Interconnection Scenarios Research Articles

A Novel Island Detection Threshold Setting Using Phasor Measurement Unit Voltage Angle in a Distribution Network

Islanding detection needs are becoming a pivotal constituent of the power system, since the penetration of distributed generators in the utility power system is continually increasing. Accurate threshold setting is an integral part of the island detection scheme since an inappropriate threshold might cause a hazardous situation. This study looked at the islanding conditions as well as two transient faults, such as a single line to ground fault and a three-phase balance fault, to assess the event distinguishing ability of the proposed method. Therefore, the goal of this research was to determine the threshold of the island if the distributed generator (DG) capacity is greater than the connected feeder load, which is the over-frequency island condition, and if the DG capacity is less than the connected feeder load, which is the under-frequency island condition. The significance of this research work is to propose a new island detection threshold setting method using the slip angle and acceleration angle that comes from phasor measurement unit (PMU) voltage angle data. The proposed threshold setting method was simulated in the PowerWorld simulator on a modified IEEE 30 bus system equipped with DG. There are three different interconnection scenarios in the test system and the performance of the proposed method shows that getting the island threshold for all the scenarios requires a single time step or 20 mile seconds after incepting an island into the network. In addition, it can distinguish between the real islanding threshold and the transient faults threshold.

Room-temperature self-healing piezoresistive sensors

Skin-inspired materials facilitate the design and fabrication of various biomedical devices capable of real-time monitoring of physiological signals and provide the foundations for mechanically compliant next-generation wearables that behave and operate like an extension of our own integumentary system. These devices need to maintain conformal contact with the body while offering very little mechanical impedance and must be able to sustain the accidental damage that comes in normal, dynamic, everyday life. This work demonstrates how dynamic metal-ligand self-healing chemistry can be used to synthesize multi-wall carbon nanotubes (MWCNT) – silicone nanocomposites with skin-like mechanical elasticity. Highly repeatable, room-temperature self-healing nanocomposites were synthesized with various filler concentrations to study the ability of the material to perform in sensing and electronic interconnect scenarios. An increase in mechanical stiffness from 8 kPa to 102 kPa were achieved at a percolation of 4.8 %wt, maintaining extensibility up to 50%. Further, conductivities as high as 2 × 10−2 S/m were achieved whilst maintaining high flexibility, offering tuneability for a broad range of tailored applications. The gauge factor (GF) performance was independent of healing cycles, maintaining a value of 1.4 after several ruptures, and continually sustains mechanical stiffness matching the dermal layer of the human forearm. These results parallel the human skin's ability to both heal damage elements and respond to stimuli of the world around us and provide expandability to current biomedical systems.

IM/DD mode division multiplexing transmission enabled by machine learning-based linear and nonlinear MIMO equalization

We demonstrate two mode division multiplexing transmission systems through few-mode fiber by using two degenerate LP11 modes in high speed and low cost optical interconnection scenarios. Two novel MIMO equalizers based on machine learning are proposed and utilized to eliminate the impairments. In the ultra-low cost optical interconnection, the linear equalizer based on the elastic net can effectively reduce the bit error rate to the hard-decision forward error correction threshold with an extremely fast convergence speed. With the help of the nonlinear equalizer based on the neural network, high speed short-reach transmission has been achieved. By multiplexing two degenerate modes with the bit rate of 100 Gb/s/λ, 2 × 100 Gb/s transmission of 30 G-class 1550 nm optical devices has been realized. Without the optical amplifier, the receiver sensitivity could be around -11 dBm in 2 × 50 Gb/s transmission. This provides potential solutions for the future evolution of short-reach optical links.

Future Directions for Power System Interconnection from Korea’s Perspective

The power system interconnection between Northeast Asian countries has been discussed since 2000 but has not been realized to date due to various obstacles. This paper specifies the expected future energy policy, long-term energy supply plan, and necessity of power interconnection from the Korean viewpoint, including the climate change agreement. There are very many interconnection scenarios presented by various institutes in NEA countries now. These studies contain the overall preliminary feasibility results but do not consider the environmental effects, energy security, and market reforms. Do these existing studies show how we could interconnect specific countries? This paper discusses the trading potentials for green energy utilization between countries and some obstacles to be removed to promote the energy interconnection projects from technical, economic, marketable, and energy security standpoints. Especially, energy security in terms of politics, as well as vulnerability characteristics of renewable energy, could cause the interconnected system blackouts. These could be a serious obstacle to realization and continuous stable operation of these interconnection projects. Finally, this paper will specify the future directions and possible scenarios for power system interconnection by integrating these issues comprehensively from Korea's perspective.

