All-Switching-Patterns Search Considering Voltage Integral Trajectory for Low-Switching-Frequency Motor Drive and Its Application

This study focuses on the voltage-integral trajectory of a low-switching-frequency motor drive and proposes a method for optimizing switching patterns. The voltage-integral trajectory is computed to minimize the inverter switching frequency. The optimal solution is uniquely determined by all-switching-patterns search. The optimized trajectory has significant performance advantages under steady-state conditions. Additionally, by integrating it into direct torque control as an application of closed-loop control, high-speed response and superior steady-state characteristics can be achieved. To highlight the effectiveness of the proposed strategy, the performance is evaluated experimentally using a system consisting of an induction machine and a two-level three-phase inverter.