Review of trends and targets of complex systems for power system optimization

Optimization systems (OSs) allow operators of electrical power systems (PS) to optimally operate PSs and to also create optimal PS development plans. The inclusion of OSs in the PS is a big trend nowadays, and the demand for PS optimization tools and PS-OSs experts is growing. The aim of this review is to define the current dynamics and trends in PS optimization research and to present several papers that clearly and comprehensively describe PS OSs with characteristics corresponding to the identified current main trends in this research area. The current dynamics and trends of the research area were defined on the basis of the results of an analysis of the database of 255 PS-OS-presenting papers published from December 2015 to July 2019. Eleven main characteristics of the current PS OSs were identified. The results of the statistical analyses give four characteristics of PS OSs which are currently the most frequently presented in research papers: OSs for minimizing the price of electricity/OSs reducing PS operation costs, OSs for optimizing the operation of renewable energy sources, OSs for regulating the power consumption during the optimization process, and OSs for regulating the energy storage systems operation during the optimization process. Finally, individual identified characteristics of the current PS OSs are briefly described. In the analysis, all PS OSs presented in the observed time period were analyzed regardless of the part of the PS for which the operation was optimized by the PS OS, the voltage level of the optimized PS part, or the optimization goal of the PS OS.Web of Science135art. no. 107

Design of model of smart grid.

Import 22/07/2015Náplní této bakalářské práce je navrhnout a vytvořit fyzický model, maketu chytré elektrizační sítě. Tento model je navržen tak, aby vizuálně zobrazil tok energií ve vedeních distribuční soustavy vybavené telekomunikačními a datovými sítěmi pro moderní řízení sítě. Vytvořená síť obsahuje všechny prvky, se kterými je uvažováno v teoretických modelech chytrých distribučních sítí. Na modelu najdeme distribuované elektrárny, lokální mikrosíť vytvořenou z vilové čtvrti, sídliště představující odběr střední velikosti a továrnu představující velkoodběr. Dále na modelu najdeme centrální akumulátor pro řízení výkonové rovnováhy sítě a elektrické vedení napojení na napájecí nadřazenou elektrizační soustavu. Vizualizace modelu je provedena tak, aby byl model maximálně názorný a bylo ho možné použít jako výukový materiál pro prvotní seznámení se s fungováním a topologií chytré sítě. Vizuální prvky modelu jsou ztvárněny LED diodami a malými DC motorky, vše je řízeno pomocí řídící desky elektroniky přímo vytvořené pro řízení tohoto modelu. Mikroprocesor řídící desky je naprogramován tak, že model pracuje v několika módech lišících se momentálním výkonem distribuovaných elektráren. Textová část bakalářské práce obsahuje v první části teoretické pojednání o chytrých sítích a v části druhé popis vytvořeného modelu, popis jeho funkčních stavů, schémata plošných spojů použitých na modelu, fotografie detailů jednotlivých částí a obrázky ze samotného návrhu částí modelu.The aim of this bachelor thesis is to design and create a physical model of smart electricity grid. This model is designed to visually show the energy flow in the lines of distribution grid which is equipped with telecommunication and data networks for advanced network management. A network contains of all the elements which are anticipated in theory of smart grids. In the model there we can find a distributed generation, a local micro grid which is formed from a residential area, a settlement representing the medium-volume consumer and a factory representing high-volume consumption. Furthermore, on the model we can find the central battery serving for power balance management and the connection to the superior power electricity grid. The visualization of the model is performed so that the model clearly provides the understanding of the smart grid model. It is possible to use the model as a learning material for initial familiarization with the operation and the topology of the smart grid. The model is equipped with various visual elements: there are LEDs and small DC motors. Everything is controlled by the control board directly created for the managing this model. The microprocessor of the control board is programmed so that the model works in several modes with various value of electric power generated by the distributed generators. The text part of the bachelor thesis is divided into two parts. The first part contains theoretical analysis of the smart grids. The second part deals with the physical model: there is the model description, the description of its functional modes, schematics of circuit boards which were used in the model, details pictures of the model individual parts and drawings created during the design phase of the model creation process.410 - Katedra elektroenergetikyvýborn

