Selaus koulutusohjelman mukaan kokoelmassa VäitöskirjatSchool of Energy Systems, Sähkötekniikka
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Acoustic Emission Testing of Multilayer Ceramic Capacitors
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 25.03.2022)Capacitors are among the three fundamental passive electrical components alongside inductors and resistors. They are found in nearly every electronic circuit, with the function of storing electrical energy and filtering ... -
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 ... -
Analyses and comparison of energy systems and scenarios for carbon neutrality – Focus on the Americas, the MENA region, and the role of geo-technologies
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 23.02.2023)Energy systems underpin the economic growth of nations but are contributing to worsening climate change in the current state dominated by fossil fuels. Transitioning to a fossil-free renewables-based energy system is ... -
Analysing the interplay between business models and sustainable mini-grid ecosystems
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 20.09.2024)Global advancements have been made in improving electricity accessibility, yet persistent challenges remain, particularly in rural areas of sub-Saharan Africa (SSA). Distributed Energy Resource (DER) technologies, notably ... -
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 ... -
Anomaly detection in cyber-physical applications
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 25.05.2023)Anomaly detection is a crucial task in many industrial environments as it enables a safer and more reliable operation of different processes; it is usually seen as a separate process from the industrial system design. ... -
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 ... -
Communications in cyber-physical systems : semantic-functional approach, vulnerability, and physical layer performance
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 27.09.2024)This doctoral dissertation explores semantic knowledge to minimize the use of explicit communication and proposes a tailor-made design for a multiuser network in a cyberphysical system (CPS). A new perspective for radio ... -
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 ... -
Cyber-physical energy management systems
Acta Universitatis Lappeenrantaensis : 1194 (Lappeenranta-Lahti University of Technology LUT, 25.03.2025)Following the global concerns on the growing demand for energy and the increasing rate of environmental emissions, coinciding with the necessity to move toward sustainable energy systems, this doctoral dissertation focuses ... -
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 ... -
Dynamics of the voltage response of PEM water electrolyzer cells: modeling principles and effect on active power
Acta Universitatis Lappeenrantaensis : 1195 (Lappeenranta-Lahti University of Technology LUT, 29.04.2025)Hydrogen produced by water electrolysis using electricity from renewable sources will be a key enabler of the fossil-free economy. As the share of renewable electricity, especially from wind and solar power, will increase, ... -
Effect of impaired power quality on alkaline water electrolyzer performance and controllability
Acta Universitatis Lappeenrantaensis : 1185 (Lappeenranta-Lahti University of Technology LUT, 10.01.2025)Transition from our current fossil fuel-focused energy system to a one based mainly on renewable energy generation will introduce new challenges, the two main ones being the intermittent nature of renewables and the fact ... -
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 ... -
Evaluation of failure mechanisms in electronics using X-ray imaging
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 30.09.2022)Multilayer ceramic capacitors and thick film resistors are widely used in electronic circuits for frequency converters because of their small size and volumetric efficiency. In addition, as a result of the current trend ... -
Evaluation of open-source FEM software performance in analysing converter-fed induction machine losses
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 28.01.2022)Converter-fed induction machines are widely used in variable speed applications. They are renowned for their good controllability, low manufacturing cost, and robustness. These machines are used in various applications ... -
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 ...