Towards Flexible Integration of 5G and IIoT Technologies in Industry 4.0: A Practical Use Case

The Industry 4.0 revolution envisions fully interconnected scenarios in the manufacturing industry to improve the efficiency, quality, and performance of the manufacturing processes. In parallel, the consolidation of 5G technology is providing substantial advances in the world of communication and information technologies. Furthermore, 5G also presents itself as a key enabler to fulfill Industry 4.0 requirements. In this article, the authors first propose a 5G-enabled architecture for Industry 4.0. Smart Networks for Industry (SN4I) is introduced, an experimental facility based on two 5G key-enabling technologies—Network Functions Virtualization (NFV) and Software-Defined Networking (SDN)—which connects the University of the Basque Country’s Aeronautics Advanced Manufacturing Center and Faculty of Engineering in Bilbao. Then, the authors present the deployment of a Wireless Sensor Network (WSN) with strong access control mechanisms into such architecture, enabling secure and flexible Industrial Internet of Things (IIoT) applications. Additionally, the authors demonstrate the implementation of a use case consisting in the monitoring of a broaching process that makes use of machine tools located in the manufacturing center, and of services from the proposed architecture. The authors finally highlight the benefits achieved regarding flexibility, efficiency, and security within the presented scenario and to the manufacturing industry overall.

Exploring the driving factors and their mitigation potential in global energy-related CO2 emission

In order to quantify the contribution of the mitigation strategies, an extended Kaya identity has been proposed in this paper for decomposing the various factors that influence the CO2 emission. To this end, we provided a detailed decomposition of the carbon intensity and energy intensity, which enables the quantification of clean energy development and electrification. The logarithmic mean divisia index (LMDI) has been applied to the historical data to quantify the contributions of the various factors affecting the CO2 emissions. Further, the global energy interconnection (GEI) scenario has been introduced for providing a systematic solution to meet the 2°C goal of the Paris Agreement. By combining LMDI with the scenario analysis, the mitigation potential of the various factors for CO2 emission has been analyzed. Results from the historical data indicate that economic development and population growth contribute the most to the increase in CO2 emissions, whereas improvement in the power generation efficiency predominantly helps in emission reduction. A numerical analysis, performed for obtaining the projected future carbon emissions, suggests that clean energy development and electrification are the top two factors that can decrease CO2 emissions, thus showing their great potential for mitigation in the future. Moreover, the carbon capture and storage technology serves as an important supplementary mitigation method.

Escenarios prospectivos de un nuevo orden internacional que se vislumbra luego de la pandemia COVID-19

Hay buenas razones para suponer que los estragos ocasionados por la pandemia de la COVID-19 en la primera mitad del 2020, erosionan de tal manera los cimientos del orden mundial imperante, estructurado desde las postrimerías de la segunda guerra mundial, que desde ya se articulan las condiciones de posibilidad para la emergencia de un nuevo o renovado orden internacional con características inciertas. En consecuencia, el objetivo de esta investigación es debatir las implicaciones políticas, económicas y socioculturales de la hipótesis del nuevo orden mundial post-coronavirus y, simultáneamente, configurar algunos escenarios posibles que bien podrían determinar el futuro próximo de las civilizaciones humanas según la lectura de Harari (2014; 2015; 2018). En lo metodológico, se empleó la hermenéutica de la comprensión dialógica de Gadamer, como herramienta ventajosa cuando se trata de visualizar escenarios internacionales, junto al análisis prospectivo como pretexto para relacionar el acontecer mundial, con los textos y contextos que le dan sentido. Entre las conclusiones destaca que la crisis del orden mundial vigente es resultado de un proceso de declive histórico de los grandes modelos políticos y económicos dominantes hasta el presente y que el futuro próximo puede interpretarse mediante la visualización de tres escenarios posibles e interconectados.

