计及电压质量的风电场无功主动控制策略研究

随着风力发电的快速发展,电网中风电场并网的数量及规模越来越大,但风电场功率的波动特性会给电网的电压质量及无功控制造成很大的不利影响。为保证风电并网后的电压质量在合格范围内,在对风电机组有功出力特性及无功调节特性分析的基础上,提出了一种新的风电场无功主动分层控制策略。第一层根据负荷预测和风电功率预测获得下一时段的无功功率...     

一种基于图的电力数据可视分析方法

将可视化分析技术应用于电力系统可以有效地解决由电力系统发展带来的海量电 力数据分析及显示等问题,从而辅助电力部门进行决策。针对城市电力数据,提出了一种基于 图的电力数据可视分析方法。首先对城市供电数据进行预处理;然后对城市供电网络进行建模; 最后根据可视化原则针对城市供电网络中的多种电力数据设计不同的可视化方法进行可视化与 分析。根据合肥市某区域的电力数据的案例分析,表明该方法可以有效地反映某一区域的电力 系统运行状态和电力客户分布情况。     

谐振式无线电能传输电源方案设计分析

在无线电能传输系统中,需要通过提高交流电源的频率来提高系统的传输效率。目前国内外对无线电能传输系统的研究都是直接将经典E类功率放大器或者逆变电路作为其高频电源,研究整个系统的传输特性,而对不同场合下如何选择高频电源没有系统分析。针对这一点,在结合几种高频电源以及开关器件的特点下,总结出无线电能传输系统在不同功率场合下的最佳电源选择。此外,提出将IGBT作为E类功率放大器的开关器件用于几百瓦左右的中等功率场合,以及将三相式E类功率放大器用于小功率的多负载输出场合。仿真分析了每种电源的特点和适用范围,为研究无线电能传输电源提供了系统的理论参考。     

Virtual machine power measuring technique with bounded error in cloud environments

In virtualized datacenters, accurately measuring the power consumption of virtual machines (VMs) is the prerequisite to achieve the goal of fine-grained power management. However, existing VM power models can only provide power measurements with empirical accuracy and unbounded error. In this paper, we firstly formulize the co-relation between utilization and accuracy of power model, and compare two classes of VM power models; then we propose a novel VM power model which is based on a conception named relative performance monitoring counter (PMC); finally, based on the relative PMC power model, we propose a novel VM scheduling algorithm which uses the information of relative PMC to compensate the recursive power consumption. Theoretical analysis indicates that the proposed algorithm can provide bounded error when measuring per-VM power consumption. Extensive experiments are conducted by using various benchmarks on different platforms, and the results show that the error of per-VM power measurement can be significantly reduced. In addition, the proposed algorithm is effective to improve the power efficiency of a server when its virtualization ratio is high.     

Strategic bidding using reinforcement learning for load shedding in microgrids

A microgrid is a small-scale power system for providing reliable power supply to a small community. The goal of microgrid operation is to balance the amount of power supplied and the amount of power demanded. In the islanded operation mode of a microgrid, if power requirements are larger than the power generation, load shedding is used to solve the power balance problem. Load shedding restricts the use of power by consumers. In a distributed load-shedding approach, a control center allocates the power to power consumers through a bidding process. At that time, power consumers need bidding strategies to maximize their profits. We propose an optimal bidding strategy using a Q-learning algorithm. To evaluate the performance of the proposed bidding strategy, we implemented a microgrid operation system, and an experimental analysis was performed.     

Development of hybrid hydraulic–electric power units for field and service robots

Energetic autonomy of a hydraulic-based mobile robot requires a power source capable of both hydraulic and electrical power generation. The hydraulic power is used for locomotion, and the electric power is used for the control computer, sensors and other peripherals. In addition, the power source must be lightweight and quiet. This study presents several designs of internal combustion engine-based power units. Each power unit is evaluated with a Ragone plot which shows its performance over a wide range of operation times. Several hydraulic–electric power units (HEPUs) were built and successfully demonstrated on the Berkeley lower extremity exoskeleton (BLEEX). The best-performing design of the HEPUs, based upon the Ragone plot analysis, is described in detail. This HEPU produces constant pressure hydraulic power and constant voltage electric power. The pressure and voltage are controlled on board the power unit by a computer. A novel characteristic of this power unit is its cooling system in which hydraulic fluid is used to cool the engine cylinders. The prototype power unit weighs 27 kg and produces 2.3 kW (3.0 hp) hydraulic power at 6.9 MPa (1000 p.s.i.) and 220 W of electric power at 15 V DC.     

