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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Détection d'évènements simples à partir de mesures sur courant alternatif / Detection of simple events from alternative current measurements

Amirach, Nabil 10 June 2015 (has links)
La nécessité d’économiser de l'énergie est l’un des axes importants de ces dernières décennies, d’où le besoin de surveiller la consommation d'énergie des processus résidentiels et industriels. Le travail de recherche présenté dans ce manuscrit s’inscrit plus particulièrement dans le suivi de la consommation électrique afin de permettre l’économie d’énergie. Le but final étant d'avoir une connaissance précise et fiable d'un réseau électrique donné. Cela passe par la décomposition de la consommation électrique globale du réseau électrique étudié afin de fournir une analyse détaillée de l'énergie consommée par usage. L’objectif de cette thèse est la mise en place d’une approche non-intrusive permettant de réaliser les étapes de détection d’évènements et d’extraction de caractéristiques, qui précédent les étapes de classification et d’estimation de la consommation électrique par usage. L’algorithme résultant des travaux effectués durant cette thèse permet de détecter les évènements qui surviennent sur le courant et d’y associer un vecteur d’information contenant des paramètres caractérisant le régime permanent et le régime transitoire. Ce vecteur d’information permet ensuite de reconnaître tous les évènements liés à la même charge électrique. / The need to save energy is an important focus of recent decades, hence the need to monitor the energy consumption of residential and industrial processes. The research works presented in this manuscript are within the monitoring power consumption area in order to enable energy saving. The final goal is to have a clear and reliable knowledge of a given grid. This involves the decomposition of the overall power consumption of the electrical network to provide a detailed analysis of the consumed energy. The objective of this thesis is to develop a non-intrusive approach to achieve the event detection and feature extraction steps, which precede the classification and the power consumption estimation steps. The algorithm resulting from the works performed in this thesis can detect events which occur on the current and associates to them an information vector containing the parameters characterizing the steady and transient states. Then this information vector is used to recognize all the events linked to the same electrical load.
2

An advanced non-intrusive load monitoring technique and its application in smart grid building energy management systems

He, Dawei 27 May 2016 (has links)
The objective of the proposed research is to develop an intelligent load modeling, identification, and prediction technology to provide granular load energy consumption and performance details and drive building energy reduction, demand reduction, and proactive equipment maintenance. Electricity consumption in commercial and residential sectors accounts for about 70% of the total electricity generation in United States. Buildings are the most important consumers, and contribute to over 80% of the consumptions in these two sectors. To reduce electrical energy spending and carbon emission, several studies from Pacific Northwest National Lab (PNNL) and National Renewable Energy Lab (NREL) prove that if equipped with the proper technologies, a commercial or a residential building can potentially improve energy savings of buildings by up to about 10% to 30% of their usage. However, the market acceptance of these new technologies today is still not sufficient, and the reason is generally acknowledged to be the lack of solution to quantify the contributions of these new technologies to the energy savings, and the invisibility of the loads in buildings. A non-intrusive load monitoring (NILM) system is proposed in this dissertation, which can identify every individual load in buildings and record the energy consumption, time-of-day variations and other relevant statistics of the identified load, with no access to the individual component. The challenge of such a non-intrusive load monitoring is to find features that are unique for a particular load and then to match a measured feature of an unknown load against a database or library of known. Many problems exist in this procedure and the proposed research is going to focus on three directions to overcome the bottlenecks. They are respectively fundamental load studies for a model-driven feature extraction, adaptive identification algorithms for load space extendibility, and the practical simplifications for the real industrial applications. The simulation results show the great potentials of this new technology in building energy monitoring and management.
3

Non-Intrusive Load Monitoring to Assess Retrofitting Work / Non-intrusive load monitoring för utvärderingen av renoveringsarbetens effektiviteten

Zucchet, Julien January 2022 (has links)
Non-intrusive load monitoring (NILM) refers to a set of statistical methods for inferring information about a household from its electricity load curve, without adding any additional sensor. The aim of this master thesis is to adapt NILM techniques for the assessment of the efficiency of retrofitting work to provide a first version of a retrofitting assessment tool. Two models are developed: a model corresponding to a constrained optimization problem, and a hierarchical Bayesian mixture model. These models are tested on a set of houses that have electric heating (which are the main target of retrofitting work). These models offer a satisfactory accuracy retrofitting assessment for about half of the houses. / Non-intrusive load monitoring (NILM) består av en uppsättning statistiska metoder för att härleda information om ett hushåll från belastningskurvan i bostaden, utan att lägga till ytterligare sensorer. Syftet med detta examensarbete är att anpassa NILM-teknikerna till utvärdering av energieffektivitet i energibyggnader och för att föreslå en första version av ett verktyg för utvärdering av effektiviteten i renoveringsarbeten. Två modeller föreslås: en modell som motsvarar ett begränsat optimeringsproblem och en hierarkisk Bayesiansk blandningsmodell. Modellerna testas på en uppsättning med elvärme (som är huvudmålet för renoveringsarbeten). De utvecklade modellerna gör det möjligt att upprå en tillfredsställande noggrannhet vid utvärderingen av arbeten för ungefär hälften av husen.
4

