Vector control of permanent magnet synchronous motor drive using a reduced switch five-level inverter

Abstract

This paper presents one of the most popular closed-loop control techniques namely the Vector Control for the control of a Permanent Magnet Synchronous Motor (PMSM) drive using a reduced switch five-level inverter. A SIMULINK model for the vector control of a surface mounted PMSM drive system is implemented using two different inverters, namely, a conventional sinusoidal pulse width modulated (SPWM) two-level voltage source inverter (VSI) and a reduced switch five-level PWM VSI. A comparative performance analysis of the two topologies is presented, for various dynamic operating conditions like load torque perturbations and different reference speed conditions, keeping the DC link voltage and carrier frequency the same for both topologies. The simulation results of the proposed drive system using a reduced switch five-level inverter validate the relevance of the rising popularity of multilevel inverters for adjustable speed drive applications and also emphasize the fact that a five-level inverter offers an advantageous choice of working with lower switching frequencies, maintaining a low and consistent value of current THD, thereby reducing switching losses, unlike SPWM technique for the two-level VSI which needs to be implemented at higher switching frequencies in order to maintain a low value of current THD.