[dipl] Sähkötekniikan korkeakoulu / ELEC
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Item Analyzing Future Reinforcement Needs Of the Finnish Transmission System Considering Hydrogen Production(2024-03-11) Sorjamäki, Joonas; Kasmaei, Mahdi; Millar, Robert; Sähkötekniikan korkeakoulu; Kasmaei, MahdiWith new challenges and ambitious carbon neutrality goals, hydrogen is becoming an essential part of the green transition. Hydrogen can be produced via electricity. The idea is to generate clean electricity and use it to produce hydrogen through electrolysis. The increased need for electricity production requires building more electricity generation capacity. Furthermore, network investments need to be made to cover the higher electricity transmission needs. The expansion of generation and transmission capacities can be done cost-effectively if the expansion plan is obtained by solving an appropriate optimisation problem. In this thesis, an optimised plan for the increase in generation and transmission capacities is made for the simplified Finnish transmission network. Scenarios, published by Fingrid, are used as the baseline for the demand growth in this thesis. Altogether, six scenarios are simulated, and their results are presented in this thesis. The model of the Finnish transmission network used in this thesis has been prepared at Aalto University. Due to time constraints, the method for arriving at the combined generation and transmission plans used in this thesis is simple and seen as a starting point for future works. The method is static, deterministic, and centralised. Furthermore, many things often considered in grid planning, like the N-1 criterion, are not taken into account. The model used in this thesis is coded and simulated in GAMS software. The main outcomes of the modelling efforts made in this thesis are based on six generation and transmission expansion plans for the six different scenarios modelled in this thesis. Four of the scenarios are taken directly from Fingrid and two more scenarios are also devised. The idea does not constitute a complete plan for future network expansion, as the modelling made in this thesis is simplified. While some conclusions are drawn from the results of the simulations, the simplicity of the method needs to be considered. The main conclusions of the thesis, along with the network plans themselves, are that if only cost-effectiveness is to be maximised and other ongoing discussions and some technical constraints to be kept aside, nuclear energy should be given preference over other energy sources, and other thermal power plants should be phased out. But by considering all the different aspects, the results will be different. Also, the demand in one node should be covered as much as possible with the generation in that same node to minimise network investment needs.Item Boundary extension for visual views in virtual reality(2024-03-11) Pullinen, Akseli; Henriksson, Linda; Sähkötekniikan korkeakoulu; Henriksson, LindaBoundary extension is a phenomenon describing a tendency for people to mistakenly add new information to the borders of an image they are trying to recollect, beyond the borders of the original image. This effect is thought to reflect a spatial bias of our memory for visual scenes, but it remains unclear whether the results generalize from images to more naturalistic viewing behaviour. The goal of this thesis was to address this question through an experiment using naturalistic virtual reality environments as visual stimuli. This novel experiment was developed in-house, leading to an additional goal for the project to be the development of boundary extension research methodology for virtual reality. At each trial, the subjects (N = 60) were first allowed to visually explore a virtual room for 5 seconds. Soon after the viewing, they were put back into the same room, but to a different distance away from the wall they had been previously facing. The subjects then used a controller to move to the same location from which they had originally viewed the room. Boundary extension was thought to emerge if a tendency could be found for the subjects to stop moving when the distance between them and the wall they had originally faced exceeded the distance during the initial viewing. Boundary extension was found in scenarios where the subject needed to move closer to the wall in order to reach their original location, and also in any scenario where the visual exploration was done with the subject being close to the wall. These results are in accordance with previous research and suggest that the phenomenon of boundary extension generalizes to real-world scene perception.Item Analysis and evaluation of systematic test management frameworks in agile