RogerRoger25
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- Exeter
Does anyone have information on how to calculate the secondary line voltages for this type of transformer? Information generally would be gratefully received!!!
6 phase forked star secondary wound transformer
- Thread starter RogerRoger25
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- San Francisco Bay Area, CA, USA
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- Electrical Engineer
How about an explanation of how you are using this and why you need to know? Because if it's just the 6 phases you want to know about, that's easier to describe than the 9 possible connections available.
Got a diagram?
Do you think he means hexaphase?
Got a diagram of a forked star?
Diagram
Diagram
LMGTFY
Diagram - http://www.vias.org/matsch_capmag/matsch_caps_magnetics_chap6_12_07.html
Diagram
LMGTFY
Diagram - http://www.vias.org/matsch_capmag/matsch_caps_magnetics_chap6_12_07.html
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
That lower diagram is something I was aware existed in theory, but have never needed to implement. 6 phase (hexaphase) as shown in the upper diagram on that page, used as an input to a 12 pulse rectifier, yes. But the "forked wye" thing is not necessary for that. Still, there are people who sit around thinking about this sort of stuff for all kinds of off beat uses.
Is this xfmr used to do something similar?
D - DDD
4160-1400/1400/1400 0 deg/+20 deg/-20 deg
3500 kva labeled scr application
ties a 4160 bus to a large vfd that powers a 4160 3500 hp motor
only used for starting then a contactor transfers in
http://forums.mikeholt.com/showthread.php?t=182722
D - DDD
4160-1400/1400/1400 0 deg/+20 deg/-20 deg
3500 kva labeled scr application
ties a 4160 bus to a large vfd that powers a 4160 3500 hp motor
only used for starting then a contactor transfers in
http://forums.mikeholt.com/showthread.php?t=182722
Hexaphase is commonly used for six-pulse rectifiers for high current low voltage rectifiers. There is one device (SCR typically) in each leg. The merit is that you have just one semiconductor voltage drop as opposed to two with a full wave rectifier. The devices are subjected to a higher PIV but if the system is just a few tens of volts that is not usually a critical factor.
Tony S
Senior Member
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- Resting under the Major Oak UK
The only dealings I’ve had with hexaphase is with MAR’s and that’s going back to when Noah built the ark.
The calculations for voltage are pretty basic, phase to phase voltage equals phase to neutral voltage, an equilateral triangle.
The calculations for voltage are pretty basic, phase to phase voltage equals phase to neutral voltage, an equilateral triangle.
You mean mercury archaic rectifiers?
Tony S
Senior Member
- Location
- Resting under the Major Oak UK
Yes, but the transformer has a few extra windings for ignition and excitation.
We did a bunch of them, 70kA total, for an anodising line. the supply was from a couple of local ONAN focal transformers supplying 660V and our hexaphase units had auxiliary 400V tap to feed the phase control firing circuits.
Not the kind of thing where you can afford to get your sums wrong.
RogerRoger25
Member
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- Exeter
Hi Guys,
Apologies for the delayed response, this is a question presented to me in an exam and I had no idea about it. Reference material is very hard to come by, hence my question on here.
The primary can be either delta or star three phase as far as I am aware and the secondary has a total of 9 windings.
Vague I know.......
Apologies for the delayed response, this is a question presented to me in an exam and I had no idea about it. Reference material is very hard to come by, hence my question on here.
The primary can be either delta or star three phase as far as I am aware and the secondary has a total of 9 windings.
Vague I know.......
RogerRoger25
Member
- Location
- Exeter
Reply
Reply
Do You have the calculation method?
Reply
We did a bunch of them, 70kA total, for an anodising line. the supply was from a couple of local ONAN focal transformers supplying 660V and our hexaphase units had auxiliary 400V tap to feed the phase control firing circuits.
Not the kind of thing where you can afford to get your sums wrong.
Do You have the calculation method?
Does the second diagram in post #7 pertain?
I've never seen such a beast in real life and I can't imagine what it could be used for.
A nine phase rectifier.............?
Well, I desinged it so I suppose the answer is yes.
But what do you want to calculate?
RogerRoger25
Member
- Location
- Exeter
The secondary line voltages but I would like to see the full method if possible?
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