Nine-level inverter based on NPC topology for high frequency operation

This paper presents the novel concept of an inverter with nine-level phase-to-phase voltage. A branch of the converter contains only one bi-directional switch more than the classic 3-level diode-clamped topology. However, such a modification allows to increase the levels of phase-to-phase voltage from five to nine. Furthermore, the proposed topology significantly reduces the value of the current passing through diodes of the NPC inverter and number of switching operations of diodes. The proposed topology allows to design high frequency, low voltage, low power NPC-based inverter with the use of MOSFET or GaN transistors. The distribution of losses in the components is much more uniform in the proposed converter than in the equivalent nine-level inverter diode-clamped. The topology of the proposed inverter is suitable for the use of GaN transistors with bi-directional blocking.