Net Power Enhancement of PEMFC System Based on Dual Loop Multivariable Coordinated Management

A dual loop multivariable coordinated management (DLMCM) is proposed in this article dealing with the existed nonlinearity and strong coupling between operating parameters such as stack temperature and oxygen excess ratio, to achieve net power enhancement of proton exchange membrane fuel cell (PEMFC) system. The proposed optimization method includes: 1) outer net power optimization loop and 2) inner data-driven multivariable control loop. In solving the outer net power optimization, the experimental data based net power smooth surface model and the security constraints are proposed for maximum net power regulator design. Regarding inner data-driven multivariable control loop, first, pseudopartial derivative linearization (PPDL) is proposed for online modeling and estimation of the multi-input and multi-output system. Then, PPDL-based discrete adaptive integral terminal sliding mode control is proposed to achieve maximum net power trajectory tracking. Experimental tests carried out on 5-kW PEMFC system show that the proposed DLMCM has better tracking ability, and internal disturbance rejection compared with sliding mode control. Moreover, the comparative study with manual guided control, temperature control, and air flow control testifies the effectiveness of proposed DLMCM for net power enhancement with a low level of parasitic power consumption ratio.