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Requirements for control strategies of grid-connected converters in the future power system

IET RENEWABLE POWER GENERATION 2020年第8期14卷 1288-1295页

作者： Emanuel, Hanna Brombach, Johannes Rosso, Roberto Pierros, Konstantinos ENERCON GmbH Sales Grid Integrat Bremen Germany WRD GmbH Control Syst Aurich Germany

the increasing penetration of converter-based generation in many power systems around the world has sparked a discussion about how to operate these power systems with the usual levels of efficiency, reliability and cost-effectiveness. Current grid-following converter-based generators have proven to run stably in parallel to one another, even if there are thousands of them connected in a power system, and even in very small isolated power systems with extremely low system inertia. Discussions around the necessity of additional converter performance, usually under the 'grid-forming' and 'Virtual Synchronous Machines' concepts, have recently been transferred from the academic sphere to national and international industry fora. Formal discussions have started in Great Britain, in Germany and at ENTSO-E level. However, there is still a lot of uncertainty about the real and not simulated performance of grid-forming converters, whilst the needs case for requiring this radically different control method has not been adequately justified. With the present paper we raise key questions that will serve towards an objective discussion about power system needs, grid infeed technologies and their interaction.

关键词： distributed power generation power grids power convertors synchronous machines converter-based generation isolated power systems low system inertia grid-forming converters grid-connected converters virtual synchronous machines grid-forming concepts Great Britain Germany ENTSO-E level grid infeed technology grid-forming concept

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Modelling of nanometer scale dust grains in tokamak

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CONTRIBUTIONS TO PLASMA PHYSICS 2020年第5-6期60卷 e201900136-e201900136页

作者： Liu, Zhuang Xiao, Xiaotao Xu, Xueqiao Li, Nami Tang, Tengfei Wang, Dezhen Dalian Univ Technol Phys Dept Dalian 116024 Peoples R China Lawrence Livermore Natl Lab Livermore CA 94550 USA Chinese Acad Sci Inst Plasma Phys Hefei Peoples R China

Dust poses a serious threat to tokamak operation and safety. It is important to study the behaviour of dust grains under tokamak's discharge conditions, which depends heavily on their size and charge. Existing simulations mainly address issues on dust grains with radii larger than 1 mu m, in which case, the drift effect due to electromagnetic fields can be safely ignored. For nanometer scale dust grains, however, the drift effect becomes significant and a new model based on guiding-centre system needs to be established. In this work, the NDS has been done under BOUT++ framework. the simulation contains two parts. Part one, NDS evaluates the charging and ablation processes of the dust grains. In the second part, the guiding-centre orbits of dust particles are tracked in tokamak plasmas, whose parameters are obtained from BOUT++, a highly desirable C++ code package for performing parallel plasma fluid simulations with an arbitrary number of equations in 3D curvilinear coordinates. the orbit of nanodust dynamics is described by guiding centre equations for simplicity, and these equations are numerically solved by conventional fourth-order Runge Kutta method. simulations provide results such as trajectories and evolutions of dust particles with different sizes and velocities for different tokamak geometries. Results show tungsten dust grains with a radius of a few nanometers launched from outer midplane will oscillate before totally ablated in C-Mod. the oscillation in this case is driven by the ion drag force. Larger Nanodust with a radius of 100 nm, on the contrary, cannot be completely constrained by the electromagnetic field. the high plasma temperature and density in the seperatrix region causes severe dust ablation, resulting in total ablation within several ms.

关键词： BOUT plus plus Nanodust plasma simulation tokamak

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IOT and cloud computing based parallel implementation of optimized RBF neural network for loader automatic shift control

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COMPUTER COMMUNICATIONS 2020年 158卷 95-103页

作者： Wu, Guanghua Ma, Wenxing Liu, Chunbao Wang, Songlin Jilin Univ Sch Mech Sci & Aerosp Engn Changchun 130012 Peoples R China Jilin Engn Normal Univ Automot & Engn Changchun 130052 Peoples R China Guangxi Liugong Machinery Co Ltd Guangxi 545007 Peoples R China

