风电光伏波动性电源对电解水制氢电解槽影响的研究进展北大核心CSCD

通过可再生能源电解水制氢,用于交通、工业等亟需脱碳的领域,是实现绿色可持续发展的重要技术路径。可再生能源具有波动性特征,风电表现为实时随机波动,而光伏发电表现为较为规律的昼夜周期特性。当电解槽输入波动性电源时,电解槽电压和电流发生变化,电流变化幅度明显高于电压。本文综述了碱性电解槽和质子交换膜电解槽在波动性电源输入下的性能衰退机制和材料劣化机理。对于碱性电解槽,波动性电源变化在分钟级以下时,电解槽无法快速跟随响应,导致反应平衡和热平衡无法建立,可能产生电极催化剂溶解、聚集,隔膜机械损伤,电解液析出堵塞反应通道等现象,使得电解槽性能发生衰减。对于质子交换膜电解槽,电源波动性导致阳极催化剂溶解、迁移、沉积和聚集,隔膜由于局部热点和羟基自由基攻击发生降解,双极板发生溶解和氧化腐蚀,导致电解槽性能下降。基于波动性对电解槽的工况-材料-结构-性能影响规律,进行正向设计开发,研究缓解策略,提升电解槽抵抗电源波动性能力,从而增加可再生能源利用率,对于降低电解水制氢成本、推动规模化应用具有重要意义。     

电解水制氢厂站经济性分析北大核心CSCD

氢能是支撑智能电网和可再生能源发电规模化的最佳能源载体,发展电解水制氢是实现碳减排的重要技术路径。当前,电解水制氢成本较高,尚不具备在工业、交通、建筑等领域大规模应用的竞争力。本文对电解水制氢厂站的全生命周期成本进行研究,比较不同技术路线下电解水制氢的成本构成。结果表明,设备购置成本、电力成本和设备耐久性是影响电解水制氢综合成本的关键因素。碱性电解槽由于具有更低的设备购置成本,综合制氢成本低于质子交换膜电解槽。提高电解槽运行温度、开发高效率电解槽以及提高电解槽耐久性可显著降低电解制氢厂站的全生命周期电耗,从而降低制氢综合成本。分析表明,每降低制氢电耗1 k Wh/Nm^(3),可降低氢气平准化成本幅度为1.1 P元/Nm^(3)(P是电价,元/kWh);当电价更低时,氢气的平准化成本也相应降低,电价降低0.01元/kWh,氢气平准化成本的降幅为0.057元/Nm^(3)。     

风光互补与电解水制氢系统负荷的协调稳定运行

电解水制氢作为一种新型储能手段，可作为调整风光能源输出电力的绿色手段。该文以风力发电、光伏发电、电解制氢与燃料电池为研究对象，通过对风光互补发电系统与电解水制氢系统的输出输入功率进行建模仿真，协调优化控制风光电、电解槽、燃料电池以及系统负载的负荷变化要求，改善了风光发电电解水制氢系统与系统负荷之间的负荷不平衡问题，为风光互补可再生能源系统的稳定运行提供了理论依据。     

低边有源钳位交错反激式微型光伏逆变器设计

以微型光伏逆变器为研究对象,设计基于低边有源钳位的交错反激式光伏逆变器。该逆变系统使用STM32F103ZET6作为主控芯片,将两路反激变换器交错并联,主功率开关管获得电压钳位,实现零电压开通(ZVS),从而进一步提升逆变器的输出效率,同时提高系统的功率等级并减小电流纹波。通过200W微型光伏逆变器系统的仿真和实验研究验证该系统的理论方法正确,样机设计结果表明:该微型光伏逆变器能够输出正弦度较好的电流,总谐波失真(THD)小于3%,效率93%,系统运行稳定可靠。     

一种应用于新能源联合供电系统的新型多功能变换器

提出一种适用于新能源联合供电系统的新型多功能变换器,具有双输入、双输出、仅新能源输入、仅储能单元输入4种功能。当输入源和输出功率变化时系统可正常工作,适用于新能源发电随机性和间接性的特点,保证供电可靠性,使能源具有高利用率。通过控制两输入源之间的功率器件可使得双输入时的两输入源同时供电,双输出和任一单输入时实现交错控制,减小输入电流纹波。缓冲电容的引入,使变换器在各种工作情况下均具有高电压增益,低功率器件电压应力,特定情况下实现双输出和单输入时电感自动均流,减小控制难度。详细分析新型变换器的拓扑构成,各功能下变换器工作原理和输入输出关系、电压电流应力,最后通过实验验证理论分析的正确性。     

