Design of an Energy Management System for Secure Integration of Renewable Energy Sources into Microgrids

This chapter presents the design and development of an energy management system (EMS), which guarantees a secure operation of an islanded microgrid under possible imbalances between generation capacity and loads demand. The EMS performs an optimal calculation of low priority loads to be shed, as well as charging and discharging cycles of batteries within the microgrid. A nonlinear model‐predictive control (NMPC) algorithm is selected for implementing the EMS, which processes a data set composed of loads measurements, generation capacity, batteries state of charge (SOC), and a set of operation constraints. The EMS is designed under the assumption of having an advanced metering infrastructure (AMI) installed in the microgrid. The EMS is tested in a simulation platform that integrates models of the microgrid components, as well as their distributed controllers (DCs). Simulation results show the effectiveness of the proposed approach, since critical variables as the microgrid’s frequency and voltage magnitude operate within a secured interval even under the presence of faults in one of the DCs

Robust multi-objective control of hybrid renewable microgeneration systems with energy storage

Microgeneration technologies are positioned to address future building energy efficiency requirements and facilitate the integration of renewables into buildings to ensure a sustainable, energy-secure future. This paper explores the development of a robust multi-input multi-output (MIMO) controller applicable to the control of hybrid renewable microgeneration systems with the objective of minimising the electrical grid utilisation of a building while fulfilling the thermal demands. The controller employs the inverse dynamics of the building, servicing systems, and energy storage with a robust control methodology. These inverse dynamics provides the control system with knowledge of the complex cause and effect relationships between the system, the controlled inputs, and the external disturbances, while an outer-loop control ensures robust, stable control in the presence of modelling deficiencies/uncertainty and unknown disturbances. Variable structure control compensates for the physical limitations of the systems whereby the control strategy employed switches depending on the current utilisation and availability of the energy supplies. Preliminary results presented for a system consisting of a micro-CHP unit, solar PV, and battery storage indicate that the control strategy is effective in minimising the interaction with the local electrical network and maximising the utilisation of the available renewable energy

IoT-teknologian hyödyntäminen sähköverkko-omaisuuden hallinnassa

Objective of this thesis is to define and assess changes in energy sector, which will directly or indirectly affect distribution grid operation and management in Finland, and to determine measurable events or variables, which enable identification and monitoring of the recognized changes. Based on assessment of the upcoming changes, possibilities for utilizing IoT technologies in management and monitoring applications of the identified changes, are assessed. In the assessment of upcoming changes, total of eight subjects were covered and microgeneration, electric vehicles and heat pumps were identified to be the most probable changes to realistically penetrate Finnish energy sector within a time scope of approximately 10 years. However, none of the assessed, changes, were found to have significant and wide-scale effects in terms of performance of Finnish distribution networks. For utilization of IoT technologies in distribution networks one application for operational grid monitoring of power quality problems derived from residential photovoltaic generation, and three cases for IoT based asset health and condition monitoring were assessed. Furthermore, requirements and architecture for data storage and analysis platform of IoT based system were discussed. From the evaluated applications condition monitoring scheme of circuit breakers was determined to be the most promising alternative.Diplomityön tavoitteena on määritellä ja arvioida energiasektoriin vaikuttavien tulevien muutosten suoria tai epäsuoria vaikutuksia jakeluverkon toimintaan ja hallintaan. Havaittujen muutosten vaikutuksista on tarkoitus tunnistaa mitattavia ilmiöitä tai suureita, jotka mahdollistavat muutosten tunnistamisen sekä seurannan. Muutosanalyysiin pohjautuen tavoitteena on tunnistaa ja arvioida mahdollisuuksia IoT-teknologian hyödyntämiseksi havaittujen muutosten aiheuttamien ongelmakohtien tai mahdollisuuksien tunnistamisessa, seurannassa sekä hallinnassa. Energiasektoriin vaikuttavien muutosten analyysissä arvoitiin kokonaisuudessaan kahdeksaa eri aihealuetta ja lopputuloksena pientuotannon, sähköautojen sekä lämpöpumppujen todettiin olevan todennäköisimmät teknologiat, jotka yleistyvät merkittävissä määrin suomalaisessa sähköverkossa seuraavan kymmenen vuoden aikana. Minkään käsitellyn muutoskohdan ei kuitenkaan todettu aiheuttavan laajamittaisia ja merkittäviä ongelmia jakeluverkon toimintaan. IoT-teknologian hyödyntämiseen jakeluverkkotoiminnassa käsiteltiin yhtä verkon käyttöön ja sähkön laatuun liittyvää sovellusta, jonka avulla hajautetun pienaurinkotuotannon vaikutuksia pystytään seuraamaan, sekä lisäksi kolmeen eri verkkokomponenttiin kohdistuvaa jatkuvan kunnon seurannan sovellusta. Tämän lisäksi IoT-järjestelmän toteuttamiseksi vaadittavalle analyysi- ja tietojärjestelmäalustalle määriteltiin rakenteellisia ja toiminnallisia tarpeita. Työssä käsitellyistä IoT-sovelluksista lupaavimmaksi todettiin katkaisijoihin kohdistuva jatkuvan kunnonhallinnan sovellus