embedded software development(2024-03-11) Liljeström, Oskar; Korhonen, Janne; Sähkötekniikan korkeakoulu; Vujaklija, IvanAgile software development practices, such as continuous integration and deployment, are becoming more common within the embedded software development area. These practices generally require extensive testing of the software throughout the entire development process. The particularities of testing embedded system software further complicate the process, as the tests are often hardware-specific and tests can take relatively long to execute. To make sufficient testing feasible, developers make use of various testing and automation tools to reduce the workload. However, because each tool serves a specific purpose, information related to the testing progress of a software project is easily split up over multiple plat-forms. This can make it hard to get a complete overview of the project’s test and requirements coverage, and gathering the data and reporting on it takes manual work and bears the risk of human error in the results. In order to ease the integration of different test management tools in-to the software testing workflow, this thesis develops a framework for automating the transfer of test results and requirements information between different testing tools. To evaluate the functionality of the pro-posed framework, the thesis implements a functioning system based on the framework guidelines and puts it to use in a live testing environment. The implemented system offers significant improvements to the speed and reliability of test status reporting and requirements validation, compared to previous solutions. A weak point in the developed framework is the configuration work required to set up the different tools before information can be shared between them. Future research could investigate whether it’s possible to also automate the configuration of one tool based on the configuration of another.Item Integrating open-source computer and network monitoring software to an automation supervision system(2024-03-11) Koskinen, Marko; Baumann, Dominik; Sähkötekniikan korkeakoulu; Baumann, DominikThis thesis tackles an issue regarding automation supervision system monitoring, where the monitoring tools have differing configuration setups. This thesis focuses on creating a common option for the monitoring tools, that can be used with any automation supervision system. The problem is approached by using external monitoring software, and to make the solution highly integrable, a separate integration interface was created. This thesis found a suitable monitoring solution, Zabbix, among a selection of researched open-source network monitoring software. Zabbix is a well-rounded solution that has everything in one package. The integration interface was then created using Python 3. It utilizes Zabbix application programming interface and Modbus server for connecting the two software together. As a result, this created a working combination of monitoring and integrability that enables monitoring of the network and hardware in any automation supervision system.Item Feature preview deployments as part of the CI/CD pipeline in software development(2024-03-11) Mäkinen, Joonatan; Törnroos, Juha; Sähkötekniikan korkeakoulu; Vanhanen, Jari-PekkaThis thesis explores the implementation and impact of an enhanced Continuous Integration/Continuous Delivery (CI/CD) pipeline within a software development team. Rooted in the canonical action research framework, the study progresses through diagnosis, action planning, intervention, evaluation, and learning phases. As a result of these phases, the particular CI/CD pipeline utilized by a real-world software development team sees the addition of an automated feature preview deployment system. This enables each pull/merge request of new software features to be previewed in a testing environment to aid the code review process. This improvement demonstrates notable benefits, enhancing development efficiency, internal and external collaboration of the team, and scalability of a project with a growing team. However, the solution presented in the thesis might also not be applicable for every software development project with differing deployment configurations. The research also identifies future paths, such as enabling feature branch deployments already prior to pull/merge request phase and an automated release process accommodating previous releases in the same testing environment. The implications for practice highlight the importance of suitable CI/CD adoption, balancing automation benefits with precision in software quality. Future research suggestions include exploring new CI/CD configurations, organizational shifts caused by adoption, and staying alongside evolving