Battery calculations usually have two methods1 constant current mode calculation:
According to the principle of energy conservation, the configuration of the battery is calculated as follows:
C = (PL×T) / (vbat×η×K)
Among them: C - battery capacity, (AH) PL-UPS output power (W); T-battery backup time (h);
VBAT-battery pack voltage (VDC),η-UPS battery inverter efficiency (0.90-0.95, selected by model).
K-battery discharge efficiency (coefficient).
K 's choice follows:
K
Discharge time<1h
1
2
4
> 8h
Battery discharge efficiency
0.6
0.7
0.8
0.9
1
According to the calculation result, determine the AH number of the battery, select the appropriate configuration according to different brand batteries.
For example, a brand new generation rack-type high-performance small capacity UPS-ITA series 6kVA, battery pack voltage 192V (16-section 12V power supply series), UPS battery inverter efficiency 0.94, 4.8KW is filled, 2 hours calculation
C = 4800 * 2 / (192 * 0.94 * 0.7) = 76ah (estimated value) Select 12V85AH battery 16, such as C & D12-76LBT.
2 constant power calculation formula
W = PL÷(N * 6 *η(Watts / Cell)
Among them, the PL is the active power (kW) of the UPS rated output; N is 12V battery number; VF is the rated voltage of the battery pack,ηInverter efficiency.
That is, the power required for the unit cell is calculated first, and then the constant power discharge table provided by the battery manufacturer can look for the battery model that can meet the requirements.
The termination discharge voltage is determined according to 1.75V / Cell. Usually the power table given by the battery manufacturer is the power of the monomer 2V / Cell, defined as Watts / Cell.
Some of the power table given by the manufacturer is Watts / Block, then multiply the coefficients.
For example, a brand new generation rack-type high-performance small capacity UPS-ITA series 20kVA, battery segment 32 sections (30-40 rod-upless sections adjustable), UPS battery inverter efficiency 0.95, press full load 20kva * 0.9 = 18kW, the backup 2 hours calculation.
W / Cell = PL / (N×6×η) = 18000 / (32 * 6 * 0.95) = 98.68Watts / Cell
C & D's MPS series 12-76 discharge power surface is shown in Figure: 2 hours of discharge power is 51.5W / Cell at 1.75VDC, select 98.68 / 51.5 = 1.92 groups, take 2 groups of 32 sections 12V76AH C & D MPS series battery, Total 64 Festival.
(Source: UPS application) Recommend: LiFePO4 Battery Manufacturer Energy storage battery Manufacturer Integrated machine energy storage battery series Manufacturer Lead lithium battery Manufacturer Outdoor Backup Battery Manufacturer Portable outdoor power supply Manufacturer Power battery Manufacturer Powerwall LiFePO4 Battery Manufacturer Battery rack Manufacturers Telecom LiFePO4 Battery Manufacturer Wall mounted battery storage Manufacturer China Lifepo4 Battery
