Study of Direct Torque Control Strategy Based on Regional Interpolation of Zero Voltage Vector in a Permanent Magnet Synchronous Motor

Direct Torque Control (DTC) is a new technique to obtain the higher control features in the AC machines. The torque ripple is the inherent features since the bang-bang control method is adopted in DTC system. In order to decrease the torque ripple in permanent magnet synchronous motor (PMSM) with the large capacity, the regional interpolation algorithm of zero voltage vectors is proposed and the practical selective strategy of voltage vectors is provided as well. The above algorithms are verified by the simulation studies with the real parameters of the large capacity electric propulsion ship. The simulation results prove that the proposed DTC strategy can effectively reduce the torque ripple. The application issues of the control strategy are also discussed in this paper.