Newbie question, would really appreciate some help.
I am modelling a simple full-bridge inverter in Matlab. I've used the supplied example file of a full-bridge inverter that was developed by the Matlab engineers.
The DC current appears to be wildly fluctuating / inverting. (see image below)
I have always thought that DC-AC inverters had (by definition) a DC and an AC side and that thus naturally the current on the DC side could only flow in one direction. Also, when I look at the DC input voltage, it is constant and positive.
1. How does a DC-AC inverter's input current change with time? (ie. Is this actually how DC-AC inverters behave?)
2. Is it at all possible to have a positive voltage and a negative current, as we see in the model? (or does that break physics....)
3. If this model is insufficient, any suggestions on how I can model a DC-AC inverter?
The matlab model, straight from the built in examples but with a couple of extra scopes for monitoring:
The strange-looking DC input current and voltage:
The inverter AC output current and voltage: