Control system design of hybrid fuel cell city bus

This paper introduced the design of the hybrid powertrain of the Fuel Cell City Bus demonstrated in 2008 Beijing Olympic Games. The configuration of the hybrid fuel cell powertrain was introduced. The safety of hydrogen storage and delivery system, the hydrogen leakage alarm system were developed. The real-time distributed control and diagnosis system based on the Time Trigger Controller Area Network （TTCAN） with 10 ms basic control period was developed. The concept and implementation of processor （or controller） monitor and process （or task） monitor technique based on the TYCAN were applied in this paper. The fault tolerant control algorithm of the fuel cell engine and the battery man- agement system were considered. The demonstration experience verified that the fault tolerant control was very important for the fuel cell city bus.

Simulation of Dynamic Response of Small Wind-Photovoltaic-Fuel Cell Hybrid Energy System

Renewable energy systems are of importance as being modular, nature-friendly and domestic. Among renewable energy systems, a great deal of research has been conducted especially on photovoltaic effect, wind energy and fuel cell in the recent years. This paper describes dynamic modeling and simulation results of a small wind-photovoltaic-fuel cell hybrid energy system. The hybrid system consists of a 500 W wind turbine, a photovoltaic, a proton exchange membrane fuel cell (PEMFC), ultracapacitors, an electrolyzer, a boost converter, controllers and a power converter that simulated using MATLAB solver. This kind of hybrid system is completely stand-alone, reliable and has high efficiency. In order to minimize sudden variations in voltage magnitude ultracapacitors are proposed. Power converter and inverter are used to produce ac output power. Dynamics of fuel-cell component such as double layer capacitance are also taken into account. Control scheme of fuel-cell flow controller and voltage regulators are based on PID controllers. Dynamic responses of the system for a step change in the electrical load and wind speed are presented. Results showed that the ability of the system in adapting itself to sudden changes and new conditions. Combination of PV and wind renewable sources is made the advantage of using this system in regions which have higher wind speeds in the seasons that suffers from less sunny days and vice versa.

A Novel Method for the Application of the ECMS(Equivalent Consumption Minimization Strategy)to Reduce Hydrogen Consumption in Fuel Cell Hybrid Electric Vehicles

Fuel cell hybrid electric vehicles are currently being considered as ideal means to solve the energy crisis and global warming in today’s society.In this context,this paper proposes a method to solve the problem related to the dependence of the so-called optimal equivalent factor(determined in the framework of the equivalent consumption minimum strategy-ECMS)on the working conditions.The simulation results show that under typical conditions(some representative cities being considered),the proposed strategy can maintain the power balance;for different initial battery’s states of charge(SOC),after the SOC stabilizes,the fuel consumption is 5.25 L/100 km.

Hybrid dynamic model of polymer electrolyte membrane fuel cell stack using variable neural network

The polymer electrolyte membrane（PEM） fuel cell has been regarded as a potential alternative power source,and a model is necessary for its design,control and power management.A hybrid dynamic model of PEM fuel cell,which combines the advantages of mechanism model and black-box model,is proposed in this paper.To improve the performance,the static neural network and variable neural network are used to build the black-box model.The static neural network can significantly improve the static performance of the hybrid model,and the variable neural network makes the hybrid dynamic model predict the real PEM fuel cell behavior with required accuracy.Finally,the hybrid dynamic model is validated with a 500 W PEM fuel cell.The static and transient experiment results show that the hybrid dynamic model can predict the behavior of the fuel cell stack accurately and therefore can be effectively utilized in practical application.