One of the key issues in automatic shift control of V-type cyclical loaders is determining how to find the best gear for the current conditions according to a certain mapping relation, but this complex and nonlinear mapping is difficult to express by a mathematical relation. However, to solve such nonlinear problems, a radial basis function (RBF) neural network is the best choice. In this paper, a certain type of wheel loader is taken as the research object, and an RBF neural network algorithm based on an improved genetic algorithm (GA) optimization is proposed. the global search ability of the GA is improved by adaptively adjusting the crossover probability and mutation probability. the RBF neural network expansion coefficient is optimized by an improved GA. Using industrial IOT technology, an optimized RBF neural network based on Map-Reduce on a cloud computing cluster is designed. the diesel engine computer and transmission computer on the loader are integrated to achieve dual-processor distributed parallel data processing and calculation. then the loader automatic variable speed control algorithm model of improved GA optimized RBF neural network based on IOT cloud computing is established. the network model is trained and simulated using real vehicle automatic shift test data. the simulation results show that the improved GA-RBF neural network algorithm can achieve a correct recognition rate of 97.92%. the error matrix norm reaches the minimum value when the algorithm is iterated to the 17th generation. the improved algorithm has the advantages of a high gear recognition rate, fast convergence speed and strong real-time shift performance and is an effective new shift control method. the test results show that the shift boost time is less than 0.15 s and has a certain gradient. Compared with the manual shift process performed in the past, some improvements are achieved in the optimal shift time, shift response speed and shift quality. Compared with the traditiona

关键词： IOT Cloud computing RBF neural network Automatic shift control

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Requirements for control strategies of grid-connected converters in the future power system

Requirements for control strategies of grid-connected conver...

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17th Wind and the 8th Solar Integration workshop

作者： Emanuel, Hanna Brombach, Johannes Rosso, Roberto Pierros, Konstantinos ENERCON GmbH Sales Grid Integrat Bremen Germany WRD GmbH Control Syst Aurich Germany

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14th International workshop on Artificial Life and Evolutionary Computation, WIVACE 2019

14th International Workshop on Artificial Life and Evolution...

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14th International workshop on Artificial Life and Evolutionary Computation, WIVACE 2019

ISBN: (纸本)9783030450151

the proceedings contain 17 papers. the special focus in this conference is on Artificial Life and Evolutionary Computation. the topics include: An analysis of cooperative coevolutionary differential evolution as neural networks optimizer;Design and evaluation of a heuristic optimization tool based on evolutionary grammars using PSoCs;how word choice affects cognitive impairment detection by handwriting analysis: A preliminary study;modeling the coordination of a multiple robots using nature inspired approaches;nestedness temperature in the agent-artifact space: Emergence of hierarchical order in the 2000–2014 photonics techno-economic complex system;towards programmable chemistries;studying and simulating the three-dimensional arrangement of droplets;investigating three-dimensional arrangements of droplets;selecting for positive responses to knock outs in boolean networks;avalanches of perturbations in modular gene regulatory networks;the effects of a simplified model of chromatin dynamics on attractors robustness in random boolean networks with self-loops: An experimental study;a memetic approach for the orienteering problem;the detection of dynamical organization in cancer evolution models;the simulation of noise impact on the dynamics of a discrete chaotic map;exploiting distributed discrete-event simulation techniques for parallel execution of cellular automata.

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Grid forming control scheme for power systems with up to 100% power electronic interfaced generation: a case study on Great Britain test system

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IET RENEWABLE POWER GENERATION 2020年第8期14卷 1268-1281页

作者： Ndreko, Mario Rueberg, Sven Winter, Wilhelm TenneT TSO GmbH Asset Management Grid Planning Bayreuth Germany

the penetration of power electronic interfaced generation (PEIG) is expected to reach up to 65% in some parts of the European power system by 2030 (at least during some hours of the year). Under such grid conditions, system security challenges are observed with frequency stability, voltage stability and undamped converter control interactions being among the most important issues. this study presents a short-term voltage stability assessment of the Great Britain synchronous area under EMT modelling assumptions. the study provides a mapping of system stability and identifies the critical penetration level of PEIG that instabilities are observed. In addition, an application of a grid forming control scheme (namely the enhanced direct power control) is proposed as a mitigation option which is applied here on full-converter interfaced wind power plants (type-4). the simulation results reveal that the application of the grid forming control to a part of the total wind power generation fleet can mitigate the instabilities observed, while enabling the system operation with 100% PEIG.

关键词： power electronics power control power generation control power grids wind power plants wind power power system stability distributed power generation power convertors 100% PEIG grid forming control scheme power systems 100% power electronic interfaced generation Great Britain test system European power system grid conditions system security challenges frequency stability converter control interactions short-term voltage stability assessment Great Britain synchronous area system stability critical penetration level enhanced direct power control full-converter interfaced wind power plants total wind power generation fleet system operation

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(Poster) parallel and distributed Operation of Smart Grid with Pulsed Power Transmission 22

(Poster) Parallel and Distributed Operation of Smart Grid wi...

