Zero Common Mode Voltage Direct Torque Control of TLDMC-PMSM Based on Dynamic Switching Table
Aiming at the problem of high common-mode voltage when direct torque control(TLDMC-PMSM-DTC)is adopted in permanent magnet synchronous motor system of three-level direct matrix converter,a zero common-mode voltage direct torque control method based on dynamic switch table is proposed.Because the common mode voltage of the rotation vector of TLDMC is zero,this method uses the rotation vector to construct the switch table of DTC,but because the distribution of the rotation vector changes with the phase of the input voltage,which will lead to the complexity of the control structure,this control algorithm provides a high-dimensional switch table to realize the zero common mode voltage of TLDMC-PMSM.However,because the number of rotation vectors used is small and the error of selection vector is large,the speed and torque pulsation of the motor are large,so on this basis,dynamic rotation vectors and zero vectors are introduced to construct a dynamic switch table to solve the problem of large pulsation.The simulation and experimental results show that this method realizes zero common mode voltage and safe and stable operation of TLDMC-PMSM system on the basis of ensuring fast dynamic response and small motor speed and torque ripple.
three-level direct matrix converterpermanent magnet synchronous motordirect torque controlrotation vectorzero common mode voltagedynamic switch table