Energy Interchange Research Articles

Fast Directional Energy Interchange Used in MCMC-based Autonomous Decentralized Mechanism toward a Resilient Microgrid

Fast Directional Energy Interchange Used in MCMC-based Autonomous Decentralized Mechanism toward a Resilient Microgrid

A Privacy-Preserving Distributed Wide-Area Automatic Generation Control Scheme

The increased penetration of renewable resources has made frequency regulation and generation control growing concerns for power system operators. Due to the variability of renewable resources and the reduced inertia leading to the deterioration of system frequency response, many balancing areas expect a need to increase their regulation services and non-spinning reserves. This also increases the total cost of system operation and may elevate location marginal energy prices. This article addresses the scheduling of energy interchange between balancing areas, in light of optimizing regulation services in the entire interconnected power system. A control architecture is defined to extend the existing area control error concept to allow more cooperation between interconnected balancing areas. In this scheme, regulation services from different balancing areas can be pooled such that a loss of generation in one control area can utilize regulation services from multiple areas resulting in a more economic dispatch of generation resources. The effectiveness of the wide-area control scheme is demonstrated in a large-scale testbed for two power systems with high renewable penetration.

THE BLUES AND OLDER MINORITY MUSICIANS: MORE THAN JUST MUSIC XXVI

This 26th annual symposium again showcases a world-wide musical genre in a regional setting with local performers. Texas Blues has emanated from a pantheon of talented artists beginning in the earliest days of Roots and Blues music to the present day, and Austin has become the epicenter of this talent and music. With legendary classic blues musicians from the early 2oth century to emerging younger musicians who re-energize and re-invent this uniquely American musical genre, to legendary music labels and venues like Antone’s which continue to engage blues music artists of all ages, Austin continues to be the home of Texas Blues. Lifetime Achievement Award -winning 89-year-young, Miss Lavelle White epitomizes the resilience and energy interchange of both the performer and the music, and their mutual contribution to longevity and continued engagement. Still performing after 70 years, she has influenced generations of younger prominent blues performers and continues to appear weekly at local blues mecca Antone’s along with her Grammy Award winning band and is preparing her fourth album release. This session will celebrate her music, her artistry, and her continued success as an older blues performer. A visit to a local blues venue later in the evening will allow for a true appreciation of the blues music scene in Austin.

Advanced Energy Flow Control Concept of an MMC for Unrestricted Operation as a Multiport Device

An advanced approach of the internal energy flow control of a multiport device based on a modular multilevel converter (MMC) was proposed. Such a multiport device offers various connecting points as ac terminals, the main dc terminal as well as the dc terminals of the MMC modules. State-of-the-art multiport concepts have restrictions concerning the flexibility of connecting the available ports. The proposed concept makes an unrestricted energy interchange between all ports possible without affecting the ac grid and the main dc terminal. It contains a microscopic and macroscopic view of the entire system and an analytic description in a double synchronous reference frame. This approach allows the identification of degrees of freedom for the internal energy flow control to overcome the mentioned restrictions of state-of-the-art multiport devices. Beyond numerous simulations calculations, the proposed concept has been implemented to a prototype of a multiport device which consists of an MMC with integrated batteries in power electronics laboratory. The approach has been successfully tested and verified with measurement results.

From the Relativistic Mixture of Gases to the Relativistic Cucker–Smale Flocking

We present a relativistic model for a mixture of Euler gases with multiple temperatures. For the proposed relativistic model, we explicitly determine production terms resulting from the interchange of energy–momentum between the constituents via the entropy principle. We use the analogy with the homogeneous solutions of a mixture of gases and the thermomechanical Cucker–Smale (in short TCS) flocking model in a classical setting (Ha and Ruggeri in Arch Ration Mech Anal 223:1397–1425, 2017) to derive a relativistic counterpart of the TCS model. Moreover, we employ the theory of a principal subsystem to derive the relativistic Cucker–Smale (in short CS) model. For the derived relativistic CS model, we provide a sufficient framework leading to the exponential flocking in terms of communication weights and also show that the relativistic CS model reduces to the classical CS model, as the speed of light tends to infinity in any finite-time interval.

