Contribution to the operation of smart rural distribution grid with energy resources for improvement of the quality of service

This Thesis aims for contributing in the deployment and operation of Smart Grid, in isolated rural areas. As it would be expected, technological developments and investments in the electrical field have mainly focused on urban and industrial areas where the energy demand is high, as well as, the possibility to recover easily the investment. Therefore, difficult accessing areas where population and electrical demand are low are less attractive to invest. For this reason, this Thesis, in parallel to the European project known as Smart Rural Grid, has focused on the rural grid development. In this sense, the Thesis contributes directly in the design, conception and justification of an innovate architecture for rural systems. The architecture has been deployed and tested at the end of a medium voltage line of Estabanell Energia in Vallfogona del Ripollès. In addition, the presented architecture is characterised to integrate power electronics with embedded battery systems, an innovative management system and a proper telecommunication network in order to gain robustness, flexibility and hosting capacity for distributed and renewable generation. To sum up, the Thesis has focused on the design and development of new operation modes, algorithms and equipment that allow to manage automatically and optimally the energy resources; like power electronics, energy storage systems, distributed and renewable generation, and controllable loads. These strategies are able to correct common issues in rural grids, such as voltage variations and electrical losses. In addition, they improve and ensure the power quality and supply continuity, contribute to reduce operational costs and infrastructure optimization and deferral.Aquesta tesi vol contribuir en el desplegament de les futures xarxes elèctriques intel.ligents, en entorns rurals que habitualment són oblidats. Cal mencionar que els principals avenços tecnològics i les inversions per part dels gestors de la xarxa s'han centrat en entorns urbans i industrials, ja que aquests solen demandar grans quantitats d'energia, fet que facilita la recuperació de la inversió. Per tant, en un entorn on la densitat de població i la demanda energètica és baixa i a més l'orografia és complexa resulta menys atractiu invertir-hi. Per aquest motiu, la tesi, en paral.lel al projecte Europeu Smart Rural Grid, s'ha centrat en el desenvolupament de les xarxes elèctriques en entorns rurals. El principal objectiu de la tesi i alhora del projecte Smart Rural Grid és desenvolupar tecnologies per concebre les futures xarxes en entorns rurals. Aquestes han de permetre incrementar la baixa eficiència, qualitat i resiliència de la xarxa. En aquest sentit, la tesi ha contribuït en la concepció, disseny i justificació d'una innovadora arquitectura. Aquesta arquitectura, s'ha dut a terme en el final d'una línia de mitja tensió d'Estabanell Energia a Vallfogona del Ripollès. A més, aquesta arquitectura es caracteritza per integrar electrònica de potència, sistemes elèctrics d'emmagatzemament, un innovador sistema de gestió i de telecomunicacions, poden proporcionar a la xarxa una major robustesa, flexibilitat i capacitat per integrar a la nova generació distribuïda i renovable. D'altre banda, la Tesi també s'ha centrat en la concepció i desenvolupament de nous modes d'operació, algoritmes i dispositius que permeten automatitzar i optimitzar la gestió dels recursos distribuïts; és a dir, la electrònica de potència, els sistemes d'emmagatzemament, la generació renovable i distribuïda i les càrregues controlables. Aquestes estratègies permeten solventar els problemes habituals en aquest tipus de xarxes, com per exemple les variacions de tensió i les pèrdues. A més, també milloren i asseguren la qualitat i continuïtat del subministrament, ajuden a reduir els costos d'operació i retrassar la inversió en nova infraestructur

Risk-based assessment for distribution network via an efficient Monte Carlo simulation model

Given the fact that Smart Grid technologies are implemented mainly in distribution networks, it is essential to build a risk-based assessment tool which can model the operational characteristics of distribution networks operation. This thesis presented a distribution network model which captures the features of distribution network restoration, based on approximations of real-time switching actions. It enables the evaluation of complex distribution network reliability with active network control. The development of an explicit switching model which better reflects actual network switching actions allows for deliberate accuracy and efficiency trade-offs. Combined with importance sampling approach, a significant improvement in computational efficiency has been achieved with both simplified and detailed network switching models. The assessment model also provides flexibility for users to analyse system reliability with various levels of complexity and efficiency. With the proposed assessment tool, different network improvement technologies were investigated for their values of substituting traditional network constructions and impacts on network reliability performances. It has been found that a combination of different technologies, according to specific network requirements, provide the best solution to network investments. Models of customer interruption cost were analysed and compared. The study shows that using different cost models will result in large differences in results and lead to different investment decisions. A single value of lost load is not appropriate to achieve an accurate interruption cost quantification. A chronological simulation model was also built for evaluating the implications of High Impact Low Probability events on distribution network planning. This model provides the insights for the cost of such events and helps network planners justify the cost-effectiveness of post-fault corrections and preventive solutions. Finally, the overall security of supply for GB system was assessed to investigate the impacts of a recent demand reduction at grid supply points (for transmission networks) resulting from the fast growing of generation capacity in distribution networks. It has been found that the current security standard may not be able to guarantee an acceptable reliability performance with the increasing penetration of distributed generation, if further balancing service investment is not available.Open Acces

