Model predictive direct torque control of a three-phase four-switch inverter induction motor driving system

With the development of power electronics and motor driving system, AC motor speed control or the servo system has been widely explored. Among them, the Induction Motor (IM) driving based on a three-phase six-switch inverter has become a mature technology for a wide range of applications. However, in some scenarios, a certain fault-tolerant ability and further cost savings are required. Under this circumstance, the motor driving system based on the three-phase four-switch inverter is proposed. However, it has fewer voltage vectors, with unequal amplitudes, spatial asymmetry, and no zero vector, which will inevitably lead to the deterioration of the control performance. In this study, the operation of the four-switch inverter IM driving is analysed in detail. The model predictive direct torque control (MPDTC) is proposed to obtain better static and dynamic characteristics. Through the simulation and experimental studies, the control algorithm is verified to drive a 2.2 kW IM. Compared with the conventional DTC, the proposed MPDTC has a rapid dynamic response and greatly reduces the torque and flux ripple in a steady state.