Silicon-based optoelectronic heterogeneous integration for optical interconnection

The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated packaging.This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection.The research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.

Research on Scheduling Strategy of Flexible Interconnection Distribution Network Considering Distributed Photovoltaic and Hydrogen Energy Storage

Distributed photovoltaic(PV)is one of the important power sources for building a new power system with new energy as the main body.The rapid development of distributed PV has brought new challenges to the operation of distribution networks.In order to improve the absorption ability of large-scale distributed PV access to the distribution network,the AC/DC hybrid distribution network is constructed based on flexible interconnection technology,and a coordinated scheduling strategy model of hydrogen energy storage(HS)and distributed PV is established.Firstly,the mathematical model of distributed PV and HS system is established,and a comprehensive energy storage system combining seasonal hydrogen energy storage(SHS)and battery(BT)is proposed.Then,a flexible interconnected distribution network scheduling optimization model is established to minimize the total active power loss,voltage deviation and system operating cost.Finally,simulation analysis is carried out on the improved IEEE33 node,the NSGA-II algorithm is used to solve specific examples,and the optimal scheduling results of the comprehensive economy and power quality of the distribution network are obtained.Compared with the method that does not consider HS and flexible interconnection technology,the network loss and voltage deviation of this method are lower,and the total system cost can be reduced by 3.55%,which verifies the effectiveness of the proposed method.

Coordinated planning for flexible interconnection and energy storage system in low-voltage distribution networks to improve the accommodation capacity of photovoltaic

The increasing proportion of distributed photovoltaics(DPVs)and electric vehicle charging stations in low-voltage distribution networks(LVDNs)has resulted in challenges such as distribution transformer overloads and voltage violations.To address these problems,we propose a coordinated planning method for flexible interconnections and energy storage systems(ESSs)to improve the accommodation capacity of DPVs.First,the power-transfer characteristics of flexible interconnection and ESSs are analyzed.The equipment costs of the voltage source converters(VSCs)and ESSs are also analyzed comprehensively,considering the differences in installation and maintenance costs for different installation locations.Second,a bilevel programming model is established to minimize the annual comprehensive cost and yearly total PV curtailment capacity.Within this framework,the upper-level model optimizes the installation locations and capacities of the VSCs and ESSs,whereas the lower-level model optimizes the operating power of the VSCs and ESSs.The proposed model is solved using a non-dominated sorting genetic algorithm with an elite strategy(NSGA-II).The effectiveness of the proposed planning method is validated through an actual LVDN scenario,which demonstrates its advantages in enhancing PV accommodation capacity.In addition,the economic benefits of various planning schemes with different flexible interconnection topologies and different PV grid-connected forms are quantitatively analyzed,demonstrating the adaptability of the proposed coordinated planning method.

Review of trans-Mediterranean power grid interconnection:a regional roadmap towards energy sector decarbonization

Climate change is becoming an important issue in all fields of infrastructure development.Electricity plays a core role in the decarbonized energy system’s path to a regional zero-emission pattern.A well-built trans-Mediterranean backbone grid can hedge the profound evolution of regional power generation,transmission,and consumption.To date,only Turkey and the Maghreb countries(i.e.,Morocco,Algeria,and Tunisia)are connected with the Continental European Synchronous Area.Other south-and east-shore countries have insufficient interconnection infrastructures and synchronization difficulties that have proven to be major hurdles to the implementation of large-scale solar and wind projects and achievement of climate goals.This study analyzes the current trans-boundary grid interconnections and power and carbon emission portfolios in the Mediterranean region.To align with the recently launched new climate target‘Fit for 55’program and the accelerated large-scale renewables target,a holistic review of projected trans-Mediterranean grids and their market,technical,and financial obstacles of implementation was conducted.For south-and east-shore countries,major legal and regulatory barriers encompassing non-liberalized market structure,regulation gaps of taxation and transmission tariffs,and the private sector’s access rights need to be removed.Enhancement of domestic grids,substations,and harmonized grid codes and frequency,voltage,and communication technology standards among all trans-Mediterranean countries are physical prerequisites for implementing the Trans-Mediterranean Electricity Market.In addition,the mobilization of capital instruments along with private and international investments is indispensable for the realization of supranational transmission projects.As the final section of the decarbonization roadmap,the development of electric appliances,equipment,and vehicles with higher efficiency is inevitable in the decarbonized building,transportation,and industry sectors.

