Multi-disciplinary virtual prototypes of complex products are increasingly and widely used in modern advanced manufactur- ing. How to effectively address the problems of unified modeling, composition and reuse based o...Multi-disciplinary virtual prototypes of complex products are increasingly and widely used in modern advanced manufactur- ing. How to effectively address the problems of unified modeling, composition and reuse based on the multi-disciplinary heteroge- neous models has brought great challenges to the modeling and simulation （M＆S） science and technology. This paper presents a top-level modeling theory based on the meta modeling framework （M2F） of the COllaborative SIMulation （COSlM） theory of virtual prototyping to solve the problems. Firstly the fundamental prin- ciples of the top-level modeling theory are decribed to expound the premise, assumptions, basic conventions and special require- ments in the description of complex heterogeneous systems. Next the formalized definitions for each factor in top level modeling are proposed and the hierarchical nature of them is illustrated. After demonstrating that they are self-closing, this paper divides the top- level modeling into two views, static structural graph and dynamic behavioral graph. Finally, a case study is discussed to demon- strate the feasibility of the theory.展开更多
随着新型电力系统加快构建,虚拟电厂(virtual power plant,VPP)作为新型能源体系中的关键组成,为电力系统安全保供和节能降碳提供了重要支撑。然而,虚拟电厂的技术形态和应用场景愈发多元,规模化发展存在标准化制约,及时总结和归纳虚拟...随着新型电力系统加快构建,虚拟电厂(virtual power plant,VPP)作为新型能源体系中的关键组成,为电力系统安全保供和节能降碳提供了重要支撑。然而,虚拟电厂的技术形态和应用场景愈发多元,规模化发展存在标准化制约,及时总结和归纳虚拟电厂的发展理念、建设路径和技术实践,将有利于推动技术协同和行业发展。鉴于此,该文以超大城市虚拟电厂为典型用例,首先从形式、政策、市场以及标准4个方面进行归纳梳理,详细讨论了虚拟电厂顶层设计理念。其次,从精准响应、区域协同、快速调频3个维度探究了虚拟电厂多时空调控技术体系,支持上海虚拟电厂常态化运营。然后,介绍了上海市VPP规模化示范应用成效,可为超大城市级虚拟电厂的发展建设和创新实践提供参考。最后,通过对上海市虚拟电厂建设运营前景分析,凝练出其发展路径。展开更多
Network processors (NPs) are widely used for programmable and high-performance networks;however, the programs for NPs are less portable, the number of NP program developers is small, and the development cost is high. ...Network processors (NPs) are widely used for programmable and high-performance networks;however, the programs for NPs are less portable, the number of NP program developers is small, and the development cost is high. To solve these problems, this paper proposes an open, high-level, and portable programming language called “Phonepl”, which is independent from vendor-specific proprietary hardware and software but can be translated into an NP program with high performance especially in the memory use. A common NP hardware feature is that a whole packet is stored in DRAM, but the header is cached in SRAM. Phonepl has a hardware-independent abstraction of this feature so that it allows programmers mostly unconscious of this hardware feature. To implement the abstraction, four representations of packet data type that cover all the packet operations (including substring, concatenation, input, and output) are introduced. Phonepl have been implemented on Octeon NPs used in plug-ins for a network-virtualization environment called the VNode Infrastructure, and several packet-handling programs were evaluated. As for the evaluation result, the conversion throughput is close to the wire rate, i.e., 10 Gbps, and no packet loss (by cache miss) occurs when the packet size is 256 bytes or larger.展开更多
在碳中和的背景下,作为一种无污染的可再生能源,氢能在能源转型中占据着越来越重要的地位。传统的氢电耦合直流微电网设计方案中,制氢设备并联嵌入直流微网,并作为一种灵活性负载参与系统调控以平替部分储能的功能。但是碱液电解槽(alka...在碳中和的背景下,作为一种无污染的可再生能源,氢能在能源转型中占据着越来越重要的地位。传统的氢电耦合直流微电网设计方案中,制氢设备并联嵌入直流微网,并作为一种灵活性负载参与系统调控以平替部分储能的功能。但是碱液电解槽(alkaline water electrolyzer,AWE)具有低压大电流的特点。随着直流微电网电压等级的提升,传统的并联结构一方面增加了电力电子装置的电压转换比的需求,另一方面忽略了碱液电解槽的电热特性。针对以上问题,该文提出了一种基于虚拟热敏电阻的串联型氢电耦合直流微电网稳定控制策略。首先,针对碱液电解槽建立了一套等效电热模型以表征最大电流与温度的关系。在此基础上,提出了一种电堆串联结构的碱液电解制氢模块(series-connectedstacks alkaline water electrolysis module,SAWEM)及其控制策略。串联结构能降低单个电堆输入电压,而虚拟热敏电阻控制策略能实现各电堆间精确合理的功率分配,且对直流微网有功率支撑作用。最后,通过简易的光伏制氢硬件实验平台进行了验证,结果表明该控制方法具有良好的实用性和有效性。展开更多
基金supported by the National High Technology Research and Development Program (863 Program) (2011AA040502).
