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17th IEEE International workshop on Signal Processing Advances in Wireless Communications (SPAWC)

作者： Yu, Jia thompson, John Univ Edinburgh Inst Digital Commun Edinburgh EH8 9YL Midlothian Scotland

ISBN: (纸本)9781509017492

this paper considers mixture density estimation in an asynchronous sensor networks in a distributed manner. In the statistical literature, the maximum likelihood (AIL) estimate of mixture distributions can be computed via a straightforward application of the expectation and maximization (EM) algorithm. In a random sensor networks, data are required to collected and processed at local decentralized processing units. Reformulations of standard EM-type algorithms are necessary to accommodate the characteristics of sensor networks. Existing works on the distributed EM implementation focus mainly on synchronous network. Here, we address the issue of asynchronous behaviors by proposing a diffusion-based EM gradient algorithm that updates estimates under ACC diffusion strategy. simulation results show the robustness and scalability of the proposed approach in the presence of additional randomness of asynchronous events.

关键词： sensor networks expectation and maximization (EM) algorithm asynchronous network distributed processing Gaussian mixtures

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Blind distributed Beamforming via Matrix Completion 17

Blind Distributed Beamforming via Matrix Completion

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17th IEEE International workshop on Signal Processing Advances in Wireless Communications (SPAWC)

作者： Vlachos, Evangelos Berberidis, Kostas Univ Patras Comp Technol Inst Patras 26500 Greece Univ Patras Press Diophantus Patras 26500 Greece Univ Patras Dept Comp Engn & Informat Patras 26500 Greece

ISBN: (纸本)9781509017492

In this paper, we consider the problem of distributed beamforming for maximization of the receiver signal-to-noise-ratio (SNR) subject to a total transmit power constraint. We investigate the case where the optimal beamforming weights are expressed based on the second-order statistics of the involved channels, while the communication among the relays is interference-limited. In this context, we propose a relay-cooperative scheme for interference minimization, where only a limited number of correlation quantities are sent to the fusion center (FC). We propose a technique which overcomes the problem of the incomplete covariance matrices via matrix completion. through simulation results, we show that, after a number of iterations, the proposed technique converges to the true covariance matrices and thus the optimal beamformer may be computed.

关键词： Covariance matrix

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In-place query driven big data platform: Applications to post processing of environmental monitoring

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CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE 2017年第13期29卷

作者： Lee, Jen-Gaw Tsai, Whey-Fone Lee, Lung-Cheng Lin, Ching-Yao Lin, Hsi-Ching Tsuang, Ben-Jei NARL Natl Ctr High Performance Comp 7R&D 6th RdHsinchu Sci Pk Hsinchu 300 Taiwan Natl Chung Hsing Univ Taichung Taiwan

this paper describes the use of an experimental big data platform for applications of environmental monitoring associated with visualization of global climate forecast data and air quality model simulation and response. Environmental monitoring in general requires both capabilities of model simulation for forecast, and data processing for visualization and analyses. the in-place query driven big data platform, based on concepts of Query Driven Visualization and shared-nothing distributed database, thus is developed for the need. the system architecture of this experimental big data platform entails one master data node and 17 slave data nodes, while the system links to the National Center for High-performance Computing supercomputer, Advanced Large-scale parallel Supercluster, and storage pool. For software implementation, the openSUSE operating system and MariaDB database are installed on all nodes. the master data node is responsible for metadata management and information integration and the 17 slave data nodes for distributed database and parallel model simulation, data visualization, and analyses. the application of global climate data visualization (Outgoing Longwave Radiation or OLR, temperature, rainfall, etc.) in the platform serves first to partition Network Common Data Form file data into shared-nothing distributed databases for partial visualization in slave data nodes, then integrated into whole visualization in the master node through Message Passing Interface communication. For the application of air quality management, we first accessed Taiwan Environmental Protection Administration (EPA) observed data in the master node. EPA observed data are replicated to distributed databases in slave nodes;and the air pollution model, Gaussian plume trajectory model, is replicated in all slave nodes for model simulation, which produces output data and associated image files in the local file system. the master node is able to collect whole image files through the

关键词： air pollution big data platform climate model distributed database in-place computing parallel visualization

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Impact of PV Inverter Penetration on Voltage Profile and Power Loss in Medium Voltage Distribution Systems 17

Impact of PV Inverter Penetration on Voltage Profile and Pow...

