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Smart styrning av elförbrukning i ett hushåll - Smart Control of Household Electricity Consumption
No full textSammanfattning
Detta projekt har med hänsyn till det globala läget med ökad komplexitet av elnätet och mängden elproducenter i form av solpaneler, försökt bidra till att hjälpa konsumenter optimera sin elförbrukning. Detta har utförts med utgångspunkt i ett befintligt öppen-källkod optimeringsprogram vid namn EMHASS, utvecklat för det populära smart home programmet Home Assistant. Syftet med projektet har varit att vidarutveckla och anpassa EMHASS för Sverige och framtidsförsäkra programmet genom att utveckla funktioner för optimering av V2X laddning, samt implementering av en ny optimeringsmodell anpassad för de nya effekttariffs abonnemangen som införs. Resultaten för projektet tyder på att utvecklingen har varit framgångsrik, och att de satta målen uppnåddes. Detta då EMHASS nu kompletterats med de önskvärda funktionerna i form av V2X optimering och en ny optimeringsmodell som tar hänsyn till effekttariffer. Då programmet och de tillägg som gjort under projektet är fullt modulär, är framgångarna av det här projektet en stabil grund för användare att utveckla vidare på, och även fast de utvecklade funktionerna för tillfället har brister är de fullt dugliga att utgå från vid styrning av sin elförbrukning.
Abstract
This project, in light of the global situation with increasing complexity of the electricity grid, and the growing number of electricity producers in the form of solar panels, has aimed to help consumers optimize their power consumption. This was carried out using an existing open-source optimization program called EMHASS, developed for the popular smart home platform Home Assistant. The purpose of the project has been to further develop and adapt EMHASS for Sweden, and to future-proof the program by developing features for V2X charging optimization, and implementing a new optimization model tailored to the new power tariff subscriptions being introduced. The results of the project indicate that the development has been successful, and that the set goals were achieved. EMHASS has now been complemented with the desired features in the form of V2X optimization, and a new optimization
model that takes power tariffs into account. Since the program and the additions made during the project are fully modular, the successes of this project provide a solid foundation for further development by users, and even though the developed functions currently have some shortcomings, they are fully adequate as a starting point for managing a households power consumption
Judgement & Decision-Making in High-Risk Maritime Search and Rescue Operations
No full textIn maritime Search and Rescue (SAR) operations, decisions must often be made quickly, under pressure, and with incomplete information. This study investigates how experienced maritime
professionals, specifically On-Scene Coordinators (OSCs), make decisions and judgments during simulated SAR scenarios. By applying psychological theories such as dual process
theory, naturalistic decision-making (NDM), and ecological rationality, the research explores the interplay between intuition, analytical reasoning, experience, and heuristics in high-risk
environments.
Data were collected through full-mission bridge simulations, post-simulation interviews, and observation notes, and analysed using thematic coding and an abductive approach. The findings
show that intuitive strategies were not only prevalent but often highly effective. Heuristics, recognition-based judgments, and shared mental models shaped the decision-making more than
formal analysis. At the same time, analytical processes were also engaged. The study challenges the notion that intuitive decision-making is inherently flawed and emphasises the
importance of structured experience and reflective training in developing safe and adaptive expertise.
This research contributes to maritime safety by highlighting the cognitive foundations of realtime decision-making and offers practical insights for the design of training environments,
leadership development, and future revisions of operational guidelines
Maximum Percent of Post-Consumer Recycled Polypropylene in an Interior Hard Trim Panel
No full textThis study examines the influences PCR PP has on mechanical properties, aesthetics,
CO2 footprint, and the effects from aging. The purpose of the project is to aid
Volvo Cars in updating their material composition of hard trim interior panels by
recommending a suitable percentage of PCR PP to use. The investigated materials
have been 30% PIR PP, 30% PCR PP, 40% PCR PP, 50% PCR PP, 60% PCR PP,
and 70% PCR PP with the same amount of additives. To understand this influence,
methods such as aging, tensile testing, impact testing, differential scanning
calorimetry, perceived quality assessment, and CO2 footprint calculations were performed.
