摘要
随着可再生能源发电及电解制氢技术的发展,基于质子交换膜(PEM)技术的可再生能源制氢将成为氢能供应的主要手段之一。新能源发电具有随机性和波动性,现有多堆PEM电解制氢系统功率分配策略难以在功率波动场景下保证系统高效运行。对此,该文首先建立了包含主要能耗环节的制氢系统整体效率模型,探究了制氢效率与电流密度、温度的特性关系。然后,根据该效率特性提出了基于功率-温度自适应控制的多堆PEM电解制氢系统效率优化策略,包含离线优化与在线控制两部分:离线优化部分根据制氢系统效率模型预先制定不同电解总功率下的电解槽功率及温度设定方案;在线控制部分根据离线优化方案、制氢功率进行电解槽功率和温度调节。最后,采用实际风电功率进行算例分析,结果表明,相比于传统的功率平均分配策略和链式分配策略,该文提出的效率优化策略将产氢量分别提高了6.4%和5.7%。
With the growing focus of human society on low-carbon energy,the proportion of hydrogen energy in power systems is increasing and the hydrogen production system from water electrolysis is evolving towards a larger capacity and multiple stacks.Water electrolysis based on the proton exchange membrane(PEM)technology using renewable energy is a promising means of promoting the consumption of renewable energy and building a low-carbon power system.However,the randomness and volatility of renewable energy pose challenges to the efficient operation of a multi-stack PEM electrolytic hydrogen production system under fluctuating power scenarios.To enhance the efficiency of hydrogen production systems with multi-stack PEM electrolyzers,this research proposes an efficiency optimization strategy with power-temperature adaptive control.The research work is described as follows:Firstly,an overall efficiency model of the hydrogen production system is established.The relationship between optimal system efficiency and the electrolytic power and temperature is analyzed.It reveals that the optimal electrolytic efficiency might not be achieved at the upper limits of electrolytic temperature.When the current density is low,the optimal electrolytic temperature is relatively low due to the significant reduction in Faraday efficiency caused by temperature rise.However,when the current density exceeds 1.5 A/cm2,the optimal electrolysis temperature increases with the increase of current density.Therefore,to improve the electrolytic efficiency when the power of renewable energy fluctuates,it is necessary to properly adjust the electrolytic power and temperature of the electrolyzers.Secondly,offline optimization and online control are employed to enhance electrolytic efficiency.The offline optimization involves a two-stage optimization model,where the first stage optimizes the startup and shutdown status,electrolysis power,and temperature settings of different electrolyzers to maximize hydrogen production efficiency.In the second stage,a specific power-temperature implementation scheme is determined for the electrolyzers,to achieve rapid temperature adjustment when there are multiple solutions in the first stage.In the online control section,the dynamic models of the power and temperature control of the electrolyzers are established,respectively.Based on the current total power of hydrogen production and the power-temperature setting scheme determined in the offline optimization stage,the PWM modulation signal and the valve opening signal are generated by the buck and the valve controllers,respectively.Finally,to verify the effectiveness of the proposed efficiency enhancement strategy,a comparison is made between the proposed method and the existing average allocation strategy and chain allocation strategy.The analysis shows that the efficiency of hydrogen production is affected by both electrolytic power and temperature.Increasing the electrolysis temperature does not necessarily improve the hydrogen production efficiency,and its optimal value should be determined based on the electrolysis power.Compared with the average allocation strategy and the chain allocation strategy,the power-temperature adaptive control strategy proposed in this research can make full use of low renewable energy efficiently,while maintaining high efficiency over a large power range,making it suitable for hydrogen production with power fluctuations.In actual scenarios of hydrogen production from wind power,the proposed power-temperature adaptive control strategy can increase hydrogen production by 6.4%and 5.7%,respectively,compared with the average allocation strategy and chain allocation strategy.
作者
韩鹏飞
徐潇源
王晗
严正
Han Pengfei;Xu Xiaoyuan;Wang Han;Yan Zheng(Key Laboratory of Control of Power Transmission and Conversion Shanghai Jiao Tong University,Shanghai 200240 China;Shanghai Non-Carbon Energy Conversion and Utilization Institute,Shanghai 200240 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2024年第7期2236-2248,共13页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(52077136,U2166201)。
关键词
质子交换膜电解槽
电解制氢
新能源发电
效率优化
自适应控制
Proton exchange membrane elecrolyzers
power to hydrogen
renewable energy power generation
efficiency optimization
adaptive control
