Next-generation Grid Research Articles

Privacy-Preserving Data Aggregation with Dynamic Billing in Fog-Based Smart Grid

As the next-generation grid, the smart grid (SG) can significantly enhance the reliability, flexibility as well as efficiency of electricity services. To address latency and bandwidth issues during data analysis, there have been attempts to introduce fog computing (FC) in SG. However, fog computing-based smart grid (FCSG) face serious challenges in security and privacy. In this paper, we propose a privacy-preserving data aggregation scheme that supports dynamic billing and arbitration, named PPDB. Specifically, we design a four-layer data aggregation framework which uses fog nodes (FNs) to collect and aggregate electricity consumption data encrypted under the ElGamal cryptosystem and employ distributed decryption to achieve fine-grained access and bills generation based on real-time prices. In addition, we introduce a trusted third party to arbitrate disputed bills. Detailed security analysis proves that the proposed PPDB can guarantee the confidentiality, authentication and integrity of data. Compared with related schemes, the experimental results show that the communication overhead of our scheme is reduced by at least 38%, and the computational efficiency in the billing phase is improved by at least 40 times.

An Ultrafast and Ultra-Low-Temperature Hydrogen Gas-Proton Battery.

Aqueous proton batteries are regarded as one of the most promising energy technologies for next-generation grid storage due to the distinctive merits of H+ charge carriers with small ionic radius and light weight. Various materials have been explored for aqueous proton batteries; however, their full batteries show undesirable electrochemical performance with limited rate capability and cycling stability. Here we introduce a novel aqueous proton full battery that shows remarkable rate capability, cycling stability, and ultralow temperature performance, which is driven by a hydrogen gas anode and a Prussian blue analogue cathode in a concentrated phosphoric acid electrolyte. Its operation involves hydrogen evolution/oxidation redox reactions on the anode and H+ insertion/extraction reactions on the cathode, in parallel with the ideal transfer of only H+ between these two electrodes. The fabricated aqueous hydrogen gas-proton battery exhibits an unprecedented charge/discharge capability of up to 960 C with a superior power density of 36.5 kW kg-1, along with an ultralong cycle life of over 0.35 million cycles. Furthermore, this hydrogen gas-proton battery is able to work well at an ultralow temperature of -80 °C with 54% of its room-temperature capacity and under -60 °C with a stable cycle life of 1150 cycles. This work provides new opportunities to construct aqueous proton batteries with high performance in extreme conditions for large-scale energy storage.

Hierarchical Coordinated Fast Frequency Control Using Inverter-Based Resources

The share of inverter-connected renewable energy resources (RESs) is increasing in the grid, with these resources partially displacing conventional synchronous generators. This has resulted in increased variability of active power supply, reduced overall inertia, and increased spatial heterogeneity of inertia, leading to faster system frequency dynamics along with larger and more frequent frequency control events. These effects are expected to become increasingly more important in power system control in next-generation grids, which may conceivably be made up entirely of RESs. To mitigate these challenges, a fast, area-based hierarchical control strategy is proposed. This scheme partitions the power system into small areas, estimates local power imbalances, and corrects them by utilizing local inverter-based resources (IBRs). In cases where sufficient resources are not available locally, power is preferentially sourced from electrically close neighbours using an iterative distributed optimization scheme which preserves information privacy between areas. The proposed frequency control architecture can be retrofit onto existing control systems, and allows for flexibility in the amount of model information available to the designer. The control strategy is validated on two detailed multi-area power system models. Simulation results show that the strategy provides fast and localized frequency control.

Ammonium ion intercalated hydrated vanadium pentoxide for advanced aqueous rechargeable Zn-ion batteries