Power Electronics Applications in Renewable Energy Systems

The renewable generation system is currently experiencing rapid growth in various power grids. The stability and dynamic response issues of power grids are receiving attention due to the increase in power electronics-based renewable energy. The main focus of this Special Issue is to provide solutions for power system planning and operation. Power electronics-based devices can offer new ancillary services to several industrial sectors. In order to fully include the capability of power conversion systems in the network integration of renewable generators, several studies should be carried out, including detailed studies of switching circuits, and comprehensive operating strategies for numerous devices, consisting of large-scale renewable generation clusters

Economic-efficient design of residential net zero energy buildings with respect to local context

Tese de doutoramento. Sistemas Sustentáveis de Energia. Faculdade de Engenharia. Universidade do Porto. 201

A novel energy management system for optimal energy and flexibility scheduling of residential buildings: a case study in HSB Living Lab

The future distribution system needs more flexibility to handle the peak power demand arising from the electrification of heating and transportation. This paper proposes a novel energy management system (EMS) for residential buildings to optimize their electric and heat consumptions while offering flexibility in response to the requirements of the Distribution System Operator (DSO). The aim of the proposed EMS is to minimize the energy and peak power costs while simultaneously maximizing the revenue from offering flexibility. This is achieved through the optimal scheduling of battery energy storage charging and discharging as well as the efficient utilization of the heat pump. To cope with forecasting uncertainties, a rolling horizon-based algorithm with uncertainty modelling based on the chance constraint method is incorporated. The performance of the proposed EMS is investigated by simulating the daily operation of a real residential building. The case studies indicate that the scheduled flexibility can be successfully dispatched even in the presence of forecasting uncertainties, causing 6% reduction in the payment cost of the building

A Compressive Receding Horizon Approach for Smart Home Energy Management

UID/CEC/00326/2020Current increases in the demand for electricity require sustainable energy management measures and have promoted the adoption of clean and renewable sources, particularly at the residential building level. Active demand management is usually carried out through load shifting based on specific techniques, such as optimisation, heuristics, model-based predictive control and machine learning methodologies. This work addresses the problem of residential load scheduling via optimisation techniques. A compressive receding horizon strategy is proposed for week-ahead load shifting, and the selection is driven by traditional receding horizon and day-ahead allocation strategy misalignment, with weekly household appliance usage patterns. The proposed approach is compared with receding horizon and day-ahead scheduling techniques over 30 different weeks for a prototypical smart home with non-controllable demand, which is representative of a four-resident family and includes micro power generation and battery storage. The simulation results confirm the validity of the proposed strategy in the context of household appliance scheduling problems and show competitive electricity costs and resident discomfort performance compared to state-of-the-art approaches. Furthermore, the proposed compressive receding horizon strategy fully exploits weather and photovoltaic generation forecasts to promote self-consumption and grid demand stress reduction while providing environmental gains and financial benefits to the utility service and consumers, particularly in the case of simultaneously scheduling a huge number of households.publishersversionpublishe