Hybrid system-a promising way solving future energy problems

With the increasing demand for electricity,an efficiency improvement and thereby reduced CO2 emissions of the power plants are expected in order to reach the goals set in the Kyoto protocol.In comparison to conventional systems,the hybrid-systems with the use of synergetic effects offer the possibility to provide a substantial contribution to spare our natural resources and protect our environment.Combined Cycle Power Plants belongs innately hybrid system in the centralized energy market.They can provide large amounts of power and have a quick start-up time.The MGT/FC hybrid system is quite promising in the decentralized energy market.It is widely used in stand-alone applications.Furthermore,the combination of fossil and renewable power plant technologies contains a large synergy potential to increase the efficiency of processes for power plants.New materials,innovative cooling technology,new combustion concepts and optimized production methods are needed to make the potential of these new technologies accessible for a quantum leap in the efficiency.For this it needs considerable research work and good coordinated research projects between the state,industry,research laboratories and universities.

Energy Analysis of a Combined Solid Oxide Fuel Cell with a Steam Turbine Power Plant for Marine Applications

Strong restrictions on emissions from marine power plants(particularly SOx,NOx)will probably be adopted in the near future.In this paper,a combined solid oxide fuel cell(SOFC)and steam turbine fuelled by natural gas is proposed as an attractive option to limit the environmental impact of the marine sector.The analyzed variant of the combined cycle includes a SOFC operated with natural gas fuel and a steam turbine with a single-pressure waste heat boiler.The calculations were performed for two types of tubular and planar SOFCs,each with an output power of 18 MW.This paper includes a detailed energy analysis of the combined system.Mass and energy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of the combined cycle.In addition,the effects of using natural gas as a fuel on the fuel cell voltage and performance are investigated.It has been found that a high overall efficiency approaching 60%may be achieved with an optimum configuration using the SOFC system.The hybrid system would also reduce emissions,fuel consumption,and improve the total system efficiency.

An adaptive fuel cell hybrid vehicle propulsion sizing model

As we enter the age of electrochemical propulsion,there is an increasing tendency to discuss the viability or otherwise of different electrochemical propulsion systems in zero-sum terms.These discussions are often grounded in a specific use case;however,given the need to electrify the wider transport sector it is evident that we must consider systems in a holistic fashion.When designed adequately,the hybridisation of power sources within automotive applications has been demonstrated to positively impact fuel cell efficiency,durability,and cost,while having potential benefits for the safety of vehicles.In this paper,the impact of the fuel cell to battery hybridisation degree is explored through the key design parameter of system mass.Different fuel cell electric hybrid vehicle(FCHEV)scenarios of various hydridisation degrees,including light-duty vehicles(LDVs),Class 8 heavy goods vehicles(HGVs),and buses are modelled to enable the appropriate sizing of the proton exchange membrane(PEMFC)stack and lithium-ion battery(LiB)pack and additional balance of plant.The operating conditions of the modelled PEMFC stack and battery pack are then varied under a range of relevant drive cycles to identify the relative performance of the systems.By extending the model further and incorporating a feedback loop,we are able to remove the need to include estimated vehicle masses a priori enabling improving the speed and accuracy of the model as an analysis tool for vehicle mass and performance estimation.

Performance evaluation of microbial fuel cell for landfill leachate treatment: Research updates and synergistic effects of hybrid systems

Over half of century,sanitary landfill was and is still the most economical treatment strategy for solid waste disposal,but the environmental risks associated with the leachate have brought attention of scientists for its proper treatment to avoid surface and ground water deterioration.Most of the treatment technologies are energy-negative and cost intensive processes,which are unable to meet current environmental regulations.There are continuous demands of alternatives concomitant with positive energy and high effluent quality.Microbial fuel cells(MFCs)were launched in the last two decades as a potential treatment technology with bioelectricity generation accompanied with simultaneous carbon and nutrient removal.This study reviews capability and mechanisms of carbon,nitrogen and phosphorous removal from landfill leachate through MFC technology,as well as summarizes and discusses the recent advances of standalone and hybrid MFCs performances in landfill leachate(LFL)treatment.Recent improvements and synergetic effect of hybrid MFC technology upon the increasing of power densities,organic and nutrient removal,and future challenges were discussed in details.

