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synchronization algorithms for grid-connected renewable systems: Overview, tests and comparative analysis

RENEWABLE & SUSTAINABLE ENERGY REVIEWS 2017年 75卷 629-643页

作者： Guerrero-Rodriguez, N. F. Rey-Boue, Alexis B. Bueno, E. J. Ortiz, Octavio Reyes-Archundia, Enrique PUCMM Engn Sci Av Abraham Lincoln Esq Romulo Betancourt Santo Domingo 2748 Dominican Rep Univ Politecn Cartagena Dept Elect Comp Technol & Projects C Dr Fleming S-N Murcia 30202 Spain Univ Alcala Elect Dept Ctra Madrid BarcelonaKm 33600 Madrid 28871 Spain Inst Tecnol Morelia Dept Syst & Comp Av Tecnol 1500 Morelia 58120 Michoacan Mexico Inst Tecnol Morelia Dept Elect Engn Av Tecnol 1500 Morelia 58120 Michoacan Mexico

This paper presents five synchronization algorithms that are commonly used in grid-connected renewable systems. The algorithm structures are studied and their corresponding block diagrams are shown and explained in detail. The behaviors of the algorithms are studied according of their response under voltage unbalances, frequency variations and low-order voltage harmonics. The advantages and disadvantages of the algorithms are discussed by analyzing some simulations done with MATLAB/SIMULINK tool from The MathWorks, Inc. Later on, the final validation is done by doing real-time digital tests of the synchronization algorithms with a Real Time Digital Simulator (RTDS) platform. A grid-connected photovoltaic system with a nominal power of 10 kW is used to evaluate the responses of the synchronization algorithms when the utility grid is affected by disturbances.

关键词： Grid-connected renewable systems synchronization algorithms 3-phase utility grid Voltage source inverter Real-Time Digital Simulation

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synchronization algorithms FOR PROGRAMMABLE LOGIC CONTROLLER EMULATION

SYNCHRONIZATION ALGORITHMS FOR PROGRAMMABLE LOGIC CONTROLLER...

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作者： Elwyn J. McCargar Air Force Institute of Technology

学位级别：硕士

Nations rely heavily on critical infrastructures to be the backbone of both the economy and the nation's general well-being. Many of these critical infrastructures depend on Industrial Control Systems (ICS). ICS is a general term used to describe an interaction where data is received from sensors and then actions are taken based off the data received. Most ICSs were designed and implemented before the Internet became widely used. When some systems were finally connected to the Internet, the emphasis was on the integrity of the data sent and the availability between devices, not the confidentiality. This lack of confidentiality is why ICS security is the focus of this research. The problem this research investigates is finding an optimal synchronization Al- gorithm used to synchronize a back-end Programmable Logic Controller (PLC) with a honeypot in the ScriptGenE Framework, which is a honeypot solution to ICS secu- rity. A honeypot is designed to emulate a desired device on the network and can be a superficial emulation or a complete replication of the desired device. This research uses the ScriptGenE Framework as a Hybrid Honeypot solution. ScriptGenE is a Hybrid Honeypot because each instance of the honeypot is only a superficial emulation with a finite amount of data about the device it is emulating. However, each honeypot is connected to a back-end PLC, identical to the device being emulated for the ability to provide more authentic responses than just a superficial emulation. synchronization between the back-end PLC and the honeypot is impor- tant for the emulation of a device's protocol because some protocols are stateful and provide responses to requests based on previous requests. The honeypot needs to ensure the back-end PLC is in the same state before sending a request to the PLC. This research hypothesizes: selecting a synchronization Algorithm for the Script- GenE Framework based on the shape and size of the protocol tree will yield faster latency respon

关键词： SCADA honeypot programmable logic controller industrial control systems automation emulator protocol reverse engineering synchronization algorithms

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GLOBAL AND LOCAL synchronization IN PARALLEL SPACE-AWARE APPLICATIONS 32

GLOBAL AND LOCAL SYNCHRONIZATION IN PARALLEL SPACE-AWARE APP...