Developing Wind Power in Finland : ABB's approach from the grid connection perspective

This thesis was done for ABB OY. It is a snapshot of the Finnish wind power market in 2014. The market is blooming, and the wind power developers are aiming to get the planned wind power parks connected to the national grid in short order. The scope of this thesis includes the electrical balance of the plant (EBoP), but excludes the turbine itself. The goal was to understand the techno-economic process of the developer in order to achieve optimal grid connection design and to be of better service to the customers. Several wind power professionals were interviewed to gather the study material, and the recurring themes were highlighted for discussion. The premise was that there are “blind spots” in the co-operation with ABB and the customer that need to be acknowledged. When the developer’s business environment is mapped out, suggestions can be made to further improve the ABB practices. Many of the services desired by customers already exist in the ABB portfolio, but unifying the extensive offering seems laborious. A complete wind service concept was created to offer insight on how to start improving the approach to the wind power industry in Finland. Productised service packages with standardized ABB Wind Products and designated ABB Wind personnel are in the core of this concept. More effort needs to be put to drive these changes as the growing market is demanding for more comprehensive service through the entire life cycle of the wind power park.Tämän insinöörityön toimeksiantajana toimi ABB OY ja se on tilannekatsaus Suomen tuuli-voimamarkkinoihin vuonna 2014. Markkina kasvaa Suomessa ja tuulivoiman hankekehittä-jät pyrkivät liittämään tuulipuistojaan kansalliseen sähköverkkoon kiihtyvällä tahdilla. Tämä työ koskee ainoastaan voimalan verkkoliitäntää, eikä työssä käsitellä itse tuuliturbiineita. Työn tavoite oli ymmärtää hankekehittäjän teknis-taloudellista prosessia syvemmin. Tämä mahdollistaisi verkkoliitännän suunnittelun optimoinnin sekä paremman palvelun tarjoamisen asiakkaille. Materiaali kerättiin haastattelemalla useita tuulivoima-alan ammattilaisia, jonka jälkeen haastatteluissa toistuvia teemoja nostettiin esiin. Lähtökohta työlle oli, että asiakkaan ja ABB:n välisissä yhteyksissä olisi kehitettävää. ABB:n lähestymistapaa voitiin käsitellä tarkemmin, kun hankekehittäjän liiketoimintaympäristöä oli ensin kartoitettu. Työ osoitti, että monet asiakkaiden toivomista palveluista löytyvät jo ABB:n portfoliosta. Tarjonnan yhtenäistäminen on kuitenkin työlästä. Yhtenä työn tuloksista syntyi kattava tuu-livoiman palvelukonsepti. Konsepti tarjoaa ehdotuksia siitä, kuinka ABB voisi kehittää toi-mintaansa palvellessaan tuulivoima-asiakkaita Suomessa. Tuotteistetut palvelupaketit standardoiduilla ABB:n tuulivoimatuotteilla sekä nimetyt tuulivoima-asiakkaiden kontaktihenkilöt ovat konseptin ytimessä. Lisää työtä on tehtävä, jotta muutoksia toimintatapoihin saadaan ajettua läpi. Kasvava liiketoimintaympäristö ja tuulivoiman hankekehittäjät vaativat laajempia ratkaisuja koko tuulivoimapuiston elinkaaren ajalle

Untapping the full potential of solar farms in the UK: different approaches to land management

