Direct torque control with the application of a predictive pulse width control

The direct torque control (DTC) method selects the most suitable stator voltage space vector on the basis of the actual flux and torque values with respect to their reference values. In a digital control system, this voltage space vector will be applied for the whole sampling period, and therefore the stator flux could cross its boundary too far. In order to avoid this problem, the proposed method calculates on the hand of the stator equation the pulse width of the voltage space vector, which is exactly needed to reach the flux boundary. The predictive pulse width control (DTC-PPWC) scheme can be considered as a simple extension of the classic DTC algorithm and has been validated by simulations and experiments, showing excellent results. Furthermore, the advantages of the DTC, i.e. low switching losses and its simple implementation, are only slightly violated.