industry trends. Therefore, this thesis essentially contributes to the ongoing consideration on CI/CD practices, offering practical insights and directions for further exploration in the realm of software development.Item LIDAR-based Semantic Segmentation for Navigation in Semi-Dynamic Environments(2024-03-11) Tuomisto, Jaakko; Pajarinen, Joni; Sähkötekniikan korkeakoulu; Pajarinen, JoniThe adoption of autonomous mobile robots across industries has increased the demand for sophisticated navigation systems capable of operating in complex and dynamic environments. To address the need, this thesis presents the development and evaluation of a navigation system for mobile robots. In particular, the focus is on managing the semi-dynamic obstacles of the environment, which are obstacles that can be static for long periods of time but will still occasionally move. Examples of semi-dynamic obstacles include temporary construction barriers or parked vehicles. These semi-dynamic obstacles pose a challenge for autonomous navigation, as they are often erroneously mapped as static obstacles. This causes navigation systems to operate based on incorrect assumptions about obstacle locations, which can cause the robot to take unnecessary detours or become trapped. To address the challenge, this thesis proposes utilizing deep-learning semantic segmentation applied to LIDAR data to differentiate between temporarily and permanently blocked paths. The semantic segmentation model employed in this system is trained on a custom synthetic dataset, and operates in real time as the robot explores the environment. The acquired semantic information is combined with three-dimensional occupancy mapping, A*-based path planning, and recovery behaviors for reacting to movements of semi-dynamic obstacles. The system's proficiency in managing semi-dynamic obstacles is validated through simulated experiments. Furthermore, the system is tested using the real-world Boston Dynamics Spot robot.Item Automatic testing for continuous delivery in production simulation software(2024-03-11) Glasin, Pyry; Antonenko, Jevgeni; Sähkötekniikan korkeakoulu; Vyatkin, ValeriyProduction simulation software has become an important tool in the automation industry to visualize and simulate complex systems. At the same time, continuous delivery has become an important practice in the software industry that improves productivity, communication, and project predictability. Automatic testing is a key factor in enabling continuous delivery, and this study examines improving automatic testing of production simulation software with the goal of enabling continuous delivery. A set of common characteristics for production simulation software are defined, and a literature review is conducted to find out what testing approaches are proposed in research to test software with similar properties. The applicability of the results for testing these types of software are then evaluated. Finally, one of the approaches is selected and implemented to test the Visual Components simulation software. This study concludes that while no comprehensive testing solution was found, there are several approaches that could be adapted to test various aspects of production simulation software and that the tool selection should be made by evaluating the issues preventing continuous delivery in the organization developing the software. For testing the Visual Components simulation software, a script-based UI testing tool was adapted. Initial results of the implementation show that the tool is able to automate some of the tests that were previously done manually, but a longer evaluation period is needed to observe if the tool has an impact on the release frequency of the product.Item Electrical design of an auroral photometer for nanosatellite applications(2024-03-11) Miettinen, Santeri; Tanskanen, Eija; Keskinen, Sami; Sähkötekniikan korkeakoulu; Ikonen, ErkkiWith the increasing popularity of cubesatellites and nanosatellites, the cost of launching space-based instruments has drastically decreased. This encourages small institutes and corporations to design and develop their own scientific instruments for space applications. This has been one of the driving factors for the Sodankylä Geophysical Observatory (SGO), which is developing its own CubeSat program to help grow the scale of the scientific observations of the observatory. This thesis designs, develops, and electrically tests a prototype of an auroral photometer for nanosatellite applications. The proposed photometer is designed to fly onboard LappiSat-1, the first satellite developed by SGO. The photometer demonstrates the ability to detect auroral emissions by using avalanche photodiodes (APDs) instead of traditionally used photomultiplier