Space vector modulation direct torque control of high speed permanent magnet synchronous motor based on five-level inverter

Abstract

Due to the unique electromagnetic design of high-speed Permanent Magnet Synchronous Motor (HPMSM), the stator inductance value is small, which will cause problems such as stator current harmonics and excessive torque ripple in operation. Multilevel inverter can produce more levels and make the output voltage of inverter closer to sine wave. Direct Torque Control (DTC) has the advantages of simple algorithm and fast response, and is widely used in the control system of high-speed PMSM. However, multilevel inverters have many vectors and complex algorithms. Therefore, this paper proposes a simplified five-level Space Vector Pulse Width Modulation (SVPWM) algorithm and applies it to Space Vector Modulated Direct Torque Control (SVM-DTC). The proposed SVM-DTC strategy based on simplified five-level SVPWM can effectively reduce the calculation amount and reduce the harmonic content of stator current and torque ripple, so that the motor drive has good steady state and dynamic performance. The proposed method is simulated in MATLAB/SIMULINK software, and compared and analyzed with the three-level SVM-DTC system. This method can inhibit the harmonic content of stator current and torque ripple obviously.