Le Dynamic Line Rating est la modification dynamique des contraintes de courant sur une ligne électrique aérienne, en accord avec la météorologie. De telles modifications permettent alors d’avoir des réductions des phénomènes de congestion près de 99% du temps.De manière similaire aux énergies renouvelables, il est possible de générer des prévisions de ces contraintes modifiées, en accord avec des observations historiques, des prévisions météorologiques et des méthodes d’intelligence artificielle.Dans cette thèse, nous proposons le développement de modèles de prévision probabilistes à court terme du DLR. Nous nous concentrons plus particulièrement sur des méthodes fournissant des prévisions ayant de très faibles probabilités d’être surestimées. Cela passe par le développement et la comparaison de plusieurs méthodes de prévision, ainsi que des améliorations comme des modifications de prévisions à très bas quantile à l’aide de remodélisations des queues de distribution.Par la suite, une réflexion est faite sur l’utilisation en pratique de ces prévisions, d’abord par des cas d’étude simplifié, puis à l’aide de simulations de réseaux électrique. Ces approches nous permettent de développer de nouvelles stratégies d’utilisation des prévisions DLR, optimisant le bien-être social tout en maintenant les risques associés aux erreurs de prévision à un niveau faible.Finalement, nous évaluons les modèles de prévisions développés en fonction de leurs performances économiques à l’aide des modèles de réseaux électriques, et nous démontrons la valeur des améliorations des modèles de prévision que nous proposons. / Dynamic Line Rating is the modification of the maximal current capacity of an overhead electrical line, depending on weather characteristics. Such modifications allow important decreases of congestion phenomena, around 99% of the time.Similarly to renewable generation, it is possible to forecast the modified constraints, accordingly to some historic observations, weather predictions and artificial intelligence methods.In this document, the development of short-term probabilistic DLR forecast models. A focus is especially made on methods providing forecasts having a very low probability of being overestimated. This is made through the development and the comparison of several forecast methods, and some improvements such as the remodelling of very low quantile forecasts with tail density modelling.Following that, a reflection is proposed on the use of such forecasts in practice, first with some simplified test cases, then with electrical grid simulations. These approaches allow us developing new strategies for the use of the DLR forecasts, maximizing the social welfare while keeping risks associated with forecasts errors at low levels.Finally, an evaluation of the forecast models function of their economic value is made with the electrical grids models, and the value of the proposed modifications of the forecast models is then demonstrated.

Current flow in the electrical grid is changing due to the introduction of new generators and loads.Specifically, weak Overhead lines, are a constraint for the introduction of wind farms located farfrom the central network. The current situation requires smart solutions to improve the transportationcapabilities of these grid’s components. Among the different possibilities, Dynamic Line Rating(DLR), is emerging as the most interesting solution from both the economic and technical points ofview. The presented Thesis work investigates the performance of DLR from both the theoretical andpractical perspectives.The theory behind DLR is based on the development of a thermal model able to estimate the precisetemperature experienced by OHLs conductor under different climate conditions. Since 1972, whenthe first investigation on DLR have been published, different thermal models have been developed,each with a different precision level. The first part of the thesis concerns the investigation of IEEE738 standard accuracy.The standard analysis highlighted weaknesses on the theoretical approach employed on the forcedconvective cooling calculation. Specifically the wind direction effect is estimated as the conductorwas a perfect cylinder. A wind tunnel test has been performed in order to verify the effect of theconductor’s strands on the total thermal equilibrium. The results show that an inclined wind-conductor relative direction can have a more important impacton the line rating than foreseen with the IEEE thermal model. Since the wind tunnel test has been thefirst experience of this kind pursued at KTH, the presence of few different laboratory set-updeficiencies did not allow to draw a definitive and precise conclusion on the necessary IEEE formulacorrection.The practical side of the Thesis project includes an extensive literature research on the differentdevices that can be employed for dynamic line rating and a real-case study analysis. The analysis isperformed in order to evaluate which can be the best