基于CCM交错并联Boost温差发电技术的研究

温差发电是利用温差半导体材料的赛贝克效应产生电能的一种新型发电方式,Boost变换电路是其工作的核心部分。文章分析了在电感电流连续模式(CCM)下两相交错并联Boost电路的拓扑结构及其各工作状态模型,得出了交错并联Boost电路抑制纹波的理论依据。在理论分析的基础上,进一步提出了将其应用于温差发电过程中电压的控制和最大功率跟踪,并进行了相关实验分析。理论和实验证明,该电路具有电压控制精度高、纹波系数小等优点,并最终通过最大功率跟踪技术大幅提升了温差发电的效率。     

光伏并网逆变器辅助电源设计

太阳能是清洁安全可靠的可再生能源,采用光伏并网技术的太阳能发电已成为应用面最广的光伏新能源应用技术。基于电流型PWM控制芯片UCC2801设计了一种光伏并网逆变器用辅助电源,采用4路输出的单端反激式拓扑,由光伏并网逆变器的直流母线供电,并采用电压基准源及光耦实现隔离反馈。试验结果表明,该辅助电源输入电压范围宽、输出纹波小、交叉负载调整率低,还能防止反复启停及在电源启动后自动关断。     

氢能技术的现状与未来（下）

1.水电解制氢 在不同的工作温度下,电解槽的槽电压随电流密度而变化。电解效率的定义为:产生氢的能量(高热值或低热值)与消耗的电能之比,这里我们用低热值。一台“好的”电解槽应当是在尽可能高的电流密度下有尽可能低的电压值。这两个条件是互相制约的,通过研究找出他们的最佳点。在给定温度下,水电解的最小电压和有效电压之间的电压差主要取决于欧姆电阻和阴阳极的过电压,影响槽电压的主要因素是工作温度。 按工作温度不同,电解槽可分为几类。固态氧化物电解制氢发生在约1000℃,具有超过100％电解效率的可能,因为是靠外加热来维持的。这项技术在美国、俄国、日本和德国仍处在研究阶段,其产业化还需要几年的     

质子交换膜电解水制氢技术在电厂的应用

质子交换膜(PEM)电解水制氢技术具有工作电流密度高,电解效率高,反应无污染、质量轻、结构紧凑等优点,该技术的小型电解水制氢设备在发电厂氢冷发电机组领域具有广泛的应用前景。首先介绍了PEM电解水制氢技术的工作原理及技术优势,通过与碱性电解水制氢技术方案的定量结果进行对比,分析了PEM电解技术在电厂氢冷发电机组方面应用的技术方案、设备组成及经济可行性,进一步展望了PEM电解水技术在电厂及其他民用领域的发展前景。     

双极性直流微网多交错并联电压平衡器协调控制

为了实现双极性直流微网低纹波稳定运行,对多台交错并联型电压平衡器并联运行系统进行研究。交错并联的变流器需要进行相间均流控制,通过理论推导得出电感电流偏差与输入侧电容电压的关系,继而提出一种间接电感均流控制方法,以此进行占空比的二次调节。在对单台电压平衡器分析的基础上,将基于二次调节的改进下垂控制应用于多台交错并联型电压平衡器并联协调控制中,实现了多台变流器间负载电流合理分配。最后在Simulink中验证了所提控制方法的正确性。     

Design and experimental validation of a high voltage ratio DC/DC converter for proton exchange membrane electrolyzer applications

This paper deals with hydrogen production via water electrolysis, which is considered the most attractive and promising solution. Specifically, the use of renewable energy sources, such as wind electric power generators, is hypothesized for supplying the electrolyzer, aiming to strongly reduce the environmental impact. In particular, micro-wind energy conversion systems (μWECSs) are attractive for their low cost and easy installation. In order to interface the μWECS and the electrolyzer, suitable power conditioning systems such as step-down DC-DC converters are mandatory. However, due to the requested high conversion ratio between the DC bus grid, i.e. the output of a three-phase diode rectifier connected to the output of the electric generator, and the rated supply voltage of the electrolyzer, the classic buck converter alone is not suitable. Therefore, a converter is proposed and designed, consisting of a buck converter, a full-bridge IGBT converter, a single-phase transformer, and a diode bridge rectifier; LC filters are also included between buck and full-bridge converters, and at the output of the diode bridge rectifier with the aim of reducing the ripple on currents and voltages. The components of the described physical system from the output of the three-phase rectifier up to the electrolyzer are then modeled assuming the transformer as ideal, and the model is employed for designing a PI-type controller. Experimental results are provided in order to demonstrate the effectiveness of the developed converter and its control for these applications.     