PERSPECTIVES ON THE PROSUMER ROLE IN THE SUSTAINABLE ENERGY SYSTEM

Climate change and the ever-growing demand for energy are pushing us to find new ways to manage energy production, distribution, and consumption. This energy transition is enabled, for example, by the digitalization, decentralization, and democratization of the energy system. The energy system is already transitioning from fossil-fuel and large power-plant–based generation toward a flexible system based on renewable energy sources. Traditional transmission grids are being replaced by smart grids enabled by digitalization that facilitate bi-directional flows of information and energy. At the consumption end, smart energy meters, energy monitoring devices and applications, and renewable energy technologies such as solar photovoltaic and battery storages empower energy consumers to evolve into prosumers: the producers and consumers of energy. These prosumers, also referred to as active consumers and energy citizens, are envisioned to play an important role in the sustainable energy system in the future. While the energy prosumer role has gained more research attention during the past few years, plenty of gaps in completely understanding energy prosumerism still remain. This research focuses on studying the prosumer role in the sustainable energy system. I study the enablers and activities of energy prosumers and explore how the growing number of prosumers may influence the socio-technical energy transition. The research presents two main perspectives on prosumerism; it explores both the micro and macro-level influences on the energy prosumers. The main research fields of this study are sustainability transitions, innovation studies, and policy. Based on theory and literature review, a novel research framework synthesizing the theoretical concepts and earlier research related to prosumers is introduced. From the methodology viewpoint, a pragmatic research approach and mixed methods are used to explore the enablers for prosumerism as well as prosumer activities and their impact on the ongoing energy transition. The research results are displayed in the form of six articles published in international peer-reviewed journals and conferences. The first two articles make propositions about the prosumer role as part of the changing socio-technical energy and innovation system. The next two articles focus on understanding the micro-level impact on the energy prosumers and examine the producer–consumer, in particular, as a co-developer of energy-related innovations. The remaining two articles address the impact of macro-level policies on prosumers. Overall, this research contributes to the understanding of the energy prosumer role in the future sustainable energy system. Theoretical contributions are related to the novel research framework that combines the concepts from the socio-technical multi-level perspective, innovation studies, and policy research as well as offers a more pragmatic framework for inquiry in the context of the changing energy system to observe the prosumer role therein. A specific theoretical contribution is made to the technology acceptance model that is tested in the context of external policy influence. Furthermore, the research contributes to innovation studies and especially to the field of user-centric innovations by bringing new results for understanding the factors behind end users’ collaboration interests. Practical contributions of the study are related to the understanding of the micro-foundations of prosumer interests toward innovation co-creation activities. Practitioners benefit from evidence concerning the differences between consumers and prosumers, which may help them in designing products and services for these different categories. This improved understanding is necessary, for example, to accelerate the diffusion of renewable energy technologies that is crucial for the sustainability transition. Policy- makers may benefit from the findings related to the policy analysis that combines and compares different prosumer activities with policy mixes and calls for a more holistic and systemic approach for the development of the prosumer related policies. While