tubes. The reverse voltage of the APD is controlled by a microcontroller unit (MCU) to keep the internal gain of the photodiode stable in a temperature-varying environment. The photocurrents produced by the APDs are converted to voltage using a variable-gain transimpedance amplifier. The data is collected using an analog to digital converter and is saved to onboard memory by the MCU. Communication between the satellite platform and the other LappiSat-1 payloads is implemented using a CAN bus.Item Analysis of large solar thermal plant measurement data and evaluation of a solar heat production simulation tool(2024-03-11) Kaur, Laura; Viot, Maxime; Sähkötekniikan korkeakoulu; Lehtonen, MattiThe purpose of this thesis was to produce summary key figures and evaluate the accuracy of the calculation tool based on existing solar plant data. Data from six solar thermal plants was obtained and formatted to be used in the calculation tool. Due to problems with two plants, only four plants were analysed. The data form the plants gave global solar radiation values but diffuse and beam values were needed for the calculation tool. Different models were considered but, in the end, a two-variable regression was made based on Meteonorm water data to calculate the diffuse and beam components for each plant. The results from the calculation tool have some variation when compared to the measured data. That could be partially due to the irradiation splitting method and each data set having missing values. The annual heat production values vary from 2-18%, but when excluding the overly high values, the average comes to 4,75%, which is an accurate enough result. However, since there are some bigger differences in the monthly production values, further analysis should be conducted to understand what causes these differences and if the accuracy could be enhanced.Item Implementing Zero Trust Architecture in Azure(2024-03-11) Katuwal, Arun; Mähönen, Petri; Sähkötekniikan korkeakoulu; Mähönen, PetriCloud computing has become increasingly popular due to the fact that it can deliver computing resources over the internet on a pay-as-you-go basis. However, with the growth of cloud adoption, there is an increased need for strong cybersecurity measures to protect sensitive information and critical assets from cyber threats that are constantly evolving. Due to the distributed nature of resources and the increasing sophistication of cyber threats, such as phishing and brute force attacks that put password use at risk. Fortunately, the necessity for a password is eliminated with Zero-Trust and is the most crucial security approach today. Zero-Trust is an innovative network security model that is quickly gaining popularity. The key concept is that every request must be evaluated and approved because no trustworthy sources are available; everything must be rigorously verified before providing access. Although numerous studies have investigated the implementation of Zero Trust Architecture (ZTA), few have focused on cloud environments, specifically on Azure Virtual servers. The implementation of Zero-Trust security measures was studied and applied to the Azure environment, resulting in a strong and reliable security model. Furthermore, system administrators have been granted conditional access to establish a secure communication channel with the Azure environment from the Internet while multi-factor authentication has been utilized. A secure environment was established in Azure by implementing the settings and methodologies discussed for zero-trust. The setup used for the implementation was a simple one compared to the complex infrastructure an organization can have. This thesis showed that it can be a lengthy process and time-consuming for one person to implement zero-trust, however, most of those configurations were one-time setup and can be automated when needed. Although implementing the zero-trust model may vary depending on an organization's unique needs, the fundamental principles; verify explicitly, use least privileged access, and assume breach always remain at the core of this security strategy.Item Using NR Sidelink for UAV Swarm Internal Communication(2024-03-11) Varonen, Matias; Tirkkonen, Olav; Sähkötekniikan korkeakoulu; Tirkkonen, OlavThe focus of this thesis is to provide an up-to-date overview of UAV device-to-device communications using NR Sidelink. The main objective is to identify the enabling factors for establishing an internal communication network inside a drone swarm, using the 3GPP standardized NR Sidelink communications. The thesis mainly focuses on the study of functionalities included in the Sidelink standard. It includes a literature review that higlights the functionalities in the Sidelink standard while evaluating