Resilient IEEE802.15.4MAC Protocol for Multi-Hop Mesh Wireless Sensor Network

The success of a modern power grid system is inevitably based on the integration of a smart data exchange amid several devices in power production, transportation, dispatching and loads. For large coverage data exhange, a distributed multi-hop mesh is structured from low voltage distribution boards to the substations. Thus, being cheap, less power intake, easy set-up and operating in a free licensed spectrum, ZigBee/IEEE802.15.4 makes the most suitable wireless protocol for communicating in power grid systems. Nevertheless, IEEE802.15.4MAC protocol lacks a mechanism to enable a multi-hop mesh network with efficient energy and quality of service (QoS). Hence, in this paper, a Multi-Hop Mesh IEEE802.15.4MAC protocol is designed for a large coverage data exchange. This developed model provides a resilient network with energy efficiency and QoS. Hence, the IEEE802.15.4 super_frame_standard_structure is modified by swapping the contention_free period (CFP) and contention_access_period (CAP) for time sensitive applications. For network resilience, a Reserved_Broadcast Duration_Slot (RB_DS) is introduced in the active super_frame standard_structure as beacon_offset reference time computation. Finally, for the network performance analysis, the developed Markov chain_Model with retry and saturated traffic regime without feedback is run on NS-2 simulator. Here, the hidden terminal problem is not considered since it is assumed that all nodes can "hear" each other. The simulation results are encouraging as the developed IEEE802.15.4MAC protocol is capable of improving the time delivery delay up to 35.7%

Experimental Study of a Centralized Control Strategy of a DC Microgrid Working in Grid Connected Mode

