I am studying the function principle of a dual active bridge (DAB) dc-dc converter. What I don't understand is why the dc component of the inductor current is always zero in steady state (or at least, this is what all the papers I read up to now are showing). In my simulation the dc component of the inductor current is not zero although the steady state is reached.
It's described pretty well in here: **broken link removed**
There should be zero inductor current at steady state due to the fact that the volt-time product applied to both the primary and secondary should always average to zero. This condition will prevent DC current from appearing. However it will not always cause existing DC current to converge back to zero. That would have to be enforced by the control circuit, or by adding some DC resistance to the primary/secondary paths.
Are you doing transient simulations? If so it may be just an initial condition thing.