Improved DSVM-DTC based current sensorless permanent magnet synchronous motor drive

Abstract

This paper presents the current sensorless control of a direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drive using an improved discrete space vector modulation (DSVM) technique. After considering the primary ideas of the DSVM-DTC technique, a new set of voltage vectors are synthesized in optimized sequence by applying three standard voltage space vectors for three equal time intervals at each sampling period for the realization of the DSVM-DTC methodology of PMSM drive which further reduces torque ripple. However, it addresses the problem by introducing a higher number of predefined voltage space vectors. The current estimation is based on discrete electrical motor model in rotor reference frame. Such sensor elimination results in reduction in drive cost, size, noise immunity, increases drive efficiency and reliability. The effectiveness of the proposed drive system is demonstrated and clarified by several drive tests in MATLAB/SIMULINK platform under loads perturbation and speed reversal dynamics incorporating constant power operation.