[EN] The results concerning the integration of a set of power management strategies and serial communications for the efficient coordination of the power converters composing an experimental DC microgrid is presented. The DC microgrid operates in grid connected mode by means of an interlinking converter. The overall control is carried out by means of a centralized microgrid controller implemented on a Texas Instruments TMS320F28335 DSP. The main objectives of the applied control strategies are to ensure the extract/inject power limits established by the grid operator as well as the renewable generation limits if it is required; to devise a realistic charging procedure of the energy storage batteries as a function of the microgrid status; to manage sudden changes of the available power from the photovoltaic energy sources, of the load power demand and of the power references established by the central controller; and to implement a load shedding functionality. The experimental results demonstrate that the proposed power management methodology allows the control of the power dispatch inside the DC microgrid properly.This work has been cofinanced by the Spanish Ministry of Economy and Competitiveness (MINECO) and by the European Regional Development Fund (ERDF) under Grant ENE2015-64087-C2-2.Salas-Puente, RA.; Marzal-Romeu, S.; González-Medina, R.; Figueres Amorós, E.; Garcerá, G. (2017). Experimental Study of a Centralized Control Strategy of a DC Microgrid Working in Grid Connected Mode. Energies. 10(10):1-25. https://doi.org/10.3390/en10101627S1251010Baek, J., Choi, W., & Chae, S. (2017). Distributed Control Strategy for Autonomous Operation of Hybrid AC/DC Microgrid. Energies, 10(3), 373. doi:10.3390/en10030373Patrao, I., Figueres, E., Garcerá, G., & González-Medina, R. (2015). Microgrid architectures for low voltage distributed generation. Renewable and Sustainable Energy Reviews, 43, 415-424. doi:10.1016/j.rser.2014.11.054Ma, T., Yahoui, H., Vu, H., Siauve, N., & Morel, H. (2017). A Control Strategy of DC Building Microgrid Connected to the Neighborhood and AC Power Network. Buildings, 7(4), 42. doi:10.3390/buildings7020042Lin, P., Wang, P., Xiao, J., Wang, J., Jin, C., & Tang, Y. (2018). An Integral Droop for Transient Power Allocation and Output Impedance Shaping of Hybrid Energy Storage System in DC Microgrid. IEEE Transactions on Power Electronics, 33(7), 6262-6277. doi:10.1109/tpel.2017.2741262Kakigano, H., Miura, Y., & Ise, T. (2010). Low-Voltage Bipolar-Type DC Microgrid for Super High Quality Distribution. IEEE Transactions on Power Electronics, 25(12), 3066-3075. doi:10.1109/tpel.2010.2077682Salomonsson, D., Soder, L., & Sannino, A. (2008). An Adaptive Control System for a DC Microgrid for Data Centers. IEEE Transactions on Industry Applications, 44(6), 1910-1917. doi:10.1109/tia.2008.2006398Xu, L., & Chen, D. (2011). Control and Operation of a DC Microgrid With Variable Generation and Energy Storage. IEEE Transactions on Power Delivery, 26(4), 2513-2522. doi:10.1109/tpwrd.2011.2158456Nejabatkhah, F., & Li, Y. W. (2015). Overview of Power Management Strategies of Hybrid AC/DC Microgrid. IEEE Transactions on Power Electronics, 30(12), 7072-7089. doi:10.1109/tpel.2014.2384999Lu, X., Guerrero, J. M., Sun, K., & Vasquez, J. C. (2014). An Improved Droop Control Method for DC Microgrids Based on Low Bandwidth Communication With DC Bus Voltage Restoration and Enhanced Current Sharing Accuracy. IEEE Transactions on Power Electronics, 29(4), 1800-1812. doi:10.1109/tpel.2013.2266419Chen, D., & Xu, L. (2012). Autonomous DC Voltage Control of a DC Microgrid With Multiple Slack Terminals. IEEE Transactions on Power Systems, 27(4), 1897-1905. doi:10.1109/tpwrs.2012.2189441Guerrero, J. M., Vasquez, J. C., Matas, J., de Vicuna, L. G., & Castilla, M. (2011). Hierarchical Control of Droop-Controlled AC and DC Microgrids—A General Approach Toward Standardization. IEEE Transactions on Industrial Electronics, 58(1), 158-172. doi:10.1109/tie.2010.2066534Vasquez, J., Guerrero, J., Miret, J., Castilla, M., & Garcia de Vicuna, L. (2010). Hierarchical Control of Intelligent Microgrids. IEEE Industrial Electronics Magazine, 4(4), 23-29. doi:10.1109/mie.2010.938720Unamuno, E., & Barrena, J. A. (2015). Hybrid ac/dc microgrids—Part II: Review and classification of control strategies. Renewable and Sustainable Energy Reviews, 52, 1123-1134. doi:10.1016/j.rser.2015.07.186Feng, X., Shekhar, A., Yang, F., E. Hebner, R., & Bauer, P. (2017). Comparison of Hierarchical Control and Distributed Control for Microgrid. Electric Power Components and Systems, 45(10), 1043-1056. doi:10.1080/15325008.2017.1318982Kaur, A., Kaushal, J., & Basak, P. (2016). A review on microgrid central controller. Renewable and Sustainable Energy Reviews, 55, 338-345. doi:10.1016/j.rser.2015.10.141Wu, D., Tang, F., Dragicevic, T., Guerrero, J. M., & Vasquez, J. C. (2015). Coordinated Control Based on Bus-Signaling and Virtual Inertia for Islanded DC Microgrids. IEEE Transactions on Smart Grid, 6(6), 2627-2638. doi:10.1109/tsg.2014.2387357Shi, D., Chen, X., Wang, Z., Zhang, X., Yu, Z., Wang, X., & Bian, D. (2018). A Distributed Cooperative Control Framework for Synchronized Reconnection of a Multi-Bus Microgrid. IEEE Transactions on Smart Grid, 9(6), 6646-6655. doi:10.1109/tsg.2017.2717806Dou, C., Zhang, Z., Yue, D., & Zheng, Y. (2017). MAS-Based Hierarchical Distributed Coordinate Control Strategy of Virtual Power Source Voltage in Low-Voltage Microgrid. IEEE Access, 5, 11381-11390. doi:10.1109/access.2017.2717493Bracale, A., Caramia, P., Carpinelli, G., Mancini, E., & Mottola, F. (2015). Optimal control strategy of a DC micro grid. International Journal of Electrical Power & Energy Systems, 67, 25-38. doi:10.1016/j.ijepes.2014.11.003Yue, J., Hu, Z., Li, C., Vasquez, J. C., & Guerrero, J. M. (2017). Economic Power Schedule and Transactive Energy through an Intelligent Centralized Energy Management System for a DC Residential Distribution System. Energies, 10(7), 916. doi:10.3390/en10070916Gao, L., Liu, Y., Ren, H., & Guerrero, J. (2017). A DC Microgrid Coordinated Control Strategy Based on Integrator Current-Sharing. Energies, 10(8), 1116. doi:10.3390/en10081116Operating Instructions Valve Regulated Stationary Lead-Acid Batterieshttp://www.hoppecke-us.com/tl_files/hoppecke/Documents/HO-US/Operating_Instructions_sealed_stationary_lead_acid_batteries_en1111.pdfTAB Batterieshttp://www.tabspain.com/wp-content/uploads/informacion-tecnica/renovables/curvas-y-tablas/din-41773-y-din-41774-para-baterias-pzs.pdfZhao, J., & Dörfler, F. (2015). Distributed control and optimization in DC microgrids. Automatica, 61, 18-26. doi:10.1016/j.automatica.2015.07.015Eghtedarpour, N., & Farjah, E. (2014). Power Control and Management in a Hybrid AC/DC Microgrid. IEEE Transactions on Smart Grid, 5(3), 1494-1505. doi:10.1109/tsg.2013.2294275Installation, Commissioning and Operation Handbook for Gel-Vrla-Batterieshttp://www.sonnenschein.org/PDF%20files/GelHandbookPart2.pdfAlLee, G., & Tschudi, W. (2012). Edison Redux: 380 Vdc Brings Reliability and Efficiency to Sustainable Data Centers. IEEE Power and Energy Magazine, 10(6), 50-59. doi:10.1109/mpe.2012.2212607Aryani, D., & Song, H. (2016). Coordination Control Strategy for AC/DC Hybrid Microgrids in Stand-Alone Mode. Energies, 9(6), 469. doi:10.3390/en9060469Dragicevic, T., Guerrero, J. M., Vasquez, J. C., & Skrlec, D. (2014). Supervisory Control of an Adaptive-Droop Regulated DC Microgrid With Battery Management Capability. IEEE Transactions on Power Electronics, 29(2), 695-706. doi:10.1109/tpel.2013.2257857Tian, Y., Li, D., Tian, J., & Xia, B. (2017). State of charge estimation of lithium-ion batteries using an optimal adaptive gain nonlinear observer. Electrochimica Acta, 225, 225-234. doi:10.1016/j.electacta.2016.12.119Standard for Interconnecting Distributed Resources with Electric Power Systemshttp://fglongatt.org/OLD/Archivos/Archivos/SistGD/IEEE1547.pd

