小功率质子交换膜燃料电池电源供氢系统的研究

通过对几种不同贮氢方法的比较,认为金属氢化物贮氢是一种很好的方法,对一种稀土镍系金属贮氢器进行了放氢实验,结果表明不同的实验条件对贮氢器放氢量有不同的影响,其中在恒温水浴条件下放氢较好,在室温自然对流条件下放氢较差,最后针对小功率电源的特点,对贮氢系统的开发提出了一些建议。     

70 kW燃料电池热电联产系统水热管理研究

质子交换膜燃料电池堆的电效率约为50%,电化学反应剩余的能量要以热量的形式散失,造成巨大能量浪费,开发基于燃料电池的热电联产系统可以高效地产生电力和热水,并显著提高系统的能量效率。在MATLAB/Simulink平台上搭建了70 kW级燃料电池热电联产系统,包括燃料电池电模型、热管理模型和热电联产系统综合动态模型,并开发了一种智能控制算法进行水热管理,将电堆运行温度控制在70℃左右,在保证电堆正常运行的前提下,提升热能回收效率并降低系统寄生功率。结果表明该系统可以有效地回收燃料电池反应所产生的废热,在增大外部负载提高电堆电效率的同时,热电联产效率会逐渐增高然后降低,热电联产最高效率可以达到83.5%。     

天然气制氢及质子交换膜燃料电池的研究

文章简要介绍了质子交换膜燃料电池(PEMFC)的发展历史，PEMFC的原理、结构和组成，重点叙述了质子交换膜燃料电池系统研制中需要解决的若干问题及其对燃料电池稳定运行的影响。介绍了天然气水蒸汽重整制氢作为质子交换膜燃料电池氢源的技术路线。     

应用于平抑风功率的燃氢燃气轮机储能系统控制策略研究

储能技术可用于提高风电并网能力,因此其储能系统及控制策略成为研究热点。提出将燃氢燃气轮机作为储能系统主要部分,低通滤波器结合模糊控制作为其平抑风功率的控制策略。通过设定储氢罐容量,对15台1.5 MW风机的历史风功率数据进行了处理。结果表明：低通滤波器结合模糊控制能有效平抑风功率至限制值,实现平抑指标,并得到储氢罐容量的设置限制;可实现储能时燃气轮机不工作,耗能时燃气轮机工作,当储氢罐容量为0.017 m³时,燃气轮机输出功率为0.1 MW。在将燃气轮机作为平抑风功率的储能系统时,需将燃气轮机的启停控制作为今后的研究重点。     

基于最大净功率输出的PEMFC阴极供气系统优化控制研究

通过建立质子交换膜燃料电池（PEMFC）阴极供气系统数学模型,分析空气压缩机电压和背压阀开度对系统净功率输出的影响;针对负载电流变化,研究PEMFC系统对应的最优过氧比和最优阴极压力,建立最大输出净功率-过氧比-阴极压力寻优表;考虑过氧比和阴极压力之间的耦合关系,基于辨识出的传递函数矩阵,设计针对空气压缩机电压和背压阀开度的前馈解耦控制器,优化氧气供给和压力控制,并进行相应的仿真验证。结果表明,所提解耦控制器能有效减小过氧比和阴极压力之间的耦合影响,在实现最大净功率闭环控制的同时,具有更快的响应速度和更小的超调量。     

基于两级全钒液流电池的风电储能系统的功率优化分配控制

为更好地利用储能系统平抑风电功率波动,采用了两级全钒液流电池(VRB)储能的功率优化分配及控制策略。基于直驱型永磁同步风电系统的工作原理及系统变流器的控制策略,建立了全钒液流电池等效电路模型,采用基于VRB组荷电状态(SOC)的双模式切换的双闭环控制策略,通过比较每级电池组荷电状态值确定优选目标,以VRB组最大充放电功率为电池组安全充放电的约束条件,提出两级VRB组的功率优化分配控制策略,利用Matlab/Simulink仿真平台,在变风速条件下对不同荷电状态的两级VRB储能系统平抑风电功率波动进行仿真,并与功率平均分配策略作对比。结果表明,两级VRB储能系统功率优化分配控制策略能有效平抑风电机组功率波动,同时,还确保了电池组工作于安全运行区域,有效地减少了VRB组的充放电次数,延长了电池组的寿命。     

车用燃料电池发动机系统的研究与应用

介绍了质子交换膜燃料电池发动机系统的设计研究，提出了将其集成为车用发动机系统的设计方案。     

小型风电系统MPPT模糊／PID控制仿真研究

根据最大功率点跟踪的基本原理及常用风力发电控制系统的特点,提出了一种模糊／PID双模控制。具有在线参数调整的自适应占空比扰动法,该方法同步精度高,动态响应快,能迅速调整发电机与负载之间的功率匹配,减少最大功率点的振荡,使风力机以最佳叶尖速比运行。通过仿真实验表明,采用模糊／PID控制电路,能够快速准确的跟踪风力发电系统的最大功率点,改善最大功率点的振荡,减少能量损失,提高能量转换效率。     

直驱风电系统最大功率捕获技术的仿真分析

对直驱风电系统最大功率捕获技术进行了仿真分析.在仿真过程中,通过控制发电机组转速来实现风力机的最佳运行,使功率系数、风力机转速及输出机械功率等参数都能运行在不同风速下的最优值,从而最大限度地捕获风能.当发电机组达到最优运行时,再通过控制整流器使其输出恒定的电压.     