Thermodynamic analysis of phase equilibrium and surface tension of ternary polymer solutions

AbstractThe liquid–liquid equilibrium (LLE) and surface behavior of polymer solutions were investigated. Systems of poly vinyl methyl ether (PVME)/water and polystyrene (PS)/cyclohexane were chosen as model systems because they show different types of LLE and surface behavior. Ternary polymer solutions of PVME/water/alcohol and PS/cyclohexane/alcohol were also studied. The cloud points of given systems were determined by thermo‐optical analysis method. For surface tension measurements at the air/polymer solution interface, the well‐known plate method was utilized. The investigated polymer solutions exhibit various types of LLE and surface behavior depending on the type of solvent and temperature. The modified double lattice model with chain length dependence is used for description of the phase equilibrium. To improve the interpretation of the surface behavior of the polymer solution, we developed a new thermodynamic frame work based on density gradient theory. Thermodynamic analysis was also conducted using the proposed model to provide understanding of the surface behavior. The surface energy difference and interchange energy had an important role in the driving force of the surface behavior. Utilizing the predetermined model parameters from the phase equilibrium calculation, the proposed model provides satisfactory agreement with measured surface tension data, with less than 5% error.

Scaling of decoherence and energy flow in interacting quantum spin systems

We address the quantum dynamics of a system composed of a qubit globally coupled to a many-body system characterized by short-range interactions. We employ a dynamic finite-size scaling framework to investigate the out-of-equilibrium dynamics arising from the sudden variation (turning on) of the interaction between the qubit and the many-body system, in particular when the latter is in proximity of a quantum first-order or continuous phase transition. Although the approach is quite general, we consider d-dimensional quantum Ising spin models in the presence of transverse and longitudinal fields, as paradigmatic quantum many-body systems. To characterize the out-of-equilibrium dynamics, we focus on a number of quantum-information oriented properties of the model. Namely, we concentrate on the decoherence features of the qubit, the energy interchanges among the qubit and the many-body system during the out-of-equilibrium dynamics, and the work distribution associated with the quench. The scaling behaviors predicted by the dynamic finite-size scaling theory are verified through extensive numerical computations for the one-dimensional Ising model, which reveal a fast convergence to the expected asymptotic behavior with increasing the system size.

Qualitative description of the universe in the interacting fluids scheme

In this work we present a qualitative description of the evolution of a curved universe when we consider the interacting scheme for the constituents of the dark sector. The resulting dynamics can be modeled by a set of Lotka-Volterra type equations. For this model a future singularity is allowed, therefore the cyclic behavior for the energy interchange between the components of the universe is present only at some stage of the cosmic evolution. Due to the presence of the future singularity, the model exhibits global instability.

Operation of networked multi-carrier microgrid considering demand response

PurposeMicrogrids are inclined to use renewable energy resources within the availability limits. In conventional studies, energy interchange among microgrids was not considered because of one-directional power flows. Hence, this paper aims to study the optimal day-ahead energy scheduling of a centralized networked multi-carrier microgrid (NMCMG). The energy scheduling faces new challenges by inclusion of responsive loads, integration of renewable sources (wind and solar) and interaction of multi-carrier microgrids (MCMGs).Design/methodology/approachThe optimization model is formulated as a mixed integer nonlinear programing and is solved using GAMS software. Numerical simulations are performed on a system with three MCMGs, including combined heat and power, photovoltaic arrays, wind turbines and energy storages to fulfill the required electrical and thermal load demands. In the proposed system, the MCMGs are in grid-connected mode to exchange power when required.FindingsThe proposed model is capable of minimizing the system costs by using a novel demand side management model and integrating the multiple-energy infrastructure, as well as handling the energy management of the network. Furthermore, the novel demand side management model gives more accurate optimal results. The operational performance and total cost of the NMCMG in simultaneous operation of multiple carriers has been effectively improved.Originality/valueIntroduction and modeling of the multiple energy demands within the MCMG. A novel time- and incentive-based demand side management, characterized by shifting techniques, is applied to reshape the load curve, as well as for preventing the excessive use of energy in peak hours. This paper analyzes the need to study how inclusion of multiple energy infrastructure integration and responsive load can impact the future distribution network costs.