A Framework for Estimating Energy Consumed by Electric Loads Through Minimally Intrusive Approaches

Giri, Suman 01 April 2015 (has links)
This dissertation explores the problem of energy estimation in supervised Non-Intrusive Load Monitoring (NILM). NILM refers to a set of techniques used to estimate the electricity consumed by individual loads in a building from measurements of the total electrical consumption. Most commonly, NILM works by first attributing any significant change in the total power consumption (also known as an event) to a specific load and subsequently using these attributions (i.e. the labels for the events) to estimate energy for each load. For this last step, most proposed solutions in the field impart simplifying assumptions to make the problem more tractable. This has severely limited the practicality of the proposed solutions. To address this knowledge gap, we present a framework for creating appliance models based on classification labels and aggregate power measurements that can help relax many of these assumptions. Within the framework, we model the problem of utilizing a sequence of event labels to generate energy estimates as a broader class of problems that has two major components (i) With the understanding that the labels arise from a process with distinct states and state transitions, we estimate the underlying Finite State Machine (FSM) model that most likely generated the observed sequence (ii) We allow for the observed sequence to have errors, and present an error correction algorithm to detect and correct them. We test the framework on data from 43 appliances collected from 19 houses and find that it improves errors in energy estimates when compared to the case with no correction in 19 appliances by a factor of 50, leaves 17 appliances unchanged, and negatively impacts 6 appliances by a factor of 1.4. This approach of utilizing event sequences to estimate energy has implications in virtual metering of appliances as well. In a case study, we utilize this framework in order to substitute the need of plug-level sensors with cheap and easily deployable contacless sensors, and find that on the 6 appliances virtually metered using magnetic field sensors, the inferred energy values have an average error of 10:9%.
5

NON-INTRUSIVE LOAD EXTRACTION OF ELECTRIC VEHICLE CHARGING LOADS FOR EDGE COMPUTING

Hyeonae Jang (8790983) 01 May 2020 (has links)
<div>The accelerated urbanization of countries has led the adoption of the smart power grid with an explosion in high power usage. The emergence of Non-intrusive load monitoring (NILM), also referred to as Energy Disaggregation has followed the recent worldwide adoption of smart meters in smart grids. NILM is a convenient process to analyze composite electrical energy load and determine electrical energy consumption.</div><div><br></div><div>A number of state-of-the-art NILM (energy disaggregation) algorithms have been proposed recently to detect various individual appliances from one aggregated signal observation. Different kinds of classification methods such as Hidden Markov Model (HMM), Support Vector Method (SVM), neural networks, fuzzy logic, Naive Bayes, k-Nearest Neighbors (kNN), and many other hybrid approaches have been used to classify the estimated power consumption of electrical appliances from extracted appliances signatures. This study proposes an end-to-end edge computing system with an NILM algorithm, which especially focuses on recognizing Electric Vehicle (EV) charging. This system consists of three main components: (1) Data acquisition and Preprocessing, (2) Extraction of EV charging load via an NILM algorithm (Load identification) on the NILMTK Framework, (3) and Result report to the cloud server platform.</div><div><br></div><div>The monitoring of energy consumption through the proposed system is remarkably beneficial for demand response and energy efficiency. It helps to improve the understanding and prediction of power grid stress as well as enhance grid system reliability and resilience of the power grid. Furthermore, it is highly advantageous for the integration of more renewable energies that are under rapid development. As a result, countless potential NILM use-cases are expected from monitoring and identifying energy consumption in a power grid. It would enable smarter power consumption plans for residents as well as more flexible power grid management for electric utility companies, such as Duke Energy and ComEd.</div>
6

Source Code

Hyeonae Jang (8790983) 01 May 2020 (has links)
This compressed file consists of h5 and python files created to conduct the thesis study
7