solution when the introduction of new windenergy supply increase the load on a pre-existent OHL. Results show that, in the selected region,Värmland, in the southwestern Sweden, DLR has the prerequisites to allow the exploitation of thehigh wind energy resource at the lower expenses. Wind energy production is often associated with anincreased cooling on the line’s conductors. This means that higher current levels can be withstoodavoiding the need for expensive lines’ upgrading. For the selected hot-spot, in 2015, DLR wouldhave allowed a transport capability improvement of 69.6% during the summer and of 26.7% duringthe winter. It is also reported that a load equal to the SLR during the winter period would have causedserious overheating transients of the conductor. Overall DLR proved to allow technical and economicbenefit for the system operator. / Flödet genom elnätet förändras på grund av införandet av ny generering och nya typer av laster.Specifikt är svaga luftledningar en begränsning för installation av vindkraft som ligger långt fråndet centrala nätet. Den nuvarande situationen kräver smarta lösningar för att förbättratransportkapaciteten i elnätet. Bland de olika möjligheterna finns Dynamic Line Rating (DLR) somframstår som den mest intressanta lösningen från både ekonomiska och tekniska synvinklar. Det härexamensarbetet behandlar resultatet av DLR från både teoretiska och praktiska perspektiv.Den teoretiska grunden för DLR är baserad på utvecklingen av en termisk modell som kan skattatemperaturen i luftledningar under olika klimatförhållanden. Examensarbetets första del behandlaren undersökning av IEEE 738 standarden (DLR standard). IEEE 738 standarden utgår från ledarensom en perfekt cylinder. Något som har en effekt bland annat i effekten av vindriktning. Ettvindtunnel test har utförts för att verifiera effekten av fler kardelers effekt på den totala termiskajämvikten. Resultaten visar att antalet kardeler har en betydande effekt på den termiska jämviktenoch då alltså även på DLR.Den andra delen av examensarbetet innehåller en omfattande litteratursökning på de olikaapparaterna som kan användas till DLR samt en praktik undersökning/analys. Analysen utförs föratt utvärdera vilken lösning som kan vara den bästa vid införandet av mer vindkraft, som ökarbelastningen på en redan existerande luftledning. Resultaten visar att, i det valda området,Värmland, i sydvästra Sverige, har DLR förutsättningar för att medge ökat utnyttjandet av den storavindkraft resurs som finns där till relativt låga kostnader. Slutsatsen av examensarbetet är att DLR ger tekniska och ekonomiska fördelar tillsystemoperatören.

There is an ever increasing demand of electricity and to meet this demand, installation of new transmission and distribution lines is required. This task requires a significant investment and consent from the respective authorities. An alternative is to utilize maximum capability of the existing lines. Static line ratings are based on a conservative estimate, which means that on most occasions, the actual capacity of lines is much higher than the static line ratings. In order to provide a solution to this problem, this thesis introduces an approach that has been developed to utilize real time weather conditions, conductor sag data and the actual line loading of the conductor from PMU to provide dynamic line ratings for active distribution networks. The application has been developed in LabVIEW environment which provides a user friendly front panel where real-time ampacity can be seen as a waveform while being compared to the actual line loading.  The developed application has been tested on the reference grid created for IDE4L project. The ampacity calculation method introduced here makes use of real-time data available through a real-time simulator in SmarTS lab at KTH, Sweden. / Det är ett ökande behov av elektricitet och för att möta detta behövet, installation av nya transmission och distributionsledningar behövs. Denna utbyggnad kräver ett stort engagemang och förståelse från ansvariga grupper. Ett alternativ är att utnyttja max-kapaciteten på redan befintliga ledningar. Installerade ledningar har räknats på ett konservativt sätt, vilket innebär att det vid vissa tillfällen går att öka belastingen på på dessa. För att ge en lösning på detta problem, introducerar den här avhandlingen en metod för att använda realtids-väderdata, tabeller för ledningarnas utvidgning och realtids-belastningsdata från PMU för att framställa dynamisk data för aktiva distributions-nätverk. Applikationen har utvecklas i LabVIEW-miljön som har ett användarvänligt GUI, där “Real-time ampacity” kan ses som en vågform medans den jämförs mot den faktiska belastningen på ledningen.  Den utvecklade appliktionen har testats på referens-miljön som skapts för IDE4L projektet. “Ampacity calculation metoden” som introduceras här använder sig av realtidsdata som görs tillgänglig igenom en realtids-simulator i SmarTSlab på Kungliga Tekniska Högskolan i Sverige.

