Feedforward-feedback composite control for aero engine air starting system

LEI Yong, LI Hui, SHI Xiaojiang
（The Gas Turbo Establishment of China, Jiangyou 621703, China）

Abstract: Aiming at the air starting system for starting aero engine had a steady step disturbance in the test, it caused the aero engine to arrive the ignition rotational speed time to grow, thereby the aero engine started failure, but the general PID feedback controller could not eliminate the disturbance, a method was presented to feedforward compensation. First, the transfer function of the object and disturbance was obtained by the means of system identify. Then, according to their model, a dynamic feedforward compensation controller was designed, it and PID feedback controller composed the composite controller. The actual use result indicate that the feedforwardfeedback composite controller makes the rising time of the inlet pressure to decrease 6 s, it greatly improves the system features to resist disturbances, and ensures the engine starting smoothly.
Key words: step disturbance; system identify; dynamic feedforward compensation; composite controller