基于近端策略优化算法的燃料电池混合动力系统综合价值损耗最小能量管理方法

为了降低市域动车组燃料电池混合动力系统运行燃料经济成本,提升燃料电池耐久性,该文提出一种基于近端策略优化算法的能量管理方法。该方法将混合动力系统能量管理问题建模为马尔可夫决策过程,以综合考虑燃料经济性和燃料电池耐久性的综合价值损耗最小为优化目标设置奖励函数,采用一种收敛速度较快的深度强化学习算法—近端策略优化算法求解,实现负载功率在燃料电池和锂电池间的合理有效分配,最后,采用市域动车组实际运行工况进行实验验证。实验结果表明,在训练工况下,所提方法相较基于等效氢耗最小能量管理方法和基于Q-learning能量管理方法,综合价值损耗分别降低19.71%和5.87%;在未知工况下,综合价值损耗分别降低18.05%和13.52%。结果表明,所提方法能够有效降低综合价值损耗,并具有较好的工况适应性。

Optimization of Renewable Energy Power System for Small Scale Brackish Reverse Osmosis Desalination Unit and a Tourism Motel in Egypt

The main objective of this work is to design an optimal—efficient economic power renewable energy system that feeds the required electric load of a small scale brackish reverse osmosis desalination unit and a tourism motel located in Hurghada, Egypt. Four renewable energy power systems are presented in this paper to select the most optimum one of them. These suggested renewable energy systems are PV-wind hybrid system, stand-alone wind system, stand-alone photovoltaic system and PV-wind-fuel cell hybrid system. The sizing, optimization and economic estimation of the proposed systems were performed using HOMER software. HOMER solves the optimization problem to minimize the global cost and provides the optimum wind turbine, PV, battery and fuel cell ratings. In addition, a comparison between the four different suggested power system configurations is illustrated in details. PV-wind hybrid system realized the lowest net present cost and levelized cost of energy. Also, this system was able to provide energy approximately all the day. The battery state of charge varies between 83% and 99% and it was found that, the PV-wind hybrid system is more suitable than the others for the selected site and the suggested electrical load.

燃料电池船舶混合动力系统能量管理研究综述

在“双碳”目标下,发展燃料电池船舶是实现航运业转型升级和低碳化的重要发展方向之一。面对当前燃料电池上船的诸多问题,混合动力系统成为燃料电池船舶应用的有效解决方案,其能量管理的研究也成为核心研究方向之一。系统梳理燃料电池船舶的发展概况,针对燃料电池船舶多类型能源能量管理中涉及的能量调度问题以及变换器功率分配问题进行综述;分析各类方法的优缺点及其在实船上应用的可能性;探讨燃料电池船舶推广可行性和发展方向,以期能为技术创新和工程应用提供参考。

基于模型预测框架的燃料电池汽车混合动力系统能量管理

混合动力系统作为燃料电池汽车的关键组成部分,系统的能耗与寿命优化是推动其进一步商业化发展的关键,而能量管理策略(EMS)在提高燃料电池汽车混合动力系统的效率和燃料经济性方面发挥着重要作用。为有效降低混合动力系统的内部损耗,进一步提高系统经济性,提出了一种基于模型预测框架的混合动力系统能耗优化能量管理控制方法。首先构建包含动力系统内部损耗与氢气消耗的目标函数,然后利用模型预测架构求解目标函数来控制燃料电池的输出电流,以实现合理的能量分配,最后在Matlab中进行仿真,验证所制定方法的合理性和有效性。与应用较为广泛的等效氢耗最小策略(ECMS)相比,结果表明所提方法可以显著降低动力系统的内部损耗和氢气消耗。此外,该策略还可以有效保持蓄电池的荷电状态(SOC),延长动力系统的使用寿命。

燃料电池船复合储能容量优化与配置经济性分析

复合储能系统可改善由船舶负载功率波动引起的燃料电池寿命损耗问题,但配置成本限制了其在燃料电池船上的广泛应用。为合理配置储能容量,使船舶动力系统设计具备长期的可靠性,提出了一种计及复合储能系统全寿命周期的容量优化配置方法。在构建各电源系统模型的基础上,建立包括购置成本、维护成本、置换成本和能耗成本的复合储能系统全寿命周期成本模型,并采用雨流计数法来评估储能的置换成本。最后依据“Alsterwasser”号燃料电池船的典型功率需求数据,以储能设备的容量参数、燃料电池的输出功率和电源系统的运行参数为优化变量,采用灰狼优化算法进行求解。通过不同储能类型和优化目标下的配置方案对比,验证了所提方法的经济性。

