12,153 research outputs found
NILM techniques for intelligent home energy management and ambient assisted living: a review
The ongoing deployment of smart meters and different commercial devices has made electricity disaggregation feasible in buildings and households, based on a single measure of the current and, sometimes, of the voltage. Energy disaggregation is intended to separate the total power consumption into specific appliance loads, which can be achieved by applying Non-Intrusive Load Monitoring (NILM) techniques with a minimum invasion of privacy. NILM techniques are becoming more and more widespread in recent years, as a consequence of the interest companies and consumers have in efficient energy consumption and management. This work presents a detailed review of NILM methods, focusing particularly on recent proposals and their applications, particularly in the areas of Home Energy Management Systems (HEMS) and Ambient Assisted Living (AAL), where the ability to determine the on/off status of certain devices can provide key information for making further decisions. As well as complementing previous reviews on the NILM field and providing a discussion of the applications of NILM in HEMS and AAL, this paper provides guidelines for future research in these topics.AgĂȘncia financiadora:
Programa Operacional Portugal 2020 and Programa Operacional Regional do Algarve
01/SAICT/2018/39578
Fundação para a CiĂȘncia e Tecnologia through IDMEC, under LAETA:
SFRH/BSAB/142998/2018
SFRH/BSAB/142997/2018
UID/EMS/50022/2019
Junta de Comunidades de Castilla-La-Mancha, Spain:
SBPLY/17/180501/000392
Spanish Ministry of Economy, Industry and Competitiveness (SOC-PLC project):
TEC2015-64835-C3-2-R MINECO/FEDERinfo:eu-repo/semantics/publishedVersio
Scenarios for the development of smart grids in the UK: literature review
Smart grids are expected to play a central role in any transition to a low-carbon energy future, and much research is currently underway on practically every area of smart grids. However, it is evident that even basic aspects such as theoretical and operational definitions, are yet to be agreed upon and be clearly defined. Some aspects (efficient management of supply, including intermittent supply, two-way communication between the producer and user of electricity, use of IT technology to respond to and manage demand, and ensuring safe and secure electricity distribution) are more commonly accepted than others (such as smart meters) in defining what comprises a smart grid.
It is clear that smart grid developments enjoy political and financial support both at UK and EU levels, and from the majority of related industries. The reasons for this vary and include the hope that smart grids will facilitate the achievement of carbon reduction targets, create new employment opportunities, and reduce costs relevant to energy generation (fewer power stations) and distribution (fewer losses and better stability). However, smart grid development depends on additional factors, beyond the energy industry. These relate to issues of public acceptability of relevant technologies and associated risks (e.g. data safety, privacy, cyber security), pricing, competition, and regulation; implying the involvement of a wide range of players such as the industry, regulators and consumers.
The above constitute a complex set of variables and actors, and interactions between them. In order to best explore ways of possible deployment of smart grids, the use of scenarios is most adequate, as they can incorporate several parameters and variables into a coherent storyline. Scenarios have been previously used in the context of smart grids, but have traditionally focused on factors such as economic growth or policy evolution. Important additional socio-technical aspects of smart grids emerge from the literature review in this report and therefore need to be incorporated in our scenarios. These can be grouped into four (interlinked) main categories: supply side aspects, demand side aspects, policy and regulation, and technical aspects.
