PUBLICATIONS

This paper proposes the direct torque control (DTC) of interior permanent magnet synchronous motors (IPMSMs) for fast dynamic response with 

constant switching frequency. The conventional DTC is constructed based on the hysteresis flux and torque controllers with the flux and torque 

errors as input. The switching frequency of DTC is not constant. In the DTC with constant switching frequency, a torque regulator with a constant 

switching frequency is applied to overcome this problem, instead of the hysteresis torque controller for the conventional DTC. The DTC with 

constant switching frequency uses a torque regulator with a proportional-integral (PI) torque controller and a triangular carrier to realize a constant 

switching frequency. Compared to the conventional DTC, the DTC with constant switching frequency has the poor dynamic response because 

both voltage vectors increasing and decreasing torque are selected in the transient state. In this paper, the bandwidth of PI torque controller is 

varied to improve the dynamic response of the DTC with constant switching frequency. The effectiveness of the proposed method is verified 

through simulation results.