Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

[SOLVED] Coupling Rectifier Output to an Isolated Forward Converter

Status
Not open for further replies.

darkseid

Member level 1
Joined
Nov 9, 2010
Messages
40
Helped
5
Reputation
10
Reaction score
4
Trophy points
1,288
Activity points
1,536
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

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,940
Helped
14,144
Reputation
28,547
Reaction score
12,829
Trophy points
1,393
Location
Bochum, Germany
Activity points
278,148
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

Member level 1
Joined
Nov 9, 2010
Messages
40
Helped
5
Reputation
10
Reaction score
4
Trophy points
1,288
Activity points
1,536
What kind of isolation (along with bypass resistor) should i use between the rectifier output and forward converter input. Really appreciate your help.
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,940
Helped
14,144
Reputation
28,547
Reaction score
12,829
Trophy points
1,393
Location
Bochum, Germany
Activity points
278,148
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

Member level 1
Joined
Nov 9, 2010
Messages
40
Helped
5
Reputation
10
Reaction score
4
Trophy points
1,288
Activity points
1,536
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

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,940
Helped
14,144
Reputation
28,547
Reaction score
12,829
Trophy points
1,393
Location
Bochum, Germany
Activity points
278,148
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.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top