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.

A Comprehensive Power Flow Approach for Multi-terminal VSC-HVDC System Considering Cross-regional Primary Frequency Responses

For the planning,operation and control of multiterminal voltage source converter(VSC)based high-voltage direct current(HVDC)(VSC-MTDC)systems,an accurate power flow formulation is a key starting point.Conventional power flow formulations assume the constant frequencies for all asynchronous AC systems.Therefore,a new feature about the complex coupling relations between AC frequencies,DC voltages and the exchanged power via VSC stations cannot be characterized if VSC-MTDC systems are required to provide cross-regional frequency responses.To address this issue,this paper proposes a comprehensive frequency-dependent power flow formulation.The proposed approach takes the frequencies of asynchronous AC systems as explicit variables,and investigates the novel bus models of the interlinking buses of VSC stations.The proposed approach accommodates different operation modes and frequency droop strategies of VSC stations,and considers the power losses of VSC stations.The effectiveness and generality of the developed approach are validated by a 6-terminal VSC-HVDC test system.The test system presents the characteristics of the coexistence of numerous VSC operation modes,the absence of slack buses in both AC and DC subsystems,and diversified grid configurations such as point-to-point integration of renewable energy sources and one AC system integrated with multiple VSC stations.

Multi-area Generation-reserve Joint Dispatch Approach Considering Wind Power Cross-regional Accommodation

This paper presents a study on how to accommodate wind power into multiple regions,while simultaneously implementing economic and reliable dispatch for multi-area power system operation.The focus is on quantifying the operational risk brought by wind power uncertainty and at the same time accommodating wind power by coordinating multi-area generation and reserve resources.The reserve requirement of each area is calculated based on two indexes,namely,loss of load probability and wind spillage probability.Then,a generation-reserve cooptimization dispatch model that factors cross-regional wind power accommodation is proposed.The transmission margin and network security constraints of tie-lines are considered to systematically allocate reserve resources for all areas.Finally,optimality condition decomposition is used to decompose the dispatching model to achieve relatively independent regional scheduling,and to get the global optimization result.The reasonableness and effectiveness of the proposed approach is validated by a 6-bus 2-area test system and a 236-bus interconnected system.

Multiperiod Optimal Allocation of Emergency Resources in Support of Cross-Regional Disaster Sustainable Rescue

Cross-regional allocation is necessary for the rational utilization and optimal allocation of resources.It is also the key to effective and sustainable disaster relief.Existing research,however,generally centers on emergency resource allocation only within territories or regions.This article proposes a multiperiod allocation optimization model for emergency resources based on regional selfrescue and cross-regional collaborative rescue efforts.The model targets the shortest delivery time and lowest allocation costs as its efficiency goals and the maximum coverage rate of resource allocation in the disaster-affected locations as its equity goal.An objective weighting fuzzy algorithm based on two-dimensional Euclidean distance is designed to solve the proposed model.A case study based on the Wenchuan Earthquake of 12 May 2008 was conducted to validate the proposed model.The results indicate that our proposed model allows for optimal,multiperiod cross-regional resource allocation by combining interterritorial and nearby allocation principles.Cross-regional relief makes resource allocation more equitable,minimizes dissatisfaction,and prevents losses.Different decision preferences appear to significantly affect the choice of resource allocation scheme employed,which provides flexibility for decision making in different emergencies.

Analysis on cross-regional scientific research collaboration model

Independent research is being promoted to the level of interdisciplinary and cross-regional scientific research collaboration,but the research on the latter is far less abundant than the former.Through systematic literature analysis,the current research topics on the status quo and performance evaluation of industry-university-research cooperation are revealed.The main methods are statistical analysis and network analysis.

Analysis of radiation diffusion of COVID-19 driven by social attributes

This paper first estimated the infectious capacity of COVID-19 based on the time series evolution data of confirmed cases in multiple countries. Then, a method to infer the cross-regional spread speed of COVID-19 was introduced in this paper, which took the gross domestic product(GDP) of each region as one of the factors that affect the spread speed of COVID-19 and studied the relationship between the GDP and the infection density of each region(China's Mainland, the United States, and EU countries). In addition, the geographic distance between regions was also considered in this method and the effect of geographic distance on the spread speed of COVID-19 was studied. Studies have shown that the probability of mutual infection of these two regions decreases with increasing geographic distance. Therefore, this paper proposed an epidemic disease spread index based on GDP and geographic distance to quantify the spread speed of COVID-19 in a region. The analysis results showed a strong correlation between the epidemic disease spread index in a region and the number of confirmed cases. This finding provides reasonable suggestions for the control of epidemics. Strengthening the control measures in regions with higher epidemic disease spread index can effectively control the spread of epidemics.

