In this paper the relation is derived between quasi-parabolic regulation and the rule of increasing oxygenpotential. Using these rules in Co-O binary system the stability of compounds CoO and Co_3O_4 is examined.
Heavy renewable penetrations and high-voltage cross-regional transmission systems reduce the inertia and critical frequency stability of power systems after disturbances.Therefore,the power system operators should ens...Heavy renewable penetrations and high-voltage cross-regional transmission systems reduce the inertia and critical frequency stability of power systems after disturbances.Therefore,the power system operators should ensure the frequency nadirs after possible disturbances are within the set restriction,e.g.,0.20 Hz.Traditional methods utilize linearized and simplified control models to quantify the frequency nadirs and achieve frequency-constrained unit commitments(FCUCs).However,the simplified models are hard to depict the frequency responses of practical units after disturbances.Also,they usually neglect the regulations from battery storage.This paper achieves FCUCs with linear rules extracted from massive simulation results.We simulate the frequency responses on typical thermal-hydro-storage systems under diverse unit online conditions.Then,we extract the rules of frequency nadirs after disturbances merely with linear support vector machine to evaluate the frequency stability of power systems.The algorithm holds a high accuracy in a wide range of frequency restrictions.Finally,we apply the rules to three typical cases to show the influences of frequency constraints on unit commitments.展开更多
Propelled by a combination of policy enablers,increasing investments,and the COVID-19 pandemic,the global financial technology(fintech) industry has entered a period of rapid growth in recent years.Yet it is important...Propelled by a combination of policy enablers,increasing investments,and the COVID-19 pandemic,the global financial technology(fintech) industry has entered a period of rapid growth in recent years.Yet it is important to note that poor regulation and weak supervision might produce risks and shocks to financial stability,business competition,social equity,and environmental resources.The encouraging approach toward fintech development adopted by major global economies over the past decade has ignored regulation to varying degrees,resulting in unbalanced and inadequate supervision,which has been falling short of meeting public concerns effectively.Since 2019,international discussions on how to regulate fintech have become more and more heated.It has been widely agreed that,to regulate fintech effectively,three pillars must be established—data,competition,and financial regulatory rules.Given the increasing challenges posed by large technology firms (big techs)to financial regulation,this paper proposes to prioritize entity-based regulation,with a focus on reforming the rules concerning operational resilience and competition.China should keep a close eye on international trends and learn to devise appropriate rules for entity-based regulation,which will prove necessary to guide the steady,sound,and sustainable development of its fintech industry.展开更多
Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand cu...Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country＇s borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases.展开更多
新能源渗透率的提高增加了电网频率控制的复杂度,储能辅助电网调频能在一定程度上缓解该问题,但受储能运行的安全性与经济性约束,要求调频措施更具针对性。文中对此展开研究,提出一种基于频率响应特性的储能辅助电网一次调频方法。首先...新能源渗透率的提高增加了电网频率控制的复杂度,储能辅助电网调频能在一定程度上缓解该问题,但受储能运行的安全性与经济性约束,要求调频措施更具针对性。文中对此展开研究,提出一种基于频率响应特性的储能辅助电网一次调频方法。首先,在储能辅助电网调频模型基础上,选择惯性加下垂的储能辅助电网调频综合控制方法,通过电网频率变化率(rate of change of frequency,RoCoF)、频率偏差与调频需求的关联性分析,设计基于频率响应特性的调频需求分区规则;然后,根据不同调频需求对应的分区判断,对储能有功输出方式进行动态调整,以响应调频需求的不确定性,并在此基础上,针对调频需求与储能出力需求、储能出力强弱与其循环使用寿命间的矛盾关系,通过多目标优化问题的设计与求解来予以平衡;最后,仿真结果验证了所提方法能够在保证电网调频效果的基础上,有效降低储能充放电深度。展开更多
文摘In this paper the relation is derived between quasi-parabolic regulation and the rule of increasing oxygenpotential. Using these rules in Co-O binary system the stability of compounds CoO and Co_3O_4 is examined.
基金supported by the research project from China Three Gorges Corporation(No.202103386).
文摘Heavy renewable penetrations and high-voltage cross-regional transmission systems reduce the inertia and critical frequency stability of power systems after disturbances.Therefore,the power system operators should ensure the frequency nadirs after possible disturbances are within the set restriction,e.g.,0.20 Hz.Traditional methods utilize linearized and simplified control models to quantify the frequency nadirs and achieve frequency-constrained unit commitments(FCUCs).However,the simplified models are hard to depict the frequency responses of practical units after disturbances.Also,they usually neglect the regulations from battery storage.This paper achieves FCUCs with linear rules extracted from massive simulation results.We simulate the frequency responses on typical thermal-hydro-storage systems under diverse unit online conditions.Then,we extract the rules of frequency nadirs after disturbances merely with linear support vector machine to evaluate the frequency stability of power systems.The algorithm holds a high accuracy in a wide range of frequency restrictions.Finally,we apply the rules to three typical cases to show the influences of frequency constraints on unit commitments.
文摘Propelled by a combination of policy enablers,increasing investments,and the COVID-19 pandemic,the global financial technology(fintech) industry has entered a period of rapid growth in recent years.Yet it is important to note that poor regulation and weak supervision might produce risks and shocks to financial stability,business competition,social equity,and environmental resources.The encouraging approach toward fintech development adopted by major global economies over the past decade has ignored regulation to varying degrees,resulting in unbalanced and inadequate supervision,which has been falling short of meeting public concerns effectively.Since 2019,international discussions on how to regulate fintech have become more and more heated.It has been widely agreed that,to regulate fintech effectively,three pillars must be established—data,competition,and financial regulatory rules.Given the increasing challenges posed by large technology firms (big techs)to financial regulation,this paper proposes to prioritize entity-based regulation,with a focus on reforming the rules concerning operational resilience and competition.China should keep a close eye on international trends and learn to devise appropriate rules for entity-based regulation,which will prove necessary to guide the steady,sound,and sustainable development of its fintech industry.
文摘Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country＇s borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases.
文摘新能源渗透率的提高增加了电网频率控制的复杂度,储能辅助电网调频能在一定程度上缓解该问题,但受储能运行的安全性与经济性约束,要求调频措施更具针对性。文中对此展开研究,提出一种基于频率响应特性的储能辅助电网一次调频方法。首先,在储能辅助电网调频模型基础上,选择惯性加下垂的储能辅助电网调频综合控制方法,通过电网频率变化率(rate of change of frequency,RoCoF)、频率偏差与调频需求的关联性分析,设计基于频率响应特性的调频需求分区规则;然后,根据不同调频需求对应的分区判断,对储能有功输出方式进行动态调整,以响应调频需求的不确定性,并在此基础上,针对调频需求与储能出力需求、储能出力强弱与其循环使用寿命间的矛盾关系,通过多目标优化问题的设计与求解来予以平衡;最后,仿真结果验证了所提方法能够在保证电网调频效果的基础上,有效降低储能充放电深度。
