Mar 13, 2021
8 reasons to use UPS and EPS in detail
We all know that the city electricity drives most of our electricity load and satisfies our daily work, life and study. But in factories, computer rooms (weak and strong motor rooms), power distribution cabinets, and even in some homes, EPS power supplies and UPS power supplies are used. Many people know that uninterrupted power is very good, but why EPS power supplies and UPS power supply is so popular?
Is the utility power really continuous and constant? Why use UPS power supply?
1. There is a surge in the circuit: it means that the effective value of the output voltage is higher than 110% of the rated value, and the duration is one or several cycles. The surge is mainly due to the high voltage generated by the sudden unloading of the power grid when the large electrical equipment connected to the power grid is shut down.
2. High-voltage spike: refers to a voltage with a peak value of 6000v and a duration from one ten thousandth of a second to one-half of a cycle (10ms). This is mainly caused by lightning strikes, arc discharges, static discharges or switching operations of large electrical equipment.
3. Transient overvoltage: Refers to a pulse voltage with a peak voltage of up to 20000V but a duration between one millionth of a second and one millionth of a second. The main reason and possible damage are similar to high-voltage spikes, but there are differences in the solutions.
4. Voltage sag: refers to the low voltage state where the effective value of the mains voltage is between 80% and 85% of the rated value, and the duration is one to several cycles. Starting large equipment, starting large motors, or connecting large power transformers may cause this problem.
5. Wire noise: Refers to radio frequency interference (RFI), electromagnetic interference (EFI) and various other high-frequency interference. The operation of the motor, the operation of the relay, the operation of the motor controller, broadcast transmission, microwave radiation, and electrical storms all cause line noise interference.
6. Frequency deviation: Refers to the change of the mains frequency exceeding 3 Hz. This is mainly caused by the unstable operation of the emergency generator, or by the power supply with unstable frequency. 7. Continuous low voltage (brownout) means that the effective value of the mains voltage is lower than the rated value and lasts for a long time. The reasons for this include: large-scale equipment startup and application, main power line switching, large-scale motor startup, and line overload.
8. Mains power interruption: refers to the situation where the mains power is interrupted and lasts for at least two cycles to several hours. The reasons for this are: circuit breaker tripping on the line, mains supply interruption, and grid failure.
We all know that once the power is cut off in some occasions or special equipment, even for a few seconds, the equipment loss and economic loss caused are inestimable. Therefore, EPS power supply and UPS power supply have been produced in accordance with the times, and they are widely used. !
Detailed explanation of UPS working conditions
In terms of basic application principles, UPS is a power protection device that contains energy storage devices, uses inverters as the main components, and stabilizes voltage and frequency output. It is mainly composed of rectifier, battery, inverter and static switch.
1. Rectifier: A 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 transforms alternating current (AC) into direct current (DC), which is filtered and supplied to the load, or to the inverter; second, it provides charging voltage to the battery. Therefore, it also acts as a charger at the same time;
2. Battery: A battery is a device used by UPS to store electrical energy. It is made up of several batteries in series, and its capacity determines the time it takes to maintain discharge (power supply). Its main functions are: 1 When the mains power is normal, it converts electrical energy into chemical energy and stores it inside the battery. 2 When the mains power fails, the chemical energy is converted into electrical energy and supplied 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 is composed of inverter bridge, control logic and filter circuit;
4. Static switch: Static switch is also called static switch, it is a kind of non-contact switch, it is an AC switch composed of two SCRs in reverse parallel connection, and its closing and opening are controlled by the logic controller. control. Divided into two types: conversion type and parallel type. The transfer type switch is mainly used in a two-way power supply system, and its function is to realize automatic switching from one way to another; and the parallel type switch is mainly used for paralleling inverters with mains or multiple inverters.