Power Grid

Recent improvements in fuel cell technology along with an increasing demand for small generator units have led to renewed interest in dispersed generation units. This work demonstrates a methodology for deploying dispersed fuel cell generators throughout a power system to allow for more efficient operation. A detailed study of the system losses and sensitivities on Eastern Washington system as part

Given a power grid modeled by a network together with equations describing the power flows, power generation and consumption, and the laws of physics, the so-called N − k problem asks whether there exists a set of k or fewer arcs whose removal will cause the system to fail. The case where k is small is of practical interest. We present theoretical and computational results involving a mixed-integer model and a continuous nonlinear model related to this question.

The transformation of the European infrastructure creates considerable system security challenges. GRID is a joint effort of six European research organizations to achieve consensus on the key issues involved by ICT related vulnerabilities of power systems in view of theses challenges. GRID has recently issued a preliminary Road Map for future research in the area, grounded on a survey on the position of the European industrial and research communities. The survey assessed the challenges raised and the research needs in this perspective. This paper reviews the conception process for the Road Map and provides motivations for the way it is structured. It also overviews the three areas of investigation of the Road Map: understanding the impact of risk and adapting society and organisations, developing risk and vulnerability assessment and upgrading control architectures. The focus is on the needs and the challenges within each area and the main objectives of the Road Map.

Consumer electricity needs to be produced because it is not an energy freely present in nature. So production happens in power plants most often generated by electromagnetic generators primarily driven by heat engines fueled by combustion or nuclear fission. Kinetic energy produced by flowing water or wind also drive generators. Tonex offers Power Grid Operation Training courses.

8 typically slower than ϳ1 km s −1 ) might differ significantly from what is assumed by current modelling efforts 27 . The expected equation-of-state differences among small bodies (ice versus rock, for instance) presents another dimension of study; having recently adapted our code for massively parallel architectures (K. M. Olson and E.A, manuscript in preparation), we are now ready to perform a more comprehensive analysis.

Leveraging the power of nowadays graphics processing units for robust power grid simulation remains a challenging task. Existing preconditioned iterative methods that require incomplete matrix factorizations can not be effectively accelerated on GPU due to its limited hardware resource as well as data parallel computing. This work presents an efficient GPU-based multigrid preconditioning algorithm for robust power grid analysis. An ELL-like sparse matrix data structure is adopted and implemented specifically for power grid analysis to assure coalesced GPU device memory access and high arithmetic intensity. By combining the fast geometrical multigrid solver with the robust Krylov-subspace iterative solver, power grid DC and transient analysis can be performed efficiently on GPU without loss of accuracy (largest errors < 0.5 mV). Unlike previous GPU-based algorithms that rely on good power grid regularities, the proposed algorithm can be applied for more general power grid structures. Experimental results show that the DC and transient analysis on GPU achieves more than 25X speedups over the best available CPU-based solvers. An industrial power grid with 10.5 million nodes can be accurately solved in 12 seconds.

Grinding mill drives play an important role in the mining industry. Almost 60% of the electrical energy consumed by modern concentrator plants goes to grinding mill drives. Different technologies are used in grinding systems presenting special characteristics from the electrical and process points of view. This paper presents a technical evaluation and practical experience of two different technologies used in high-power grinding mill drives. The analysis is focused on the static power converter and associated control scheme required to drive the motor. Cycloconverters and load-commutated inverters are analyzed in terms of power grid interaction, motor interaction, and the required control scheme. The evaluation is supported with practical results obtained in different concentrator plant facilities.

According to growth of electricity demand and the increased number of non-linear loads in power grids, providing a high quality electrical power should be considered. In this paper, voltage sag and swell of the power quality issues are studied and distributed power flow controller (DPFC) is used to mitigate the voltage deviation and improve power quality. The DPFC is a new FACTS device, which its structure is similar to unified power flow controller (UPFC). In spite of UPFC, in DPFC the common dc-link between the shunt and series converters is eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. The case study contains a DPFC sited in a single-machine infinite bus power system including two parallel transmission lines, which simulated in MATLAB/Simulink environment. The presented simulation results validate the DPFC ability to improve the power quality.

