Real-Time Implementation of Multi-Dimensional Five-Phase Space Vector PWM Using Look-Up Table Techniques

Space vector PWM (SVPWM) has been recently developed for multi-phase motor drives on the basis of the multidimensional space approach. Although showing excellent characteristics with regard to performance, the multi-dimensional based SVPWM is very difficult for real-time implementation due to the excessive computational demands of the algorithm. A further difficulty stems from the dependence of the computation time on the operating conditions. This paper attempts to alleviate these problems encountered in the real-time implementation of multi-dimensional SVPWM algorithms, by using look-up tables that include off-line information. The performance of the approximate algorithm based on the off-line calculations is evaluated by simulation for different requirements regarding the output voltage synthesis. The algorithm is finally implemented in a TMS320C6711 Texas Instruments DSP, thus proving the feasibility of real time implementation with fixed computational time, at the expense of the additional memory for the look-up table storage.