Pienjänniteverkon sulakesuojauksen suunnittelun automatisointi

The planning of electricity networks is time consuming work. The plans may concern huge areas and attention must be paid to the details. Even the smaller plans include various repetitive tasks, which combined increase the time to finish the plan. To get rid of some of the repetitive manual work and to speed up the process, the planners have different instructions and tables. However, the most time savings could be achieved with an automatic planning tool. The goal of this thesis is to develop an application to plan the fuses of a given low voltage network automatically. To reach the goal, the fuse planning process is examined thoroughly. The studied material includes low voltage networks and fuses before moving on to the fuse protection planning process. The fuse protection was studied from the national standards and with professional planners. The standards were combined with inputs of the planners to create the solution. As a result, the automatic fuse planning application was successfully developed with the essential features. However, some more advanced topics were left for future development, which will continue. A result network with fuses is introduced in chapter 5.Sähköverkkojen suunnittelu on aikaa vievää työtä. Suunnitelmat saattavat koskea valtavia alueita ja yksityiskohdat vaativat tarkkuutta. Myös pienemmät verkkosuunnitelmat sisältävät toistuvaa käsin tehtävää työtä. Suunnittelijoilla on käytössään erilaisia ohjeita ja taulukoita, joiden avulla päästään eroon joistain toistuvista tehtävistä sekä säästetään aikaa. Suurimmat ajansäästöt voidaan kuitenkin saavuttaa automaattisella suunnittelutyökalulla. Tämän työn tavoitteena oli kehittää työkalu, joka suunnittelee annetun pienjänniteverkon sulakkeet automaattisesti. Sulakesuojauksen suunnitteluprosessia tutkittiin huolellisesti, jotta tavoite saavutettaisiin. Tämä työ sisältää katsaukset pienjänniteverkkoon sekä sulakkeisiin ennen sulakesuojauksen suunnitteluun siirtymistä. Sulakesuojausta tutkittiin sekä kansallisista standardeista että sähköverkkojen suunnittelijoiden kanssa. Standardien sekä suunnittelijoiden ohjeet yhdistettiin, minkä pohjalta lopputulos syntyi. Työn lopputuloksena kehitettiin onnistuneesti työkalu sulakesuojauksen automaattista suunnittelua varten. Työkalusta löytyvät olennaisimmat ominaisuudet, mutta joidenkin haastavampien aiheiden käsittely jäi vielä tulevaisuuteen. Kehitystyö kuitenkin jatkuu tulevaisuudessa. Suunnittelutyökalun tuloksena on esitetty verkko sulakkeineen luvussa 5

Low-Cost, Robust, Threat-Aware Wireless Sensor Network for Assuring the Nation's Energy Infrastructure

Eaton, in partnership with Oak Ridge National Laboratory and the Electric Power Research Institute (EPRI) has completed a project that applies a combination of wireless sensor network (WSN) technology, anticipatory theory, and a near-term value proposition based on diagnostics and process uptime to ensure the security and reliability of critical electrical power infrastructure. Representatives of several Eaton business units have been engaged to ensure a viable commercialization plan. Tennessee Valley Authority (TVA), American Electric Power (AEP), PEPCO, and Commonwealth Edison were recruited as partners to confirm and refine the requirements definition from the perspective of the utilities that actually operate the facilities to be protected. Those utilities have cooperated with on-site field tests as the project proceeds. Accomplishments of this project included: (1) the design, modeling, and simulation of the anticipatory wireless sensor network (A-WSN) that will be used to gather field information for the anticipatory application, (2) the design and implementation of hardware and software prototypes for laboratory and field experimentation, (3) stack and application integration, (4) develop installation and test plan, and (5) refinement of the commercialization plan

HVAC Transmission Systems for Offshore Wind Farms: Optimal Reactive Power Compensation

Wind power is one of the cheapest and most developed sources of clean energy, and it will be a key contributing factor to the decarbonisation of the electrical grid. Offshore wind power has many advantages over its on-land counterpart, namely a higher and more reliable power output and reduced interference with the environment and other economic activities. However, offshore wind requires higher upfront investments and presents many technical challenges. One of the most relevant issues is finding cost-effective solutions to connect offshore wind power plants to the electrical grid. Several alternatives have been proposed and currently HVAC and HVDC are the predominant technologies, the latter being the go-to option for plants far offshore. However, recent advances in HVAC cables and the success of projects incorporating mid-cable reactors for compensation purposes suggest that the applicability of HVAC might be extended to longer distances than what was previously believed. The aim of this thesis is to analyse different HVAC transmission configurations, including midcable reactors and variable-speed wind turbines, which can provide part of the reactive power. The optimal configuration and operation for different distances to shore is derived, and the cost savings are presentedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.b - Per a 2030, ampliar la infraestructura i millorar la tecnologia per tal d’oferir serveis d’energia moderns i sos­tenibles per a tots els països en desenvolupament, en particular els països menys avançats, els petits estats insulars en desenvolupament i els països en desenvolupament sense litoral, d’acord amb els programes de suport respectiu

