Experimental verification of direct dead-time Control and DC-link neutral-point balancing of a three level neutral-point-clamped (3L-NPC) VSC

The neutral-point balancing of 3L-NPC converter has been studied in many works in the past. However, all state-of-the-art methods have in common that the information of the energy-flow direction is needed. Recently, Direct Dead-time Control (DDTC) has been presented which controls the converter dead-times to balance the dc-link independent from the energy-flow direction. This paper presents an experimental investigation of DDTC for different load conditions and control schemes.