The traditional power systems are statically rated and sometimes renewable energy sources (RES) are curtailed in order not to exceed this static rating. The RES are curtailed because of their intermittent character and therefore, it is difficult to predict their output at specific time periods throughout the day. Dynamic Line Rating (DLR) technology can overcome this constraint by leveraging the available weather data and technical parameters of the transmission line. The main goal of the thesis is to present prediction models of Dynamic Line Rating (DLR) capacity on two days ahead and on one day ahead. The models are evaluated based on their error rate profiles. DLR provides the capability to up-rate the line(s) according to the environmental conditions and has always a much higher profile than the static rating. By implementing DLR a power utility can increase the efficiency of the power system, decrease RES curtailment and optimize their integration within the grid. DLR is mainly dependent on the weather parameters and specifically, in large wind speeds and low ambient temperature, the DLR can register the highest profile. Additionally, this is especially profitable for the wind energy producers that can both, produce more (until pitch control) and transmit more in high wind speeds periods with the same given line(s), thus increasing the energy efficiency.  The DLR was calculated by employing modern Data Science and Machine Learning tools and techniques and leveraged historical weather and transmission line data provided by SMHI and Vattenfall respectively. An initial phase of Exploratory Data Analysis (EDA) was developed to understand data patterns and relationships between different variables, as well as to determine the most predictive variables for DLR. All the predictive models and data processing routines were built in open source R and are available on GitHub. There were three types of models built: for historical data, for one day-ahead and for two days-ahead time-horizons. The models built for both time-horizons registered a low error rate profile of 9% (for day-ahead) and 11% (for two days-ahead). As expected, the predictive models built on historical data were more accurate with an error as low as 2%-3%.  In conclusion, the implemented models met the requirements set by Vattenfall of maximum error of 20% and they can be applied in the control room for that specific line. Moreover, predictive models can also be built for other lines if the required data is available. Therefore, this Master Thesis project’s findings and outcomes can be reproduced in other power lines and geographic locations in order to achieve a more efficient power system and an increased share of RES in the energy mix

It is important to keep an overhead power line within rated operating conditions. Thus,an accurate prediction of the conductor's thermal and electrical behavior leads to an increasein reliability and eciency. Under DLR operation, the current rating is adjustedbased on ambient weather and solar conditions to allow for dynamic line loading. Therating adjustment takes into account the cooling mechanisms acting on the conductor. Inthis thesis, cooling by means of convective heat transfer is studied based on wind tunnelexperimental measurements of three dierent conductor samples. Convection contributesto most of the cooling; however, it is aected by wind speed and direction. Two angle ofattacks were studied (40 and 90), where perpendicular ow was found to result in bettercooling. The location of boundary layer separation highly aects the surface distribution ofcooling, which is non-uniform. Oblique wind ow results in reduction in overall cooling dueto earlier boundary layer separation. Finally, the surface average convective heat transfercoecient correlates non-linearly with the Reynolds number, where higher wind speeds andlarger conductor diameters can lead to signicant improvements in cooling while keepingrelatively low current densities. The existing standards of IEEE and CIGRE were found tooverestimate the eect of convective cooling for the specic experimental cases. / Det är viktigt att hålla en kraftöverföringsledning inom nominella driftsförhållanden.Således leder en korrekt förutsägelse av ledarens termiska och elektriska beteende till en ökad tillförlitlighet och effektivitet. Under DLR-drift justeras nuvärdet baserat på omgivande väder och solförhållanden för att möjliggöra dynamisk belastning. Klassificeringsjusteringen tar hänsyn till de kylmekanismer som verkar på ledaren. I denna avhandling studeras kylning med hjälp av konvektiv värmeöverföring baserat på provning av vindtunnel av tre olika ledartyper. Konvektion bidrar till det mesta av kylningen. Det påverkas dock av vindhastighet och riktning. Två angreppsvinkelar studerades (40◦ och 90◦), där vinkelrätt flöde befanns resultera i bättre kylning. Placeringen av ytskiktseparationen har stor inverkan på ytfördelningen av kylning, vilken är ojämn. Skrå vindflöde resulterar i minskning av den totala kylningen på grund av tidigare separering av gränsskiktet. Slutligen korrelerar den ytvärdesöverföringskoefficienten för ytvärdet icke-linjärt med Reynolds-talet, där högre vindhastigheter och större ledardiametrar kan leda till signifikanta förbättringar i kylning samtidigt som relativt låga strömtäthet hålls. De befintliga standarderna för IEEE och CIGRE visade sig överskatta effekten av konvektiv kylning för de specifika experimentellafallen.

