轨道交通“网-源-储-车”协同供能技术体系

为降低轨道交通系统牵引能耗,轨道交通“网-源-储-车”协同供能技术通过可再生能源的就地消纳,构建新型协同供能技术体系,实现跨时空高效用能.针对此新型供电系统结构,本文全面分析协同供能系统的物理架构、信息架构和社会架构的基本组成及类型特征;在此基础上,围绕资产能源化的基本概念,总结“荷-源”时空匹配评估方法与优化技术,并从系统角度阐述多源融合技术、保护重构、弹性评估等重要技术体系;重点分析“网-源-储-车”协同的高效能与高弹性的能源自洽技术,并基于人工智能和信息技术构建多层级能量管控系统,实现不同能量流的高效耦合,保障系统安全稳定经济运行.本文系统性地总结了轨道交通“网-源-储-车”协同供能系统的架构特征、评估优化、安全运维及协同运行等关键技术,阐述协同供能系统的技术组成体系,为协同供能系统的工程实践提供相应参考.

村民自组织供给乡村公共文化服务的影响因素研究--基于DQ镇5个村落的案例分析

村民自组织供给乡村公共文化服务是繁荣乡村公共文化进而实现乡村文化振兴的重要方式,主体构成、主体互动、时空布局、资源支撑、目标导向、激励、组织属性、外围环境、公共文化内容和成效获得等因素影响着此种供给方式的有效实现。通过精准把控供给方式内核、实现多元主体合力支撑、提供应有资源基础、营造良好外围环境和完善反馈与激励机制,能够进一步激发村民自组织供给乡村公共文化服务的最大效能。

Supply Chain Finance Credit Risk Evaluation Method Based on Self-Adaption Weight

Credit risk is the core issue of supply chain finance. In the supply chain, problems happened in different enterprises can influent the whole to different degrees through transferring, thus statuses of all enterprises and their different influences should be considered when evaluating the supply chain’s credit risk. We examine the characters of supply chain network and complex network, use the local growing complex network to simulate the real supply chain, use cluster analysis to classify the company into several levels;Introducing each level’s self-adaption weight formula according to the company’s quantity and degrees of this level and use the weight to improve the credit evaluation method. The research results indicate that complex network can be used to simulate the supply chain. The credit risk evaluation (CRE) of an enterprise level with bigger note degrees has a greater weight in the supply chain system’s CRE, thus has greater effect on the whole chain. Considering different influences of different enterprise levels can improve credit risk evaluation method’s sensitivity.

Improving Self-Supply of Urban Water and Sanitation Projects through Microfinancing in Nigeria

Most water and sanitation projects in poor neighbourhood of urban Nigeria are executed through self-supply option. This is defined as an incremental improvement of WASH products e.g. water and sanitation structures by a household or small group of households which are financed by their own effort and investment. It is indeed a concept which complements conventional water supply and sanitation funded by government. The aim of this paper is, therefore, to investigate the extent of the use of innovative financing especially group saving approach to improve water and sanitation projects in Awka town, Nigeria. Towards achieving the aim, data were collected through questionnaires which were designed and administered on the respondents between January and April, 2016 and from other secondary sources. Data were analyzed using Principal Component Analysis and Component scores to establish the extent of the use of this option in the 9 component quarters of the town. Result shows that some quarters have perfected using the self-supply option while in others, it is yet to be widely accepted. It is finally recommended among others that the urban water policy as well as urban water safety plan should be revised to include the option as a way of improving domestic water supply and sanitation in the town.

Multi-train modeling and simulation integrated with traction power supply solver using simplified Newton–Raphson method

Multi-train modeling and simulation plays a vital role in railway electrification during operation and planning phase. Study of peak power demand and energy consumed by each traction substation needs to be deter- mined to verify that electrical energy flowing in its railway power feeding system is appropriate or not. Gauss-Seidel, conventional Newton-Raphson, and current injection methods are well-known and widely accepted as a tool for electrical power network solver in DC railway power supply study. In this paper, a simplified Newton-Raphson method has been proposed. The proposed method employs a set of current-balance equations at each electrical node instead of the conventional power-balance equation used in the conventional Newton-Raphson method. This concept can remarkably reduce execution time and computing complexity for multi-train simulation. To evaluate its use, Sukhumvit line of Bangkok transit system （BTS） of Thai- land with 21.6-km line length and 22 passenger stopping stations is set as a test system. The multi-train simulation integrated with the proposed power network solver is developed to simulate 1-h operation service of selected 5-min headway. From the obtained results, the proposed method is more efficient with approximately 18 % faster than the conventional Newton-Raphson method and just over 6 % faster than the current injection method.