An approach to evaluate machine learning algorithms for appliance classification

Olsson, Charlie, Hurtig, David January 2019 (has links)
A cheap and powerful solution to lower the electricity usage and making the residents more energy aware in a home is to simply make the residents aware of what appliances that are consuming electricity. Meaning the residents can then take decisions to turn them off in order to save energy. Non-intrusive load monitoring (NILM) is a cost-effective solution to identify different appliances based on their unique load signatures by only measuring the energy consumption at a single sensing point. In this thesis, a low-cost hardware platform is developed with the help of an Arduino to collect consumption signatures in real time, with the help of a single CT-sensor. Three different algorithms and one recurrent neural network are implemented with Python to find out which of them is the most suited for this kind of work. The tested algorithms are k-Nearest Neighbors, Random Forest and Decision Tree Classifier and the recurrent neural network is Long short-term memory.
8

Hybrid Model Approach to Appliance Load Disaggregation : Expressive appliance modelling by combining convolutional neural networks and hidden semi Markov models. / Hybridmodell för disaggregering av hemelektronik : Detaljerad modellering av elapparater genom att kombinera neurala nätverk och Markovmodeller.

Huss, Anders January 2015 (has links)
The increasing energy consumption is one of the greatest environmental challenges of our time. Residential buildings account for a considerable part of the total electricity consumption and is further a sector that is shown to have large savings potential. Non Intrusive Load Monitoring (NILM), i.e. the deduction of the electricity consumption of individual home appliances from the total electricity consumption of a household, is a compelling approach to deliver appliance specific consumption feedback to consumers. This enables informed choices and can promote sustainable and cost saving actions. To achieve this, accurate and reliable appliance load disaggregation algorithms must be developed. This Master's thesis proposes a novel approach to tackle the disaggregation problem inspired by state of the art algorithms in the field of speech recognition. Previous approaches, for sampling frequencies <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cleq" />1 Hz, have primarily focused on different types of hidden Markov models (HMMs) and occasionally the use of artificial neural networks (ANNs). HMMs are a natural representation of electric appliances, however with a purely generative approach to disaggregation, basically all appliances have to be modelled simultaneously. Due to the large number of possible appliances and variations between households, this is a major challenge. It imposes strong restrictions on the complexity, and thus the expressiveness, of the respective appliance model to make inference algorithms feasible. In this thesis, disaggregation is treated as a factorisation problem where the respective appliance signal has to be extracted from its background. A hybrid model is proposed, where a convolutional neural network (CNN) extracts features that correlate with the state of a single appliance and the features are used as observations for a hidden semi Markov model (HSMM) of the appliance. Since this allows for modelling of a single appliance, it becomes computationally feasible to use a more expressive Markov model. As proof of concept, the hybrid model is evaluated on 238 days of 1 Hz power data, collected from six households, to predict the power usage of the households' washing machine. The hybrid model is shown to perform considerably better than a CNN alone and it is further demonstrated how a significant increase in performance is achieved by including transitional features in the HSMM. / Den ökande energikonsumtionen är en stor utmaning för en hållbar utveckling. Bostäder står för en stor del av vår totala elförbrukning och är en sektor där det påvisats stor potential för besparingar. Non Intrusive Load Monitoring (NILM), dvs. härledning av hushållsapparaters individuella elförbrukning utifrån ett hushålls totala elförbrukning, är en tilltalande metod för att fortlöpande ge detaljerad information om elförbrukningen till hushåll. Detta utgör ett underlag för medvetna beslut och kan bidraga med incitament för hushåll att minska sin miljöpåverakan och sina elkostnader. För att åstadkomma detta måste precisa och tillförlitliga algoritmer för el-disaggregering utvecklas. Denna masteruppsats föreslår ett nytt angreppssätt till el-disaggregeringsproblemet, inspirerat av ledande metoder inom taligenkänning. Tidigare angreppsätt inom NILM (i frekvensområdet <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cleq" />1 Hz) har huvudsakligen fokuserat på olika typer av Markovmodeller (HMM) och enstaka förekomster av artificiella neurala nätverk. En HMM är en naturlig representation av en elapparat, men med uteslutande generativ modellering måste alla apparater modelleras samtidigt. Det stora antalet möjliga apparater och den stora variationen i sammansättningen av dessa mellan olika hushåll utgör en stor utmaning för sådana metoder. Det medför en stark begränsning av komplexiteten och detaljnivån i modellen av respektive apparat, för att de algoritmer som används vid prediktion ska vara beräkningsmässigt möjliga. I denna uppsats behandlas el-disaggregering som ett faktoriseringsproblem, där respektive apparat ska separeras från bakgrunden av andra apparater. För att göra detta föreslås en hybridmodell där ett neuralt nätverk extraherar information som korrelerar med sannolikheten för att den avsedda apparaten är i olika tillstånd. Denna information används som obervationssekvens för en semi-Markovmodell (HSMM). Då detta utförs för en enskild apparat blir det beräkningsmässigt möjligt att använda en mer detaljerad modell av apparaten. Den föreslagna Hybridmodellen utvärderas för uppgiften att avgöra när tvättmaskinen används för totalt 238 dagar av elförbrukningsmätningar från sex olika hushåll. Hybridmodellen presterar betydligt bättre än enbart ett neuralt nätverk, vidare påvisas att prestandan förbättras ytterligare genom att introducera tillstånds-övergång-observationer i HSMM:en.
9

