Blar i tittel Artikler, rapporter og annet (elektroteknologi)

Viser treff 59-78 av 118

    • Keeping track of samples in multidisciplinary fieldwork 

      Ellingsen, Pål Gunnar; Ferrighi, Lara; Godøy, Øystein Arne; Gabrielsen, Tove M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-10)
      We here present methods, tools and results for efficiently collecting metadata and tracking samples collected in the field. The samples and metadata were collected during scientific cruises conducted by amongst others marine biologists, oceanographers, geochemists and marine geologists in the Nansen Legacy project. It is here reported on the successful development and implementation of a system ...

    • Load modeling from smart meter data using neural network methods 

      Kianpoor, Nasrin; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2021)
      Electricity load modeling plays a critical role to conduct load forecasting or other applications such as non-intrusive load monitoring. For such a reason, this paper investigates a comparison study of two common artificial neural network methods (Multilayer perceptron (MLP) and radial basis function neural network (RBF-NN) for home load modeling application. The accuracy of load modeling using ...

    • Maximum Available Power of Undersea Capacitive Coupling in a Wireless Power Transfer System 

      Al-Sallami, Hussein; Hoff, Bjarte; Østrem, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-23)
      This paper studies the maximum available power of a dissipative capacitive power transfer (CPT) system submerged in seawater. The CPT system's maximum power capability is driven using the network theory, precisely the conjugate-image approach. The equations of the maximum available load power and the system's corresponding efficiency are expressed as a function of the capacitive coupling parameters. ...

    • Mode division multiplexing free space optics system with 3D hybrid modulation under dust and fog 

      Pottoo, Sahil Nazir (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-13)
      Mode division multiplexing (MDM) is an emerging information transmission technique in which multiple data signals can be transmitted simultaneously on different modes of a single wavelength laser beam over a free-space channel. MDM is a potential technique for the realization of high-speed spectral efficient communication links for future generations of wireless networks. We present a novel MDM-based ...

    • Modeling and Attitude Control of Satellites in Elliptical Orbits 

      Oland, Espen (Peer reviewed; Chapter, 2018-11-05)
      The attitude determination and control system (ADCS) for spacecraft is responsible for determining its orientation using sensor measurements and then applying actuation forces to change the orientation. This chapter details the different components required for a complete attitude determination and control system for satellites moving in elliptical orbits. Specifically, the chapter details the orbital ...

    • Modelling and simulation of interaction forces in tugboat-assisted docking of large marine vessels 

      Kristiansen, Raymond; Ørke, Henning; Gravdahl, Jan Tommy (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-22)
      In this paper, we address modelling and simulation of dynamics involved in docking of large marine vessels with aid of tugboats, with the aim of providing a tool for improved design of control algorithms for autonomous docking operations. Mathematical models of the docking vessel and tugboats in 3DOF are derived, with a special focus on realistic interactions through towline, contact and friction ...

    • Modified demagnetisation control strategy for low-voltage ride-through enhancement in DFIG-based wind systems 

      Senapati, Manoj Kumar; Nayak, Paresh Kumar; Padmanaban, Sanjeevikumar; Gjengedal, Terje (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-16)
      The large-scale wind energy conversion systems (WECSs) based on doubly-fed induction generators (DFIGs) are very popular in recent years due to the numerous technical and economic benefits. With the increasing penetration level of wind energy, the latest grid codes require the DFIG-based WECSs to remain connected to the grid under grid fault scenarios and deliver the required reactive power into ...

    • A Modified Version of the IEEE 39-bus Test System for the Day-Ahead Market 

      Tricarico, Gioacchino; Wagle, Raju; Dicorato, Maria; Forte, Giuseppe; Gonzalez-Longatt, Francisco; Rueda, Jose Luis (Chapter; Bokkapittel, 2023-03-28)
      Reaching net-zero emissions within the proposed time requires an enormous effort from the energy sector, and it is even more challenging for the electricity infrastructure. This article offers a modified version of the IEEE 39-bus system specifically created to allow zonal day-ahead market (ZDAM) simulations. The system representation is based on the original version of the IEEE 39-bus system but ...

    • Når blir skipsfarten grønn? 

      Hoff, Bjarte; Østrem, Trond (Kronikk; Chronicle, 2018-04-25)
      n av utfordringene i forbindelse med dagens skipsfart er utslipp til luft, hovedsakelig karbondioksid og nitrogenoksider. Disse utslippene er knyttet til oljefyrte forbrenningsmotorer som dominerer dagens skipsflåte. Det er overveiende sannsynlig at det er en direkte sammenheng mellom global oppvarming og utslipp av klimagasser. Utslipp til luft kan også bidra til sur nedbør og svevestøv, for å nevne ...

    • Non-directional Overcurrent Protection Relay Testing Using Virtual Hardware-in-the-Loop Device 

      Pham, Le Nam Hai; Wagle, Raju; Gonzalez-Longatt, Francisco; Acosta Montalvo, Martha Nohemi (Chapter; Bokkapittel, 2023-05-17)
      Protective relays are an integral part of the power grid, making it reliable and secure against abnormal conditions. Hardware-in-the-Loop (HIL) can be employed to test and validate digital protective relay devices in the real-time simulation comprising hardware and software before actual implementation. However, the HIL technique requires a complex and high-cost technical environment consisting of ...

