无人机用燃料电池阴极供气系统建模与控制

燃料电池因其高效、无污染、噪声小等特点，被认为是未来最具有潜力的无人机（UAV）用动力源，燃料电池阴极供气系统的控制技术是决定燃料电池系统性能和可靠性的关键。针对无人机用质子交换膜燃料电池（PEMFC）阴极供气系统，首先，考虑外界温度、压力、空气密度以及雷诺数等随高度变化的参数，建立了跨高度离心空压机模型并分析了其在不同高度下的工作特性，基于无刷直流电机反电势特征构建了高速空压机驱动电机模型。其次，通过计算燃料电池阴极氧气和氮气的动态分压获取了PEMFC电堆输出电压。设计了基于分数阶PI^λD^μ的过氧比和阴极气压控制方法，驱动电机采用有限集模型预测控制（MPC）实现快速的转矩响应，仿真结果表明设计的控制器可在无人机跨高度运行条件下实现过氧比的快速调节，同时维持阴极气压稳定，满足燃料电池阴极供气需求。

Modeling and control of fuel cell cathode gas supply system for UAV

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.