastructure. Furthermore, two current studies on the measurement behaviour of water meters are presented. In these studies, the effect of water quality and the effect of discrete measurements on the measurement accuracy of electronic water meters were investigated. 

  • 16. Brink, Jan-Olof
    et al.
    Klasson, Mikael
    Lundgren, Urban
    RISE Research Institutes of Sweden, Säkerhet och transport, Fordon och automatisering.
    Introduktion till EMC2017Bok (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    All elektronik stör eller störs av radiovågor och elektromagnetiska fält. EMC – elektromagnetisk kompatibilitet – handlar om förmågan hos en apparat eller utrustning att fungera i sin elektromagnetiska omgivning utan att orsaka oacceptabla störningar. EMC är ett komplext ämne som det råder stor okunskap om i vårt samhälle. Många gånger upptäcks brister i EMC sent i processen och medför då kostsamma förseningar och problem. Det är därför viktigt att man redan på ett tidigt stadium tar hänsyn till EMC-direktiv och följer de lagar och regler som finns. I Introduktion till EMC beskriver författarna ämnet på ett enkelt, övergripande och lättfattligt sätt. Innehållet är upplagt så att boken både kan användas som ett uppslagsverk och läsas i utbildnings­syfte. Introduktion till EMC är tänkt som en första introduktion till EMC-området och som läsare behöver du inte ha några speciella förkunskaper, endast en grundläggande förståelse för ellära.

  • 17.
    Büker, Oliver
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Stolt, Krister
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Kroner, Corinna
    PTB, Germany.
    Benkova, Miroslava
    CMI Czech Metrology Institute, Czech Republic.
    Pavlas, Jan
    CMI Czech Metrology Institute, Czech Republic.
    Seypka, Veit
    TZW DVGW Technologiezentrum Wasser, Germany.
    Investigations on the influence of total water hardness and ph value on the measurement accuracy of domestic cold water meters2021Inngår i: Water, E-ISSN 2073-4441, Vol. 13, nr 19, artikkel-id 2701Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the framework of the ongoing EMPIR Joint Research Project (JRP) 17IND13 Metrology for real-world domestic water metering (Metrowamet), a main task is to investigate the influence of realistic operation conditions, that is, typical water qualities (suspended particles, degree of hardness, and pH value), on the measurement accuracy. For this purpose, two representative types of cold water meters were investigated in more detail. Initially, the cold water meters were calibrated and then subjected to an accelerated wear test with water of different pH values and degrees of hardness. The accelerated wear tests were designed to reproduce the realistic use and service life of a cold water meter. Subsequently, the cold water meters were re-calibrated to assess the influence of the different water qualities on the measurement accuracy. One of the results was that the measurement accuracy of the water meters investigated was not strongly affected by the water quality. The practical realisation and the measurement results are reported in this paper. © 2021 by the authors.

  • 18.
    Büker, Oliver
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Stolt, Krister
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Lindström, Kent
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Wennergren, Per
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Penttinen, Olle
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Mattiasson, Kerstin
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    A unique test facility for calibration of domestic flow meters under dynamic flow conditions2021Inngår i: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 79, artikkel-id 101934Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the early nineties a hot water test facility was planned and constructed for calibration and testing of volume and flow meters at the National Volume Measurement Laboratory at RISE (formerly SP Technical Research Institute of Sweden). The main feature of the test facility is the capability to measure flow in a wide temperature and flow range with very high accuracy. The objective of the project, which was initiated in 1989, was to design equipment for calibration of flow meters with stable flow and temperature conditions. After many years of international debate whether static testing is adequate to represent the later more dynamic application of domestic water meters, the EMPIR project 17IND13 Metrology for real-world domestic water metering (“Metrowamet”) was launched in 2018. The project investigates the influence of dynamic flow testing on the measurement accuracy of different types of domestic flow meters. One of the main objectives of the project is the development of infrastructure to carry out dynamic flow measurements. The existing test facility at RISE was at the time of construction one of the best hot and cold-water test facilities in the world. Due to the Metrowamet project the test facility has been upgraded to meet the needs of an infrastructure for dynamic flow investigations. The first findings from dynamic consumption profile measurements are reported in this paper. © 2021 The Authors

  • 19.
    Elg, Alf Peter
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Garnacho, F.
    FFII Fundación para el Fomento de la Innovación Industrial, Spain.
    Agazar, M.
    LNE Laboratoire National de Métrologie et d'Essais, France.
    Meisner, J.
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Merev, A.
    TUBITAK Ulusal Metroloji Enstitüsüi, Turkey.
    Houtzager, E.
    VSL BV, Netherlands.
    Hällström, J.
    VTT Oy MIKES, Finland.
    Lahti, K.
    TAU Tampere University, Finland.
    Escurra, C. M.
    TU Delft, Netherlands.
    Platero, C. A.
    Universidad Politécnica de Madrid, Spain.
    Micand, T.
    VETTINER, France.
    Steiner, T.
    HIGHVOLT, Germany.
    Voss, A.
    Haefely AG, Switzerland.
    Research project EMPIR 19ENG02 future energy2020Inngår i: VDE High Voltage Technology 2020, VDE Verlag GmbH , 2020, s. 252-257Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Society's increasing demand for electrical energy, along with the increased integration of remote renewable generation has driven transmission levels to ever higher voltages in order to maintain (or improve) grid efficiency. Consequently, high voltage testing and monitoring beyond voltage levels covered by presently available metrology infrastructures are needed to secure availability and quality of supply. Calibration services for Ultra-High Voltage Direct Current (UHVDC) presently are only available up to 1000 kV. There is a need to extend the DC calibration capabilities for voltage instrument transformers up to 1200 kV and for factory component testing capabilities up to 2000 kV. Also, methods for linear extension of lightning impulse calibration, for dielectric testing of UHV grid equipment, urgently need revision. Recent research has raised questions regarding the validity of the current linearity extension methods for voltages beyond 2500 kV. Furthermore, new methods for calibration are needed for the 0.2 class HVAC voltage instrument transformers for system voltages up to 1200 kV. The current methods used for determination of the voltage dependence are very time consuming, raising the need for methods allowing faster assessment. Finally, with new HVDC transmission grids and associated components, novel methods are needed for detection, classification and localisation of partial discharge (PD) under DC stress. The industry needs methods for reliable monitoring of critical components such as cables, for both HVAC and HVDC, and gas insulated substations (GIS), and techniques for addressing new challenges introduced by HVDC technologies, such as the ability to distinguish PD signals from switching transients in converters and other sources of noise.

