A predictive control technique for PWM-rectifier in vector controlled induction motor drives

In the paper, an optimized control technique of an active front-end is described with reference to induction motor drives with a voltage source inverter combined with an active voltage source rectifier. Both the motor-side and line-side PWM power converters employ IGBTs as switching devices. Based on a simplified analytical solution of the system mathematical model in a discrete digital control, a coupled control plus modulation technique is pointed out. It is able to estimate the values of the interesting electrical quantities easily in some switching instants within the control sampling period. This allows one to evaluate the width of the different modulation intervals directly. A very simple method to recognize the modulation sector quickly in the complex plane is also proposed. A numerical analysis is performed in order to test the reaction capability of the active front-end to different heavy variations of the operating conditions of the drive.