A study of conventional and fuzzy PI controller CSI fed induction motor

A comparative study has been made for closed loop performance of CSI fed induction motor using fuzzy logic PI controller with conventional PI controller. A slip control scheme has been used for the induction motor. The evaluation of the controller´s behavior is made through computer simulation with MATLAB coding. The starting transients of the motor are investigated for different operating speeds. It has been shown that for fuzzy controller, once the parameters are selected for a specified load and speed, it works for all other speed whereas for conventional PI controller, the parameters have to change for each load and speed setting. The fuzzy controller reduces the over shoot value of speed approximately 2 to 5 % for the selected load. The peak value of input DC link current of the CSI is also less in fuzzy PI controller as compared to conventional PI controller. This reduces the rating of the semiconductor switches used in inverter and thus overall cost of the system.