This paper addresses a forensic tool used to assess audio authenticity. The proposed method is based on detecting phase discontinuity of the power grid signal; this signal, referred to as electric network frequency (ENF), is sometimes embedded in audio signals when the recording is carried out with the equipment connected to an electrical outlet or when certain microphones are in an ENF magnetic field. After down-sampling and band-filtering the audio around the nominal value of the ENF, the result can be considered a single tone such that a high-precision Fourier analysis can be used to estimate its phase. The estimated phase provides a visual aid to locating editing points (signalled by abrupt phase changes) and inferring the type of audio editing (insertion or removal of audio segments). From the estimated values, a feature is used to quantify the discontinuity of the ENF phase, allowing an automatic decision concerning the authenticity of the audio evidence. The theoretical background is presented along with practical implementation issues related to the proposed technique, whose performance is evaluated on digitally edited audio signals.

Future studies of episodic processes in the ocean and earth will require new tools to complement traditional, ship-based, expeditionary science. This will be enabled through the construction of innovative facilities called ocean observatories which provide unprecedented amounts of power and two-way bandwidth to access and control instrument networks in the oceans. The most capable ocean observatories are designed around a submarine fiber optic/power cable connecting one or more seafloor science nodes to the terrestrial power grid and communications backhaul. This paper defines the top level requirements that drive cabled observatory design and the system engineering environment within which a scientifically-capable infrastructure can be implemented. Commercial high reliability submarine telecommunication technologies which will be crucial in the design of long term cabled observatories are then reviewed. The top level architecture of a generic cabled observatory, describing the main subsystems comprising the whole and defining technological approaches to their engineering, is then described, along with some example design choices and tradeoff studies.

One of the missions of the North American Syn-chroPhasor Initiative (NASPI) is to create a robust, widely available and secure synchronized data measurement infrastructure, dubbed NASPInet, that will improve reliability of the power grid. Phasor Measurement Unit (PMU), a GPS clock synchronized measurement device capable of measuring the current and voltage phasors in the power grid, is the main measurement device that NASPInet envisions to support. While the dataflow, latency and to some extent security requirements for individual PMU applications that depend on the measurement infrastructure have been characterized, this work undertakes the challenge of characterizing the collective dataflow, latency and security requirements of the measurement infrastructure when using different network architectures and when multiple PMU applications simultaneously utilize NASPInet. For our analysis we focus on a case study where we model a scalable scenario in NASPInet for a part of the North American Power Grid, the western interconnect, using Network Simulator v2 (NS-2).

Analysis and design of on-chip power grids are complex problems. A typical grid consists of hundreds of millions of transistors that act as current consumers. Typical algorithms for power grid analysis or power grid automatic design, model the current consumers, namely the CMOS logic gates, as ideal current sources. In this study we offer a new methodology for modeling the power-consuming gates on the grid. Our approach is based on the analysis of the total dissipated power by these consumers. We propose a new model for the current consumers, based on effective impedance. In this model, only passive elements are employed. It relies on a calculation of the effective capacitance and effective resistance of the logic gates. Since during each clock period the dissipated power and the stored energy are exactly represented, total energy and power are exactly modeled. Methods from statistical/computational physics can be adopted to represent clusters of consumers on each subgrid as "macro-circuits". The interaction between the power grid and the current consumers is taken into account in this model and an example for it is presented.

BUSINESS SENSITIVE INFORMATION This document contains business sensitive and potentially patentable subject matter protectable under state and Federal law. No further dissemination is permitted without express permission of UT-Battelle, LLC. Disclosure of this document to Federal employees is made subject to 35 USC 205 and such employees are subject to 18 USC 1905 against further disclosure This manuscript has been authored by UT-Battelle, a contractor of the U.S. Government (USG) under Department of Energy (DOE) Contract DE-AC05-00OR22725. The USG retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for USG purposes.

Voltage instability is the main cause of concern for the large scale integration of wind power into the power grid. For the induction generator based wind generation system, the fixed capacitor located at the generator terminal can not normally cater for the reactive power demand during the transient disturbances like wind gusts and faults on the system. This paper presents two schemes for enhancing voltage stability of grid connected wind generator system. These are: variable susceptance control thru SVC and reactive power compensation through static compensator system (STATCOM). Simulation results show that both schemes are well capable of providing voltage stability and damping transient arising from reasonable level of disturbances. The STATCOM, however, demonstrates superior performance because of its fast response capability as well as its ability to provide compensation independent of system voltage support.