Analysis of the dynamic performance of self-excited induction generators employed in renewable energy generation
Incentives, such as the Feed-in-tariff are expected to lead to continuous increase in the deployment of Small Scale Embedded Generation (SSEG) in the distribution network. Self-Excited Induction Generators (SEIG) represent a significant segment of potential SSEG. The quality of SEIG output voltage magnitude and frequency is investigated in this paper to support the SEIG operation for different network operating conditions. The dynamic behaviour of the SEIG resulting from disconnection, reconnection from/to the grid and potential operation in islanding mode is studied in detail. The local load and reactive power supply are the key factors that determine the SEIG performance, as they have significant influence on the voltage and frequency change after disconnection from the grid. Hence, the aim of this work is to identify the optimum combination of the reactive power supply (essential for self excitation of the SEIG) and the active load (essential for balancing power generation and demand). This is required in order to support the SEIG operation after disconnection from the grid, during islanding and reconnection to the grid. The results show that the generator voltage and speed (frequency) can be controlled and maintained within the statuary limits. This will enable safe disconnection and reconnection of the SEIG from/to the grid and makes it easier to operate in islanding mode
Ancillary Services in Hybrid AC/DC Low Voltage Distribution Networks
In the last decade, distribution systems are experiencing a drastic transformation
with the advent of new technologies. In fact, distribution networks are no longer passive
systems, considering the current integration rates of new agents such as distributed generation,
electrical vehicles and energy storage, which are greatly influencing the way these systems are
operated. In addition, the intrinsic DC nature of these components, interfaced to the AC system
through power electronics converters, is unlocking the possibility for new distribution topologies
based on AC/DC networks. This paper analyzes the evolution of AC distribution systems,
the advantages of AC/DC hybrid arrangements and the active role that the new distributed agents
may play in the upcoming decarbonized paradigm by providing different ancillary services.Ministerio de EconomĂa y Competitividad ENE2017-84813-RUniĂłn Europea (Programa Horizonte 2020) 76409
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Privacy In The Smart Grid: An Information Flow Analysis
Project Final Report prepared for CIEE and California Energy Commissio
Investigation into the impact of wind power generation on demand side management (DSM) practices
The construction of a number of wind farms in South Africa will lay the foundation for the
country to embrace the generation of greener energy into the National Grid. Despite the
benefits derived from introducing wind power generation into the grid, this source
encompasses adverse effects which need to be managed. These adverse effects include the
intermittency and lack of predictability of wind. In power systems with a high penetration of
wind energy, these effects can severely affect the power systemâs security and reliability in
the event of significant rapid ramp rates. Recently, many utilities around the world have been
exploring the use of Demand Side Management (DSM) and Demand Response (DR)
initiatives and programmes to support and manage the intermittency of wind power
generation.
This report outlines the programmes and benefits of DSM/DR and provides a critical analysis
of the challenges facing South Africa with implementing these initiatives. Introducing these
programmes necessitates the employment of a number of Smart Grid technologies including
Advanced Metering Infrastructure (AMI), next generation telecommunications technologies,
smart meters, enterprise system integration and dynamic pricing. These tools and techniques
are discussed and their challenges described within the context of South Africaâs current state
of the power system. The current practices for DSM/DR in South Africa have been evaluated
in this report. Despite, the success of many DSM/DR initiatives in the commercial, industrial
and agricultural sectors, it is found that much work is still required in the residential sectors
as the current DSM initiatives are not adequate for managing wind power generation. A
detailed analysis and recommendations for South Africaâs DR program is then presented
based on industry best practices and experiences from other utilities who are currently
exploring DSM/DR in the residential sector using Smart Grid technologies
Fast and Reliable Primary Frequency Reserves From Refrigerators with Decentralized Stochastic Control
Due to increasing shares of renewable energy sources, more frequency reserves
are required to maintain power system stability. In this paper, we present a
decentralized control scheme that allows a large aggregation of refrigerators
to provide Primary Frequency Control (PFC) reserves to the grid based on local
frequency measurements and without communication.
The control is based on stochastic switching of refrigerators depending on
the frequency deviation. We develop methods to account for typical lockout
constraints of compressors and increased power consumption during the startup
phase. In addition, we propose a procedure to dynamically reset the thermostat
temperature limits in order to provide reliable PFC reserves, as well as a
corrective temperature feedback loop to build robustness to biased frequency
deviations. Furthermore, we introduce an additional randomization layer in the
controller to account for thermostat resolution limitations, and finally, we
modify the control design to account for refrigerator door openings.
Extensive simulations with actual frequency signal data and with different
aggregation sizes, load characteristics, and control parameters, demonstrate
that the proposed controller outperforms a relevant state-of-the-art
controller.Comment: 44 pages, 17 figures, 9 Tables, submitted to IEEE Transactions on
Power System
Supporting transient stability in future highly distributed power systems
Incorporating a substantial volume of microgeneration (consumer-led rather than centrally planed) within a system that is not designed for such a paradigm could lead to conflicts in the operating strategies of the new and existing centralised generation technologies. So it becomes vital for such substantial amounts of microgeneration among other decentralised resources to be controlled in the way that the aggregated response will support the wider system. In addition, the characteristic behaviour of such populations requires to be understood under different system conditions to ascertain measures of risk and resilience. Therefore, this paper provides two main contributions: firstly, conceptual control for a system incorporating a high penetration of microgeneration and dynamic load, termed a Highly Distributed Power System (HDPS), is proposed. Secondly, a technical solution that can support enhanced transient stability in such a system is evaluated and demonstrated
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