A Comparative Study of Current Harmonics and Switching Frequency With Different Pulse Patterns in Duty-Cycle-Based Model Predictive Current Control

Abstract

Model predictive current control with duty cycle optimization has been widely studied and applied in permanent magnet synchronous motor drives. However, the commonly adopted pulse arrangement of virtual voltage vectors may not be optimal, since no rigorous mathematical proof is given and too many other types of pulse arrangements exist. Firstly, six pulse arrangement combinations of virtual vectors are defined as six patterns in this paper. Then, the effects of six patterns on current distortion and switching frequency are investigated. Based on the analysis, the existing commonly adopted pattern is proved not to be the best. Instead, another optimal pattern with minimal current harmonics and the lowest switching frequency is selected to achieve better performance and lower heat loss. Finally, an experimental comparative study is implemented in this paper. The results have verified that the pulse pattern selected by the proposed analytical approach can effectively reduce the current harmonics and switching frequency, compared with the commonly adopted one.