Adaptive Coherent Receiver Settings for Optimum Channel Spacing in Gridless Optical Networks

In this paper, we propose a novel circuit and system to optimize the spacing between optical channels in gridless (also called flexible-grid or elastic) networking. The method will exploit the beginning-of-life link margin by enabling the channel to operate in super-Nyquist dense wavelength division multiplexing mode. We present the work in the context of software-defined networking and high-speed optical flexible-rate transponders. The clock recovery scheme allows the mitigation of jitter by decoupling the contribution of high-jitter noise sources from the clock recovery loop. The method and associated algorithm are experimentally verified where a spectrum gain of up to 2 GHz in spacing between two channels in the Media Channel (MC) is obtained compared to conventional clocking strategies. We showed that the improvement is equivalent to increasing throughput, in a data-center interconnect scenario, by up to 300 giga-bits per second per route.

Analysis of Water Resource Benefits Due to Power Grid Interconnections Using the Virtual Water Method

The global water demand and supply situation is becoming increasingly severe due to water shortage and uneven distribution of water resources. The highest water demand in the energy sector is attributable to power generation. With cross-country and cross-continental power grid interconnections becoming a reality, electricity trading across countries and the creation of new opportunities for re-allocation of water resources are possible. This study expands the concept of virtual water and proposes a generalized virtual water flow in an interconnected power grid system to accurately estimate water resource benefits of clean power transmission from both the production and the consumption sides. By defining the water scarcity index as a price mechanism indicator, the benefits of water resources allocation through power grid interconnections are evaluated. Taking the Africa-Asia-Europe interconnection scenario as an example, the total water saving would amount to 88.95 million m3 by 2030 and 337.8 million m3 by 2050. This result shows that grid interconnections could promote the development of renewable energy and expand the benefits of available water resources.

5G Message Service System Based on Artificial Immune Dynamic Adaptive Mechanism

When facing massive interconnection scenarios of terminals, 5G message service system needs to support large-scale information access and management and provides the efficient and reliable signal control to scheduling a variety of wireless access networks. In this paper, artificial immune theory is applied to the 5G message services. The simulating the immune response mechanism, a semi-distributed dynamic adaptive immune network architecture was proposed. The dynamic learning mechanism and immune memory mechanism of the detector were established, which improved the 5G edge computing capability and reduced the load of the 5G core network. The concept of the immune message distribution system (IMDS) is proposed, which uses clonal selection algorithm to classify and clone the message header, and combines with the affirmative selection algorithm to carry out high-frequency variation on the message body. On the premise of ensuring the diversity of antibodies, the space consumption problem of the hash-map algorithm is effectively solved, and the efficiency of message distribution is improved. The comparison of simulation results shows that the IMDS improves the message recognition ability and adaptive ability of the 5G system and proves the feasibility of semi-distributed immune dynamic learning mechanism.

TOWARDS A 5G COMPLIANT AND FLEXIBLE CONNECTED MANUFACTURING FACILITY

The incoming smart Industry 4.0 envisions fully interconnected scenarios to boost the efficiency, quality and performance of industrial processes. In this context, communication technologies play a pivotal role as the key tool that enables the interconnection among a priori isolated business processes, making the most of them and resulting in more powerful business-level applications and decision-making. In this paper, we present the application of two cutting-edge telecommunication technologies, namely, network function virtualization (NFV) and software-defined networking (SDN), to the manufacturing industry, showing how these technologies can help improve manufacturing processes. We introduce the SN4I (Smart Networks for Industry) experimental facility, which is an NFV- and SDN-aware communication network that connects the University of the Basque Country with the Aeronautics Advanced Manufacturing Centre. In this regard, NFV provides a flexible way to deploy virtual services, while SDN allows the programming of network elements to interconnect these virtual services by means of virtual links or virtual networks. Both technologies guarantee full data and performance level isolation, ensuring that virtual services running over the same physical hardware or virtual links deployed over the same physical network will never interfere with one another. With the integration of NFV and SDN in manufacturing networks, the design, evaluation and deployment time of services that include computational, storage and networking resources is drastically decreased, facilitating innovation and optimizing network and hardware resource utilization. Key Words: 5G, experimental facility, Industry 4.0, manufacturing network function virtualization (NFV), software-defined networking (SDN)