Multi-stage online task assignment driven by offline data under spatio-temporal crowdsourcing

In the era of the Internet of Things(IoT),the crowdsourcing process is driven by data collected by devices that interact with each other and with the physical world.As a part of the IoT ecosystem,task assignment has become an important goal of the research community.Existing task assignment algorithms can be categorized as offline(performs better with datasets but struggles to achieve good real-life results)or online(works well with real-life input but is difficult to optimize regarding in-depth assignments).This paper proposes a Cross-regional Online Task(CROT)assignment problem based on the online assignment model.Given the CROT problem,an Online Task Assignment across Regions based on Prediction(OTARP)algorithm is proposed.OTARP is a two-stage graphics-driven bilateral assignment strategy that uses edge cloud and graph embedding to complete task assignments.The first stage uses historical data to make offline predictions,with a graph-driven method for offline bipartite graph matching.The second stage uses a bipartite graph to complete the online task assignment process.This paper proposes accelerating the task assignment process through multiple assignment rounds and optimizing the process by combining offline guidance and online assignment strategies.To encourage crowd workers to complete crowd tasks across regions,an incentive strategy is designed to encourage crowd workers’movement.To avoid the idle problem in the process of crowd worker movement,a drop-by-rider problem is used to help crowd workers accept more crowd tasks,optimize the number of assignments,and increase utility.Finally,through comparison experiments on real datasets,the performance of the proposed algorithm on crowd worker utility value and the matching number is evaluated.

Regulating cost for renewable energy integration in power grids

To address the issue of climate change caused by the use of polluting, non-renewable energy sources, the use of renewable energy has gained momentum worldwide. Consequently, the increased integration of renewable energy sources into power grids has necessitated the inclusion of flexible capacities in the power systems to solve problems of intermittent and fluctuating characteristics associated with renewable generation outputs. In this work, we study the regulating cost of a power system with high renewable penetration using an improved time-series system production simulation analysis method. The operational cost of the system is considered as the objective function. Three different methods to increase regulating capacities, including using interconnection lines, building additional flexible power capacities, and retrofitting existing thermal power plants, are adopted and simulated to compare the costs of accommodating renewable energy in the system in these cases. Our results indicate that increasing the flexibility of thermal power plants and developing crossregional connection lines are cost-effective methods of increasing renewable energy consumption.

药品和耗材跨区域带量采购的实践与思考

目的比较我国药品和耗材跨区域带量采购的实践,厘清该模式的基本逻辑。方法比较分析国家组织集中采购(以下简称“国家集采”)和非国家集采框架下我国药品和耗材跨区域带量采购的实践,总结实践的基本特点,分析采购内容、采购环境及采购规则的内在关系。结果我国药品和耗材跨区域采购的实践包括:以国家组织药品集中采购和使用试点(以下简称“‘4+7’试点”),“4+7”试点扩围,第二、第三批国家组织药品集中采购和使用,深圳药品集中采购组织(group purchasing organization,GPO)模式为代表的药品带量采购;以京津冀联盟及由其发展而来的“3+6”联合采购模式,黔滇豫渝4省(直辖市)联盟以及陕西省牵头的15省(自治区、兵团)省(自治区、兵团)际联盟为代表的耗材带量采购;以三明联盟为代表的药品和耗材带量采购。实践特点是平台统一、信息共享,允许多家企业中标和价格差异,价格联动。结论跨区域带量采购将成为药品和耗材带量采购的主要模式,而合作共享的信息平台和科学合理的质量评价体系是重要保障。

Strengthening cross-region communication for mutual learning

From Oct 23 to 26 , the 21st National Work Conference for Exchanges Between Regional Associations for Friendship with Foreign Countries took place in Yinchuan, Ningxia Hui autonomous region. About 120 delegates of local foreign affairs offices (which also serve as local associations for friendship with foreign countries) from 21 provinces, municipalities and autonomous regions attended.After the opening ceremony.

应对重大疫情事件的跨区域联防联控机制探讨

It is essential for cross-regional control and treatment of major epidemics to establish a collaborative,efficient,and precise collective response mechanism.Based on the observation of the COVID-19 epidemic,this paper concludes major measures and experience of cross-regional collective response for epidemic control and treatment,compares the difference between localities at home and abroad,and puts forwards major strategies for a cross-regional collective response,hoping to provide policy-making references to improve the modernization level of public health,epidemic prevention,and emergency management in China.

Difference Among Similarity:A Study on Macao Students’Adjustment Experiences in Taiwan’s Higher Education Systems

Purpose:This study focused on cross-region student mobility to explore whether Macao students have adjustment issues while studying and living in Taiwan.Design/Approach/Methods:A total of 663 Macao students were surveyed in Taiwan,and the statistical methods,including correlation,t-test,analysis of variance,and hierarchical regression analysis were addressed to analyze the data.Findings:Macao students,even while studying in a Chinese context,did have social and psychological adjustment issues(i.e.,social support and self-efficacy).Originality/Value:This study could shed some light on understanding cross-region students as well as providing practical guides for relevant governmental departments in their policy regarding outbound students.