Vector based dead-time compensation for a three-level T-type converter

This paper proposes a new vector based dead time compensation method for a three-level T-type converter. The origin of the dead time voltage error is analyzed in detail under different switch commutation processes and load conditions. Based on the dead time voltage error for each phase, an error voltage vector is defined to indicate the effect of the dead time on the reference voltage vector from vector synthesis point of view. To cancel the dead time error voltage vector, the reference voltage vector is adjusted accordingly based on load current directions. Different from the studies presented in literature, the operation of the proposed dead time compensation method can be extended to over modulation region. The effectiveness and the advantages of the proposed vector based dead time compensation method are verified by both simulation and experimental results.