Environmental Benefit Assessment under the Vision of Global Energy Interconnection

Under the vision of Global Energy Interconnection (GEI), which can optimally allocate global resources and bring huge positive benefits to ecological environment, this paper proposes interconnection and disconnection power planning scenarios. By establishing a GEI environmental benefit assessment index system, benefits like resource saving, atmospheric pollutant emission reduction and combating to climate change benefits, can be evaluated quantitatively. The results indicated that, GEI could not only bring huge resource conservation benefits and conventional pollutant emission reduction benefits, but also ease global climate change by achieving the goal of 2 degree Centigrade global temperature rise control under the interconnection scenario.

Challenges for the Baltic Power System connecting synchronously to Continental European Network

The article proposes a multi-project Baltic States – Continental Europe Synchronous Interconnection Scenario for 2014–2027, with the insight to the former development of the Baltic Power System and a short listing of synchronous interconnection precedents in Europe. The study identifies and discusses the major operational challenges for the Baltic Power System in synchronously connecting the Continental European Network (CEN) via the recently commissioned Polish–Lithuanian tie LitPol Link1 and the projected LitPol Link2. The HVDC converter stations on asynchronous ties with Russia, Belarus and Nordic systems are recommended for the exchange of frequency containment and restoration reserves, notably in the DC-supported island operation condition of the Baltic Power System.

SUDOI: software defined networking for ubiquitous data center optical interconnection

Ubiquitous data center optical interconnection is a promising scenario to meet the high burstiness and high-bandwidth requirements of services in terms of the user-access-oriented interconnection between user and data center, inter-data- center, and intra-data-center interconnection. However, in the current mode of operation, the control of the data center and optical network is separately deployed. Enabling even limited interworking among these separated control systems does not provide a mechanism to exchange resource information and enhance the high-level performance requirement of applications. Our previous work implemented cross-stratum optimization of optical network and application strata resources inter-data-center, which allows the accommodation of data center services. In view of this, this study extends to the ubiquitous data center optical interconnection scenario. This article presents a novel SUDOI architecture aimed at extensive user access from the perspective of heterogeneous cross-stratum and multi-layer networking modes. SUDOI can enable cross-stratum optimization of application and optical network stratum resources, and enhance multiple- layer resource integration in the ubiquitous data center optical interconnection. The functional modules of SUDOI architecture, including the core elements of various controllers, are described in detail. The cooperation procedure in user-access-oriented interconnection, multiple- layer resource integration inter-data-center, and intra-data-center service modes is investigated. The feasibility and efficiency of the proposed architecture are also experimentally demonstrated on our OaaS testbed with OpenFlow-enabled optical nodes, and compared to the CSO scheme in terms of blocking probability and resource occupation rate. Numerical results are given and analyzed based on the testbed. Some future discussion and exploration issues are presented in the conclusion.

Towards a semantic-driven and scalable publish/subscribe framework

Heterogeneous networks, including personal, home and collaborative enterprise networks are aimed at interconnecting diverse communities of users. In the case of large communities of mobile, distributed and collaborating users sharing their multimedia content, scalable and semantic approaches are needed to facilitate the efficient publication and discovery of data. In this work, we propose an approach aimed at efficiently providing the required functionalities for dynamically managing the resources and the multimedia content of interconnected home networks, as well as providing the required community sharing capabilities. Our solution consists in combining the benefits of both ontologies and peer-to-peer approaches, by taking advantage of the semantic capabilities of ontologies at local domain level and the scalable P2P solutions at inter-domains level. Our proposed framework is founded on a new architecture based on peer-to-peer event-based communication system and using mainly a home box entity based on a global multimedia ontology. This domain ontology allows publishers and subscribers to use a common semantic space to characterise production and consumption of resources and services. Our approach can also be applied for similar large interconnected systems scenarios such as topic discovery with JNDI and service exchange with UDDI.