Power Optimization Cooperative Control Strategy for Flexible Fast Interconnection Device with Energy Storage

With the wide application of renewable energy power generation technology,the distribution network presents the characteristics of multi-source and complex structure.There are potential risks in the stability of power system,and the problem of power quality is becoming more and more serious.This paper studies and proposes a power optimization cooperative control strategy for flexible fast interconnection device with energy storage,which combines the flexible interconnection technology with the energy storage device.The primary technology is to regulate the active and reactive power of the converter.By comparing the actual power value of the converter with the reference value,the proportional integral(PI)controller is used for correction,and the current components of d and q axes are obtained and input to the converter as the reference value of the current inner loop.The control strategy in this paper can realize power mutual aid between feeders,and at the same time,the energy storage device can provide or absorb a certain amount of power for feeders,so that the power grid can realize stable operation in a certain range.

A Scalable Interconnection Scheme in Many-Core Systems

Recent architectures of multi-core systems may have a relatively large number of cores that typically ranges from tens to hundreds;therefore called many-core systems.Such systems require an efficient interconnection network that tries to address two major problems.First,the overhead of power and area cost and its effect on scalability.Second,high access latency is caused by multiple cores’simultaneous accesses of the same shared module.This paper presents an interconnection scheme called N-conjugate Shuffle Clusters(NCSC)based on multi-core multicluster architecture to reduce the overhead of the just mentioned problems.NCSC eliminated the need for router devices and their complexity and hence reduced the power and area costs.It also resigned and distributed the shared caches across the interconnection network to increase the ability for simultaneous access and hence reduce the access latency.For intra-cluster communication,Multi-port Content Addressable Memory(MPCAM)is used.The experimental results using four clusters and four cores each indicated that the average access latency for a write process is 1.14785±0.04532 ns which is nearly equal to the latency of a write operation in MPCAM.Moreover,it was demonstrated that the average read latency within a cluster is 1.26226±0.090591 ns and around 1.92738±0.139588 ns for read access between cores from different clusters.

Impact of interconnections and renewable energy integration on the Philippine-Sabah Power Grid systems

This study presents a comprehensive impact analysis of the rotor angle stability of a proposed international connection between the Philippines and Sabah,Malaysia,as part of the Association of Southeast Asian Nations(ASEAN)Power Grid.This study focuses on modeling and evaluating the dynamic performance of the interconnected system,considering the high penetration of renewable sources.Power flow,small signal stability,and transient stability analyses were conducted to assess the ability of the proposed linked power system models to withstand small and large disturbances,utilizing the Power Systems Analysis Toolbox(PSAT)software in MATLAB.All components used in the model are documented in the PSAT library.Currently,there is a lack of publicly available studies regarding the implementation of this specific system.Additionally,the study investigates the behavior of a system with a high penetration of renewable energy sources.Based on the findings,this study concludes that a system is generally stable when interconnection is realized,given its appropriate location and dynamic component parameters.Furthermore,the critical eigenvalues of the system also exhibited improvement as the renewable energy sources were augmented.

Reliability Assessment of a New General Matching Composed Network

The reliability of a network is an important indicator for maintaining communication and ensuring its stable operation. Therefore, the assessment of reliability in underlying interconnection networks has become an increasingly important research issue. However, at present, the reliability assessment of many interconnected networks is not yet accurate,which inevitably weakens their fault tolerance and diagnostic capabilities. To improve network reliability,researchers have proposed various methods and strategies for precise assessment. This paper introduces a novel family of interconnection networks called general matching composed networks(gMCNs), which is based on the common characteristics of network topology structure. After analyzing the topological properties of gMCNs, we establish a relationship between super connectivity and conditional diagnosability of gMCNs. Furthermore, we assess the reliability of g MCNs, and determine the conditional diagnosability of many interconnection networks.

