mobile | classic
Dataweek Electronics & Communications Technology Magazine





Follow us on:
Follow us on Facebook Share via Twitter Share via LinkedIn


Search...

Electronics Buyers' Guide

Electronics Manufacturing & Production Handbook 2019


 

UPS battery configuration made easy
28 August 2019, Power Electronics / Power Management

Determining the UPS (uninterruptible power supply) battery configuration using a formula can be quite complicated and, since many users are not very familiar with it, a more simplified method can be used to speed up the process and thereby save time.

This is typically done in the pre-planning phase before designing the practical application solution. The battery configuration can be quickly and simply calculated based on the UPS output load and the required backup time. The formula is as follows:Required battery capacity (Ah) = UPS capacity (kVA) x 109 (Ah/cell) + kVA + number of battery blocks per group

Example 1

As an example, consider a 130 V d.c. system of 120 kVA operating a UPS with 32 cells in series per bank, and requiring a backup time of 60 minutes. The required battery capacity is:

120 kVA x 109 Ah (cell/kVA) = 13 080 Ah (total requirement)

13 080 Ah / 32≈409 Ah

Therefore, if using a 12 V, 100 Ah battery bank x 4, there is a choice between using 32 cells per group, in which case the actual backup time will be less than 60 minutes, or 33 cells per group, resulting in a backup time of slightly more than 60 minutes.

If the required backup time is 30 minutes, then:

120 x 109 = 13 080 Ah

13 080 / 32≈409 Ah (for 60 minutes)

409 / 2≈205 Ah

However, since the discharge power and discharge time of the battery are not linear, simply dividing by 2 is incorrect; rather, a modified coefficient must be used (see Table 1). Therefore, in this case, 205 x 1,23≈252 Ah, so one option could be 4 banks (32 cell/bank) of 12 V, 65 Ah battery.

If the backup time requirement is 20 minutes, then:

120 x 109 = 13 080 Ah

13 080 / 32≈409 Ah (for 60 minutes)

409 / 3≈136 Ah

136 x 1,41 (modified coefficient) 192 Ah

Therefore, one option could be 3 banks (32 cells/bank) of 12 V, 65 Ah batteries.

Example 2

Consider a 126 Ah/cell/kVA system, of 120 kVA UPS with 32 cells per bank. If the required backup time is more than one hour you also need to consider the modified coefficient in the calculation (see Table 2).

If the required backup time is 3 hours, then:

126 x 120 = 15 120 Ah

15 120 / 32≈472 Ah

472 x 3 = 1 416 Ah (for 3 hours)

Then divide it by a modified coefficient as 1 416 / 1,25≈1 133 Ah

The option of 4 banks of 12 V, 300 Ah batteries can therefore be selected.

According to the principle of energy conservation, the above method is the same for three-phase/single-phase or single-phase/single-phase UPS. Generally, high-power UPS systems are equipped with 32 batteries per battery pack and the number of parallel batteries should not exceed 4 so as not to affect the current sharing and charging effect of the battery pack.

However, the above is a simplified method that is only a rough calculation where the result which is not completely accurate. To obtain a more accurate result, one will also need to consider the parameters of the equipment, the requirements of the application, the power grid condition and the power conversion efficiency.

For more information contact Forbatt SA, +27 11 469 3598, sales@forbatt.co, www.forbatt.co/index.php


Credit(s)
Supplied By: Forbatt SA
Tel: +27 11 469 3598
Fax: +27 11 469 3932
Email: sales@forbatt.co
www: www.forbatt.co/index.php
  Share on Facebook Share via Twitter Share via LinkedIn    

Further reading:

