Computer room Engineering-on-line, Backup UPS selection (reprint)

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1 backup UPS or on-line ups?

As an important protective measure of equipment in computer room, UPS plays an irreplaceable role. There are a wide variety of ups in the market, in the final analysis, there are two categories: back-up and on-line. Back-ups prices are relatively inexpensive, and online ups prices are much higher, and many high-power ups are online, then what is the difference between the choice of which ups? Let's start with a simple analysis of how the two work.

Before analyzing the UPS principle, we need to know two kinds of parts:

1, Rectifier: The role is to convert alternating current to DC power.

2, inverter: Contrary to the rectifier, the function of the inverter is to convert the DC to alternating current, but the structure is much more complex.

A brief analysis on the principle of 2 backing UPS

Backup ups when normal operation, the switch is connected to the input and output power, that is, the device directly uses the mains, while the rectifier and voltage converter for the battery charge, the inverter is in a non-working state. When the mains voltage is abnormal or power off, the switch will automatically switch to connect the battery and the inverter, when the battery and the inverter began to work, output power to the output, at the same time issued a warning prompt.

Switch switching time is generally a few milliseconds to 10 milliseconds, the impact on computer equipment is not small, but the first time to switch the output of alternating current waveform is square wave rather than sine wave, so for some of the high power supply quality requirements of the equipment may have some impact. There is also an online interactive UPS power supply, in fact, the essence is a backup ups of a strengthened version, the normal work of its inverter is in standby state, online interactive UPS using intelligent control, the clutter filter is better, the output voltage waveform is basically sine wave, However, there is still a switching time when switching to battery power after mains power is switched off.

Let's look at how the online ups works.

3 on -line UPS principle Analysis

On-line UPS is also called double-transform ups, we can see that the mains power after rectifier rectifier into a direct current, a part of the battery charge, the other part is directly sent to the inverter for the inverter, the direct current to the AC output, when the mains problems, the battery will provide electricity to the inverter, Ensure the continuous output of the power, and alarm prompt. Because of its "AC----DC----AC" two times the transformation, so called double transform ups.

Looks like this kind of design seems some superfluous, actually, because after the voltage two times conversion, not only the power conversion rate is high, and the output voltage quality is very high, no clutter, can meet the power requirements of the more demanding equipment, in fact, double transformation of this technology has not been considered fresh, many of the electrical appliances around us ( The core part of the power supply, including the computer, is the dual-transform circuit, the so-called switching power supply. Because the inverter is always working, so this kind of power supply does not have so-called "switching Time", that is, the output is always a stable voltage output, there will be no square wave voltage appears, to ensure the output voltage stability. However, in the practical application, in consideration of the inverter part of the sudden problem, the online ups will often increase the road bypass mains as an emergency standby, once the inverter fails, the switching switch will switch to the standby mains line, of course, this situation occurs very small probability.

4 on-line ups, future trends

Tell the basic working principle of the two, then we summarize the advantages and disadvantages of the two: backup UPS production cost is low, the price has a great advantage, but it in the power conversion time and a certain amount of clutter, the basic use of small power, the response is not very sensitive to the situation, it is more suitable for office and home.

On-line ups in itself without problems can be achieved "0 switching time", and the voltage output smooth without clutter, so more suitable for use in the computer room and data center, and now the online UPS also support self-test, information display and software remote monitoring functions, now the high-power ups are online, But also according to the application of custom-made for example, cabinet, rack style and so on. The disadvantage is that the price is more expensive, but now some manufacturers have started to introduce low-cost online ups, and even do a split design, the host and battery separation, users can configure the number of batteries to regulate power and control costs. So, in the long run, buying an online ups is a smart choice.

Computer room Engineering-on-line, Backup UPS selection (reprint)