Fuzzy logic based speed and current control of vector controlled PMSM drive

Abstract

To achieve a high dynamics performance vector control of PMSM drive is employed. In vector control stator current is decomposed into two parts- flux generating component and torque generating component. These two currents require separate control to control the flux and torque produced by motor separately like dc machine. The complete drive has two loops- inner current control loop, and outer speed control loop. In this paper fuzzy-logic is employed and investigated for all three controllers (one as speed controller and two as current controllers). Fuzzy logic controllers are used with input and output scaling factors. Each controller has their separate input and output range, so tuning (selection of scaling factors) of three controllers are different. Tuning is done observing the values at input and output of controller by using PI controller by keeping the interval of membership function [-2 2] in mind. Simulation is done in MATLAB for various operating conditions. Simulation results show the validity of proposed controllers.