Modeling and Control for Alkaline Water Electrolyzers Operating in Wide Range
Haoran Cheng, Yanghong Xia, Zhiyuan Hu, Jia Xiong, Wei Wei
Abstract
Alkaline water electrolysis is one of the most promising solutions for large-scale hydrogen production from renewable energy sources (RESs) due to its low cost and maturity. However, the low-load performance of alkaline water electrolyzers (AWEs) is poor, which makes it difficult to follow fluctuant RESs in wide operating range. To address this problem, a novel equivalent circuit model of industrial AWESs is established based on its internal structure and operating principle. Then, a multimodal self-optimization control method and its prototype electrolysis converter are proposed to improve the efficiency of hydrogen production in low load. Compared with traditional methods, the proposed method can provide stable pulse current for the electrolyzer to realize efficiency improvement in low load. Finally, based on a 10 KW AWEs experimental platform, the correctness of the theoretical analysis is verified. The experimental results show that the proposed control strategy has a significant effect on the efficiency improvement of the 10 KW AWEs in low load.