Application Report
SPRA524
Digital Signal Processing Solutions March 1999
Space-Vector PWM With
TMS320C24x/F24x Using Hardware and
Software Determined Switching Patterns
Zhenyu Yu Digital Signal Processing Solutions
Abstract
Space-vector (SV) pulse width modulation (PWM) technique has become a popular PWM
technique for three-phase voltage-source inverters (VSI) in applications such as control of AC
induction and permanent-magnet synchronous motors. This document gives an in-depth
discussion of the theory and implementation of the SV PWM technique.
Two different SV PWM waveform patterns, one using the regular compare function on the Texas
Instruments (TI
ä
) TMS320C24x/F24x digital signal processors (DSPs) and another implemented
with the SV PWM hardware module on the TI TMS320C24x/F24x DSPs are presented, with
complete code examples for the TMS320F243/1. At the end, a complete AC induction motor
control application is discussed to show the effectiveness of both approaches.
PWM waveforms of the presented implementations and experimental data in the form of motor
currents are shown and discussed. A full TMS320F243/1 program example is attached. The
observation of dead band imbalance for the hardware-implemented SVPWM pattern in this report
has not been seen in other publications.
Contents
Introduction ......................................................................................................................................................2
Background......................................................................................................................................................3
Theory of SV PWM Technique..................................................................................................................3
SV PWM Waveform Patterns....................................................................................................................9
Application in Three-Phase AC Induction Motor Control................................................................................20
Experimental Results .....................................................................................................................................22
Conclusions ...................................................................................................................................................22
References.....................................................................................................................................................24
Appendix A. Program for Open-Loop Three-Phase AC Induction Motor Control With SV PWM Technique
and Constant V/Hz Principle ..........................................................................................................................25