超导储能装置在提高电力系统暂态稳定性中的应用

超导储能(superconducting magnetic energy storage,SMES)装置可以很好地改善电力系统暂态稳定性。文中基于PSS/E平台研究了储能装置改善电力系统暂态稳定性的作用,分析了储能装置在不同安装地点以及不同安装容量下对系统暂态稳定性的影响,并给出了效果对比分析,对储能装置实际应用具有一定的指导意义。最后,通过实际华东电网宁德-双龙通道的仿真分析,验证了储能装置在改善电力系统暂态稳定性,抑制系统振荡方面的效果。     

静电除尘器电源装置节能技术研究

通过开展静电除尘器电源装置机理的研究,对静电除尘器不同电源装置的减排和节电性能有了清晰的认识,提出了既减排效果好、又节电的节能电源;通过调研不同电源的应用情况,指出脉冲电源使用效果不佳的原因。根据烟尘比电阻特性不同提出了采用不同电源的组合方案。     

一种用于双凸极永磁发电机的电容储能型变换器

提出了一种用于双凸极永磁发电机(DSPMG)的电容储能型变换器(CERC)。通过分析DSPMG的电磁特性和发电原理,提出了一种针对CERC的控制策略。与传统的三相全桥整流电路(FBR)对比,在相同的负载条件下,采用CERC电路的DSPMG发电系统的输出功率有明显提升。仿真和实验均证实了所提出的拓扑和控制策略的正确性。     

Energy Saving Speed and Charge/Discharge Control of a Railway Vehicle with On-board Energy Storage by Means of an Optimization Model

The optimal operation of rail vehicle minimizing total energy consumption is discussed in this paper. In recent years, the energy storage devices have enough energy and power density to use in trains as on-board energy storage. The on-board storage can assist the acceleration/deceleration of the train and may decrease energy consumption. Many works on the application of the energy storage devices to trains were reported, however, they did not deal enough with the optimality of the control of the devices. The authors pointed out that the charging/discharging command and vehicle speed profile should be optimized together based on the optimality analysis. The authors have developed the mathematical model based on a general optimization technique, sequential quadratic programming. The proposed method can determine the optimal acceleration/deceleration and current commands at every sampling point under fixed conditions of transfer time and distance. Using the proposed method, simulations were implemented in some cases. The electric double layer capacitor (EDLC) is assumed as an energy storage device in our study, because of its high power density etc. The trend of optimal solutions such as values of control inputs and energy consumption is finally discussed. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

CPT及IRPT多场景电流分解对比及分析

以新能源为主体的新型电力系统发展对系统计量装置、功率变换设备等提出了新要求,迫切需要革新的功率理论指导上述设备的设计与控制,以适应不同电气系统结构。通过构建多种含不同源荷类型的三相电气系统场景,针对守恒功率理论（CPT）及瞬时无功功率理论（IRPT）,重点讨论二者在不同应用场景中电流分解的相似点及不同点。分析结果显示：IRPT仅在电压正弦条件下可以获得较好的电流分解结果,而基于CPT的电流分解,在正弦或非正弦等不同电压、负荷情况下均可较好地解释功率传输现象、分析负荷特性,其可作为有效的理论工具用于负荷特征识别、电费计量、滤波与补偿、功率变换器等领域中。     

电动挖掘机交流变频系统电能反馈制动装置

电动挖掘机交流变频调速系统一般采用简单的能耗制动,存在浪费电能、电阻发热严重,快速制动性能差等缺点。本文结合电动挖掘机的工作状况,拟研制开发交流变频调速系统电能反馈装置,反馈装置作为有源逆变单元,并联到变频器的直流侧,将挖掘机制动过程中产生的再生能量反馈到交流电网中。该装置既可以为矿山企业节约电能消耗,降低生产成本;又能提高电动挖掘机的工作性能,改善调速精度。这对提高矿山企业的经济效益和社会效益是非常重要的。     

面向电力传感器的环境能量收集技术发展趋势及面临的挑战

电力传感器作为能源互联网感知层的基本组成部分,其供电稳定性是广大从业者的关注重点.通过环境能量收集技术为传感器供电,可使传感器具有自供电特性以及长期免维护的优势,能量收集技术在电力传感领域的应用受到了越来越广泛关注.综述了环境能量收集技术在电力领域的应用现状以及温差、振动、风致振动等新型能量收集技术的特点.结合电力行业...     

