The aim of this study is evaluation of using multi-dimensional statistical analyses methods as a tool for simulations of reliability of distribution network. Prefered methods are a cluster analysis (CLU) and a principal component analysis (PCA). CLU is used for a division of objects on the basis of their signs and a calculation of the distance between objects into groups whose characteristics should be similar. The readout can reveal a secret structure in data. PCA is used for a location of a structure in signs of multi-dimensional matrix data. Signs present separate quantities describing the given object. PCA uses a dissolution of a primary matrix data to structural and noise matrix data. It concerns the transformation of primary matrix data into new grid system of principal components. New conversion data are called a score. Principal components generating orthogonal system of new position. Distribution network from the aspect of reliability can be characterized by a number of new statistical quantities. Reliability indicators might be: interruption numbers, interruption time. Integral reliability indicators might be: system average interruption frequency index (SAIFI) and system average interruption duration index (SAIDI). In conclusion, there is a comparison of performed SAIFI simulation according to negatively binomial division and provided values from a distribution company. It is performed a test at description of sign dependences and outlet divisions.

En la actualidad, la falta de planificación y control que existe en el desarrollo de proyectos de abastecimiento de agua potable es un factor determinante en la presencia de deficiencias en el funcionamiento de las redes de distribución en términos de continuidad y calidad de servicio. Esta investigación, haciendo uso del modelamiento hidráulico, busca evaluar el comportamiento de la red de distribución de agua de la localidad de Paucartambo-Cusco, con el fin de proponer soluciones y mejoras que ayuden a controlar y disminuir las deficiencias tanto actuales como futuras que pudieran presentarse. Primeramente, se planteó la modelación de la red en estado actual, comportamiento real, verificando los distintos factores de diseño, así como la consideración del análisis de agua no facturada (ANF). En este se encontró que las deficiencias del parque de medidores correspondientes a las conexiones activas generan un elevado porcentaje de ANF, lo que afecta el funcionamiento de la red en términos de continuidad y servicio. Para evaluar su influencia en una red futura se realizó un balance oferta-demanda. Bajo esta premisa se presentó una propuesta de red futura en un escenario donde se controla el porcentaje de ANF mediante la implementación de planes y acciones de manejo, logrando reducir la dotación existente (302.38 lt/hab/dia) hasta valores más acordes con el R.N.E (180 lt/hab/dia) significando una disminución del porcentaje de ANF de 68% hasta 40.47% aproximadamente, lo que garantiza un funcionamiento más óptimo tanto hidráulica como económicamente frente a un escenario que no considere el análisis de ANF. / At present, the lack of planning and control that exists in the development of potable water supply projects is a determining factor in the presence of deficiencies in the operation of distribution networks in terms of continuity and quality of service. This research, using hydraulic modeling, seeks to evaluate the behavior of the water distribution network of the town of Paucartambo-Cusco, in order to propose solutions and improvements that help control and reduce both current and future deficiencies that could introduce oneself. First, the modeling of the network in the current state, real behavior, verifying the different design factors, as well as the consideration of the non-invoiced water analysis (ANF) was considered. In this, it was found that the deficiencies of the meter stock corresponding to the active connections generate a high percentage of ANF, which affects the operation of the network in terms of continuity and service. To assess its influence on a future network, an offer-demand balance was made. Under this premise, a proposal for a future network was presented in a scenario where the percentage of ANF is controlled through the implementation of management plans and actions, reducing the existing endowment (302.38 lt / hab / day) to values ​​more in line with the RNE (180 lt / hab / day) meaning a decrease in the percentage of ANF from 68% to approximately 40.47%, which guarantees a more optimal operation both hydraulically and economically compared to a scenario that does not consider the ANF analysis. / Tesis

