A New Three-Level Active Neutral-Point-Clamped (A-NPC) Multilevel Converter Topology

This paper proposes a new three-level active neutral-point-clamped (A-NPC) converter topology. The classic three-level A-NPC converter's phase-leg (per-phase) comprises the four line-frequency (LF) and two full-cycle-switched high-frequency (HF) pulse-width-modulation (PWM) power switches such as the insulated-gate bipolar transistors (IGBTs). The phase-leg of the proposed A-NPC topology is realized utilizing four half-cycle-switched HF-PWM and two LF IGBTs. The LF-IGBTs within the proposed three-level A-NPC configuration are gated ON excluding the application of any dead-time, and maintained turned-on concurrently during the commutation of the LF switches for generating the intermediate voltage-level of zero. This overlap of the gating pulses throughout the voltage-level transition provides the soft-commutation and shoot-through condition for LF IGBTs, and makes these power switch devices to be turned-on simultaneously that increases the efficiency. The experimental results are provided to compare the switching characteristics of both classic and the proposed A-NPC converter topologies.