its suitability for UAV swarm internal communications. Moreover, MATLAB simulations were implemented to estimate the required update frequency for routing within a multi-hop network when applied to the UAV swarm internal communications. The results reveal that the NR Sidelink standard has favorable physical and link layer procedures for UAV communications inside a swarm. However, the standard lacks certain functionalities required to fully enable internal communications, such as support for beamforming or network management. The NR Sidelink standard does not define, but enables network layer routing, and this has been studied through simulation. Comparison of simulation results against the capacity of NR Sidelink indicates that the control overhead does not overly burden the available resource pool and the updates for the routing decrease the required transmission power.Item Implementation and Benefit Analysis Framework for Attended Robotic Process Automation(2024-03-11) Hartman, Benjamin; Tuominen, Santeri; Sähkötekniikan korkeakoulu; Vujaklija, IvanBusiness process automation (BPA) is a key strategy for companies aiming to optimize business processes, reduce costs, and increase employee work satisfaction. Robotic process automation (RPA) has in recent years become one of the most widely used methods of BPA, as it offers advantages such as lower cost, higher agility, and wider scope of use compared to traditional IT solutions. RPA involves the use of software robots that can perform repetitive, mundane, and boring tasks, either autonomously or in real-time collaboration with human workers. These two modes are referred to as unattended and attended RPA, respectively. Unattended RPA has long been the more popular of the two, but attended RPA has been gaining popularity in recent times as its human-robot interaction abilities open up a plethora of novel possibilities in automating business processes. While there are resources on selecting suitable processes for unattended RPA readily available, there is a clear lack of guidance on how attended RPA is best utilized and what processes it is suitable for. To this end, this thesis aims to address this gap to enable companies to use attended RPA to its full capabilities, allowing for a higher grade of enterprise automation. To achieve this, a framework is developed for evaluating the suitability of a process for attended RPA based on different evaluation criteria. The framework was designed by interviewing RPA experts about their conceptions and experience of attended RPA, from which key features of attended RPA processes were extracted and formulated into a framework. The main themes in the evaluation framework include human interaction, criticality and scale. To validate the work, the framework was used in a test evaluation, which displayed its functionality as a tool for assessing the suitability for attended RPA in business processes.Item GPT-3.5 Turbo Evaluation Tool(2024-03-11) Oltean, Iulia; Manner, Jukka; Sähkötekniikan korkeakoulu; Manner, JukkaThis study investigates the challenges and implications associated with differentiating between computer-generated and human-generated text, with a specific focus on the utilization of the GPT-3.5 Turbo model. It explores the impact of artificial intelligence (AI) across various domains and endeavours to ascertain whether ChatGPT can discern the origin of a given text. The research is motivated by the escalating concern surrounding the misrepresentation of AI-generated text as human-authored, a practice that undermines transparency and integrity, necessitating the development of effective detection and mitigation strategies. Research Question: Can AI-generated text be distinguished from human-generated text, and if so, with what accuracy? The study examines the diverse applications of GPT-3, devises a mechanism to mask the origin of content generated by the ChatGPT-3.5 Turbo model to simulate human authorship, evaluates the efficacy of this mechanism, and proposes enhancements to facilitate the identification of AI-generated content when human-authored content is required. The study reveals that substituting synonyms proves to be a more effective method for concealing AI-generated text than rephrasing. Presently, AI models such as GPT-3.5 Turbo are unable to emulate human writing entirely. Consequently, there is a pressing need to bolster security measures to prevent instances of AI-generated text being misrepresented as human-generated. It is imperative to underscore that while such occurrences are not ubiquitous, unethical practices such as leveraging AI for academic dishonesty are unequivocally condemned. It is important to note that this study has inherent limitations, and future research endeavours will