Considering many factors, including environmental protection, high cost, and limited resource, aqueous rechargeable Zn-ion batteries (ARZIBs) are expected to be a new next-generation grid to replace Li-ion batteries. The open layered framework of (metal ions intercalated) hydrated vanadium pentoxides is conducive to the transfer and diffusion of zinc ions, making this kind of material a promising cathode material. In this work, ammonium ion (NH4+) intercalated hydrated vanadium pentoxide [(NH4)xV2O5·nH2O, abbreviated as NVOH] is prepared by a comparatively low-temperature synthesis and developed as a cathode material for ARZIBs. The influence of different types and concentrations of zinc salt electrolytes on the electrochemical performance is first studied, demonstrating that 3 M Zn(CF3SO3)2 shows the most excellent performance. The Zn//NVOH battery delivers superior electrochemical reversibility, a high specific capacity (372 mAh·g-1 at 0.1 A·g-1), a preeminent energy density (273 Wh·kg-1 at 155 W·kg-1), and a long lifespan cycling performance (175 mAh·g-1 after 2,000 cycles at 5 A·g-1), which is superior to or comparable to most up-to-the-minute V-based materials applied to ARZIBs. The intercalation reversibility of zinc ion is proved during the electrochemical reaction by various characteristic measurements. This work not only provides a low-temperature hydrothermal synthesis route (100 °C) for NVOH but also demonstrates that it can be a promising supplement for zinc ion batteries or other portable battery devices.

An Overview of Demand Response in Smart Grid and Optimization Techniques for Efficient Residential Appliance Scheduling Problem

Smart grid (SG) is a next-generation grid which is responsible for changing the lifestyle of modern society. It avoids the shortcomings of traditional grids by incorporating new technologies in the existing grids. In this paper, we have presented SG in detail with its features, advantages, and architecture. The demand side management techniques used in smart grid are also presented. With the wide usage of domestic appliances in homes, the residential users need to optimize the appliance scheduling strategies. These strategies require the consumer’s flexibility and awareness. Optimization of the power demand for home appliances is a challenge faced by both utility and consumers, particularly during peak hours when the consumption of electricity is on the higher side. Therefore, utility companies have introduced various time-varying incentives and dynamic pricing schemes that provides different rates of electricity at different times depending on consumption. The residential appliance scheduling problem (RASP) is the problem of scheduling appliances at appropriate periods considering the pricing schemes. The objectives of RASP are to minimize electricity cost (EC) of users, minimize the peak-to-average ratio (PAR), and improve the user satisfaction (US) level by minimizing waiting times for the appliances. Various methods have been studied for energy management in residential sectors which encourage the users to schedule their appliances efficiently. This paper aims to give an overview of optimization techniques for residential appliance scheduling. The reviewed studies are classified into classical techniques, heuristic approaches, and meta-heuristic algorithms. Based on this overview, the future research directions are proposed.

Emerging soluble organic redox materials for next-generation grid energy-storage applications

Because of their structural versatility, fast redox reactivity, high storage capacity, sustainability, and environmental friendliness, soluble organic redox molecules have emerged as materials that have potential for use in energy-storage systems. Considering these advantages, this paper reviews recent progress in implementing such materials in aqueous soluble organic redox flow batteries and organic alkali metal/air batteries. We identify and discuss major challenges associated with molecular structures, cell configurations, and electrochemical parameters. Hopefully, we provide a general guidance for the future development of soluble organic redox materials for emerging energy-storage devices used in the electricity grid.

Global Trends and Advances Towards a Smarter Grid and Smart Cities

Taking advantage of new developing technologies, power systems are being developed into smarter grids with the vision of becoming the next-generation electric grid for smart cities. Some of the emerging issues and challenges associated with the development of technologies for smarter grids and smart cities are highlighted in this special issue of the Future Internet journal.

Energy Crowdsourcing and Peer-to-Peer Energy Trading in Blockchain-Enabled Smart Grids

The power grid is rapidly transforming, and while recent grid innovations increased the utilization of advanced control methods, the next-generation grid demands technologies that enable the integration of distributed energy resources (DERs)---and consumers that both seamlessly buy and sell electricity. This paper develops an optimization model and blockchain-based architecture to manage the operation of crowdsourced energy systems (CES), with peer-to-peer (P2P) energy trading transactions. An operational model of CESs in distribution networks is presented considering various types of energy trading transactions and crowdsourcees. Then, a two-phase operation algorithm is presented: Phase I focuses on the day-ahead scheduling of generation and controllable DERs, whereas Phase II is developed for hour-ahead or real-time operation of distribution networks. The developed approach supports seamless P2P energy trading between individual prosumers and/or the utility. The presented operational model can also be used to operate islanded microgrids. The CES framework and the operation algorithm are then prototyped through an efficient blockchain implementation, namely the IBM Hyperledger Fabric. This implementation allows the system operator to manage the network users to seamlessly trade energy. Case studies and prototype illustration are provided.