HISTORICAL crossroads. Decisions must soon be made about the direction of grid development so that it can meet extraordinary economic challenges, critical needs for energy security, and essential requirements for a sustainable way of life. This is a defi ning moment in terms of our nation's commitment to providing an electric energy system, including a bulk transmission network, that can meet the societal needs of the 21st century and beyond. A major evolutionary step in the grid's design, planning, and operation is needed, one that adopts new design concepts and innovative technologies that can be integrated into a modern infrastructure. The American Recovery and Reinvestment Act of 2009 (ARRA) provided a number of opportunities to achieve these far-reaching objectives. This article describes a vision of-and the steps needed to reach-the national objective of having a smart grid infrastructure. Our focus is on new concepts and related technological considerations in developing smart grid solutions that will meet the seven objectives of the smart grid, as identifi ed by the U.S. Department of Energy (DOE): 1) enabling informed participation by customers 2) accommodating all generation and storage options 3) enabling new products, services, and markets 4) providing the level of power quality required to meet the full range of needs in the 21stcentury economy 5) optimizing asset utilization and operating efficiently 6) addressing disturbances through automated prevention, containment, and restoration 7) operating resiliently against all hazards. To achieve these goals, smart research and development efforts must harmonize four principal aspects of the future grid: ✔ Expansion of the electricity grid infrastructure: This includes building new infrastructure to replace aging infrastructure while expanding grid capacity, improving the operation and efficiency of the existing infrastructure, and developing novel concepts, technologies, and applications. The smart grid will integrate renewable generation and distributed energy sources. It will also enable creative options for customers to participate in system operations by offering their loads and storage capability (e.g., from plugin hybrid electric vehicles) as resources. Customers also want options for making their own usage more energy and cost efficient (such as through building energy management systems).

The smart grid idea was implemented as a new approach to the traditional power grid to find an optimal way to integrate renewable and sustainable energy innovations. In such a manner the web-connected advanced grid, often known as the power web, also appears as a unique approach at a certain time to make sure electricity from everywhere. Such innovations are primarily aimed at building a successful community. Smart Grids are an expanding technology that offers dramatic socioeconomic improvements. Data protection problems in power data usage and trading, nevertheless, pose significant obstacles in smart grid implementation. Blockchain technology has been tested for scope in the advanced grid to overcome such hurdles. Blockchain has some fantastic features that make it a successful smart grid model framework. This paper illustrates a detailed study of the smart grid implementation of Blockchain. The major security issues in smart grid environments that Blockchain can tackle is described.

Like any other industry sector, the electrical power industry is facing challenges involved with the increasing demand for interconnected system operations and control under the restructured electrical industry due to deregulation of the electrical market and the trend of the Smart Grid . This moves automation networks from outdated, proprietary, closed networks to the more current arena of Information Technology (IT). However, while gaining all of the cost and performance benefits of IT, existing IT security challenges are acquired as well. The power grid automation network has inherent security risks due to the fact that the systems and applications in the network were not originally designed for the general IT environment. In this paper, we propose a conceptual layered framework for protecting power grid automation systems against cyber attacks. The following factors are taken into account: 1) integration with existing, legacy systems in a non-intrusive fashion; 2) desirable performance in terms of modularity, scalability, extendibility, and manageability; 3) alignment to the "Roadmap to Secure Control Systems in the Energy Sector" and the future intelligent power delivery systems . The on-site test result of the system prototype is briefly presented as well.

The “smart grid” refers to various efforts to modernize the power grid through the application of alternate sources of energy and intelligent devices. The present national interest in smart grid applications has generated many questions concerning the role of distribution engineering in the future. What features do utility engineers need in distribution system analysis tools to support the future smart grid? This paper will discuss some relevant Electric Power Research Institute research in this area that focuses on selected issues related to smart grid analysis relevant to rural utilities. The essential characteristics of distribution system analysis tools to support analysis of these issues are discussed.

Hydrogen gas is thought to be the ideal fuel for a world in which air pollution has been alleviated, global warming has been arrested, and the environment has been protected in an economically sustainable manner. Hydrogen and electricity could team to provide attractive options in transportation and power generation. Interconversion between these two forms of energy suggests on-site utilization of hydrogen to generate electricity, with the electrical power grid serving in energy transportation, distribution utilization, and hydrogen regeneration as needed. A challenging problem in establishing H 2 as a source of energy for the future is the renewable and environmentally friendly generation of large quantities of H 2 gas. Thus, processes that are presently conceptual in nature, or at a developmental stage in the laboratory, need to be encouraged, tested for feasibility, and otherwise applied toward commercialization.

