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arXiv 2022年

作者： Schäfer, Benjamin Gorjão, Leonardo Rydin Cigdem, G. Yalcin Förstner, Ellen Jumar, Richard Maass, Heiko Kühnapfel, Uwe Hagenmeyer, Veit Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Eggenstein-Leopoldshafen76344 Germany Department of Computer Science OsloMet - Oslo Metropolitan University OsloN-0130 Norway Jülich52428 Germany Department of Physics Istanbul University Vezneciler 34134 Turkey

Complex systems, such as the power grid, are essential for our daily lives. Many complex systems display (multi-)fractal behavior, correlated fluctuations and power laws. Whether the power-grid frequency, an indicator about the balance on supply and demand in the electricity grid, also displays such complexity remains a mostly open question. Within the present article, we utilize highly resolved measurements to quantify the properties of the power-grid frequency. We show that below 1 second, the dynamics may fundamentally change, including a suddenly increasing power spectral density, emergence of multifractality and a change of correlation behavior. We provide a simplified stochastic model involving positively correlated noise to reproduce the observed dynamics, possibly linked to frequency dependent loads. Finally, we stress the need for high-quality measurements and discuss how we obtained the data analyzed here. © 2022, CC BY.

关键词： Stochastic models

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A New Julia-Based Parallel Time-Domain Simulation Algorithm for Analysis of Power System Dynamics

A New Julia-Based Parallel Time-Domain Simulation Algorithm ...

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International Workshop/Symposium on Distributed Simulation and Real-Time Applications (DS-RT)

作者： Michael Kyesswa Philipp Schmurr Hüseyin K. Çakmak Uwe Kühnapfel Veit Hagenmeyer Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany

ISBN: (数字)9781728173436

ISBN: (纸本)9781728173443

The present paper describes a new parallel time-domain simulation algorithm using a high performance computing environment - Julia - for the analysis of power system dynamics in large networks. The parallel algorithm adapts a parallel-in-space decomposition scheme to a previously sequential algorithm in order to develop a new parallelizable numerical solution of the power system equations. The parallel-in-space decomposition is based on the block bordered diagonal form, which reformulates the network admittance matrix into sub-blocks that can be solved in parallel. For the optimal spatial decomposition of the network, a new extended graph partitioning strategy is developed for load balancing and minimizing the communication between subnetworks. The new parallel simulation algorithm is tested using standard test networks of varying complexity. The simulation results are compared to those obtained from a sequential implementation in order to validate the solution accuracy and to determine the performance improvement in terms of computational speedup. Test simulations are conducted using the ForHLR II supercomputing cluster and show a huge potential in computational speedup with increasing network complexity.

关键词： Mathematical model Computational modeling Power system stability Power system dynamics Heuristic algorithms Partitioning algorithms Analytical models

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Dynamic Modeling of Wind and Solar Power Generation with Grid Support for Large-Scale Integration in Power Systems

Dynamic Modeling of Wind and Solar Power Generation with Gri...

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IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT Europe)

作者： Michael Kyesswa Hüseyin Çakmak Uwe Kühnapfel Veit Hagenmeyer Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany

ISBN: (数字)9781728171005

ISBN: (纸本)9781728171012

The large-scale integration of variable and unpredictable renewable energy sources into the current networks necessitates considerable adjustments in operation and analysis strategies in order to ensure stability of power systems. The present paper describes the dynamic modeling and integration of solar PV and wind power generation systems into an open source toolbox for power system transient stability analysis. The main contribution is the development of high-level functions to model converter interfaces to the electrical network in reference to standard grid operation codes. The models and control functions are tested using a real network representing the transmission grid of the Baden-Württemberg state in Germany in order to analyze the inverter functions necessary for grid stability support. From the simulation results, it is observed that the developed control functions of the interfacing converters can equip renewable energy generators with equivalent features to synchronous machines from a functional point of view.

关键词： Analytical models Power system dynamics Stability criteria Power system stability Wind power generation Standards Load modeling

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Diagnostics of the machines and devices based on the simatic prodiag 9th

Diagnostics of the machines and devices based on the simatic...

