According to its working principle
UPS power supply can be divided into three types: backup type, online type and online interactive type.
(1) Backup UPS
Usually in the battery charging state, when the power is cut off, the inverter switches to the working state urgently, and converts 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 fluctuation is not large and the quality of power supply is not high. However, this UPS has a switching time problem, so it is not suitable for use in places where the critical power supply is not always interrupted. However, in fact, the switching time is very short, usually between 2 and 10 seconds, and the switching power supply of the computer itself should be able to maintain about 10 seconds when the power is turned off, so the personal computer system generally does not suffer from this switching time. And there is a problem. The backup UPS can only last for a few minutes to dozens of minutes, mainly to give you time to back up data and end the work at hand as soon as possible, and its price is also low. For computer applications that are not too critical, such as individual home users, a low-power backup UPS can be configured.
(2) Online UPS
This UPS keeps its inverter in working condition. It first converts external alternating current into direct current through the circuit, and then converts the direct current into high-quality sine wave alternating current through a high-quality inverter and outputs it to the computer. The main function of the online UPS in the power supply situation is to stabilize the voltage and prevent the interference of radio waves: in the event of a power failure, the backup DC power supply (battery bank) is used to supply power to the inverter. Since the inverter is always working, there is no switching time problem, which is suitable for occasions with strict requirements on power supply. One of the advantages of online UPS different from backup type is that the power supply lasts for a long time, usually a few hours, but also as large as 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 functions, the price is obviously a lot more expensive. This kind of online UPS is more suitable for computer, transportation, banking, securities, communication, medical, industrial control and other industries, because computers in these fields generally do not allow power outages.
(3) Online interactive UPS
This is an intelligent UPS. The so-called online interactive UPS means that when the input mains is normal, the inverter of the UPS is in reverse operation (ie, rectification working state) to charge the battery pack; when the mains is abnormal The inverter immediately changes to the inverter working state, and converts the battery pack energy into AC output, so the online interactive UPS also has a conversion time. Compared with the backup UPS, the online interactive UPS has stronger protection function, and the output voltage waveform of the inverter is better, generally a sine wave, and its biggest advantage is that it has strong software functions, which can easily access the Internet and conduct Remote control and intelligent management of UPS. It can automatically detect whether the external input voltage is within the normal range. If there is any deviation, it can be boosted or stepped down by the voltage regulator circuit to provide a relatively stable sine wave output voltage. And it can communicate with the computer through the data interface (such as S-232 serial port). Through the monitoring software, the user can directly monitor the power supply and UPS status from the computer screen, which simplifies and facilitates the management work, and can improve the computer system. reliability. This kind of UPS concentrates the advantages of high efficiency of backup UPS and high power quality of online UPS, but its stable
The frequency performance is not very ideal, and it is not suitable for UPS power supply with constant delay.
