Research on improvement of FOC system for induction motor using fuzzy logic

The effects of mismatch between the induction motor and vector controller (field-oriented control) can be minimised by adapting the parameters in the vector control to the actual motor parameters, at all times. This requires monitoring of the motor parameters, but direct monitoring is difficult while the drive is in operation. Several methods have come to the forefront to minimise the consequences of parameter sensitivity in indirect vector-control schemes. In this paper two methods to compute stator frequency are presented. A fuzzy logic approach is used to combine both methods in order to reduce flux orientation sensitivity to parameter uncertainties. Taking into account the saturation effect and using fuzzy logic technique, the combined control scheme has been analysed under steady state and transient conditions. The simulation results confirm that the FOC control is robust under the variation parameters and load torque.