Efficient PbS quantum dots tandem solar cells through compatible interconnection layer

Lead sulfide quantum dots(PbS QDs) hold unique characteristics, including bandgap tunability, solutionprocessability etc., which make them highly applicable in tandem solar cells(TSCs). In all QD TSCs, its efficiency lags much behind to their single junction counterparts due to the deficient interconnection layer(ICL) and defective subcells. To improve TSCs performance, we developed three kinds of ICL structures based on 1.34 and 0.96 e V PbS QDs subcells. The control, 1,2-ethanedithiol capped PbS QDs(PbS-EDT)/Au/tin dioxide(SnO_(2))/zinc oxide(Zn O), utilized SnO_(2) layer to obtain high surface compactness.However, its energy level mismatch causes incomplete recombination. Bypassing it, the second ICL(PbS-EDT/Au/Zn O) removed SnO_(2) and boosted the power conversion efficiency(PCE) from 5.75% to 8.69%. In the third ICL(PbS-EDT/poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA)/Au/Zn O), a thin layer of PTAA can effectively fill fissures on the surface of PbS-EDT and also protect the front cells from solvent penetration. This TSC obtained a PCE of 9.49% with an open circuit voltage of 0.91 V, a short circuit current density of 15.47 m A/cm~2, and a fill factor of 67.7%. To the best of our knowledge, this was the highest PCE achieved by all PbS QD TSCs reported to date. These TSCs maintained stable performance for a long working time under ambient conditions.

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.

Utilization of cross-regional interconnector and pumped hydro energy storage for further introduction of solar PV in Japan

The amount of solar PV installed capacity has steadily increased to 44.5 GW at the end of FY2017,since the introduction of the Feed in Tariff(FiT)to Japan in 2012.On the other hand,since the first curtailment of solar PV was conducted on October 13th,2018 in the Kyushu area,the curtailment has been frequently executed including wind power after that.In this study,cross-regional interconnector and pumped hydro energy storage(PHES)are focused on mitigating curtailment.In Japan,there are 9 electric power areas which connected each other by cross-regional interconnectors.According to the historical operation,cross-regional interconnectors were secured as emergency flexible measures,but after the implicit auction was started from October 2018,it is used on merit order.Regarding a PHES in Japan,they have been built with nuclear power plants for several decades.Because the output of nuclear power generation is constant,so the PHES is used to absorb the surplus at nighttime when the demand declines.All nuclear power plants in Japan have been shut down after the accident at the Fukushima Daiichi Nuclear Power Plant following the Great East Japan Earthquake that occurred on March 11th,2011.There are several nuclear power plants that have been restarted(9 reactors,as of August 2019).In this study,the amount of curtailment for solar PV in the Kyushu area is sent to the Chugoku area using the cross-regional interconnector(Kanmon line).Then,the PHES in the Chugoku area is pumping with low price.Because the spot price in the market is low when the curtailment is executed.After that,the PHES is generating at night with high price when the solar PV is not generating.It makes a profit by the deference for the cost of pumping and the revenue of generating by the PHES.As a calculation result,for one week from May 2nd to 8th,2019,a profit becomes 152.2 million JPY(about 1.22 million EUR).For this purpose,it is necessary to raise the operation capacity of the cross-regional interconnector up to the rated capacity with the frequency control function of solar PV instead of the capacity to keep frequency in the event of an accident.This will allow the further introduction of solar PV in Japan.

Influence of Interconnection Configuration on Thermal Dissipation of ULSI Interconnect Systems

The effects of adjacent metal layers and space between metal lines on the temperature rise of multilevel ULSI interconnect lines are investigated by modeling a three-layer interconnect. The heat dissipation of various metallization technologies concerning the metal and low-k dielectric employment is simulated in detail. The Joule heat generated in the interconnect is transferred mainly through the metal lines in each metal layer and through the path with the smallest thermal resistance in each Ield layer. The temperature rises of Al metallization are approximately pAl/pCu times higher than those of Cu metallization under the same conditions. In addition, a thermal problem in 0.13μm globe interconnects is studied for the worst case, in which there are no metal lines in the lower interconnect layers. Several types of dummy metal heat sinks are investigated and compared with regard to thermal efficiency,influence on parasitic capacitance,and optimal application by combined thermal and electrical simula- tion.

DESIGN AND IMPLEMENTATION OF A GIGABIT PER SECOND OPTICAL INTERCONNECTION DATA LINK

The interconnection network is one of the key elements of distributed computing systems such as MPP (massively parallel processing) or NOWs (network of workstations).In this paper,a high speed optical interconnection data link which has been designed and implemented is presented.Using TDM (time division multiplexing),virtual parallel synchronous data transmission between the PCI buses of two computers has been achieved.The maximum data rate of the link is 1 250 Mbit/s,and the communication distance of link is more than 600 m using multi mode fibers.The design method of the high frequency electrical signals on the network interface card has been analyzed,and the efficient data transmission bandwidth of the link in different transmission modes has been tested and analyzed.

