A Three-Level Fuzzy-2 DTC of Induction Motor Drive Using SVPWM

This paper presents proportional integral direct torque control (PIDTC) and fuzzy-2 DTC (F2DTC) of the induction motor (IM) drive using space vector pulse width modulation (SVPWM) for three-level diode-clamped inverter (TDCI). The above control schemes have been implemented in the laboratory using 2 HP IM through a DSPACE DS-1104 controller. The control schemes are capable to balance the dc-link capacitor voltages of TDCI by selecting an optimum voltage vector without using an extra controller. However, the three-level PIDTC of an IM gives poor transient performance during starting, loading, and speed reversal with considerable current and voltage total harmonic distortion (THD). In addition, it takes more time to reach the steady state with large spikes on capacitor voltages during the load or speed variation. This is due to poor performance of the PI controllers (speed and torque). In F2DTC, the conventional PI controllers are replaced by Mamdani-type fuzzy-2 controllers using a centroid method with simple logical rules. The simulated and experimental performance show that F2DTC for the three-level inverter-fed IM drive provides a fast dynamic response, less current and voltage THDs, considerable less distortion in flux and torque, and fewer spikes on capacitor voltages as compared to PIDTC.