[pt] A inclusão da gestão tributária no planejamento da cadeia de distribuição é fator diferenciador, especialmente no Brasil, onde os Estados têm políticas tributárias díspares e uma postura agressiva para atrair empresas. A inclusão das preocupações tributárias quando da definição de redes de distribuição, nomeadamente na escolha de localização de infraestruturas, é, no entanto, ainda feito de forma empírica. Para avaliar o impacto dos incentivos fiscais no desenho da rede de distribuição, foi proposto um modelo de programação linear inteira mista (PLIM), incluindo como parâmetros e restrições as oportunidades criadas pela política tributária. O objetivo é definir o número e o local de centros de distribuição, bem como a alocação de clientes a cada centro, tal que o custo logístico seja minimizado (custo de frete, custo de construção, operação e manutenção dos centros de distribuição e custos tributários divididos entre mudanças de alíquotas de produtos e de fretes ao realizar cada transferência de localização). O modelo é aplicado a uma empresa brasileira que comercializa produtos químicos e foi instalada em um local distante do ponto de entrega final dos produtos, devido à inserção em um programa de incentivos fiscais, sem a adoção de nenhum modelo de localização para avaliação desta estratégia. A solução gerada pelo modelo obteve menores custos totais para o novo desenho de rede em comparação com a rede atual. / [en] Including tax management in supply chain planning is a profitable differentiating factor, especially in Brazil, where each State exhibits its own tax policy. Some studies have been conducted taking into account the tax issues in the logistics network design, however this thesis takes into account the tax incentives offered by some Brazilian states to attract business. To assess the impact of tax incentives in the distribution network design, it proposed a model for locating distribution centers based on Mixed Integer Linear Programming (MILP) that includes parameters and factors related to the restrictions and opportunities created by Brazilian tax policies. The model is applied to a Brazilian company that sells chemical products. This company is installed in a location away from the end point of delivery of the products due to insertion into a tax incentive program, without adopting any location model for evaluating the strategy. The goal is to determine the actual advantages of a reduction in tax rates offset an increase in logistics transportation costs. The solution determined whether the construction of a new distribution center is beneficial, if the results generated by the model had lower total costs for the new network design compared to the current network.

One of EU’s actions against climate change is to meet 20% of our energy needs from renewable resources. Given that the renewable resources are becoming more economical to extract electricity from, this will result in that more and more distributed generation (DG) will be connected to power distribution. The increasing share of DG in the electricity networks implies both increased costs and benefits for distribution system operators (DSOs), customers and DG producers. How the costs and benefits will be allocated among the actors will depend on the established regulation. Distribution networks are traditionally not designed to accommodate generation. Hence, increasing DG penetration is causing profound changes for DSOs in planning, operation and maintenance of distribution networks. Due to the unbundling between DSOs and electricity production, DSOs can not determine either the location or the size of DG. This new power distribution environment brings new challenges for the DSOs and the electric power system regulator. The DSOs are obliged to enable connection of DG meanwhile fulfilling requirements on power quality and adequate reliability. Moreover, regulatory implications can make potential DG less attractive. Therefore regulation should be able to send out incentives for the DSOs to efficiently plan the network to accommodate the increasing levels of DG. To analyze the effects of regulatory polices on network investments, risk analysis methods for integrating the DG considering uncertainties are therefore needed. In this work, regulation impact on network planning methods and network tariff designs in unbundled electricity network is firstly analyzed in order to formulate a realistic long-term network planning model considering DG. Photovoltaic (PV) power and wind power plants are used to demonstrate DG. Secondly, this work develops a deterministic model for low-voltage (LV) networks mainly considering PV connections which is based on the worst-case scenario. Dimension the network using worst-case scenario is the convention in the long-term electricity distribution network planning for the reliability and security reason. This model is then further developed into a probabilistic model in order to consider the uncertainties from DG production and load. Therefore more realistic operation conditions are considered and probabilistic constrains on voltage variation can be applied. Thirdly, this work develops a distribution medium-voltage (MV) network planning model considering wind power plant connections. The model obtains the optimal network expansion and reinforcement plan of the target network considering the uncertainties from DG production and load. The model is flexible to modify the constraints. The technical constraints are respected in any scenario and violated in few scenarios are implemented into the model separately. In LV networks only PV connections are demonstrated and in MV networks only wind power connections are demonstrated. The planning model for LV networks is proposed as a practical guideline for PV connections. It has been shown that it is simple to be implemented and flexible to adjust the planning constraints. The proposed planning model for MV networks takes reinforcement on existing lines, new connection lines to DG, alternatives for conductor sizes and substation upgrade into account, and considers non-linear power flow constraints as an iterative linear optimization process. The planning model applies conservative limits and probabilistic limits for increasing utilization of the network, and the different results are compared in case studies. The model’s efficiency, flexibility and accuracy in long-term distribution network planning problems are shown in the case studies. / <p>QC 20140217</p> / Elforsk Risknanlys II

