What is its working principle and application scope

First, what is UPS ? What is its working principle and application scope?
Uninterruptible power supply ( UPS ) is a kind of power supply equipment that can keep its load equipment from external power system interruption for a period of time.
With the continuous development of digital computer technology, its application has gradually penetrated into industrial control, banking, power, military, financial, communications and other important departments, which also puts forward more stringent requirements for the stability and reliability of computers. The emergence of UPS is to cope with the sudden power outage, voltage instability, power line clutter* and other problems that often occur in the power system, to ensure that the computer system can continue to work normally when the power supply problems arise.
UPS works like a reservoir. When the external power supply is normal, UPS will not only supply power to the load normally, but also convert part of the electric energy into chemical energy to store. Once the external power supply is suddenly interrupted, UPS will immediately start the inverters, which will rapidly convert the chemical energy into electrical energy to supply power to the load continuously, so as to ensure the normal work of the load equipment. Do.

1. How to Choose an UPS Power Supply Suitable for You
   According to the statistics of 86ups.com, a global professional UPS power data website, there are as many as 20 UPS power brands in the market, totaling 1643 UPS power products. Faced with so many kinds of UPS power products, which one is more suitable for you?
2. How to Choose Online and Backup UPS Power Supply
   Generally, online UPS has a high price, but its protection function is very perfect. It can filter out all kinds of viruses parasitic on the vast majority of power grids and fully guarantee the stability and safety of load equipment. Backup UPS has a small volume and low price, and can also prevent data loss caused by power failure for some equipment systems that are not particularly important. No problem.
   If economic conditions permit, of course, first online UPS. But from an economic point of view, a backup UPS power supply is enough for ordinary families, or ordinary office space with low requirements.
3. Choose what capacity of UPS power supply is adequate
   At present, the average power consumption of a computer is about 250 VA, and a backup 500 VA UPS can provide about 10 minutes of power for it. This period of time has fully guaranteed that you have enough time to save the files, and then shut down the computer normally. There are many computers at home that can calculate the total power by themselves, and then select the appropriate UPS capacity. For some special commercial and industrial applications, the calculation is much more complicated. Because these departments often require UPS to ensure that dozens of computers can work for more than ten hours or even tens of hours without power supply.
   UPS Battery Charging and Discharging Knowledge
   I. About Charging
4. When UPS is floating charging, please charge it with constant voltage or current below 0.002CA at a charge voltage of 2.275V/cell (set at 20 C). When the temperature is below 0C or above 40C, it is necessary to modify the charging voltage. With 20C as the starting point, the single cell voltage changes – 3MV with each change of one degree.
5. When cycling charging, the charging voltage is 2.40-2.50V/cell (the setting value at 20 C), and the charging voltage is constant. When charging at temperatures below 5C or above 35 C, starting at 20 C, the charging voltage is adjusted to -4mv/cell for each change.
6. The initial charge current is controlled below 0.25CA.
7. Charging capacity is set to 100-120% of discharge capacity, but when the ambient temperature is below 5C, it is set to 120-130%.
8. The lower the temperature (below 5C) is, the longer the charging end time is, the higher the temperature (above 35C) is, the more likely it is to be overcharged. Therefore, it is better to charge within 5C-30C, especially in cyclic use.
9. In order to prevent overcharging, install charging timer as far as possible, or automatically convert to Trickle-flow charging mode.
10. When charging, the temperature of the battery should be controlled in the range of – 15C to + 40C.
    II. ON DISCHARGE
    When discharging, the temperature of the battery should be controlled in the range of – 15 -+50%.
    Continuous discharge current should be controlled below 3CA (H below 6CA).
    The discharge termination voltage varies with the magnitude of the current, as described below. Note that when amplifying, the voltage should not be lower than the following voltage.
    Please charge quickly after discharging. If discharged carelessly, please charge immediately.
    III. Installation Notes
    When installing batteries, the following must be observed:
11. Do not install batteries near the sealed space or fire, otherwise there is a risk of explosion and fire.
12. Don’t cover the battery with ethylene film which may cause static electricity. Sometimes it will cause explosion when static electricity is generated.
13. Do not install batteries in places where water is likely to enter. Otherwise, there is a risk of electric shock and fire.
14. Do not install batteries in the environment of – 40 C~60 C.
15. Do not use batteries where there is dust, otherwise it may cause short circuit of batteries.
16. When putting the battery into the box, we should pay attention to the air circulation.
17. Do not press the upper cover with sticky or labeled objects. Because there is an exhaust valve under the upper cover, the gas generated in the battery will not escape.
18. When the number of parallel connection is floating charging, the plug-in terminal batteries can only be connected with three rows. There is no special restriction on bolted terminals, but the number of connection is small and the reliability increases. In addition, in parallel connection, it is necessary to consider making the connection conductor and contact resistance equal between the columns. In order to keep the charge and discharge batteries in balance, the actual use should not exceed three columns.
19. When using batteries with different capacities, new and old, and manufacturers with different batteries, it is possible to damage batteries and machines because of their different characteristics, so please avoid using them.
    IV. On custody
20. When keeping, please note that the temperature should not exceed – 20 ~40 ~C.
21. Batteries must be kept in full charge when they are in storage. Since some capacity will be lost due to self-discharge during transportation or storage period, please make up the power supply when using.
22. For long-term storage, in order to compensate for self-discharge during storage, please make a supplementary call. Storage over 40C has a bad effect on battery life, please avoid!
23. Keep in a dry, low temperature and well ventilated place.
24. If the battery packaging is improperly wetted by water during storage or transfer, the packaging carton should be removed immediately to avoid the water-wetted carton becoming a conductor and causing battery discharges or burning positive extremities.
    V. Daily Inspection and Maintenance
25. Check batteries regularly. If dust and other external contamination are found, please clean the batteries with water or cloth soaked in warm water. Do not use gasoline, banana water and other organic solvents or oils for cleaning, in addition, please avoid the use of chemical fiber cloth.
26. When the total voltage or the indicator value of the voltmeter on the indicator panel deviates from the benchmark value shown in the table below (+0.05V/cell) during floating charging, the reasons should be investigated and handled.