Distribution Line Longitudinal ProtectionMethod Based on Virtual Measurement Current Restraint

As an effective approach to achieve the“dual-carbon”goal,the grid-connected capacity of renewable energy increases constantly.Photovoltaics are the most widely used renewable energy sources and have been applied on various occasions.However,the inherent randomness,intermittency,and weak support of grid-connected equipment not only cause changes in the original flow characteristics of the grid but also result in complex fault characteristics.Traditional overcurrent and differential protection methods cannot respond accurately due to the effects of unknown renewable energy sources.Therefore,a longitudinal protection method based on virtual measurement of current restraint is proposed in this paper.The positive sequence current data and the network parameters are used to calculate the virtual measurement current which compensates for the output current of photovoltaic(PV).The waveform difference between the virtual measured current and the terminal current for internal and external faults is used to construct the protection method.An improved edit distance algorithm is proposed to measure the similarity between virtual measurement current and terminal measurement current.Finally,the feasibility of the protection method is verified through PSCAD simulation.

Reliability Analysis of Varietal Hypercube

Connectivity is a vital metric to explore fault tolerance and reliability of network structure based on a graph model. Let be a connected graph. A connected graph G is called supper-κ (resp. supper-λ) if every minimum vertex cut (edge cut) of G is the set of neighbors of some vertex in G. The g-component connectivity of a graph G, denoted by , is the minimum number of vertices whose removal from G results in a disconnected graph with at least g components or a graph with fewer than g vertices. The g-component edge connectivity can be defined similarly. In this paper, we determine the g-component (edge) connectivity of varietal hypercube for small g.

Unraveling the efficiency losses and improving methods in quantum dot-based infrared up-conversion photodetectors

Quantum dot-based up-conversion photodetector,in which an infrared photodiode(PD)and a quantum dot light-emitting diode(QLED)are back-to-back connected,is a promising candidate for low-cost infrared imaging.However,the huge efficiency losses caused by integrating the PD and QLED together hasn’t been studied sufficiently.This work revealed at least three origins for the efficiency losses.First,the PD unit and QLED unit usually didn’t work under optimal conditions at the same time.Second,the potential barriers and traps at the interconnection between PD and QLED units induced unfavorable carrier recombination.Third,much emitted visible light was lost due to the strong visible absorption in the PD unit.Based on the understandings on the loss mechanisms,the infrared up-conversion photodetectors were optimized and achieved a breakthrough photon-to-photon conversion efficiency of 6.9%.This study provided valuable guidance on how to optimize the way of integration for up-conversion photodetectors.

Carbon neutrality policy and interconnection scenario according to the perspective of Republic of Korea

The future energy policy,long-term energy supply plan,and necessity of power system interconnection are discussed considering the climate change agreement and national carbon neutrality policy.Although several studies have been conducted on power system interconnection related projects,a few reviews have been performed related to the Greenhouse Gas Convention in North-East Asian(NEA)regions.Therefore,the future directions and possible scenarios on power system interconnection are studied by combining the issues by comprehensively considering carbon neutrality policy according to the perspective of Korea.

Consensus of Second-order Multi-agent Systems with Nonsymmetric Interconnection and Heterogeneous Delays

In this paper, a consensus algorithm of multi-agent second-order dynamical systems with nonsymmetric interconnection and heterogeneous delays is studied. With the hypothesis of directed weighted topology graph with a globally reachable node, decentralized consensus condition is obtained by applying generalized Nyquist criterion. For the systems with both communication and input delays, it is shown that the consensus condition is dependent on input delays but independent of communication delays.

Application research on large-scale battery energy storage system under Global Energy Interconnection framework

In the context of constructing Global Energy Interconnection(GEI), energy storage technology, as one of the important basic supporting technologies in power system, will play an important role in the energy configuration and optimization. Based on the most promising battery energy storage technology, this paper introduces the current status of the grid technology, the application of large-scale energy storage technology and the supporting role of battery energy storage for GEI. Based on several key technologies of large-scale battery energy storage system, preliminary analysis of the standard system construction of energy storage system is made, and the future prospect is put forward.

Review on failure analysis of interconnections in power devices

Interconnections in microelectronic packaging are not only the physical carrier to realize the function of electronic circuits,but also the weak spots in reliability tests.Most of failures in power devices are caused by the malfunction of interconnections,including failure of bonding wire as well as cracks of solder layer.In fact,the interconnection failure of power devices is the result of a combination of factors such as electricity,temperature,and force.It is significant to investigate the failure mechanisms of various factors for the failure analysis of interconnections in power devices.This paper reviews the main failure modes of bonding wire and solder layer in the interconnection structure of power devices,and its failure mechanism.Then the reliability test method and failure analysis techniques of interconnection in power device are introduced.These methods are of great significance to the reliability analysis and life prediction of power devices.