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17th IEEE workshop on Control and Modeling for Power Electronics (COMPEL)

作者： Tang, Ye Burgos, Rolando Li, Chi Boroyevich, Dushan Virginia Polytech Inst & State Univ Ctr Power Elect Syst Blacksburg VA USA

ISBN: (纸本)9781509018154

With an increasing number of PV generators at the distribution system, the impact on the distribution system is no longer negligible. A comparison is done among PV generators of different capacities, different injection locations and different reactive power control modes, for their impact on system voltage profile and power loss. Voltage sensitivity analysis is conducted to assess the impact of PV injection on system voltage profile. the accuracy of these sensitivity indices are proven by calculation results from MATLAB and simulation results from PSS/E. Guidelines are formed for utility to manage PV injection locations and regulate PV generator reactive power control to avoid voltage profile problem and reduce power loss. In comparing different PV injection locations, there's tradeoff between voltage regulation and power loss minimization, and randomly distributed PV may increase or decrease system power loss, but optimally distributed PV generators decrease power loss compared to centralized PV.

关键词： distributed PV distribution system photovoltaic (PV) power loss reactive power control sensitivity matrix voltage profile

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An Adaptive Droop Control Method for Balancing the SoC of distributed Batteries in AC Microgrids 17

An Adaptive Droop Control Method for Balancing the SoC of Di...

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17th IEEE workshop on Control and Modeling for Power Electronics (COMPEL)

作者： Gkavanoudis, Spyros I. Oureilidis, Konstantinos O. Demoulias, Charis S. AUTH Dept Elect & Comp Engn Elect Machines Lab Thessaloniki Greece

ISBN: (纸本)9781509018154

this paper proposes a new multi-segment adaptive droop control method, applied in islanded AC microgrids with distributed energy storage systems (DESSs) and hybrid PV/Battery units, for balancing their state of charge (SoC). the power/frequency characteristic curves are adjusted locally in real-time, based on the SoC level of the respective battery. Aim of the control is to maintain a comparable number of charging/discharging cycles among the batteries, while preserving the power balance in the islanded microgrid. the control strategies are implemented in each battery without relying on communications or a central management algorithm. the microgrid frequency is used as communication parameter in order to adjust the charging/discharging rate of each storage system. Detailed simulation results verify the effectiveness of this method in an islanded microgrid consisting of several loads, powered by PVs, hybrid PV/Battery units and DESSs.

关键词： microgrids three-phase converter single-phase converter microgrid impedance loss reduction

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A Design Methodology for Class-D Resonant Rectifier with parallel LC Tank 17

A Design Methodology for Class-D Resonant Rectifier with Par...

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17th IEEE workshop on Control and Modeling for Power Electronics (COMPEL)

作者： Park, Sanghyeon Rivas-Davila, Juan Stanford Univ Elect Engn Stanford CA 94305 USA

ISBN: (纸本)9781509018154

this paper presents a design methodology for the tuning of a class-D half-wave resonant rectifier with a parallel LC resonant tank input network. Class-D resonant rectifiers offer numerous advantages at high operating frequencies that are leveraged here in the design of a high-voltage rectifier. the absence of a systematic design process, however, has been a limiting factor. Designers have been relying largely on parametric variation during transient simulation to design a rectifier with resistive input impedance at the fundamental frequency of operation. In this paper, we propose a systematic design procedure that begins with universal design curves applicable to any rectifier design of this topology. this is followed by parameter selection and a convergence check that ensures the rectifier operates with the desired output voltage. Experimental results confirm the validity of the design method for both linear and nonlinear resonant capacitances. Based on the outlined procedure, a 25 MHz 500 V rectifier with resistive input impedance is designed and experimentally verified.

关键词： Design

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Improved parallel Operation Mode Control of parallel Connected 12-Pulse thyristor Dual Converter for Urban Railway Power Substations 17

Improved Parallel Operation Mode Control of Parallel Connect...

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17th IEEE workshop on Control and Modeling for Power Electronics (COMPEL)

作者： Kim, Sung-An Han, Sung-Wo Byun, Sang-In Cho, Yun-Hyun Dong A Univ Dept Elect Engn Busan South Korea R&D Ctr Busan Transportat Corp Busan South Korea

ISBN: (纸本)9781509018154

parallel-connected 12-pulse thyristor dual converters are connected to the up/down trolley line in urban power substations. When there are high-traffic trains on the up trolley line or the down trolley line, the electric energy, i.e., energy consumed and regenerative energy, increases. During this time, two converters are connected in parallel to supply power or feed energy back to the distribution grid. A parallel operation control scheme has two operating modes depending on the energy flow of trains. When the energy is less than the rated power of a converter, only one converter operates in a single operation mode. If the energy exceeds the rated power of a converter, the other converter is operated in parallel mode operation to distribute the excess energy. During the switching from the single operation mode to the parallel operation mode, overshoots and undershoots occur in the DC trolley voltage and current of each converter due to the large error in the PI controller. To solve these problems, this study proposes improved control method to prevent large overshoots and undershoots. the effectiveness of this proposed control is verified by simulation and experiment based on the comparison of the performance of conventional and proposed control method.

