Three online modes of UPS power supply

UPS power supplies can be divided into three types according to their working principles: backup type, online type and online interactive type.

(1) Online UPS power supply

Online UPS power supply: This UPS power supply keeps its inverter in working state all the time. It first converts external AC power into DC power through the circuit, and then converts DC power into high-quality sinusoidal AC power through a high-quality inverter to output to the computer. The main function of the online UPS under power supply conditions is to stabilize voltage and prevent radio interference; when there is a power outage, the backup DC power supply (battery pack) is used to power the inverter. Since the inverter is always working, there is no problem of switching time, which is suitable for occasions with strict requirements on power supply. A major advantage of the online UPS power supply is that the power supply lasts for a long time, generally for several hours, and sometimes up to more than ten hours. Its main function is to allow you to work as usual in the event of a power outage. Obviously, due to its special function, the price is obviously much more expensive. This online UPS is more suitable for industries such as computers, transportation, banking, securities, communications, medical care, and industrial control, because computers in these fields generally do not allow power outages.

(2) Online interactive UPS

Online interactive UPS power supply: This is an intelligent UPS power supply. The so-called online interactive UPS means that when the input mains power is normal, the UPS inverter is in reverse working (i.e., rectification working state) to charge the battery pack; when the mains power is abnormal, the inverter immediately switches to the inverter working state to convert the battery pack power into AC output, so the online interactive UPS also has conversion time. Compared with the backup UPS, the online interactive UPS power supply has stronger protection function, the inverter output voltage waveform is better, generally a sine wave, and its biggest advantage is that it has strong software functions, which can easily access the Internet, and perform remote control and intelligent management of the UPS. It can automatically detect whether the external input voltage is within the normal range. If there is a deviation, the voltage can be stepped up or down by the voltage stabilizing circuit to provide a relatively stable sine wave output voltage. Moreover, it can communicate with the computer through a data interface (such as RS-232 serial port). Through the monitoring software, users can directly monitor the power supply and UPS status from the computer screen, simplifying and facilitating management work, and improving the reliability of the computer system. This type of UPS combines the advantages of high efficiency of backup UPS and high power supply quality of online UPS, but its frequency stabilization characteristics are not very ideal and is not suitable for long-delay UPS power supply.

(3) Backup UPS

Backup UPS power supply: It is usually in the battery charging state. When the power is off, the inverter switches to the working state urgently, converting the DC power provided by the battery into a stable AC output. Therefore, the backup UPS is also called an offline UPS. The advantages of the backup UPS power supply are: high operating efficiency, low noise, and relatively cheap price. It is mainly suitable for occasions where the mains power fluctuation is not large and the power supply quality is not required. It is more suitable for home use. However, this UPS has a switching time problem, so it is not suitable for use in critical places where power supply cannot be interrupted. But in fact, this switching time is very short, generally between 2 and 10 milliseconds, and the computer's own switching power supply should be able to maintain about 10 milliseconds when the power is off, so personal computer systems generally do not have problems due to this switching time. The backup UPS can generally only provide power for a few minutes to tens of minutes, mainly to give you time to back up data and finish the work at hand as soon as possible, and its price is also relatively low. For computer applications that are not too critical, such as individual home users, a low-power backup UPS can be equipped.