A Novel Simulation Method for Power Electronics: Discrete State Event Driven Method

In the analysis of power electronics system,it is necessary to simulate ordinary differential equations(ODEs)with discontinuities and stiffness.However,there are many difficulties in using traditional discrete-time algorithms to solve such equations.Kofman and others presented the quantized state systems(QSS)algorithm in the discrete event system specification(DEVS)formalism.The discretization is applied to the state variables instead of time range in QSS.QSS is efficient to solve ODEs,but it is difficulty to be used when simulating actual power electronics systems with controller’s and other events.Based on the idea of this numerical algorithm and discrete event,a Discrete State Event Driven(DSED)simulation method is presented in this paper,which is fit for simulation of power electronics system.The method is developed to deal with non-linearity,stiffness and multi-time scale of power electronics systems.The DSED simulation method includes event definition,module seperation and modeling,event-driven mechanisms,numerical computation based on QSS,and some other operations.Simulation results verified the effectiveness and validity of the proposed method.

Event-driven process execution model for process virtual machine

Current orchestration and choreography process engines only serve with dedicate process languages.To solve these problems,an Event-driven Process Execution Model(EPEM) was developed.Formalization and mapping principles of the model were presented to guarantee the correctness and efficiency for process transformation.As a case study,the EPEM descriptions of Web Services Business Process Execution Language(WS-BPEL) were represented and a Process Virtual Machine(PVM)-OncePVM was implemented in compliance with the EPEM.

Optimal switching policy for performance enhancement of distributed parameter systems based on event-driven control

This paper aims to improve the performance of a class of distributed parameter systems for the optimal switching of actuators and controllers based on event-driven control. It is assumed that in the available multiple actuators, only one actuator can receive the control signal and be activated over an unfixed time interval, and the other actuators keep dormant. After incorporating a state observer into the event generator, the event-driven control loop and the minimum inter-event time are ultimately bounded. Based on the event-driven state feedback control, the time intervals of unfixed length can be obtained. The optimal switching policy is based on finite horizon linear quadratic optimal control at the beginning of each time subinterval. A simulation example demonstrate the effectiveness of the proposed policy.

Smart home architecture based on event-driven DPWS～+

With the advances of electronic information technology and computer network, especially the embedded technology, smart home is no more just a vision but being practical. The interoperability of heterogeneous devices and flexibility of devices＇ usage are two key problems that challenge the implementation of smart home. To deal with these two issues, this paper proposes an event-driven service oriented architecture using device profile for web services （DPWS）. DPWS inherits the advantages of the traditional web services in achieving interoperability without dependence on platform, while improving service discovery and security as well as being optimized for deploying on resource constrained devices. By providing a visual interface for describing a service workflow （SW）, the user can easily customize the actions of devices by services composition. Devices automatically cooperate without user＇s intervention to complete required business logic. This is achieved by fully exploiting the eventing capabilities on DPWS enabled home devices. Finally, a home theater scenario is given to illustrate the event driven mechanism for the SW in the proposed smart home framework.

Internet-based event synchronization communication driven telerobotics

Based on QoS (quality of service) parameters: time delay, jitter, bandwidth and package loss. As time delay in the Internet is variable, it is hard to compensate it by traditional methods. Event synchronization communication driven method is proposed to overcome the negative effects induced by time delay. This method is a non-time based method and it can get rid of the effects of time in the control loop of telerobotics. Stability, transparency and synchronization can be maintained in it by event-driven method. Multimodal enhanced telerobotics is put forward with its feedback including force, video, audio and temperature etc. The use of multimodal feedback improves the efficiency and safety of the whole system. Synchronization in multimodal feedback is hard to ensure and event-driven method is also good for it. Experiments on an Internet-based shaft-hole assemblage system show good results by using event synchronization communication driven method and UDP protocol.

