Electronically controlled changeover switch with mains isolation?

Hello,
We need to do a (small as possible) 2kW SMPS car battery charger which is bi-directional so that it can also put the battery energy back into the mains.
Do you think the attached is a way to do it?
If so, can you state if the needed “changeover switch" exists anywhere?
Preferably the changeover switch could be electronically controlled, and could switch between circuits whilst preserving their mains isolation from each other.
Please find schematic attached.

A grid-tied inverter, which is half of what you are trying to do, needs:

• To be a sine wave output synchronized to the existing line waveform.
• To have a protection circuit so that it never puts power onto the line unless there is already a voltage there. And to stop delivering power if the upstream mains power is lost.

The reason for the protection is to protect utility workers. If they need to turn off power to a section of the network to work on it, either due to an emergency or just maintenance, they presume that the lines are dead. If a house in the neighborhood is pushing power onto what should be de-energized wires, someone is probably going to get hurt.

Check whether you need authorisation/approval from the utility to pump power back into the mains. I'd expect there to be Regulations concerning this.

Forgive me, but to me it's not entirely clear where the "contacts" of the changeover switch need to go. Am I right in saying that it switches:
PFC output TO switching bridge (position 1) OR rectifier bridge (position 2)
and
Battery TO rectifier bridge (position 1) OR switching bridge (position 2)

And am I also right in saying that what you've drawn here is just for the DC-DC conversion - that is to say, the PFC circuit will supply DC to the switch, and the Grid-Tied-Inverter will take a DC input (and we're assuming that the GTI is an external block that we're not concerned with here?).

I would have thought that mechanical contactors would be fine for the job - perhaps you could even get mechanically interlocked ones that could prevent anything catastrophic happening if the controller screwed up? Or, do your size constrains mean that you're after a solid-state solution?

Thanks for clarifying
Tom

the contacts make the full bridge converter bi-directional.
GTI is part of it, but not related directly to the changeover switch.
We would prefer electronic actualted contactors to make it small.

Any info you may have on a single circuit which is an active PFC one way, and a GTI the other way, would be greatly appreciated.

It all seems feasable enough, although surely it only works with an on-average 1:1 voltage transfer ratio accross the converter. Is it the intention for the 1:1.4 ratio of the transformer to provide a bit of "headroom", so the PWM controller can regulate back a bit and compensate for changes in the charge state of the batteries?

I'm no power electronics engineer, by the way. I'm sure others will have something more in-depth to offer...

Oh, and it may be useful to know whether this will be for 110v or 240v mains, or universal?

yes the transformer ratio is not optimised for both ways, the controller has to make up for it by suitably varying the duty cycle depending on the way.