Soft-switching three-level inverter
A soft-switching three-level inverter (S3L inverter) is a high-efficiency power electronic inverter intended, in particular, for use with three-phase drives, as a grid-tie inverter for photovoltaic installations or wind turbines and in power supplies. The topology was developed in 2009 at HTWG Konstanz (Constance University of Applied Sciences).
Source: Wikipedia — Soft-switching three-level inverter (CC BY-SA 4.0)