关键词： thyristor dual converter parallel operation mode control DC voltage control parallel current control urban railway power substation

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Multi-Stream distributed Co-Phasing: Design and Analysis 17

Multi-Stream Distributed Co-Phasing: Design and Analysis

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17th IEEE International workshop on Signal Processing Advances in Wireless Communications (SPAWC)

作者： Chopra, Ribhu Murthy, Chandra R. Annavajjala, Ramesh Indian Inst Sci Bangalore Karnataka India Charles Stark Draper Lab Cambridge MA USA

ISBN: (纸本)9781509017492

In this paper, we develop and analyze a distributed co-phasing technique for physical layer fusion of common data across a wireless sensor network using multi stream communication, when the fusion center (FC) is equipped with multiple receive antennas. In this two-phase scheme, sensors first estimate their respective channels to the FC antennas by using pilots transmitted by the FC;following which they simultaneously transmit multiple streams of data symbols by pre-rotating them according to the estimated channel phases to the different receive antennas. the mutual information between transmit nodes and the FC is presented, which helps to quantify the gains obtainable by multi stream communication. In order to aid data detection at the receiver, we propose an iterative blind channel estimation algorithm at the FC. It is found using simulations that the proposed blind channel estimation algorithm achieves a symbol error probability (SEP) close to that with perfect channel state information (CSI) at the FC. the SEP of the proposed scheme is theoretically analyzed. the system performance is evaluated via numerical simulation and is observed to be in close agreement with the derived expressions.

关键词： distributed co-phasing data fusion MIMO blind channel estimation

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Stabilization Effect of Virtual Synchronous Generators in Microgrids with Highly Penetrated Renewable Energies 17

Stabilization Effect of Virtual Synchronous Generators in Mi...

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17th IEEE workshop on Control and Modeling for Power Electronics (COMPEL)

作者： Hirase, Y. Abe, K. Noro, O. Sugimoto, K. Sakimoto, K. Kawasaki Technol Co Ltd 1-1 Kawasaki Cho Akashi Hyogo 6738666 Japan Kawasaki Heavy Ind Co Ltd 1-1Kawasaki cho Akashi Hyogo 6738666 Japan

ISBN: (纸本)9781509018154

Because of the increasing use of renewable energy technology, distributed power sources and greatly varying loads can be critical factors in power system destabilization. this problem has hampered the adoption of renewable energy;thus, researchers have studied various control method types that enable an inverter to be operated as a synchronous generator (SG). Some of these methods, referred to as Virtual Synchronous Generators (VSGs), are designed to provide virtual inertia. Using VSG technology, we can decrease the introduction of fossil fuel-based power, which allows a variety of energy sources to be combined. In this study, we derived and analyzed the frequency system dynamics of microgrids, and show that a VSG expressed as a first-order equation can stabilize the frequency of a grid without causing resonance among the generators and loads. Furthermore, we derived excitation system dynamics, and observed that a VSG applying constant impedance can reduce the voltage fluctuations in the system. the results were verified in laboratory experiments and through a simulation using EMTP-RV. the simulation test results, which were generated using data acquired from an actual photovoltaic facility, indicated that the VSG could effectively suppress system deviations caused by sudden weather change.

关键词： distributed power sources excitation system frequency fluctuation grid-connected inverter low-carbon society renewable energy virtual synchronous generator

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Model Identification of Dynamic Microgrids and Controller Optimization with High Fidelity Hardware-in-the-Loop Platform 17

Model Identification of Dynamic Microgrids and Controller Op...

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17th IEEE workshop on Control and Modeling for Power Electronics (COMPEL)

作者： Fonkwe, Edwin Kirtley, James Almeida, Murilo Medjo, Danilo MIT Dept Elect Engn & Comp Sci Cambridge MA 02139 USA Typhoon HIL Inc 35 Medford StSuite 305 Somerville MA 02143 USA

ISBN: (纸本)9781509018154

We describe a framework for model identification and model order reduction (MOR) of highly dynamic microgrids based on a high fidelity hardware-in-the-loop (HIL) platform. A synchronous generator that is connected in different configurations is analyzed to analytically obtain small-signal linearized models which are compared against HIL-obtained data. the framework is applied to a small microgrid consisting of a synchronous generator, inverter-based distributed energy resource (DER), and linear loads, and provides insights into the estimated machine transfer functions. We propose that HIL based framework could be a suitable tool for model identification, MOR, and controller optimization of complex dynamic microgrids.

关键词： Hardware in the Loop HIL Microgrid real-time simulation testbed testing

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