文摘Multi-disciplinary virtual prototypes of complex products are increasingly and widely used in modern advanced manufactur- ing. How to effectively address the problems of unified modeling, composition and reuse based on the multi-disciplinary heteroge- neous models has brought great challenges to the modeling and simulation （M＆S） science and technology. This paper presents a top-level modeling theory based on the meta modeling framework （M2F） of the COllaborative SIMulation （COSlM） theory of virtual prototyping to solve the problems. Firstly the fundamental prin- ciples of the top-level modeling theory are decribed to expound the premise, assumptions, basic conventions and special require- ments in the description of complex heterogeneous systems. Next the formalized definitions for each factor in top level modeling are proposed and the hierarchical nature of them is illustrated. After demonstrating that they are self-closing, this paper divides the top- level modeling into two views, static structural graph and dynamic behavioral graph. Finally, a case study is discussed to demon- strate the feasibility of the theory.
文摘随着新型电力系统加快构建,虚拟电厂(virtual power plant,VPP)作为新型能源体系中的关键组成,为电力系统安全保供和节能降碳提供了重要支撑。然而,虚拟电厂的技术形态和应用场景愈发多元,规模化发展存在标准化制约,及时总结和归纳虚拟电厂的发展理念、建设路径和技术实践,将有利于推动技术协同和行业发展。鉴于此,该文以超大城市虚拟电厂为典型用例,首先从形式、政策、市场以及标准4个方面进行归纳梳理,详细讨论了虚拟电厂顶层设计理念。其次,从精准响应、区域协同、快速调频3个维度探究了虚拟电厂多时空调控技术体系,支持上海虚拟电厂常态化运营。然后,介绍了上海市VPP规模化示范应用成效,可为超大城市级虚拟电厂的发展建设和创新实践提供参考。最后,通过对上海市虚拟电厂建设运营前景分析,凝练出其发展路径。
文摘Network processors (NPs) are widely used for programmable and high-performance networks;however, the programs for NPs are less portable, the number of NP program developers is small, and the development cost is high. To solve these problems, this paper proposes an open, high-level, and portable programming language called “Phonepl”, which is independent from vendor-specific proprietary hardware and software but can be translated into an NP program with high performance especially in the memory use. A common NP hardware feature is that a whole packet is stored in DRAM, but the header is cached in SRAM. Phonepl has a hardware-independent abstraction of this feature so that it allows programmers mostly unconscious of this hardware feature. To implement the abstraction, four representations of packet data type that cover all the packet operations (including substring, concatenation, input, and output) are introduced. Phonepl have been implemented on Octeon NPs used in plug-ins for a network-virtualization environment called the VNode Infrastructure, and several packet-handling programs were evaluated. As for the evaluation result, the conversion throughput is close to the wire rate, i.e., 10 Gbps, and no packet loss (by cache miss) occurs when the packet size is 256 bytes or larger.
文摘在碳中和的背景下,作为一种无污染的可再生能源,氢能在能源转型中占据着越来越重要的地位。传统的氢电耦合直流微电网设计方案中,制氢设备并联嵌入直流微网,并作为一种灵活性负载参与系统调控以平替部分储能的功能。但是碱液电解槽(alkaline water electrolyzer,AWE)具有低压大电流的特点。随着直流微电网电压等级的提升,传统的并联结构一方面增加了电力电子装置的电压转换比的需求,另一方面忽略了碱液电解槽的电热特性。针对以上问题,该文提出了一种基于虚拟热敏电阻的串联型氢电耦合直流微电网稳定控制策略。首先,针对碱液电解槽建立了一套等效电热模型以表征最大电流与温度的关系。在此基础上,提出了一种电堆串联结构的碱液电解制氢模块(series-connectedstacks alkaline water electrolysis module,SAWEM)及其控制策略。串联结构能降低单个电堆输入电压,而虚拟热敏电阻控制策略能实现各电堆间精确合理的功率分配,且对直流微网有功率支撑作用。最后,通过简易的光伏制氢硬件实验平台进行了验证,结果表明该控制方法具有良好的实用性和有效性。
