Forward Converter ground question

[yokahu]

Hi guys,

I want to design a 24Vdc-240Vrms system that will use a Forward Converter (dc-dc) and an H-Bridge Inverter (dc-ac), but I’m confused with the grounds.

The Forward Converter has a transformer in the middle that technically divides the circuit in two, providing different grounds.
So my question is: can I connect the two grounds without affecting the proper function of the Forward Converter?

The reason is that on my design, the ground of the inverter (DC section) has the same ground as the inverter’s control-circuit. But the input voltage of the inverter’s control-circuit will come from the input voltage of my Forward Converter. If that is done, it would be the same as connecting the two ground of the Forward Converter, before and after the transformer.

Thanks for the replies.

 

[mtwieg]

Hi guys,

I want to design a 24Vdc-240Vrms system that will use a Forward Converter (dc-dc) and an H-Bridge Inverter (dc-ac), but I’m confused with the grounds.

The Forward Converter has a transformer in the middle that technically divides the circuit in two, providing different grounds.
So my question is: can I connect the two grounds without affecting the proper function of the Forward Converter?

It shouldn't affect the forward converter itself, but isolation is usually necessary for the inverter to work safely with many loads.

The reason is that on my design, the ground of the inverter (DC section) has the same ground as the inverter’s control-circuit. But the input voltage of the inverter’s control-circuit will come from the input voltage of my Forward Converter. If that is done, it would be the same as connecting the two ground of the Forward Converter, before and after the transformer.

Not sure what you mean here. Why would an "input voltage" (is it a voltage reference, or enable signal or something) for the inverter control circuit need to be referenced to the primary side of the forward converter?