混合动力船舶超级电容制动能量回馈装置

针对混合动力船舶采用制动电阻吸收制动能量不可避免造成能量浪费的问题,借鉴直流推进系统,采用超级电容储能装置作为能量回馈装置,研究混合动力船舶在典型工况下的制动过程,并对超级电容在制动过程中的控制方法、控制效果进行分析.结果 表明:与制动电阻相比,超级电容制动能量回馈装置不仅能够提升直流母线电压的稳定性,还能有效吸收和储...     

基于混合储能的并网光伏发电系统功率控制研究

针对并网光伏发电系统输出功率的波动,提出利用混合储能系统对功率进行平抑.介绍了光伏最大功率跟踪和并网逆变的控制,为实现发电和并网功率的匹配,考虑蓄电池和超级电容器各自特性的优势,对混合储能系统提出了三级式功率分配策略;通过设计相应的控制方法和以功率分配单元的输出功率作为参考值,混合储能系统控制变换器进行合理充放电.混合储能系统不仅保证了并网功率按计划运行,而且稳定了直流母线电压、满足了随机负荷供电.通过仿真验证,三级式功率分配策略有效,控制方法可行.     

Application and research of flywheel energy storage system in electrified railway

本文提出了通过飞轮储能系统在线路负荷较重时对电网释能来降低变压器的出力,从而降低最大需量值或变压器容量;因为铁路负序最严重的时候为变压器处于峰值功率时,所以还可有效降低负序电流。由于飞轮储能装置是个储能体,同时具备储能和释能的双重功能,所以此系统还可吸收再利用机车制动时产生的制动电能,有效降低电度电费成本。本文先后介绍了系统整体结构、变流器系统、飞轮储能装置、测控单元,然后根据实际变电站参数和实测牵引负荷数据建立了该系统的仿真模型进行仿真,表明了所提出的飞轮储能系统应用于电气化铁路进行削峰填谷的正确性。     

基于超级电容储能的可变速驱动抵御扰动研究

提出基于超级电容储能的变频调速装置（ASD）抵御电网电能质量扰动的实用方案。超级电容模块接在直流母线上，在系统发生短时供电中断或电压暂降时，由超级电容储能供给负载有功支持。研制了具有抵御电能质量扰动的15kVA ASD实验室样机。数字仿真及物理实验验证了所提拓扑结构和控制策略消除电能质量扰动对ASD影响的正确性及有效性。     

System design and control strategy of the vehicles using hydrogen energy

This paper presented a system design review of fuel cell hybrid vehicle. Fuel supply, hydrogen storage, DC/DC converters, fuel cell system and fuel cell hybrid electric vehicle configurations were also reviewed. We explained the difference of fuel supply requirement between hydrogen vehicle and conventional vehicles. Three different types of hydrogen storage system for fuel supply are briefly introduced: high pressure, liquid storage and metal oxides storage. Considering of the potential risk of explosion, a security hydrogen storage system is designed to restrict gas pressure in the safe range. Due to the poor dynamic performance of fuel cells, DC/DC converters were added in hybrid vehicle system to improve response to the changes of power demand. Requirements that in order to select a suitable DC/DC converter for fuel-cell vehicles design were listed. We also discussed three different configurations of fuel-cell hybrid vehicles: “FC + B”, “FC + C”, and “FC + B + C”, describing both disadvantages and advantages. “FC + B + C” structure has a better performance among three structures because it could provide or absorb peak current during acceleration and emergency braking. Finally, the energy management strategies of fuel cell and were proposed and the automotive energy power requirement of an application example was calculated.     