A stacked interleaved DC-DC buck converter for proton exchange membrane electrolyzer applications: Design and experimental validation

Since the two last decades, hydrogen production has been attracting the attention of the scientific community thanks to its inherent very low pollution when energy coming from renewable energy sources (RESs) are used. However, it implies the use of DC/DC converters to interface source and load. These conversion systems must meet several requirements from current ripple point of view, energy efficiency, and performance to preserve the sustainability of hydrogen production. This article proposes the design and realization of a stacked interleaved buck converter to supply a proton exchange membrane electrolyzer. The converter is designed to ensure a low output current ripple and a suitable dynamic response to guarantee the reliability of the electrolyzer. A theoretical analysis of the converter, taking into account the dynamic model of the electrolyzer, and the design of the control system based both on feedforward and a feedback action is provided. The stability of the control system is discussed as well. The effectiveness of the model and the control algorithm has been verified by simulation and experimental results on a PEM electrolyzer at laboratory scale; the extension to higher power levels is discussed at the end.     

Predicting efficiency of solar powered hydrogen generation using photovoltaic-electrolysis devices

Hydrogen fuel for fuel cell vehicles can be produced by using solar electric energy from photovoltaic (PV) modules for the electrolysis of water without emitting carbon dioxide or requiring fossil fuels. In the past, this renewable means of hydrogen production has suffered from low efficiency (2–6%), which increased the area of the PV array required and therefore, the cost of generating hydrogen. A comprehensive mathematical model was developed that can predict the efficiency of a PV-electrolyzer combination based on operating parameters including voltage, current, temperature, and gas output pressure. This model has been used to design optimized PV-electrolyzer systems with maximum solar energy to hydrogen efficiency. In this research, the electrical efficiency of the PV-electrolysis system was increased by matching the maximum power output and voltage of the photovoltaics to the operating voltage of a proton exchange membrane (PEM) electrolyzer, and optimizing the effects of electrolyzer operating current, and temperature. The operating temperature of the PV modules was also an important factor studied in this research to increase efficiency. The optimized PV-electrolysis system increased the hydrogen generation efficiency to 12.4% for a solar powered PV-PEM electrolyzer that could supply enough hydrogen to operate a fuel cell vehicle.     

PEM water electrolyzer model for a power-hardware-in-loop simulator

Power-electronics-based power-hardware-in-loop (PHIL) simulator for water electrolyzer emulation with a nominal current of 405 A is developed to study the electrolyzer as part of a smart grid and to analyze the characteristics of various electrolyzer power supply electronics. A simplified model of a proton exchange membrane (PEM) electrolyzer is implemented into the PHIL simulator to describe the voltage and current characteristics of the electrolyzer stack. The model is verified comparing the current and the estimated hydrogen production of the PHIL simulator with the measured values of the commercial PEM electrolyzer following the measured solar photovoltaic (PV) system output power.     

Experimental study on the external electrical thermal and dynamic power characteristics of alkaline water electrolyzer

As hydrogen production with a water electrolyzer is an effective way for renewable energy consumption, understanding the external electrical characteristics of water electrolyzer is of great significance for the modeling and simulation, system configuration, and control strategy of the system for hydrogen production by renewable energy. However, there are relatively fewer studies in this area. This paper presents the establishment of an experimental platform to conduct an experimental study on the static and dynamic voltage‐current characteristics and analyze the adjustability of the electric power of the traditional alkaline water electrolyzer, the relationship between the electrical characteristics and the electrolyte temperature, and operating point of the alkaline water electrolyzer. In addition, the mathematical fitting problem of the electrical characteristics of the alkaline water electrolyzer is discussed. The work could supply a reference to alkaline water electrolyzer intergrated application in renewable energy.     

