How to choose UPS power supply

What is UPS?

UPS－Uninterrupted Power System； A type of energy conversion device that uses battery chemical energy as backup energy to continuously provide (AC) electrical energy to user equipment in the event of power outages or other grid failures.

Why use UPS?

The four major functions of UPS: 

1. Non power outage function, solving the problem of power outages in the power grid;

2. Communication voltage stabilization function to solve the problem of severe fluctuations in network voltage;

3. Purification function, solving the problem of power grid and power pollution;

4. Manage functions to solve communication power maintenance issues.

The main functions of UPS

1. Implement isolation between the power grid and electrical appliances;

2. Realize uninterrupted switching between two power sources;

3. Provide high-quality power supply;

4. Voltage and frequency conversion functions;

5. Provide backup time after power outage.

UPS type

According to different working principles, UPS is divided into offline (backup UPS, interactive UPS) and online UPS

According to different power supply systems, UPS is divided into: single in single out UPS, three in single out UPS, three in three out UPS

According to different output power, UPS is divided into: micro<6kVA, small 6-20kVA, medium 20-100kVA, large>100kVA

According to the position of the battery, UPS is divided into: battery built-in UPS (standard model) and battery external UPS (long delay model)

According to different operating modes of multiple machines, UPS can be divided into series hot backup UPS (for small and medium power machines) (source: communication power technology), alternating series hot backup UPS (for small and medium power machines), direct parallel UPS (for medium and large power machines)

According to the characteristics of transformers, UPS is divided into high-frequency UPS (high-frequency machine) and power frequency UPS (power frequency machine)

According to different output waveforms, UPS is divided into: square wave output UPS step wave (quasi sine wave) UPS sine wave output UPS

UPS system structure and principle

The basic principle of UPS is that when there is mains power, the mains power is directly supplied to the load through a switch, and the inverter does not work; In addition, the mains power charges the battery through a charger. After a power outage, start the inverter and supply the energy stored in the battery to the load through the inverter and switch. Power level around 0.25-2KVA

The operating principle of interactive UPS is that the main difference between online interactive UPS and backup UPS is that the inverter and charger are combined into one; Output is achieved through tap switching of the transformer to achieve segmented voltage regulation. (Source: Communication Power Technology) Power level around 0.7-20kVA

The operating principle of online UPS is that regardless of whether the grid voltage is normal or not, the AC voltage used by the load must pass through the inverter circuit, which is always in working condition. Power level of around 0.7-1500kVA

UPS power supply system

A complete UPS power supply system consists of front-end power distribution (mains, generator, distribution cabinet), UPS host, battery, back-end power distribution, and additional back-end monitoring or network monitoring software/hardware units.

UPS monitoring system

UPS network monitoring system=intelligent UPS+network+monitoring software 

Network monitoring software includes the following three parts: SNMP card monitoring console software Security shutdown program UPS monitoring network.