基于MSP430单片机的智能同步开关控制系统

介绍一种基于MSP430F449单片机的智能同步开关控制系统,该系统通过对电网的相电压、相电流进行采样,利用过零信号控制高压开关接通和断开的时间,使得开关的主触头分别在电压的过零点附近合上,在电流的过零点附近断开,消除容性负载的浪涌电流和感性负载的感应电压。     

两路输出的断电复位温控开关设计

基于双金属片受热翻转推动与之垂直的推杆,带动与推杆相连的动触片动作,进而接通另一路电源,设计一款两路输出的断电复位温控保护开关.为确保温控开关两路输出的可靠和负载用电安全,将第一路输出端子的功率电阻替换为嵌入PTC发热体,使负载电路因超温过载断开后,只能手动复位电路.     

我怎样上中学电子劳技课(七)

第六讲延时开关电路延时开关电路有两种,一种是延时关电路,比如有的楼道照明灯就是这种电路,我们只须将开关按一下,照明灯亮一会儿,就自动熄灭了;另一种是延时开电路,比如自动爆破,就需要经过一段时间电路自动接通,引燃炸药爆炸。一、预备知识 1.在延时开关电路里,我们将用到一个新的元件——按键开关。按键开关只有按下去开关才接通,一松手开关就会自动断开。按键开关种类有很多,我们在组装延时开关电路里用的是一种电话机上常用的按键开关,外观如图1。     

微封装功率MOSFET应用(三)——减小功率开关冲击电流措施

功率开关用在控制负载电路通、断时,若负载前端有大电容,由于开关的导通电阻极小,若电容器的等效串联电阻(ESR)较小,开关在接通瞬间,电源对电容器的充电电流很大、形成冲击电流。冲击电流超过MOSFET的极限脉冲漏极电流IDM(IDM比连续漏极电流ID大3～5倍)时,若不采取措施,有可能使MOSFET损坏。图1是这种情况的示意图。功率开关接在电源与负载之间。负载电路前有一个大电解电容Co。     

新型脉冲电源等效电路动态特性研究

研究电感储能的新型脉冲电源提高效能问题,采用脉冲电容储能型电源,制造复杂。采用开关控制,限制了发展,同时由于给出了脉冲电源的等效电路并导出电路对应的变系数微分方程,方程的解析求解较为复杂。为解决上述问题,建立了电感储能型等效电路的模型,进行仿真,结果明确了电路各元件参数对输出脉冲特性的影响,验证了计算结果的可靠性。研究电感储能型脉冲电源电路参数的取值对输出脉冲电压的特性有着较明显的控制效果,通过适当选择各元件参数的取值,可以获得较小脉冲电压脉宽的同时又有较高的电压幅度。仿真结果为新型脉冲电源系统设计过程中参数的选择提供了可靠的依据。     

浅析高压隔离开关的常见缺陷及处理方法

隔离开关的主要功能是当断路器断开电路后,由于隔离开关的断开,使有电与无电部分能得到明显的隔离,起辅助开关的作用。高压隔离开关是在无载情况下断开或接通高压线路的输电设备,以及对被检修的高压母线、断路器等电气设备与带电的高压线路进行电气隔离的设备本文阐述了高压隔离开关常见的缺陷,提出了处理方法。     

一种新型有源电力滤波器的优化控制

针对目前有源电力滤波器存在的体积大、工作频率高等问题,提出采用新型有源电力滤波器并实现其优化控制。与传统的单相有源电力滤波器相比,新型的有源电力滤波器所用功率开关元件少,电容容量小,不需直流侧储能元件,具有主电路结构简单、体积小、补偿效果好等优点。文中以电网电流的总谐波畸变最小作为控制目标,以滤波器主电路功率开关的开关时间作为优化变量,确定滤波电流补偿分量的数学模型,利用遗传算法进行优化控制,从而确定最优开关时间,然后利用Maflab／Simulink软件包,对带有整流负载的单相电网系统进行建模、仿真分析,仿真结果证明了所提方案正确性,控制效果良好。     

防止蓄电池损坏的欠压保护电路

蓄电池在电压过低时应及时切断负载,以免过放电损坏蓄电池。这个电路可起这种保护作用。二极管D_1用来防止蓄电池极性接反时损坏电路中的器件。在启动开关S_1未接通之时,保护电路和负载均无电流通过。一旦按钮开关S_1被揿下,继电器J通电使触点闭合,并使Q_1和Q_2导通。这时即使S_1释放,保护电路和负载也处于工作状态。     

半导体激光器驱动电路的计算机仿真分析

直接调制的大电流窄脉宽驱动电源是半导体激光器获得高峰值功率输出的重要保证.为了研究半导体激光器驱动电路,提高系统的精度和抗干扰能力,采用计算机仿真的方法分析了半导体激光器脉冲电源基本电路和雪崩晶体管脉冲电源电路.通过仿真结果表明,脉冲电源中元件的寄生电感及串联电阻对激光器工作电流脉冲的波形影响很大.当奇生电感小时,放电电流波形的上升时间就短.可为设计半导体激光器驱动电路时,提供选取R、C、L的依据,并保证工作在欠阻尼的情况下,要获得最大的放电电流,储能电容器上的充电电压要高,使电路的串联电阻尽量要小.     

