The composition and principle of traditional UPS in data center power supply system

Static UPS is divided into online and backup types. The structures of these two types of UPS are roughly the same, and their main structures include rectifier (charger), battery, inverter and conversion switch. The difference between the two is the different working methods: the inverter of the online UPS is working from beginning to end, while the inverter of the backup UPS is started only when the power supply is abnormal.

Traditional UPS Principle

Traditional battery UPS power supply System principle

When the mains supply is normal, the AC input is converted into DC 100% through AC/DC conversion, which charges the battery on the one hand and supplies power to the inverter on the other hand; the inverter is in working state from beginning to end, converting the DC voltage into AC voltage through DC/AC to supply power to electrical equipment.

Rectifier: The AC mains input is converted into DC power by the rectifier to charge the battery and supply power to the load through the inverter.

Inverter: This inverter is a DC-AC unidirectional inverter. When the mains is available, it obtains power from the rectifier and then sends it to the output end, ensuring that high-quality power is provided to the load; when the mains is off, the battery supplies power to the load through the inverter.

Static switch: Under normal circumstances, it is disconnected on the bypass side and turned on on the inverter side. When a fault occurs in the inverter circuit, or when the load is impacted or overloaded by a fault, the inverter stops outputting, the static switch turns off on the inverter side, turns on the bypass side, and the grid directly supplies power to the load.

Advantages of traditional UPS

First, the double conversion UPS has excellent electrical characteristics: due to the use of AC/DC and DC/AC dual conversion design, it can completely eliminate any impact from any voltage fluctuation, waveform distortion, frequency fluctuation and interference from the mains power grid.

Second, compared with other types of UPS, this type of UPS can provide stable frequency and voltage power to the load, so the power supply quality is obviously superior;

Third, when the mains power is lost, the output voltage is not affected in any way and there is no switching time;

Fourth, the devices and electrical designs are mature and widely used;