high vdc input inverter

Discussion in 'General Electronics Chat' started by kenbker, Jul 25, 2011.

  1. kenbker

    Thread Starter New Member

    Jul 25, 2011
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    any body know where i could get a curciut for a 240Vdc to 240Vac inverter? or buy such a device off the shelf...thanks
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    Is this battery powered? What's the input voltage range? What's the power ratings?
     
  3. kenbker

    Thread Starter New Member

    Jul 25, 2011
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    yes battery powered, 240v dc in, 3kw
     
  4. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    What's the input voltage range? Minimum to maximum? Or is the voltage always going to stay on exactly 240V? Batteries discharge.
     
  5. kenbker

    Thread Starter New Member

    Jul 25, 2011
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    240vdc +-10%
     
  6. RRITESH KAKKAR

    Senior Member

    Jun 29, 2010
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    A 3KW UPS is not an easy task to build, I have 5KVA UPS which uses 15 battery of 12V current is 26 Amps-h. the size of that UPS is also big with LCD display on it which indicates Voltages freq.,etc....

    Inside it there were 2 or 3 IGBT (Insulated Gate Bipolar Transistor) with big PCB (circuits) the transformer used in UPS were many. one was of big size i don't know the rating and few were for sensing the output voltage something like this..!!
    and capacitor of 10,000uf of 440V which was very big and dangerous ....
     
  7. tom66

    Senior Member

    May 9, 2009
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    240VDC is not equivalent to 240VAC even if you swap polarity 50 times a second. You need a 330VDC input due to how AC works, it's 330Vpk (and 660Vpk-pk)
     
  8. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    I used to work in a company where we developped DC/AC converters with three different input voltage ranges (and they where only 2,5kVA). It took us 3 years to develop it from scratch.

    As stated before you need to convert the input DC to a higher intermediate DC voltage and then pass it through the inverter to get your AC (if the inverter has an output inductor / no transformer).
    If you don't want to make a double conversion using the DC you have you could generate AC directly from it and then put a transformer at the output. Although, for 3kW at 60Hz this transformer will be H.U.G.E!

    So if you need a fast and reliable solution I guess it's better to buy one off the shelf. There are UPS's and telecom DCAC converters that could fit your needs.

    example: http://www.gamatronic.co.il/DCACInverters.aspx?prod=70
     
  9. RRITESH KAKKAR

    Senior Member

    Jun 29, 2010
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    That's very cool, I want to see that UPS ..........!!
    and the link has very heavy UPS 200KVA nice one UPS.
     
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