Multi-channel wireless sensor networks : protocols, design and evaluation

Pervasive systems, which are described as networked embedded systems integrated with everyday environments, are considered to have the potential to change our daily lives by creating smart surroundings and by their ubiquity, just as the Internet. In the last decade, “Wireless Sensor Networks” have appeared as one of the real-world examples of pervasive systems by combining automated sensing, embedded computing and wireless networking into tiny embedded devices.\ud A wireless sensor network typically comprises a large number of spatially distributed, tiny, battery-operated, embedded sensor devices that are networked to cooperatively collect, process, and deliver data about a phenomenon that is of interest to the users. Traditionally, wireless sensor networks have been used for monitoring applications based on low-rate data collection with low periods of operation. Current wireless sensor networks are considered to support more complex operations ranging from target tracking to health care which require efficient and timely collection of large amounts of data. Considering the low-bandwidth, low-power operation of the radios on the sensor devices, interference and contention over the wireless medium and the energy-efficiency requirements due to the battery-operated devices, fulfilling the mentioned data-collection requirements in complex applications becomes a challenging task. This thesis focuses on the efficient delivery of large amounts of data in bandwidth-limited wireless sensor networks by making use of the multi-channel capability of the sensor radios and by using optimal routing topologies. We start with experimenting the operation of the sensor radios to characterize the behavior of multi-channel communication. We propose a set of algorithms to increase the throughput and timely delivery of the data and analyze the bounds on the data collection capacity of the wireless sensor networks

