Calculation of Battry for Industrial UPS

[Mimkhan]

If some one suggest 200 kw Industrial UPS ..Then how to calculate the battries size and what type of battry should install.???

 

[IRstuff]

Why don't you look at smaller UPS's and scale up what they specify?

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!

 

[BrianG]

200kW is a serious UPS: scaling up from smaller UPS may not be appropriate as smaller ones often use gel-cell lead acid. The most suitable battery technology will vary with the particular inverter float voltage which will determine the number of cells required. Without knowing the hold-up time required it is not really possible to suggest a particular battery technology or determine its physical size. One thing is certain: 200kW capability will have huge current requirement from the battery system at full load and will require serious busbars or cabling from the battery.

 

[ScottyUK]

Remember that a battery doesn't store power, it stores energy. Without knowing the time for which the battery must support the load it is impossible to even guess the battery capacity.

 

[sibeen]

A few things you need to know. Firstly is the UPS really 200 kW? Normally UPS systems are rated in kVA at a given power factor.

Variables that are required to work out the battery.

1. The rated power factor of the UPS. With a PF of 0.8 then the UPS needs to provide 160 kW.

2. The Inverter efficiency of the UPS.

3. The number of cells in the battery bank.

4. The battery autonomy required (back up time).

5. The end voltage of the battery.

So an example.

A 200 kVA UPS rated at 0.8 PF, efficiency of 93%, 210 battery cells (lead acid).

The power required by the load = 200 kVA x PF = 200 kVA x 0.8 = 160 kW.

The power required by the inverter (takes into account the efficiency) = 180 kW divided by 93% = 172 kW.

Now divide the power required by the number of battery cells - 172000W divided by 210 = 819 watts per cell.

You then need to look up battery tables, and knowing your autonomy time and your end voltage find a battery that suits. In this example if the autonomy time required was 10 minutes and the end voltage 1.7 volts per cell, then (picking a battery manufacturer at random) an Enersys SBS190F can provide 835.3 watts per cell for ten minutes down to 1.7 volts per cell, and would therefore be a decent pick for this application.

 

[sibeen]

The power required by the inverter (takes into account the efficiency) = 180 kW divided by 93% = 172 kW.

should read:

The power required by the inverter (takes into account the efficiency) = 160 kW divided by 93% = 172 kW.

 

[IRstuff]

200 kW for 10 minutes, which is typical of smaller UPS's translates to 33.3 kWh. A Tesla is supposedly equipped with a 55 kWh battery. So, aside from the nitty gritty details of power cords, just connect up a Tesla to the inverter. Now, obviously, one ought not discharge a Tesla battery in 10 minutes, since that would drastically degrade the capacity of the battery. But, conceptually then, having 48 Tesla batteries would allow a very reasonable discharge rate. Something in-between might be more practical.

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!