Nowadays population growth and increase of land cost have made it inevitable for the cities to construct tall building or vertical development or growth. Among the advantages of vertical expansion of the cities are saving cultivable land to supply needed food for increasing population, reducing environmental destruction due to reduced construction on natural land, reduce in transportation and urban traffic as well as reduce in energy consumption and air pollution caused by horizontal expansion of the cities. This paper examines relationship between high-performance tall building architecture and environment applying innovative technology. Research method of present investigation is descriptive. It is concluded that the future of the built environment depends on the methods and techniques used by engineers and architects to design sustainable environment and intelligent building.

Humans globally consume roughly 15,000 gigawatts (GW) of power, in oil, coal, gas, nuclear, and renewables all added together. To put it
another way, it means that, on average, we use 15,000 gigajoules (GJ) of energy every second of every day. That is an enormous number, equivalent to switching on 15 billion electric kettles.

In a practical power system, automating all the substations is neither affordable nor economically justifiable. On the other hand, the trend for electric power subsidies elimination in some regions, such as Iran, aggravates this situation. To enhance the cost effectiveness of distribution automation system, this paper proposes a novel applicable qualitative-quantitative method using analytical hierarchical process (AHP) to find the optimum placement of remote terminal units (RTU). Entire attempt is to contribute all the crucial technical and practical parameters related to this problem in order to find the most reliable solution. Optimum number of RTUs is determined using the concepts of reliability cost/worth taking into account the total cost of customer interruption and investment cost of RTUs. The effectiveness of the proposed technique is validated on a real distribution feeder of Iran's power grid.

Smart meter is an advanced energy meter that measures consumption of electrical energy providing additional information compared to a conventional energy meter. Integration of smart meters into electricity grid involves implementation of a variety of techniques and software, depending on the features that the situation demands. Design of a smart meter depends on the requirements of the utility company as well as the customer. This paper discusses various features and technologies that can be integrated with a smart meter. In fact, deployment of smart meters needs proper selection and implementation of a communication network satisfying the security standards of smart grid communication. This paper outlines various issues and challenges involved in design, deployment, utilization, and maintenance of the smart meter infrastructure. In addition, several applications and advantages of smart meter, in the view of future electricity market are discussed in detail. This paper explains the importance of introducing smart meters in developing countries. In addition, the status of smart metering in various countries is also illustrated.

For 100 years, there has been no change in the basic structure of the electrical power grid. Experiences have shown that the hierarchical, centrally controlled grid of the 20th Century is ill-suited to the needs of the 21st Century. To address the challenges of the existing power grid, the new concept of smart grid has emerged. The smart grid can be considered as a modern electric power grid infrastructure for enhanced efficiency and reliability through automated control, high-power converters, modern communications infrastructure, sensing and metering technologies, and modern energy management techniques based on the optimization of demand, energy and network availability, and so on. While current power systems are based on a solid information and communication infrastructure, the new smart grid needs a different and much more complex one, as its dimension is much larger. This paper addresses critical issues on smart grid technologies primarily in terms of information and communication technology (ICT) issues and opportunities. The main objective of this paper is to provide a contemporary look at the current state of the art in smart grid communications as well as to discuss the still-open research issues in this field. It is expected that this paper will provide a better understanding of the technologies, potential advantages and research challenges of the smart grid and provoke interest among the research community to further explore this promising research area.

... Small-Signal Stability Analysis of Power System Integrated with PHEVs Trishna Das and Dionysios C. Aliprantis Electrical and Computer Engineering, Iowa State University, Ames, IA 50011 Page 2. ducted on the New England-39 system with PHEVs modeled as CPL loads. ...

I ndustrialization and economic development have historically been associated with man's ability to harness natural energy resources to improve his condition. Based on this definition, two industrial revolutions occurred in the 18th and 19th centuries, where natural resources such as coal (first revolution) and petroleum (second revolution) were widely exploited to produce levels of energy far beyond what could be achieved by human or animal muscle power.

