Coordinated Control of Flow Rate and Pressure Based on an Experiment in a 120 kW Fuel Cell Air System

Abstract:

The flow rate and back-pressure of the air supply system in the high-power proton exchange membrane fuel cell （PEMFC） are regulated by adjusting the speed of the air compressor and the angle of the solenoid valve， respectively. Due to the nonlinearity and coupling of the multivariable system， the control method and control parameters of the fuel cell system are complicated. For this reason， a strategy combining feedforward and double loop PI is designed to control the flow rate and back-pressure. The speed of the compressor and the angle of the back-pressure valve are matched by calibrating the feedforward table and PI parameters. The results show that the flow rate and back-pressure follow the set value， the flow error is within 1.5 g/s， and the pressure error is within 0.25 kPa. The proposed strategy can coordinately control the airflow rate and back-pressure， and meets the requirements of PEMFC.