无人机用燃料电池阴极供气系统建模与控制

Fuel cells are considered to be the most potential power source for Unmanned Aerial Vehicles (UAVs) in the future due to their high efficiency, non-pollution, low noise, and other characteristics. The control technology of the cathode gas supply system of the fuel cell is the key technology to determine the performance and reliability of the fuel cell system. For the air supply system of the Proton Exchange Membrane Fuel Cell (PEMFC) for UAVs, the parameters that vary with altitude, such as the outside temperature, pressure, air density, and Reynolds number, are firstly analyzed. A cross-height centrifugal air compressor model is established and its working characteristics at different altitudes are analyzed. Based on the back electromotive force characteristics of the brushless DC motor, we build a drive motor model of the high-speed air compressor. Secondly, the output voltage of the PEMFC stack is obtained by calculating the dynamic partial pressure of oxygen and nitrogen in the cathode of the fuel cell. The oxygen excess ratio and cathode air pressure control methods based on fractional order PI^λD^μ are designed. The drive motor adopts finite set Model Predictive Control (MPC) to achieve fast torque response. The simulation results show that the designed controller can realize rapid adjustment of the oxygen excess ratio under the operating conditions of the UAV across the altitude, while maintaining the cathode pressure stability and meeting the fuel cell cathode gas supply requirements.