Transient State Control Of Aero-engine Based On Active Disturbance Rejection Control

The aero-engine is a kind of complex nonlinear systems operating in a broad flight envelope,and thus it is difficult to design an effective control system to guarantee the engine to operate safely while simultaneously achieving the desired performance.The aero-engine transition state control plays an important role in the design of the aero-engine control system.The traditional transition state control based on the fuel ratio unit control makes the transition state control less flexible due to its open-loop properties.The acceleration / deceleration process runs according to the design schedule in advance,and the transition time can not be arranged according to the specific flight task,so that the life of the hot end parts is affected.In addition,during the switching process between the steady-state controller and the acceleration / deceleration schedule,there often exists the integral saturation.Therefore,a technique called active disturbance rejection control is proposed to realize the acceleration / deceleration process of aero-engine in a more flexible manner.According to the requirements of response time for acceleration / deceleration state,tracking differentiator is utilized to arrange the expected transition trajectories.An extended nonlinear state observer is introduced to estimate the rotor speed and its acceleration,as well as system disturbances.Based on this,a nonlinear PD controller is designed and added to the active disturbance rejection control algorithm,thus avoiding the integral saturation phenomenon.In addition,in order to ensure system safety and reliability,limit regulators are constructed with acceleration/deceleration schedule and values at steady state.Finally,comparisons between the proposed method and the traditional linear PI controller are conducted based on nonlinear model to show the effectiveness and flexibility of the proposed strategy.It is seen that the ADRC method can reduce the overshoot of turbine temperature and then extend its lifetime if fast response speed is not pursued.