基于SICE自供电式压电-电磁俘能电路设计

对SICE接口电路的回收功率进行理论分析和计算,并利用Multisim对SHE、SECE、P-SSHI、S-SSHI和SICE 5种接口电路进行仿真和比较。通过对5种电路的分析,文中提出了一种基于同步翻转电荷提取的压电-电磁俘能电路(Self-Powered SICE)。所提出的电路由压电俘能部分、电磁供能部分、运算放大器、整流滤波电路、开关控制电路和同步翻转电荷提取电路组成。电磁产生的能量为开关控制电路供能,避免了引入额外的电源对开关进行控制以达到自供能。Multisim仿真结果表明本文设计的SP-SICE电路的回收功率是SHE电路的3.7倍,相比SICE电路的回收功率有所下降,但实现了自供电和负载的自适应。

Parameter Self - Learning of Generalized Predictive Control Using BP Neural Network

This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorithm was used for the training of the linking-weights of the neural network.Hence it gets rid of the difficulty of choosing these tuning-knobs manually and provides easier condition for the wide applications of GPC on industrial plants.Simulation results illustrated the effectiveness of the method.

Self - Crosslinking Behavior of Self - Emulsion Water - Based Polyure-thane Coating Agents

The relation between structures and properties of polyurethane are investigated by modern physical and chemical methods.The results obtained are as follows:the effects of the content of self-crosslinking agent on the properties of polyurethane,i.e.,dispersion stability,dynamical viscoelasticity and mechanical properties are discussed.It is found that the optimum molar ratio of epichlorohydrin and diethylenetriamine is 1:2.A mois-

Culture Self- Consciousness in Transmission of Chinese Philosophy from the Perspective of English Globalization -- Taking the Belt and Road Initiative for Example

The Belt and Road Initiative contains the aspiration of Chinese nation to pursue ideological freedom and desire of strengthening international exchanges and cooperation. This paper takes the Belt and Road Initiative for example,emphasizing the interpretation of the inheritance and development of Chinese culture so as to study the importance of Culture Self-Consciousness in Chinese Philosophy,in the context of English globalization. That is to say,this paper stresses the spirits and the stand of nation 's demonstration on pursuing peace,cooperation and sustainable development in the civilization continuity from traditional China to the contemporary China,with practical philosophic view.

Novel Cascade Refrigeration Cycle for Cold Supply Chain of COVID-19 Vaccines at Ultra-Low Temperature -80°C Using Ethane (R170) Based Hydrocarbon Pair

Several media report highlight on that the pharmaceutical companies require ultra-low temperatures -80°C to transport and store its COVID-19 vaccines. This research presents the thermodynamic analysis on cascade refrigeration system (CRS) with several refrigerant pairs which are R32/R170, R123/R170, R134a/R170, R404A/R170, R407c/R170, R410/R170, and the hydrocarbon (HC) refrigerant pair Propane/Ethane, namely R290/R170. Besides, the results of R22/R170 pair, which is not recommended to be used due to phase out of R22 as per Montréal Protocol, are included as base case to compare the novel hydrocarbon pairs in CRS and the old trend of refrigerant pairs. Thermodynamic properties of all these pairs were investigated and compared under different intermediate temperature used in CRS heat exchanger, which thermally connected both the Low and High temperature cycles (LTC) and (HTC). By applying the first law of thermodynamics, the coefficients of performance (COPs) and the specific power consumptions (SPC) in kW/TR are presented and compared. In addition, by applying the second law of thermodynamics the exergetic efficiencies were estimated. The results reveal the promising opportunity of using the HC pair (R290/R170). The minimum SPC in kW/TR is recorded for the pair R123/R170. One the other hand, the highest exegetic efficiency values are observed to be 40%, 38%, and 35% for the pairs R123/R170, R290/R170, and R134/R170, respectively. This research concludes that the HC pair (R290/R170) is highly recommended for CRS applications either to transport the COVID-19 or store it in cold storage rooms in hospitals and clinics. All precautionary measures should be carefully applied in design and operation of HC pair (R290/R170) due to its flammability hazard.