The power grid is a complex system that requires detailed planning and operation of the power sources. As renewable resources are increasing their share of the power mix, there are new criterion and aspects to take into account. Renewable resources such as wind and solar power are intermittent and challenge the planning and operation further. Simultaneously, the power demand increases and will continue to increase in the future. As the power resources and demand are changing in the power system, the power grid needs to adapt and be more flexible. A flexibility tool for the power system is Dynamic Rating which can dynamically increase the capacity in the power grid components depending on the environmental conditions. This can enable for higher transmission in overhead lines which facilitates the operation planning of power units. Dynamic rating can be applied to various power system components, but the focus in this project is Dynamic Line Rating (DLR). It is interesting to study the implementation of dynamic rating in the realtime market. The real-time market optimal power flow can be done in singleinterval or multi-interval. In this project, dynamic rating is implemented into multi-interval real-time market optimal power flow to investigate the effect on the generation costs. The results indicate that DLR can reduce the generation costs in power grids that are sometimes congested. / Kraftnätet är ett komplext system som kräver detaljerad planering och verksamhet av energikällor. Allt eftersom andelen förnybara energikällor ökar tillkommer nya aspekter att ta hänsyn till. Förnybara energikällor såsom vindkraft och solenergi har en mer ojämn produktion då de är beroende av vädret, vilket utmanar drift och planering av elproduktion mer än tidigare samtidigt som elbehovet ökar och kommer att fortsätta öka i framtiden. Det växande elbehovet och utökningen av förnybara energikällor kräver att elnätet kan anpassas och vara flexibelt. Ett sätt att öka flexibiliteten är att värdera kapaciten i transmissionsledningar dynamiskt (DLR) istället för statiskt där kapaciteten beräknas efter värsta tänkbara scenario. Dynamisk värdering kan därför möjliggöra högre kraftöverföring i ledningarna under gynsamma väderförhållanden vilket underlättar driften och planeringen av kraftkomponenterna. I detta examensarbete studeras dynamisk värdering av transmissionsledningar i realtidselmarknaden med flera intervall (MIRTM) där driftplaneringen optimeras så att driftkostnaderna minimeras under bivillor för kraftsystemet. Målet är att undersöka hur driftkostnaderna påverkas då bivillkoret för kraftflödet i transmissionsledningarna är mer flexibelt med DLR. Resultaten från detta projekt visar att DLR kan minska kostnaderna i elnät som är överbelastade.

Based on conventional static line rating method, the actual current carrying capability of overheadconductors cannot be judged. Due to continuous increment in electricity demand and the difficultiesassociated with new line constructions, the overhead lines are therefore required to be rated based on amethod that should establish their real-time capability in terms of electricity transmission. The methodused to determine the real-time ampacity of overhead conductors not only can enhance their transmissioncapacity but can also help in allowing excessive renewable generation in the electricity network. In thisdiploma work, the issues related to analyzing an impact of wind power on periodical loading of overheadline as well as finding its static and dynamic ampacities with line current are investigated in detail.Initially, in this project, the investigation related to finding a suitable location for the construction of a 60MW wind farm is taken on board. Thereafter, the wind park is integrated with a regional grid, owned byFortum Distribution AB. In addition to that, the electricity generated from the wind park is also calculatedin this project. Later on, the work is devoted to finding the static and dynamic line ratings for‘VL3’overhead conductor by using IEEE-738-2006 standard.Furthermore, the project also deals with finding the line current and making its comparison withmaximum capacity of overhead conductor (VL3) for loading it in such a way that no any violation of safeground clearance requirements is observed at all. Besides, the line current, knowing the conductortemperature when it transmits the required electricity in the presence of wind power generation is also animportant factor to be taken into consideration. Therefore, based on real-time ambient conditions withactual line loading and with the help of IEEE-738-2006 standard, the conductor temperature is alsocalculated in this project.At the end, an economic analysis is performed to evaluate the financial advantages related to applying thedynamic line ratings approach in place of traditional static line ratings technique across an overheadconductor (VL3) and to know how much beneficial it is to temporarily postpone the rebuilding and/orconstruction of a new transmission line. Furthermore, an economic analysis related to wind power systemis taken into consideration as well to get familiar with the costs related to building and connecting a 60MW wind farm with the regional grid.

