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。     

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.     

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。     

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。     

Energy storage for urban rail transportation

城市轨道交通车辆再生制动产生大量再生电能,引入储能系统回收再生电能并进行循环利用,是未来建设节能型社会的要求与发展方向.本文针对城市轨道交通系统中的储能系统,首先,介绍了飞轮,超级电容,锂电池等储能系统目前国内外的应用情况;其次,比较了三者的性能和经济性,提出了超级电容-锂电池结合的经济性储能模式;最后,介绍了几种常见的储能装置控制策略,并结合近期储能系统的研究进展,指出了未来储能系统关键技术及其发展方向.     

Peak power bi-directional transfer from high speed flywheel toelectrical regulated bus voltage system: a practical proposal forvehicular technology

This paper provides a design outline and implementation procedure for a secondary energy storage unit (SESU) that can be used to meet the peak energy requirements of an electric vehicle during both acceleration and regenerative braking. The life cycle of the electric vehicle's batteries can be extended considerably by supplying peak energy requirements from a secondary source. A simulation study was conducted to determine the peak power and energy requirements over the SAE recommended electric vehicle test procedure. A scaled prototype SESU was built using flywheel energy storage, and tests were performed to determine the energy transfer capabilities of a flywheel coupled high speed permanent magnet synchronous machine through the proposed system's energy storage tank. Results are presented that indicate the necessity of the energy storage tank. An evaluation of the proposed system is also included which indicates the practicality of the system when compared to conventional regenerative control techniques     

飞轮储能技术研究五十年评述CSCD

本文回顾了飞轮储能技术研发50年的历程,分析了飞轮储能技术特点、应用领域以及关键技术问题。飞轮储能具有功率密度高、循环寿命长、响应迅速、能量可观性好以及环境友好的优点。当前,研制的飞轮储能系统单体能量为0.5~130 kW·h,功率为0.3~3000 kW。重点关注了飞轮用低成本高比强度新材料、高温超导磁悬浮技术。飞轮储能在电能质量调控、不间断过渡电源以及电网调频领域实现了商业化应用,在车辆混合动力领域的示范应用中实现节能20%~30%,处于产业应用的临界点。针对电网规模大功率、高能量储能需求,发展趋势是由数十千瓦时以下发展到百千瓦时,并通过阵列化组装成10~100 MW储能系统,放电时间可拓展到1 h。     

Flywheel array energy storage system

飞轮储能系统将能量储存在高速旋转的飞轮转子中,具有高功率密度,无环境污染,使用寿命长,运行温度范围广,充放电次数无限制等优点,已获得了广泛的应用.将多台模块化的飞轮储能单元并联起来组成飞轮阵列储能系统,是获得大容量,高功率储能的解决方案.文章首先论述了飞轮阵列储能系统的国内外发展现状与要解决的关键问题, 然后详细给出了飞轮阵列储能系统的设计方法,并联拓扑结构与控制策略.随着飞轮储能单元并联技术的逐渐成熟,飞轮阵列储能系统应用领域将逐步扩展到电力系统调频,间歇式可再生能源发电等领域,并将在提高电网对可再生能源的接纳能力等方面发挥重要作用.     

Flywheel energy storage systems for a 1.5 MW wind generator applications

飞轮储能在电网级别调频、风力发电平滑输出以及分布式发电和微网等领域均具有技术优势。本文研究了应用在1.5 MW风机上的飞轮储能系统,实现了功率平滑输出的目的,确定了飞轮储能系统技术指标并设计了总体方案,分析了飞轮储能系统的电动机/发电机的工作模式,为进一步能量转换系统的开发提供了依据。     

Electric buses – An energy efficient urban transportation means

Bus transit systems with electric traction are an important contribution to the post fossil fuel mobility. Most renewable energy sources provide energy in the form of electricity. Electric motors thus have promise in the development of the way “beyond oil”. The reactivation of trolley bus systems – grid bounded but also catenary free for short distances – paves this way. The design of modern trolley bus operations overcomes the existing disadvantages of conventional buses using fossil fuel. Germany has an efficient industry in this field, that offers braking energy recuperation and energy storage in modern supercapacitors as well as technical and organisational innovations for a local emission free and a low noise transit system. Gentle but powerful when starting and braking, the trolley bus is cost effective and easy to integrate into an existing infrastructure. Such an electric bus system is ecological, customer-friendly and suitable for cities. It has a high economic efficiency and it also expands the traffic planning field towards an ecological future technology. This paper shows examples at home and abroad how electric buses achieve an energy solving modern urban traffic. It gives insights into technical developments of electric vehicle equipment, cateneries with fast driving handling characteristics and the use of plain electric and hybrid powertrains.     