The United Kingdom (UK) Government’s strategic to meet the target of 15 per cent renewable of primary energy from final consumption by 2020, and help the delivery of carbon reductions, have introduced support mechanism. These support mechanism includes: Feed-in Tariffs (FiT), Renewable Obligation (RO) and Contracts for difference (CfD). The increase installation of utility-scale photovoltaic (PV) plants and the competition between food and energy brought an important topic for discussion the full potential of solar farms. Once after installation of the infrastructure around 70% of ground remains available, so this project proposes and analyses the different approaches to land management. The land management suggestions are agricultural use (crops, grazing and beekeeping) and biodiversity use (hedgerows, security fencing, field margins, grassland (wildflowers meadow) and nest boxes). A number of impacts during the solar development cycle (development phase, construction phase and operational and maintenance phase (O&M) and the environmental, land-use, biodiversity and socio–economic impacts, are studied and analysed for each of the possible options for ground. The suitable use is selected by developers, so the impacts of the different land management studies on are devices to help them in this decision. Therefore any land management option, however expensive is their implementation or maintenance is preferable than just cutting the vegetation, where there is no land management use.Até 2020 cerca de 15% da energia primária consumida no Reino Unido terá de ser produzida a partir de fontes renováveis. Para ajudar a atingir essa meta, e de forma a reduzir as emissões de carbono, foram introduzidos mecanismos de suporte. Estes mecanismos incluem: FIT, RO e CFD. O aumento das instalações fotovoltaicas de grande escala e a competição entre alimentos e energias trouxeram um importante tópico de discussão: o potencial dos parques solares. Uma vez que após a instalação da estrutura cerca de 70% do terreno permanece disponível, este relatório de estágio propõe-se a analisar as diferentes abordagens da ocupação do solo. As diferentes ocupações do solo sugeridas são o uso agrícola (colheitas, pastoreio e apicultura) e para o uso da biodiversidade (sebes, cercas de segurança, margens de campo, pastagens (prado de flores silvestres) e ninhos para pássaros e morcegos). Sendo estudados e analisados uma série de impactos durante o processo de desenvolvimento de uma planta PV (fase de desenvolvimento, EPC, O&M) e os impactos: ambientais, estrutura do solo, biodiversidade e socioeconómicos, relativamente a cada uma das opções possíveis de ocupação de solo. Acabe aos planeadores a decisão da melhor ocupação do solo, sendo os impactos dispositivos que irão ajudar nessa decisão. Conclui-se que a opção de gestão da ocupação do solo, por mais dispendiosa que seja a sua implementação ou manutenção, é preferível do que unicamente a remoção da vegetação onde não há uso do solo

Discussion on Electric Power Supply Systems for All Electric Aircraft

The electric power supply system is one of the most important research areas within sustainable and energy-efcient aviation for more- and especially all electric aircraft. This paper discusses the history in electrication, current trends with a broad overview of research activities, state of the art of electrication and an initial proposal for a short-range aircraft. It gives an overviewof the mission prole, electrical sources, approaches for the electrical distribution system and the required electrical loads. Current research aspects and questions are discussed, including voltage levels, semiconductor technology, topologies and reliability. Because of the importance for safety possible circuit breakers for the proposed concept are also presented and compared, leading to a initial proposal. Additionally, a very broad review of literature and a state of the art discussion of the wiring harness is given, showing that this topic comes with a high number of aspects and requirements. Finally, the conclusion sums up the most important results and gives an outlook on important future research topics

Advanced methods for offshore windfarm planning

There have been increasing interests and projects of Offshore wind farm (OWF) development across the world given the rich wind resources in order to achieve carbon neutral objectives. Appropriate electrical system design of OWF is of key importance in terms of cost saving and improving system efficiency. Two novel electric system layout optimization models for OWF planning are proposed to optimize the topology of collector system and connected transmission system simultaneously in OWFs with single and multiple substations. For OWF with single-substation, a novel mathematical model to represent the system topology is proposed to reduce the number of variables so as to effectively decrease the search space of the optimisation problem, where the continuous substation sitting problem is discretized by a 2-step rasterization method. For large-scale OWFs, the overall electric system optimization problem has been classified into 3 levels: substation optimization, feeder selection, and cable determination. Fuzzy clustering technique and wind turbine allocation method has been proposed to effectively divide the large offshore windfarms into partitions. Both HVDC and HVAC cables are considered as alternatives used in the associated transmission system, which can be optimized at the substation level. The concept of clustering is further applied in feeder level to cluster wind turbines into appropriate feeders. The proposed model and the optimization algorithms are tested and validated in two large-scale offshore winds. A comprehensive decision support model is proposed which covers three key factors that characterize OWF integration: investment cost, system stability and the interactions between MTDC and local AC system, all of which are concerned to characterize the optimal integration location of wind turbines into AC bus location and appropriate converter size installed at the corresponding MTDC terminals. To better fit into the real-world situation, various wind speed and load scenarios have been considered. Validity and effectiveness of the proposed model has been tested to integrate two wind farms to a benchmark AC system via a MTDC grid. The research methodologies presented in the thesis form a rather comprehensive approach for OWF design and planning. With the rapid development in OWF technologies, future research needs are also identified and presented in the thesis

