The so-called uninterruptible power supply system is a device that can continuously supply power to replace the municipal power supply in case of power failure. Its power comes from the battery pack. Due to the fast response speed of electronic components, it can continue to supply power in 4 ~ 8 ms or no middle time at the moment of power failure.
Why use UPS?
At present, the mass supply system all over the world is AC power supply. An ideal AC power supply should meet the following conditions:
1. Frequency stability
2. Voltage stability (within 5%)
3. No harmonic distortion (5%)
4. No noise interference (in accordance with ieee587, FCC, CE and other standards)
5. Low output impedance.
As you can imagine, if the UPS system is not used today, when the power supply is abnormal, it will cause the computer to crash or even cause the hardware failure, and the maintenance cost will be unpredictable; the hardware failure can be eliminated by spending money, but what about the data in the hard disk? You can’t buy it if you have money, so buying an uninterrupted power system for your equipment is just like buying insurance. UPS system doesn’t act only when there is a power failure. The above-mentioned abnormal power supply includes low, high, sudden wave, noise and so on, which is enough to affect the power quality of the normal operation of the equipment. Therefore, the importance of UPS can be seen.
As an important peripheral of computer, UPS is very important in protecting computer data, ensuring the stability of power grid voltage and frequency, improving the quality of power grid, and preventing the harm of instantaneous power failure and accident power failure to users.
UPS has developed from the rotating generator in the 1960s to the static all electronic circuit with intelligent level, and it is still developing. At present, UPS generally refers to static UPS, which can be divided into backup, online interactive and online according to its working mode.
1. Backup UPS: when the power supply is normal, it directly supplies power to the load from the power supply. When the power supply exceeds its working range or power is cut off, it is converted to battery inverter power supply through the transfer switch. Its characteristics are: simple structure, small size, low cost, but the input voltage range is narrow, the output voltage stability accuracy is poor, there is switching time, and the output waveform is generally square wave
2. Online Interactive UPS: when the power supply is normal, the load is directly supplied by the power supply. When the power supply is low or high, it is output through the ups internal voltage stabilizing line after voltage stabilization. When the power supply is abnormal or power failure, it is converted to battery inverter power supply through the transfer switch. Its characteristics are: wide input voltage range, low noise, small size and so on, but there is also switching time
3. When the power supply of On-line UPS is normal, the power supply rectifies and supplies DC voltage to the inverter, and the inverter supplies AC to the load. When the power supply is abnormal, the inverter supplies energy from the battery, and the inverter is always in the working state to ensure uninterrupted output. It has the characteristics of wide input voltage range, no switching time and high output voltage stability and precision. It is especially suitable for the occasions with high power requirements, but the cost is high. At present, almost all the ups with power greater than 3KVA are online ups
According to the output capacity, UPS can be divided into small capacity less than 3KVA, medium and small capacity 3KVA ~ 10KVA, medium and large capacity more than 10KVA.
UPS can be divided into three types according to the input / output mode: single-phase input / single-phase output, three-phase input / single-phase output, three-phase input / three-phase output.
For users, the three-phase power supply is easy to distribute the municipal power and load, and each phase bears part of the load current. Therefore, the medium and high-power UPS mostly adopts three-phase input / single-phase output or three-phase input / three-phase output power supply mode.
Intelligent UPS is a major development trend of ups. With the application of ups in the network system, network managers emphasize that the whole network system is the protection object, hoping that the whole network system can continue to work without interruption when the power supply system fails. Therefore, it is a new trend for UPS to configure microprocessor to make it intelligent. The combination of hardware and software in UPS greatly improves the function of ups and can monitor the operation status of UPS, such as UPS output voltage frequency, grid voltage frequency, battery status and fault record. It can also detect the battery, discharge and charge automatically, and switch on and off remotely through software. Network managers can analyze the power supply quality according to the information and take corresponding measures according to the actual situation. When UPS detects the power grid interruption, UPS automatically switches to battery power supply. When the battery power supply capacity is insufficient, UPS immediately notifies the server to make preparations for shutdown, and automatically shut down before the battery runs out. The intelligent UPS communicates with the computer through the interface, so that the network administrator can monitor the ups, so the function of its management software is extremely important.