The findings indicate that the mechanical properties are strongly limited by
the impact strength, which decreases with the amount of PCR PP. This limits the
recommendation for Volvo Cars to 30% PCR PP to be used. Regarding appearance,
the perceived quality assessment shows that a switch to the highest material studied,
70% PCR PP, is possible. The tests performed present that aging for 500h and
1000h affects the crystallinity, resulting in varied outcomes for the studied mechanical
properties. The CO2 footprint overall decreases with the amount of PCR PP
content. Although, between 30% PIR PP and 30% PCR PP there is an increase in
the CO2 footprint. Further studies should explore the effects on the full components
instead of material samples, along with additional tests of the same kind as those
conducted to further strengthen the results
Optimization Method Analysis for Tidal Turbine Blade Design
No full textAs demand for green energy increases, Minesto AB produces marine technology for renewable tidal energy solutions. Underwater turbines are used to harness the energy of ocean currents caused by tidal movements. To maximize the electricity generation, the design of the turbine is crucial. The purpose of this thesis project is to study the optimization problem related to a turbine model developed by Minesto AB. The turbine performance for different blade geometries was estimated by calculating the power and thrust coefficients (C_P and C_T ) based on results from computational fluid dynamics (CFD) simulations in the software OpenFOAM. The former coefficient relates the generated to the total available power, and the latter the thrust force to the water flow momentum, and the primary focus was to maximize C_P and the ratio C_P/C_T . There were 18 parameters to be optimized,
related to the geometry of the turbine, including chord lengths, and angles defining the bend and rotation of the blade. The optimization methods tested and analysed were Nelder-Mead, NSGA-II, simulated annealing, and Bayesian optimization with Gaussian processes. The methods were implemented primarily in Python with different settings and operators, and combinations of the methods were also tested. Initially, the optimization was focused on exploring the parameter space, and the maximum power coefficient was found to be C_P = 0.3902. The final goal was to minimize the number of CFD simulations needed to find the optimum, by identifying and implementing the most effective algorithm.
The project found that, for a constant parameter space, Bayesian optimization is the most efficient individual method, and reliably produces results close to the overall maximum C_P within about 260 simulations, or about 30 h. However, combining it with NSGA-II and Nelder-Mead can be advantageous
Life Cycle Assessment of Bipolar Plates in Fuel Cell Electric Vehicle Applications
No full textThis thesis investigates the environmental impact of two types of bipolar plate (BPP) materials used
in fuel cell electric vehicles (FCEVs): composite and metallic based BPPs. In total, one steel and four
composite BPPs were compared, two biobased and two state-of the-art BPPs.
Using the Life Cycle Assessment (LCA) methodology in accordance with ISO 14040/44 standards, the
study evaluates cradle-to-gate impacts across several categories including global warming potential,
human toxicity, acidification, and abiotic resource depletion. The data used to model the production
of the composites, was from both primary and secondary sources. The metallic BPP data was
gathered from secondary sources such as Ecoinvent and literature. OpenLCA was used to model the
systems, with a functional unit of 1 kW power output for comparability. This work was carried out
in collaboration with the public project BioBPP 2, focused on developing renewable bipolar plates for
sustainable fuel cell technology. Results show that the bio-based BPP offers significant potential for
environmental impact reduction compared to the other materials. Furthermore, a future scenario with
local graphite mining would provide even grater environmental impact reductions. These findings aim
to provide valuable insights for stakeholders and support future material development for sustainable
fuel cell systems
Potential and Design for Head-Up Displays in Commercial Trucks
No full textThis thesis explores the potential with Augmented Reality Head-Up Displays (AR-HUDs) in commercial trucks, with a specific focus on the driver’s perspective. Through research and interviews, the project investigates if and how AR-HUDs can be used to enhance safety, usability, and personalisation in the truck. The report describes the development process and presents the outcome: a conceptual interface of an AR-HUD featuring different modes for different driving situations
Electric machine loss measurement and modeling - PWM versus sinusoidal feeding
No full textAbstract