Communication Infrastructures for Distributed Control of Power Distribution Networks

Accepted versio

On possibilities of smart meters switching at low voltage level for emergency grid management

Smart Meter (SM) is an advanced remotely readable energy meter with two-way communication capability which measures the electrical energy in real-time or near-real-time and securely sends data to Distribution System Operator (DSO). A smart metering system is an application of SMs on a larger scale, i.e. the application of a general principle on a system rather than on individual appliance. The European Commission (EC) has included ten common minimum functional requirements for electricity smart metering systems. One functionality requirement among these functional requirements is that the SM should allow remote ON/OFF switch to control the supply. Some DSOs who have installed remote ON/OFF switch are currently applying this technique for customers typically one by one when customers are changing addresses, or when contracts are terminated, or have defaulted on their payments. The switching functionalities of the SMs could be used for multiple customers, thereby opening up new possibilities for emergency electrical grid management by excluding prioritized customers. There is an interest to investigate if the multiple SMs switching might have some impacts on the Power Quality (PQ) of the electrical grid and also the challenges in implementing this technique on the existing smart metering system during emergency situation. In this thesis work, three field tests have been performed on multiple SMs switching focusing on the impact of the SMs switching on the PQ of the grid. A risk analysis was carried out before conducting the field tests. The PQ measurements were done by Power Quality Meters (PQMs) during the multiple SMs switching. Voltage variations and PQ events were recorded in the PQMs. Waveform data of the PQ events were recorded at 12.8 kHz sampling frequency. The test results are then evaluated based on PQ standards. Moreover, performance of the existing smart metering system was investigated during the multiple SMs switching to identify the challenges and possibilities of using multiple SMs switching. The analysis of the test results show that there were no other PQ events or voltage variations except some transient events which were recorded at some customer level during the reconnection of the SMs. However, the duration of the transient events was only fractions of a millisecond and deviation of the voltage transients were below +/-50% except for few transient events which have deviations of more than +/- 50% but less than +/-60%. This type of transient events may not be able to create damage to sensitive customers’ loads. The multiple SMs switching may not have impact on the PQ if the number of customers is low. However, SMs switching for large number of customers might have impact on the PQ which needs to be investigated. Moreover, the performance of the existing smart metering system during multiple SMs switching shows some limitations on implementing the switching technique for large scale of customers. The identified limitations are e.g., long time requirement for SMs switching and errors in the real-time status update report during SMs switching. Furthermore, the findings show that more research is needed to identify required functions for future smart metering system to implement multiple SMs switching during emergency grid management

PCA-enhanced methodology for the identification of partial discharge locations

Partial discharge (PD) that occurs due to insulation breakdown is a precursor to plant failure. PD emits electromagnetic pulses which radiate through space and can be detected using appropriate sensing devices. This paper proposed an enhanced radiolocation technique to locate PD. This approach depends on sensing the radio frequency spectrum and the extraction of PD location features from PD signals. We hypothesize that the statistical characterization of the received PD signals generates many features that represent distinct PD locations within a substation. It is assumed that the waveform of the received signal is altered due to attenuation and distortion during propagation. A methodology for the identification of PD locations based on extracted signal features has been developed using a fingerprint matching algorithm. First, the original extracted signal features are used as inputs to the algorithm. Secondly, Principal Component Analysis (PCA) is used to improve PD localization accuracy by transforming the original extracted features into s new informative feature subspace (principal components) with reduced dimensionality. The few selected PCs are then used as inputs into the algorithm to develop a new PD localization model. This work has established that PCA can provide robust PC representative features with spatially distinctive patterns, a prerequisite for a good fingerprinting localization model. The results indicate that the location of a discharge can be determined from the selected PCs with improved localization accuracy compared to using the original extracted PD features directly

Flexibility of Electric Power Systems by Network Planning and Service Provision: Challenges for Energy Transition

