Bus-clamping-based switch vector table of DTC

This paper proposes a new type of switch vector table based on bus-clamping of DTC for induction motor drives. This strategy will combine look-up table method of Takahashi DTC with bus-clamping technology, then, a new bus-clamping DTC (BCDTC) switch vector table will be gained. BCDTC is consistent with the traditional DTC strategy, depends on monitoring and control the stator flux vector Φ̅_s, tracking its trajectory for a circular to achieve direct torque control requirement. As introduced bus-clamping technology, BCDTC strategy leads to keep each inverter phase conduction on or off during 60° interval in every half cycle of the stator flux vector. As BCDTC strategy is not based on fixed modulation time, so a quick response system is obtained, and bus-clamping technique makes the inverter switch frequency reduced, resulting to the torque ripple reduced.