Current-Feedback Control at Constant Sampling Frequency Applied in Rotor -Field-Oriented Induction Machine Drives

Current-feedback modulation based procedures offer the fastest response and provide accurate current control, without tracking errors. The two modulation procedures presented in this paper are working with constant sampling frequency given by a fixed frequency clock signal. Sequential motion of the voltage space phasor can be achieved if the sampling signal is shifted with 1/3 of the sampling period for each phase, that will guarantee only adjacent and zero voltage vector selection. The proposed techniques were tested by simulation as part of a rotor-field oriented vector control structure for a cage induction motor drive.