It is foreseeable that device-to-device (D2D) communication will become a standard feature in the future, for the reason that it offloads the data traffic from network infrastructures to user devices. Recent researches prove that delivering delay-tolerant contents through content delivery network (CDN) by D2D helps network operators increase spectral and energy efficiency. However, protecting the private information of mobile users in D2D assistant CDN is the primary concern, which directly affects the willingness of mobile users to share their resources with others. In this thesis, we proposed a privacy concerned top layer system for selecting the sub-optimal set of mobile nodes as initial mobile content provider (MCP) for content delivery in any general D2D communications, which implies that our proposed system does not rely on private user information such as location, affinity, and personal preferences. We model the initial content carrier set problem as an incentive maximization problem to optimize the rewards for network operators and content providers. Then, we utilized the Markov random field (MRF) theory to build a probabilistic graphical model to make an inference on the observation of delivered contents. Furthermore, we proposed a greedy algorithm to solve the non-linear binary integer programming (NLBIP) problem for selecting the optimal initial content carrier set. The evaluations of the proposed system are based on both a simulated dataset and a real-world collected dataset corresponding to the off-line and on-line scenarios.

Nowadays, a high penetration level of distributed energy resources (DERs), such as renewables, energy storage, and electric vehicles, are integrated into modern electric power grids, especially power distribution sections, through inverter-based interfaces. Depending on the interfacing technologies and capacities of different DERs, the power distribution networks with inverter-based DERs feature different characteristics, which motivates this dissertation to investigate the modeling, design, and control of heterogeneous inverter-based power distribution networks. First, an example of a DER power distribution network, a PV system, is studied and an optimal design framework for PV systems is proposed considering two objectives, levelized cost of energy (LCOE) and power density (PD). Second, to further improve the performance of the inverter-based distribution networks, the harmonic characteristics of a generic grid-interactive inverter is investigated. A holistic mathematical harmonic state space (M-HSS) model of a grid-interactive inverter is derived to calculate each order of harmonics of grid-connected current. Moreover, to further reduce the computation burden caused by repetitive usage of the mathematical HSS model during the optimal design process, a data-driven HSS (D-HSS) modeling method is proposed by incorporating the data-driven techniques into the aforementioned M-HSS modeling. Based on the M- and D-HSS models, an effective optimal design framework is proposed to determine the closed-loop inverter system parameters. Furthermore, due to the increasing deployment of power electronic devices and nonlinear loads, power grids in the distribution network typically present certain degrees of low and/or high order harmonics. Thus, a harmonic compensation control (HCC) scheme is proposed to ensure that the inverter-based distribution network could provide high-quality grid current injection under distorted grid voltage conditions. Additionally, an energy-stored quasi-Z source converter (qZSC) based interlink converter is proposed for hybrid AC/DC microgrids in the distribution networks. The proposed system not only interlinks both AC and DC sub-microgrids but also incorporates energy storage. The operating principle, operating states as well as control schemes are presented in detail. Finally, another DER power distribution network, a medium voltage DC (MVDC) distribution network, is investigated in the study. First, the dissertation proposes an effective fault management scheme for MVDC networks, which includes a virtual-impedance-based fault current limiter (VI-FCL) on the DC side and a positive-negative-sequence (PNS) control scheme on the AC side. Finally, another DER power distribution network, a medium voltage DC (MVDC) distribution network, is investigated in the study. First, the dissertation proposes an effective fault management scheme for MVDC networks, which includes a virtualimpedance-based fault current limiter (VI-FCL) on the DC side and a positive-negativesequence (PNS) control scheme on the AC side. Then, a detailed 2ω mathematical model of the MVDC network under unbalanced AC voltage conditions is derived to investigate how the 2ω ripple propagates across the network and the corresponding control scheme is investigated to mitigate the 2ω ripple. / Electrical and Computer Engineering

yes / The current electricity grid suffers from numerous challenges due to the lack of an effective energy management strategy that is able to match the generated power to the load demand. This problem becomes more pronounced with microgrids, where the variability of the load is obvious and the generation is mostly coming from renewables, as it depends on the usage of distributed energy sources. Building a smart microgrid would be much more economically feasible than converting the large electricity grid into a smart grid, as it would require huge investments in replacing legacy equipment with smart equipment. In this paper, application of Internet of Things (IoT) technology in different parts of the microgrid is carried out to achieve an effective IoT architecture in addition to proposing the Internet-of-Asset (IoA) concept that will be able to convert any legacy asset into a smart IoT-ready one. This will allow the effective connection of all assets to a cloud-based IoT. The role of which is to perform computations and big data analysis on the collected data from across the smart microgrid to send effective energy management and control commands to different controllers. Then the IoT cloud will send control actions to solve microgrid's technical issues such as solving energy mismatch problem by setting prediction models, increasing power quality by the effective commitment of DERs and eliminating load shedding by turning off only unnecessary loads so consumers won't suffer from power outages. The benefits of using IoT on various parts within the microgrid are also addressed.

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