In recent years, the electric power system is meeting a radical evolution due to the increasing penetration of Renewable Energy Sources (RESs). These have a relevant impact on most of the applications concerning the electrical network, such as the electricity markets, regulation services provision and the grid management and protection. However, the deep RESs deployment is the answer that countries all over the world are pursuing to fight climate change according to the Sustainable Development Goals (SDGs) adopted by the United Nations (UN). This evolution requires a great development of the network, that has to host a large quantity of new RESs, and the establishment of new strategies to deal with new challenges. More and more reserves for regulation services are pursued by units that couldn’t provide dispatching services until now, namely small-sized plants and RESs, but also load and storage systems. The demand has become increasingly more active since it has made possible a contribution to instability issues by varying their power profile for a certain amount of time without compromising the final user’s comfort, which means being flexible. As a result, a huge amount of new generation units and load units have started to provide dispatching services by participating to the electricity markets. This condition has led to the need of the improvement of the communication systems among all the actors in the process of power transmission alongside grid balancing, including the Transmission System Operator (TSO), the Distribution System Operators (DSOs), generation, load units and other data aggregators. The observability of the system is essential to forecast load and generation profiles in order to provide a suitable balancing service and to guarantee the reliability, safety and power quality of the electrical network through state estimation methods which are going to be widely used in modern systems. Observability is also important in making decisions for the planning of the network development by giving access to information about the grid operating conditions. Therefore it suggests how to focus the efforts to improve the electric power system performance according to the objectives established to reduce the impact of fossil fuels in the climate change. In sight of this, it can be concluded that the key to deal with climate change is a suitable coordination of such factors: the development of the network, the arrangement of flexibility resources and the communication systems improvement. During the Doctorate (Ph.D.), the author has worked on several research projects related to the topic of the evolution of the electric system. The project are listed in the Appendices. This thesis gathers the work done by underlining the importance of the three factors mentioned before in the context of the power system evolution. The developed applications will be presented as particular approaches that can be applied to a general power system and take place in one or more aspects of the ecological transition. In Chapter 1, the UN strategies to deal with climate change are introduced as well as the main consequences they led to and the new needs of the electric system are described. An introduction to regulation services and their purpose is given. In Chapter 2 the Italian context, as part of the European and Global plan to reduce emissions, is described. The main tools used by the Italian TSO to plan the network development are introduced and the study case of the network of Sicily is explained in the contest of the project ”Assessments of Battery Energy Storage Systems Potential in Improving the Working Condition of the Grid of Sicily”. As a continuation of this work, the method developed in the project ”Optimal Storage Allocation for Transmission Network Development Planning” is applied to the Sicilian network model and its possible contribution to network infrastructure planning is described. In Chapter 3 the impact that the installation of several RESs have on the grid stability is described. The consequent evolution process of the electricity market in order to cope with the increased need of regulation services is explained. In such context, pilot projects have been established by the TSO to encourage research of flexibility resources with reference to the projects concerning regulation service provision from loads and RESs. In Chapter 4, in project ”Flexibility Evaluation of an Aggregate of Thermal Load Units”, a definition of flexibility resources is given and a flexibility analysis of aggregates of thermal loads intended for domestic hot water heating, such as domestic electric water heaters or heat pumps, has been carried out during the research activity. A Monte Carlo approach is adopted for the methodology applied to the study case of Italy and Sicily. Chapter 5 describes and presents the results of the project ”Model Predictive Control for frequency regulation services provision” where the fast frequency reserve service is explored according to the related pilot project by using Model Predictive Control (MPC) based techniques applied on systems with RESs and Battery Energy Storage Systems (BESSs). Such service is meant to replace the beneficial effect of inertia from the traditional generating units which is progressively decreasing because of the implementation of RESs units in the power system. The decrease of inertia leads to more significant frequency variations after fault events that must be solved within extremely high speed actions, even faster than primary frequency regulation service. To complete the thesis, the Conclusions are presented together with some last comments. Finally, the publications produced during the Ph.D. and the projects to which contribution was given, collaborations and attended courses are listed, while references cited in this thesis end the dissertation

Large-Scale Photovoltaic Solar Implementation: Montanan Stakeholder Opportunities and Challenges

Large-scale photovoltaic (PV) solar projects were operationalized in the 1990s resulting in a plethora of studies focusing on environmental, economic, technological, and policy studies. Minimal research investigates the similarities and differences between conveners using PV solar technology. This case study evaluates stakeholder perceptions regarding project management, project design, and external factors influencing the success of large-scale PV solar projects convened by a qualifying facility, regional utility company, and electric co-operative in Montana. Respondents revealed concepts were similar across conveners; yet, emphasized unique implications for each convener. The results indicated the importance for all conveners to incorporate marketing strategies, local interests and goals, aesthetic considerations, and creative partnerships to maximize the likelihood of success for large-scale PV solar projects. No singular type of convener in Montana provides the greatest opportunities; rather each convener is fulfilling a niche taking advantage of specific project management, project design, and external factors applicable to their organizational structure