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9th Computer Science On-line Conference, CSOC 2020

作者： Kopcek, Michal Fackova, Miroslava Faculty of Materials Science and Technology in Trnava Institute of Applied Informatics Automation and Mechatronics in Bratislava Slovak University of Technology J. Bottu 52 Trnava91724 Slovakia

ISBN: (纸本)9783030519735

The paper is focused on the diagnostics of machines and devices based on the SIMATIC ProDiag library for the machines produced by company Skartek, s. r. o. The first part is dedicated to theoretical problem description and analysis. The next part of the work describes a sample example with configuration of supervisions, which serves as a demonstration for the implementation of the ProDiag library. Testing of the example and the implemented ProDiag library functions are followed by an evaluation of the ProDiag library’s utility within production of the Skartek company. The next part is comparison of alarm handling by conventional ways and by using the ProDiag library. At the end we will show the advantages and disadvantages of the shown methods of alarm handling. © Springer Nature Switzerland AG 2020.

关键词： Alarm systems

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Adaptive test case selection for DNN-based perception functions

Adaptive test case selection for DNN-based perception functi...

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IEEE International Symposium on Systems Engineering (ISSE)

作者： Johannes Bernhard Thomas Schulik Mark Schutera Eric Sax Institute for Information Processing Technologies Karlsruhe Institue of Technology Germany Research and Development ZF Friedrichshafen AG Institute for Automation and Applied Informatics Karlsruhe Institue of Technology Germany

The progress in deep learning methods has bolstered the development of automated vehicles during the last decade. However, the deployment of deep learning methods in safety-critical applications raised questions on their safety. Like other vehicle components, a testing process has to prove the reliability of perception systems. Scalability issues arise when using real-world data to validate perception algorithms due to the immense amount of sensor data that needs to be tested. Simulation tools can complement this testing process, as they can fabricate synthetic data based on variable specifications of test cases. While simulative tools can produce a vast amount of test data, at some point, the testing process is limited by the available computing resources. Identifying test specifications that pose risks to the perception algorithms is crucial for efficiently utilizing these computing resources and estimating functional reliability. We present a pipeline for adaptive test case selection to expose the faults of a deep learning system using synthetic image data generated by a simulation framework. We apply our concept to a state-of-the-art object detector and implement multiple adaptive sampling strategies to demonstrate their ability of early fault detection. Our experiments show that our pipeline can achieve a 95% coverage of system faults while reducing the number of test executions by 90%.

关键词： Deep learning Adaptive systems Computational modeling Scalability Pipelines Tools Data models

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Evaluating contextualized language models for Hungarian

arXiv

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arXiv 2021年

作者： Ács, Judit Lévai, Dániel Nemeskey, Dávid Márk Kornai, András Department of Automation and Applied Informatics Budapest University of Technology and Economics Hungary Institute for Computer Science and Control Hungary Alfréd Rényi Institute of Mathematics Hungary

We present an extended comparison of contextualized language models for Hungarian. We compare huBERT, a Hungarian model against 4 multilingual models including the multilingual BERT model. We evaluate these models through three tasks, morphological probing, POS tagging and NER. We find that huBERT works better than the other models, often by a large margin, particularly near the global optimum (typically at the middle layers). We also find that huBERT tends to generate fewer subwords for one word and that using the last subword for token-level tasks is generally a better choice than using the first one. Copyright © 2021, The Authors. All rights reserved.

关键词： Computational linguistics

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On the isolated calmness property of implicitly defined multifunctions

arXiv

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arXiv 2022年

作者： Gfrerer, Helmut Outrata, Jiří V. Institute of Computational Mathematics Johannes Kepler University Linz LinzA-4040 Austria Institute of Information Theory and Automation Czech Academy of Sciences Prague18208 Czech Republic Centre for Informatics and Applied Optimization Federation University of Australia POB 663 BallaratVIC3350 Australia

The paper deals with an extension of the available theory of SCD (subspace containing derivatives) mappings to mappings between spaces of different dimensions. This extension enables us to derive workable sufficient conditions for the isolated calmness of implicitly defined multifunctions around given reference points. This stability property differs substantially from isolated calmness at a point and, possibly in conjunction with the Aubin property, offers a new useful stability concept. The application area includes a broad class of parameterized generalized equations, where the respective conditions ensure a rather strong type of Lipschitztan behavior of their solution *** Codes 65K10, 65K15, 90C33 © 2022, CC BY.

