PROJECT TITLE :

A Generalized Algorithm to Eliminate Spikes of Common-Mode Voltages for CMVRPWM

ABSTRACT:

This paper presents a generalized algorithm to eliminate spikes of common-mode voltages (CMV) caused by dead-time result for common-mode voltage reduction pulse width modulation (CMVRPWM). The characteristics of the CMV spikes for the popular CMVRPWM methods (AZSPWM1, NSPWM, CRLO-CMVRPWM, and SLO-CMVRPWM) are studied and compared by analyzing the intense switch pulse patterns. The proposed CMV spikes elimination methodology directly adjusts the injected zero-sequence voltages instead of the durations of the adopted voltage space vectors to avoid the overlaps of the adjacent dead time periods. The CMV spikes can be eliminated regardless of the output voltages within the dead time periods; therefore, the signs of part currents are not required to detect and overcome the matter caused by the resolution of this sensors when the part currents approach to zero. In addition, a good method by online choosing low or high active pulses for the three legs is proposed to ensure that at most one leg switches between adjacent carrier periods. The proposed methodology is generalized and effective for all the CMVRPWM with symmetrical switch pulse patterns and no simultaneous switching drawback. The simulation and experimental results validate the effectiveness.