A Hybrid Fuzzy Logic controller for direct torque controlled induction motor

Generally in speed control loop PI controller is used in order to obtain closed loop control performance for the drive. When the load is suddenly applied on the machine under steady state operating condition of the machine, there is sudden dip in the speed. If the load is high then this dip may be large. Conventional PI controller can´t eliminate the dip in the speed. In this paper, to reduce the dip in the speed, New Hybrid Fuzzy controller for DTC of Induction Motor Drive has been developed. The developed Hybrid Fuzzy controller consists of Proportional-Integral (PI) control for the steady state, PI-type Fuzzy Logic Control at transient state, and a simple switching mechanism between steady and transient states, to achieve satisfactory performance under steady and transient conditions for DTC-based induction motor drives and results are presented to show the effectiveness of the proposed control scheme.