A novel direct torque control of PMSM based on three-phase H-bridge inverter

To increase power and improve performance of the inverter, a topology of three-phase H-bridge inverter is proposed in this paper, the voltage vectors of the three-phase H-bridge inverter are defined and computed, and the distribution of those voltage vectors is analyzed. In terms of the vector distribution, the influence of every voltage vector on flux-linkage and torque is analyzed, and an optimal switching table based on seven-grade hysteresis control of torque and two-grad hysteresis control of flux-linkage is proposed. Based on the optimal switching table, the direct torque control of permanent magnet synchronous motor with less switching loss and lower torque pulsation is presented. The software MATLAB and an experiment system are used to simulate and test the presented control. The wave of flux-linkage, torque and speed are obtained and analyzed.