Event-driven timing system based on MRF cPCI hardware for HLS-II

Hefei Light Source(HLS)-II is a vacuum ultraviole(VUV) synchrotron light source. A major upgrade of the light source was finished at the end of 2014. The timing system was rebuilt using compact peripheral component interconnect(cPCI) event-driven hardware to meet synchronization requirements of the machine. In the new system, the c PCI event-driven products manufactured by the micro-research finland(MRF) Oy are employed to achieve about 100 output signals with different interfaces. Device supports and drivers developed for common Experimental Physics and Industrial Control System(EPICS) records are used to access the registers on the timing modules. Five c PCI-bus input/output controllers(IOCs) distributed in different areas of the light source host timing modules for various subsystems. The delay resolution of this system is 9.8 ns for most channels and 9 ps for the channels used for triggering the electron gun and the injection kickers. The measured rms jitter of the output signal is less than 27 ps. Using the bucket chooser, this system enables the HLS-II to fill the storage ring with any designated bunch pattern. Benefitting from this upgrade, brightness and performance of the light source are significantly improved.

Discrete Event Simulation-Based Evaluation of a Single-Lane Synchronized Dual-Traffic Light Intersections

This research involved an exploratory evaluation of the dynamics of vehicular traffic on a road network across two traffic light-controlled junctions. The study uses the case study of a one-kilometer road system modelled on Anylogic version 8.8.4. Anylogic is a multi-paradigm simulation tool that supports three main simulation methodologies: discrete event simulation, agent-based modeling, and system dynamics modeling. The system is used to evaluate the implication of stochastic time-based vehicle variables on the general efficiency of road use. Road use efficiency as reflected in this model is based on the percentage of entry vehicles to exit the model within a one-hour simulation period. The study deduced that for the model under review, an increase in entry point time delay has a domineering influence on the efficiency of road use far beyond any other consideration. This study therefore presents a novel approach that leverages Discrete Events Simulation to facilitate efficient road management with a focus on optimum road use efficiency. The study also determined that the inclusion of appropriate random parameters to reflect road use activities at critical event points in a simulation can help in the effective representation of authentic traffic models. The Anylogic simulation software leverages the Classic DEVS and Parallel DEVS formalisms to achieve these objectives.

运用一站式智能导医平台改善患者就医体验

智能导医是医院智慧服务的重要组成部分。上海市胸科医院借助事件驱动和人工智能技术,以微信公众号为载体,构建了一站式智能导医平台,根据不同患者门诊就医需求,制订个体化就医规划,以任务流形式串联各就诊环节,缩短了患者候诊时间,缓解了导医工作压力,改善了患者就医体验。

基于事件驱动的数字孪生太浦河“四预”业务应用

聚焦太湖流域多目标统筹调度特点,通过多源数据融合汇聚太浦河各类涉水信息,构建符合平原感潮地区特点的太浦河高精度数据底板,优化流域水量水质模型算法,对太浦河防洪及供水业务进行流程再造,建成以事件为驱动的数字孪生太浦河“四预”业务系统。系统在“梅花”“杜苏芮”等台风防御中对太浦闸不同调度方式下洪水变化过程和淹涝情况进行了预演,发挥了重要支撑作用。在上海市抗咸潮保供水工作中,滚动预报重要断面水量水质,强化补水水质安全预警,确保太浦河上游水源地持续稳定供水。

事件驱动的云原生应用软件研究

事件驱动是云原生应用的主要驱动力,是实时敏捷数字业务的核心。通过侦听物联网设备、移动应用程序、业务网络和用户行为等事件源,捕获业务事件,驱动服务。事件的捕获、通信、转换和持久化是关键,可以扩展、适配不同类型的服务。消息队列是异步的,消息的发送和接收者不需要同时与消息队列交互,减少了服务间的耦合;如果系统请求流量瞬时剧增,消息队列将缓存请求,提高系统的稳定性和用户体验;事件溯源可以回溯到任何一个事件状态,增强系统的可靠性和容错。CloudEvents是描述事件数据通用格式的规范,提供跨服务、平台和系统的互操作。基于主题和分区将事件路由到不同的服务实例实现分布式并发。事件驱动架构融合微服务和无服务器函数,构建实时、可扩展、高负载和大规模可伸缩的云原生应用软件。