  • Rugged DC-DC converters
    28 August 2019, Vepac Electronics, Power Electronics / Power Management
    XP Power introduced two new series of wide input-range chassis- and DIN-rail mount DC-DC converters that offer simple and rapid installation into a wide variety of industrial and ITE applications. The ...
  • Power controller for smart home appliances
    28 August 2019, RF Design, Power Electronics / Power Management
    Qorvo has introduced a new intelligent power control solution for reducing energy consumption, bulk, weight and noise in smart home appliances, AC-powered fans and compressors. This mixed-signal system-in-package ...
  • Bidirectional laboratory power supply
    28 August 2019, Vepac Electronics, Power Electronics / Power Management
    EA Elektro-Automatik’s new 30 kW EA-PSB 10000 is a bidirectional power supply with a working efficiency of up to 96%, both as a source and as a drain with energy feedback. The device can be switched from ...
  • 3 Watt DC-DC converters
    28 August 2019, Avnet South Africa, Power Electronics / Power Management
    Aimtec has introduced three new series of switching regulators – the AMSRB1-78JZ, AMSRL1-78JZ and AMSRL-78JZ – all meeting the EN62368 standard and suitable for IoT (Internet of Things) applications. The ...
  • Isolated PFC module
    28 August 2019, Conical Technologies, Power Electronics / Power Management
    SynQor has added a new isolated PFC (power factor correction) module to its AeroQor range of products for the airborne electronics market. Featuring highly efficient active power factor correction, the ...
  • DC-DC converter for DIN-rail mounting
    28 August 2019, Vepac Electronics, Power Electronics / Power Management
    MTM Power is offering the HSD series of primary switched DIN-rail modules with DC input voltage. The devices offer an input voltage range of 20 - 72 V d.c. and allow efficient solutions for different ...
  • DC UPS for DIN-rail mounting
    31 July 2019, Vepac Electronics, Power Electronics / Power Management
    The Effecta DCH series power supplies with UPS function are suitable for a variety of applications, and their robust IP 20 housing is applicable for all DIN-rail applications. With its power boost mode, ...
  • 80 V buck driver for LEDs
    26 June 2019, Altron Arrow, Power Electronics / Power Management
    Infineon Technologies’ new LED driver, the ILD8150/E, features an innovative hybrid dimming mode technology for achieving 0,5 percent of the target current. With its supply voltage range from 8 V up to ...
  • AC-DC power supplies for medical devices
    26 June 2019, Vepac Electronics, Power Electronics / Power Management
    XP Power has announced two new ranges of AC-DC power supplies that provide BF class insulation for healthcare applications where ehnanced EMC performance is a key requirement. The PBR500 and PBR650 ...
  • N-channel enhancement mode FET
    26 June 2019, Electrocomp, Power Electronics / Power Management
    Diotec Semiconductor’s 2N7002 is a widely used small-signal MOSFET in SOT-23 package. With an RDS(on) of maximum 2 Ω, the component offers a lower on-state resistance than the common industry standard. ...
  • Digitally controlled power supply
    26 June 2019, Vepac Electronics, Power Electronics / Power Management
    XP Power’s nanofleX series of configurable, modular, digitally controlled AC-DC power supplies is constructed in a compact, low-profile 1U mechanical chassis format that suits today’s space constrained ...
  • Adaptive LED current ripple suppressor
    26 June 2019, Altron Arrow, Power Electronics / Power Management
    Diodes Incorporated announced the availability of the AL5822 LED current ripple suppressor, which provides high levels of ripple suppression while maintaining high power factor for commercial and industrial ...

 
 
         
Contact:
Technews Publishing (Pty) Ltd
1st Floor, Stabilitas House
265 Kent Ave, Randburg, 2194
South Africa
Publications by Technews
Dataweek Electronics & Communications Technology
Electronics Buyers’ Guide (EBG)

Hi-Tech Security Solutions
Hi-Tech Security Business Directory

Motion Control in Southern Africa
Motion Control Buyers’ Guide (MCBG)

South African Instrumentation & Control
South African Instrumentation & Control Buyers’ Guide (IBG)
Other
Terms & conditions of use, including privacy policy
PAIA Manual





 

         
    Classic | Mobile

Copyright © Technews Publishing (Pty) Ltd. All rights reserved.