  • 20.
    Elg, Alf Peter
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Garnacho, F.
    FFII Fundación para el Fomento de la Innovación Industrial, Spain.
    Agazar, M.
    LNE Laboratoire National de Métrologie et d'Essais, France.
    Meisner, J.
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Merev, A.
    TUBITAK, Turkey.
    Houtzager, E.
    VSL BV, Netherlands.
    Hällström, J.
    VTT, Finland.
    Lahti, K.
    TAU Tampere University Foundation SR, Finland.
    Escurra, C. M.
    TU Delft, Netherlands.
    Platero, C. A.
    Universidad Politécnica de Madrid, Spain.
    Micand, T.
    VETTINER Appareils Vettiner, France.
    Steiner, T.
    HIGHVOLT, Prüftechnik, Germany.
    Voss, A.
    Haefely AG, Switzerland.
    Research project EMPIR 19ENG02 future energy2021Inngår i: VDE High Voltage Technology, VDE Verlag GmbH , 2021, s. 252-257Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Society's increasing demand for electrical energy, along with the increased integration of remote renewable generation has driven transmission levels to ever higher voltages in order to maintain (or improve) grid efficiency. Consequently, high voltage testing and monitoring beyond voltage levels covered by presently available metrology infrastructures are needed to secure availability and quality of supply. Calibration services for Ultra-High Voltage Direct Current (UHVDC) presently are only available up to 1000 kV. There is a need to extend the DC calibration capabilities for voltage instrument transformers up to 1200 kV and for factory component testing capabilities up to 2000 kV. Also, methods for linear extension of lightning impulse calibration, for dielectric testing of UHV grid equipment, urgently need revision. Recent research has raised questions regarding the validity of the current linearity extension methods for voltages beyond 2500 kV. Furthermore, new methods for calibration are needed for the 0.2 class HVAC voltage instrument transformers for system voltages up to 1200 kV. The current methods used for determination of the voltage dependence are very time consuming, raising the need for methods allowing faster assessment. Finally, with new HVDC transmission grids and associated components, novel methods are needed for detection, classification and localisation of partial discharge (PD) under DC stress. The industry needs methods for reliable monitoring of critical components such as cables, for both HVAC and HVDC, and gas insulated substations (GIS), and techniques for addressing new challenges introduced by HVDC technologies, such as the ability to distinguish PD signals from switching transients in converters and other sources of noise.

  • 21.
    Eslamian, Morteza
    et al.
    University of Zanjan, Iran.
    Kharezy, Mohammad
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Thiringer, Torbjörn
    Chalmers University of Technology, Sweden.
    An Accurate Analytical Method for Leakage Inductance Calculation of Shell-type Transformers with Rectangular Windings2021Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 9, s. 72647-72660Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents an accurate analytical method for calculating the leakage inductance of shell-type E-core transformers with rectangular windings. For this purpose, first, an expression for calculating the leakage inductance per unit length inside the core window considering the core walls as the flux-normal boundary condition is derived. Then, a new accurate method for determining the Mean Length of Turns (MLT) based on the total stored energy is presented. The MLT is needed for the leakage inductance calculation using 2-D methods. By dividing the MLT into three partial lengths and calculating the corresponding leakage inductances using three different core window arrangements, the effect of core structure on the total leakage inductance is considered. The method is verified by 3-D FEM simulations as well as the leakage inductance measurements on two different fabricated transformer prototypes. The superiority of the method is also confirmed by comparisons with the previous analytical approaches. The proposed method enables the leakage inductance calculation with an error less than 1%, compared to the 3-D FEM results. Using the presented method, the leakage inductance calculations can be performed rapidly and accurately in the design stage without the need for time-consuming 3-D FEM simulations. CCBYNCND

  • 22.
    Eslamian, Morteza
    et al.
    University of Zanjan, Iran.
    Kharezy, Mohammad
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Thiringer, Torbjörn
    Chalmers University of Technology, Sweden.
    An Accurate Method for Leakage Inductance Calculation of Shell-Type Multi Core-Segment Transformers With Circular Windings2021Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 9, s. 111417-111431Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The leakage field in shell-type transformers is strongly affected by the boundary conditions introduced by the core walls and thus the effect of the core should be considered properly in the leakage inductance calculation. In this paper, a new method for accurate calculation of the leakage inductance of shell-type multi core-segment transformers with circular windings is presented. For this purpose, first, the expressions for self and mutual inductances are derived in cylindrical coordinates considering the core walls as the flux-normal boundary condition. Then, a new approach is proposed for calculating the leakage inductance considering the number and dimensions of the used core segments. The method is developed at first for single and double core-segment transformers (known also as E-core and U-core transformers) and then adopted for shell-type segmented-core transformers. The method is verified by 3-D FEM simulations. The comparisons with the previous analytical methods demonstrate the superiority of the proposed method. A transformer prototype has been built and verification tests have been conducted. The comparisons show that the leakage inductance can be estimated with an error less than 1%, demonstrating a very high accuracy with the proposed method.

  • 23.
    Eslamian, Morteza
    et al.
    University of Zanjan, Iran.
    Kharezy, Mohammad
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Mätteknik.
    Thiringer, Torbjörn
    Chalmers University of Technology, Sweden.
    Calculation of the leakage inductance of medium frequency transformershaving rectangular-shaped windings using an accurate analytical method2019Inngår i: 2019 21st European Conference on Power Electronics and Applications (EPE '19 ECCE Europe), 2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    To achieve the lowest loss by the Zero-Voltage Switching of a Dual Active Bridge converter, it is crucial to precisely calculate the embedded Leakage Inductance of the used Medium Frequency Transformer (MFT). An effective analytical method is proposed for calculation of the leakage inductance of the MFT with rectangular-shaped windings

