DC to AC conversion

[Scarr]

OK the internet is great but sometimes there is TOO MUCH info out there

I want to calculate the power I would have using a bank of DC batteries after conversion to AC, so if I had a bank of batteries totalling 240Vdc 55Ah what power would be available in Kwh, I was going to write my attempt at this here but decided not to as I think I have it totally wrong!!!


Steve

 

[mvs sarma]

you have to evaluate the load on the AC generated in KVA and divide by power factor of your load and also of the convertor used by you.
Get KW. multiplying the derived KW by Hours (presuming the the battery is giving same voltage. you get KWH. As this is impracticable to keep battery constant at a known ,
voltage, and the fall of voltage causes increase of load current in DC to ac converters, you have to take an integral value or , i feel weighted average could also approximately help.
Yes, it is complicated.

 

[Reloadron]

In theory a 240 volt battery rated at 55 Amp Hour would be able to deliver 13.2 KW for 1 hour. That would also be 26.4 KW for 1/2 hour. The power is the Voltage X the Current the Amp Hour rating is in theory how long a battery will deliver the rated current so a 240 volt battery rated at 55 Amp Hours will deliver 55 Amps at 240 Volts for 1 Hour. That would be 240 X 55 = 13,200 Watts for 1 hour. In reality you won't see that. Depends on battery type, temperatures and other variables.

Oh and I see mvs sarma posted while I slowly typed. I only looked at DC with a purely resistive load. Now enter everything else mentioned and things get complicated.

Ron

 

[mvs sarma]

The OP has named the post as DC to AC conversion. it is thus obvious that the poster expects some sort of inverter device.
IMHO, the AH rating of such batteries is generally at 10 hr rating. means , if you discharge at 5.5amps load , it serves 10 hours,
if you draw 55 amps it would not work for 1 hour. it might work for around 6 to 7 hours and later it won't, as the efficiency of battery falls.