说明：  Direct torque control (DTC) has been employed to give fast torque response, which is very important in traction and electric vehicle applications, in high dynamic performance Induction Motor (IM) drives. Fast torque response can be achieved by optimizing the selection of the inverter voltage vectors in the conventional DTC. This paper introduces a method for selecting voltage vectors; in DTC controlled IM drives, to achieve fast torque response at constant switching frequency.