Current Reference Generation Based on Next-Generation Grid Code Requirements of Grid-Tied Converters During Asymmetrical Faults

Increased penetration of converter-based power generation has enforced system operators to require ancillary services from distributed generation in order to support the grid and improve the power system stability and reliability. Recent and next-generation grid codes require asymmetrical current provision during unbalanced faults for optimal voltage support. To address this, based on the highly used flexible positive- and negative-sequence control method for current reference generation, this paper presents a general current reference strategy for asymmetrical fault control, where a direct and explicit method is proposed to calculate power references and controller gains while simultaneously complying with converter current limitation and fulfilling the next-generation grid code requirements. The proposed method is tested for three distinct asymmetrical grid faults considering the requirements for dynamic voltage support of the recently revised German grid code as well as the next-generation grid codes. It is shown that the proposed method can improve the fault ride-through performance during asymmetrical faults compared with conventional solutions and comply with modern grid code requirements in a general and flexible manner.

Integrating renewable energy in smart grid system: Architecture, virtualization and analysis

Abstract Renewable energy sources (RESs) and energy storage systems (ESSs) are the key technologies for smart grid applications and provide great opportunities to de-carbonize urban areas, regulate frequency, voltage deviations, and respond to severe time when the load exceeds the generation. Nevertheless, uncertainty and inherent intermittence of renewable power generation units impose severe stresses on power systems. Energy storage systems such as battery energy storage system enables the power grid to improve acceptability of intermittent renewable energy generation. To do so, a successful coordination between renewable power generation units, ESSs and the grid is required. Nonetheless, with the existing grid architecture, achieving the aforementioned targets is intangible. In this regard, coupling renewable energy systems with different generation characteristics and equipping the power systems with the battery storage systems require a smooth transition from the conventional power system to the smart grid. Indeed, this coordination requires not only robust but also innovative controls and models to promote the implementation of the next-generation grid architecture. In this context, the present research proposes a smart grid architecture depicting a smart grid consisting of the main grid and multiple embedded micro-grids. Moreover, a focus has been given to micro-grid systems by proposing a “Micro-grid Key Elements Model” (MKEM). The proposed model and architecture are tested and validated by virtualization. The implementation of the virtualized system integrates solar power generation units, battery energy storage systems with the proposed grid architecture. The virtualization of the proposed grid architecture addresses issues related to Photovoltaic (PV) penetration, back-feeding, and irregularity of supply. The simulation results show the effect of Renewable Energy (RE) integration into the grid and highlight the role of batteries that maintain the stability of the system.

A Study on the Improvement of Smart Grid Security Performance and Blockchain Smart Grid Perspective

Interest in green energy has increased worldwide. Therefore, smart grid projects to form a more efficient and eco-friendly intelligent grid by combining information technology (IT) technology with the existing grid are actively being conducted. In Korea, a national-level smart grid project road map has been confirmed, and an action plan has been prepared. Despite such actions, there may appear various threat scenarios in the application of the IT to the grid as a reverse function. Security technology is a measure to respond to such threats effectively. The security technology of a smart grid is an important factor that is directly related to the success or failure of the smart grid project. A smart grid is a new type of next-generation grid born of the fusion with IT. If the smart grid, the backbone of the power supply, is damaged by a cyberattack, it may cause huge damage, such as a nationwide power outage. In fact, there is an increasing cyberattack threat, and the cyber security threat to the smart grid is not insignificant. Furthermore, the legal system related to information protection is also important in order to support it systematically. In this paper, the necessity of the smart grid is examined, and the industry’s initiative toward the smart grid security threat and threat response is examined. In this paper, we also suggest a security plan of applying Rainbowchain, the Blockchain technology, to the smart grid and energy exchange. We propose achieving superior performance and security functions by using Rainbowchain, which contains seven authentication techniques among existing Blockchain technologies, and propose the ecosystem and architecture necessary for its application.

