T19.5 - An Enhanced Carrier-Based PWM with Reconstructed Modulation Waves for Three-Level T-Type NPC Inverters in Electric Aircraft Propulsion Applications

In this paper, a new carrier-based PWM (CBPWM) strategy is proposed for a three-level T-type neutral-point-clamped (3L-TNPC) inverter in electric propulsion applications. For a civil aircraft, the performance during the cruising stage, which is usually the longest in the typical mission profile with lower-rated output power, relies on high-efficiency electric propulsion. Meanwhile, its high reliability is realized on the premise of balanced neutral-point (NP) voltage. To leverage the above advantages at the same time, in this work, by adopting the reconstructed modulation signals, not only can the NP voltage ripple be mitigated, but also the switching losses are reduced effectively. Moreover, the active NP voltage balancing capability can be achieved by injecting adaptive zero-sequence voltage (ZSV) in specific intervals of pulse trains.