Selaus koulutusohjelman mukaan kokoelmassa VäitöskirjatSchool of Energy Systems, Sähkötekniikka
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Active residential customer in a flexible energy system — a methodology to determine the customer behaviour in a multi-objective environment
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 05.12.2018)The transformation from passive into active end customers in modern energy systems has already started in many European countries, and it is a long process. The first step to engage residential customers to be active actors ... -
Analysis of theory and methodology used in determination of electric motor drive system losses and efficiency
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 23.04.2021)This research is divided into two main parts: loss determination of motors, converters, and motor drive systems and determination of measurement uncertainty. With its accurate measurements and data analysis, the work ... -
Applicability of GaN high electron mobility transistors in a high-speed drive system
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 10.02.2020)Lossless operation and instantaneous switching are properties of an ideal power electronic switch. Wide band gap devices based on gallium nitride (GaN) are the current peak performers in regard to losses and switching ... -
Application of software-defined radio for power-line-communication-based monitoring
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 07.02.2020)Power line communication (PLC) is an established telecommunication technology. A PLC-based communication system has the advantage of securing data. transmission over already existing power line networks. In this way, an ... -
Assessing the applicability of low voltage direct current in electricity distribution : key factors and design aspects
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 20.11.2020)In many countries, the electricity distribution companies are facing the challenge of how to develop the networks effectively and respond to the future needs of societies. Changes in the electricity end use, aging network ... -
Control design issues in grid-connected single -phase converters, with the focus on power factor correction
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 25.09.2020)Electrical equipment is most commonly powered from a mains connection. The mains alternating voltage is rectified, isolated, and regulated in a power supply. The power supply acts as an interface between the mains voltage ... -
Design and control of a permanent magnet bearingless machine
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 29.11.2019)The overall efficiency of high-speed applications can be improved by applying direct drive motor technology. Operating in the high-speed region is a demanding task for the traditional bearing technology. With active magnetic ... -
Energy efficient hydrogen production by water electrolysis
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 28.02.2020)Hydrogen is the most abundant element in the universe. On Earth, it not only forms water molecules, but also commonly combines with carbon into hydrocarbons that power the current world economy. The use of these natural ... -
Energy security evaluation for the present and the future on a global level
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 13.10.2020)Energy Security is a universal concern for all stakeholders and achieving energy security is a crucial objective for all societies. Therefore, energy security became a major part of national security with the ability to ... -
Ferrite Permanent Magnet Hysteresis Loss in Rotating Electrical Machinery
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 15.11.2019)Electrical machines with permanent magnets (PMs) find numerous applications in present energy-efficient technologies. A reasonable compromise in terms of costs and efficiency makes electrical machines with ferrite PMs a ... -
Grid Support by Battery Energy Storage System Secondary Applications
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 13.12.2019)Global developments in renewable energy and energy efficiency of the power consumption present challenges to maintain the frequency stability of the electricity grids. The objective of the research is to investigate how ... -
Identification of magnetically levitated machines
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 16.06.2020)Magnetically levitated machines use magnetic levitation to maintain the separation between the bearing races. They offer various benefits compared with other types of bearings: no contact between the bearing races, the ... -
Improving the DC-DC Power Conversion Efficiency in a Solid Oxide Fuel Cell System
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 29.11.2019)The solid oxide fuel cell (SOFC) is a promising technology for combined heat and power generation as it provides low local emissions, high efficiency, and fuel flexibility. However, the unique electrical characteristics ... -
In-depth analysis of the global power infrastructure—Opportunities for sustainable evolution of the power sector
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 27.11.2020)Over the decades, the power sector has continuously evolved, and the strategy used to provide its service has changed dramatically over time and continues to do so. Therefore, it is of paramount importance to analyse in ... -
LCL Filter Designs for Parallel-Connected Grid Inverters
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 04.12.2018)Power generation has become more dispersed as a result of the increasing popularity of the renewable energy sources, which interface with the utility grid with power electronic converters. Higher power levels can be achieved ... -
Modeling and Analysis of a High-Speed Solid-Rotor Induction Machine
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology, 28.04.2020)Over the last few decades, high-speed electrical machines have become more popular than ever before because of the rapid development of power electronics, magnetic materials, and control engineering. Among all the machine ... -
Modelling and Disturbance Compensation of a Permanent Magnet Linear Motor with a Discontinuous Track
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 11.06.2019)It is very common that industrial applications require linear motion in some part of the process, especially in transportation of products from place to place. Traditional technologies to produce short-distance linear ... -
Optimizing the specific energy consumption of vacuum filtration
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 13.12.2019)Vacuum filtration is applied in solid-liquid separation in a wide variety of industrial processes for instance in the mining, chemical, and paper industries. The main contributor to the considerable energy consumption of ... -
Submersible permanent-magnet synchronous machine with a stainless core and unequal teeth widths
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 30.06.2021)In recent years, permanent magnet synchronous machines (PMSM) have gained popularity owing to their excellent performance compared with other kinds of electrical machines in numerous applications. Furthermore, advances in ... -
The role of renewable energy based seawater reverse osmosis (SWRO) in meeting the global water challenges in the decades to come
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 25.11.2020)Renewable energy (RE) powered desalination is rapidly gaining interest as a means to augment the increasingly stressed global water supply. This thesis introduces and describes the ways in which 100% RE-based seawater ...