完善生鲜农产品供应链的理论和政策研究

我国轻商的观念由来已久,但城乡居民日常需要的生鲜食品高度依赖从事生鲜农产品经营的商贩,他们是生鲜农产品供应链主体的组成部分,在促进生鲜农产品区域分工深化、贴近民生方面发挥着重要作用,对产业集群、供应链冷链、物流园区、旅游、住宿、餐饮就业都具有强烈多向性的带动作用,是各地经济发展的隐形间接影响力、软实力。必须改变长期存在的重场所建设、轻主体培育的顽疾;培育生鲜农产品供应链的链主企业,促进供应链分工的深化和专业化;加强对违法违规行为的监管,共促诚实守信公平竞争的营商环境;对生鲜农产品市场实施反周期调控;严格大棚与大田生鲜农产品的行为监管标准;将市场调控的重心从事后的被动跟进管理,转变为事前的主动引导服务;探索“有效市场+有为政府”的管理模式,创新逆周期监测调控的有效办法;把握生鲜农产品供应链高质量发展的舆论导向,为商人正名;警惕出现重生产、轻流通新的倾向和新的表现形式,防止损害现代流通体系、统一大市场建设。

一种放电打火保护电路的设计

直流高压电源在制造及使用的过程中经常由于放电打火产生突变输出而损坏电源内部器件,进而造成频繁的维修更换。为解决这一问题,设计了一种用于直流高压电源的放电打火保护电路,可通过互感原理检测电源电路中出现的放电打火故障,并由保护电路产生放电打火信号,使可控硅与继电器工作,通过减法器电路实现高压电源输出的突变抑制,从而使得高压电源输出维持在安全电压值,并且可通过继电器调节抑制持续时间,时间结束后电压自动恢复到初始设定值。结果表明,放电打火检测装置电路结构合理、灵敏可靠,在实现放电打火保护功能的同时满足自恢复要求,为电源电路系统的安全运行提供了有力保障。

模块化多电平中压直流变换器的高可靠自供电架构研究

随着大容量中压直流配电技术的迅速发展,模块化多电平直流变换器受到工业界和学术界的广泛关注。然而,实现高可靠的辅助供电是实现直流变换器在中压直流配电场景中应用的关键技术瓶颈之一。为此,提出一种面向模块化多电平中压直流变换器的高可靠自供电系统架构。该架构实现主控制器、子模块等辅电系统的中压直联馈电,从而无需额外低压直流电源,并且大幅提升系统启动速度。基于此架构设计,模块化多电平直流变换器的子模块控制器和旁路开关辅助供电均实现3倍冗余,提高系统容错运行的能力。在子模块电容预充电阶段,提出一种基于辅助电源自主控制的子模块电容均压方法,保证模块化多电平直流变换器可靠预充电。最终通过实验验证所提辅助供电系统架构的可行性。

牵引供电数字孪生系统框架设计及典型应用

数字孪生是一种将物理实体与数字模型深度融合的新兴产业技术,受到国内外铁路行业广泛关注。基于数字孪生的概念和发展现状,提出牵引供电数字孪生系统的框架设计和关键技术需求。针对基于数字孪生的牵引变压器状态监测及性能预测、牵引开关柜温度监测、系统故障检测与处理等典型应用,探讨数字孪生技术在铁路牵引供电系统领域的应用前景。结果表明,通过数字孪生技术的应用,可实现对设备运行状态的全面监测和优化,提升牵引供电系统的性能及可靠性。

“双碳”目标下民用建筑用户侧储能应用展望与策略

探索“双碳”目标下民用建筑用户侧储能应用前景和应用策略,分析建筑用户侧储能安全性等问题,探讨建筑光储直柔、储能创新技术的推广应用,并提出利用用户侧储能构建多样性自备电源的策略。