Optimization of power allocation for wind-hydrogen system multi-stack PEM water electrolyzer considering degradation conditions

Hydrogen production from wind power has become one of the most important technologies for the large-scale comprehensive development and utilization of wind power, but the randomness of wind power has a large negative impact on the stability and cost of such wind-hydrogen hybrid energy systems. In this work, we initially analyze the relationship between electrolyzer efficiency and degradation with a three-dimensional multi-physics field model of PEMWE single-cell. Optimization of a power allocation strategy for wind-hydrogen system with a multi-stack PEM water electrolyzer (PEMWE) is proposed by considering degradation conditions. The multi-stack PEMWE power allocation strategy consists of the control module and execution module. In the control module, the degradation of PEMWE is quantified using the voltage degradation rate under different operating conditions. By setting the turning power point and external power supply and calculating the power allocation order online to reduce the degradation of PEMWE. In the execution module, the extended duty cycle interleaved buck converter (EDCIBC) based on fuzzy PID control is used to power each PEMWE single-stack. Case studies are carried out via computer simulation based on the configuration and experimental data for a specific wind farm located in Cixi, Zhejiang, China. Our results show that the energy efficiency of the wind-hydrogen system is 61.65% in a one-year operation, the voltage degradation of the PEMWE single-stack is 7.5 V, and the maximum efficiency is 6.29% lower than that when it is not aged. The EDCIBC output current ripple is as low as 0.053%, which rapidly and accurately follows the generated power allocation signal.     

预磁极化条件下PEM水电解制氢特性与效率研究

为提高质子交换膜（proton exchange membrane,PEM）水电解制氢速率、降低电解所需能耗,针对磁场预极化条件下蒸馏水的分子极性和应力特性进行研究,通过构建磁场环境下氢质子的能级跃迁微观物理模型与磁化矢量——极化氢质子浓度对应的宏观数学模型,对不同磁场强度下电解液的离子电导率、电流密度和制氢速率进行定性和定量分析,并利用自主搭建的可调节预磁极化PEM水电解制氢试验平台对所提出方法的有效性进行重复试验。试验结果表明,经过预磁极化处理的蒸馏水电导率提高了2~3倍,且随着磁场强度的增加,PEM电解电流密度不断增大,极间电圧不断减小,制氢速率明显提升。     

DC/DC converter topologies for electrolyzers: State-of-the-art and remaining key issues

In recent years, the use of electrolyzers to produce cleanly and efficiently hydrogen from renewable energy sources (i.e. wind turbines, photovoltaic) has taken advantage of a growing interest from researchers and industrial. Similarly to fuel cells, DC/DC converters are needed to interface the DC bus with the electrolyzer. Usually, electrolyzers require a low DC voltage to produce hydrogen from water. For this reason, a DC/DC buck converter is generally used for this purpose. However, other DC/DC converter topologies can be used depending on the feature of the electrolyzer and electrical grid as well. The main purpose of this paper is to present the current state-of-the-art of DC/DC converter topologies which can be combined with electrolyzers. The different DC/DC converter topologies are compared in terms of output current ripple reduction, conversion ratio, energy efficiency, and power switch fault-tolerance. Besides, remarks on the state-of-the-art and remaining key issues regarding DC/DC converters are provided.     

Wind-powered 250 kW electrolyzer for dynamic hydrogen production: A pilot study

Alkaline water electrolysis is the most promising approach for the industrial production of green hydrogen. This study investigates the dynamic operational characteristics of an industrial-scale alkaline electrolyzer with a rated hydrogen production of 50 m³/h. Strategies for system control and equipment improvement in dynamic-mode alkaline electrolytic hydrogen production are discussed. The electrolyzer can operate over a 30%–100% rated power load, thereby facilitating high-purity (>99.5%) H₂ production, competitive DC energy efficiency (4.01–4.51 kW h/Nm³ H₂, i.e., 73.1%–65.0% LHV), and good gas–liquid fluid balance. A safe H₂ content of 2% in O₂ (50% LFL) can be guaranteed by adjusting the system pressure. In transient operation, the electrolyzer can realize minute-level power and pressure modulation with high accuracy. The results confirm that the proposed alkaline electrolyzer can absorb highly fluctuating energy output from renewables because of its capability to operate in a dynamic mode.     

A new multi-mode fault-tolerant operation control strategy of multiphase stacked interleaved Buck converter for green hydrogen production

This paper presents a new fault-tolerant operation method of multiphase stacked interleaved Buck converter for green hydrogen production. An improved topology and new fault-tolerant control strategy is proposed. Multi-mode fault-tolerant operation of multiphase stacked interleaved Buck converter for different performance requirements of electrolyzer in hydrogen production system is realized. The multiphase stacked interleaved Buck converter can not only achieve elimination of output current ripple in normal operation mode, but also adopt different fault-tolerant modes according to different demands of electrolyzers in case of failure of any phase of converter. The proposed method is able to improve the availability of multiphase stacked interleaved Buck converter, reduce the times of equipment shutdown, and ensure the continuous operation of hydrogen production system from renewable energy sources. The effectiveness of the proposed method has been verified by experimental results.