Recent additions

  • Control of Spacecraft Formation with Disturbance Rejection and Exponential Gains 

    Schlanbusch, Rune; Kristiansen, Raymond (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
    We address the problem of state feedback translational motion control of a spacecraft formation through a modified sliding surface controller using variable gains and I^2 action for disturbance rejection. The exponential varying gains ensure faster convergence of the state trajectories during attitude maneuver while keeping the gains small (and the system less stiff) for station keeping. Integral ...
  • All electric battery service vessel - Dynamic modeling of a battery fed IPMSM propulsion plant as a tool for energy estimates and functional description for an energy management system 

    Breines, Anders (Master thesis; Mastergradsoppgave, 2017-06-12)
    "Designing an all-electric battery vessel, knowledge of the dynamic performance of the electrical propulsion plant becomes crucial to produce adequate estimates of needed battery capacity. An energy management system is to control the on-board power flow and ensure energy efficient operation of the vessel. This thesis presents a solution for dynamic simulation of an all-electric battery vessel based ...
  • Ingeniørstudenters bruk av læringsverktøy i et lineær algebraemne : hvilken rolle spiller nettbaserte forelesninger? 

    Rensaa, Ragnhild Johanne (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-11)
    I denne artikkelen diskuteres studentenes bruk av læringsverktøy med spesielt fokus på et nettbasert tilbud. Egne forelesninger i et emne i lineær algebra for master ingeniørstudenter, fjerde år, har blitt streamet og publisert, og jeg har undersøkt hvordan studentene har brukt disse forelesningene. Data er innsamlet første og tredje gang dette ble gjort, og hovedvekten i denne artikkelen er lagt ...
  • 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.
  • En tematisk analyse av hva ingeniørstudenter gjør når de lærer lineær algebra 

    Rensaa, Ragnhild Johanne (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-15)
    Denne artikkelen diskuterer hva ingeniørstudenter gjør når de lærer lineær algebra. Arbeidet inngår i et pågående forskningsprosjekt om læring, og grunnlagsdataene for artikkelen ble samlet inn ved at studentene besvarte et obligatorisk spørreskjema der spørsmålet om hva de gjør når de lærer lineær algebra, ble stilt som et åpent spørsmål. Dataene representerer derfor studentenes egne ord om hva de ...
  • A computational intelligence-based maximum power point tracking for photovoltaic power generation system with small‐signal analysis 

    Senapati, Manoj Kumar; Pradhan, Chittaranjan; Calay, Rajnish Kaur (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-01)
    There are multiple peak functions in its output power characteristic curve of a photovoltaic (PV) array under partial shading conditions (PSCs), the perturb and observe (P&O) may fail to track the global maximum power point (GMPP). Therefore, a reliable maximum power point tracking (MPPT) technique is essential to track the GMPP within an appropriate time. This article proposes a hybrid technique ...
  • Bio‐inspired hybrid BFOA‐PSO algorithm‐based reactive power controller in a standalone wind‐diesel power system 

    Wagle, Raju; Sharma, Pawan; Charu, Sharma; Gjengedal, Terje; PRADHAN, CHITTARANJAN (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-05)
    With an increase in the penetration of renewable energy sources such as wind into the power systems, the operation and control of voltage/reactive power have become more complicated and challenging than ever. As a result, the reactive power imbalance between reactive power generation and demand instigates a reduction in system voltage stability. To deal with the aforesaid scenarios, automatic voltage ...
  • PSO and Kalman Filter-Based Node Motion Prediction for Data Collection from Ocean Wireless Sensors Network with UAV 

    Ho, Tu Dac; Grøtli, Esten Ingar; Johansen, Tor Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-13)
    In this paper, we consider a wireless sensor network of nodes at the sea surface drifting due to wind and sea currents. In our scenario an Unmanned Aerial Vehicle (UAV) will be used to gather data from the sensor nodes. The goal is to find a flyable path which is optimal in terms of sensor node energy consumption, total channel throughput between the UAV and sensor nodes, flight time for the UAV and ...
  • 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 ...
  • 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 ...
  • 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 ...
  • Optimal Volt Var control in Smart Distribution Networks 