Unified power quality conditioner based on a three-level NPC inverter using fuzzy control techniques for all voltage disturbances compensation

This paper presents a novel and efficient control scheme for unified power quality conditioner (UPQC) based on three-level neutral point clamped (NPC) inverter using fuzzy logic techniques. The proposed UPQC is capable of mitigating source current harmonics and compensate all voltage disturbances such as voltage sags, swells, unbalances and harmonics. It is designed by the integration of series and shunt active filters (AFs) sharing a common DC bus capacitor. The DC voltage is maintained constant using proportional integral voltage controller. The synchronous reference frame (SRF) theory is used to get the reference signals for shunt active power filters (APFs) and the power reactive theory (p-q theory) for series APFs. The shunt and series APF reference signals derived from the control algorithm and sensed signals are injected in two controllers to generate switching signals. To improve the UPQC capability, fuzzy logic techniques are introduced to control the series APF. The performances of the proposed UPQC system are evaluated in terms of power factor correction, mitigation of voltage or current harmonics and all other voltage disturbances compensation using Matlab-Simulink software and SimPowerSystem toolbox. The simulation results illustrate the performance of the proposed UPQC at the common connection point of the nonlinear load to improve the power energy quality.     

基于低压配电网无功负序不平衡现象的节能降损解决方案

低压配电网中普遍存在的三相不平衡现象将导致系统中出现负序电流,负序电流会在电网中产生损耗,并影响变压器及电动机的正常运行。为消除负序电流,达到节能降损的目的．可利用双向晶闸管控制电抗器、电容器并配合12脉动技术,实现低压配电网三相平衡;详细介绍三相平衡补偿原理,并在实验室搭建了试验模型,分析了得到的波形及数据,结果表明,12脉动技术降低了晶闸管向系统中注入的谐波,在无需滤波器的情况下,便能符合国家标准,节省了投资成本。     

Compensation of network voltage unbalance using doubly fed induction generator-based wind farms

A control strategy for compensating AC network voltage unbalance using doubly fed induction generator (DFIG)-based wind farms is presented. A complete DFIG dynamic model containing both the rotor and grid side converters is used to accurately describe the average and ripple components of active/reactive power, electromagnetic torque and DC bus voltage, under unbalanced conditions. The principle of using DFIG systems to compensate grid voltage unbalance by injecting negative sequence current into the AC system is described. The injected negative sequence current can be provided by either the grid side or the rotor side converters. Various methods for coordinating these two converters are discussed and their respective impacts on power and torque oscillations are described. The validity of the proposed control strategy is demonstrated by simulations on a 30 MW DFIG-based wind farm using Matlab/Simulink during 2 and 4% voltage unbalances. The proposed compensation strategy can not only ensure reliable operation of the wind generators by restricting torque, DC link voltage and power oscillations, but also enable DFIG-based wind farms to contribute to rebalancing the connected network.     

储能技术在中小型风力发电系统中的应用

讨论了储能技术的分类及应用范围,并对中小型风力发电系统的结构及其系统中储能的作用进行了阐述。同时分析了碳纳米管超级电容器储能、氢储能、超级电容器和蓄电池混合储能三种很有前途储能技术在中小型风力发电系统中的应用。     

车辆制动能量回收再利用技术研究

阐述了再生制动的原理、应用,以及再生制动技术实现装置的三个主要部分,通过对能量转换装置和储存装置的分析,指出电储能再生制动技术是未来车辆所需的一项关键性实用技术。在对再生制动控制策略的国内外研究进展总结分析的基础上,提出了再生制动技术实现中的技术难题,指出独立附加型的再生制动装置和电磁制动是未来的发展趋势。     

Integrated control strategy of vehicle supercapacitor energy storage system based on MMC

针对单辆城轨列车在起动、制动过程中对牵引网电压造成冲击从而引起网压不稳定的问题,提出一种基于MMC的车载超级电容储能系统（车载MMC-SCESS）,该系统以MMC拓扑结构作为主电路,通过将超级电容储能单元分散接入MMC子模块中,提高系统的控制灵活性与容错性;其次以车载MMC-SCESS的整体结构为研究对象,详细分析其a相桥臂电路工作原理,总结出每个储能子模块的一般工作模式。针对该储能系统主电路结构,提出采用综合控制策略,通过控制超级电容储能单元的充放电状态来实现能量在城轨列车、直流牵引网、超级电容储能系统三者之间流动。最后在Matlab/Simulink中搭建三相五电平车载MMC-SCESS仿真模型,仿真波形验证了储能系统控制策略的可行性。     

Design and implementation of an energy efficient power conditioner for fuel cell generation system

