PI Design software for 3 phase design

Posted by: ljarillas on 05/14/2009

I need to design a three phase power supply for a metering application. Can the PI Expert Design software do 3-phase SMPS design?

I was looking at the DER-58 but I need more that 3W and more output voltages. I was also looking at DER-105 but input is only from 207VAC - 400VAC.

Any help is much appreciated. Thank you.

Comments

What are your input and output requirements?

PI Expert does not have capability to design with "StackFET".

Hi Tucker,

Thanks for the reply. Initial requirements are as follows:

Input: 85VAC - 580VAC
Output: 15V @ 1.2A, 3.3V @ 500mA, 4V @ 500mA (peaking to 2A)

Note that the 4V will be averaging 500mA but it will peak at 2A when GSM modem is transmitting.

Thanks.

-Leonard

I've been reading a few posts in the forum regarding the StackFET design. So can you use this procedure?

1. Use the PI Expert software to generate your preliminary design (85VAC - 300VAC as input).
2. Put another high-voltage MOSFET in series with the PI chip
3. Change other components to higher voltage rating (700V-800V if input is three phase)
4. Use the input stage (left of C9) on the DI124?

I'm sure it's more complicated than this. But for someone who is not a power electronics expert, where do we start?

Thanks.

I am in a similar situation and was also considering the process suggested by Ijarillas. In addition however, I noticed that PIXIs Designer doesn't limit the input voltages, so that could be used for the transformer design.
Any further suggestions?

I am also designing a 3-phase power supply and am facing the same issues that you are. I am using LNK304P as a Buck Converter. I am stacking up the capacitors for a higher voltage rating and also am going to try putting in the extra FET with the same biasing that they show in DI-124. The only difference is I will tie the FET drain to the positive rail because there is no transformer. I don't see any reason why it wouldn't work.

The best approach is to design the transformer using a PIXLS spreadsheet, and ignore the VDRAIN warnings.

Then add the required series MOSFET based on the PIXLS RMS Drain curent calculations.

Pls see my reply about 4 posts up.