电力电子并网装备等效惯量评估研究进展

高比例新能源依靠变流器等电力电子设备并网,削弱系统惯量特性的同时也丰富了系统惯量的来源。为明晰惯量评估在新型电力系统中的作用和潜力,评述了国内外电力电子并网装备等效惯量评估领域的研究进展,并提出探讨与展望。从能量来源的角度简要阐述等效惯量的内涵,根据功率扰动和频率量测2个要素,回顾惯量离线估计的研究历程。通过划分2种主流的研究思路,对电力电子并网装备及新能源电力系统的惯量在线评估研究成果进行梳理。最后尝试对未来新能源电力系统惯量评估领域需深入研究的方向提出展望。     

构建新型电力系统背景下输电网架加强投资决策模型

为实现“碳达峰”和“碳中和”目标,构建以新能源为主体的新型电力系统是我国能源电力领域未来一个阶段面临的重要工作和任务,单纯依靠传统的投资建设接入系统的方式不能有效解决大规模新能源发电并网给电力系统带来的问题。提出了一种含有柔性输电装置的输电网架长期投资决策模型,通过在现有输电网加装柔性输电装置,既可满足新能源发电并网的需求,又能够有效提高投资效率,极大提高了输电投资决策的灵活性。算例研究表明,在一个改进的IEEE-24节点测试系统中,通过分别考虑线路扩展和加装PS、SC设备的不同组合,形成了不同的输电网架加强投资方案。所提方法能够为决策提供良好的输电网架加强方案,在投资成本和缓解拥堵所节省的费用之间取得平衡。     

面向全局无功优化的变电站电压无功控制器的设计

通过对现有各种电压无功补偿装置的分析研究,针对它们的不足之处,提出了相应的解决方案,同时将混成自动电压控制理论应用到变电站电压无功综合控制装置的设计中,实现了电压无功的全局优化。     

A new electro‐static micro‐generator for energy harvesting from diaphragm muscle

In this paper, we propose a new energy scavenging system for powering bio‐implantable devices. Different available energy sources and micro‐generators are examined. The operation of electrostatic generators will be examined in detail, and their design issues are discussed. The proposed generator is analyzed, and a closed form formula is developed for the capacitor voltages. Also, an equation is obtained for the output power for the proposed circuit. It will be shown that the diaphragm muscle in conjunction with the electrostatic micro‐generator can be used to extract energy from human body. The diaphragm muscle has a continuous movement with a relatively fixed frequency. There is enough space around this muscle to place the micro‐generator. Using the proposed system, it will be shown that it is possible to produce 230 mW power in a 125 mm³ volume from the diaphragm muscle. Copyright © 2017 John Wiley & Sons, Ltd.     

Modeling and Management of Batteries and Ultracapacitors for Renewable Energy Support in Electric Power Systems–An Overview

Abstract—Energy storage devices and systems are playing a major role in all electrical systems from small electronics devices and automotive systems to the utility grid. The main objective of this article is to review energy storage devices, management, control, interface, and demonstrations for electrical power systems. Various types of energy storage systems are discussed, but the main focus is on batteries and ultracapacitors. Different types of batteries and their electrical models are explained. Three major types of ultracapcitors are also discussed. The battery management system and its functions, controls, and hardware are discussed. Various power electronics-based interface systems for battery and ultracapcitor charging and discharging are presented. Applications of energy storage systems for utility applications, including renewable firming, power shifting, and ancillary services, are discussed.     

Power Solar - The sun in your pocket

The concept of a free, renewable and inexhaustible supply of electricity harvested from the sun is an ideal scenario toward which many governments and green activists are striving. They possibly perceive it as large arrays of photovoltaic cells situated on buildings or harvested from acres of solar farms. According to the Energy Savings Trust, the fastest growth in energy usage stems not from gas-guzzling cars or expanding jet travel, but from consumer electronic devices, such as mobile phones and MP3 players. The emphasis the consumer electronics vendors are putting on longevity of battery life adds credibility to the component manufacturers' claims. Yet we have been here before with integration of fuel cells into portable devices three years ago. But the integration of solar power is more likely to occur as the technology has overcome a significant barrier which fuel cells so far have not - a smaller footprint.     

基于综合储能设备的工业园区联络线功率实时MPC控制方法

工业园区微电网基础设施完善、储能设备众多，具有参与日前调峰、日内实时跟踪控制的潜力。工业园区内可能存在多个企业厂房，生产设备的种类有所差异，通过调整燃机出力实时控制联络线功率的传统控制方式，在不同的考核方案下难以兼顾各利益主体间的关系。因此从园区角度，利用园区内可支配的储能设备实行日内实时控制，能够有效协调各方经济利益，获得良好的控制效果。文章建立了储气、储冷、储电等多种储能设备的数学模型和房间热模型，为应对由于光伏、风电等清洁能源日前预测误差所产生的联络线功率波动，同时确保多种储能设备满足运行约束和冷、热、电、气负荷能量平衡约束，提出了一种基于模型预测控制（model predictive control，MPC）的日内滚动优化校正策略，在日前经济调度结果的基础上，通过调整储能设备的运行功率消除微电网中不确定因素的影响，以确保实现对日前调度结果的跟踪。以南方某蓄电池生产工业园区为例，通过算例分析验证了所提优化模型及算法的有效性。     

