Time-Optimal Voltage Vector Transition Scheme for Six-Step Operation of PMSM

This article analyzes the instantaneous flux trajectory of a permanent-magnet synchronous machine (PMSM) in the six-step operation. Not only the flux dynamics but also the instantaneous voltage vector are included in the analysis. Based on the analysis, a time-optimal voltage vector transition scheme is proposed for the six-step operation of a PMSM. In the proposed scheme, a few steps are added in the transition of the voltage vectors to bring additional degrees of freedom, and they can enhance the dynamic performance conspicuously under the given current constraint. Simulation and experimental results are provided to verify the proposed scheme. For the stepwise torque command, the proposed scheme saves the settling time more than 50% with 60% reduction of the peak current compared to the conventional transition method.

Automated summary

This article analyzes the instantaneous flux trajectory and voltage vector of a permanent-magnet synchronous machine in the six-step operation, proposing a time-optimal voltage vector transition scheme to enhance dynamic performance significantly. Simulation and experimental results validate the effectiveness of the proposed scheme, showing over 50% reduction in settling time and 60% reduction in peak current compared to conventional methods.