考虑源荷不确定性及用户响应行为的电力系统低碳经济调度

电力系统是未来实现碳中和目标的重要领域,随着源-荷不确定性的加剧,基于确定性模型的低碳经济调度方法无法准确描述不确定因素对碳排放的影响。针对上述问题,该文首先从系统层面构建考虑不确定性的低碳鲁棒优化模型,利用概率模型对源荷不确定因素进行建模,并采用机会约束对目标满足期望的显著性水平进行描述,通过最大化不确定因素的置信水平得出风险规避策略下的鲁棒调度方案。接着从用户层面构建基于事件驱动的用户低碳响应模型,根据系统层计算结果,通过设定事件触发的碳排放阈值定义碳排放超额事件,并以价格形式引导用户的低碳用能行为。最后通过算例分析,验证所提模型能有效量化评估系统的低碳经济调度不确定性水平,充分发挥用户侧降碳能力,实现源荷双侧低碳目标的协同。

基于事件驱动深度强化学习的建筑热舒适控制

住宅暖通空调系统通常耗用大量能源,同时也极大地影响居住者的热舒适性。目前,强化学习广泛应用于优化暖通空调系统,然而这一方法需要投入大量时间和数据资源。为了解决该问题,提出了一个新的基于事件驱动的马尔可夫决策过程(event-driven Markov decision process,ED-MDP)框架,并在此基础上,提出了基于事件驱动的深度确定性策略梯度(event-driven deep deterministic policy gradient,ED-DDPG)方法,通过事件触发优化控制,结合强化学习算法求解最优控制策略。实验结果显示,与基准方法相比,ED-DDPG在提升学习速度和减少决策频率方面表现出色,并在节能和维持热舒适方面取得了显著成果。经过实验验证,该方法在优化住宅暖通空调控制方面展现出强大的鲁棒性和适应性。

基于事件驱动的超图卷积网络的谣言检测方法

依靠社交平台谣言传播链检测谣言是社交网络分析研究中的一个重要课题.但以往的研究大多将这个任务过度简化为依靠评论的传播链检测谣言,忽略了对现实世界新闻帖的复杂用户和事件交互的关注,难以捕捉到这些信息提供的潜在检测线索.针对该挑战,提出了一个事件驱动的超图卷积网络(event-driven hypergraph convolutional network,EHGCN),首次尝试将新闻、用户和事件建模在一个统一的超图卷积网络之中,以提升谣言检测性能.具体而言,基于用户的中心网络构建同质用户圈,以增强用户感知的谣言检测.此外,EHGCN联合利用事件内的主事件和子事件关联以及事件间的不一致性关联来进行谣言检测.在3个真实世界的数据集上进行的实验结果验证了EHGCN相较于现有方法在谣言检测方面的优势.研究也证实EHGCN可以通过获取丰富的用户社交圈和事件信息,在谣言传播早期及时发现谣言.

基于三幕结构思维链和语义自洽的事件驱动故事生成方法

事件驱动故事生成旨在根据有限的故事背景和事件信息生成连贯且符合事件内容的故事.然而,现有方法常因对复杂的事件关系推理不足,导致生成的故事存在语义不连贯、情节冲突等问题.为此,文中提出基于三幕结构思维链和语义自洽的事件驱动故事生成方法,在生成故事前选择类型多样的故事示例,学习不同类型故事的写作方式.生成故事时,按照故事的开端、冲突和结局三幕结构设计思维链,引导方法合理规划故事内容,避免故事情节前后矛盾.生成故事后,引入语义自洽,模拟作家的推敲过程,从生成的多个故事中选择语义一致、连贯性和相关性较高的故事.实验表明,相比提示学习方法,文中方法的BLEU-4和BERTScore指标值有所提升,并且在人工评估中也占有一定的优势.