HVDC transmission : technology review, market trends and future outlook

HVDC systems are playing an increasingly significant role in energy transmission due to their technical and economic superiority over HVAC systems for long distance transmission. HVDC is preferable beyond 300–800 km for overhead point-to-point transmission projects and for the cable based interconnection or the grid integration of remote offshore wind farms beyond 50–100 km. Several HVDC review papers exist in literature but often focus on specific geographic locations or system components. In contrast, this paper presents a detailed, up-to-date, analysis and assessment of HVDC transmission systems on a global scale, targeting expert and general audience alike. The paper covers the following aspects: technical and economic comparison of HVAC and HVDC systems; investigation of international HVDC market size, conditions, geographic sparsity of the technology adoption, as well as the main suppliers landscape; and high-level comparisons and analysis of HVDC system components such as Voltage Source Converters (VSCs) and Line Commutated Converters (LCCs), etc. The presented analysis are supported by practical case studies from existing projects in an effort to reveal the complex technical and economic considerations, factors and rationale involved in the evaluation and selection of transmission system technology for a given project. The contemporary operational challenges such as the ownership of Multi-Terminal DC (MTDC) networks are also discussed. Subsequently, the required development factors, both technically and regulatory, for proper MTDC networks operation are highlighted, including a future outlook of different HVDC system components. Collectively, the role of HVDC transmission in achieving national renewable energy targets in light of the Paris agreement commitments is highlighted with relevant examples of potential HVDC corridors

The economic cost of unreliable grid power in Nigeria

The ever-increasing demand for electrical power in Nigeria, coupled with a limited supply, have restricted the nation's socioeconomic development. The country’s policymakers, aware of this, have formulated and enacted energy development policies in recent years targeted at diversifying the current electricity mix and increasing electrification to rural settlements. Despite these efforts, electricity infrastructure projects have been sidelined, power outages are common and grid unreliability is costing industry significant amounts to secure the electricity supply necessary for business sustainability and profitability. This paper presents the current state of the electricity industry in Nigeria and argues the case for integration of renewable energy technologies. A case study is presented based on electricity cost information collected from a survey of Nigerian industry. Three future electricity supply scenarios are presented: a do-nothing or business-as-usual scenario; a scenario of increased reliance on grid power due to improvements in reliability; and a scenario involving shifting some of the current diesel on-site generation to solar photovoltaics. It is shown that increasing the utilization of renewable sources could significantly reduce the costs and CO2 emissions incurred due to the current reliance on self-generation, primarily using diesel generators, amidst grid unreliability

Development of Electrical Hazard and Probability (ELHAP) Tool Related to Equipment and System Failure

Electrical safety in the industrial process plant plays an important role to ensure overall safety of the chemical plant, but most of the time this subject has been largely ignored leading to major accidents in the plant. Due to this reason, many researchers find that it is important to understand completely the electrical system to avoid any accident in the plant. Hazard and Operability (HAZOP) analysis tool is widely used as qualitative tool to identify potential hazards that can cause major accidents in the plant, while the Fault Tree Analysis (FTA) method is widely used to estimate the probability of occurrences of the hazards. However, they have never been implemented vigorously to identify potential hazards due to electrical equipment and system failure. Thus, the main objective of this project is to provide a framework for systematic investigation of the problems in process plant due to electrical equipment and system failure. This project consists of analysis that is done to complement the need for detailed study of the electrical hazard. The analysis will include both qualitative HAZOP analysis approach to identify the possible hazards and a quantitative FTA assessment to rank the hazardous event accordingly for direct implementation in industrial case study. The tools developed will provide a detail review of chemical plant safety focusing on electrical equipments and system design. At the end of the study, the analysis will help to provide suggestion to improve the design, installation, operation and maintenance procedures in order to optimize the safety and operability in the plant. i

Sähkönsiirtoverkko-omaisuuden kunnonvalvontajärjestelmä Esineiden Internet -alustalla