The energy use of the world grows continuously and the development of a clean distributed power generation becomes environmentally important. Fuel cells are one such integral part of Renewable Energy Sources based clean energy supply; that they operate with hydrogen as fuel and water with heat as process waste. Due to the electrochemical reaction, fuel cell has the power quality of delivering low voltage with high current capability. Here an attempt is made to develop a power conditioner with a series of conversion to get a 220 V sinusoidal AC, 50 Hz single phase voltage of low distortion and fast dynamic regulation to cater load variations. A novel Polyphase Boost DC-to-DC switching converter based on parallel connection of 8 identical converters with current mode control is devised to have minimum reflected ripple current and voltage injected to fuel cell input. A full bridge converter with high frequency transformer isolation, step-up the DC voltage level from the low voltage fuel cell along with poly phase boost converter, deliver required DC to the PWM inverter, which generate AC utility power output. Recent trend of Ultra-capacitor based transient energy storage and retrieval system, to cater for the sluggish behavior of fuel cell, for load transients is incorporated. DSP and FPGA based digital real time controllers are used to realize the gating of MOSFETs and IGBTs used in the power conditioner. A 1 kW power conditioner is developed for a PAFC fuel cell system with 12 V DC nominal and their performance evaluations are satisfactory.     

基于SOC的混合储能风电功率平抑方法

近年来风电等可再生能源的装机容量越来越大,鉴于风电的输出功率随机性特别强且波动性十分大,在混合储能风电平抑系统的基础上引进滞环控制,提出了一种基于超级电容端电压的能量管理方法。该方法通过在低通滤波算法中引进滞环控制,可将风电功率的波动幅度严格控制在滞环宽度之内;同时根据监控超级电容端电压判断电池的荷电状态(SOC),防止超级电容频繁过度地充电和放电,有利于延长储能装置的工作寿命,最后通过仿真试验,验证了该方法的有效性。     

A novel predictive power flow control strategy for hydrogen city rail train

Hydrogen-based vehicular traction has already reached a mature technological level and can replace the more polluting diesel engines. The adoption of this technology can also alleviate the carbon footprint issue of the rail trains running on non-electrified lines.This study presents a model and a numerical performance analysis of an electric hybrid train in an urban context. The train uses hydrogen as fuel and operates over non-electrified lines with zero local emission.The electric traction motors of the train are fed by a hybrid power unit consisting of several hydrogen fuel cell stacks operating independently in on/off mode and a set of flywheel energy storage devices.Each component of the power train is modeled separately and its operating limits are chosen on the base of technical literature.An innovative predictive logic to manage power flows is defined and proposed with the aim to minimize the fuel consumption. Furthermore, this approach uses a regenerative electrical braking and eliminates dissipative devices, like rheostats, which are commonly utilized onboard electric trains.This predictive approach is based on the optimal management of the power unit components according to the advanced knowledge of the data of the rail vehicle, the characteristics of path, drive cycle and payload for an established route.The fuel cell stacks operate accordingly to the average traction power requirement in each railway line section, whereas the flywheel energy storage system manages the dynamic power.A parametric model of the system and a respective software tool have been developed; this implementation, that incorporates many tunable parameters of the train and rail path, is able to simulate the rail train operating on a specific railway path by implementing the novel control strategy.An existing single track non-electrified line, designed again for urban service, has been selected as a case study to evaluate the performance of the proposed system.The specific fuel consumptions obtained with the novel control strategy and with a single fuel cell system operating at constant power are compared under the same operating conditions.The results highlight that significant fuel savings can be achieved.     