针对并网型风储微网的飞轮储能阵列系统控制方法CSCD

由于新能源发电存在波动性和间歇性,其大量接入时会给电网运行带来新的困难,而利用储能技术提高新能源的可调度性是当前研究的热点。为缓解新能源并网对电力系统的不良影响,针对并网型风储微网提出了一种基于飞轮储能阵列系统的分层优化控制方法,上层优化中心根据功率缺额和各台飞轮的转速建立相应充/放电优化模型,并求解相应飞轮的功率参考值;下层飞轮控制器采用双模双环控制方法,实现飞轮转速和输出功率的控制,最后通过MATLAB/Simulink仿真验证了所提控制方法的有效性和可行性。     

Experimental investigation of supercapacitor based regenerative energy storage for a fuel cell vehicle equipped with an alternator

Recently, researchers have devoted more attention to supercapacitors (SCs) to integrate with batteries in energy storage systems (ESSs) for vehicle applications. In this study, we attempted to characterize the use of SCs in the ESS for a PEM fuel cell vehicle equipped with an alternator to maximize the performance of regenerative braking. We applied lithium-ion batteries (LIBs) and SCs as energy storage devices to examine their effect on ESS. Then we used a hysteresis brake to apply controllable braking force on the flywheel to form hybrid braking (HB) and made efforts to study its behavior to suggest a braking control strategy. We also ran the whole system over the rotational speed to cover the range of driving speed. At last, we sized the SCs for the most commonly used fuel cell electric vehicle (FCEV) in Korea, i.e., Hyundai NEXO, based on the results obtained from the above study by alternator efficiencies.     

盘式和柱式飞轮转子系统临界转速分析CSCD

针对飞轮储能系统升降速实验中极限转速为9300 r/min,小于飞轮储能的最高工作转速15000 r/min,这会大幅降低飞轮储能系统的最大储能量。为提高飞轮储能实验中极限转速,从结构设计角度出发,采用理论公式分析、SAMCEF Rotor有限元仿真分析并结合实验数据来研究盘式飞轮转子和柱式飞轮转子的临界转速分布规律及其稳定性。分析发现,质量相同、结构不同的盘式飞轮转子其二阶临界转速远远超过柱式飞轮转子,两者的一阶临界转速相同。根据不同工作转速和储能量要求的飞轮转子,采取不同的结构方案,确保其达到工作转速要求并稳定运行。     

Bulk energy storage potential in the USA, current developments and future prospects

Stored energy can provide electricity during periods of high demand, as currently demonstrated with bulk storage systems such as pumped hydro storage (PHS), which accounts for only 2.5% of the current installed base load in the USA. Sites for future developments have become less available, and environmental siting issues, as well as high costs have stopped further prospects. This paper looks at the potential beyond PHS, with bulk storage systems such as compressed air energy storage (CAES) flow-batteries and 1 MW flywheel systems that can provide system stability/support at the grid, substations and distributed level. Current developments in bulk energy storage will be reviewed as well as some storage project developments incorporating wind energy and the impact on base-loaded coal and natural gas fired GT combined cycle plants. The large potential and the economic benefits for energy storage in the US will be examined.     