Event- and Priority-Driven Coordination in Next-Generation Grid

The confluence of power and cyber networks is key to the evolution of smart grid (SG). The explosive growth of data in SG to support pervasive communication demands the exchange of essential information guided by need based events. The scaling of such asynchronous event-driven communication for practical utility in SG needs to evolve with information prioritization. Owing to the size of the power grid, it is often necessary to aggregate such event-driven data to reduce the multitasking overhead of higher-level controllers. As such, prioritization of the processing of these event-driven pieces of information is essential. In this paper, using the context of a neighborhood-area network, where communication is enabled between consumer loads and supervisor energy-management system (EMS) controller to achieve balance between demand and supply, a priority-based event-driven communication mechanism is outlined. For that purpose, load-demands are grouped into different classes based on their priorities. The demand processing policy based on dynamic-priorities is analyzed using delay and fairness performance parameters. An optimization problem is also formulated to achieve performance tradeoff between delays experienced by different classes of load-demands and the EMS processing cost. The performance evaluation results show the effectiveness of the proposed priority-based solution.

A Novel Ambipolar Nonaqueous All-Organic Redox Flow Battery and Its State of Charge Detection By FTIR

Nonaqueous redox flow batteries (NARFB) are considered as a promising next-generation grid scale energy storage solution because of their potential higher energy densities derived from the wide voltage window of nonaqueous electrolytes. Current research of NARFB is focused on redox materials development for various flow battery chemistries. Flow battery operation involves complexity associated with solvent-salt-redox species interactions, porous electrode, flow field, material crossover, etc., making it challenging to diagnose the real-time battery status. However, there is critical knowledge and technical gaps in this aspect. Especially, fast, robust and cost-effective diagnostic techniques are lacking to monitor state of charge (SOC) in a real-time manner to maintain safe and reliable long-term flow battery operations. In this research, we report a novel all-organic redox flow battery based on an ambipolar redox material and demonstrate Fourier Transform infrared spectroscopy (FTIR) as an effective method of detecting the SOC of this flow battery. The concentrations of the redox materials were derived from FTIR signal intensity by using the Beer-Lampert Law, which were used to calculate the SOC of the flow battery during the charge/discharge processes. The FTIR-based SOC determination agrees well with the electron spin resonance (ESR)-based measurements, demonstrating the feasibility of FTIR for online monitoring of the flow battery operation status. Also, the evolution of the FTIR spectra over repeated flow battery cycling offers a possible way to study the redox materials degradation and battery performance fading mechanism. This state of health (SOH) study can provide a direct prediction of cycle life of a NARFB. Figure 1

Microstructure and Sn Crystal Orientation Evolution in Sn-3.5Ag Lead-Free Solders in High-Temperature Packaging Applications

Understanding the reliability of eutectic Sn-3.5Ag lead-free solders in high-temperature packaging applications is of significant interest in power electronics for the next-generation electric grid. Large-area (2.5 mm × 2.5 mm) Sn-3.5Ag solder joints between silicon dies and direct bonded copper substrates were thermally cycled between 5°C and 200°C. Sn crystal orientation and microstructure evolution during thermal cycling were characterized by electron backscatter diffraction in the scanning electron microscope. Comparisons were made between the observed initial texture and microstructure and its evolution during thermal cycling. Gradual lattice rotation and grain boundary misorientation evolution observed due to thermal cycling suggested a continuous recrystallization mechanism. Recrystallization behavior was correlated with dislocation slip activities.

A user-mode distributed energy management architecture for smart grid applications

Future smart grids will require a flexible, observable, and controllable network architecture for reliable and efficient energy delivery under uncertain conditions. They will also necessitate variability in distributed energy generators and demand-side loads. This study presents a tree-like user-mode network architecture responding to these requirements. The approaches presented for the next-generation grid architecture facilitate the management of distributed generation strategies based on renewable sources, distributed storage, and demand-side load management.The authors draw a framework for the future digital power grid concept and assess its viability in relation to volatile, diverse generation and consumption possibilities. In this sense, probabilistic energy balance analyses of tree-like user-mode networks with a stochastic end-user population are conducted to investigate the energy reliability of the proposed grid. A case study based on published generation and consumption profile data is also presented, and several generation scenarios formed by variants of this data are discussed.