  • 24.
    Farjana, Sadia
    et al.
    Chalmers University of Technology, Sweden.
    Ghaderi, Mohammadamir
    Chalmers University of Technology, Sweden.
    Zaman, Ashraf
    Chalmers University of Technology, Sweden.
    Rahiminejad, Sofia
    Nasa Jet Propulsion Laboratory,.
    Eriksson, Thomas
    Chalmers University of Technology, Sweden.
    Hansson, Jonas
    Mercene Labs AB, Sweden.
    Li, Yinggang
    Ericsson AB, Sweden.
    Emanuelsson, Thomas
    Gapwaves AB, Sweden.
    Haasl, Sjoerd
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Lundgren, Per
    Chalmers University of Technology, Sweden.
    Enoksson, Peter
    Chalmers University of Technology, Sweden.
    Realizing a 140 GHz Gap Waveguide–Based Array Antenna by Low-Cost Injection Molding and Micromachining2021Inngår i: Journal of Infrared, Millimeter and Terahertz Waves, ISSN 1866-6892, E-ISSN 1866-6906, Vol. 42, nr 8, s. 893-914Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a novel micromachining process to fabricate a 140 GHz planar antenna based on gap waveguide technology to be used in the next-generation backhauling links. The 140 GHz planar array antenna consists of three layers, all of which have been fabricated using polymer-based microfabrication and injection molding. The 140 GHz antenna has the potential to be used as an element in a bigger 3D array in a line-of-sight (LOS) multiple input multiple output (MIMO) configuration to boost the network capacity. In this work, we focus on the fabrication of a single antenna array element based on gap waveguide technology. Depending on the complexity of each antenna layer’s design, three different micromachining techniques, SU8 fabrication, polydimethylsiloxane (PDMS) molding, and injection molding of the polymer (OSTEMER), together with gold (Au) coating, have been utilized to fabricate a single 140 GHz planar array antenna. The input reflection coefficient was measured to be below − 11 dB over a 14% bandwidth from 132 to 152 GHz, and the antenna gain was measured to be 31 dBi at 140 GHz, both of which are in good agreement with the simulations. © 2021, The Author(s).

  • 25.
    Flores-Alsina, Xavier
    et al.
    DTU Technical University of Denmark, Denmark.
    Arnell, Magnus
    RISE Research Institutes of Sweden, Samhällsbyggnad, Infrastruktur och betongbyggande. Lund University, Sweden.
    Corominas, Lluis
    ICRA Catalan Institute for Water Research, Spain.
    Sweetapple, Chris
    University of Exeter, UK.
    Fu, Guangtao
    University of Exeter, UK.
    Butler, David
    University of Exeter, UK.
    Vanrolleghem, P. A.
    Université Laval, Canada.
    Gernaey, Krist V
    DTU Technical University of Denmark, Denmark.
    Jeppsson, Ulf
    Lund Universtity, Sweden.
    Benchmarking strategies to control GHG production and emissions: Chapter 92022Inngår i: Quantification and Modelling of Fugitive Greenhouse Gas Emissions from Urban Water Systems: A report from the IWA Task Group on GHG, IWA Publishing , 2022, s. 213-228Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Benchmarking has been a useful tool for unbiased comparison of control strategies in wastewater treatment plants (WWTPs) in terms of effluent quality, operational cost and risk of suffering microbiology-related total suspended solids (TSS) separation problems. This chapter presents the status of extending the original Benchmark Simulation Model No 2 (BSM2) towards including greenhouse gas (GHG) emissions. A mathematical approach based on a set of comprehensive models that estimate all potential on-site and off-site sources of COinf2/inf, CHinf4/inf and Ninf2/infO is presented and discussed in detail. Based upon the assumptions built into the model structures, simulation results highlight the potential undesirable effects on increased GHG emissions when carrying out local energy optimization in the activated sludge section and/or energy recovery in the anaerobic digester. Although off-site COinf2/inf emissions may decrease in such scenarios due to either lower aeration energy requirement or higher heat and electricity production, these effects may be counterbalanced by increased Ninf2/infO emissions, especially since Ninf2/infO has a 300-fold stronger greenhouse effect than COinf2/inf. The reported results emphasize the importance of using integrated approaches when comparing and evaluating (plant-wide) control strategies in WWTPs for more informed operational decision-making. 

  • 26.
    Forssén, C
    et al.
    RISE Research Institutes of Sweden. Umeå University, Sweden.
    Silander, I
    Umeå University, Sweden.
    Zakrisson, Johan
    Umeå University, Sweden.
    Zelan, Martin
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Axner, O
    Umeå University, Sweden.
    An optical pascal in Sweden2022Inngår i: Journal of Optics, ISSN 2040-8978, E-ISSN 2040-8986, Vol. 24, nr 3, artikkel-id 033002Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    By measuring the refractivity and the temperature of a gas, its pressure can be assessed from fundamental principles. The highest performing instruments are based on Fabry-Perot cavities where a laser is used to probe the frequency of a cavity mode, which is shifted in relation to the refractivity of the gas in the cavity. Recent activities have indicated that such systems can demonstrate an extended uncertainty in the 10 ppm (parts-per-million or 10-6) range. As a means to reduce the influence of various types of disturbances (primarily drifts and fluctuations) a methodology based on modulation, denoted gas modulation refractometry (GAMOR), has recently been developed. Systems based on this methodology are in general high-performance, e.g. they have demonstrated precision in the sub-ppm range, and they are sturdy. They can also be made autonomous, allowing for automated and unattended operation for virtually infinite periods of time. To a large degree, the development of such instruments depends on the access to modern photonic components, e.g. narrow line-width lasers, electro-and acousto-optic components, and various types of fiber components. This work highlights the role of such modern devices in GAMOR-based instrumentation and provides a review on the recent development of such instruments in Sweden that has been carried out in a close collaboration between a research institute and the Academy. It is shown that the use of state-of-the-art photonic devices allows sturdy, automated and miniaturized instrumentation that, for the benefit of industry, can serve as standards for pressure and provide fast, unattended, and calibration-free pressure assessments at a fraction of the present cost. © 2022 The Author(s).

  • 27.
    Forssén, Clayton
    et al.
    RISE Research Institutes of Sweden. Umeå University, Sweden.
    Silander, Isak
    Umeå University, Sweden.
    Zakrisson, Johan
    Umeå University, Sweden.
    Axner, Ove
    Umeå University, Sweden.
    Zelan, Martin
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    The short-term performances of two independent gas modulated refractometers for pressure assessments2021Inngår i: Sensors, E-ISSN 1424-8220, Vol. 21, nr 18, artikkel-id 6272Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Refractometry is a powerful technique for pressure assessments that, due to the recent redefinition of the SI system, also offers a new route to realizing the SI unit of pressure, the Pascal. Gas modulation refractometry (GAMOR) is a methodology that has demonstrated an outstanding ability to mitigate the influences of drifts and fluctuations, leading to long-term precision in the 10−7 region. However, its short-term performance, which is of importance for a variety of applications, has not yet been scrutinized. To assess this, we investigated the short-term performance (in terms of precision) of two similar, but independent, dual Fabry–Perot cavity refractometers utilizing the GAMOR methodology. Both systems assessed the same pressure produced by a dead weight piston gauge. That way, their short-term responses were assessed without being compromised by any pressure fluctuations produced by the piston gauge or the gas delivery system. We found that the two refractometer systems have a significantly higher degree of concordance (in the 10−8 range at 1 s) than what either of them has with the piston gauge. This shows that the refractometry systems under scrutiny are capable of assessing rapidly varying pressures (with bandwidths up to 2 Hz) with precision in the 10−8 range. © 2021 by the authors.