Performance and Power Dissipation Comparisons Between 28 Gb/s NRZ, PAM, CAP and Optical OFDM Systems for Data Communication Applications

Theoretical investigations have been carried out to analyze and compare the link power budget and power dissipation of non-return-to-zero (NRZ), pulse amplitude modulation-4 (PAM-4), carrierless amplitude and phase modulation-16 (CAP-16) and 16-quadrature amplitude modulation-orthogonal frequency division multiplexing (16-QAM-OFDM) systems for data center interconnect scenarios. It is shown that for multimode fiber (MMF) links, NRZ modulation schemes with electronic equalization offer the best link power budget margins with the least power dissipation for short transmission distances up to 200 m; while OOFDM is the only scheme which can support a distance of 300 m albeit with power dissipation as high as 4 times that of NRZ. For short single mode fiber (SMF) links, all the modulation schemes offer similar link power budget margins for fiber lengths up to 15 km, but NRZ and PAM-4 are preferable due to their system simplicity and low power consumption. For lengths of up to 30 km, CAP-16 and OOFDM are required although the schemes consume 2 and 4 times as much power respectively compared to that of NRZ. OOFDM alone allows link operation up to 35 km distances.

Multi-Optical Network-on-Chip for Large Scale MPSoC

Optical network-on-chip (ONoC) architectures are emerging as promising contenders to solve bandwidth and latency issues in multiprocessor systems-on-chip (MPSoC). However, current on-chip integration technologies for optical interconnect allow interconnecting only dozens of IPs. Scaling with MPSoCs composed of hundreds of IPs thus, relies on unpredictable technological innovations. In this letter, we propose a method that combines multiple ONoCs. Each ONoC is small enough to rely on already existing and proven technologies. We evaluate the approach for various interconnect scenarios, showing that it scales well with the size of the MPSoC architectures.

A Scalable Power-Line-Signaling-Based Scheme for Islanding Detection of Distributed Generators

Power-line-signaling-based schemes are regarded as promising solutions to the problem of islanding detection of distributed generators (DGs). These schemes broadcast dedicated signals from the distribution substation to the downstream DGs and, therefore, transform the detection of islanded DGs into the determination of the signal presence at the DG sites. This paper presents an improvement to a published power-line-signaling method. With this improvement, the signaling device can be located anywhere between the substation and the DG sites, creating the opportunity for designing customized islanding detection arrangements for various DG interconnection scenarios. Simulations and laboratory tests show that the improved scheme can work reliably.

Flexible-attribute problems

Problems with significant input-data uncertainty are very common in practical situations. One approach to dealing with this uncertainty is called scenario planning, where the data uncertainty is represented with scenarios. A scenario represents a potential realization of the important parameters of the problem. In this paper we present a new approach to coping with data uncertainty, called the flexibility approach. Here a problem is described as a set of interconnected simple scenarios. The idea is to find a solution for each scenario such that, after a change in scenario, transforming from one solution to the other one is not expensive. We define two versions of flexibility and hence two versions of the problem, which are called the sum-flexible-attribute problem and the max-flexible-attribute problem. For both problems we prove the $\ensuremath{\mathcal{NP}}$ -hardness as well as the non-approximability. We present polynomial time algorithms for solving the two problems to optimality on trees. Finally, we discuss the possible applications and generalizations of the new approach.

Concept for Mobility and Interconnections Aspects in Converged NGN-Based IPTV Architecture

The progress and evolution trends in the area of ICT and ICT infrastructure based on convergence processes create new opportunities. Service providers and network operators can provide a wide spectrum of multimedia services and applications to end users. The IPTV services represent a specific group of multimedia services which are in the sphere of interest of the telecommunication technical community but also subscribers. Standardization bodies like ETSI TISPAN or ITU-T have defined standards for NGN-based IPTV architecture and services (IMS and non-IMS). The paper evaluates possibilities and potential architecture for concept of converged NGN IPTV. New vision of the converged NGN IPTV architecture is presented together with proposed enhancements compared to IMS-based IPTV where single converged platform can serve fixed, mobile, or wireless terminals. The concept for IPTV service roaming with mobility support and different interconnection scenarios are discussed with intention to show potential user benefits.