The relation between solar activities and the geomagnetic field induced currents (GIC) have been well studied in the auroral region and it usually occurs most frequently at high latitudes. However, during major geomagnetic storms, the auroral zone can extend substantially towards lower latitudes. Disturbance caused by solar activities can disrupt power grids and also increase the corrosion rate of buried natural gas pipelines. GIC are driven by the geomagnetic field induced by a geomagnetic disturbance. In this paper, we investigated the correlation between solar activities using the interplanetary magnetic field (IMF) and geomagnetic disturbance storm time (DST) index data with the telluric currents (also referred to as geomagnetic induced currents GIC) level through the disturbance pattern of geomagnetic field. The research areas are from Lunas in Kedah to Perlis. The pattern of geomagnetic field disturbance had been identified and analyzed to investigate the harmful effect of geomagnetic storms towards the performance of complex power grid in Malaysia.

The development of superconducting systems for electric power is driven by the promise of improved efficiency, smaller size, and reduced weight as compared to existing technologies and by the possibility of new applications. Superconducting power components can also contribute to improved power quality and increased system reliability. This paper addresses historical developments and technology status of four superconducting power applications: cables, superconducting magnetic energy storage (SMES), fault-current limiters, and transformers. Today, SMES is the only fully functional superconducting system and it has seen only limited use at grid power levels. A few model or demonstration units exist for each of the other three applications. Superconductivity faces several hurdles on the path to widespread use. Perhaps the most important is the need for operating voltages of 100 kV or more. Though progress in this and other areas has been rapid, considerable development is needed before superconducting devices perform reliably in the utility environment. As a result, today, most initial installations are aimed at niche applications and will be installed where space is limited, where power demands are increasing over existing corridors, and/or where initial development costs can be offset by enhanced power grid performance.

8 typically slower than ϳ1 km s −1 ) might differ significantly from what is assumed by current modelling efforts 27 . The expected equation-of-state differences among small bodies (ice versus rock, for instance) presents another dimension of study; having recently adapted our code for massively parallel architectures (K. M. Olson and E.A, manuscript in preparation), we are now ready to perform a more comprehensive analysis.

In the conventional photovoltaic (PV) fed quasi-Z (qZ) network-based impedance-source-converters (ISCs), the PV array is connected to their input, whereas in the proposed topology in this paper, an additional array is paralleled to the second qZ-network's capacitor (C 2). This modification allows harvesting more PV power through full utilization of the employed qZ-network in the classical ISCs. Moreover, the proposal offers higher conversion efficiency since the current in the second qZ-network's inductor (i L2) is smaller. The voltage of the added PV array (PV 2) is independent of the voltage of the primary array (PV 1) in a wide range, which promotes tracking their maximum power points (MPPs) separatly, achieving a higher efficiency even under partial shading. The use of two separate MPPTs in one converter is a challenge since the perturbation done by the first MPPT alters the power in PV 2 as well, and vice-versa. Therefore, a two MPPs tracker (MPPsT) algorithm, which perturbs two parameters and observes four variables, is proposed for the presented converter. The theoretical analysis is validated through real-time hardware-in-the-loop tests, and it demonstrates that at least 11% more power can be harvested compared to the conventional qZ-network-based ISC.

In this paper is presented a solution for optimal operation of the Francis turbine, the most used hydro energy converter in small hydro plants. As the efficiency of this turbine is highly dependent from the water flow, which generally has a large variation, variable speed operation was chosen. Due to the fact that all hydro generators are AC machines, the connection to the 50 Hz power grid can be done only using as interface the AC/DC DC/AC static converters. For higher than 1 MW power generators, front end three level inverters are recommended. In addition, for higher than 1 kV voltage, double three level inverters shall be used, as these are allowing their connection directly to the medium voltage grid, eliminating in this way the need of separation transformers. The converter control is done by a single chip DSP controller TM3202028, which takes care of all system functions.

The integration of large amount of wind power into a power system imposes a new challenge for the secure and economic operation of the system. It is necessary to investigate the impacts of wind power generation on the dynamic behavior of the power system concerned. This paper investigates the impacts of large amount of wind power on small signal stability and the corresponding control strategies to mitigate the negative effects. The concepts of different types of wind turbine generators (WTGs) and the principles of the grid-connected structures of wind power generation systems are first briefly introduced. Then, the state-of-the-art of the studies on the impacts of WTGs on small signal stability as well as potential problems to be studied are clarified. Finally, the control strategies on WTGs to enhance power system damping characteristics are presented.