  • 28.
    Furborg, Joe
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik.
    Söderberg, Andreas
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik.
    Introduction to Hardware Architecture and Evaluation According to EN ISO 13849-12019Rapport (Annet vitenskapelig)
    Abstract [en]

    Hardware realization of safety functions, in safety related machinery control systems can, according to EN ISO 13849-1, be realized as one out of five distinct designated architectures. This report gives examples and guidance for choosing a designated architecture which fulfills the required risk reductive measure of the safety function.

    Fulltekst (pdf)
    fulltext
  • 29.
    Galkin, Nikolai
    et al.
    Luleå University, Sweden.
    Yang, Chen-Wei
    Luleå University, Sweden.
    Berezovskaya, Yulia
    Luleå University, Sweden.
    Vesterlund, Mattias
    RISE Research Institutes of Sweden, Digitala system, Datavetenskap.
    Vyatkin, Valeriy
    Luleå University, Sweden.
    On Modelling of Edge Datacentre Microgrid for Participation in Smart Energy Infrastructures2022Inngår i: IEEE Open Journal of the Industrial Electronics Society, ISSN 2644-1284, Vol. 3, s. 50-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Datacentres are becoming a sizable part of the energy system and are one of the biggest consumers of the energy grid. The so-called “Green Datacentre” is capable of not only consuming but also producing power, thus becoming an important kind of prosumers in the electric grid. Green datacentres consist of a microgrid with a backup uninterrupted power supply and renewable generation, e.g., using photovoltaic panels. As such, datacentres could realistically be important participants in demand/response applications. However, this requires reconsidering their currently rigid control and automation systems and the use of simulation models for online estimation of the control actions impact. This paper presents such a microgrid simulation model modelled after a real edge datacentre. A case study consumption scenario is presented for the purpose of validating the developed microgrid model against data traces collected from the green edge datacentre. Both simulation and real-time validation tests are performed to validate the accuracy of the datacentre model. Then the model is connected to the automation environment to be used for the online impact estimation and virtual commissioning purposes.

  • 30.
    Geréb, Gabor
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Johannisson, Pontus
    RISE Research Institutes of Sweden.
    Landén, Lars
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Sensor Platform for Low-Power Underwater Monitoring using Hydroacoustic Communication2021Inngår i: 2021 Smart Systems Integration (SSI), 2021Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The development of a compact, battery-powered sensor platform intended for underwater applications and using hydroacoustic communication is reported. The design and manufacturing of the device is described with emphasis on the method used to monitor and reduce the current consumption. The devices have been encapsulated in epoxy and evaluated under field conditions, which showed that the system is usable in its current form. In addition to hardware improvements, e.g., in order to increase battery lifetime, the next generation of the system will implement forward error correction and improved receiver signal processing to reduce the impact of signal reflections.

  • 31.
    Grönqvist, Hans
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Tegehall, Per-Erik
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Lidström, Oscar
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Wünscher, Heike
    CiS Forschungsinstitut für Mikrosensorik GmbH, Germany.
    Steinke, Arndt
    CiS Forschungsinstitut für Mikrosensorik GmbH, Germany.
    Richert, Hans
    SETEK Elektronik AB, Sweden.
    Lagerkvist, Peter
    Niranova AB, Sweden.
    Unit for Investigation of the Working Environment for electronic units in harsh environment2017Inngår i: Advanced Microsystems for Automotive Applications 2017: Smart Systems Transforming the Automobile / [ed] Zachäus, C., Müller, B., Meyer, G., Springer, 2017, s. 13-22Konferansepaper (Fagfellevurdert)
    Abstract [en]

    When electronic equipment is used in harsh environments with long expected lifetimethere is a need to understand that environment more in detail. This situationis today a reality for many application areas including the automotive sector,heavy industry, the defense sector and more.To fully understand the working environment a unit has been developed to monitorphysical data such as temperature, vibration, humidity, condensation etc. to beused in the product development phase for new products.The paper presents the underlying principles for the ESU (Environmental SupervisionUnit) and details on the design.

  • 32. Haldoupis, C.
    et al.
    Amvrosiadi, Nino
    University of Crete, Greece.
    Cotts, B. R. T.
    van der Velde, O. A.
    Chanrion, O.
    Neubert, T.
    More evidence for a one-to-one correlation between Sprites and Early VLF perturbations2010Inngår i: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 115, nr A7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Past studies have shown a correlation between sprites and early VLF perturbations, but the reported correlation varies widely from ?50% to 100%. The present study resolves these large discrepancies by analyzing several case studies of sprite and narrowband VLF observations, in which multiple transmitter-receiver VLF pairs with great circle paths (GCPs) passing near a sprite-producing thunderstorm were available. In this setup, the multiple paths act in a complementary way that makes the detection of early VLF perturbations much more probable compared to a single VLF path that can miss several of them, a fact that was overlooked in past studies. The evidence shows that visible sprite occurrences are accompanied by early VLF perturbations in a one-to-one correspondence. This implies that the sprite generation mechanism may cause also sub-ionospheric conductivity disturbances that produce early VLF events. However, the one-to-one visible sprite to early VLF event correspondence, if viewed conversely, appears not to be always reciprocal. This is because the number of early events detected in some case studies was considerably larger than the number of visible sprites. Since the great majority of the early events not accompanied by visible sprites appeared to be caused by positive cloud to ground (+CG) lightning discharges, it is possible that sprites or sprite halos were concurrently present in these events as well but were missed by the sprite-watch camera detection system. In order for this option to be resolved we need more studies using highly sensitive optical systems capable of detecting weaker sprites, sprite halos and elves.

