UPS working principle

Regarding the working principle of UPS, many people should have a vague concept, it is not very clear, what is the specific working principle. And for users who use UPS, it is necessary to understand how it works. Today, I will introduce the knowledge about UPS working principle in detail here.

The working principle of UPS uninterruptible power supply is simple and simple, and it is not difficult to say. Let ’s take Shank Power as an example to briefly talk about its working principle:

AC-DC conversion: The AC power from the power grid is stepped down by an autotransformer, full-wave rectified, and filtered into a DC voltage and supplied to the inverter circuit. The AC-DC input has a soft-start circuit, which can avoid the impact on the power grid during startup.

    DC-AC inverter circuit: It adopts a high-power IGBT module full-bridge inverter circuit, which has a large power margin, has a particularly small output impedance in the output dynamic range, and has fast response characteristics. Due to the use of high-frequency modulation current limiting technology and fast short-circuit protection technology, the inverter can work safely and reliably regardless of power supply voltage transients or load shocks or short circuits.

Control drive: Control drive is the core to complete the function control of the whole machine. In addition to providing detection, protection, synchronization, and various switching and display drive signals, it also completes SPWM sine pulse width modulation control. Due to the use of static and dynamic dual voltage feedback . Greatly improved the dynamic characteristics and stability of the inverter.

Schematic: 

But UPS power supplies include three types, online , backup and online interactive . Each type of UPS has different working principles. Here we take online and backup as examples to talk about their working principles.

The working principle of the on-line UPS is that after the input mains power is rectified and filtered, it becomes a pure 50Hz, 220V AC voltage output after being inverted; on the other hand, the charger outputs DC power to charge the battery pack. The battery pack is converted into 220V, 50Hz AC power output by the inverter circuit, and it automatically converts in zero time, which effectively guarantees uninterrupted power output, comprehensively resolves power failures in city power, and provides high-level power protection. For the protection of critical systems and important data, it is widely used in data centers, large networks, and industrial systems (finance, post and telecommunications, hospitals, power, aerospace, military, etc.)

The backup UPS is directly output by the bypass switch when the mains power is supplied. Only when the mains power is cut off, the battery pack is inverted by the inverter circuit to an AC circuit output of 220V, 50Hz. It is most suitable for protecting a single PC or workstation. It can solve three major faults of common power failures for you, including: power interruption, voltage sag and voltage surge.

    The working principle of UPS is roughly the same as above. For a detailed understanding of it, users need to understand it through the user manual and product introduction or the explanation of the merchant. After all, this is only theoretical knowledge, and practice yields true knowledge.