delve into the structural aspects of language, contextual considerations, alternative detection tools, diverse domains such as business and science, and multilingual contexts.Item Low Power information display(2024-03-11) Aumasto, Axel; Töyry, Timo; Sähkötekniikan korkeakoulu; Ruttik, KalleThe power use of battery powered information displays present constraints on the information that is possible to show on low power displays. Public transport information displays show real time departure information. This real time requirement provides challenges for the implementation of battery powered display as the departure information needs to be constantly updated over the air causing continuous energy consumption. Different enabling technologies are presented, most notably ePaper displays, LTE CAT-M1 IoT cellular communications, GraphQL API and ESP32 micro controller unit. The prototype is designed and constructed using these technologies while emphasizing the use of open interfaces. A LiFePo4 battery is used as a power source without external power supply. The software implemented employs various power saving techniques which focus on making the components sleep maximum amount of time that are evaluated using a current measurement setup using a shunt resistor and a digital oscilloscope. Different energy consumption profiles are calculated based on real world data. The display demonstrated a half a year theoretical battery life and provided easy to read display showing real time departure information.Item Integrated Successive Approximation Register Analog-to-Digital Converter with Hybrid Reference(2024-03-11) Nurminen, Antti; Rantala, Arto; Sähkötekniikan korkeakoulu; Ryynänen, JussiA wide range of sensors are utilized in industry and research for various purposes. Typically, the analog sensor readings are processed in a digital format, which requires an Analog-to-Digital Converter (ADC). As new sensors are developed, an integrated ADC block with flexible features assist the design process, as the same ADC block can be included in a variety of sensors as a peripheral circuit. A Successive Approximation Register (SAR) ADC was chosen for this purpose. The SAR architecture allows a wide bandwidth, compatible with many applications, as well as a reasonably high number of bits. However, the number of bits in typical ADCs increases the surface area requirement of the internal Digital-to-Analog Converter (DAC). This thesis reviews SAR ADCs and DAC topologies, consequently proposing a hybrid-type DAC, where both capacitors and resistors are utilized to minimize the chip area. Two versions of the ADC were designed and simulated in Cadence. The designs were fabricated with XFAB 350 nm Complementary Metal-Oxide-Semiconductor (CMOS) process. The chips were then bonded and packaged to be characterized on a test board and setup, designed for the purpose. The measurement results showed the ADC to have attained an Effective Number Of Bits (ENOB) of 6.8 and a Signalto-Noise Ratio (SNR) of 47.2 dB, with a target speed of 1 MegaSamples per second (MS/s), and an active area of 305 × 525 𝜇m2. Through analyzing the results, the critical parts of the design are contemplated, and further improvements are proposed. The management of parasitic elements and the control logic timing are indicated to be the largest sources of errors. For improving the device in the future, a bootstrap circuit and a more robust timing sequence of the control signals are suggested. This thesis was done as a part of a project for VTT Technical Research Centre of Finland with funding from Research Council of Finland.Item FPGA implementation of confidential computing enclave(2024-03-11) Tuovinen, Henri; Järvinen, Kimmo; Jehkonen, Petri; Sähkötekniikan korkeakoulu; Ryynänen, JussiThe use of cloud computing resources has continued to rise over the last decade. Cloud computing enables the use of efficient distributed services. However, data confidentiality cannot be guaranteed in currently used cloud systems shared between different parties. Data confidentiality cannot be guaranteed since the cloud systems use Central Processing Units (CPU) and program code that have well known vulnerabilities. This thesis studies a confidential computing enclave implementation on a Field-Programmable Gate Array (FPGA) that may be a cloud resource. This solution enables performing remote computation securely in an isolated enclave. The studied solution enables a client to upload its data and program code to an enclave securely over the internet. The data is then processed in the secure enclave and the result can only be read by the client. The aim of this thesis is designing and implementing a Proof Of Concept (POC) FPGA confidential computing enclave. The POC is designed utilizing