Fingrid is making the transition from time-based maintenance to condition-based maintenance in order to increase the cost-efficiency of substation asset condition management and to prevent equipment failures. Digitalization improves real-time visibility to asset condition as Fingrid is developing an Internet of Things (IoT) concept for online asset condition monitoring. The objective of this Thesis was to specify Fingrid's requirements for asset condition data visualization in an Asset Performance Management (APM) application. A secondary objective was to document Fingrid's IoT concept and existing condition monitoring practices. Asset maintenance strategies, digitalization and Internet of Things were discussed as a background. For the IoT data of switchgear, simple illustrations of dashboards were drawn to show how the data could be visualized in an APM application. Regarding power transformers, the necessary basic elements for condition data visualization were reviewed. Specifications for visualization of all the available condition data were listed in Appendices. Online condition monitoring is currently concentrated on switchgear, power transformers and substation buildings. The IoT solution for switchgear consists of low-cost sensor units installed in switchgear control cabinets and bay marshalling cabinets. Power transformers are equipped with online DGA (Dissolved Gas Analysis) instruments which is a well-established practice. In substation buildings, the climate is monitored with low-cost IoT sensors. The conclusion of the study was that there are two types of condition data that determine Fingrid's requirements for data visualization in an APM application: time series data and event data. Monitoring of continuous processes produces a large amount of continuous time series data. A tool with efficient functionalities for time series data presentation and analysis is needed. Switchgear operations and oil sampling produce event data that require visualization in forms of data reporting and special analyses. The amount of event data is small even though it will increase due to IoT.Fingrid on siirtymässä aikaperusteisesta sähköasemien kunnossapidosta kuntoperusteiseen kunnossapitoon kustannustehokkuuden parantamiseksi ja laitevikojen ennalta ehkäisemiseksi. Reaaliaikaista näkyvyyttä omaisuuden kuntoon parannetaan kehittämällä "Esineiden Internet" (\textit{engl. Internet of Things, IoT}) -konsepti omaisuuden käytönaikaiseen kunnonvalvontaan. Tämän diplomityön tavoitteena oli laatia määrittelyt kunnonvalvontadatan visualisoinnille omaisuuden kunnonvalvontajärjestelmässä. Toisena tavoitteena oli dokumentoida Fingridin IoT-konsepti ja käytössä olevat perinteiset kunnonvalvontamenetelmät. Taustana työlle esiteltiin omaisuuden kunnonhallintamalleja, digitalisaatiota ja Esineiden Internetiä. Kytkinlaitteiden IoT-datan visualisoinnin tarpeiden hahmottamiseksi laadittiin luonnoksia kunnonvalvontajärjestelmän näkymistä. Muuntajien kunnonvalvonnan tarpeelliset osa-alueet kunnonvalvontajärjestelmässä käytiin läpi käytössä olevia ratkaisuja tutkimalla. Määrittelyt kaiken käytettävissä olevan kunnonvalvontadatan visualisoinnille listattiin työn liitteissä. Käytönaikainen kunnonvalvonta keskittyy tällä hetkellä kytkinlaitteisiin, muuntajiin ja sähköasemarakennuksiin. Kytkinlaitteiden IoT-ratkaisu koostuu kytkinlaitteen ohjainkaappiin sekä kytkinkentän jakokaappiin asennetuista kustannustehokkaista sensoriyksiköistä. Muuntajat on varustettu jatkuva-aikaisella vikakaasujen seurannalla, mikä on toimivaksi todettu ja vakiintunut kunnonvalvontamenetelmä. Asemarakennusten olosuhteita valvotaan huoneisiin sijoitetuilla IoT-sensoriyksiköillä. Työn johtopäätöksenä voidaan todeta kunnonvalvontadatan jakaantuvan pääasiassa kahteen muotoon, jotka määrittelevät Fingridin tarpeet kunnonvalvontajärjestelmälle. Jatkuva-aikaisten prosessien valvonta tuottaa suuren määrän jatkuvaa aikasarjadataa, minkä vuoksi tehokkaat työkalut aikasarjadatan esittämiselle ovat tarpeen. Kytkinlaitteiden ohjaukset ja muuntajien öljynäytteet puolestaan tuottavat tapahtumaperusteista dataa, jonka visualisointi muistuttaa datan raportointimenetelmiä. Tarvitaan erilaisia datan esitystapoja ja mukautettuja analysointimenetelmiä. Tapahtumadatan määrä on pieni siitä huolimatta, että sen määrä kasvaa huomattavasti IoT:n myötä