Reduction of dead-time effect on the common mode voltage of an open-end winding machine

Open-end winding (OEW) three-phase drives with dual inverter configuration present high voltage gain, which is very valuable for electric vehicle (EV) applications. However, they can lead to zero-sequence currents and common mode voltages (CMV). A solution for the aforementioned problems is to control the inverters with only odd or even space vectors (SVs). Nonetheless, during dead-times the actual SVs of the inverters vary with the polarity of the load currents which can lead to short pulses in the CMV. First, this paper discusses an approach for determining the actual SVs of the inverters during the dead-times. Based on this, a strategy for selecting the sequence of SVs as a function of the load current polarities for eliminating the spikes in the CMV is proposed. The impact of the proposed strategy on the load voltage and current harmonics as well as on the switch power losses is investigated. The findings of this work are supported by simulation results.