    • Norwegian freshmen engineering students' self-efficacy, motivation, and view of mathematics in light of task performance 

      Rensaa, Ragnhild Johanne; Tossavainen, Timo (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-15)
      We report on 71 Norwegian freshmen engineering students' self-efficacy and motivation in mathematics. Students' responses to five-point Likert scales were analysed across three groups corresponding to different performance levels on a set of mathematical tasks. The groups were investigated to trace differences in self-efficacy, motivation, and the epistemological beliefs about the nature of mathematics. ...

    • Norwegian, Swedish, and Finnish first-year engineering students' motivational values and beliefs about the nature of mathematics 

      Tossavainen, Timo; Rensaa, Ragnhild Johanne; Haukkanen, Pentti (Chapter; Bokkapittel, 2022)
      We report from a Nordic research project that has investigated first-year engineering students in Norway, Sweden, and Finland, and the relationships between their task performance, motivational values, and beliefs about the nature of mathematics. The present paper focuses on the covariance between their motivational values and beliefs from the perspectives of gender and nationality. The results ...

    • A note about frequencies being close or amplitudes being small in frequency analysis 

      Rensaa, Ragnhild Johanne (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-10)
      In an earlier paper, an alternative method for how to solve the frequency analysis problem was offered. The object of the present paper is to bring about how to handle situations where the frequencies are close to each other or there is an amplitude that is really small.

    • A Novel Technique to Mitigate the Overlap-Time Effect in Current Source Inverters 

      Sohail, Umer; Østrem, Trond; Hoff, Bjarte (Chapter; Bokkapittel, 2023-08-31)
      Generally, the current source inverter is considered more reliable than the voltage source inverter due to the presence of inductor as an energy storage element on the DC link, but a disruption in the inductor current could significantly risk its reliability. To guarantee the reliable operation of current source inverter, an overlap time must be added to the gate signals of its switches. This ensures ...

    • Ny flåte og elektrifisering – Eksempel på grøne løysingar og utviklinga i dag 

      Hoff, Bjarte (Conference object; Konferansebidrag, 2020)

    • Observations of sunlit N2+ aurora at high altitudes during the RENU2 flight 

      Ellingsen, Pål Gunnar; Lorentzen, Dag Arne; Kenward, David; Hecht, James H.; Evans, J. Scott; Sigernes, Fred; Lessard, Marc (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-24)
      We present measurements of sunlit aurora during the launch of the Rocket Experiment for Neutral Upwelling 2 (RENU2) on the 13 December 2015, 07:34 UTC. The in situ auroral conditions coincide with those of sunlit aurora and were characterised by the 391.4 and 427.8 nm N<sub>2</sub> <sup>+</sup> emissions. A correlation between several auroral wavelengths, as measured by a meridian-scanning ...

    • Optical water types of the Nordic Seas and adjacent areas 

      Aas, Eyvind; Højerslev, Niels Kristian; Høkedal, Jo; Sørensen, Kai (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-05-20)
      A new map of Jerlov's optical water types in the Nordic Seas and adjacent waters at 139 locations, as well as a table with statistical and geographical properties of the vertical attenuation coefficient of downward irradiance at 475 nm, are presented. The data analysis is based on 715 recordings at different stations, at latitudes between 54° and 82°N, and longitudes between 31°W and 49°E, obtained ...

    • Optimal power flow based coordinated reactive and active power control to mitigate voltage violations in smart inverter enriched distribution network 

      Wagle, Raju; Sharma, Pawan; Charu, Sharma; Amin, Mohammad (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-30)
      Voltage violations are the main problem faced in distribution networks (DN) with a higher penetration of inverter-based generations (IBG). Active and reactive power control from smart inverters (SI) can mitigate such violations. Optimal power flow (OPF)-based control provides more accurate operating set points for the coordinated operation of SIs. Therefore, this paper presents a three-phase OPF-based ...

    • Optimal Solutions for Underwater Capacitive Power Transfer 

      Al-Sallami, Hussein; Hoff, Bjarte; Østrem, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-09)
      Capacitive power transfer (CPT) has attracted attention for on-road electric vehicles, autonomous underwater vehicles, and electric ships charging applications. High power transfer capability and high efficiency are the main requirements of a CPT system. This paper proposes three possible solutions to achieve maximum efficiency, maximum power, or conjugate-matching. Each solution expresses the ...

    • Path planning and reactive based control for a quadrotor with a suspended load 

      Corona Sanchez, Jose Juan; Kristiansen, Raymond; Andersen, Tom Stian (Conference object; Konferansebidrag, 2021-06)
      This paper presents a solution to quadrotor cargo transportation, more precisely when cargo is suspended as a sling load. The challenge lies in payload position control and swing attenuation, which we approach by dividing the model into subsystems: attitude quadrotor in free flight, and translational and attitude load dynamics. We propose a solution based on reactive control, in the sense that we ...