Advantages of Minimizing Energy Exchange Instead of Energy Cost in Prosumer Microgrids

Microgrids of prosumers are a trendy approach within the smart grid concept, as a way to increase distributed renewable energy penetration within power systems in an efficient and sustainable way. Single prosumer individual management has been previously discussed in literature, usually based on economic profit optimization. In this paper, two novel approaches are proposed: firstly, a different objective function, relative to the mismatch between generated and demanded power, is tested and compared to classical objective function based on energy price, by means of a genetic algorithm method; secondly, this optimization procedure is applied to batteries’ coordinated scheduling of all the prosumers composing a community, instead of single one, which better matches the microgrid concept. These approaches are tested on a microgrid with two household prosumers, in the context of Spanish regulation for self-consumption. Results show noticeably better performance of mismatch objective function and coordinated schedule, in terms of self-consumption and self-sufficiency rates, power and energy interchanges with the main grid, battery degradation and even economic benefits.

Mysterium tremendum: el sacrifi cio humano como motivo literario en la narrativa latinoamericana contemporánea

The aim of this article is twofold: firstly, it examines the meaning and the role of the frightening Aztec ritual of human sacrifice in its original religious and political context. Human sacrifice was an integral part of the Aztec world view. It facilitated the communication between the supernatural forces and the human world through the interchange of vital energy. Human sacrifice also had a political meaning, as over time it intensified and was transformed into a formidable display of state power. Secondly, the article investigates the use of human sacrifice as a literary motif in modern Latin-American prose fiction. The selected examples illustrate how the Aztec ritual has acquired different connotative values, distant from its original denotation. It has been transformed into a symbol of historical violence, existential fears and irrational reality.

Quantum Equivalence of Information, Matter and Energy: E =i mc2 *

The universe as the spacetime unity of all its parts (beings) is a selfrealizing information with the quantum resonance feedback formula E =i mc2 of mass, energy and information. Being is a basic part of triune biocosmos whose quintessence is life, i.e. the informational interchange of matter and energy among directly or indirectly visible particles of universe. Information rays fulfill whole four-dimensional space-time (information pattern field) that allowed them to pass through it without obstacles and interact with matter and energy. In extreme cold quantum physics suddenly becomes visible when all moving cosmic particles cease, what only man can describe. For eample the individual mirror image (informgraph) of man is a local result of resonance of information field on bidirectional information rays, which now we can see and even photography! The observing beings detect not only light, but first of all the information rays coming from any object and moving in any direction not being restricted, what e.g. happens with light or language. The mirror picture does not contain a single human atom, because it is only the resonating information field (Figure1).

Thermal cycling leads grains to more homogeneous force networks and energy repartition

With the help of molecular dynamics simulations of a realistic granular system, here it is first reported that thermal cycling is able to induce the total system energy to be reallocated to grains, and this makes grains gradually evolve to the energy equilibrium, especially under larger cyclic temperatures. At the same time, the stress in force chains (and on grains) will also get much relieved, and this does not need the decrease in applied pressure. Consequently, the statistical probability distribution of both internal particle forces and energy will become narrower around the most likely value, and their spatial distribution will also become more and more homogeneous. The primary cause behind the above phenomena is that grains within the initial granular system are not in sufficient energy equilibrium, and they were rearranged by thermal excitations to a new steadier packing where grains are closer to energy equilibrium. Besides, it was also observed that for the macroscopic-scale grains, the internal particle energy distribution within the granular system obeys a more general Maxwell-Boltzmann (M-B) distribution which has a more uniform distribution profile than the classical M-B distribution for gases, suggesting that the direct-contact collision may be a more effective channel for the energy interchange between particles than the indirect-contact collision. The results showed here demonstrate that more homogeneous energy reallocations may be a universal phenomenon for granular matter and may have important practical implications for the handling of granular materials.

Optimal management of multiple heat sources in a residential area by an energy management system

An energy management system (EMS) that achieves optimal operation by combining heat sources with different characteristics and using energy interchanges between residential dwellings was developed. Commercial fuel cell combined heat and power (FC-CHP) systems and CO2 heat pump water heaters (CO2HP) with high generation efficiencies have penetrated the Japanese residential market. In this real environment, the types or models of the installed heat sources vary between residential dwellings, and their energy demand is unknown. The EMS predicts energy generation and consumption and develops an optimum operational strategy that it uses to control energy equipment. It also continually revises the strategy and adjusts equipment controls to reflect actual conditions. The EMS is evaluated using a case study of a group of four residential dwellings with two different heat sources. Subsequent quantitative analysis shows that the EMS reduced energy costs by 10%. A sensitivity analysis also confirmed that it operates optimally even when energy prices are changed.

White Light Emission from Cucurbituril-Based Host-Guest Interaction in the Solid State: New Function of the Macrocyclic Host.