    Shamraiz, Shamraiz (Master thesis; Mastergradsoppgave, 2021-05-24)
    Both the generation and transmission power networks are facing new threats and opportunities as the number of distributed energy resources (DERs) grows. Because of the high solar PV penetration, voltage rise and voltage volatility are becoming major problems in the distribution network. Voltage regulating devices (VRDs), such as on load tap changers (OLTCs), phase voltage regulators (SVRs), and ...
  • Designing an Autonomous Racing Drone 

    Trældal, Alexander (Master thesis; Mastergradsoppgave, 2021-05-19)
    In recent years drone racing using human pilots have increased in popularity. This combined with the increased usage of autonomous driving vehicles have sparked a new field of interest which is Autonomous Racing Drones competitions. This thesis explores the field of drone design and avionics with the conclusion of presenting the first Racing Drone prototype that can be used in future work made by ...
  • Continuous Autonomous UAV Inspection for FPSO vessels 

    Andreev, Alexey G. (Master thesis; Mastergradsoppgave, 2021-06-23)
    This Master's thesis represents the preliminary design study and proposes the unmanned aerial vehicle (UAV) -based inspection framework, comprising several multirotors with automatic charging and deployment for 24/7 integrity inspection tasks. This project has three main topics. First one describes the operational environment and existing regulations that cover use of UAVs. It forms the basis ...
  • Optimal bruk av reaktive ressurser 

    Arnesen, Jan Tore (Master thesis; Mastergradsoppgave, 2021-05-18)
    God kontroll av reaktiv effekt er en helt nødvendig del av et velfungerende kraftsystem. Reaktiv effekt er funksjon av spenning og lastvinkel, men er i størst grad påvirket av spenningen under normale forhold. Det finnes mange forskjellige reaktive ressurser i kraftsystemet, og de har forskjellige egenskaper og karakteristikker. Statiske reaktive ressurser er kondensatorbatterier, reaktorer og ...
  • Roach Infestation Optimization MPPT Algorithm of PV Systems for Adaptive to Fast-Changing Irradiation and Partial Shading Conditions 

    Ntiakoh, Nicholas Kakra (Master thesis; Mastergradsoppgave, 2021-05-18)
    Of all the renewable energy sources, solar photovoltaic (PV) power is considered to be a popular source owing to several advantages such as its free availability, absence of rotating parts, integration to building such as roof tops and less maintenance cost. The nonlinear current–voltage (I–V) characteristics and power generated from a PV array primarily depends on solar insolation/irradiation and ...
  • Study & Analysis of Power Switches with reverse voltage blocking capability 

    Mughal, Babur Zaman Khan (Master thesis; Mastergradsoppgave, 2021-05-25)
    This thesis hovers over the basic introduction to Silicon Carbide (Metal Oxide Semiconductors Field-effect Transistor) MOSFET switches and the circuit designing of Current Source Invertors using SiC MOSFET switches. The thesis covers the basic grounds for all the steps needed in the implementation of hardware design for half bridge, full bridge and three phase CSIs in the future. Firstly, a ...
  • Wireless charging of offshore wind service vessels 

    Nilsen, Henrik Fjeld (Master thesis; Mastergradsoppgave, 2021-05-18)
    This report discusses the possibility for wireless charging solutions for electric vessels, with a focus on offshore wind turbine service. Where the charging time is minimal and safety for crew is important. Different types of wireless technologies have been studied, where the Inductive power transfer (IPT) is shown to be the preferred technology. Inductive power transfer (IPT) grants a safe ...
  • Modeling and Analyzing of Inverters for Controlling Voltage and Frequency in an Islanded Microgrid 

    Khan, Mazhar Ali (Master thesis; Mastergradsoppgave, 2021-05-18)
    Recently, the growth of inverter-based generations (IBGs) like solar photovoltaic (PV) and wind turbine generators in the form of microgrids (MGs) has been increasing. However, control of voltage and frequency becomes a challenging task for MGs especially when they operate in an islanded mode, due to the inherent low-inertia feature of IBGs compared to a grid-tied mode where there is a grid support. ...
  • Tethered Quadcopter Control, Simulation and Modeling platform for a small USV 

    Wæringsaasen, Sindre (Master thesis; Mastergradsoppgave, 2021-05-18)
    Maritime Robotics main intent of the thesis is to develop understanding of a small deployable camera platform capable of providing elevated situational awareness for a small USV using a tether. The thesis goes into the state-ofthe-art methods of usage and control of a tethered drone. The thesis goes into the building and operating of the QAV250 Pixhawk 4 mini drone and making a drone simulation ...

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