Uninterruptible Power Supply system

Uninterruptible power supply system (also known as uninterruptible power supply or non-stop power supply), referred to as UPS. It is a power protection device that contains energy storage devices, with inverters as the main units, and outputs voltage and frequency stabilization. Usually, uninterruptible power supplies are mainly composed of battery packs, rectifiers and inverters, static switches and other parts. Electric energy is stored in the battery in the form of direct current (DC), which enables the uninterruptible power supply to output voltage to the outside in the event of an external power failure. Therefore, the uninterruptible power supply has the function of purifying power supply and providing uninterruptible power supply. It is now widely used in computer security, transportation, aerospace, medical, industrial control and other fields.

A. What is an uninterruptible power supply system:

Uninterruptible power supply system (also known as uninterruptible power supply or non-stop power supply), referred to as UPS. It is a power protection device that contains energy storage devices, with inverters as the main units, and outputs voltage and frequency stabilization.

1. In principle: an uninterruptible power supply is a power electronic device that integrates digital and analog circuits, automatic control inverters and maintenance-free energy storage devices.

2. In terms of function: the uninterruptible power supply can effectively purify the mains power when there is an abnormality in the mains power supply; it can also provide backup power for computers and other devices for a certain period of time when the mains power supply is suddenly interrupted, so that you have ample time to deal with it;

3. In terms of use: With the advent of the information society, uninterruptible power supplies are widely used in various links from information collection, transmission, processing, storage to application, and their importance is increasing with the increasing importance of information application.

During normal operation, the AC voltage input by the external power supply enters the uninterruptible power supply system through the input isolation switch, and the battery is continuously charged through the charging circuit. At the same time, the AC/DC circuit converts the AC voltage into DC voltage, and then the inverter inverts the DC voltage into AC output, which is supplied to the load through the output isolation switch; when the external power supply input is interrupted, the backup battery starts to work, and the battery voltage is converted into AC output through the inverter, and supplied to the subsequent load through the output isolation switch; when the uninterruptible power supply inverter fails or is overloaded, the uninterruptible power supply will directly output the input power to the load through the bypass switch to ensure uninterrupted power supply.

B. Composition of uninterruptible power supply system:

From the basic application principle, the uninterruptible power supply system is a power protection device with energy storage device, inverter as the main component, and stable voltage and frequency output. It is mainly composed of rectifier, battery, inverter and static switch.

1. Rectifier: The rectifier is a rectifier device, which is simply a device that converts alternating current (AC) into direct current (DC). It has two main functions: first, it converts alternating current (AC) into direct current (DC), supplies the load or inverter after filtering; second, it provides charging voltage to the battery. Therefore, it also acts as a charger;

2. Battery: The battery is a device used by UPS to store electrical energy. It is composed of several batteries connected in series, and its capacity determines the time it maintains discharge (power supply).

C. The main functions of the uninterruptible power supply system are:

1. When the city power is normal: convert electrical energy into chemical energy and store it inside the battery.

2. When the mains fails: convert chemical energy into electrical energy and provide it to the inverter or load;

3. Inverter: In layman's terms, an inverter is a device that converts direct current (DC) into alternating current (AC). It consists of an inverter bridge, control logic and filter circuit;

4. Static switch: A static switch is also called a static switch. It is a contactless switch. It is an AC switch composed of two thyristors (SCRs) connected in reverse parallel. Its closing and opening are controlled by a logic controller. It is divided into two types: conversion type and parallel type. Conversion type switches are mainly used in systems with two power supplies. Their function is to achieve automatic switching from one to another; parallel type switches are mainly used to connect inverters in parallel with the mains or multiple inverters.