A Single-Phase Double T-Type Seven-Level Inverter

A single-phase double T-Type seven-level inverter is proposed in this paper. It consists of a single DC source, three series-connected capacitors, a double T-type network, and a half bridge circuit. The double T-type network helps synthesize three output voltage levels, and then with the half-bridge circuit seven output voltage levels including a zero voltage level are achieved. Compared with the existing single-phase seven-level inverters, both the number of power components and component stresses are reduced. A carrier-based modulation scheme is discussed and a voltage self-balancing circuit is presented to solve the de-link voltage imbalance issue. Both simulation and experimental results are presented to verify the proposed single-phase double T-type seven-level inverter.