prosumer research has increased during the past decade, many future research avenues for the topic exist. For example, more research on prosumer role as part of the sustainability transition can help in designing better policies as well as products and services for consumers and prosumers. Moreover, systemic activities, such as those related to the integration of electric vehicle smart charging into the power system combined with other prosumer activities, offer opportunities for researchers. Furthermore, research concerning novel prosumer-centric business models, for instance related to energy communities, is needed to accelerate the diffusion of sustainable technology solutions. -- Ilmastomuutos ja kasvava energian kysyntä ajavat meidät etsimään uusia tapoja hallita energian tuotantoa, jakelua ja kulutusta. Energiajärjestelmä onkin jo siirtymässä fossiilisten polttoaineiden ja suurten voimalaitosten tuotannosta uusiutuviin energialähteisiin perustuvaan joustavaan järjestelmään. Sähköverkot on transformoitu digitalisoinnin mahdollistamana älykkäiksi Smart Grid -verkoiksi, jotka pystyvät siirtämään sekä energiaa että dataa molempiin suuntiin tuotannon ja kulutuksen välillä. Kulutuspäässä älykkäät energiamittarit, seurantalaitteet ja - sovellukset sekä uusiutuvien energialähteiden teknologiat, kuten aurinkosähkö ja akkuvarasto, antavat energiankuluttajille mahdollisuuden kehittyä prosumereiksi eli energian tuottaja-kuluttajiksi (engl. prosumer = producer-consumer). Prosumereilla, joihin viitataan myös nimillä ”aktiivinen kuluttaja” ja “energiakansalainen”, on tulevaisuudessa tärkeä rooli kestävässä energiajärjestelmässä. Vaikka prosumerit ovat saaneet lisää huomiota tutkimuksessa viime vuosina, energia prosumerismin ymmärtämisessä on vielä paljon aukkoja. Tämä tutkimus keskittyy selvittämään prosumerien roolia osana kestävää energiajärjestelmää ja sen murrosta. Tutkin prosumereihin liittyviä mahdollistajia, prosumerien toimintaa osana energiajärjestelmää sekä vaikutuksia kestävän kehityksen energiamurrokseen. Tutkimus on luonteeltaan monialainen, yhdistäen innovaatiotutkimusta, transitiotutkimusta ja myös jossain määrin politiikantutkimusta. Tässä pragmaattisessa tutkimuksessa käytetään sekä kvantitatiivisia että laadullisia tutkimusmetodeja. Tutkimuksen tulokset esitetään liitteenä olevien kuuden vertaisarvioidun konferenssi ja -journaaliartikkelin avulla. Ensimmäiset kaksi artikkelia esittävät propositioita prosumerin roolista osana muuttuvaa sosio-teknistä energia- ja innovaatiopelikenttää. Seuraavat kaksi artikkelia keskittyvät ymmärtämään mikrotason vaikutusta näihin toimijoihin ja tutkivat erityisesti energiaan liittyvien innovaatioiden yhteiskehittämistä. Lopuksi kaksi artikkelia käsittelevät makrotason politiikkatoimien vaikutusta prosumereihin. Tutkimuksen pääkontribuutio on ymmärryksen lisääminen kuluttajan muuttuvasta roolista osana energiajärjestelmää. Teoriakontribuutiot kytkeytyvät uusiin tapoihin yhdistää keskeisiä teorioita kestävän kehityksen transitiotutkimuksesta, innovaatiotutkimuksesta sekä politiikan tutkimuksesta. Käytännön elämään vaikuttavat kontribuutiot liittyvät empiirisiin tutkimustuloksiin esimerkiksi tavallisten kuluttajien ja prosumereiden eroista. Tietämyksen lisääminen auttaa teknologia- ja palveluyrityksiä suunnittelemaan tuotteita ja palveluita, jotka sopivat erilaisiin tarpeisiin, joka voi edelleen auttaa nopeuttamaan uusiutuvaan energiaan liittyvien innovaatioiden leviämistä ja siten edistää kestävää kehitystä. Prosumer -tutkimuksessa on edelleen paljon tilaa uudelle tieteenharjoitukselle. Esimerkiksi energiayhteisöt ovat yleistymässä ja tutkimus niiden roolista osana energiajärjestelmää on vasta käynnistynyt. Tutkimalla energiayhteisöjä pystytään lisäämään ymmärrystä niiden vaikutuksesta esimerkiksi sähköverkkoon ja lainsäädäntöön. Toisaalta myös yksittäisten aktiviteettien ja ajureiden tutkimuksessa on vielä paljon mahdollisuuksia. Esimerkiksi systeemiset ja integroidut ratkaisut, kuten sähköautojen käyttäminen osana kysyntäjoustoa, tarjoavat hyviä tutkimusaiheita. Lisäksi erityisesti uudet liiketoimintamallit liittyen prosumereihin ja energiayhteisöihin kaipaavat selkeyttämistä ja kokeiluja sekä regulaation muunnoksia