Date of Publication :14th April 2017

Abstract: Grain drying is process of drying grain to prevent spoilage during storage and its process has the characteristics of large time delay, nonlinearity, multi disturbance and strong coupling.The Direct Torque Control (DTC) is the fastest responding method in the vector control family in the induction motor control. The torque and the flux estimation is observed directly from the voltage and the current observed from the winding unlike getting the speed and then finding the desired flux and torque.In the actual control process of grain drying, the speed of the discharging motor is controlled to realize the drying target by detecting the outlet grain moisture. In order to reduce the grain moisture content during Continuous flow drying process, to ensure the grain quality of the grain, and enable the uniform moisture content of outlet grain, to control the speed of grain flow, a new improved controller model for grain drying which called the self-adjusting fuzzy controller is proposed and the problem of fixed change rate of the parameters of general PID controller is solved. This Project implements the direct torque control on the Induction motor with low ripples and fast torque dynamics. The flux estimation, torque estimation and the speed control technique for switching the Induction motor is the prime portion of the control system which is taken care by the self-adapting fuzzy controller based system. MATLAB based simulation is carried and compared for the dynamic response and the reduced torque ripples with PI controller.

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