Increasing the efficiency of motor-pump systems using a vector controlled drive for PMSM application

In this paper two operating modes available for permanent magnet synchronous machines (PMSM) are presented. This study aims to increase the efficiency of the motor-pump system. The PMSM is driven at variable speed and the inverter is controlled by space vector modulation theory. This study allows changing the component that produces magnetic flux (i_d), while the torque current component of PMSM (i_q) does not change. Reducing the magnetizing current will increase the stator winding flux linkages. The results show that for the same efficiency (when i_d is different to zero), the speed increases.