燃料电池汽车动力系统及能量管理策略研究进展

动力系统是燃料电池汽车(FCV)的核心,可分为单一式系统与混合动力系统两大类,其中,将燃料电池与辅助电源相结合组成“电-电”混合动力系统,已成为业界主流。本文根据辅助电源类型的不同,提出3类FCV混动系统的构建方案,分别为燃料电池+动力电池方案、燃料电池+超级电容方案、燃料电池+动力电池+超级电容方案,并对各方案的优势和劣势进行比较。同时,本文综述了近年来国内外学者提出的面向FCV的代表性能量管理策略,从理论基础与求解方法的差异出发,将现有燃料电池汽车的能量管理策略分为3类:基于规则定义的策略、基于最优化方法的策略以及基于机器学习的策略,并总结了各类策略在最优性与实时性等方面的优势和劣势。其中,基于规则定义的策略最易实现,在工程应用中最为普遍,但无法实现性能最优;基于最优化方法的策略能够接近甚至达到理论最优,但存在计算量过大、计算耗时过长、实时性差等问题;以强化学习为代表的基于机器学习的策略有望在最优性与实时性之间实现理想的平衡,但目前还存在模型训练耗时长、试错代价高等困难,在实车应用层面还存在一定挑战。基于文献研究与分析,本文提出以下观点:1)以大功率燃料电池为核心的功率混合型系统是FCV混动系统的未来发展方向;2)必须进一步提升智能化程度,根据实际使用场景开发具有个性化的能量管理策略;3)亟需建立关于燃料电池汽车能量管理策略的综合评价体系。

考虑电堆性能一致性的燃料电池混合动力系统多目标优化能量管理方法

为优化燃料电池混合动力系统(fuel cell hybrid power system,FCHPS)并延长其使用寿命,该文提出一种考虑电堆性能一致性的多目标优化能量管理方法。该方法的目的是降低系统等效氢耗、提高燃料电池系统内电堆组运行效率的同时限制锂电池荷电状态(state of charge,SOC)波动。由于电堆组的性能会在实际运行过程中发生退化,因此该方法还考虑了电堆组的性能状态差异,通过限制性能较差电堆的运行压力,以延长系统寿命。为实现这一目的采用樽海鞘群算法(salpswarmalgorithm,SSA)对目标函数进行优化求解,得到系统最优功率分配。最后,基于RT-LAB半实物仿真平台,将所提方法与有限状态机控制方法进行对比,实验结果表明所提出的方法能够有效降低系统氢耗,提高电堆组效率的同时减缓性能较差电堆的功率波动,维持系统一致性,有利于系统长期稳定运行。

基于改进型等效氢耗的车用燃料电池混合动力系统能量管理方法研究

[目的]等效氢耗作为一种针对燃料经济性优化的方法,其在储能系统荷电状态跟随方面表现欠佳,故需对其进行改进以实现区间荷电状态的动态平衡。[方法]在传统等效氢耗算法基础上,对系统的氢耗函数进行了优化;通过加入电压平衡系数,以确保超级电容在车辆运行过程中不会出现过充或过放的情况,进而通过极小值求解,实现了对系统功率的实时分配。[结果及结论]基于数轨电车的运行数据,对所提出的方法在半实物仿真平台上进行了验证。实验结果表明,所提出的改进型等效氢耗算法能够实现复杂工况下的混合动力系统能量分配,所加入的电压平衡系数能够保证车辆区间末端超级电容的电压在合理的区间内。

