Enhancement of rotor speed of a PMSM through Fuzzy logic controller based flux weakening

Permanent Magnet Synchronous Motor Drives are taking up the position of Induction Motor drives because of their numerous advantages like High Torque to current ratio, Low inertia, very high speed (30,000rpm), high efficiency etc. The field of PMSM is constant as the rotor used is permanent Magnet. Also, the speed of motor depends upon the flux which is constant, because of which the speed is also constant. Hence, if speed beyond the base speed is required the flux is to be reduced which in other words means the weakening of flux or field. The stator current is fully responsible for the “ARMATURE REACTION EFFECT”. Particularly, the Ids Component of IS is responsible for this. In this paper, to achieve the flux weakening, the Fuzzy logic controller (FLC) is used. The membership functions for flux (proportional to ids), the input to the FLC and the speed, the output of the FLC are framed using the known concepts and the drive is run. It is observed that the speed of the PMSM is enhanced through the flux weakening. MATLAB/SIMULINK is used for simulation and the results obtained are shown and the inferences are made.