Physical parameter-aware Networks-on-Chip design

PhD ThesisNetworks-on-Chip (NoCs) have been proposed as a scalable, reliable and power-efficient communication fabric for chip multiprocessors (CMPs) and multiprocessor systems-on-chip (MPSoCs). NoCs determine both the performance and the reliability of such systems, with a significant power demand that is expected to increase due to developments in both technology and architecture. In terms of architecture, an important trend in many-core systems architecture is to increase the number of cores on a chip while reducing their individual complexity. This trend increases communication power relative to computation power. Moreover, technology-wise, power-hungry wires are dominating logic as power consumers as technology scales down. For these reasons, the design of future very large scale integration (VLSI) systems is moving from being computation-centric to communication-centric. On the other hand, chip’s physical parameters integrity, especially power and thermal integrity, is crucial for reliable VLSI systems. However, guaranteeing this integrity is becoming increasingly difficult with the higher scale of integration due to increased power density and operating frequencies that result in continuously increasing temperature and voltage drops in the chip. This is a challenge that may prevent further shrinking of devices. Thus, tackling the challenge of power and thermal integrity of future many-core systems at only one level of abstraction, the chip and package design for example, is no longer sufficient to ensure the integrity of physical parameters. New designtime and run-time strategies may need to work together at different levels of abstraction, such as package, application, network, to provide the required physical parameter integrity for these large systems. This necessitates strategies that work at the level of the on-chip network with its rising power budget. This thesis proposes models, techniques and architectures to improve power and thermal integrity of Network-on-Chip (NoC)-based many-core systems. The thesis is composed of two major parts: i) minimization and modelling of power supply variations to improve power integrity; and ii) dynamic thermal adaptation to improve thermal integrity. This thesis makes four major contributions. The first is a computational model of on-chip power supply variations in NoCs. The proposed model embeds a power delivery model, an NoC activity simulator and a power model. The model is verified with SPICE simulation and employed to analyse power supply variations in synthetic and real NoC workloads. Novel observations regarding power supply noise correlation with different traffic patterns and routing algorithms are found. The second is a new application mapping strategy aiming vii to minimize power supply noise in NoCs. This is achieved by defining a new metric, switching activity density, and employing a force-based objective function that results in minimizing switching density. Significant reductions in power supply noise (PSN) are achieved with a low energy penalty. This reduction in PSN also results in a better link timing accuracy. The third contribution is a new dynamic thermal-adaptive routing strategy to effectively diffuse heat from the NoC-based threedimensional (3D) CMPs, using a dynamic programming (DP)-based distributed control architecture. Moreover, a new approach for efficient extension of two-dimensional (2D) partially-adaptive routing algorithms to 3D is presented. This approach improves three-dimensional networkon- chip (3D NoC) routing adaptivity while ensuring deadlock-freeness. Finally, the proposed thermal-adaptive routing is implemented in field-programmable gate array (FPGA), and implementation challenges, for both thermal sensing and the dynamic control architecture are addressed. The proposed routing implementation is evaluated in terms of both functionality and performance. The methodologies and architectures proposed in this thesis open a new direction for improving the power and thermal integrity of future NoC-based 2D and 3D many-core architectures

Modular, Reconfigurable, High-Energy Technology Development

The Modular, Reconfigurable High-Energy (MRHE) Technology Demonstrator project was to have been a series of ground-based demonstrations to mature critical technologies needed for in-space assembly of a highpower high-voltage modular spacecraft in low Earth orbit, enabling the development of future modular solar-powered exploration cargo-transport vehicles and infrastructure. MRHE was a project in the High Energy Space Systems (HESS) Program, within NASA's Exploration Systems Research and Technology (ESR&T) Program. NASA participants included Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), and Glenn Research Center (GRC). Contractor participants were the Boeing Phantom Works in Huntsville, AL, Lockheed Martin Advanced Technology Center in Palo Alto, CA, ENTECH, Inc. in Keller, TX, and the University of AL Huntsville (UAH). MRHE's technical objectives were to mature: (a) lightweight, efficient, high-voltage, radiation-resistant solar power generation (SPG) technologies; (b) innovative, lightweight, efficient thermal management systems; (c) efficient, 100kW-class, high-voltage power delivery systems from an SPG to an electric thruster system; (d) autonomous rendezvous and docking technology for in-space assembly of modular, reconfigurable spacecraft; (e) robotic assembly of modular space systems; and (f) modular, reconfigurable distributed avionics technologies. Maturation of these technologies was to be implemented through a series of increasingly-inclusive laboratory demonstrations that would have integrated and demonstrated two systems-of-systems: (a) the autonomous rendezvous and docking of modular spacecraft with deployable structures, robotic assembly, reconfiguration both during assembly and (b) the development and integration of an advanced thermal heat pipe and a high-voltage power delivery system with a representative lightweight high-voltage SPG array. In addition, an integrated simulation testbed would have been developed containing software models representing the technologies being matured in the laboratory demos. The testbed would have also included models for non-MRHE developed subsystems such as electric propulsion, so that end-to-end performance could have been assessed. This paper presents an overview of the MRHE Phase I activities at MSFC and its contractor partners. One of the major Phase I accomplishments is the assembly demonstration in the Lockheed Martin Advanced Technology Center (LMATC) Robot-Satellite facility, in which three robot-satellites successfully demonstrated rendezvous & docking, self-assembly, reconfiguration, adaptable GN&C, deployment, and interfaces between modules. Phase I technology maturation results from ENTECH include material recommendations for radiation hardened Stretched Lens Array (SLA) concentrator lenses, and a design concept and test results for a hi-voltage PV receiver. UAH's accomplishments include Supertube heatpipe test results, which support estimates of thermal conductivities at 30,000 times that of an equivalent silver rod. MSFC performed systems trades and developed a preliminary concept design for a 100kW-class modular reconfigurable solar electric propulsion transport vehicle, and Boeing Phantom Works in Huntsville performed assembly and rendezvous and docking trades. A concept animation video was produced by SAIC, wllich showed rendezvous and docking and SLA-square-rigger deployment in LEO