基于最优功耗的燃料电池/超级电容混合动力系统能量管理方法研究

[目的]随着科技发展与我国“双碳”进程的稳步推进,氢能在城市交通中的应用也日益增加;为降低数轨电车用燃料电池/超级电容混合动力系统整体能耗,提出了一种基于最优功耗的能量管理方法。[方法]以数轨电车在不同运行状态下的功耗分布为基础,通过拟合近似的方式,并结合燃料电池系统与超级电容系统的功耗模型,联合构建了混合动力系统的瞬时功耗函数;通过对功耗函数的寻优与求解,得到燃料电池系统的最佳输出功率;基于半实物仿真平台及数轨电车的实际运行数据,验证了所提方法的在线控制能力。[结果及结论]燃料电池系统在所提方法的控制下,在复杂工况下保持了较为稳定的输出功率,且平均电氢转化效率达54.84%,这能够有效降低数轨电车的运维成本。

基于甲醇燃料的航空燃料电池内燃机混合动力系统性能分析

为了实现航空碳减排的时代需求,亟需在航空燃料体系和航空动力系统方向实现技术革新。本文提出了基于甲醇燃料的航空燃料电池内燃机混合动力系统方案,甲醇通过机载在线催化重整制氢为燃料电池供氢,燃料电池和内燃机发出的电能带动电动螺旋桨进行工作。进行了模块化建模方法和混合动力系统性能仿真分析研究,结果表明:混合动力系统的发电效率达到了55%,相比甲醇内燃机有了15%绝对值的效率提升,有助于降低燃料消耗。进行了混合动力系统性能参数影响规律分析,结果表明:混合动力系统的效率随着压比的增大而提高,随着燃料利用率的提高而呈现先升高后降低的效果。进行了混合动力系统的?分析,结果显示:混合动力系统中?效率最高的部件是燃料电池,?损最大的部件是重整器。质量分析结果表明:混合动力系统的功率密度达到0.488 kW/kg。

基于多目标优化的燃料电池汽车实时能量管理策略

为了降低混合动力系统的燃料消耗并延缓动力元件的老化,提出了一种基于多目标优化和路况分类的能量管理策略(EMS)。首先,构建了燃料电池与锂电池的电气模型,并引入了等效氢耗模型和燃料电池老化模型。其次,设计了基于规则的多模式EMS,在此基础上,为了进一步降低系统的等效氢耗,并延长其使用寿命,基于多目标白鲸算法(MOBWO)对EMS参数进行优化。再次,为了使所设计的EMS适用于不同的路况,提出了基于长短期记忆网络(LSTM)的驾驶路况实时分类方法,旨在根据分类结果切换EMS的控制参数以达到最优效果。最后,在仿真平台上对所提算法进行分析。结果表明:与基于规则的方法相比,所提方法氢耗量降低了2.3%,燃料电池的老化程度降低了1.02%,验证了所提EMS能够有效降低混合系统的燃料消耗,并且能够延缓燃料电池老化,从而提升了系统的经济性和耐久性。

Function approximation reinforcement learning of energy management with the fuzzy REINFORCE for fuel cell hybrid electric vehicles

In the paper,a novel self-learning energy management strategy(EMS)is proposed for fuel cell hybrid electric vehicles(FCHEV)to achieve the hydrogen saving and maintain the battery operation.In the EMS,it is proposed to approximate the EMS policy function with fuzzy inference system(FIS)and learn the policy parameters through policy gradient reinforcement learning(PGRL).Thus,a so-called Fuzzy REINFORCE algorithm is first proposed and studied for EMS problem in the paper.Fuzzy REINFORCE is a model-free method that the EMS agent can learn itself through interactions with environment,which makes it independent of model accuracy,prior knowledge,and expert experience.Meanwhile,to stabilize the training process,a fuzzy baseline function is adopted to approximate the value function based on FIS without affecting the policy gradient direction.More-over,the drawbacks of traditional reinforcement learning such as high computation burden,long convergence time,can also be overcome.The effectiveness of the proposed methods were verified by Hardware-in-Loop ex-periments.The adaptability of the proposed method to the changes of driving conditions and system states is also verified.