Study on Air Pressure-Flow Decoupling Control in Fuel Cell System Based on Feedforward Algorithm 2019-01-5042

Proton exchange membrane fuel cell (PEMFC) system is considered to be one of the ideal replacement for conventional Internal Combustion Engines (ICE) due to its zero emission, low operating temperature and high power density. The high-pressure PEMFC system has become the future development direction because the higher gas pressure can effectively improve the performance and power density of stack. However, the high gas pressure can lead to the damage of membrane electrode assembly (MEA) and even the failure of fuel cell stack.

As the air supply system is a nonlinear system, the flow and pressure have a strong coupling relation. For this problem, firstly, the mathematical model of air supply system is established in MATLAB/Simulink. Then a dual-loop control strategy is used in controller. The static feedforward decoupling algorithm of air pressure-flow and the air pressure closed loop control algorithm are used as external control loops to determine the control objectives of the two actuators: BPV position and air compressor speed. The BPV position closed-loop control algorithm is used as the inner control loop to realize the control target determined by the outer control loop algorithm. The external loop control algorithm is simulated on the aforementioned model to verify the feasibility of the algorithm. According to the MATLAB/Simulink simulation and test bench result, the gas pressure and flow of the air supply system can be well controlled.