  • 33.
    He, Hans
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Chalmers University of Technology, Sweden.
    Shetty, Naveen
    Chalmers University of Technology, Sweden.
    Kubatkin, Sergey
    Chalmers University of Technology, Sweden.
    Stadler, Pascal
    Chalmers University of Technology, Sweden.
    Löfwander, Tomas
    Chalmers University of Technology, Sweden.
    Fogelström, Mikael
    Chalmers University of Technology, Sweden.
    Miranda-Valenzuela, JC
    Tecnologico de Monterrey, Mexico.
    Yakimova, Rositsa
    Linköping University, Sweden; Graphensic AB, Sweden.
    Bauch, Thilo
    Chalmers University of Technology, Sweden.
    Lara-Avila, Samuel
    Chalmers University of Technology, Sweden.
    Highly efficient UV detection in a metal-semiconductor-metal detector with epigraphene2022Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 120, nr 19, artikkel-id 191101Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We show that epitaxial graphene on silicon carbide (epigraphene) grown at high temperatures (T >1850 °C) readily acts as material for implementing solar-blind ultraviolet (UV) detectors with outstanding performance. We present centimeter-sized epigraphene metal-semiconductor-metal (MSM) detectors with a peak external quantum efficiency of η ∼85% for wavelengths λ = 250-280 nm, corresponding to nearly 100% internal quantum efficiency when accounting for reflection losses. Zero bias operation is possible in asymmetric devices, with the responsivity to UV remaining as high as R = 134 mA/W, making this a self-powered detector. The low dark currents Io ∼50 fA translate into an estimated record high specific detectivity D = 3.5 × 1015 Jones. The performance that we demonstrate, together with material reproducibility, renders epigraphene technologically attractive to implement high-performance planar MSM devices with a low processing effort, including multi-pixel UV sensor arrays, suitable for a number of practical applications. © 2022 Author(s).

  • 34.
    Henriksson, Andreas
    et al.
    Chalmers University of Technology, Sweden.
    Simonsson, John
    Volvo Cars AB, Sweden.
    Lundgren, Urban
    RISE Research Institutes of Sweden, Säkerhet och transport, Fordon och automatisering.
    Ankarson, Peter
    RISE Research Institutes of Sweden, Säkerhet och transport, Fordon och automatisering.
    Cable Modeling for Accurate Estimation of Currentand Voltage Ripple in Electric Vehicles2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An electric vehicle is a complex system where multipleconverters are connected to a common DC-bus. In order todetermine the current and voltage harmonics on the DC-bus, allingoing components and subsystems needs to be modeled on adetailed level. In this paper, the focus lies on cable modelingwhere a high frequency cable model is incorporated in a drivesystem model. The resulting current and voltage ripple in thesystem is then compared to measurements in an experimentalsetup. Due to the improved cable model and an extensive systemparameter identification procedure, the usage of the systemmodel was found valid for harmonic frequencies up to 1 MHz.The main harmonic component at 20 kHz was simulated with~1.7 % accuracy and the components in the range 35 kHz to200 kHz with <6 % accuracy compared to measurements.

  • 35.
    Hillberg, Emil
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Flexibility means for power grid Resilience2021Inngår i: ISGT Europe 2021. Panel session: Electrification and digitalization pathway onland, at sea & in the air. 21st October 2021: ISGT Europe 2021, 2021Konferansepaper (Annet vitenskapelig)
    Fulltekst (pdf)
    fulltext
  • 36.
    Hillberg, Emil
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Lundberg, Martin
    Lund University, Sweden.
    Samuelsson, Olof
    Lund University, Sweden.
    Alternative network development – need for flexible solutions for operation and planning of distribution and transmission grids2020Inngår i: Proc of Colloquium - Toronto 2020, 2020, s. 281-Konferansepaper (Fagfellevurdert)
  • 37.
    Hillberg, Emil
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Oleinikova, Irina
    NTNU, Norway.
    micro vs MEGA grid solutions for the future power system2021Inngår i: : Proc of CIGRE Centennial Session, 2021, 2021, s. C1-303-Konferansepaper (Fagfellevurdert)
  • 38.
    Hoffmann, Lars
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Immersion of 400 volt traction battery in fresh water and salt water2018Rapport (Annet vitenskapelig)
    Abstract [en]

    By means of these tests, where Li-ion batteries have been immersed in both fresh water as well as 3 % salt water, it was demonstrated that it is completely safe to be both in the water and in the direct proximity of a battery, in this case, with 400 volt direct current. This conclusion holds, on the condition that the exposed individual, in the direct proximity of the battery, does not actively touch any of the battery's poles. Analogous to this, it can be assumed that nor does an electric vehicle, which for some reason has entered a watercourse consisting of either fresh water or seawater, constitute a danger for those bathing in the immediate vicinity of the electric vehicle. However, this assumes that an individual who is diving or bathing does not touch exposed parts of the traction system (explanation, e.g. open battery case and directly taking hold of live exposed parts of the traction battery and its cells). However, these parts are normally built into the vehicle's protective structures and are hard to access by inadvertent contact. The commercially available, factory produced, electric vehicles made by serious designers and automotive companies have a monitoring system in their systems that immediately switch off the power supply from the traction battery to the electric vehicle's traction system. This provides additional personal protection for anyone (e.g. fireman) who has the task of helping passengers who have entered a watercourse along with their electric vehicle. During immersion in salt water, a pungent chlorine gas was generated, which can be thought to collect inside a vehicle's air pockets; whether these gas mixtures are flammable or not has not been studied during these tests. No drastic events could be observed during any of these tests, however, one should be aware that a battery, which for some reason has been in immersed in water and has not discharged, can still have a hazardous voltage level after many months. This is something that the rescue service, automotive mechanics and car recyclers in particular should be informed.

    Fulltekst (pdf)
    fulltext
  • 39.
    Jayasankar, Divya
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Drakinskiy, V.
    Chalmers University of Technology, Sweden.
    Myremark, M.
    Chalmers University of Technology, Sweden.
    Sobis, P.
    Omnisys Instruments, Sweden.
    Stake, J.
    Chalmers University of Technology, Sweden.
    Design and development of 3.5 THz Schottky-based fundamental mixer2021Inngår i: 2020 50th European Microwave Conference, EuMC 2020, Institute of Electrical and Electronics Engineers Inc. , 2021, s. 595-598Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Broadband Schottky diode mixers operating at room-temperature are crucial for terahertz heterodyne instrumentation in space-borne applications. In this paper, we present the design of a compact 3.5 THz fundamental single-ended Schottky diode mixer. The design is based on Schottky diodes with a sub-micron anode area, defined using nanolithography techniques, and integrated with suspended strip lines on an ultra-thin GaAs-membrane. 