Long-term cross-border electricity trading model under the background of Global Energy Interconnection

Environmental problems caused by traditional power production and the unbalanced distribution of energy resources and demand limit the development of sustainable societies. A feasible method to optimize the resource allocation has been proposed, and it involves cross-border and cross-regional electricity transactions. However, the uncertainty of renewable energy and the specific features of the cross-border electricity market are key issues which need to be considered in the trading mechanism design. Based on this, this paper sets up a long-term cross-border electricity trading model considering the uncertainty of renewable energy. First, annual transactions are matched according to the declared data of bidders with consideration of cross-border interconnection development benefits, potential benefit risks, and transmission costs. Second, for annual contract decomposition, the model uses the minimum generation cost function with a penalty item for power shortages to allocate electricity to each month. Additionally, the scenario reduction algorithm is combined with the unit commitment to construct a stochastic generation plan. Finally, a case study of the numerical results for the multinational electricity market in northeast Asia is used to show that the proposed trading model is feasible for cross-border electricity trading with high penetration of renewable energy.

Analysis of profit models for cross-border power interconnection projects

With the increasing demand worldwide for power grid interconnection,a growing number of related projects are under planning or construction.Despite the rapid growth of cross-border interconnection projects,the systematic research on profit models for these projects is insufficient.This paper first analyzes the profit sources of interconnection projects.Based on the analysis results,profit models are considered under different regulatory systems for three types of crossborder interconnection projects:fully market-oriented,semi-marketization,and fully supervised.Finally,measures for increasing the profitability and sustainable development of power interconnection projects are proposed.

Research on reliability index of a large communication network with domain partition and interconnection

In order to indicate the performances of a large-scale communication network with domain partition and interconnection today, a kind of reliability index weighed by normalized capacity is defined. Based on the route rules of network with domain partition and interconnection, the interconnection indexes among the nodes within the domain and among the domains are given from several aspects. It is expatiated on that the index can thoroughly represent the effect on the reliability index of the objective factor and the subjective measures of the designer, which obeys the route rules of a network with domain partition and interconnection. It is discussed that the defined index is rational and compatible with the traditional index.

Joint electricity and carbon market for Northeast Asia energy interconnection

Decarbonization of the electricity sector is crucial to mitigate the impacts of climate change and global warming over the coming decades.The key challenges for achieving this goal are carbon emission trading and electricity sector regulation,which are also the major components of the carbon and electricity markets,respectively.In this paper,a joint electricity and carbon market model is proposed to investigate the relationships between electricity price,carbon price,and electricity generation capacity,thereby identifying pathways toward a renewable energy transition under the transactional energy interconnection framework.The proposed model is a dynamically iterative optimization model consisting of upper-level and lower-level models.The upper-level model optimizes power generation and obtains the electricity price,which drives the lower-level model to update the carbon price and electricity generation capacity.The proposed model is verified using the Northeast Asia power grid.The results show that increasing carbon price will result in increased electricity price,along with further increases in renewable energy generation capacity in the following period.This increase in renewable energy generation will reduce reliance on carbon-emitting energy sources,and hence the carbon price will decline.Moreover,the interconnection among zones in the Northeast Asia power grid will enable reasonable allocation of zonal power generation.Carbon capture and storage (CCS) will be an effective technology to reduce the carbon emissions and further realize the emission reduction targets in 2030-2050.It eases the stress of realizing the energy transition because of the less urgency to install additional renewable energy capacity.

Research on big data applications in Global Energy Interconnection

Construction of Global Energy Interconnection(GEI) is regarded as an effective way to utilize clean energy and it has been a hot research topic in recent years. As one of the enabling technologies for GEI, big data is accompanied with the sharing, fusion and comprehensive application of energy related data all over the world. The paper analyzes the technology innovation direction of GEI and the advantages of big data technologies in supporting GEI development, and then gives some typical application scenarios to illustrate the application value of big data. Finally, the architecture for applying random matrix theory in GEI is presented.