车用质子交换膜燃料电池发动机系统控制技术现状研究

质子交换膜燃料电池(PEMFC)以其高能量密度、工作温度低、无污染排放、结构紧凑等优点被公认为发展前景最好的汽车动力源之一,对车用(PEMFC)发动机系统的氢气/空气供给系统、水/热管理系统、安全系统、压力,温湿度控制系统的技术现状进行了系统分析,对PEMFC发动机的控制理论,如模糊控制、预测控制与应用技术发展方向进行了研究。     

Power smoothing control for wind farms using flywheel based energy storage

在风电场增设飞轮储能装置可以有效地平抑风电场的功率波动,提高电网的风电接纳能力。本文采用在风电场出口母线处接入飞轮储能装置,通过分析风电系统和飞轮储能装置的特性,提出了一种基于瞬时功率理论的有功功率平滑控制策略。在传统低通滤波器的基础上,增加高通滤波器,对网侧有功功率的快速扰动成分进行处理,最终通过低通、高通滤波器来获得飞轮装置的补偿功率,达到对网侧有功功率波动进行抑制的目的。最后利用Matlab/Simulink进行仿真验证,仿真结果表明,文中的控制策略可以较好地实现电网侧有功功率的平滑控制,减小有功功率波动。     

Power conditioning for a wind–hydrogen energy system

In addition to the efforts to reduce the costs of renewable energy technologies and electrolyzers, the development of suitable controllers are needed for cost-competitive electricity production by renewable-hydrogen power plants. In this paper, a novel control is proposed for a wind-electrolysis system, which match the wind power output to the electrolyzer power requirements, thus gaining in system performance. It basically consists in continuously shaping the power reference of a conventional maximum power point tracking algorithm. Thus, high aerodynamic power conversion efficiency is achieved fulfilling at the same time the electrolyzer specifications. This control strategy is developed using concepts of the reference conditioning technique and of the sliding mode control theory. The proposed control algorithm is extremely simple, easy to implement and robust to parameter uncertainties.     

用于风电功率平抑的飞轮储能阵列功率协调控制策略

风电输出功率存在随机性和波动性的问题,使得电网调频难度加大.采用飞轮储能匹配风电的形式可以减小其功率波动,提高并网能力.以交流母线并联的飞轮储能阵列为研究对象,首先针对现有功率分配策略中存在的问题,提出一种考虑功率分配上限和能使各单元荷电状态(SOC)趋于一致的功率协调控制策略.同时为保证功率控制精度和储能系统的响应速...     

Power smoothing in large wind farms using optimal control of rotating kinetic energy reserves

In large wind farms, self‐induced turbulence levels significantly increase the variability of generated power in a range of time scales from a few seconds to several minutes. In the current study, we investigate the potential for reducing this type of variability by dynamically controlling the rotating kinetic energy reserves that are present in the farm's wind turbines. To this end, we reduce the burden of frequency regulation on remaining conventional units when they are displaced in favor of wind turbines. We focus on the development of a theoretical benchmark framework in which we explore the trade‐off between high energy extraction and low variability using optimal coordinated control of multiple turbines subject to a turbulent wind field. This wind field is obtained from a large‐eddy simulation of a fully developed wind farm boundary layer. The controls that are optimized are the electric torque and the pitch angles of the individual turbines as function of time so that turbines are accelerated or decelerated to optimally extract or store energy in the turbines' rotating inertia. Results are presented in terms of Pareto fronts (i.e., curves with optimal trade‐offs), and we find that power variations can be significantly reduced with limited loss of extracted energy. For a one‐turbine case, such an optimal control leads to large potential reductions of variability but mainly for time scales below 10 s if we limit power losses to a few percent. Variability over longer time scales (10–100 s) is reduced considerably more for coordinated control. For instance, restricting the energy‐loss incurred with smoothing to 1%, and looking at time scales of 50 s, we manage to reduce variability with a factor of 6 for a coordinated case with 24 turbines, compared with a factor of 1.4 for an uncoordinated case. Copyright © 2014 John Wiley & Sons, Ltd.     

