Implementation of discrete-time field-oriented current control

Performance sensitive issues encountered in the implementation of all-digital discrete-time field oriented current control of an AC motor are studied. The focus is on the interface between the vector current controller algorithm itself, and the motor system. The effects of interface components such as antialiasing filters, rotational transformations, and phase-to-line-voltage transformations are analyzed. A straightforward all-digital pulse width modulator is presented along with a new algorithm to naturally inject triplen harmonics into the motor line voltages, and thereby increase power supply utilization by 15%. Real-time operation of a discrete-time vector current controller verifies the analysis.<
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