Marknadsanalyser gjorda av Svenska kraftnät visar att elenergianvändningen i Sverige kommer att öka. Denna utveckling drivs på av bland annat omställningen till elektriska transporter och kan potentiellt leda till kapacitetsbrist i ledningar inom transmissions- och regionnät, framför allt i storstadsområden. För att kunna reducera kapacitetsbrist i en ledning finns det ett antal åtgärder, men hur dessa står sig mot varandra i ett tekniskt och ekonomiskt perspektiv är inte fastställt. Det är där denna rapport tar vid. Bland annat studeras Dynamic line rating (DLR) som en åtgärd för att reducera kapacitetsbristen i den studerade ledningen. DLR är en teknik som används för att justera den maximalt tillåtna överföringskapaciteten i en ledning baserat på ett antal parametrar. Beräkningarna för att bestämma maximalt tillåtna överföringskapaciteten i ledningen gjordes på två olika sätt detta för att undersöka om de var likvärdiga. Det visade sig att de stämde relativt bra överens, dock med en offset. Den potentiella överlasten skulle inträffa under 3379 timmar under ett år, men enbart om en specifik transformator gick sönder. Medeltiden till felet visade sig vara 173 år utan att några åtgärder applicerades. För att nå upp till 100 % tillgänglighet på ledningen, utan åtgärder, skulle det behöva köpas flexibilitetstjänster motsvarande 82150 MWh (Megawattimmar) under det studerade året.  Även den ekonomiska kostnaden för att köpa upp- eller nedreglerande tjänster studerades. Rapporten visar att det för den studerade ledningen var till fördel att investera i DLR vid ett flexibilitetsbehov på 1,2 GWh/år. Från resultatet utformades ett förslag på lämplig ordning för att nyttja de olika åtgärdena samt förslag på vidareutveckling av arbetet. Slutsatsen är att åtgärderna har sina för- och nackdelar, men att det inte går att säga att någon åtgärd är bättre än någon annan. Detta gäller inom samtliga områden som studerades. / Market analyzes made by Svenska kraftnät show that electricity use in Sweden will increase. This development is driven by, among other things, the transition to electric transport and can potentially lead to a lack of capacity in lines within backbone and regional networks, especially in metropolitan areas. In order to be able to reduce capacity shortages in a transmission line, there are a number of measures, but how these stand against each other in a technical and economic perspective has not been determined. That's what this report tries to answer.  Among other things, Dynamic line rating (DLR) is studied as a measure to reduce the capacity shortage in the studied transmission line. DLR is a technology used to adjust the maximum allowable transmission capacity in a line based on a number of parameters. The calculations to determine the maximum allowable transmission capacity in the transmission line were made in two different ways to examine whether they were equivalent. It turned out that they matched relatively well, though with an offset. The potential overload would occur during 3379 hours in a year, but only if a specific transformer broke down. The mean time to failure turned out to be 173 years without any measures being applied. In order to achieve up to 100 % availability on the line, without measures, it would be necessary to purchase flexibility services corresponding to 82150 MWh (Megawatt hours) during the year studied. The financial cost of buying up or down regulation services was also studied. The report shows that it was advantageous for the studied transmission line to invest in DLR at a flexibility requirement of 1.2 GWh / year. From the results, a proposal was made for an appropriate arrangement for using the various measures as well as proposals for further development of the work. The conclusion is that the measures have their advantages and disadvantages, but it is not possible to say that one measure is better than another. This applies to all areas studied.

The use of electricity from Distributed Energy Resources like wind and solar powerwill impact the performance of the electricity network and this sets a limit to theamount of such renewables that can be connected. Investment in energy storage andcommunication technologies enables more renewables by operating the networkcloser to its limits. Electricity networks using such novel techniques are referred toas “Smart Grids”. Under favourable conditions the use of these techniques is analternative to traditional network planning like replacement of transformers orconstruction of new power line.The Hosting Capacity is an objective metric to determine the limit of an electricitynetwork to integrate new consumption or production. The goal is to create greatercomparability and transparency, thereby improving the factual base of discussionsbetween network operators and owners of Distributed Energy Resources on thequantity and type of generation that can be connected to a network. This thesisextends the Hosting Capacity method to the application of storage and curtailmentand develops additional metrics such as the Hosting Capacity Coefficient.The research shows how the different intermittency of renewables and consumptionaffect the Hosting Capacity. Several case studies using real production andconsumption measurements are presented. Focus is on how the permitted amountof renewables can be extended by means of storage, curtailment and advanceddistributed protection and control schemes. / Användningen av el från förnyelsebara energikällor som vind och sol kommer att påverka elnätet, som sätter en gräns för hur mycket distribuerad energiproduktion som kan anslutas. Investeringar i