Browsing NTNU Open by Author "Nøland, Jonas Kristiansen"
Now showing items 1-20 of 29
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A Non-normal-mode Marginal State of Convection in a Porous Box with Insulating End-Walls
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Journal article; Peer reviewed, 2019)The 4th order Darcy-Benard eigenvalue problem for the onset of thermal convection in a 3D rectangular porous box is investigated. We start from a recent 2D model for a rectangle with hand-picked boundary conditions defying ... -
A Non-normal-Mode Marginal State of Convection in a Porous Rectangle
Tyvand, Peder A.; Nøland, Jonas Kristiansen; Storesletten, Leiv (Journal article; Peer reviewed, 2019)The fourth-order Darcy–Bénard eigenvalue problem for onset of thermal convection in a 2D rectangular porous box is investigated. The conventional type of solution has normal-mode dependency in at least one of the two spatial ... -
An Analytical Model for Detailed Transient Fault Analysis of Doubly-Fed Induction Machines
Maurer, Frederic; Nøland, Jonas Kristiansen (Chapter, 2020)This paper presents an exact analytical solution to the two-phase and three-phase short-circuit events of the doubly-fed induction machine (DFIM). The contribution is intended to strengthen the predictability of DFIMs under ... -
Analytical-Based Iron Loss Assessment in the SPM Slotless Machine Stator Core
Leandro, Matteo; Nada, Elloumi; Tessarolo, Alberto; Nøland, Jonas Kristiansen (Chapter, 2020)The use of slotless machines has acquired growing interest when features such as low vibrations and noise, along with low losses at high speed, are required. However, a careful assessment of the iron losses in the stator ... -
An Approach for Optimal Pre-Conditioning of the Analytical Field Solution of Slotless PM Machines
Leandro, Matteo; Nøland, Jonas Kristiansen (Peer reviewed; Journal article, 2021)Analytical modeling of electrical machines has the advantage of remarkable computational efficiency when compared with finite element analysis (FEA). This is especially important for slotless topologies, as they are well ... -
Electrical Machines and Power Electronics for Starter-Generators in More Electric Aircrafts: A Technology Review
Nøland, Jonas Kristiansen; Leandro, Matteo; Suul, Jon Are Wold; Molinas Cabrera, Maria Marta; Nilssen, Robert (Chapter, 2019)Safety-critical power conversion systems play a major role in the paradigm shift towards more electric aircraft (MEA) architectures. This paper reviews the electrical machines and their power electronic systems that are ... -
Enhanced Power Capability of Generator Units for Increased Operational Security using NMPC
Øyvang, Thomas; Nøland, Jonas Kristiansen; Sharma, Roshan; Hegglid, Gunne John; Lie, Bernt (Journal article; Peer reviewed, 2019)The ever-increasing penetration of intermittent energy sources introduces new demanding operating regimes for the bulk power generation in the power grid. During a worst-case power system disturbance scenario, the generator ... -
Excitation System Technologies for Wound-Field Synchronous Machines: Survey of Solutions and Evolving Trends
Nøland, Jonas Kristiansen; Nuzzo, Stefano; Tessarolo, Alberto; Alves, Erick Fernando (Journal article; Peer reviewed, 2019)Wound-field synchronous machines (WFSMs) are included in the majority of large power generating units and special high-power motor drives, due to their high efficiency, flexible field excitation and intrinsic flux weakening ... -
Future Operational Regimes of Bulk Power Generation in The Era of Global Energy Transition: Grid Codes, Challenges and Open Issues
Nøland, Jonas Kristiansen; Leandro, Matteo; Nysveen, Arne; Øyvang, Thomas (Chapter, 2020)This paper explores the effects of the ongoing energy transition on the classical bulk power generation. The rapid increase in renewable penetration changes the role of grid-connected generators significantly. Large machines ... -
High-Power Machines and Starter-Generator Topologies for More Electric Aircraft: A Technology Outlook
Nøland, Jonas Kristiansen; Leandro, Matteo; Suul, Jon Are Wold; Molinas Cabrera, Maria Marta (Peer reviewed; Journal article, 2020)More electric aircraft (MEA) architectures consist of several subsystems, which must all comply with the settled safety requirements of aerospace applications. Thus, achieving reliability and fault-tolerance represents the ... -
Hydrogen Electric Airplanes: A Disruptive Technological Path to Clean Up the Aviation Sector
Nøland, Jonas Kristiansen (Peer reviewed; Journal article, 2021)Recently, the COVID-19 pandemic has been a painful reminder of the vulnerability of the aerospace industry. It is currently facing challenges with costs, expensive fuels, and carbon emissions. In recovering the industry, ... -
Laterally Penetrative Onset of Convection in a Horizontal Porous Layer
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Peer reviewed; Journal article, 2020)The onset of Darcy–Bénard convection in an unlimited horizontal porous layer is studied theoretically. The thermomechanical boundary conditions of Dirichlet or Neumann type at the lower and upper plane are switched from ... -
Maximum Torque Density Limit for Surface-Cooled SPM Machines
Bocchese, Andrea; Nøland, Jonas Kristiansen; Bianchi, Nicola; Noddeland, Børge; Røkke, Astrid (Chapter, 2020)The aim of this work is to find the maximum torque density limit of a surface cooled SPM machine. In this paper, an analytical and a FEM-based model are developed under some theoretical conditions. Both models consist of ... -
Non-normal-Mode Onset of Convection in a Vertical Porous Cylinder
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Peer reviewed; Journal article, 2020)This is the first study reporting a full three-dimensional (3D) non-normal-mode onset of convection in a porous medium. In this paper, the onset of thermal convection in a vertical porous cylinder is investigated theoretically. ... -
Online parameter identification of synchronous machines using Kalman filter and recursive least squares
Alves, Erick Fernando; Nøland, Jonas Kristiansen; Marafioti, Giancarlo; Mathisen, Geir (Chapter, 2019)This paper investigates and implements a procedure for parameter identification of salient pole synchronous machines that is based on previous knowledge about the equipment and can be used for condition monitoring, online ... -
Onset of Convection in a Triangular Porous Prism with Robin-Type Thermal Wall Condition
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Journal article; Peer reviewed, 2019)This paper investigates a peculiar case of thermal convection in a vertical porous prism with impermeable and partially conducting walls. We facilitate the analysis in the numerical finite-element environment alongside ... -
Onset of Convection in Two-Dimensional Porous Cavities with Open and Conducting Boundaries
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Journal article; Peer reviewed, 2021)The onset of thermal convection in two-dimensional porous cavities heated from below is studied theoretically. An open (constant-pressure) boundary is assumed, with zero perturbation temperature (thermally conducting). The ... -
Oscillatory Convection Onset in a Porous Rectangle with Non-analytical Corners
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Peer reviewed; Journal article, 2020)The analytical theory on Darcy–Bénard convection is dominated by normal-mode approaches, which essentially reduce the spatial order from four to two. This paper goes beyond the normal-mode paradigm of convection onset in ... -
Oscillatory Non-normal-Mode Onset of Convection in a Porous Rectangle
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Journal article; Peer reviewed, 2019)A special case of the fourth-order Darcy–Bénard problem in a two-dimensional (2D) rectangular porous box is investigated. The present eigenfunctions are of non-normal-mode type in the horizontal and vertical directions. ... -
Peaked sloshing in a wedge container
Tyvand, Peder A.; Nøland, Jonas Kristiansen (Peer reviewed; Journal article, 2021)Finite-amplitude free-surface flow in a wedge container is investigated analytically. We study a motionless standing wave of pure potential-flow acceleration with maximal amplitude where its right-angle surface peak falls ...