Energy transfer and interchange are central for fabricating white light-emitting organic materials. However, increasing the efficiency of light energy transfer remains a considerable challenge because of the occurrence of "cross talk". In this work, by exploiting the unique photophysical properties of cucurbituril-triggered host-guest interactions, the two complementary luminescent colors blue and yellow for white light emission were independently obtained from a single fluorophore dye rather than energy transfer. Further study suggested that the rigid cavity of cucurbiturils efficiently prevented the aggregation of the dye and improved its thermal stability in the solid state by providing a regular nanosized fence for each encapsulated dye molecule. As a result, a novel macrocycle-assisted supramolecular approach for obtaining solid, white light-emitting organic materials with low cost, high efficiency, and easy scale-up was successfully demonstrated.

Modelagem e simulação da marcha protética usando modelo em 3D de uma prótese transtibial

O número de amputados no mundo, incluída a Colômbia, é de mais de dez milhões de pessoas, sendo a amputação abaixo do joelho, ou amputação transtibial, bastante recorrente. Devido às mudanças siológicas que se apresentam nos amputados transtibiais, a mecânica da marcha vê-se alterada e pode chegar a afetar signi cativamente a mobilidade do sujeito. Com o objetivo de conhecer o comportamento dinâmico dos amputados transtibiais, e gerar conhecimento para entender a conduta biomecânica deles e assim ajudar no processo de reabilitação física destes sujeitos, se propôs estudar a marcha protética desde simulações geradas de um modelo computacional. Para isso, construiu-se um modelo da marcha humana fazendo uso do intercâmbio de energia que se apresenta neste movimento, empregando a análise de Lagrange. Também se obteve a modelagem matemática (diagrama de bloques) de uma prótese transtibial ativa a partir do desenho em 3D realizado no software Solidworks®; este modelo se processou em Matlab® com o objetivo de emular o uso da prótese. No modelo da marcha normal obtido se substituiu uma das pernas pelo modelo da prótese para observar a marcha protética. Os resultados do modelo tanto em valores dos rangos articulares quanto em parâmetros espaço-temporais se encontram acordes com o observado em outros estudos. A análise cinemática do comportamento do modelo mostra que a prótese proporciona suporte o corpo e permite a marcha em ausência do segmento corporal, devido a que os dados obtidos pelo modelo de patrão da marcha concordam com os dados existentes em literatura. Esta proposta de simulação é uma ajuda para assegurar a aprendizagem do estudante e do médico respeito ao comportamento biomecânico da marcha protética, uma vez que nos últimos anos se tem visto e comprovado a utilidade do uso generalizado de simulações no âmbito médico.

A-63 既成市街地における建物間エネルギー融通に関する研究 : 簡易検討モデルの開発および検討結果

A-63 既成市街地における建物間エネルギー融通に関する研究 : 簡易検討モデルの開発および検討結果

B-51 既成市街地における分散型電源を用いた建物間エネルギー融通に関する研究 : 横浜市新横浜地区における実例検証

B-51 既成市街地における分散型電源を用いた建物間エネルギー融通に関する研究 : 横浜市新横浜地区における実例検証

A Study of Total Transient Energy During the Fault Period

The total transient energy accumulated during the fault period is an important factor affecting power system dynamics. In this paper, we present a study of the total transient energy. First, we analyze the characteristics of energy interchange during the fault period. Then, an expression is developed based on characteristics analysis to estimate the total transient energy. Such an expression allows us to study how a fault, in terms of its magnitude, clearing time, and location, affects the total transient energy. Especially, the distribution factors of the total transient energy are defined based upon the expression to analyze the impact of fault location. It is found that for a fault with the given magnitude and clearing time, the total amount of total transient energy mainly depends on the difference in the distribution factors. Furthermore, it is found that the distribution factors can be applied to the identification of potential critical fault locations, the identification of coherent generators, and the identification of critical generators. The analysis results and their applications are demonstrated in the IEEE 9-bus system and the IEEE 39-bus system.

A modeling methodology for designing agents networks using timed hybrid Petri nets

This paper presents a modeling methodology for designing networked agents systems. It focuses on the agent hybrid state representation, its dynamic behavior, and its interaction with neighbor agents. The agent’s internal state as well as the communication interface between agents is modeled using timed hybrid Petri nets. The methodology is illustrated through the modeling of a case study related to energy interchange networks. The simulation of the case study model is included to illustrate the advantages the proposed methodology.