| Abstract |
A brief review of the classical Direct Torque Control (c_DTC) in induction motors with
its fundamental principles and schemas is realised. Once the c_DTC is fully and deeply
described, its main drawbacks are introduced. It is one of the goals of the present paper
to overcome one of the worst disadvantages of the DTC, which is the existence of a
considerable ripple in its torque response. The reduction in the torque ripple is achieved
by means of a two state modulator. Due to the fact that the torque ripple reduction
involve non-linear functions, the two state modulator is controlled by means of a fuzzy logic
controller. Then, a novel Fuzzy Logic DTC controller, which is based on the classical c_DTC but
includes a Fuzzy Logic Controlled modulator, is fully described.
Finally, an optimised way of calculating the stator reference flux value is presented, which can be
applied in any kind of induction motor drive. This optimised stator flux reference value not only
improves the torque ripple, but also could reduce the power consumption taken from the mains supply.
Results are shown to corroborate all the presented work. |