  • 40.
    Jayasankar, Divya
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Chalmers University of Technology, Sweden; Omnisys Instruments AB, Sweden.
    Drakinskiy, Vladimir
    RISE Research Institutes of Sweden. Chalmers University of Technology, Sweden; Omnisys Instruments AB, Sweden.
    Rothbart, Nick
    Institute of Optical Sensor Systems, Germany; Humboldt-Universitat zu Berlin, Germany.
    Richter, Heiko
    Institute of Optical Sensor Systems, Germany; Humboldt-Universitat zu Berlin, Germany.
    Lu, Xiang
    Leibniz-Institut im Forschungsverbund Berlin E. V., Germany.
    Schrottke, Lutz
    Leibniz-Institut im Forschungsverbund Berlin E. V., Germany.
    Grahn, Holger
    Leibniz-Institut im Forschungsverbund Berlin E. V., Germany.
    Wienold, Martin
    Institute of Optical Sensor Systems, Germany; Humboldt-Universitat zu Berlin, Germany.
    Hubers, HW
    Institute of Optical Sensor Systems, Germany; Humboldt-Universitat zu Berlin, Germany.
    Sobis, Peter
    RISE Research Institutes of Sweden. Chalmers University of Technology, Sweden; Omnisys Instruments AB, Sweden.
    Stake, Jan
    RISE Research Institutes of Sweden. Chalmers University of Technology, Sweden; Omnisys Instruments AB, Sweden.
    A 3.5-THz, ×6-Harmonic, Single-Ended Schottky Diode Mixer for Frequency Stabilization of Quantum-Cascade Lasers2021Inngår i: IEEE Transactions on Terahertz Science and Technology, ISSN 2156-342X, E-ISSN 2156-3446, Vol. 11, nr 6, s. 684-694Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Efficient and compact frequency converters are essential for frequency stabilization of terahertz sources. In this article, we present a 3.5-THz, × 6-harmonic, integrated Schottky diode mixer operating at room temperature. The designed frequency converter is based on a single-ended, planar Schottky diode with a submicron anode contact area defined on a suspended 2-μ m ultra-thin gallium arsenide substrate. The dc-grounded anode pad was combined with the radio frequency E-plane probe, which resulted in an electrically compact circuit. At 200-MHz intermediate frequency, a mixer conversion loss of about 59 dB is measured resulting in a 40-dB signal-to-noise ratio for phase locking a 3.5-THz quantum-cascade laser. Using a quasi-static diode model combined with electromagnetic simulations, good agreement with the measured results was obtained. Harmonic frequency converters without the need of cryogenic cooling will help in the realization of highly sensitive space and air-borne heterodyne receivers. 

  • 41.
    Johannesson, Pär
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Tillämpad mekanik.
    Lang, X.
    Chalmers University of Technology, Sweden.
    Yang, S. -H
    Chalmers University of Technology, Sweden.
    Johnson, Erland
    RISE Research Institutes of Sweden, Material och produktion, Tillämpad mekanik.
    Ringsberg, J. W.
    Chalmers University of Technology, Sweden.
    Mechanical reliability of flexible power cables for marine energy2021Inngår i: Proceedings of the European Wave and Tidal Energy ConferencePages 2146-1 - 2146-102021, European Wave and Tidal Energy Conference Series , 2021, s. 2146-1-2146-10Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Marine power cables play a crucial role to utilize energy in marine areas, such as offshore wind, wave energy and tidal energy. Marine energy devices are typically grouped into arrays to increase the economic viability, and power cables transfer the energy from the devices to a central hub which is then transmitted ashore. Cables connected to moving devices may experience millions of load cycles per year, and thus they need to be flexible and designed for mechanical loads due to the movements of the cable. In this study, the focus is on the mechanical life of flexible cables connecting devices to hubs, and thus lowand medium voltage power cables is the focus. The reliability design method Variational Mode and Effect Analysis (VMEA) is applied that is based on identifying and quantifying different types of uncertainty sources, such as scatter, model uncertainties and statistical uncertainties. It implements a load-strength-approach that combines numerical simulations to assess the loads on the cable and experimental tests to assess the strength of the cable. The VMEA method is demonstrated for an evaluation of bending fatigue, and it has been found to be a useful tool to evaluate uncertainties in fatigue life for cables in WEC (Wave Energy Converter) systems during the design phase. The results give a firm foundation for evaluation of safety against fatigue and are also helpful for identifying weak spots in the reliability assessment that can motivate actions  in the improvement process. Uncertainties in terms of scatter, statistical uncertainty and model uncertainty have been evaluated with respect to the WaveEL 3.0, a WEC designed by the company Waves4Power, and deployed in Runde, Norway. A major contribution to the overall uncertainty is found to originate from the fatigue life model, both in terms of scatter and model uncertainty. 

  • 42.
    Johannesson, Pär
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik.
    Lang, Xiao
    Chalmers University of Technology, Sweden.
    Johnson, Erland
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik. Chalmers University of Technology, Sweden.
    Ringsberg, Jonas W
    Chalmers University of Technology, Sweden.
    Mechanical Reliability Analysis of Flexible Power Cables for Marine Energy2022Inngår i: Journal of Marine Science and Engineering, E-ISSN 2077-1312, Vol. 10, nr 6, artikkel-id 716Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Marine power cables connected to moving devices at sea may experience millions of load cycles per year, and thus they need to be flexible due to the movements of the cable and designed for mechanical loads. In this study, the focus is on the mechanical life of flexible low-and medium voltage power cables connecting devices to hubs. The reliability design method Variational Mode and Effect Analysis (VMEA) is applied, based on identifying and quantifying different types of uncertainty sources, including scatter, model and statistical uncertainties. It implements a load–strength approach that combines numerical simulations to assess the loads on the cable and experimental tests to assess the strength of the cable. The VMEA method is demonstrated for an evaluation of bending fatigue, and is found to be a useful tool to evaluate uncertainties in fatigue life for WEC (Wave Energy Converter) system cables during the design phase. The results give a firm foundation for the evaluation of safety against fatigue and are also helpful for identifying weak spots in the reliability assessment, thereby motivating actions in the improvement process. Uncertainties in terms of scatter, statistical uncertainty and model uncertainty are evaluated with respect to the WaveEL 3.0, a WEC designed by the company Waves4Power, and deployed in Runde, Norway. A major contribution to the overall uncertainty is found to originate from the fatigue life model, both in terms of scatter and model uncertainty. © 2022 by the authors. 

