Direct torque control of three phase induction motor using fuzzy logic speed controller for steady / dynamic state response 1

This paper presents a Space Vector-PWM based DTC control of the three-phase Induction Motor using a fuzzy logic controller (FLC) for good speed regulation and lower electromagnetic torque ripples. Induction Motor has a three phase winding with the operating frequency of 50/60Hz and the operating voltage of 230VAC. DTC is achieved by comparing the motor actual torque and operating flux with the motor reference electromagnetic torque and flux values directly. Conventional DTC method uses the static PI controller in a speed regulation loop to generate the flux reference and torque reference values. The main drawback of the conventional DTC is high stator flux and electromagnetic torque ripples and the speed of Induction motor is reducing under transient and dynamic state of operating condition. These drawbacks were reduced in proposed DTC method. In proposed method, the static PI controller is replaced by the Fuzzy Logic Controller. Fuzzy logic speed controller generates the torque reference value and flux reference value based on the speed error. Simulation results show that the proposed DTC method gives the better performance in the Induction Motor than conventional DTC methods.