System for optimizing the operation of the electrical distribution network

Evropská elektroenergetika dnes prochází velkými změnami a velká část těchto změn se nějak dotýká elektrických distribučních sítí. Ty procházejí proměnou v moderní „chytré“ distribuční sítě. Až bude tato proměna dokončena, elektrické distribuční sítě budou vybaveny velkým množstvím měřicích a řídicích zařízení a komunikačními sítěmi přenášejícími data mezi všemi těmi měřicími a řídicími zařízeními a řídicím počítačem, přičemž přenášená data budou popisovat stav různých entit souvisejících s danou distribuční sítí. Na řídicím počítači bude spuštěn software, který v čase blízkém reálnému bude na základě dat z těch měřicích zařízení určovat, jak mají být jednotlivá řízená zařízení instalovaná v distribuční síti nastavena, aby daná distribuční síť pracovala co nejlépe – tedy co nejstabilněji, nejkvalitněji a nejbezpečněji. Tato disertační práce prezentuje software, který má ambice i schopnosti být tím, který bude řídit různé prvky ovlivňující výkonové toky v moderních distribučních sítích. Tento software je vybaven tak, aby za normálního provozního stavu řízené distribuční sítě dokázal tuto síť řídit optimálně. Optimálně zde znamená řídit tak, aby kolísání velikosti napětí napříč sítí bylo minimální, místní výrobní a akumulační kapacity byly využity optimálně, velikost ztrát elektrické energie v jednotlivých prvcích sítě byla minimální anebo volné přenosové kapacity byly co nejvyšší. Upřednostňovaný cíl řízení dané distribuční sítě si její provozovatel může ve zdejším softwaru sám určit pomocí nastavení vah jednotlivých sledovaných veličin. Při výskytu poruchy na jednom či více z prvků řízené distribuční sítě pak tento software poskytne jejímu provozovateli návod, jak při odstraňování zdejších poruch postupovat, tak aby celkové množství elektrické energie, která nebude v průběhu procesu odstraňování poruchy dodána místním odběratelům, bylo co nejnižší.Today, the European electrical-power industry is undergoing big changes, and a large part of them relates to electrical distribution networks. The electrical distribution networks are undergoing a transformation into modern "smart" distribution networks. Modern smart distribution networks will be equipped with many measuring and control devices, and communication networks transferring data between all those measuring and control devices and the control computer. On the control computer, there will be software running in a close-to-real-time regime. Using data from those measuring devices, this software will determine how the individual control devices installed in the distribution network should be set up so that the distribution network works as best as possible – i.e., as stable, quality, and operationally robust as possible. This dissertation presents software that has the ambition and ability to be the controller of a modern distribution network. This software is equipped so that under normal operating conditions of the distribution network it can control this network optimally, i.e., with minimal voltage fluctuations across the network, optimal use of local production and storage capacity, minimal active-power losses in individual network elements or with the highest possible available transmission capacities. The control process’ preferred goals for a given network can be determined by the network operator by setting the weights of individual observed variables. If one or more faults occur on elements of the controlled distribution network, this software will provide the network operator with instructions on how to proceed in eliminating the faults so that the total amount of electrical energy not supplied to local customers is as low as possible.410 - Katedra elektroenergetikyvyhově