Sustainable micro-power circuit for piezoelectric energy harvesting tile

Piezoelectric energy harvesting tiles are used for converting the power of pedestrian footsteps in to electricity and can be used at the micro- and milli-watt level for storage and powering electronics devices. This paper effectively combines the systems and techniques for developing a sustainable circuit with the self-starting and self-power functions to efficiently store energy and drive low power consumption electronic devices from the piezoelectric energy harvester tile. The main part of the system is 80% efficient impedance matching converter with the self-starting and battery-less operation. The presented circuit has an overall efficiency of 63% and can power a wireless sensor node to transmit the information wirelessly.     

能量约束下电力电子并网装备的最优频率控制

大规模新能源并网导致现代电力系统的旋转惯量相对减少,频率动态特性变差。为支撑系统频率,通常要求新能源发电装备具备一定的惯量模拟或一次调频等附加控制功能,但目前在新能源的最优频率支撑方面研究较少。文中以最优控制为切入点,初步探讨了当参与调频的新能源存在能量约束时,作为并网接口的电力电子装备的最优功率支撑轨迹以及近似的最优控制结构。首先,从理论上推导并给出了多机系统的频率共模分量。该共模分量主导了电网的频率跌落特性。然后,基于高斯伪谱法研究了能量约束下电力电子装备在系统频率跌落时的最优支撑轨迹。最后,探索了电力电子并网装备支撑电网频率的最优反馈控制结构,指出虚拟惯量控制加下垂控制近似于最优的控制结构,且在可调用的能量较小时单独使用虚拟惯量控制优于下垂控制。仿真验证了理论分析和所讨论的频率最优控制结构的合理性。     

A Unified Approach to the Sizing and Control of Energy Storage Systems

Grid operation and planning challenges arising out of large-scale integration of renewable power can to a large extent be solved by the use of energy storage systems (ESSs). The type and size of storage to be used may be decided by the amount of fluctuating power the storage charges or discharges to attain its objective. Storage systems can be used as single devices or as hybrid systems where two or more devices complement the working of each other. The objective of this paper is to find an accurate power and energy sizing methodology for storage devices working in a single or hybrid arrangement such that the power fed to the grid from a wind turbine generator is regulated to a constant value. A strategy for sizing of a hybrid ESS is proposed by choosing the long-term storage to be a battery energy system and the short-term device to be a flywheel and using frequency analysis techniques. In the case of flywheel energy storage system, the inertia and the gain of an integral controller applied to an induction-machine-based flywheel are obtained. The simulations are done in MATLAB.     

考虑运行维护需求的海上风能与波浪能联合发电非同期规划

随着海上风电的规模化发展,海洋多能综合利用被广泛关注.在双碳战略背景下,探索在海上风电场内增设波浪能装置的可行性意义重大.提出一种考虑运行维护需求的海上风能与波浪能联合发电的非同期规划模型与优化方法.考虑海上风电场停机检修的用电需求,在现有海上风电场内增设波浪能发电装置;分析海上风机位置、运行维护及船只靠泊防撞等工程需求,优化波浪能装置布局.评估海上风能与波浪能的联合布置方案,最终得到综合考虑经济性、可靠性的优化方法.算例研究结果表明,采用联合发电的规划模型与优化方法可在保证联合发电可靠性的同时,有效提升联合发电经济效益及风机运行维护的便利性.     

风储联合运行经济调度模型研究

介绍了风电场中储能装置的相关控制策略;然后,基于传统的经济调度模型上,引入储能装置来平抑风电功率的波动性,并计及备用成本,从而建立了风电场中含储能装置的经济调度模型,重点分析了储能装置的引入和储能装置不同容量及不同最大充放电功率对经济调度的影响;最后,通过实际算例分析验证了该模型的有效性。     

A Micropower Electrocardiogram Amplifier

We introduce an electrocardiogram (EKG) preamplifier with a power consumption of 2.8 muW, 8.1 muV_rms input-referred noise, and a common-mode rejection ratio of 90 dB. Compared to previously reported work, this amplifier represents a significant reduction in power with little compromise in signal quality. The improvement in performance may be attributed to many optimizations throughout the design including the use of subthreshold transistor operation to improve noise efficiency, gain-setting capacitors versus resistors, half-rail operation wherever possible, optimal power allocations among amplifier blocks, and the sizing of devices to improve matching and reduce noise. We envision that the micropower amplifier can be used as part of a wireless EKG monitoring system powered by rectified radio-frequency energy or other forms of energy harvesting like body vibration and body heat.