Novel design of a Takagi-Sugeno fuzzy strategy for induction motor speed control

This paper presents a novel design of a Takagi-Sugeno fuzzy logic control scheme for controlling some of the parameters, such as speed, torque, flux, voltage, current, etc. of the induction motor. Induction motors are characterized by highly non-linear, complex and time-varying dynamics and inaccessibility of some of the states and outputs for measurements and hence it can be considered as a challenging engineering problem. The development of advanced control techniques has partially solved some of the induction motor's speed control problems; because they were sensitive to drive parameter variations and the performance may deteriorate if conventional controllers are used. Fuzzy logic based controllers are considered as potential candidates for such an application. Further, the Takagi- Sugeno control strategy coupled with fuzzy logic rule based approach when employed to the induction motor yields excellent results compared to the other methods as this becomes a hybrid & integrated method of approach. Such a mixed implementation leads to a more effective control design with improved system performance, cost-effectiveness, efficiency, dynamism, reliability & robustness. Due to the usage of the TS-FLC concept in closed loop with the plant, the dynamic characteristics of the AC drives increases as the developed strategy does not require the mathematical model of the controller unlike that of the conventional electrical drive controller, which uses the mathematical model, which is the highlight of the paper. The sudden fluctuation or change in speed & its effect on the various parameters of the dynamic system is also considered in this paper. The designed controller not only takes care of the sudden perturbations in load torque & speed, but also brings back the parameters to the reference or the set value in fraction of seconds, thus exhibiting the robustness behavior. In other sense, the designed controller is robust to parametric variations. The closed loop speed control of the induction motor using the above technique thus provides a reasonable degree of accuracy which can be observed from the simulation results depicted at the end. Simulink based block model of induction motor drive was developed & used for the simulation purposes. Further, its performance is thereby evaluated for the control of various parameters. The method presented in this paper provides robustness of the induction machine towards the parametric variations compared to the conventional speed control of induction motor drives & has got a faster response time or settling times. The simulation results presented in this paper show the effectiveness of the method developed & have got a wide number of advantages in the industrial sector & can be converted into a real time application using some interfacing cards.