Application for electrical grid modelling

Náplní této diplomové práce je vytvoření programu pro simulaci chodu elektrické sítě. Simulace jsou prováděny na modelu distribuční sítě pracující na napěťové hladině 110 kV. Uživatel vytvořeného programu může v rámci jediné simulace chodu této sítě vyvolat různé události a sledovat jejich dopad na jednotlivé veličiny popisující různé částí sítě. Těmito událostmi můžou být změny konfigurace sítě (pomocí zapínaní a vypínání jednotlivých vedení) nebo změny velikosti odebíraného nebo dodávaného výkonu v jednotlivých uzlech sítě. Tento program představuje pracovní pomůcku, která uživateli názorně a přehledně zobrazí výsledky simulace, jejíž podobu může uživatel ovlivnit velkou škálou nastavitelných parametrů. Jednotlivé simulace programu se skládají ze sekvence stavů. Program vytváří popis těchto stavů pomocí výpočtu matematického modelu zachycujícího svým nastavením daný časový okamžik simulace. Program nabízí dva módy simulace. V prvním módu pracuje zkoumaná distribuční síť ve spojení s nadřazenou přenosovou sítí, která zajišťuje vyrovnanou výkonovou bilanci v distribuční síti. V druhém módu pracuje distribuční síť izolovaně od přenosové sítě a vyrovnané výkonové bilance je dosahováno pomocí regulace výkonů místních zdrojů a odběratelů. Diplomová práce má část teoretickou a praktickou. V teoretické části jsou obecně popsány metody a principy použité při tvorbě programu. Tato část práce se tak věnuje obecnému fyzikálnímu a matematickému popisu elektrických sítí, popisu rozdílu mezi úlohami lineárními a nelineárními, obecnému popisu numerických metod využívaných při řešení nelineárních úloh a také aplikaci těchto numerických metod na úlohy analyzující ustálený chod elektrické sítě. Druhá, praktická část práce se věnuje popisu samotného programu pro simulaci chodu elektrických sítí. V této části je tak popsáno funkční jádro programu, které počítá jednotlivé stavy sekvence simulace, a grafické prostředí, skrze které uživatel program ovládá.The aim of this diploma thesis is to create a program for the simulation of the electric power system operation. The simulations are performed on the model of distribution network which operates at the 110 kV voltage level. The user of the program can make various events in a single simulation of the power system operation and watch their impact on the values of the system variables. These events include changes of the network configuration (by switching on or off the individual lines) or changes of the amount of power which is taken or delivered at the nodes of the network. The created program is a tool that clearly displays the results of the simulation, the form of which can be influenced by a wide range of adjustable parameters. The program simulations consist of a sequence of states. The program creates descriptions of individual states by calculating a mathematical model set according to the setting for the appropriate time step of simulation. The program works in two simulation modes. In the first mode, the distribution network operates in connection with the superior transmission system which provides a balanced power balance in the distribution system. In the second mode, the distribution network is not connected to the transmission system by any line and the balanced power balance is achieved by regulation of the local power sources and the local power customers. The diploma thesis has a theoretical and practical part. The theoretical part describes in general the methods and principles used during the creation of the program. This part of the text deals with the general physical and mathematical description of the electric power systems, the general description of the difference between linear and nonlinear tasks, the general description of numerical methods used for solving nonlinear systems and the application of these numerical methods in solving the tasks analyzing steady operation of the electric power system. The second, practical part of the thesis describes the program for the simulation of electric power system. This section describes the functional kernel of the program that calculates the individual states of the simulation sequence and the graphical environment through which the user controls the program.410 - Katedra elektroenergetikyvýborn

Domain knowledge specification for energy tuning

To overcome the challenges of energy consumption of HPC systems, the European Union Horizon 2020 READEX (Runtime Exploitation of Application Dynamism for Energy-efficient Exascale computing) project uses an online auto-tuning approach to improve energy efficiency of HPC applications. The READEX methodology pre-computes optimal system configurations at design-time, such as the CPU frequency, for instances of program regions and switches at runtime to the configuration given in the tuning model when the region is executed. READEX goes beyond previous approaches by exploiting dynamic changes of a region's characteristics by leveraging region and characteristic specific system configurations. While the tool suite supports an automatic approach, specifying domain knowledge such as the structure and characteristics of the application and application tuning parameters can significantly help to create a more refined tuning model. This paper presents the means available for an application expert to provide domain knowledge and presents tuning results for some benchmarks.Web of Science316art. no. E465

Steady-State Analysis of Electrical Networks in Pandapower Software: Computational Performances of Newton–Raphson, Newton–Raphson with Iwamoto Multiplier, and Gauss– Seidel Methods

At the core of every system for the efficient control of the network steady-state operation is the AC-power-flow problem solver. For local distribution networks to continue to operate effectively, it is necessary to use the most powerful and numerically stable AC-power-flow problem solvers within the software that controls the power flows in these networks. This communication presents the results of analyses of the computational performance and stability of three methods for solving the AC-power-flow problem. Specifically, this communication compares the robustness and speed of execution of the Gauss–Seidel (G–S), Newton–Raphson (N–R), and Newton–Raphson method with Iwamoto multipliers (N–R–I), which were tested in open-source pandapower software using a meshed electrical network model of various topologies. The test results show that the pandapower implementations of the N–R method and the N–R–I method are significantly more robust and faster than the G–S method, regardless of the network topology. In addition, a generalized Python interface between the pandapower and the SciPy package was implemented and tested, and results show that the hybrid Powell, Levenberg–Marquardt, and Krylov methods, a quasilinearization algorithm, and the continuous Newton method can sometimes achieve better results than the classical N–R method

