Detection method of three-phase mains supply power failure

Abstract

The invention relates to a detection method of a three-phase mains supply power failure, wherein instant values of a three-phase mains supply voltages are sampled in real time, simple logic computation is carried out to the instant values of the three-phase mains supply voltages, and a voltage difference is obtained; and a correct threshold interval of the three-phase mains supply voltage is determined according an effective value of the three-phase mains supply voltage, and whether the voltage difference stays within the threshold interval is determined in order to quickly determine whether the three-phase mains supply voltage is powered off. The invention provides a method for quickly and reliably detecting mains supply abnormities, wherein whether the power failure or a default phase happens to a mains supply can be quickly determined through the simple computation based on real-time sampling of the mains supply voltages.

Description

technical field

[0001] The invention relates to the field of abnormal detection methods of electric power sources, in particular to a detection method for three-phase mains power failure. Background technique

[0002] The static switching switch in the uninterruptible power supply system is usually in the working state of the main power supply. When the main power supply is abnormal (such as power failure, phase loss), the static switching switch quickly switches to the working state of the backup power supply. Therefore, how to quickly and accurately detect AC The input source is powered off and the detection time is reduced as much as possible, which are the technical points and difficulties in the application of static transfer switches. If the detection time is too long, it will cause the load to stop working; if the detection is too fast, it is easy to make a misjudgment, resulting in frequent switching of the main and standby power supplies, reducing the service life o...

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