飞轮储能在区域电网中的调频应用及经济性分析

介绍了飞轮储能在区域电网的应用现状,提出了飞轮储能用于电网调频的经济性分析评估方法。通过美国加利福尼亚州的工程实例详细分析了飞轮储能在电网调频中的效益投资情况。结果表明,飞轮储能的投资效益比接近1,具有良好的投资回报价值;在大规模商业化应用后,收益投资比可达1．97。     

新能源发电工程储能系统容量/功率优化配置

新能源风、光发电工程中配置一定容量的储能系统,可以显著提高新能源发电的消纳水平。储能系统的容量/功率的优化配置可最大程度提高储能系统利用效率和经济性,同时将新能源风电、光伏的弃电率降低到设定的目标值。提出以全生命周期内储能系统净现值最大为目标,综合考虑储能系统全生命周期内投资、运维成本、购电成本、售电收入、充放电效率、荷电状态、储能电池寿命、弃电率等多种因素的储能系统容量/功率优化配置方法,并以青海某工程1 030 MW光伏阵列和250 MW风电场的运行数据为例,计算得到该新能源风电、光伏发电工程中净现值最大的储能系统容量/功率配置,使整个储能系统获得最优的经济性。     

飞轮储能技术及其耦合发电机组研究进展

  目的  双碳目标的提出增加了新能源电力嵌入的必要性,为了研究提高机组灵活性的方法,文章对飞轮储能技术及其耦合发电机组的相关研究进行了详细介绍。  方法  文章概括总结了飞轮储能的工作原理、研究现状与成果以及应用难点与措施,分析了研究飞轮储能的系统建模与运行策略的具体方法,并对飞轮储能分别耦合火力发电、风力发电以及太阳能发电的原理与应用特点进行了重点分析。  结果  我国的飞轮储能系统研究已经取得较为先进的成果,并且形成了一套有效的研究方法,在飞轮储能技术耦合多能源发电机组方面也进行了一定的研究。  结论  在当今环境下,飞轮储能技术耦合多能源发电机组已经成为研究趋势与重点,本文所总结内容为后续飞轮储能技术的应用提供了参考。     

Research on disturbance analysis and detection method for the magnetically suspended flywheel-based PMSM system

本文基于飞轮三相永磁同步电机的特性,研究影响飞轮电机控制性能的干扰因素并对其特性进行分析。首先建立动基座条件下飞轮转子的动力学模型,在此基础上对影响电机性能的内外多源干扰进行建模和特性分析,给出详细的干扰模型以及所包含的结构类型。针对干扰所必需的输入参数,设计并实现了飞轮干扰状态的监测系统,获取飞轮实时转速、磁偏转角和基座振动等信息。最后,给出磁悬浮储能飞轮系统实验装置和飞轮参数,为飞轮电机干扰特性验证和干扰抑制方法提供必要基础。     

Flywheel energy storage systems: Review and simulation for an isolated wind power system

In flywheel based energy storage systems (FESSs), a flywheel stores mechanical energy that interchanges in form of electrical energy by means of an electrical machine with a bidirectional power converter. FESSs are suitable whenever numerous charge and discharge cycles (hundred of thousands) are needed with medium to high power (kW to MW) during short-time periods (seconds–minutes). Monitoring of the FESS state of charge is simple and reliable as only the spinning speed is needed. The materials for the flywheel, the type of electrical machine, the type of bearings and the confinement atmosphere which all together determine the FESSs energy efficiency (>85%) are reviewed. Main FESS applications: power quality, traction and aerospace are presented. Additionally in this paper it is presented the simulation of an isolated wind power system (IWPS) consisting of a wind turbine generator (WTG), a consumer load, a synchronous machine (SM) and a FESS. A low-speed iron flywheel driven by an asynchronous machine (ASM) is sized for the presented IWPS. The simulation results with graphs for system frequency, system voltage, active powers of the different elements, and FESS-ASM speed, direct and quadrature currents are presented showing that the FESS effectively smoothes the wind power and consumer load variations.     

风力发电机用飞轮储能智能控制系统研究

针对在风力发电机上具有广泛应用前景的飞轮储能技术,设计了储能系统的矢量控制器硬件电路及实验平台、电机控制系统的主电路和驱动电路、DSP主控板、电压及电流信号的采集系统等。基于矢量控制原理,进行了电机控制系统仿真研究。仿真结果表明,该系统能够精确地实现对电机速度的跟踪。在飞轮储能与风力发电模拟系统的试验中,为了验证控制系统的响应速度及稳态精度,利用交流电网对飞轮充电,有效地实现了飞轮与电机的耦合及飞轮能量的快速存储和释放。