The working principle and use requirements of UPS uninterruptible power supply

In some occasions with high load level requirements (Class 1 load), the commonly used power supply is UPS (Uninterruptible Power Supply), that is, equipment that cannot be powered off, such as communication systems; computer systems; monitoring systems; DCS systems; operating rooms of medical systems ; Important electric valves in the industry, etc. Now the UPS uninterruptible power supply sockets are also common in hospital wards and hotels. It can be said that UPS is used more and more widely.


The composition and working principle of UPS

UPS generally consists of rectifier, battery, inverter, static switch and control system. Usually an online UPS is used. It first converts the AC power input from the mains into a regulated DC power supply, supplies the battery and the inverter, and then turns it into a stable, pure, high-quality AC power supply through the inverter. It completely eliminates any power problems (voltage fluctuations, frequency fluctuations, harmonic distortion and various disturbances) that may occur in the input power supply

The functional requirements of the new power UPS

1. The switching time of the static bypass switch is generally 2~10ms, and should have the following functions:

a. When the inverter device fails or needs to be repaired, it should be switched to the power grid (mains backup) power supply in time.

b. When the branch circuit is suddenly short-circuited and the current exceeds the predetermined value, it should be switched to the power grid (city backup) power supply to increase the short-circuit current and make the protection device act quickly. After the fault is removed, start and return to the inverter to supply power.

c. Uninterruptible power supply devices with frequency tracking limit link, when the frequency of the grid is passive or the voltage fluctuation exceeds the rated value, it should be automatically disconnected from the grid, and automatically connected to the grid when the frequency and voltage return to normal.

2. When using the mains bypass, the frequency and phase of the inverter should be synchronized with the mains lock.

3. For the negative unbalance of the three-phase output, the difference between the fundamental wave root mean square current of the largest one-phase and the smallest one-phase load should not exceed 25% of the rated current of the uninterruptible power supply, and the maximum line current should not exceed its Rated value.


Manly Battery Co.,Ltd specializes in providing energy storage power, UPS backup power, power supply and new energy system solutions and operation and maintenance services for new energy, electric wheels, smart energy storage and green power applications. Among them, the field of network energy mainly includes communications, power, data centers, financial securities, rail transit, etc.; the field of smart energy storage mainly includes household energy storage, industrial and commercial energy storage, and microgrid energy storage systems; the field of green power mainly includes forklifts, low-speed electric vehicles, off-road vehicles, etc. At present, the main products are lithium-ion batteries and systems, lead acid battery replacement lithium batteries and systems, and new energy system integration products and services. Please contact: [email protected]