Uninterruptible electric power supply system and method

Abstract

The invention relates to an uninterruptible electric power supply system which outputs multiple redundant voltages in interruption of power supply equipment. The uninterruptible electric power supply system comprises a common bus and a plurality of UPS (Uninterruptible Power Supply) devices, wherein the common bus collects the multiple redundant voltages and enables the redundant voltage with a highest voltage value to act as a dominated voltage, each UPS device detects the redundant voltage thereof and judges whether a power recovery signal from the power supply equipment is received or not, and if so, each UPS device enables the redundant voltage thereof to present a descending trend, and increases or decreases the redundant voltage thereof according to a comparison result of the dominated voltage and the redundant voltage thereof in the descending trend. Therefore, the redundant voltage of each UPS device dynamically follows the dominated voltage continuously, so that voltage disturbance caused by asynchronous turn-off of the redundant voltage in power recovery is avoided, and thus the stability and the reliability of the power supply are improved.

Description

technical field [0001] The present invention relates to a system and method for emergency or backup power supply, in particular to an uninterruptible power supply that avoids the voltage disturbance caused by asynchronous shutdown of the backup power supply when the power is restored, thereby increasing the stability and reliability of the power supply. Supply systems and methods. Background technique [0002] refer to figure 1 , DC type uninterruptible power supply device (hereinafter referred to as DC type UPS device) is a device that electrically connects an AC / DC power supply 11 and a load 100, and the AC / DC power supply 11 receives an AC mains power and converted into a DC power, which is supplied to the load 100 via a DC bus 13, and the main purpose of the DC UPS device is to receive the DC power storage in advance when the mains power is in normal operation. When the mains power is abnormal, such as a power outage, the DC UPS device will replace the AC and DC power ...

AI Technical Summary

Problems solved by technology

[0004] However, if the DC UPS device 121 and the DC UPS device 122 cut off the output backup voltage instantaneously, it will cause voltage disturbance on the DC bus 13; in addition, the DC UPS device 121 and the DC UPS device 121 The UPS device 122 cannot know that the mains power is restored at the same time, so that the DC UPS device 121 and the DC UPS device 122 are as follows: figure 2 As shown, the timing of shutting off the output power is inconsistent, which will easily worsen the voltage disturbance of the DC bus 13, and cause the instantaneous load of the DC UPS device 121 and the DC UPS device 122 to be too large. Therefore, how to improve the existing uninterruptible power supply The lack of power supply technology is a problem that needs to be solved urgently

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