As the electrification of the automotive industry continues, the importance of high efficiency electric machines increases significantly. The ability to accurately predict the efficiency and losses in the designing stage is therefore essential. This thesis studied the degradation in magnetic properties in silicon steel strips cut with different widths. These pieces were then used to develop a model to implement manufacturing effects due to cutting in to the electric machine simulations to more accurately model the iron losses. The simulations were fed with both a sinusoidal current and a pulse width modulated voltage feeding to compare the effect of the different feeding types on top of the cutting degradation effect, and compared with
each other. For all points simulated, the core losses increased when a layer of degraded material closest to the cut edges of the stator was used, up to 25% with the sinusoidal feeding. For the pulse width modulation case, five different operating points were simulated, showing an increase in core losses of up to 7% when using degraded material. Comparing the effect the feeding types had versus each other, the pulse width modulation fed simulations had core losses up to 258% higher than the sinusoidally fed case. One measurement of the actual machine was compared with the pulse width modulated feeding simulations where the difference between losses was 6.7%, showing promise in the model for the simulated points
Development of Generic Simulation Objects in Discrete Event Simulation - Enabling Automatic Generation of Simulation Models using Process-Related Data from a PLM System
No full textThe automotive and manufacturing industries are undergoing a transformation with the adoption of advanced simulation and data management systems. The practice
of manually modeling simulation models is time-consuming and costly, which limits the feasibility of simulation studies when resources are insufficient.
This master thesis thereby investigates how process-related data from a PLM system can be utilized to automatically generate generic simulation objects that accurately
represent manufacturing systems. It further explores the possibilities of integration between PLM and DES applications, presenting several concepts for automatic generation and PLM/DES integration.
The findings from the master thesis shows that automatic generation of generic simulation objects is achievable and effective in reducing manual efforts. Additionally, centralizing data in a single
location improves input data management and enhances compatibility with different DES applications. To demonstrate this, a generic simulation tool and user-interface were developed. The solution provides
improved interoperability opportunities between PLM and DES environments, reducing manual work and increasing efficiency for simulation engineers
Investigation of HV-LV Isolated DC-DC Converter Topologies for Automotive Applications
No full textAbstract
In this work the design of isolated DC/DC converter such as phase shifted full bridge with three different secondary topologies full bridge (FB), center tapped (CT) and current doubler(CD) are discussed which are to be used in auxiliary power module (APM) to power the LV battery in an electric vehicle. The converters are designed for a full load power of 7500 W and an input voltage range of 370 V - 920 V to achieve regulated output of 15 V at an operating frequency of 100 kHz. The main work involves the design of transformer, inductor, component
level loss analysis and estimation of efficiency of the converters at various loads and input voltages. Phase shift is a modulation technique used to control the operation of the switches
in the primary where all the switches in the primary operate for a fixed duty cycle of 50% but with a phase shift. The phase shift depends on the input voltage and turns ratio of the transformer. In this topology zero voltage switching (ZVS) is achieved through the leakage inductance of the transformer so turn on losses are zero but turn off losses are unavoidable. Silicon carbide (SiC) MOSFET’s are used in the primary and Silicon (Si) MOSFET’s are used in the secondary. Several design considerations were taken into account such as paralleling of switches on the secondary, variation of on state resistance ,Rds,on , junction temperature rise of the switches. All the converters were simulated in MATLAB/Simulink to find the currents in the components to estimate the conduction , switching losses in MOSFET’s, copper losses in transformer and inductor.The waveforms of the converters are verified theoretically and through simulations. Comparison of the converters based on the total losses and efficiency is done at the end of this work which made it evident that the PSFB-CT has a better performance at low load PSFB-CD has a better performance at high load. Further investigationss and comparison of topologies such as traditional half bridge and LLC can be considered.
Different topology architectures involving interleaving/paralleling of the power stages or components can be considered to improve the performance