1000va ups transformer

[nazeerhussain]

Respected sir,
I am new commer in this forum and hope that your kind cooperation and assistance is always with me.I am designing a Line interactive 1000VA UPS. I am facing some problem w.r.t. transformer of ups i.e. detail of windings,transformer checking procedure, voltage references and connection of transformer with inverter board.

Thanking you in advance for cooperation!

Regards

 

[tpetar]

You can look other threads about ups/inverters in this forum just in search field type inverter or ups.
There is lots of circuits and theory.

 

[nazeerhussain]

Thank you very much for quick reply.By searching inverter/ups in this forum really i improved my bank of knowledge.
Thank you again for quick response.
Regards,

 

[ch wazir]

You should mention the required dc voltage to feed the ups whether that is 12,24,36 or 48 volts,you plz send the information and the formula regarding winding details will be sent.

 

[nazeerhussain]

Thank you very much for kind reply.The required dc voltage to feed the ups is 12 volts,plz send the information and the formula regarding winding details as early as possible.
Thanks a lot.
regards,

 

[BradtheRad]

This isn't meant to discourage you but such a project is very ambitious.

To produce 1000 VA, the transformer will require 95 amps at 12 V. (Add several percent to make up losses).

The primary windings of your transformer must handle that much current. DId you intend to wind the transformer yourself?

This also means hefty power cables to the battery. Something like 2 gauge. Shiny clean connections.

The circuitry must be substantial. Switching devices must carry upwards of 140 amps.

Using a 12 volt supply creates a challenge for a homemade inverter. Using a supply of 24V or higher would make such a project easier to construct/ adjust/ maintain.

 

[milind.a.kulkarni]

Yaa I do agree with BradtheRad....As per my knowledge 1000 va inverters generally works on 24 V ....so that max current rating of the transformer become 60 A design

 

[ch wazir]

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Thank you very much for kind reply.The required dc voltage to feed the ups is 12 volts,plz send the information and the formula regarding winding details as early as possible.
Thanks a lot.
regards,[/QUOTE
Hello Nazeerhussain,
plz note the required information:-
Core size:-2*3 inch if you want to convert it into cm then 1 inch=2.5 cm.The core is EI type Silicon.
Number of turns primary=290 turns,18 swg for 220v,340 turns for 240v.
Number of turns secondary=15-0-15 turns,11 swg (secondary centre tapped).
The secondary winding will be connected to switching side while the primary to the output side.Regards

 

[nazeerhussain]

Thank you BradtheRad for your kind technical opinion.I also do agree with you that winding of 1000va ups transformer specially primary side with 2 gauge wire is a laborous job.Working on heavy current circuit with power cables is also a time consuming job.your opinion is absolutly right that using a supply of 24V or higher would make such a project easier to construct/ adjust/ maintain.Thank you very much for reply.
regard,

 

[BradtheRad]

The table I looked at uses a conservative rating of 750 circular mils per amp. (The table was compiled by Fr. Thomas McGahee for Tesla coil builders.)

It states 2 gauge (American system) as the smallest wire which is suitable to carry 90 amps average continuous duty in open air.

However if we base it on 50 amps average (fifty percent duty cycle), and 500 circuilar mils per amp, then we should not use thinner than 6 gauge as based on the table.

Ch wazir (post # 8) gives specs which appear to be generated by a transformer calculator program. It states 11 gauge. This is based on 50% duty cycle through the transformer (because of its having a center tap). This gauge may very well be adequate, considering there will only be a few turns of it.

However there needs to be enough metallic mass to carry away the heat.

 

[nazeerhussain]

Thank you milind.a.kulkarni for reply and your technical advise.
Regards

 

[nazeerhussain]

Thank you very much ch wazir for your kind technical reply and providing detail transformer specification.I think provided information would make such a project easier to construct/ adjust/ maintain.
So nice of you.
Regards