direct torque control (DTC) of induction motor is known to have a simple control structure with comparable performance to that of the field-oriented control technique (FOC). But there are two major problems that are usually associated with DTC drives are: 1) switching frequency that varies with operating conditions and 2) high torque and flux ripples. To solve these problems, and at the same time retain the simple control structure of DTC, a constant switching frequency torque controller is proposed to replace the conventional hysteresis-based controller. In this paper, the simulation of proposed controller followed by experimental results is presented. The proposed controller is shown to be capable of reducing the torque and flux ripples and maintaining a constant switching frequency which gives a better dynamic performance than the conventional methods. |