two pre-existing company intellectual property solutions a Transmission Control Protocol / Internet Protocol (TCP/IP) software stack to establish internet connectivity and a Transport Layer Security (TLS) module to establish secure communication. In this thesis an enclave module and a connection controller module are designed and implemented using SystemVerilog Hardware Description Language (HDL). The expected behavior of the designed modules is verified with simulation. Furthermore, the enclave functionality is verified and demonstrated by programming it on an FPGA and communicating with the enclave over a Local Area Network (LAN) using a computer. The POC implementation is deemed successful and feasible to implement in a technical sense. The POC architecture is estimated to be similar to the state-of-the-art and in comparison implements the TLS 1.3 protocol.Item Real-Time Augmented Reality based Operator Assistance for Driving Cut-to-Length Forest Machines(2024-03-11) Satheesan, Arundev; Kukko, Antero; Sähkötekniikan korkeakoulu; Kyrki, VilleThe automation of forestry operations is pivotal for the effective maintenance of forest resources. Forestry operations often involve the utilization of heavy machinery, such as cut-to-length (CTL) machines, designed for tree logging. The success of these operations relies heavily on the proficiency of the operator, highlighting the need for operator assistance. This support aids operators in making real-time decisions, thereby bridging the gap between experienced and inexperienced operators. While automation technologies are prevalent in CTL machines, some lack real-time assistance, and others rely on on-screen displays, requiring the translation of information from offline maps and displays to the real-world. Thus, there is a need for an automation solution that can offer real-time assistance directly to the operator's view. Augmented reality emerges as a fitting solution, where operators view the forest through a Head Mounted Device (HMD), and assistance information, including tree species names and navigation routes, are seamlessly displayed within this view. Therefore, this thesis aims to develop a proof-of-concept system for operator driving with HMDs in outdoor conditions, demonstrating the capability to provide operator assistance information based on the current location of the all-terrain vehicle (ATV) and the gaze of the operator. The platform was implemented on an ATV, facilitating driving with an HMD in a parking area. The goal was to overlay the offline point cloud map of the parking area onto corresponding real-world objects when viewed through the headset. User studies were conducted, and video recordings of the operator's view, coupled with feedback from users, were analyzed to assess the solution's effectiveness in presenting location-based information and overall feasibility. The results indicated that the point cloud partially matched real-world objects for 66.7% of the total duration, with observed discrepancies in depth alignment between point cloud and real-world objects. Ergonomic studies revealed that lighter headsets and improved video quality could enhance operational duration and quality.Item Warehouse control in cloud infrastructure(2024-03-11) Tran, Viet; Muntto, Jarno; Sähkötekniikan korkeakoulu; Visala, ArtoThis thesis examines the shift from traditional on-premises Warehouse control systems (WMS) to cloud-based models, focusing on cloud-based warehouse control. It investigates the commercial feasibility and reliability of adopting cloud technologies in warehouse automation. The advent of software as a service (SaaS) technology and increasing capability of cloud computing offers enterprises to outsource the information technology (IT) infrastructure to the cloud. A Proof of Concept (PoC) model demonstrates practical aspects of implementation, including network connectivity and security measures. A Digital Twin (DT) of a warehouse with virtualized warehouse communication PLC devices is utilized in demonstrating the PoC to work. The case study in this thesis is to manage inventory flow in industrial warehouse through centralized remote warehouse control leveraging cloud technologies. Additionally, the research addresses security concerns and evaluates system reliability, particularly highlighting clustering techniques for enhanced dependability. The findings suggest that despite challenges, cloud-based systems offer significant advantages in scalability, efficiency, and cost-effectiveness, positioning them as a promising direction for the future of warehouse management.Item Alueellisen siirtojenhallinnan tietojärjestelmäkehitystarpeet(2024-03-11) Kerttula, Joona; Oravasaari, Mikko; Sähkötekniikan korkeakoulu; Seppänen, JanneTuulivoiman