Fuzzy control of AC-drives fed by PWM-inverters

A novel control method based on the principle of direct self control in connection with a fuzzy controller is presented. The two inputs of the fuzzy controller are the errors of the flux and torque transformed by fuzzy sets in various categories valued by membership functions. Fuzzy-logic-based production rules combine the inputs and determine the output variables in the form of inverter voltage phasors and its pulse times. The special controller contains a nonlinear regulator and a pulse-width modulator to keep constant the phase frequency of the control system