This paper provides an insight to the feasibility of adopting hydrogen as a key energy carrier and fuel source in the near future. It is shown that hydrogen has several advantages, as well as few drawbacks in using for the above purposes. The research shows that hydrogen will be a key player in storing energy that is wasted at generation stage in large-scale power grids by off-peak diversion to dummy loads. The estimations show that by the year of 2050 there will be a hydrogen demand of over 42 million metric tons or 45 billion gallon gasoline equivalent (GGE) in the United States of America alone which can fuel up 342 million light-duty vehicles for 51 × 10 11 miles (82 × 10 11 km) travel per year. The production at distributed level has also been discussed. The paper also presents the levels of risk in production, storage and distribution stages and proposes possible techniques to address safety issues. It is shown that the storage in small to medium scale containers is much economical compared to doing the same at largescale containers. The study concludes that hydrogen has a promising future to be a highly feasible energy carrier and energy source itself at consumer level.

Distributed generation (DG) units are commonly interfaced to the grid by using voltage-source inverters (VSI's). Extension of the control of these inverters allows to improve the power quality if the main power grid is disturbed or disconnected. In this paper, a control technique is developed for a VSI working in island mode. The control technique is designed in the time domain, combining an inner current control loop with an outer voltage control loop. Voltage regulation under various linear and non-linear load disturbances is studied.

This paper provides a comprehensive state-of-the-art overview on power infrastructure defense systems. A review of the literature on the subjects of critical infrastructures, threats to the power grids, defense system concepts, and the special protection systems is reported. The proposed Strategic Power Infrastructure Defense (SPID) system methodology is a real-time, wide-area, adaptive protection and control system involving the power, communication, and computer infrastructures. The SPID system performs the failure analysis, vulnerability assessment, and adaptive control actions to avoid catastrophic power outages. This paper also includes a new concept for bargaining by multiagents to identify the decision options to reduce the system vulnerability. The concept of a flexible configuration of the wide-area grid is substantiated with an area-partitioning algorithm. A 179-bus system is used to illustrate the area partitioning method that is intended to minimize the total amount of load shedding.

Phasor measurement units (PMU) coupled with high speed and bandwidth communication infrastructure holds great promise for future power system control and operation. The geographic location of the PMUs within the power system naturally affects the value added by PMUs to one specific application in power grid control and operation. Optimization of placement has been the subject of much analysis and research. This paper compares one PMU placement method targeting enhancement of state estimation accuracy with the current PMU deployment method utilized in Svenska Kraftnät (SvK), the Swedish Transmission System Operator. The possible estimation improvement applying this optimum placement algorithm is further studied while more PMUs are involved. Considering that the deployment of PMUs within SvK's grid is still limited, the study has been performed in a simulation environment. The paper contains a brief description of the simulation platform and the assumptions made during the work as well. The analysis shows that there are considerable gains to be made in estimator accuracy if the PMUs are placed in accordance with this method when compared to the current placement strategy. It could also be observed when the PMU monitored buses reaches a certain number in the entire network, the further introduction of phasor measurements will not be as effective in estimation accuracy improvement.

A grid-connected electrical phenomenon power grid or grid-connected PV power grid is electricity generating star PV power grid that's connected to the utility grid. A grid-connected PV system consists of star panels, one or many inverters, an influence acquisition unit and grid affiliation instrumentation. They vary from tiny residential and industrial upper side systems to giant utility-scale alternative energy stations. Not like complete power systems, a grid-connected system seldom includes Associate in Nursing integrated battery resolution, as they're still terribly dear. Once conditions are right, the grid-connected PV system provides the surplus power, on the far side consumption by the connected load, to the utility grid. During this paper bestowed completely different techniques used for connecting the star PV system with AC or metric weight unit grids. This paper useful for researchers and students in future for study the various techniques for star PV grid connected system.

3-D integrated circuits promise high bandwidth, low latency, low device power, and a small form factor. Increased device density and asymmetrical packaging, however, renders the design of 3-D power delivery a challenge. We investigate in this paper various methods to improve 3-D power delivery. We analyze the impact of through-silicon via (TSV) size and spacing, of controlled collapse chip connection (C4) spacing, and of dedicated power delivery TSVs. In addition to considering typical cylindrical or square metal-filled TSVs (core TSVs), we also investigate using coaxial TSVs for power delivery resulting in reduced routing blockages and added coupling capacitance. Our 3-D evaluation system is composed of a quad-core chip multiprocessor, a memory die, and an accelerator engine, and it is evaluated using representative SPEC benchmark traces. This is the first detailed architectural-level analysis for 3-D power delivery. Our findings provide clear guidelines for 3-D power delivery design. More importantly, we show that it is possible to achieve 2-D-like, or even better, power quality by increasing C4 granularity and by selecting suitable TSV size and spacing.