Identification d’appareils électriques par analyse des courants de mise en marche / Analysis of turn-on transient currents for electrical appliances identification

Nait Meziane, Mohamed 09 December 2016 (has links)
Le domaine lié à ce travail est appelé « désagrégation d’énergie », où la principale préoccupation est de décomposer, ou désagréger, la consommation globale d’énergie électrique (par exemple, la consommation de tout un ménage) en une consommation détaillée donnée comme information de consommation par usage (par exemple, par appareil). Cette dernière permet d’avoir un retour sur la consommation pour les consommateurs ainsi que pour les fournisseurs et est utile pour permettre des économies d’énergie. Dans ce domaine de désagrégation d’énergie, il existe trois grandes questions auxquelles il faut répondre : qui consomme ? quand ? et combien ? Les recherches menées dans cette thèse se concentrent sur l’identification des appareils électriques, c’est-à-dire la réponse à la première question, en considérant particulièrement des appareils ménagers. À cet effet, nous utilisons le courant transitoire de mise en marche que nous modélisons en utilisant un nouveau modèle que nous avons proposé. De plus, nous utilisons les paramètres estimés de ce dernier pour la tâche d’identification. / The related field to this work is called “energy disaggregation" where the main concern is to break down, or disaggregate, the global electrical energy consumption (e.g. wholehouse consumption) into a detailed consumption given as end-use (e.g. appliance-level) consumption information. This latter gives consumption feedback to consumers and electricity providers and is helpful for energy savings. Three main questions have to be answered in the energy disaggregation field : who is consuming ? when ? and how much ? The research conducted in this thesis focuses on electrical appliances identification, i.e. the who question, considering particularly home appliances. For this purpose, we use the turn-on transient current signal which we model using a new model we proposed and use its estimated model parameters for the identification task.
10

Rede neural convolucional aplicada à identificação de equipamentos residenciais para sistemas de monitoramento não-intrusivo de carga / Convolutional neural network applied to the identification of residential equipment for non-intrusive load monitoring systems

PENHA, Deyvison de Paiva 03 April 2018 (has links)
Submitted by Kelren Mota (kelrenlima@ufpa.br) on 2018-06-25T18:48:12Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_RedeNeuralConvolucional.pdf: 2088560 bytes, checksum: 6328f6f59bc552055a366b1e4a32793d (MD5) / Approved for entry into archive by Kelren Mota (kelrenlima@ufpa.br) on 2018-06-25T18:48:32Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_RedeNeuralConvolucional.pdf: 2088560 bytes, checksum: 6328f6f59bc552055a366b1e4a32793d (MD5) / Made available in DSpace on 2018-06-25T18:48:32Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_RedeNeuralConvolucional.pdf: 2088560 bytes, checksum: 6328f6f59bc552055a366b1e4a32793d (MD5) Previous issue date: 2018-04-03 / Este trabalho apresenta a proposta de uma nova metodologia para identificação de equipamentos residenciais em sistemas de Monitoramento Não-Intrusivo de cargas. O sistema é baseado em uma Rede Neural Convolucional para classificação dos equipamentos, que utilizam, diretamente como entradas para o sistema, os dados do sinal transitório de potência de 7 equipamentos obtidos no momento em que estes são ligados em uma residência. A metodologia foi desenvolvida usando dados de um banco de dados público (REED) que apresenta dados coletados a uma baixa frequência (1 Hz). Os resultados obtidos na base de dados de testes apresentam acurácia superior a 90%, indicando que o sistema proposto é capaz de realizar a tarefa de identificação, além disso os resultados apresentados são considerados satisfatórios quando comparados com os resultados já apresentados na literatura para o problema em questão. / This research presents the proposal of a new methodology for the identification of residential equipment in non-intrusive load monitoring systems. The system is based on a Convolutional Neural Network to classify residential equipment, which uses directly as inputs to the system, the transient power signal data of 7 equipment obtained at the moment they are connected in a residence. The methodology was developed using data from a public database (REED) that presents data collected at a low frequency (1 Hz). The results obtained in the test database show an accuracy of more than 90%, indicating that the proposed system is capable of performing the task of identification. In addition, the results presented are considered satisfactory when compared with the results already presented in the literature for the problem in question.

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