告警诊断和预测技术研究综述

总结论述了基于图论的故障诊断和定位技术、基于软件定义网络(Software Defined Network,SDN)架构的故障诊断和恢复技术、基于故障追踪的故障预测方法、基于事件驱动的故障预测方法。从故障诊断方法的优点、缺点进行对比分析,从故障预测的模型输入、应用范围、优点和不足等方面进行对比分析,对发展趋势进行分析总结,以实例验证了所总结的故障诊断和预测方法。

源-荷-储协同优化的配电网平衡能力提升方法

在新型电力系统建设背景下,针对分布式新能源和柔性负荷大量接入导致配电网供需情况日益复杂、功率和能量平衡愈加困难等问题,该文提出一种源-荷-储协同优化的配电网平衡能力提升方法,从经济性与用能低碳性等方面提高配电网运行水平。首先,建立多场景下的源荷不确定性模型,在有效量化配电网源荷不确定性的基础上提取典型运行场景;其次,提出一种基于信息熵理论的源荷功率时序平衡度量化评估方法;最后,建立源-荷-储协同的两阶段优化模型,第1阶段通过事件驱动机制深入挖掘用户参与需求响应的潜力,第2阶段在储能系统建模时引入平衡度约束以促进新能源消纳,进而使配电网的平衡能力得到最大程度提升。通过浙江某地区电网实例验证所提方法对提升配电网平衡能力和新能源消纳能力的科学性和实用性。

基于事件驱动的液流电池控制系统实现方式

液流电池具有充放电循环次数大、容量高及寿命长等优点,是长时大规模储能的理想选择,但是其复杂的结构对电池控制系统的要求较高,传统开发方式难以满足其多样的控制需求,因此提出精准度更高、实时性更好的基于事件驱动技术的液流电池控制系统开发方法。首先针对液流电池稳定性需求高、内部损耗大等问题,提出了主/辅助电堆协同架构,并对该架构系统进行建模分析;然后基于事件驱动技术对控制系统进行模块化设计,包括柔性充放电控制、辅助电堆参与的黑启动控制、基于卡尔曼滤波的电池荷电状态(state of charge,SOC)估计等;最后搭建半实物仿真平台,对所提架构和策略进行验证,证明了该架构和策略能提高系统的能量转换效率和稳定性。

基于服务的云边端协同流数据处理体系结构研究

物联网相关技术的快速发展产生了大规模传感流数据和对流数据的高并发处理需求,云边端协同计算正成为低延迟、高可靠的流数据处理的有效途径。为了提升流数据处理系统的灵活性和可扩展性,降低流数据处理延迟,本文提出一种基于服务的分散式云边端协同流数据处理体系结构,设计了面向大规模流数据的主动式数据服务模型,流数据及流数据处理被抽象为合适粒度、可被独立部署和动态调度的服务,解耦数据与计算。引入事件驱动机制,提出了基于事件驱动的云边端服务动态协作机制,有效提升了系统的灵活性。基于真实的电能质量传感流数据验证了本文所提出架构的正确性和有效性。

考虑最大通信量的物联网群体访问路由算法

针对因物联网群体用户访问数据量较大、访问频率不稳定,导致访问时延大、效率低的问题,提出一种基于事件驱动的访问路由算法予以解决。考虑到物联网群体数据动态特性强、难捕捉的问题,分析相邻访问节点位置信息、访问频率以及能耗变化与传输时延的关系。设置任意节点的簇首参数,通过物联网群体访问节点拓扑模型,计算簇首到访问点可容纳的最大通信量,作为路由算法的初始参照,采用事件驱动法将访问过程看作事件自然变动过程,结合实际负载情况,得到最终路由决策结果。实验结果表明,无论是干扰环境还是无干扰环境,所提路由算法的访问成功率均较高,且访问时延较低,具有一定的实用价值。