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32nd European Conference on Modelling and Simulation (ECMS)

作者： Cicirelli, Franco Forestiero, Agostino Giordano, Andrea Mastroianni, Carlo Razumchik, Rostislav ICAR CNR Arcavacata Di Rende CS Italy FRC CSC RAS Inst Informat Problems Moscow Russia Peoples Friendship Univ Russia RUDN Univ Moscow Russia

ISBN: (纸本)9780993244070

Space-aware applications are characterized by an explicit representation of a spatial environment in which some entities live and operate by interacting with each other and with the hosting territory. A relevant space-aware application domain is the so-called urban computing, embracing issues like the simulation and implementation of public transportation systems, traffic management, urban monitoring and control. The execution of such applications is often distributed on parallel computing nodes, which need to cooperate and exchange data among each other, thus raising synchronization issues. In this paper we analyze time-related characteristics of the computational process in a space-aware application in the case when each node does not need global synchronization (i.e. synchronization with all other nodes) but requires only local synchronization (i.e. synchronization with a subset of neighbor nodes). Performance is evaluated both analytically and numerically. We provide the analytical support to an important conclusion: the mean computation time per step remains finite irrespective of the number of nodes under local synchronization, while under global synchronization it grows unboundedly as the number of nodes increases. In practical scenarios this corresponds to significantly better scalability properties of local synchronization.

关键词： synchronization algorithms parallel computing performance evaluation

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Preamble design and coarse synchronization using CAZAC sequence for uplink cable modem

Preamble design and coarse synchronization using CAZAC seque...

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International Multiconference of Engineers and Computer Scientists

作者： Kim, Youngje Lee, Junseo Ha, Hyunju Lee, Eungdon Song, Yun-Jeong Oh, Wangrok Kim, Whanwoo Chungnam Natl Univ Div Elect Engn Daejeon South Korea Elect & Telecommun Res Inst Radio & Broadcasting Div Daejeon South Korea

ISBN: (纸本)9789889867140

In this paper, we propose a preamble structure and appropriate acquisition algorithms for the uplink cable modem. The proposed preamble consists of a serial concatenation of identical constant amplitude zero autocorrelation (CAZAC) sequences. The proposed preamble is used for the frame detection, coarse symbol timing and carrier frequency recovery for the uplink cable modem compliant to data-over-cable service interface specification (DOCSIS) 2.0. The performance of the synchronization algorithms exploiting the proposed preamble structure is evaluated with various computer simulations.

关键词： cable modem synchronization algorithms CAZAC sequence

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Preamble Design and synchronization Algorithm for Cooperative Relay Systems

Preamble Design and Synchronization Algorithm for Cooperativ...

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70th IEEE Vehicular Technology Conference

作者： Cheng, Yusi Jiang, Yanxiang You, Xiaohu Southeast Univ Natl Mobile Commun Res Lab Nanjing Peoples R China

ISBN: (纸本)9781424425143

In the cooperative relay system, different frames from different relays are not aligned in the time domain, and have different carrier frequency offsets (CFOs). Estimation of these time offsets and multiple CFOs is a crucial and challenging task. In this contribution, a new preamble structure is proposed, and the corresponding timing and frequency synchronization algorithms are also presented for the cooperative relay systems. CAZAC sequence is utilized in the preamble design regarding of its correlation properties. The performance of the proposed algorithms is evaluated by simulations. The simulation results show that the proposed preamble structure and synchronization algorithms have a satisfactory performance in cooperative relay systems.

关键词： Cooperative relay system OFDM synchronization algorithms Constant amplitude zero auto-correlation (CAZAC) sequence

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On the throughput of a resource sharing model

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MATHEMATICS OF OPERATIONS RESEARCH 2001年第1期26卷 163-173页

作者： Dumas, V Robert, P Inst Natl Rech Informat & Automat F-78153 Le Chesnay France

A stochastic model of a parallel system with synchronization constraints is analyzed from a Markovian point of view. Some ergodic properties of this model are proved. We also give bounds on the throughput using result... 详细信息

关键词： synchronization algorithms uniform ergodicity branching processes

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DISTRIBUTED SIMULATION OF DISCRETE EVENT SYSTEMS

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PROCEEDINGS OF THE IEEE 1989年第1期77卷 99-113页

作者： RIGHTER, R WALRAND, JC Dept. of Decision & Inf. Sci. Santa Clara Univ. CA

An overview of distributed simulation of discrete event systems and the issues associated with it. Alternative approaches for decomposing the simulation into tasks that can be run on separate processors are described, and the potential parallelism associated with certain kinds of decomposition is studied. Existing synchronization algorithms are discussed. An attempt is made throughout to show what decomposition approaches and synchronization algorithms may be appropriate depending on properties of the application and the multiprocessor architecture. Empirical and analytical performance studies are described, where available

关键词： control system analysis computing decomposition digital simulation discrete event systems discrete time systems distributed simulation multiprocessor architecture parallel processing synchronisation synchronization algorithms