storskalig energilager och användning av modern kommunikationsteknologi gör det möjligt att öka andelen förnyelsebarenergi genom att nätet kan drivas närmare sina gränser. Elnät med sådana nya tekniker kallas ofta för ”Smarta Elnät". Implementering av sådana smarta elnät kan vara ett alternativ till traditionell nätplanering och åtgärder som utbyte av transformatorer eller konstruktion av nya kraftledningen.Nätets acceptansgräns är ett objektivt mått för att bestämma gränsen för nätets förmåga att integrera ny förbrukning eller produktion. Målet är att skapa större transparens och bidra till ett bättre faktaunderlag i diskussioner mellan nätoperatörer och ägare av distribuerade energiresurser. Denna avhandling utökar acceptansgränsmetoden för tillämpning med energilager och produktions nedstyrning och utvecklar ytterligare begrepp så som acceptansgränsen koefficienten.Forskningen visar hur varierbarheten hos olika förnyelsebara energikällor samverkar med förbrukningen och påverkar nätets acceptansgräns. Flera fallstudier från verkliga elnät och med uppmätt produktion och konsumtion presenteras. Fokus är på hur den tillåtna mängden förnyelsebara energikällor kan ökas med hjälp av energilagring, kontrollerad produktionsnedstyrning och med avancerad distribuerade skydd och kontroll applikationer. / Nicholas Etherden works at STRI AB (www.stri.se) in Gothenburg, Sweden. When he is not pursuing his half-time PhD studies he works as a specialist consultant in the field of Power Utility Automation, specialising on the IEC 61850 standard for power utility automation (today widely used in substations as well as some wind parks, hydro plants and DER and Smart Grid applications such as vehicle-to-grid integration). The author of this thesis received his Master of Science in Engineering Physics from Uppsala University 2000. Side tracks during his engineering studies included studies in theoretical philosophy, chemistry, ecology and environmental sciences as well as chairing the Swedish student committee of the Pugwash Conferences on Science and Worlds Affairs and later board member of the International Network of Engineers and of Scientists for Global Responsibility (INES) and chair of Swedish Scientists and Engineers Against Nuclear Arms. He has been a trainee at ABB in Västerås Sweden and spent six years as developer and team leader for the application development of a new relay protection family (ABB IED 670 series). In parallel to his professional work he studied power system engineering at Mälardalens University and travelled to all continents of the world. Since 2008 he is responsible for the STRI IEC 61850 Independent Interoperability Laboratory and a member of IEC Technical Committee 57 working group 10 "Power system communication and associated data models” and UCA/IEC 61850 User group testing subcommittee. He is co-author of IEC 61850-1 and main contributor to “Technical Report on Functional Test of IEC 61850 systems” and has held over 25 hands-on courses around the world on IEC 61850 “Communication networks and systems for power utility automation”. / SmartGrid Energilager

Dynamic Rating (DR) is usually associated with unlocking the capacity of power lines and transformers using available information on weather conditions. Our studies show that Dynamic Rating is a broad concept that requires further study and development. The capacity of the majority of power devices is highly dependent on the heat transfer properties of the materials which the devices are made of. To ensure correct power limits of the equipment, one must take into consideration not only the power load, but also ambient conditions, such as: temperature, wind speed, wind direction, solar irradiation, humidity, pressure, radiation into the atmosphere and magnetic losses. Dynamic rating is created as an alternative to standard constant rating that is designed with reference to extreme weather and load conditions. Some areas are more likely than others to experience extreme weather conditions, which have a chance of occurring only a few days per year for short periods of time. Such a distribution of weather parameters gives an opportunity to embed existing material properties of the power equipment and achieve a better utilization of the grid. The following thesis is divided into two simultaneous topics: Dynamic line rating and Dynamic transformer rating. The division is motivated by the importance of analysing the operation of the above-mentioned parts of the power network in greater detail. Power lines and transformers play a significant part in grid planning and have a potential to result in economic benefits when used with DR. The main focus of the doctoral project "Dynamic rating of power lines and transformers for wind energy integration" is on exploring potential ways to connect power generated from wind to the grid with the help of dynamic rating technologies. Therefore, great focus of the work lies on the analysis of DR connection of variable energy sources such as wind farms. The thesis presents the comparison of different line rating methods and proposes a new way of their classification. Evaluation of dynamic line rating application has shown the possibility to expand the power grid with additional capacity from wind power generation. Literature analysis and detailed evaluation of the conductor heat balance models have led to experimental evaluation of the convective cooling effect. The dynamic transformer rating application has shown a possibility to decrease the size of the power transformer without shortcoming in component availability. / <p>QC 20180423</p> / Dynamic Rating for Wind Power