一种新型小功率臭氧发生器电源

介绍了小功率臭氧发生器电源的整体设计思路。电源为半桥逆变拓扑,采用功率MOSFET作为开关管器件,针对小功率使用领域使用电流互感器电路驱动MOSFET。提出了一种结构简单的控制电路,成功应用于臭氧发生电源中,获得了实验数据和波形。该电源结构简单,经济实用,具有很强的实用价值。     

电力需求侧管理与错峰用电分析浅谈

结合当前国内用电形势和供电企业具体的业务特点,以及电网建设的发展趋势,阐述电力需求管理与用户行为引导的关系,以及供电企业如何进行客户用电行为分析,制定和优化电力需求侧错峰用电方案,实现错峰用电的精细化管理。通过已知历史和未知预测等各种复杂环境进行分析,根据供电企业的业务错峰方案所需的条件及流程,构建错峰用电方案的算法模型,并以此为基础设计出有效支撑供电企业业务开展的电力需求侧错峰分析报告以辅助企业决策提供支持。     

中小尺寸液晶屏图形显示控制芯片的低功耗设计

在VLSI设计中，低功耗的要求已经变得越来越重要。低功耗设计可以在不同的设计层次考虑．采用低功耗技术的层次越高，对功耗的改善越显著。本文针对一款中小尺寸液晶屏图形显示控制芯片的设计，提出了一种有效的低功耗设计方案。通过功耗分析比较表明．该设计方案极大的改善了这款芯片的功耗特性。     

面向电网智能管控的电力信息系统研究

随着电力信息化的不断发展,对于电网智能管控的研究逐渐被人们重视起来,并且已经上升到了国家建设层面。为促使电力供应更加稳定和合理化,本文提出了一种面向电网智能化建设的电力物联网体系,该体系基于基础物联网结构,从电力的输送、变压、分配、使用不同阶段出发,规避了原有物联网和电力物联网在功能和支撑技术上的差异。并基于电力物联网应用框架进行系统构建,该体系以物联网采集数量为基础,结合云计算,有利于实现数据统一处理并分析、电力资源统一调配。最终形成了一套面向电网智能管控的电力信息系统,将设备远程监控、电能质量监测、电力设备监测、实时故障处理、电力资产管理等功能集成于一体,有利于实现电力管控智能化,提高电网企业效率。     

电力系统中功率因数提高的方法和仿真

对于众多供电企业来说,用户用电功率因数的高低,直接关系到电网中的电能损耗和功率损耗,关系到供电线路的电压波动和电压损失,而且关系到电能的节约和供电的质量。为此,如何提高配电网功率因数,已成为众多供电企业的一个重要课题。首先提出了电力系统中功率因数低对电网的所带来的影响及提高功率因数的意义,然后再给出了具体提高功率因数的方法,并在此基础上设定了一定参数进行了功率因数提高的仿真。从而从理论上解决了提高功率因数的基本办法,符合了众多供电企业功率因数的要求。     

Managing power constraints in a single-core scenario through power tokens

Current microprocessors face constant thermal and power-related problems during their everyday use, usually solved by applying a power budget to the processor/core. Dynamic voltage and frequency scaling (DVFS) has been an effective technique that allowed microprocessors to match a predefined power budget. However, the continuous increase of leakage power due to technology scaling along with low resolution of DVFS makes it less attractive as a technique to match a predefined power budget as technology goes to deep-submicron. In this paper, we propose the use of microarchitectural techniques to accurately match a power constraint while maximizing the energy-efficiency of the processor. We will predict the processor power dissipation at cycle level (power token throttling) or at a basic block level (basic block level mechanism), using the dissipated power translated into tokens to select between different power-saving microarchitectural techniques. We also introduce a two-level approach in which DVFS acts as a coarse-grain technique to lower the average power dissipation towards the power budget, while microarchitectural techniques focus on removing the numerous power spikes. Experimental results show that the use of power-saving microarchitectural techniques in conjunction with DVFS is up to six times more precise, in terms of total energy consumed over the power budget, than only using DVFS to match a predefined power budget.     

基于ARIMA和神经网络的电能质量稳态指标预测

根据有功功率与五项电能质量稳态指标的相关性以及有功功率的数据特点,提出了一种对电能质量稳态指标的预测方法。该方法利用ARIMA时间序列算法对有功功率进行了预测,并根据有功功率与五项电能质量稳态指标的相关性建立神经网络预测模型对五项常规指标进行预测。通过分析预测结果与真实值的误差可得平均误差均在20%以内,该方法可以有效预测出电能质量指标序列的变化趋势,从而对电力系统的稳定性、安全性和经济性起到很好的作用。     

Wide Operational Range Processor Power Delivery Design for Both Super-Threshold Voltage and Near-Threshold Voltage Computing

The load power range of modern processors is greatly enlarged because many advanced power management techniques are employed, such as dynamic voltage frequency scaling, Turbo Boosting, and near-threshold voltage (NTV) technologies. However, because the efficiency of power delivery varies greatly with different load conditions, conventional power delivery designs cannot maintain high efficiency over the entire voltage spectrum, and the gained power saving may be offset by power loss in power delivery. We propose SuperRange, a wide operational range power delivery unit. SuperRange complements the power delivery capability of on-chip voltage regulator and off-chip voltage regulator. On top of SuperRange, we analyze its power conversion characteristics and propose a voltage regulator (VR) aware power management algorithm. Moreover, as more and more cores have been integrated on a singe chip, multiple SuperRange units can serve as basic building blocks to build, in a highly scalable way, more powerful power delivery subsystem with larger power capacity. Experimental results show SuperRange unit offers 1x and 1.3x higher power conversion efficiency (PCE) than other two conventional power delivery schemes at NTV region and exhibits an average 70% PCE over entire operational range. It also exhibits superior resilience to power-constrained systems.     