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Synchronication for differential transmitted reference UWB receivers

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2007年第11期6卷 4154-4163页

作者： D'Amico, Antonio A. Mengali, Umberto Taponecco, Lorenzo Dept Informat Engn I-56100 Pisa Italy

This paper investigates timing recovery for differential transmitted reference (DTR) ultra-wideband receivers. In DTR systems the symbol energy is distributed over several time slots (frames) and a single pulse is transmitted per frame. The information is conveyed by differentially encoding the pulse polarities. Equal polarities correspond to a bit +1 while alternate polarities correspond to a bit -1. The detector computes the decision statistic by correlating pulses from adjacent frames and summing the contributions from all the frames of a symbol. synchronization consists in providing accurate timing for the correlation computations. A timing algorithm is proposed requiring a limited amount of circuitry in addition to that needed for detection purposes. No training sequences are needed as the synchronizer operates in a blind mode. Two possible receiver architectures are envisioned, analog or digital. The effects of the timing errors on the receiver performance are investigated by simulation. In general, they are found to be negligible, except when the implementation is digital and the analog-to-digital converter resolution is limited to 1 bit.

关键词： DTR receivers synchronization algorithms UWB systems

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Bistatic TerraSAR-X/F-SAR Spaceborne-Airborne SAR Experiment: Description, Data Processing, and Results

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2010年第2期48卷 781-794页

作者： Rodriguez-Cassola, Marc Baumgartner, Stefan V. Krieger, Gerhard Moreira, Alberto DLR German Aerosp Ctr Microwaves & Radar Inst D-82234 Oberpfaffenhofen Germany

We report about the first X-band spaceborne-airborne bistatic synthetic aperture radar (SAR) experiment, conducted early November 2007, using the German satellite TerraSAR-X as transmitter and the German Aerospace Center's (DLR) new airborne radar system F-SAR as receiver. The importance of the experiment resides in both its pioneering character and its potential to serve as a test bed for the validation of nonstationary bistatic acquisitions, novel calibration and synchronization algorithms, and advanced imaging techniques. Due to the independent operation of the transmitter and receiver, an accurate synchronization procedure was needed during processing to make high-resolution imaging feasible. Precise phase-preserving bistatic focusing can only be achieved if time and phase synchronization exist. The synchronization approach, based on the evaluation of the range histories of several reference targets, was verified through a separate analysis of the range and Doppler contributions. After successful synchronization, nonstationary focusing was performed using a bistatic backprojection algorithm. During the campaign, stand-alone TerraSAR-X monostatic as well as interoperated TerraSAR-X/F-SAR bistatic data sets were recorded. As expected, the bistatic image shows a space-variant behavior in spatial resolution and in signal-to-noise ratio. Due to the selected configuration, the bistatic image outperforms its monostatic counterpart in almost the complete imaged scene. A detailed comparison between monostatic and bistatic images is given, illustrating the complementarity of both measurements in terms of backscatter and Doppler information. The results are of fundamental importance for the development of future nonsynchronized bistatic SAR systems.

关键词： Bistatic radar bistatic SAR processing synchronization algorithms synthetic aperture radar (SAR)

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A Flexible and Scalable Affinity Lock for the Kernel 16

A Flexible and Scalable Affinity Lock for the Kernel

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16th IEEE International Conference on High Performance Computing and Communications HPCC 2014\11th IEEE International Conference on Embedded Software and Systems ICESS 2014\6th International Symposium on Cyberspace Safety and Security CSS 2014

作者： Zhang, Benlong Kang, Junbin Wo, Tianyu Wang, Yuda Yang, Renyu Beihang Univ State Key Lab Software Dev Environm Beijing Peoples R China

ISBN: (纸本)9781479961238

A number of NUMA-aware synchronization algorithms have been proposed lately to stress the scalability inefficiencies of existing locks. However their presupposed local lock granularity, a physical processor, is often not the optimum configuration for various workloads. This paper further explores the design space by taking into consideration the physical affinity between the cores within a single processor, and presents FSL to support variable and finely tuned group size for different lock contexts and instances. The new design provides a uniform model for the discussion of affinity locks and can completely subsume the previous NUMA-aware designs because they have only discussed one special case of the model. The interfaces of the new scheme are kernel-compatible and thus largely facilitate kernel incorporation. The investigation with the lock shows that an affinity lock with optimal local lock granularity can outperform its NUMA-aware counterpart by 29.40% and 58.28% at 80 cores with different workloads.

关键词： synchronization algorithms multi-core algorithms

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