On the diagram above there are 2 connections labeled +HVDC and -HVDC, please can anyone explain this cos it gets me very confused. Is this the amplified voltage from the IGBT?, Ive seen IGBT's in inverters but I noticed that there is always a step up transformer somewhere. I thought IGBT's are just fast switches. If I am supposed to connect power to this part of the circuit, how much should that be because from the look of the diagram, whatever is connected to these points will find its way to the low DC section via Q1. Thanks for reading.