Current Routing in Neutral Voltage Level of Hysteresis Current Controlled Three-Level Active Neutral Point Clamped Inverter for Low Fundamental Frequencies

Inhalt:
Three level converters, especially Neutral Point Clamped (NPC) converters, are gaining popularity in industrial applications. Active Neutral Point Clamped (ANPC) [1] instead are rarely used by now. The ANPC has some significant advantages compared to NPC, like loss balancing feasibility or the ability to control the current path in neutral voltage level. It is also possible to use two current paths at the same time to reduce the losses of the inner semiconductors. For currents with a low fundamental frequency, this is very important because the inner semiconductor usually is in on-state for a whole half sine wave. In this case, the stress of the inner semiconductors can be significantly reduced by using both current paths.