| Abstract: | To improve the robustness and performance of the dynamic response of a cage asynchronous motor, a direct
torque control (DTC) based on sliding mode control (SMC) is adopted to replace traditional proportional-integral
(PI) and hysteresis comparators. The combination of the proposed strategy with sinusoidal pulse width modulation
(SPWM) applied to a three-level neutral point clamped (NPC) inverter brings many advantages such as a reduction
in harmonics, and precise and rapid tracking of the references. Simulations are performed for a three-level inverter
with SM-DTC, a two-level inverter with SM-DTC and the three-level inverter with PI-DTC-SPWM. The results show
that the SM-DTC method achieves better performance in terms of reference tracking, while adoption of the threelevel
inverter topology can effectively reduce the ripples. Applying the SM-DTC to the three-level inverter presents
the best solution for achieving efficient and robust control. In addition, the use of a sliding mode speed estimator
eliminates the mechanical sensor and this increases the reliability of the system. |