How internet concepts and technologies can help green and smarten the electrical grid

Several powerful forces are gathering to make fundamental and irrevocable changes to the century-old grid. The next-generation grid, often called the 'smart grid,' will feature distributed energy production, vastly more storage, tens of millions of stochastic renewable-energy sources, and the use of communication technologies both to allow precise matching of supply to demand and to incentivize appropriate consumer behaviour. These changes will have the effect of reducing energy waste and reducing the carbon footprint of the grid, making it 'smarter' and 'greener.' In this position paper, we discuss how the concepts and techniques pioneered by the Internet, the fruit of four decades of research in this area, are directly applicable to the design of a smart, green grid. This is because both the Internet and the electrical grid are designed to meet fundamental needs, for information and for energy, respectively, by connecting geographically dispersed suppliers with geographically dispersed consumers. Keeping this and other similarities (and fundamental differences, as well) in mind, we propose several specific areas where Internet concepts and technologies can contribute to the development of a smart, green grid. We also describe some areas where the Internet operations can be improved based on the experience gained in the electrical grid. We hope that our work will initiate a dialogue between the Internet and the smart grid communities.

The next-generation grid [Guest Editorial

The theme of this issue is "the next-generation grid," the same as PSCE 2009. We will discuss the electrical infrastructure of the future and what we will need to do to support a strong and growing economy in a sustainable and environmentally sensitive manner.

Special Issue: First International Workshop on Emerging Technologies for Next‐generation GRID (ETNGRID 2004)

Concurrency and Computation: Practice and ExperienceVolume 18, Issue 8 p. 803-805 EditorialFree Access Special Issue: First International Workshop on Emerging Technologies for Next-generation GRID (ETNGRID 2004) Angelo Corsaro, Angelo Corsaro SELEX SI—Strategic and Technological Planning, Roma, ItalySearch for more papers by this authorCorrado Santoro, Corrado Santoro Dipartimento di Ingegneria Informatica e delle Telecomunicazioni, Università di Catania, ItalySearch for more papers by this author Angelo Corsaro, Angelo Corsaro SELEX SI—Strategic and Technological Planning, Roma, ItalySearch for more papers by this authorCorrado Santoro, Corrado Santoro Dipartimento di Ingegneria Informatica e delle Telecomunicazioni, Università di Catania, ItalySearch for more papers by this author First published: 25 April 2006 https://doi.org/10.1002/cpe.975AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue8Special Issue: First International Workshop on Emerging Technologies for Next-generation GRID (ETNGRID 2004)July 2006Pages 803-805 RelatedInformation

Next Generation GRIDs for environmental science

GRIDs technology has developed from first generation, supplier-specific and configuration-specific systems through second generation systems providing metacomputing facilities over various underlying platforms. The 2.5 generation added facilities for fast data transfer (GRIDFTP) and directories (LDAP). The third generation embraced from the W3C (World Wide Web Consortium) community the idea of services, leading to OGSA (Open Grid Services Architecture). Under GGF (Global Grid Forum) auspices, a team from UK has developed OGSA/DAI (data access interface) which starts to make 3G GRIDs usable. However, others consider the existing architecture unsuitable for widespread acceptance beyond the metacomputing/supercomputing community. A small group of ERCIM experts was invited to give keynote presentations at an EC-sponsored workshop in January 2003 which had well over 200 participants. This led to a call from the community for documentation of NGG (Next Generation GRIDs). The three experts with the EC pulled together a team of 14 (including three more from ERCIM) which produced the ‘NGG Report’ in June 2003; the report is provided as an adjunct document to FP6 Calls for proposals. The key point is that the proposed NGG architecture is more suitable for environmental applications than the conventional 3G GRID. The characteristics and implications are discussed.

Grid computing - Securing next-generation grids

Grid computing poses tough security challenges. What do we have - and what do we still need - to make grids safe for tomorrow? Grid computing harnesses existing self contained systems - from personal computers to supercomputers to let users share processing cycles and data across geographical and organizational boundaries. This emerging technology can transform the computational infrastructure into an integrated, pervasive virtual environment. However, although commercial and research organizations might have collaborative or monetary reasons to share resources, they are unlikely to adopt such a distributed infrastructure until they can rely on the confidentiality of the communication, the integrity of their data and resources, and the privacy of the user information. In other words, large-scale deployment of grids will occur when users can count on their security.