Experimental 500kW Hybrid Si/SiC ANPC Inverter

Abstract:
The paper presents an experimental 500kW hybrid Si/SiC active neutral point clamp (ANPC) inverter made of 62mm modules. The inverter uses only two SiC MOSFETs and one decoupling capacitor (Fig 1.b) instead of four SiC MOSFETs (Fig 1.c).The main challenge of this topology is damping thedecoupling oscillation caused by the decoupling capacitor and the native MOSFET switching ringing.The special oscillation damping strategies are demonstrated that the clean and high speed switching ofSiC MOSFET is archivable. The turn-on losses of the SiC MOSFET are optimized with the parasitic turn-on effect and it shows that the method works reliably when the sensitivity factors are considered duringthe selection of the control parameters. With 10kHz switching frequency and 3-level output, the invertercan produce low current ripple and hence reduce the filter inductor volume. The testbench was run for 2 hours continuously and the temperature of all critical components were in the safe operation area.