光伏电站复合储能电压波动抑制双层优化控制方法

大规模光伏电站的不断接入为电力系统的安全稳定运行带来了巨大挑战。为解决光伏电站出力不确定性所造成的功率波动问题,提高光伏电站在并网点处电压的稳定性,文章采用由蓄电池与超级电容组成的复合储能一体化控制方法,提高光伏并网点电压稳定水平。首先研究由光伏电源、复合储能构成的典型复合储能系统拓扑结构下储能双层优化控制策略;其次,在不同储能介质的荷电状态与充放电特性模型基础上,研究基于不同光伏并网点电压波动场景的多储能介质组合电压波动抑制优化控制模型及其求解算法;最后,以并网光伏电站数据为基础,建立光伏复合储能电压波动优化控制仿真模型。仿真结果及其分析表明,文章所提出的基于复合储能的并网点电压波动抑制模型能够有效提升并网点电压稳定性能。     

Modelling, control and simulation of an overall wind energy conversion system

More and more conversion systems have been proposed to capture wind energy in order to produce electrical power. In this paper, an energetic macroscopic representation is used to describe such systems composed of very different parts. This representation yields the simulation model of the overall system based on energetic considerations. Moreover, a control structure can be deduced from this representation by simple inversion rules. Hence, the different strategies of wind turbine management can be shown by the theoretical control structure. In order to illustrate this modelling and control methodology a 750 kW wind energy conversion system is studied and simulated.     

Techno-economic analysis of hydrogen energy for renewable energy power smoothing

With the increasing proportion of renewable energy (mainly wind power and photovoltaic) connected to the grid, the fluctuation of renewable energy power brings great challenges to the safe and reliable operation of power grid. As a clean, low-carbon secondary energy, hydrogen energy is applied in renewable energy (mainly wind power and photovoltaic) grid-connected power smoothing, which opens up a new way of coupling hydrogen storage energy with renewable energy. This paper focuses on the optimization of capacity of electrolyzers and fuel cells and the analysis of system economy in the process of power output smoothing of wind/photovoltaic coupled hydrogen energy grid-connected system. Based on the complementary characteristics of particle swarm optimization (PSO) and chemical reaction optimization algorithm (CROA), a particle swarm optimization-chemical reaction optimization algorithm (PSO-CROA) are proposed. Aiming at maximizing system profit, the capacity of electrolyzers and fuel cells are constrained by wind power fluctuation, and considering environmental benefits, government subsidies and time value of funds, the objective function and its constraints are established. According to the simulation analysis, by comparing the calculated results with PSO and CROA, it shows that PSO-CROA effectively evaluates the economy of the system, and optimizes the optimal capacity of the electrolyzers and fuel cells. The conclusion of this paper is of great significance for the application of hydrogen energy storage in the evaluation of power smoothness and economy of renewable energy grid connection and the calculation of economic allocation of hydrogen energy storage capacity.     

基于超级电容储能的风电并网功率调节控制系统

风能是一种随机变化的能源,风速变化会导致风电机组输出功率的波动,对电网的电能质量产生影响,使用储能装置可以改善风电质量。通过在风电场并网的交流侧母线上并联超级电容储能单元,能实现对风电场功率的调节,减小功率的波动。文章设计了风电场并网及储能系统各部分的控制策略,在Matlab/Simulink仿真环境下创建了系统的仿真模型,验证了控制策略的正确性。仿真系统最终实现了电机侧变流器最大风能跟踪、电网侧变流器单位功率因数并网和超级电容储能单元对风电场并网功率的调节。     

Transient simulation and comparative assessment of a hydrogen production and storage system with solar and wind energy using TRNSYS

This paper uses the TRNSYS software to investigate the hourly energy generation potential, storage, and consumption via an electrolyzer and a fuel cell in the Canadian city of Saskatoon, which is a region with high solar and wind energy potential. For this purpose, a location with an area of 10,000 m² was considered, in which the use of solar panels and vertical-axis wind turbines (VAWTs) were simulated. In the simulation, the solar panels were placed at specific distances, and the energy generation capacity, amount of produced hydrogen, and the energy available from the fuel cell were examined hourly and compared to the case with wind turbines placed at standard distances. The results indicated energy generation capacities of 1,966,084 kWh and 75,900 kWh for the solar panels and the wind turbines, respectively, showing the high potential of solar panels compared to wind turbines. Moreover, the fuel cells in the solar and wind systems can produce 733,077 kWh and 22,629 kWh of energy per year, respectively, if they store all of the received energy in the form of hydrogen. Finally, the hourly rates of hydrogen production by the solar and wind systems were reported.     

Power converter topologies for wind energy conversion systems: Integrated modeling,control strategy and performance simulation

This paper presents new integrated model for variable-speed wind energy conversion systems, considering a more accurate dynamic of the wind turbine, rotor, generator, power converter and filter. Pulse width modulation by space vector modulation associated with sliding mode is used for controlling the power converters. Also, power factor control is introduced at the output of the power converters. Comprehensive performance simulation studies are carried out with matrix, two-level and multilevel power converter topologies in order to adequately assert the system performance. Conclusions are duly drawn.