  • 43.
    Kahkonen, Henri
    et al.
    Aalto University, Finland.
    Proper, Sebastian
    RISE Research Institutes of Sweden, Material och produktion, Tillverkningsprocesser.
    Ala-Laurinaho, Juha
    Aalto University, Finland.
    Viikari, Ville
    Aalto University, Finland.
    Comparison of additively manufactured and machined antenna array performance at Ka band2022Inngår i: IEEE Antennas and Wireless Propagation Letters, ISSN 1536-1225, E-ISSN 1548-5757, Vol. 21, nr 1, s. 9-13Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Additive manufacturing (AM) is a rapidly developing field which potentially decreases the manufacturing costs and enables increasingly complex antenna shapes. Metal-based AM might be particularly useful to manufacture antennas at mm-wave range, because there antennas are physically small enough making additive manufacturing cost efficient, and manufacturing accuracy could still suffice for good electrical performance. In this paper, two additively manufactured and an identical machined fully metallic Ka-band Vivaldi antenna arrays are compared. The manufactured antenna arrays are compared using RF-measurements to conclude the feasibility of AM for manufacturing antenna arrays at mm-wave frequencies. Comparison of the measured radiation patterns and realized gains of each of the antenna arrays between 26 and 40 GHz shows close to identical radiation patterns for all the arrays. A loss in efficiency of 0.51.5 dB is observed in the AM arrays when compared to the machined array due to the used materials and the surface roughness. 

  • 44.
    Karlsson, Kristian
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Elektronik.
    Toss, Henrik
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Elektronik.
    Lang, John
    Autoliv, Sweden.
    Costagliola, Francesco
    Volvo Car Corporation, Sweden.
    Zheng, Tian
    Volvo Car Corporation, Sweden.
    Marel, Elias
    Volvo Car Corporation, Sweden.
    HiFi Radar Target: High fidelity soft targets and radar simulation for more efficient testing (real and virtual)2018Rapport (Annet vitenskapelig)
    Abstract [en]

    The 77 GHz radar is a crucial sensor in the Advanced Driver Assistance System (ADAS) and Autonomous Driving (AD) system due to its ability to detect and track objects at distances up to 200 meters. To ensure high reliability of the radar function, extensive testing with soft surrogate targets is needed. However, the radar response of a surrogate target may differ from that of real targets, causing unexpected reactions of the ADAS and AD functions in real traffic situations. The first project goal was therefore to develop and validate realistic soft surrogate targets, a work which was performed in several steps. First radar reference targets were designed and verified. Secondly procedures for calibration of automotive radars were developed. Finally, a thorough investigation on Radar Cross Section (RCS) characterization methods for large test objects on the test track was conducted resulting in several measurement setups and measurement procedures including uncertainty analysis. Now, with the ability to perform repeatable and reliable RCS characterizations, several real and surrogate targets were characterized and work on improving RCS profile of surrogate targets were conducted.Strong competition in the automotive industry and the need to validate more and more complex functions (including autonomous drive) drives the development of virtual test methods. The ability to test the ADAS or AD functions virtually early in the development will save considerable time and cost. However, there were no such tools available with full radar simulation in-loop available prior to the project, which was the reason for the second goal of this project: an ADAS/AD system simulation tool-chain with radar simulation in-loop.The HiFi Radar Target project (diarienr. 2015-04852) was an FFI project within the Electronics, Software and Communications program. After prolongation it was a 30-month project that started 2015-12-31 and ended 2018-06-30. The project had a total budget of 15.9 MSEK.

    Fulltekst (pdf)
    fulltext
  • 45.
    Kawahara, Jun
    et al.
    RISE., Swedish ICT, Acreo. Linköping University, Sweden; Lintec Corporation, Japan.
    Andersson Ersman, Peter
    Wang, Xin
    RISE., Swedish ICT, Acreo.
    Gustafsson, Göran
    RISE., Swedish ICT, Acreo.
    Granberg, Hjalmar
    RISE., Innventia.
    Berggren, Magnus
    Linköping University, Sweden.
    Reconfigurable sticker label electronics manufactured from nanofibrillated cellulose-based self-adhesive organic electronic materials2013Inngår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 14, nr 11, s. 3061-3069Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Low voltage operated electrochemical devices can be produced from electrically conducting polymers and polyelectrolytes. Here, we report how such polymers and polyelectrolytes can be cast together with nanofibrillated cellulose (NFC) derived from wood. The resulting films, which carry ionic or electronic functionalities, are all-organic, disposable, light-weight, flexible, self-adhesive, elastic and self-supporting. The mechanical and self-adhesive properties of the films enable simple and flexible electronic systems by assembling the films into various kinds of components using a "cut and stick" method. Additionally, the self-adhesive surfaces provide a new concept that not only allows for simplified system integration of printed electronic components, but also allows for a unique possibility to detach and reconfigure one or several subcomponents by a "peel and stick" method to create yet another device configuration. This is demonstrated by a stack of two films that first served as the electrolyte layer and the pixel electrode of an electrochromic display, which then was detached from each other and transferred to another configuration, thus becoming the electrolyte and gate electrode of an electrochemical transistor. Further, smart pixels, consisting of the combination of one electrochromic pixel and one electrochemical transistor, have successfully been manufactured with the NFC-hybridized materials. The concept of system reconfiguration was further explored by that a pixel electrode charged to its colored state could be detached and then integrated on top of a transistor channel. This resulted in spontaneous discharging and associated current modulation of the transistor channel without applying any additional gate voltage. Our peel and stick approach promises for novel reconfigurable electronic devices, e.g. in sensor, label and security applications.

  • 46.
    Kharezy, Mohammad
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Chalmers University of Technology, Sweden.
    Mirzaei, Hassan
    University of Zanjan, Iran.
    Thiringer, Torbjörn
    Chalmers University of Technology, Sweden.
    Serdyuk, Yuriy
    Chalmers University of Technology, Sweden.
    Green Solution for Insulation System of a Medium Frequency High Voltage Transformer for an Offshore Wind Farm2022Inngår i: Energies, E-ISSN 1996-1073, Vol. 15, nr 6, artikkel-id 1998Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High Voltage Direct Current (HVDC) transmission represents the most efficient way for transporting produced electrical energy from remotely located offshore wind farms to the shore. Such systems are implemented today using very expensive and large power transformers and converter stations placed on dedicated platforms. The present study aims at elaborating a compact solution for an energy collections system. The solution allows for a minimum of total transformer weight in the wind turbine nacelle reducing or even eliminating the need for a sea-based platform(s). The heart of the project is a Medium Frequency Transformer (MFT) that has a high DC voltage insulation towards ground. The transformer is employed in a DC/DC converter that delivers the energy into a serial array without additional conversion units. The insulation design methodology of an environmentally friendly HV insulation system for an MFT, based on pressboard and biodegradable oil, is introduced. The measurement method and results of the measurements of electrical conductivities of the transformer oil and Oil Impregnated Pressboard (OIP) are reported. The measurements show that the biodegradable ester oil/OIP conductivities are generally higher than the mineral oil/OIP conductivities. Numerical simulations reveal that the performance of the insulation system is slightly better when ester oil is used. Additionally, a lower temperature dependency for ester oil/OIP conductivities is observed, with the result that the transformer filled with ester oil is less sensitive to temperature variations. © 2022 by the authors.

