Design of Robust Speed Controller by Optimization Techniques for DTC IM Drive

Direct Torque Control (DTC) of induction motor is preferred control strategy recently, due to its quick torque response, simplicity, less sensitivity against motor parameter variation. In general, PI speed controllers are widely used in industrial applications due to their simple structure. Due to the continuous variation of machine parameters, model uncertainties, nonlinear dynamics and system external disturbance, fixed gain PI controllers may becomes unable to provide the required control performance. Genetic Algorithm (GA) is used to tune the PI controller gains to ensure optimal performance. GA is more attractive for applications that involve non smooth or noisy signals. GA is used to minimize speed error and attains optimal values of the PI controller gains. The efficient and effective speed controllers can be designed by using adaptive control techniques. In which the conventional PI controller is replaced by structures based on Sliding Mode Control (SMC) strategy. SMC is known for its capability to cope with bounded disturbance as well as model imprecision which makes it ideal for the robust nonlinear control of IM drives.