关键词： Mapping

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Integrating battery aging in the optimization for bidirectional charging of electric vehicles

arXiv

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arXiv 2020年

作者： Schwenk, Karl Meisenbacher, Stefan Briegel, Benjamin Harr, Tim Hagenmeyer, Veit Mikut, Ralf Mercedes-Benz AG Sindelfingen Germany Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany

Smart charging of Electric Vehicles (EVs) reduces operating costs, allows more sustainable battery usage, and promotes the rise of electric mobility. In addition, bidirectional charging and improved connectivity enables efficient power grid support. Today, however, uncoordinated charging, e.g. governed by users' habits, is still the norm. Thus, the impact of upcoming smart charging applications is mostly unexplored. We aim to estimate the expenses inherent with smart charging, e.g. battery aging costs, and give suggestions for further research. Using typical on-board sensor data we concisely model and validate an EV battery. We then integrate the battery model into a realistic smart charging use case and compare it with measurements of real EV charging. The results show that i) the temperature dependence of battery aging requires precise thermal models for charging power greater than 7 kW, ii) disregarding battery aging underestimates EVs' operating costs by approx. 30%, and iii) the profitability of Vehicle-to-Grid (V2G) services based on bidirectional power flow, e.g. energy arbitrage, depends on battery aging costs and the electricity price spread. © 2020, CC BY.

关键词： Neural networks

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Field Experiments with an Automated Utility Platform for Transportation and Work Processes

Field Experiments with an Automated Utility Platform for Tra...

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IEEE International Conference on Autonomous Robot Systems and Competitions (ICARSC)

作者： Raimund Edlinger Stefan Dumberger Roman Froschauer Wolfgang Pointner Marcel Zeilinger Andreas Nü chter Smart Automation and Robotics University of Applied Sciences Upper Austria Wels Austria Assistive &#x0026 Autonomous Systems AIT &#x2013 Austrian Institute of Technology Vienna Austria Informatics VII - Robotics and Telematics Julius-Maximilians-University W&#x00FC rzburg W&#x00FC rzburg Germany

The automation of transport and work tasks in various application domains continues to be a major challenge. The proposed paper presents key technologies within a process from sensing to reasoning and includes: (i) understanding the scene and its relations through new approaches in object classification and pose estimation based on machine learning, as well as methods for reliable detection of objects and object features; (ii) reliable and safe outdoor localization and mapping based on multi-modal approaches and innovative camera-based methods. The fusion of different sensor data is used for reliable obstacle detection and collision avoidance. The investigation of suitable system architectures, data processing platforms and communication mechanisms taking into account safety requirements is a prerequisite for the operation in a safety-critical environment. The paper provides a proof of concept for an automated platform to demonstrate and evaluate application scenario provided by the Linz Airport in the form of an automated transport process for air freight between a terminal and the aircraft.

关键词： Navigation Transportation Systems architecture Switches Robot sensing systems Software Software reliability

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Computer modeling application of fluid outflow from vessels

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Materials Science Forum 2019年 952卷 250-257页

作者： Kraváriková, Helena Faculty of Materials Science and Technology in Trnava Institute of Applied Informatics Automation and Mechatronics Bottova 26 Trnava917 24 Slovakia

The aim of the paper is to evaluate numerical analysis of the fluid flow during the outflow from vessel orifices at various locations. The problems of the outflow velocities and pressure fields were well-chosen for the given purposes. The selected fluid flow problems were solved by numerical simulation using FEM in ANSYS. For numerical simulation, we used the basic steps to design an abstract model in the ANSYS virtual environment. Numerical simulation requires a geometric model complemented by physical properties of flowing fluids as well as both the initial and boundary conditions. It is then possible to calculate the velocity and pressure fields by numerical simulation for a particular fluid type. The results obtained from the numerical simulation were compared with those of the analytical solution. The results obtained from modeling and numerical simulation correspond to the actual values with minimum deviations. The demonstrated type of the problem solved by numerical simulation and modeling confirmed the advantages and possibilities of flexible solutions for any combination of problems in the field of fluid dynamics. Modeling and numerical simulation of fluid flow can provide results regarding the speed and the pressure fields in vessels and pipelines. © 2019 Trans Tech Publications Ltd, Switzerland.

关键词： Orifices

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