Power Supply Converter

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Chris1978

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Cyprus
Dear All,

Hello!!

I am looking for a power supply that converts a single phase 220V to a 3 phase frequency regulated 0-380V, regulated by frequency and voltage less than 3KVA.

The system will be used on a measurement unit to perform measurements of power transformers.

Ty
 
Jraef

Jraef

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San Francisco Bay Area, CA, USA
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Electrical Engineer
At 3kVA I've seen it done, but it's going to be a VFD for motors. It will use a voltage booster front-end rectifier. There is a company out there who does this using Hitachi drives and building their own front-end rectifier for it with a booster. I can't remember the name right now but I'll think of it, probably tomorrow when I'm not trying to think of it.

The output is going to be PWM, so I'm not sure what effect that will have on your transformer testing. If you find it, you may want to add an output sine wave filter.

Eh, remembered it sooner than I thought. Looks as though they switched to using TECO instead of Hitachi drives now however.
http://www.invertersdirect.co.uk/Ca...5f4-142bc432f4e9/DIGITAL-240-TO-415-INVERTERS
 
Last edited:
Besoeker

Besoeker

Senior Member
Location
UK
Jraef said:
At 3kVA I've seen it done, but it's going to be a VFD for motors. It will use a voltage booster front-end rectifier. There is a company out there who does this using Hitachi drives and building their own front-end rectifier for it with a booster. I can't remember the name right now but I'll think of it, probably tomorrow when I'm not trying to think of it.

The output is going to be PWM, so I'm not sure what effect that will have on your transformer testing. If you find it, you may want to add an output sine wave filter.
Click to expand...
A long time ago, we did something like this. The motors were 690V and the inverters were 400V output. You couldn't get 690V VFDs at that time time so we had a step up autotransformer on the output. It had to have a gapped core to prevent saturation if there was any asymmetry in the inverter PWM output.

I don't know if this something the OP may to have to consider in his case.
 
M

mike_kilroy

Senior Member
Location
United States
YEP, Perfectly ldoable - if you work with the right folks

YEP, Perfectly ldoable - if you work with the right folks

Chris1978 said:
Dear All,

Hello!!

I am looking for a power supply that converts a single phase 220V to a 3 phase frequency regulated 0-380V, regulated by frequency and voltage less than 3KVA.

The system will be used on a measurement unit to perform measurements of power transformers.

Ty
Click to expand...

Sure. Some of us take 220v 3ph in and output variable freq 0-380vac 3ph all the time - into induction motors via auto-transformers on the output. Yep. Doable. Did you give 1/10th enough info to quote something yet? Nope. To do this you just need to find those companies who do this kind of stuff regularly. Missing info of course is the amperage range, the frequency range, the dynamics of the load changes, if PWM noise is acceptable, etc., etc., etc. Many VFDs will not work flawlessly with a non motor load on their output. Most will not accept a step change in load on the output. all this needs definition.

So easy answer is yep, can do. Now find those who do this kind of thing.
 
GeorgeB

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
My Rube Goldberg approach would be a 1:2 step-up transformer (oversizing not required) and a 7.5HP or 10HP VFD. Since your inrush could be minimal starting at low volts and frequency, the 7.5 would probably do ... only need 380 with 440 (460?) capability. jraef's experience and suggestion of a sine filter would be smart. If you can better define your needs, perhaps you'll get better help.

The VFD manufacturer should be consulted on suitability for driving your transformer load and with single phase in.
 
M

mike_kilroy

Senior Member
Location
United States
mike_kilroy said:
Sure. Some of us take 220v 3ph in and output variable freq 0-380vac 3ph all the time - into induction motors via auto-transformers on the output. Yep. Doable. Did you give 1/10th enough info to quote something yet? Nope. To do this you just need to find those companies who do this kind of stuff regularly. Missing info of course is the amperage range, the frequency range, the dynamics of the load changes, if PWM noise is acceptable, etc., etc., etc. Many VFDs will not work flawlessly with a non motor load on their output. Most will not accept a step change in load on the output. all this needs definition.

So easy answer is yep, can do. Now find those who do this kind of thing.
Click to expand...

I meant to say 1 phase input
 
Jraef

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
mike_kilroy said:
Sure. Some of us take 220v 3ph in and output variable freq 0-380vac 3ph all the time - into induction motors via auto-transformers on the output. Yep. Doable. Did you give 1/10th enough info to quote something yet? Nope. To do this you just need to find those companies who do this kind of stuff regularly. Missing info of course is the amperage range, the frequency range, the dynamics of the load changes, if PWM noise is acceptable, etc., etc., etc. Many VFDs will not work flawlessly with a non motor load on their output. Most will not accept a step change in load on the output. all this needs definition.

So easy answer is yep, can do. Now find those who do this kind of thing.
Click to expand...
Hey Mike,
What's the input current base on the output current of one of those?
.
.
.

NO WAIT!!! STOP!!! IT'S A JOKE!!!
:jawdrop:
 
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