基于120 kW燃料电池空气系统试验的流量和压力协调控制

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

摘要:

大功率质子交换膜燃料电池的空气子系统通过控制空压机转速和背压阀开度来调整进气流量和压力。由于该多变量系统具有非线性与耦合性特性，因此导致参数控制困难。研究采用前馈控制与双回路PI控制相结合的策略来调节该系统的进气流量和压力，该控制方法涉及的参数少。在采用该控制方法的试验过程中，根据电堆操作条件对空气子系统流量和压力的需求在线标定控制参数，得到前馈表和PI参数。试验结果表明：采用前馈控制与双回路PI控制相结合的控制策略，可使空气子系统实际流量与设定流量误差控制在1.5 g/s以内，际压力与设定压力误差控制在0.25 kPa以内。该控制策略和控制参数确定方法可以实现大功率质子交换膜燃料电池空气子系统流量和压力的解耦控制，可满足燃料电池系统空气供气要求。

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.