Volume 6: Innovative Solutions for Energy Transitions: Part V

Research on Power Optimization Control of Solid Oxide Fuel Cell/Lithium Battery Hybrid System Xiaobo Zhong, Zehua Li, Xiaolong Wu, Yuanwu Xu, Dongqi Zhao, Jianhua Jiang, Zhonghua Deng, Xiaowei Fu, Xi Li*

Abstract

Solid Oxide Fuel Cell (SOFC) has great scientific significance and market space as a green energy industry. The SOFC power generation system has the characteristics of slow dynamic response of the output power, so the lithium battery is used as an auxiliary power source to cooperate with the SOFC for power generation. In this paper, the 500W pure hydrogen solid oxide fuel cell system is modeled first. Then, the lithium battery state space model is built, and the second-order RC circuit equivalent model is selected to build the SOC estimation model and the SOH estimation model respectively. The Particle Filter (PF) algorithm is used to realize the joint estimation of SOC and SOH of lithium battery. Finally, the T-S fuzzy controller is designed for energy control. By controlling the output current of the lithium battery, the SOC is within a reasonable range in the process of coordinated power generation. In order to simulate the working condition of the hybrid energy system and test the feasibility of the control algorithm, this paper uses dSPACE to build a semi-physical simulation platform, and downloads the control algorithm to the control board to combine with the system model and electrical equipment for online simulation. The validity of the test algorithm is verified by the irregular load power variation, the problem of slow response of SOFC power tracking is solved, and the protection of lithium battery SOC is realized.

Keywords SOFC, joint estimation of SOC and SOH, T-S fuzzy control, semi-physical simulation