Feedforward and Desired Dynamic Equation Control for Solid Oxide Fuel Cell System

Abstract

The solid oxide fuel cell (SOFC) system, with almost no pollution, low noise and high efficiency, is playing a more and more significant role in power supply. However, the regulation of output voltage and desired range of the fuel utilization, caused by its strong nonlinearity, system uncertainty and ever-changing external current load, are challengeable. To relieve these challenges, this paper proposes a hybrid control scheme combing the physical feedforward and desired dynamic equation (DDE) control. By analyzing these control challenges theoretically, a physical feedforward is applied to accelerate the system response and keep the fuel utilization in the desired range, and DDE control is proposed to handle system nonlinearity, uncertainty and external disturbances. Then a practical and effective tuning method for the DDE parameters is provided. Finally, the proposed and comparative control strategies are applied to the SOFC system. Simulation results show that the proposed control scheme has the strongest ability to reject the external current load and handle system uncertainties. Besides, it can guarantee that fuel utilization always locates in a reasonable range.