指令级密码处理器软件功耗建模与仿真

为了分析密码处理器软件的功耗,提高软件的抗能量攻击能力,提出了基于指令的处理器功耗建模仿真方法;详细阐述了模型建立、指令功耗求解算法以及指令功耗采集平台建立方法;在此基础上对一款密码专用处理器的AES加密算法软件功耗进行了仿真,对仿真结果和实际测量结果进行了比较分析,结果表明这种处理器功耗建模方法是有效的。     

基于微波无线传能的动态无线传能链路多目标规划问题

针对利用无线传能技术对移动无人单元进行动态传能的需求,选取微波无线传能作为传能方式.考虑在无线传能发射端与接收端之间设置中继传能节点的必要性,以及因无人单元连续移动所导致的无线传能链路的动态性,基于这类动态链路上采用不同中继传能节点部署方案所带来的在传能效率、系统成本等指标上的变化,构建一个包含发射端、接收端和可移动能量中继平台的动态无线传能链路多目标规划模型,在此基础上根据决策变量的特点,采用两种不同的进化算法对动态无线传能链路多目标规划模型进行双层迭代求解.求解结果验证了模型的有效性和微波能量中继传输对提高动态无线传能链路平均传能效率的作用.     

The monotonic increasing relationship between average powers of CMOS VLSI circuits with and without delay and its applications

The authors theoretically describe the monotonic increasing relationship between average powers of a CMOS VLSI circuit with and without delay. The power of an ideal circuit without delay, which can be fast computed, has been used as the evaluation criterion for the power of a practical circuit with delay, which needs more computing time, in such fields as fast estimation for the average power and the maximum power, and fast optimization for the low test power. The authors propose a novel simulation approach that uses delay-free power to compact a long input vector pair sequence into a short sequence and then, uses the compacted one to fast simulate the average (or maximum) power for a CMOS circuit. In comparison with the traditional simulation approach that uses an un-compacted input sequence to simulate the average (or maximum) power, experiment results demonstrate that in the field of fast estimation for the average power, the present approach can be 6-10 times faster without significant loss in accur     

基于遗传算法的最大开启电流估计

集成电路设计进入深亚微米阶段后，静态功耗成为低功耗设计中的一个瓶颈．电源门控法可以同时有效地降低动态功耗和静态功耗，是一项具有广阔应用前景的技术．电源门控电路的最大电流是由最大开启电流和最大的正常运行电流决定，它是电路设计的一个十分重要的参数，如何对它进行快速准确的估计已经成为一个新的问题．另外，冒险功耗是电路整体功耗中非常重要的组成部分，该文通过研究发现，在电路开启阶段同样存在冒险，同时消耗了大量的能量．文章考虑了组合电路的冒险现象，提出了一种基于遗传算法的最大开启电流的估计方法，对ISCAS85电路的实验结果表明，电源门控电路的开启最大功耗可能比正常情况下的最大功耗还要大．该文的方法具有较小的复杂性，可以仅用随机模拟的2．77％的时间，获得12．90％的最大开启电流值增量。     

因特网拓扑结构的幂律分析与建模研究

本文通过对因特网测量拓扑的幂律分布特征,包括frequency-degree幂律分布、degree-rank幂律分布与CCDF(d)-degree幂律分布的研究,发现因特网测量拓扑具有非常明显的frequency-degree幂律分布与degree-rank幂律分布规律。其中,frequency-degree幂律分布符合幂律指数为2.1406的分布规律,而degree-rank幂律分布则分为两部分,主体节点服从幂律指数为0.84639的分布,而度值最大的部分节点却符合幂律指数为0.29981的分布规律。在CCDF(d)-de-gree幂律分布研究中发现,Weibull分布要比幂律分布拟合效果更好。也就是说,对于本文Internet拓扑来说,其节点度的CCDF不一定符合幂律分布。根据frequency-degree幂律幂指数2.1406,本文在BA模型的基础上提出了改进的BA模型,确定网络增长连边概率方程中的ε为0.10812。     

A high level power model for Network-on-Chip (NoC) router

This paper presents a high level power estimation methodology for a Network-on-Chip (NoC) router, that is capable of providing cycle accurate power profile to enable power exploration at system level. Our power macro model is based on the number of flits passing through a router as the unit of abstraction. Experimental results show that our power macro model incurs less than 5% average absolute cycle error compared to gate level analysis. The high level power macro model allows network power to be readily incorporated into simulation infrastructures, providing a fast and cycle accurate power profile, to enable power optimization such as power-aware compiler, core mapping, and scheduling techniques for CMP. As a case study, we demonstrate the use of our model for evaluating the effect of different core mappings using SPLASH-2 benchmark showing the utility of our power macro model.