Maximizing power: Serialization of medium voltage IGBTs for a 3-Level NPC 6.6kV/10MW converter

The serialization of semiconductors arises as an attractive solution at the time of engineering high voltage and high power Variable Speed Drive equipments. The voltage balancing is the main concern, as the maximum blocking voltage of the components can be exceeded during the turn off process. In this paper auxiliary low-loss circuitry for Medium Voltage modules series-connection is presented for a 3-Level NPC topology 6.6kV output voltage inverter. They are considered both the gate control for possible asymmetries during turn-off and a passive clamp circuit to match the stationary unbalances generated by the Ices (Leakage Current) and Qrr (Recovered Charge) differences between the serialized modules. The analysis criteria is justified, and experimental results in a real high-power medium-voltage (6.6kV and 10MW) converter are served.