[SOLVED] Coupling Rectifier Output to an Isolated Forward Converter

[darkseid]

Hi

I am developing a system comprising of a three phase rectifier connected to an isolated forward converter. Both the systems are working individually when I simulated them on PSPICE, but when I am connecting the output of the rectifier as the input DC to the forward converter, PSPICE fails to converge. The following are the specs:

Rectifier Output: 40V DC (using an LC filter)
Forward converter output: 30V DC @ 1.5A

What all factors do we need to consider while coupling two or more systems.

regards
Darkseid

 

[FvM]

Sounds like an every days simulation problem. Possibly the converter simulation don't like zero input voltage. Try with suitable .IC settings. Also the isolation should be bypassed by a mnimal conductance (Mohm resistor).

 

[darkseid]

What kind of isolation (along with bypass resistor) should i use between the rectifier output and forward converter input. Really appreciate your help.

 

[FvM]

You don't need any isolation. But if the simulation circuit contains floating parts, it may cause problems and should be bypassed with a highohmic resistor.

 

[darkseid]

Hi

I tried giving initial voltage to the filter capacitor at the rectifier output. Also connected a 1 meg resistor to the ground for the forward converter. Still not converging.

 

[FvM]

In this case, you should analyze which circuit nodes fail to converge and try to understand the reason. In some cases, adjustment of transient analysis parameters can help.