The significance of UPS power supply to computer room

In the new technology of the world, computers have become one of the newest, most active and most advanced core technologies, and they are playing a powerful role in the information society. In the past decade, especially in recent years, computers have been widely used in all walks of life in China at an astonishing speed. From microcomputers to large and medium-sized computers, they are increasingly widely used in various fields such as office automation, data processing, communications, finance, and securities trading. In order to ensure the stable and reliable operation of these computers and the safety and accuracy of data, computer-specific UPS power supplies are being valued by people. More and more UPS power supplies are used in computer rooms , and some even call UPS power supplies the guardian of computers. Due to the rapid development of semiconductor technology, the application of large-scale integrated circuits, and driven by the widespread application of computers, UPS power supplies are also developing at an astonishing speed. China's UPS power supply production started late. In recent years, small UPS power supplies below 5kVA, especially 1kVA UPS power supplies, have made certain progress. This chapter mainly introduces the basic situation of UPS power supply from the following aspects, namely, why computers should be equipped with UPS power supply; the basic working principle of UPS; the market introduction of UPS power supply and how to select it; the installation, commissioning and use management of UPS power supply; and the knowledge about UPS special batteries. Why should UPS power supply be used ? The emergence of UPS power supply is closely related to the development of computers. It is very necessary for any electricity user to establish an uninterrupted power supply system. However, it is the result of the promotion of computer systems to build such a perfect uninterrupted power supply system. Why should computers be equipped with UPS power supply? Simply put, because the power supply quality of the city power grid is poor and cannot meet the power supply requirements of the computer system. Using UPS power supply is a technical measure to improve the power supply quality. "UPS" is the abbreviation of "Uninterruptible Power System" in English. It means "uninterruptible power supply system" or "uninterrupted power supply system". In other words, once the city power is lost (power outage), the backup power supply will continue to supply power to the original load almost without a breakpoint. UPS power supply is a very important device to ensure the normal operation of the computer. With UPS power supply, the computer can be guaranteed not to lose information and data, the safety of computer equipment can be guaranteed, and the disk surface or magnetic head will not be scratched. In other words, with the increasing popularity of computer applications and the continuous development of information processing technology, more and more stringent requirements are put forward for the quality of power supply. In the computers currently used in large quantities, their internal power supply systems are equipped with high-speed undervoltage protection circuits. When the power grid is undervoltage, the computer relies on the energy in the filter capacitor to maintain operation. Generally, it can be maintained for about 10ms. In order to avoid the loss of data in the memory, there must be a power supply that can re-send power in less than 10ms to ensure the normal operation of the computer system and process the information in the computer in time. This power supply is the so-called UPS power supply. In addition, some UPS power supplies also have a frequency stabilization function, which can solve the problem of excessive fluctuations in the voltage and frequency of the main power grid during normal power supply. Power outages are a common phenomenon in most parts of China. Some areas even have a three-day power outage to protect four days. The poor quality of power supply from the power grid is also very serious in some areas of China. Sometimes the voltage is too high, it can exceed 240V (phase voltage eight), and sometimes the voltage is too low, it can be lower than 180V. Under such power supply conditions, the computer system can basically not work normally. According to some information, in the industrially developed United States, although it can achieve an average of 8 years of power outage, the average outage is 1 minute. Moreover, under the condition of high power quality, computers are still widely powered by UPS power supply. In China, the power quality is poor, the power supply only has voltage and frequency standards, and there is no requirement for high-order harmonics. And there is a risk of power outage at any time, so it is very necessary to use UPS power supply in the computer power supply system. The standard of power supply quality in China is: large power grids above 4 million kW, voltage fluctuations are ±5%, frequency (50±0.2Hz); the voltage fluctuation of the power grid below 4 million kW is ±5%~-7% and the frequency is (50±0.5) Hz (there is no regulation for high-order harmonic components). In fact, in some areas, this standard is often not met, and power supply continues. Sometimes the voltage is so low that even fluorescent lamps can hardly start. Using UPS power supply can greatly improve the reliability of power supply. The backup power supply and the power supply currently supplying loads are phase-locked, that is, the same voltage, frequency, and phase. The power supply will not be interrupted when the power supply is switched, and no strong arc interference will be generated. The computer will not lose information and data, and the computer equipment, especially the hard disk, will not be scratched due to power outages. Use UPS power supply It can greatly improve the quality of power supply. UPS power supply is a purified power supply, which eliminates high-order harmonics and improves the quality of power supply. Although the waveform of the general mains voltage tends to be a sine wave, it has certain high-order harmonic components. The output voltage and frequency are affected and interfered by the nature, size, operation mode, input and removal of large loads, and faults of the load. The output voltage and frequency are very unstable, so it is difficult to meet the computer's requirements for power supply quality. Severe power supply instability will cause computer errors or information loss. In the UPS power supply, a quartz crystal oscillator is used to control the frequency of the inverter to remain constant. In addition, there is also a voltage automatic adjustment device with an accuracy of less than ±1. For the high-order harmonics before the 11th (some are 13th) harmonics, all can be filtered out, and the output is close to a sine wave. Thereby purifying the power supply and ensuring the normal operation of the computer.