Sökning: "partial discharges"

Visar resultat 1 - 5 av 16 uppsatser innehållade orden partial discharges.

  1. 1. Monitoring of Partial Discharges on Cable Terminations : An experimental approach to evaluate non-conventional online PD measurement techniques

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Tony Sibo; [2023]
    Nyckelord :Monitoring; Partial discharges; Medium-voltage cable terminations; Sensor performance; Reliability evaluation; Infrared camera IR-camera ; Ultrasonic emission sensor AE-sensor ; Temperature and relative humidity sensor TRH-sensor ; High frequency current transformer HFCT ; Transient earth voltage antenna TEV-antenna ; Conventional VS non-conventional PD measurement techniques; Övervakning; Partiella urladdningar; Mellanspänningskabelslut; Evaluering av sensorprestanda; Utvärdering av systemets tillförlitlighet; Infraröd kamera; Ultraljudssensor; Temperatur- och relativ fuktighetssensor; Högfrekvent strömtransformator; Transient jordspänningsantenn; Konventionella vs icke-konventionella mättekniker;

    Sammanfattning : The transmission of electric power over long distances has historically posed challenges. However, the advent of high-voltage engineering has not only addressed distance barriers and power losses in electricity transmission and distribution, but it has also significantly improved the efficiency and transmission capacity of power grids. LÄS MER

  3. 2. Unsupervised Detection of Interictal Epileptiform Discharges in Routine Scalp EEG : Machine Learning Assisted Epilepsy Diagnosis

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Avdelningen Vi3

    Författare :Shuai Shao; [2023]
    Nyckelord :EEG; electroencephalography; IED; interictal epileptiform discharges; spike detection; epilepsy; unsupervised; Fourier transform; STFT; short-time Fourier transform; CWT; continuous wavelet transform; DWT; discrete wavelet transform; ML; machine learning; ANN; artificial neural network; CNN; convolutional neural network; autoencoder; HMM; hidden Markov model; ECS; Euclidean distance of cumulative spectrum;

    Sammanfattning : Epilepsy affects more than 50 million people and is one of the most prevalent neurological disorders and has a high impact on the quality of life of those suffering from it. However, 70% of epilepsy patients can live seizure free with proper diagnosis and treatment. Patients are evaluated using scalp EEG recordings which is cheap and non-invasive. LÄS MER

  4. 3. Predicting Top-Oil-Temperature in Power Transformers with Light Gradient Boosting Machine

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Victor Löfgren; [2022]
    Nyckelord :;

    Sammanfattning : Online monitoring of mineral-oil-immersed transformer variables provide capabilities such as failure avoidance, optimization of load capacity and maintenance as well as extending the remaining life expectancy. A central role is played by the Top-Oil-Temperature which in its own is an indicator of harmful events or transformer states. LÄS MER

  5. 4. Insulation diagnostics of stator bars

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Alexandra Garðarsdóttir; [2022]
    Nyckelord :Electrical insulation system; Stator bars; Insulation testing; Rotating machines; Partial discharges; Acoustic detection; Dielectric response analysis; Break-down test; Tap test; Elektriskt isoleringssystem; Statorstavar; Isolationsprovning; Roterande maskiner; Partiell urladdning; Akustisk detektering; Dielektrisk responsanalys; Nedbrytningstest; Taptest;

    Sammanfattning : Insulation in rotating machines is a common cause for failure. Therefore, research in the area is large and is important to further increase the knowledge of the phenomena related to insulation degradation. LÄS MER

  7. 5. Measurements of partial discharge in insulators

    Kandidat-uppsats,

    Författare :Elias Johansson; Didrik Olofsson; Philip Lind; Erik Victorin; [2019]
    Nyckelord :Partial discharge; Substations; PDS100;

    Sammanfattning : Causes and effects of partial discharges (PD) inside electrical high-voltage insulation was studied prior to taking measurements with a PDS100 spectralanalyser during excursions to a number of substations in the Swedish electrical grid.This to develop a working-method and manual for workers to use periodically whileon site to be able to identify components on which maintenance is needed. LÄS MER