Control of plant with dynamics asymmetry caused by the actuator rate saturation change

The controller for plants with dynamics asymmetry caused by the actuator rate saturation change has been suggested and analyzed. The control algorithm used in the proposed controller is modification of the PI control method. The characteristic property of the algorithm is that the value of integral constant of the controller is changed when the sign of the plant output parameter time derivative changes. This feature enables improving the response of the control system. The results of the investigation of the unit feedback control system of the plant with dynamics asymmetry caused by the actuator rate saturation change based on the proposed controller are presented. The investigation was performed using the software Simulink. The proposed controller was employed for control of differential air pressure in the industrial ventilation system with a variable speed drive of fan based on the AC induction motor supplied by the frequency converter, which acts as the actuator with the rate saturation. The results of experimental investigation of the ventilation system prove the superiority of the suggested controller over the PI controller in situation when different values of the fan drive motor acceleration and deceleration are used.