基于GOOSE通信的城市轨道交通直流牵引供电系统双边联跳与自愈方案

[目的]城市轨道交通直流牵引供电系统的结构复杂且无备用,一旦故障将直接引发停车事故。针对传统牵引供电系统双边联跳方案在实际工程中暴露出的不足,以及直流牵引供电系统智能化程度较低的现状,需研究出利用智能化手段提高直流牵引供电系统双边联跳可靠性的方案。[方法]提出了一种基于GOOSE(面向通用对象的变电站事件)通信的直流牵引供电系统双边联跳与自愈方案。该方案在直流牵引供电系统内构建了GOOSE过程层通信网络,通过牵引变电所内及牵引变电所间各类信息的快速实时交换实现了直流牵引供电系统的双边联跳与自愈重构。对所提出的方案进行了实验室模拟与现场验证。[结果及结论]基于GOOSE通信的城市轨道交通直流牵引供电系统双边联跳与自愈方案具有更高的可靠性与实时性,且方案智能化程度较高,可进行推广应用。

浮式平台多用途供水系统设计

文章分析了常规水泵系统设计方案的优缺点及适应性,针对在特殊型式的浮式平台中常规方案无法满足设计要求的问题,提出了使用长轴泵系统及自吸泵系统的解决方案,给出相应的系统计算方法和设计要点,包括系统控制逻辑、管系设计、阀门类型、泵吸入性能计算、防汽蚀措施及设备布置方案等,为各类浮式平台及船舶的供水系统设计提供了参考。

新型本质安全电源保护电路设计

为了解决本安电源过流和短路的安全问题,设计了一种用于本质安全电源的新型保护电路。该电路通过电流镜电路按一定的比例复制主路电流,并由副电路采样电流信号,经过放大、移位处理后接入比较器负输入端,比较器正输入端接入短路检测信号。该新型电路的功能是当电源负载发生过流或短路故障时,滞回比较器输出过流或短路控制信号,迅速关断主电流开关,从而实现对负载主电路截断的保护;同时启动微电流开关,检测短路故障是否消除,使得故障消除后能够自动恢复主电流开关电路。此外,电源保护电路的软启动电路可用于解决电源启动过程中的浪涌电流可能会造成过流保护误动作的问题。

自走式果园喷雾机设计与试验

针对新疆果园喷雾施药作业劳动强度大、雾滴穿透性差、机具适用范围小等问题,结合果园农机农艺及病虫害防治要求,设计了一款自走式果园喷雾机,主要由履带式行走系统、喷雾系统和远程控制系统等组成。通过计算分析确定各部分主要结构参数,并通过有限元模拟分析机架结构合理性。为验证喷雾机作业性能,以喷头流量为试验因素,以喷雾附着率与喷雾穿透性为试验指标,针对整机喷杆喷雾装置与风送喷雾装置开展田间试验。结果表明:在相同工作条件下,喷杆式喷雾装置平均喷雾附着率高于风送式喷雾装置,两种喷雾装置平均喷雾附着率分别为71.99%与66.35%,均能满足喷雾附着要求。在穿透性试验中,风送式喷雾装置内外冠层药液沉积变异系数平均比喷杆式喷雾装置小14%,风送式喷雾装置穿透性明显强于喷杆式喷雾装置。喷雾机两种喷雾装置在附着率与穿透性上都有较好的作业效果,可根据果树不同生长时期以及不同农艺需求选择适合的喷雾方式,来达到更好的喷雾效果。

基于自营海外仓+平台服务的跨境电商模式构建研究

新业态背景下,跨境电商平台和海外仓网络布局体系的共通发展给予跨境电商中小企业转型升级的新机遇。本文以浙江宁波跨境电商企业拓展海外市场的进程为基础,构建自营海外仓+平台服务的跨境电商模式,细化该模式下的基础服务、数字服务、物流服务、金融服务,并对该模式下的具体企业案例进行研究,实现自营海外仓和跨境电商平台的共建,为跨境电商企业协同链路发展提供新思路。