Blar i forfatter Artikler, rapporter og annet (elektroteknologi) "Østrem, Trond"

Viser treff 1-13 av 13

    • Conformal Transformation Analysis of Capacitive Wireless Charging 

      Al-Sallami, Hussein Mahdi Yaseen; Hoff, Bjarte; Ellingsen, Pål Gunnar; Østrem, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-30)
      This paper studies the capacitive coupling in a capacitive power transfer (CPT) system designed for charging applications. It proposes mathematical models using the conformal transformation for calculating air-gapped and underwater capacitance and verifies the proposed models using COMSOL multiphysics and measurements. The measured results show that we can achieve nano-farad capacitance ranges ...

    • Deep Adaptive Ensemble Filter for Non-Intrusive Residential Load Monitoring 

      Kianpoor, Nasrin; Hoff, Bjarte; Østrem, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-10)
      Identifying flexible loads, such as a heat pump, has an essential role in a home energy management system. In this study, an adaptive ensemble filtering framework integrated with long short-term memory (LSTM) is proposed for identifying flexible loads. The proposed framework, called AEFLSTM, takes advantage of filtering techniques and the representational power of LSTM for load disaggregation by ...

    • Framework for Modeling and Simulation of Household Appliances 

      Bjerknes Nilsen, Christian; Hoff, Bjarte; Østrem, Trond (Peer reviewed; Book; Chapter, 2018-12-31)
      This paper describes a framework for simulating household appliances in Simulink. Typical Norwegian household equipment have been analyzed based on their characteristic behavior, to establish the requirement for synthesizing and recreating their current waveform, harmonic currents and phase shift. Both detailed simulation of the current waveform and RMS currents for simulation over longer time periods ...

    • Framework for Modeling and Simulation of Household Appliances 

      Bjerknes Nilsen, Christian; Hoff, Bjarte; Østrem, Trond (Peer reviewed; Chapter, 2018-12-31)
      This paper describes a framework for simulating household appliances in Simulink. Typical Norwegian household equipment have been analyzed based on their characteristic behavior, to establish the requirement for synthesizing and recreating their current waveform, harmonic currents and phase shift. Both detailed simulation of the current waveform and RMS currents for simulation over longer time periods ...

    • Home Load Disaggregation using Deep Learning and Bayesian Optimization: A Case Study in Arctic Climate in Northern Norway 

      Kianpoor, Nasrin; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2023-08-03)
      Load monitoring is an essential task in energy management systems. In this paper, an approach that relies on a long short-term memory (LSTM) model and a discrete wavelet transform (DWT) filter is presented to estimate the energy usage of flexible appliances. In the preprocessing stage, the main features of the aggregated power signal are extracted using DWT. Deep learning methods are very sensitive ...

    • 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. ...

    • 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 ...

    • 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 ...

    • 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 ...

    • A Review of Power Converters for Ships Electrification 

      Al-Sallami, Hussein Mahdi Yaseen; Hoff, Bjarte; Østrem, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-07)
      Fully electric ships have become popular to meet the demand for emission-free transportation and improve ships' functionality, reliability, and efficiency. Previous studies reviewed the shipboard power systems, the different types of shipboard energy storage devices, and the influences of the shore-to-ship connection on ports' electrical grid. However, the converter topologies used in the electrification ...

    • Thyristor based short circuit current injection in isolated grids 

      Hoff, Bjarte; Sharma, Pawan; Østrem, Trond (Peer reviewed; Bokkapittel; Chapter, 2017-02-16)
      This paper proposes a thyristor based short circuit current injector for providing short circuit current in isolated and weak grids, where sufficient fault current to trigger circuit breakers may not be available. This will allow the use of conventional miniature circuit breakers, which requires high fault current for instantaneous tripping. The method has been validated through experiments.

    • Under Seawater Capacitive Power Transfer for Maritime Charging Applications 

      Al-Sallami, Hussein Mahdi Yaseen; Hattori, Reiji; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2023-09-12)
      Underwater capacitive power transfer (CPT) can provide an inexpensive and light electric charging solution with good misalignment tolerance for unmanned maritime vehicles. This paper investigates the effect of the changing of the frequency and the distance on the power transfer and overall efficiency of the underwater CPT system, considering the dielectric losses of the medium. It also proposes and ...