Modern power grid is required to become smarter in order to provide an affordable, reliable, and sustainable supply of electricity. Under such circumstances, considerable activities have been carried out in the U.S. and Europe to formulate and promote a vision for the development of the future smart power grids. However, the majority of these activities only placed emphasis on the distribution grid and demand side; while the big picture of the transmission grid in the context of smart grids is still unclear. This paper presents a unique vision for the future smart transmission grids in which the major features that these grids must have are clearly identified. In this vision, each smart transmission grid is regarded as an integrated system that functionally consists of three interactive, smart components, i.e., smart control centers, smart transmission networks, and smart substations. The features and functions of each of the three functional components as well as the enabling technologies to achieve these features and functions are discussed in detail in the paper. (S'05-M'08) received the Ph.D. degree in electrical engineering from Georgia Institute of Technology, Atlanta in 2008. Currently, he is an Assistant Professor of Electrical Engineering at the University of Nebraska-Lincoln. His research interests include renewable energy systems, power system control, stability, and performance optimization, power electronics, electric machines, FACTS devices, and the application of computational intelligence in electric energy systems. Dr.

In this paper, a two-layer network and distributed control method is proposed, where there is a top-layer communication network over a bottom-layer microgrid. The communication network consists of two subgraphs, in which the first is composed of all agents, while the second is only composed of controllable agents. The distributed control laws derived from the first subgraph guarantee the supply–demand balance, while further control laws from the second subgraph reassign the outputs of controllable distributed generators, which ensure active and reactive power are dispatched optimally. However, for reducing the number of edges in the second subgraph, generally a simpler graph instead of a fully connected graph is adopted. In this case, a near-optimal dispatch of active and reactive power can be obtained gradually, only if controllable agents on the second subgraph calculate set points iteratively according to our proposition. Finally, the method is evaluated over seven cases via simulation. The results show that the system performs as desired, even if environmental conditions and load demand fluctuate significantly. In summary, the method can rapidly respond to fluctuations resulting in optimal power sharing.

This chapter reviews the current understanding of ring current dynamics. The terrestrial ring current is an electric current flowing toroidally around the Earth, centered at the equatorial plane and at altitudes of ∼10,000 to 60,000 km. Enhancements in this current are responsible for global decreases in the Earth's surface magnetic field, which have been used to define geomagnetic storms. Intense geospace magnetic storms have severe effects on technological systems, such as disturbances or even permanent damage of telecommunication and navigation satellites, telecommunication cables, and power grids. The main carriers of the ring current are positive ions, with energies from ∼1 keV to a few hundred keV, which are trapped by the geomagnetic field and undergo an azimuthal drift. The ring current is formed by the injection of ions originating in the solar wind and the terrestrial ionosphere into the inner magnetosphere. The injection process involves electric fields, associated with enhanced magnetospheric convection and/or magnetospheric substorms. The quiescent ring current is carried mainly by protons of predominantly solar wind origin, while active processes in geospace tend to increase the abundance (both absolute and relative) of O + ions, which are of ionospheric origin. During intense geospace magnetic storms, the O + abundance increases dramatically. This increase has been observed to occur concurrently with the rapid intensification of the ring current in the storm main phase and to result in O + dominance around storm maximum. This compositional change can affect several dynamic processes, such as species-and energy-dependent charge-exchange and wave-particle scattering loss.

We extend the WITCH model to consider the possibility to produce and trade electricity generated by large scale concentrated solar power plants in highly productive areas that are connected to the demand centres through High Voltage Direct Current (HVDC) cables. We find that it becomes optimal to produce with this source only from 2040 and trade from 2050. In the second half of the century, CSP electricity shares become very significant especially when penetration limits are imposed on nuclear power and on carbon capture and storage operations (CCS). Climate policy costs can be reduced by large percentages, up to 66% with respect to corresponding scenarios without the CSP-powered Super-Grid option and with limits on nuclear power and CCS. We also show that MENA countries have the incentive to form a cartel to sell electricity to Europe at a price higher than the marginal cost. Therefore we advocate the institution of an international agency with the role to regulate a hypothetic Mediterranean electricity market.