基于 ＦＮＯＶ￣ＭＰＰＴ 的多压电输入无整流桥的能量采集电路的研究

环境能量俘获中压电振动能量采集的接口电路设计已成为近几年研究的热点之一。串联同步开关电感S-SSHI(Series Synchronous Switch Harvesting on Inductor)接口电路作为一种常用的能量采集接口电路。只有当负载阻抗与压电元件(PZT)输出阻抗匹配时,才能获得最大能量转换效率。针对以上问题,本文提出了一种无分时开路电压法的最大功率跟踪Fractional Normal-Operation Voltage Maximum Power Point Tracking (FNOV-MPPT)控制电路用于S-SSHI接口电路的最大功率跟踪,与传统的分时开路电压法相比,无需断开PZT与负载端的连接,在S-SSHI接口电路正常工作期间进行最大功率跟踪,其效率最高可达97%。采用的极值检测电路只用四个三极管和一个检测电容,降低了电路功耗。同时本文所提出的电路具有很好的扩展性,可以通过一个FNOV-MPPT控制电路的方式进行多PZT能量同时采集。     

Research on simulation of ship electric propulsion system with flywheel energy storage system

Flywheel energy storage has been widely used to improve the ground electric power quality. This paper designed a flywheel energy storage device to improve ship electric propulsion system power grid quality. The practical mathematical models of flywheel energy storage and ship electric propulsion system were established. Simulation research on the effect of ship electric propulsion system power quality, made by flywheel energy storage, was completed by using the software Matlab/simulink. We have done a lot of simulation experiments on sudden load of ship integrated electric propulsion system, one system is with flywheel energy storage, another one is not with. Comparing with these simulation results, we can see that the flywheel energy storage designed in this paper has improved ship electric propulsion system network power quality as well as increases the reliability of the ship power grid. The conclusions can provide a theoretical guidance for the design of flywheel energy storage applied in ship integrated electric propulsion system.     

基于能量捕获和混合储能的微观网络能量最优分配算法

随着纳米技术和无线网络技术的快速发展,单个节点(设备)的微小尺寸和有限能量严重地限制了微观无线网络的应用。因此,在传统宏观网络节点储能结构单一和能量捕获技术不稳定的基础上,利用超级电容的快速充放电特性,提出了一种基于超级电容和电池的混合储能结构。在此混合储能结构的基础上,根据点对点的双工信道模型和能量传输损耗特性,建立了面向能量捕获的网络吞吐量模型和节点能量分配解析模型,并提出了相应的能量最优分配算法,实现了节点吞吐量的最大化。该算法根据节点捕获能量的时域分布,优化分配超级电容与电池的能量值;同时,采用最优传输功率与传输时间进行数据传输。实验结果表明,所提混合储能结构和能量分配算法能有效地提高节点的吞吐量。     

多虚拟电厂接入的主动配电系统优化经济调度

在市场环境下,为促进含随机性可再生能源的消纳同时协调各经济主体矛盾并挖掘各主体价值和经济效益,本文提出一种基于分析目标级联理论的主动配网调度优化模型,以配网与虚拟电厂存在电能交互为建模背景。考虑虚拟电厂组成的多样性,设置风储型虚拟电厂以及含冷热电系统型虚拟电厂,各虚拟电厂可以分别与配网进行电能交互,各经济主体根据自身组成优化内部变量以及交互功率,通过分析目标级联法与其他主体协调交互功率实现分布式求解。最后通过IEEE33节点配电系统的算例仿真表明,调度结果能较好的反应主体经济性,得出风储型虚拟电厂有利于提高风电的消纳量,冷热电联供型虚拟电厂可以实现综合能源经济管理,分析目标级联法用于本文所提的模型背景是有效的。     

存储局域网及其交换结构研究

对传统的依赖于服务器的存储方式进行了讨论，分析了其缺陷，在此基础上论述了存储局城网技术，并详细讨论了在采用光纤通道的存储局域网中主要使用的两种交换结构：虫洞交换和虚拟通路交换．随后介绍了两种交换结构的区别，给出了与传统存储方式相比，存储局域网的优点。     

