Implementation of discrete-time field-oriented current control

This paper studies performance sensitive issues encountered in the implementation of all-digital discrete-time field oriented current control of an AC motor. In particular, the focus here is on the interface between the vector current control algorithm itself, and the motor/inverter system. The effects of interface components such as antialiasing filters, rotational transformations, and phase-to-line-voltage transformations are analyzed. In addition, 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