Direct torque control system for induction motors with fuzzy speed PI regulator

Traditional direct torque control system of induction motor introduces conventional PI regulator in speed loop, it is proved that the low precision of the speed regulator debases the performance of the whole system. This paper establishes a fuzzy speed PI regulator, which applies the principles and method of fuzzy logic to adjust the proportional coefficient k _p and integral coefficient k ₁ of the PI regulator on-line, and finally get the system to adapt to different speed variations. The proposed method is implemented with a single board microcomputer that uses TMS320LF2407A DSP. The experimental results show that the fuzzy speed regulator can ensure swift speed response, small overshooting, and high steady speed precision both in high and low speed. Additionally, the proposed regulator improves the observation precision of the stator flux and enhances the robustness of the whole system.