纯电动船复合储能系统的设计与优化

针对纯电动船中的动力电池组易受瞬态大电流的冲击、使用寿命短等问题,提出以磷酸铁锂电池和超级电容为核心的复合储能系统方案,进行理论分析,并采用DC/DC变换器以更好地发挥超级电容性能。采用带精英策略的非支配排序遗传算法进行多目标优化选型,结合能量管理策略,实现储能系统的优化配置。仿真结果表明,得到的选型方案结合以模糊控制为核心的能量管理策略能够很好地应对波动性负载。     

The study of control strategy for urban mass transit based on flywheel energy storage system

针对城市轨道交通列车运行密度高,起制动功率大的特点,采用飞轮型再生制动能量回收装置可有效降低直流牵引网压波动,降低牵引能耗。由于该装置采用基于直流牵引网母线电压高低进行充放电的控制策略,在实际运行工况中可能存在无法准确识别再生能或储能设备SOC值无法自动调整导致无法再响应牵引网压波动的情况,本文提出空载网压识别和SOC自适应控制策略进行解决,通过轨道交通试验平台的试验验证,得出该控制策略的有效性。     

Analysis and comparative study of pulsating current of fuel cells by inverter load with different power converter topologies

Fuel cells are being increasingly used for stand alone and grid connected systems in wide range of applications due to their high efficiency and low emissions. Because of unregulated nature of fuel cell voltage a power conditioning unit, consisting of DC-DC converter and an inverter, is invariably used as an interface between the fuel cell and the load in a typical fuel cell system for ac applications. Major issues with the use of fuel cells for ac applications are the low frequency pulsating current propagation on to the fuel cell side and dynamic response to various loads during transient conditions. Low frequency pulsating currents are reported to affect reactant utilization, degrade the performance and life of fuel cells. These current ripples can be reduced by filters with passive elements having bulky inductor and capacitor in the dc-link between the fuel cell and the inverter but, it will add to the weight and cost. DC-DC converters of different configurations are being used in the power conditioning unit of fuel cell systems. These converters are operated at high frequencies and the filtering units of these converters have minimal effect on low frequency ripple. But, it is observed that different configurations of power conditioner with same filtering components perform differently for the low frequency current ripple of the inverter load by mitigating the power mismatch between load and source at the DC link. This paper investigates and compares the low frequency current ripple mitigation by cascaded converters with conventional push-pull and also with series connected converters in the power conditioning stage of fuel cell system for ac applications. Parameters such as peak switching currents, the percentage of peak to DC level of low frequency current ripple are analyzed using these conversion topologies in power conditioning unit. The analytical and simulation results related to the study are presented. Key results are verified with experimental work.     

Application of array 1 MW flywheel energy storage system in rail transit

本文根据城市轨道交通的运行特点和车辆参数提出了一种1 MW阵列式飞轮储能系统,用来吸收再利用机车制动时产生的制动电能。通过对比不同类型的再生制动能量回收方式,突出飞轮储能系统应用在城市轨道交通的必要性和先进性。文中通过对某些线路进行数据测试,根据现有单台飞轮储能装置进行阵列式组合,通过产品优化以及安全计算和工程实施预判,组装出容量为1 MW的阵列式飞轮储能系统,并证明了1 MW阵列式飞轮储能系统在城市轨道交通应用的正确性和可实施性。     

电气化铁路中SVC负序补偿应用技术研究

随着电气化铁路的迅速发展,电铁牵引负荷产生的负序分量及高次谐波,除对牵引供电系统造成危害外,还会造成电力系统负序及谐波污染^[1],因而,电铁的负序及谐波危害已成为制约我国电气化铁路发展的重要因素。结合电气化铁路给电网带来的影响,着重探讨电铁负序补偿中SVC的使用问题。根据国外一些发达国家如日本、澳大利亚等国成功将SVC技术应用在电气化铁路的无功和负序补偿案例以及国内SVC负序补偿应用实例,对SVC负序补偿原理及运行方式进行了研究分析,对SVC在电铁负序治理中的应用前景做了初步探讨,以期提高电力系统运行的经济效益和社会效益。     

超级电容器在微电网中的应用

随着可再生能源发电技术的发展,能够整合分布式电源的微电网是满足日益增长的电力需求、节省投资和提高能源利用效率的一种有效途径。储能系统作为微电网必要的能量缓冲环节,其作用越来越重要。概述了超级电容器的特征和性能,分析了超级电容器储能系统的结构和控制原理,并详细阐述了其在微电网中的应用。基于超级电容器的储能系统,不仅起到能量缓冲的作用,还能够提供短时供电、缓冲微电网中负荷波动、均衡微电源输出、改善微电网电能质量,并且对微电网的经济性能有重要作用。