Green Approach for Joint Management of Geo-Distributed Data Centers and Interconnection Networks

Every time an Internet user downloads a video, shares a picture, or sends an email, his/her device addresses a data center and often several of them. These complex systems feed the web and all Internet applications with their computing power and information storage, but they are very energy hungry. The energy consumed by Information and Communication Technology (ICT) infrastructures is currently more than 4% of the worldwide consumption and it is expected to double in the next few years. Data centers and communication networks are responsible for a large portion of the ICT energy consumption and this has stimulated in the last years a research effort to reduce or mitigate their environmental impact. Most of the approaches proposed tackle the problem by separately optimizing the power consumption of the servers in data centers and of the network. However, the Cloud computing infrastructure of most providers, which includes traditional telcos that are extending their offer, is rapidly evolving toward geographically distributed data centers strongly integrated with the network interconnecting them. Distributed data centers do not only bring services closer to users with better quality, but also provide opportunities to improve energy efficiency exploiting the variation of prices in different time zones, the locally generated green energy, and the storage systems that are becoming popular in energy networks. In this paper, we propose an energy aware joint management framework for geo-distributed data centers and their interconnection network. The model is based on virtual machine migration and formulated using mixed integer linear programming. It can be solved using state-of-the art solvers such as CPLEX in reasonable time. The proposed approach covers various aspects of Cloud computing systems. Alongside, it jointly manages the use of green and brown energies using energy storage technologies. The obtained results show that significant energy cost savings can be achieved compared to a baseline strategy, in which data centers do not collaborate to reduce energy and do not use the power coming from renewable resources.     

一种磁电自供电无线传感器电源管理电路研究

针对GMM/PZT磁电复合单元将电磁波能量转化为电能时,其输出电能不足以直接驱动无线传感器的问题,设计了基于开关电容网络的电源管理电路,对其充放电特性进行了理论与实验分析。结果表明,该电路可以对电路中储能电容充电积累能量,当能量积累到一定程度,电容瞬间放电为无线传感器工作供电。     

微网内储能单元的建模及协调控制

通过仿真建模的方式研究电池类储能单元与电网负荷交互的特性以及储能单元对实现微电网电量自平衡的重要作用。根据锂离子电池特性,从电化学角度分析建立等效电路模型,通过对实际3．4V／3Ah锂离子电池充放电曲线的分析计算来确定电池模型参数,模型仿真曲线与实际充放电曲线拟合程度高。进一步构建储能单元模型,模拟仿真微电网中负载发生突变的情况,可以观察到储能单元对于微电网能量自平衡的贡献。     

A power-saving data storage scheme for wireless sensor networks

In wireless sensor network (WSN), sensors are small, inexpensive, and computable. However, they are limited in power, memory, and computational capacities. A large number of tiny sensors are usually deployed randomly to monitor one or more phenomena to collect and process the sensed data, and to send the data back to the sink. Many literatures focus on developing power-saving protocols. In addition, many papers present data storage schemes but they do not take power saving into consideration. Hence, these data storage schemes cannot perform well based on power-saving protocols. Therefore, it is very critical to propose a data storage scheme to support power-saving mechanism. In this paper, we propose a power-saving data storage scheme for WSN. Our scheme adopts grid-based architecture, in which each grid guarantees that two sensors will stay in active mode while the others stay in sleep mode to save energy. Simulation results show that our power-saving data storage scheme can reduce energy consumption.     

基于RS纠删码的无线传感器网络信息分发协议性能评价

无线传感器网络中,传感器节点的能量、存储和计算能力有限,且无线传感器网络具有数据链路不对称、拓扑易变化等特点,设计节能可靠的网络协议是困难的。设计良好的网络协议不仅能降低网络的负载,还有助于节省传感器节点的能量,从而延长网络的生存周期。在无线传感器网络操作系统TinyOS平台上实现了基于RS纠删码的信息分发协议,并理论分析了在单跳情况下的协议性能,最后在仿真环境TOSSIM上模拟比较了在多跳、多路径情况下该信息分发协议和洪泛分发协议的性能。模拟仿真表明,提出的基于RS纠删码的信息分发协议明显减少了发送方发送数据包的数量,同时提高了节点的报文接收率,从而达到了降低网络能耗的目的。     

无线传感器网络节能探索与研究

无线传感器节点往往由电池供电,由于电池只能存储有限的能量,使得无线传感器网络注定寿命很短,因此,最大限度延长传感器设备的使用寿命是一个重要的研究方向和课题.在本次无线传感器网络节能探索研究中,分析了能量收集与管理策略,能量收集主要收集环境能源,如太阳能,通过超级电容实现能量的存储.能量管理主要通过能量预算让传感器节点处...