[chbot] Scrounging for big switch mode PSUs

Wes Edwards edwardsw at steadfast.co.nz
Thu Mar 7 22:45:40 GMT 2019


Hi Peter

 

Wouldn’t 3 x 1000W @48V units produce either 1kW @ 144V (series) or 3kW @48V (parallel)?  I don’t think you could get 3kW at 114V unless you had 9 units (3 banks in series, with each bank paralleled)?

 

In any case, I have serious doubts that you can combine PSUs like that either in series or in parallel –you can’t guarantee that the load would distribute evenly – it is more likely that one unit with very slightly different specs would end up taking more load and fail (possibly spectacularly).  I think PSUs are very unlike batteries in this regard.

 

There may be some exceptions with PSUs that are specifically designed to do this, or specialised control electronics to manage the load sharing, but I don’t know of any.

 

Wes

 

From: Chchrobotics <chchrobotics-bounces at lists.ourshack.com> On Behalf Of Peter Harris
Sent: Friday, 8 March 2019 10:22 a.m.
To: chchrobotics at lists.ourshack.com
Subject: [chbot] Scrounging for big switch mode PSUs

 

Hi All

As part of my domestic grid tied battery system I need an isolated DC power supply capable of producing 2.5kW at between 120V & 300V  The voltage does not need to be adjustable.

 

My plan is to purchase 3 x 1000W 48V caged units and series them to yield 3kW @ 144V however I thought I'd see what folks have gathering dust before I place the order. There a many configurations that would do the trick 2 or 3 x 76V or 96V or even a stack of meaty 24V units.

 

If you have a suitable combination you would like to dump, sell or swap for beer please let me know.

 

  Peter

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