From a basic application principle perspective, a UPS is a power protection device containing an energy storage unit, with an inverter as its main component, providing stable voltage and frequency output. It mainly consists of a rectifier, battery, inverter, and static switch.
1) Rectifier: A rectifier is a device that converts alternating current (AC) to direct current (DC). It has two main functions: first, converting AC to DC, which is then filtered and supplied to the load or the inverter; second, providing charging voltage to the battery. Therefore, it also functions as a charger.
2) Battery: The battery is used by the UPS to store electrical energy. It consists of several batteries connected in series, and its capacity determines the duration of discharge (power supply). Its main functions are: 1. When the mains power is normal, converting electrical energy into chemical energy and storing it inside the battery. 2. When the mains power fails, chemical energy is converted into electrical energy to supply the inverter or load;
3) Inverter: An inverter is a device that converts direct current (DC) into alternating current (AC). It consists of an inverter bridge, control logic, and filter circuits;
4) Static switch: A static switch, also known as a stationary switch, is a contactless switch. It is an AC switch composed of two silicon controlled rectifiers (SCRs) connected in reverse parallel. Its closing and opening are controlled by a logic controller. There are two types: transfer type and parallel type. Transfer type switches are mainly used in systems powered by two power sources, and their function is to achieve automatic switching from one power source to another; parallel type switches are mainly used to connect inverters in parallel with the mains power or multiple inverters.
