Towards a 99.5% Efficient All-Silicon Three-Phase Seven-Level Hybrid Active Neutral Point Clamped Inverter

With the deployment of PV energy generation increasing, the need to optimize efficiency of the power conversion from the PV panel to the AC grid while minimizing the material effort and the realization cost has gained significant importance. Accordingly, this paper presents a 12.5kW 99.35% efficient three-phase inverter using commercially available low-voltage silicon power semiconductors. A hybrid sevenlevel topology is employed, with each phase comprising an Active Neutral Point Clamped (ANPC) front-end connected to a Flying Capacitor Converter (FCC) stage, which leads to a low overall volume and weight, i.e. a volumetric power density of 3.4kW/dm
³
(55.9W/in
³
) and a gravimetric power density of 3.2kW/kg. Additionally, this topology shows a smaller capacitance requirement and consists of less switches than the conventional FCC topology. Finally, a comprehensive optimization shows that with the next generation of 200V silicon devices it is feasible to achieve a peak efficiency of 99.5%.