CleanTX Analysis on the Smart Grid

The utility industry in the United States has an opportunity to revolutionize its electric grid system by utilizing emerging software, hardware and wireless technologies and renewable energy sources. As electricity generation in the U.S. increases by over 30% from today’s generation of 4,100 Terawatt hours per year to a production of 5,400 Terawatt hours per year by 2030, a new type of grid is necessary to ensure reliable and quality power. The projected U.S. population increase and economic growth will require a grid that can transmit and distribute significantly more power than it does today. Known as a Smart Grid, this system enables two- way transmission of electrons and information to create a demand-response system that will optimize electricity delivery to consumers. This paper outlines the issues with the current grid infrastructure, discusses the economic advantages of the Smart Grid for both consumers and utilities, and examines the emerging technologies that will enable cleaner, more efficient and cost- effective power transmission and consumption.IC2 Institut

Resource Management in Delay Tolerant Networks and Smart Grid

In recent years, significant advances have been achieved in communication networks and electric power systems. Communication networks are developed to provide services within not only well-connected network environments such as wireless local area networks, but also challenged network environments where continuous end-to-end connections can hardly be established between information sources and destinations. Delay tolerant network (DTN) is proposed to achieve this objective by utilizing a store-carry-and-forward routing scheme. However, as the network connections in DTNs are intermittent in nature, the management of network resources such as communication bandwidth and buffer storage becomes a challenging issue. On the other hand, the smart grid is to explore information and communication technologies in electric power grids to achieve electricity delivery in a more efficient and reliable way. A high penetration level of electric vehicles and renewable power generation is expected in the future smart grid. However, the randomness of electric vehicle mobility and the intermittency of renewable power generation bring new challenges to the resources management in the smart grid, such as electric power, energy storage, and communication bandwidth management. This thesis consists of two parts. In part I, we focus on the resource management in DTNs. Specifically, we investigate data dissemination and on-demand data delivery which are two of the major data services in DTNs. Two kinds of mobile nodes are considered for the two types of services which correspond to the pedestrians and high-speed train passengers, respectively. For pedestrian nodes, the roadside wireless local area networks are used as an auxiliary communication infrastructure for data service delivery. We consider a cooperative data dissemination approach with a packet pre-downloading mechanism and propose a double-loop receiver-initiated medium access control scheme to resolve the channel contention among multiple direct/relay links and exploit the predictable traffic characteristics as a result of packet pre-downloading. For high-speed train nodes, we investigate on-demand data service delivery via a cellular/infostation integrated network. The optimal resource allocation problem is formulated by taking account of the intermittent network connectivity and multi-service demands. In order to achieve efficient resource allocation with low computational complexity, the original problem is transformed into a single-machine preemptive scheduling problem and an online resource allocation algorithm is proposed. If the link from the backbone network to an infostation is a bottleneck, a service pre-downloading algorithm is also proposed to facilitate the resource allocation. In part II, we focus on resource management in the smart grid. We first investigate the optimal energy delivery for plug-in hybrid electric vehicles via vehicle-to-grid systems. A dynamic programming formulation is established by considering the bidirectional energy flow, non-stationary energy demand, battery characteristics, and time-of-use electricity price. We prove the optimality of a state-dependent double-threshold policy based on the stochastic inventory theory. A modified backward iteration algorithm is devised for practical applications, where an exponentially weighted moving average algorithm is used to estimate the statistics of vehicle mobility and energy demand. Then, we propose a decentralized economic dispatch approach for microgrids such that the optimal decision on power generation is made by each distributed generation unit locally via multiagent coordination. To avoid a slow convergence speed of multiagent coordination, we propose a heterogeneous wireless network architecture for microgrids. Two multiagent coordination schemes are proposed for the single-stage and hierarchical operation modes, respectively. The optimal number of activated cellular communication devices is obtained based on the tradeoff between communication and generation costs