The principle of uninterruptible power supply (UPS) for power supply

UPS is the abbreviation of Uninterruptiable Power Supply, which has evolved from the rotating generator in the 1960s to the current static all-electronic circuit with a certain degree of intelligence. It has also become increasingly mature with the rapid development of electronic technology, especially power devices and automatic control technology.

　　What we often come into contact with is a backup power supply device used in computer applications to protect data loss due to accidental power outages. It can provide power for a certain period of time to ensure safe shutdown when the AC power is disconnected.

　　The basic functions are: when the mains power is interrupted, it can provide uninterrupted power supply; always provide high-quality AC power to the load, achieve voltage stabilization, frequency stabilization, suppress surges, peaks, electrical noise, compensate for voltage sag, long-term low voltage and other factors. Dynamic UPS consists of an engine and a generator set . It relies on the AC mains to drive the AC motor to rotate, thereby driving the coaxial AC generator and the inertia flywheel to rotate at the same speed, and the generator supplies power to the load. When the mains power fluctuates, the inertia flywheel does not respond to the interference after a short-term voltage mutation, ensuring the stability of the output voltage; when the mains power is cut off, the inertia of the flywheel extends the rated voltage supply for another 5 seconds, because the data information is saved. Later, it developed into an internal combustion engine UPS system, but this type of UPS is large in size, noisy and inefficient, and is not widely used at present. At present, the most commonly used UPS is still the static UPS. The UPS generally referred to now also refers to the static UPS, but the concept should be clearly distinguished.

　　Dynamic UPS is rarely used, so most people usually refer to static UPS as UPS. Static UPS can be divided into three categories according to the power supply mode: online UPS (ON-LINE), backup UPS (or offline, OFF-LINE/BACK-UP) and online interactive (LINE-INTERACTIVE).

　　The application of uninterruptible power supply (UPS) in power system has become more and more widespread. With the popularization and application of power automation equipment such as power communication, unattended substation, and microcomputer monitoring, the power system has put forward higher requirements for uninterruptible power supply. Although power plants have two power supply lines, this cannot guarantee that important loads such as computers can be powered without interruption. To ensure the power supply indicators of information equipment such as microcomputers, an uninterruptible power supply (UPS) must be used.