Domain Knowledge Specification for Energy Tuning

The European Horizon 2020 project READEX is developing a tool suite for dynamic energy tuning of HPC applications. While the tool suite supports an automatic approach, domain knowledge can significantly help in the analysis and the runtime tuning phase. This paper presents the means available in READEX for the application expert to provide his expert knowledge to the tool suite

OPF solution for a real Czech urban meshed distribution network using a genetic algorithm

Electrical distribution networks are facing an energy transition which entails an increase of decentralised renewable energy sources and electric vehicles. The resulting temporal and spatial uncertainty in the generation/load patterns challenges the operations of an infrastructure not designed for such a transition. In this situation, Optimal Power Flow methods can play a key role in identifying system weak points and supporting efficient management of the electrical networks, including the distribution level. In this work, to support distribution system operators' decision-making process, we aim at attaining a quasi-optimal solution in the shortest time possible in an electrical network experiencing a large growth of distributed energy sources. We propose an optimisation method based on a modified version of a genetic algorithm and the Python pandapower package. The method is tested on a model of a real urban meshed network of a large Czech city. The optimisation method minimises the total operating costs of the distribution network by controlling selected network components and parameters, namely the transformer tap changers and the active power demand at consumption nodes. The results of our method are compared with the exact solution showing that a close-to-optimal solution of the observed problem can be reached in a relatively short time.Web of Science26art. no. 10043

Steady-State Analysis of Electrical Networks in Pandapower Software: Computational Performances of Newton–Raphson, Newton–Raphson with Iwamoto Multiplier, and Gauss–Seidel Methods

At the core of every system for the efficient control of the network steady-state operation is the AC-power-flow problem solver. For local distribution networks to continue to operate effectively, it is necessary to use the most powerful and numerically stable AC-power-flow problem solvers within the software that controls the power flows in these networks. This communication presents the results of analyses of the computational performance and stability of three methods for solving the AC-power-flow problem. Specifically, this communication compares the robustness and speed of execution of the Gauss–Seidel (G–S), Newton–Raphson (N–R), and Newton–Raphson method with Iwamoto multipliers (N–R–I), which were tested in open-source pandapower software using a meshed electrical network model of various topologies. The test results show that the pandapower implementations of the N–R method and the N–R–I method are significantly more robust and faster than the G–S method, regardless of the network topology. In addition, a generalized Python interface between the pandapower and the SciPy package was implemented and tested, and results show that the hybrid Powell, Levenberg–Marquardt, and Krylov methods, a quasilinearization algorithm, and the continuous Newton method can sometimes achieve better results than the classical N–R method

Steady-state analysis of electrical networks in pandapower software: Computational performances of Newton-Raphson, Newton-Raphson with Iwamoto multiplier, and Gauss-Seidel methods

At the core of every system for the efficient control of the network steady-state operation is the AC-power-flow problem solver. For local distribution networks to continue to operate effectively, it is necessary to use the most powerful and numerically stable AC-power-flow problem solvers within the software that controls the power flows in these networks. This communication presents the results of analyses of the computational performance and stability of three methods for solving the AC-power-flow problem. Specifically, this communication compares the robustness and speed of execution of the Gauss–Seidel (G–S), Newton–Raphson (N–R), and Newton–Raphson method with Iwamoto multipliers (N–R–I), which were tested in open-source pandapower software using a meshed electrical network model of various topologies. The test results show that the pandapower implementations of the N–R method and the N–R–I method are significantly more robust and faster than the G–S method, regardless of the network topology. In addition, a generalized Python interface between the pandapower and the SciPy package was implemented and tested, and results show that the hybrid Powell, Levenberg–Marquardt, and Krylov methods, a quasilinearization algorithm, and the continuous Newton method can sometimes achieve better results than the classical N–R method.Web of Science144art. no. 200