  • 47.
    Kharezy, Mohammad
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Morteza, Eslamian
    University of Zanjan, Iran.
    Thiringer, Torbjörn
    Chalmers University of Technology, Sweden.
    Insulation Design of a Medium Frequency Power Transformer for a Cost-Effective Series High Voltage DC Collection Network of an Offshore Wind Farm2019Inngår i: Proceedings of the 21st International Symposium on High Voltage Engineering, Switzerland: Springer Publishing Company, 2019, s. 06-1417Konferansepaper (Fagfellevurdert)
    Abstract [en]

    DC can be used advantageously in transmission of power from offshore wind farms, utilizing series connection of the individual turbines’ outputs. Employing individual wind turbine converters, operating at high frequency, the advantage of DC can be achieved without the need for a large central converter. This solution obviates the need of expensive, bulky and heavy 50 Hz transformer or centralized DC/DC converter platforms.

    Power electronic converters are among the enabling technologies to establish a series DC intertie system. The most important advantage of a DC/DC converter using a Medium Frequency Power Transformer (MFPT) is its compact size in comparison with a normal grid frequency transformer.

    The function of a MFPT is to provide voltage step up and isolation between generators and the HVDC link. The need for a compact structure dictates further design constraints. A MFPT should have a high-power transmission capability from a small volume as well as minimal internal insolation distances. Furthermore, in the series DC integration circuit, DC/DC converters can experience a very high offset DC voltage depending on the converter’s position with respect to earth (in the range of one or two hundred kilovolts), while the primary side (wind turbine generator side) is only exposed to a few kV.

    Due to its promising features, many research activities have been devoted to the design and optimization of MFPTs. However, only a few activities specifically addressed the insulation requirements for them.

  • 48.
    Kroner, Corinna
    et al.
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Akselli, Basak
    Tubitak Ume, Turkey.
    Benková, Miroslava
    Czech Metrology Institute, Czech Republic.
    Borchling, Alexander
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Büker, Oliver
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Christoffersen, Nikki
    FORCE Technology, Denmark.
    Pavlas, Jan
    Czech Metrology Institute, Czech Republic.
    Schumann, Daniel
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Seypka, Veit
    DVGW-Technologiezentrum Wasser, Germany.
    Ünsal, Bulent
    Tubitak Ume, Turkey.
    Warnecke, Heiko
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Evaluation of the measurement performance of water meters depending on water quality2022Inngår i: Water Science and Technology: Water Supply, ISSN 1606-9749, E-ISSN 1607-0798, Vol. 22, nr 4, s. 4700-4715Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Water meters of different types and sizes are used to monitor and bill the water supply. Although the water is of drinking water quality, its chemo-physical properties often adversely affect the measuring behaviour of a meter after a while. There is thus the risk that they no longer meet legal requirements and may no longer be used. In this paper a test regime with a focus on pH, total hardness and particle load is presented which allows water meters to be tested closer to their operating conditions prior to placing them on the market. The regime goes beyond the conventional continuous durability test as described in OIML R49:2013(E) and ISO 4064:2014. The feasibility and reliability of the test regime has been demonstrated through implementation at different facilities. In the study, the measurement performance of water meters of various types and from different manufacturers was also investigated. A heterogeneous spread of measurement errors was found for both, water meters in mint conditions and those which were exposed to a defined water quality. Furthermore, compared to the conventional continuous durability test, the test regime developed in the study generally leads to stronger changes in the measurement error of the water meters. © 2022 The Authors

  • 49.
    Kroner, Desiree
    et al.
    Dalarna university, Sweden, Luleå university of technology, Sweden.
    Lundgren, Urban
    RISE Research Institutes of Sweden, Säkerhet och transport.
    Radiated Electromagnetic Emissions from Photovoltaic Systems - Measurement Results from Inverter and Modules2023Inngår i: IEEE International Symposium on Electromagnetic Compatibility, ISSN 1077-4076, Vol. 2023-SeptemberArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Radiated electromagnetic emissions of photovoltaic systems causing interference with radiocommunication can pose a major barrier to further photovoltaic penetration. This is particularly critical close to sensitive infrastructures such as hospitals, airports, and communication facilities. To understand the impact of each component and installation detail, we performed systematic emission measurements on comparable commercial photovoltaic systems in the range 150 kHz to 30 MHz. Our measurements indicate that systems with module optimizers are the main cause of increased emissions. The choice of a specific module type can increase emissions from inverter systems with module optimizers, while changes in cable management and earthing do not substantially affect emissions. For the module optimizer measurements, emissions were significantly increased when replacing aluminum framed half-cut modules with frameless bifacial glass-glass modules. 

  • 50.
    Li, Shanghua
    et al.
    ABB, Sweden.
    Karlsson, Mattias
    ABB, Sweden.
    Liu, Rongsheng
    ABB, Sweden.
    Ahniyaz, Anwar
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Fornara, Andrea
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Johansson Salazar-Sandoval, Eric
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    The effect of ceria nanoparticles on the breakdown strength of transformer oil2015Inngår i: 2015 IEEE 11th International Conference on the Properties and Applications of Dielectric Materials (ICPADM), Institute of Electrical and Electronics Engineers (IEEE), 2015, s. 289-292Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Nanotechnologies have potential to be used in transformer industry in enhancing material properties which may lead to a compact design of transformer and reduced manufacturing cost. Effect of adding different nanoparticles such as titania, silica, nano-diamond, etc. has been studied in literatures. In this paper, nano-ceria particles have been successfully added into transformer mineral oil with different content. The suspension is very stable and no segmentation can be observed over several months. The ceria nanoparticles are commercially available, which have a quite narrow size distribution. UV-Vis, TGA and FT-IR are used to characterize the ceria nanofluids. The water content of the ceria nanofluids has been measured by Karl Fisher titration, which is important for the breakdown strength of transformer oil. AC voltage breakdown and lightning impulse voltage breakdown measurements have been performed on the ceria nanofluids. An enhancement of 15% on AC breakdown voltage has been observed on ceria nanofluids with some content compared to reference transformer oil. On the other hand, no clear difference on the lightning impulse breakdown voltage is observed between the ceria nanofluids and reference transformer oil.

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