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22nd IEEE International Conference on Computational Science and Engineering (IEEE CSE) / 17th IEEE International Conference on Embedded and Ubiquitous Computing (IEEE EUC)

作者： Sugiyama, Hisayoshi Osaka City Univ Dept Phys Elect & Informat Osaka Japan

ISBN: (纸本)9781728116648

parallel and distributed operation of pulsed power network with potential gradient method is confirmed with moderately large scale simulation model. the pulsed power network is already proposed for seamless integration of distributed generations. PG method brings the scalability on the network. To confirm the scalability of this power grid and autonomous clustering around the generations, computer simulations are executed.

关键词： Internet of energy Smart grid distributed operation Pulsed power network

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Approaches for in situ computation of moments in a data-parallel environment

Approaches for in situ computation of moments in a data-para...

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20th Eurographics Symposium on parallel Graphics and Visualization, EGPGV 2020

作者： Tsai, Karen C. Bujack, Roxana Geveci, Berk Ayachit, Utkarsh Ahrens, James Los Alamos National Laboratory Kitware Inc.

ISBN: (纸本)9783038681076

Feature-driven in situ data reduction can overcome the I/O bottleneck that large simulations face in modern supercomputer architectures in a semantically meaningful way. In this work, we make use of pattern detection as a black box detector of arbitrary feature templates of interest. In particular, we use moment invariants because they allow pattern detection independent of the specific orientation of a feature. We provide two open source implementations of a rotation invariant pattern detection algorithm for high performance computing (HPC) clusters with a distributed memory environment. the first one is a straightforward integration approach. the second one makes use of the Fourier transform and the Cross-Correlation theorem. In this paper, we will compare the two approaches with respect to performance and flexibility and showcase results of the in situ integration with real world simulation code. © 2020 the Author(s) Eurographics Proceedings © 2020 the Eurographics Association.

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Automated integration of continental-scale observations in near-real time for simulation and analysis of biosphere-atmosphere interactions 17th

Automated integration of continental-scale observations in n...

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17th Smoky Mountains Computational Sciences and Engineering Conference, SMC 2020

作者： Durden, David J. Metzger, Stefan Chu, Housen Collier, Nathan Davis, Kenneth J. Desai, Ankur R. Kumar, Jitendra Wieder, William R. Xu, Min Hoffman, Forrest M. National Ecological Observatory Network Program Battelle BoulderCO80301 United States Department of Atmospheric and Oceanic Sciences University of Wisconsin MadisonWI53706 United States Lawrence Berkeley National Laboratory BerkeleyCA94702 United States Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Meteorology and Atmospheric Science and Earth and Environmental Systems Institute The Pennsylvania State University University ParkPA16802 United States Bredesen Center University of Tennessee KnoxvilleTN37996 United States Climate and Global Dynamics Laboratory National Center for Atmospheric Research BoulderCO80307 United States Institute of Arctic and Alpine Research University of Colorado BoulderCO80309 United States Department of Civil and Environmental Engineering University of Tennessee KnoxvilleTN37996 United States

ISBN: (纸本)9783030633929

the National Ecological Observatory Network (NEON) is a continental-scale observatory with sites across the US collecting standardized ecological observations that will operate for multiple decades. To maximize the utility of NEON data, we envision edge computing systems that gather, calibrate, aggregate, and ingest measurements in an integrated fashion. Edge systems will employ machine learning methods to cross-calibrate, gap-fill and provision data in near-real time to the NEON Data Portal and to High Performance Computing (HPC) systems, running ensembles of Earth system models (ESMs) that assimilate the data. For the first time gridded EC data products and response functions promise to offset pervasive observational biases through evaluating, benchmarking, optimizing parameters, and training new machine learning parameterizations within ESMs all at the same model-grid scale. Leveraging open-source software for EC data analysis, we are already building software infrastructure for integration of near-real time data streams into the International Land Model Benchmarking (ILAMB) package for use by the wider research community. We will present a perspective on the design and integration of end-to-end infrastructure for data acquisition, edge computing, HPC simulation, analysis, and validation, where Artificial Intelligence (AI) approaches are used throughout the distributed workflow to improve accuracy and computational performance. © Springer Nature Switzerland AG 2020.

关键词： Data acquisition

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Grid forming control scheme for power systems with up to 100% power electronic interfaced generation: a case study on Great Britain test system

Grid forming control scheme for power systems with up to 100...

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17th Wind and the 8th Solar Integration workshop

作者： Ndreko, Mario Rueberg, Sven Winter, Wilhelm TenneT TSO GmbH Asset Management Grid Planning Bayreuth Germany

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