voimakas lisääntyminen ja sen sääriippuvainen luonne tuo haasteita Suomen sähköjärjestelmän hallintaan. Haasteita syntyy erityisesti järjestelmän stabiiliuden sekä siirtojenhallinnan näkökulmasta. Suomen kantaverkkoyhtiö Fingrid Oyj:n yksi päätehtävistä on ylläpitää kantaverkon käyttövarmuutta sekä kulutuksen ja tuotannon tasapainoa. Siirtojenhallinta on merkittävässä osassa käyttövarmuuden hallinnan prosesseja. Erityisesti tuulivoimakapasiteetin alueellinen keskittymä tuo haasteita nykyisen siirtojenhallinnan prosesseihin ja luo tarpeen alueelliselle siirtojenhallinnalle. Erilaiset tietojärjestelmät ovat kriittinen osa käyttövarmuuden hallinnan prosesseja. Tämän takia siirtojenhallintaan liittyvien tietojärjestelmien asianmukainen kehittäminen on oleellinen osa kantaverkon käyttövarmuuden ylläpitämisessä. Diplomityön tavoitteena oli määrittää minkälaisia tietojärjestelmien kehitystarpeita uudet siirtojenhallinnan haasteet tuovat kantaverkon käyttötoiminnassa. Kehitystarpeita tarkasteltiin käyttöhetken sekä käytön suunnittelun näkökulmasta. Työssä pyrittiin myös kartoittamaan miten tietojärjestelmät pystyvät tukemaan siirtojenhallintaa jatkossa. Tutkimusaineistoa kerättiin teemahaastattelujen avulla. Teemahaastatteluissa haastateltiin siirtojenhallinnan parissa työskenteleviä käytönsuunnittelun sekä kantaverkkokeskuksen asiantuntijoita. Työn aikana kehitettiin asiantuntijahaastatteluissakin esille noussut työkalu. Työkalulla pyrittiin mallintamaan siirtojenhallinnan näkökulmasta haasteellisia alueita, eli tasealueita. Työkalun kehityksessä hyödynnettiin liiketoimintatiedon hallinnan keinoja. Diplomityön tuloksena pystyttiin määrittelemään tietojärjestelmiin liittyvät kehitystarpeet. Kehitystarpeiden määrittelyllä pystyttiin varmistamaan, että alueelliseen siirtojenhallinnan tarpeet on tietojärjestelmien osalta tiedostettu organisaation sisällä sekä ne voidaan ottaa huomioon niiden kehityksessä. Työssä pystytiin myös määrittämään miten nykyisten tietojärjestelmien avulla pystytään tukemaan alueellisen siirtojenhallinnan tarpeita. Kehitetyn työkalun avulla pystyttiin vastaamaan käytönsuunnittelun tarpeisiin tasealueiden mallintamiseksi. Työkalun avulla pystytään jatkossa tukemaan tasealueisiin liittyvää suunnittelua ja päätöksentekoa.Item Long Term Oscillation of Ultra-Low Frequency Oscillations in the Nordic Power System(2024-03-11) Chatterjee, Indrani; Seppänen, Janne; Sähkötekniikan korkeakoulu; Seppänen, JanneIn the Nordic power system, ultra-low frequency oscillations (ULFO) cause the system frequency to oscillate around the nominal value of 50 Hz, usually with an amplitude of 20–40 mHz and a time period of 40–90 seconds. They occur primarily due to the significant presence of hydropower. During an ULFO phenomenon, synchronous generators oscillate coherently. The water hammer effect and the quick operation of the hydraulic governors reduce the damping of oscillations. ULFOs lead to unnecessary changes in governors’ setpoints and wear and tear of electrical equipment. ULFOs are characterised by frequency, amplitude and damping ratio. This thesis looks into ULFOs in the Nordic power system and how they depend on various power system variables – inertia, electricity production, electricity consumption, hydroelectricity production, wind power production and transfer of electricity between Finland and neighbouring countries. To carry out the analyses, modal analysis with multivariate autoregressive (MAR) method is used to estimate the frequency, amplitude and damping ratio of ULFOs. The correlation coefficients between these parameters of ULFOs and power system variables are then calculated. According to the results, the frequency and amplitude of ULFOs are higher during the summers and lower during the winters. In the recent years, the ULFO amplitude has increased, while its damping has decreased. During summers, the electricity supply and demand as well as the power system inertia is low. High inertia during winters, when production and consumption of electricity is high, stabilizes the power system. The power system inertia has decreased over the past few years, but the inertia varies. ULFOs show high negative correlation with inertia, electricity production and consumption – when one parameter increases the other decreases and vice versa. Hydroelectricity produced in Norway has a higher influence on ULFOs, compared to Sweden and Finland. Wind power integration reduces system inertia. Wind power, however, does not have a clear impact on ULFOs. On a similar note, the import or export of electricity to or from Finland does not affect ULFOs. The correlations calculated by using the daily averages of the power system variables are stronger than the correlations obtained by using the hourly averages.