Hello. I have problem in simulating my circuit using Multisim. The schematic of my circuit is attached.
The TL494CN and HCPL3120 circuit simulation work fine. But, when full bridge IRFPC40 is connected to them, there is error in simulation. there is no voltage at the output side of the full bridge. If I delete the IGND of U3 and U4, the simulation is error.

My question is:
1. How I must connect the HCPL3120 to the IRFPC40 gate?

2. What happen when we used toroidal transformer to transfer the signal, because I used it before, and no problem in gate signal loop. I replaced isolation function of transformer by using the HCPL3120 optocoupler gate driver.

Thanks guys.

 

Oh, guys, I'm really sorry, I upload a wrong schematic.

Here, I upload the schematic I talking about.