Dynamic load balancing based on restricted multicast tree in triplet-based hierarchical interconnection network

To solve the load balancing problem in a triplet-based hierarchical interconnection network（THIN） system, a dynamic load balancing （DLB）algorithm--THINDLBA, which adopts multicast tree （MT）technology to improve the efficiency of interchanging load information, is presented. To support the algorithm, a complete set of DLB messages and a schema of maintaining DLB information in each processing node are designed. The load migration request messages from the heavily loaded node （HLN）are spread along an MT whose root is the HLN. And the lightly loaded nodes（LLNs） covered by the MT are the candidate destinations of load migration; the load information interchanged between the LLNs and the HLN can be transmitted along the MT. So the HLN can migrate excess loads out as many as possible during a one time execution of the THINDLBA, and its load state can be improved as quickly as possible. To avoid wrongly transmitted or redundant DLB messages due to MT overlapping, the MT construction is restricted in the design of the THINDLBA. Through experiments, the effectiveness of four DLB algorithms are compared, and the results show that the THINDLBA can effectively decrease the time costs of THIN systems in dealing with large scale computeintensive tasks more than others.

Accurate Interconnection Length and Routing Channel Width Estimates for FPGAs

We study the problem of the prediction of interconnection dimensions for FPGAs, including estimating interconnection length and channel width. Experimental results show that our estimates are more accurate than those of existing methods.

Development of Network Interconnection in China

This paper introduces the current situation of China power industry and interconnection, the necessity to develop interconnection, the principle of nationwide interconnection and the key technologies to be studiedinclude HVDC and FACTS. The paper also discusses thefeasibility of 750 kV to be used in the northwest.regionand to speed up research and development of nighervoltage level in other regions of China, as well as scl-ence and technical innovation for transmission and dis-tribution projects.

USING WAVELENGTH ROUTING IN THE OPTICAL INTERCONNECTION COMPUTER NETWORK

The wavelength routing technology applied to computer interconnection networks is introduced in this paper.By analyzing the relation between wavelength and network routing,we describe a concept of wavelength used as network IP address,and propose a wavelength routing topology to extend the scale of a network and realize the scalability of the network.Moreover,a twin wavelength ring network that is being developed in our laboratory to implement and test the function of wavelength routing is presented,and the main units of the twin wavelength ring network are presented also.According to the testing results based on a single wavelength ring network,it proves that the optical interconnection technology is a perfect technology to provide enough communication bandwidth for computer network.

Cross-regional emergency scheduling planning for petroleum based on the supernetwork model

Petroleum, the most important energy source in the world, plays an essential role in securing economic development. If a petroleum shortage happens, it will severely disrupt production and life. Cross-regional emergency scheduling can effectively alleviate a petroleum shortage and further enhance the efficiency of the emergency response. Considering the general lack of focus on cross-regional petroleum dispatching management, we propose a three-layer emergency scheduling network for petroleum based on a supernetwork model that can increase the regional emergency correlation by adding a transfer management process. Then, we compare the total demand for petroleum and the emergency costs considered in the petroleum emergency scheduling supernetwork model（the single-region and the cross-region scenarios）.The result shows that the cross-regional emergency scheduling pattern can effectively enhance the efficiency of the emergency preparations and reduce the emergency costs in most cases. However, when the vulnerabilities in the crossregional link grow or the regional linkage decreases, the effect of single-regional scheduling is better. In addition, the advantages of the cross-regional emergency scheduling network will be strengthened with an increase in its maximum emergency capability. Nonetheless, this advantage will disappear when the petroleum demand in the crisis layer reaches the maximum emergency response capacity. Finally, according to the comparative analysis simulation among scenarios,certain strategic policy recommendations are suggested to improve the petroleum emergency scheduling ability in regions.These recommendations include strengthening the cross-regional coordination mechanism, increasing the modes of petroleum transportation and enhancing the carrying capacity of regional emergency routes.

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.

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.

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.

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.

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.

Layout Planning Technology of Cellular Manufacturing System Based on Process Interconnection Analysis

With sustaining change of production mode,layout planning is no longer a thing built once for all.Cellular layout(CL) is becoming a hotspot in the research field of manufacturing system layout.Traditional researches on layout planning are mainly concentrating on aspects of layout arithmetic,style and evaluation,etc.Relatively seldom efforts are paid to CL and its specific problems as cell formation(CF),equipment sharing and CL analysis.Through problem analyzing of layout in cellular manufacturing system(CMS),research approach of cell formation,interactive layout and layout analysis threaded with process interconnection relationship(PIR) is proposed.Typical key technologies in CL like CF technology based on similarity analysis of part processes,interactive visual layout technology,layout evaluation technology founded on PIR analysis and algorithm of cell equipment sharing are put forward.Against the background of one enterprise which encounters problems of low utility of key equipments and disperse material logistic,an example of four-cell layout is given.The CL adjustment and analysis results show that equipment with high level of sharing degree should be disposed around the boundary of its main cell,and be near to other sharing cells as possible; process route should be centralized by all means,so equipment adjustment is to be implemented along direction that route intersection can be decreased; giving consideration to the existence of discrete cell,logistic route and its density should be centralized to cells formed.The proposed research can help improve equipment utility and material logistic efficiency of CL,and can be popularized to other application availably.

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.

The Development of cross border interconnection and trading

This paper discusses the ben efits of developing cross border in tercon nection. It was writte n to promote the ben efits of interc on nectio n to facilitate ren ewable en ergy developme nt and trading. It illustrates the assessme nt of the ben efit with coupling between two power systems with an example importing renewable energy. The strategy for the development of European wide in tercon necti on to level prices is described together with the trading arrangeme nts. The process to evaluate the pote ntial for new intercon nectio n investment is outli ned together with a discussi on of the tech no logy options. The paper concludes with an illustration of the arrangements for cross border trading.