Detection method and detection system of input phase loss

Abstract

The invention discloses a detection method for input phase loss and a detection system thereof. Three-phase line voltage information of a three-phase power grid flows through a line voltage detection circuit, and a frequency converter collects the three-phase line voltage information and stores the three-phase line voltage information. The time point corresponding to the information; the inverter will step down the collected three-phase line voltage information and output the three-phase line voltage information; the processor module obtains the three-phase line voltage information through the conditioning circuit; according to the obtained three-phase line voltage information, the second voltage vector angle information is obtained by sorting and calculating; according to the first voltage vector angle information and the second voltage vector angle information, the frequency information of the three-phase power grid is sorted and calculated, and the frequency information is output; The frequency information of the three-phase power grid is used to detect and judge whether the three-phase power grid has input phase loss. The invention has strong detection sensitivity and high accuracy, and improves the safety coefficient of protecting the three-phase power grid.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to an input phase loss detection method and a detection system thereof. Background technique [0002] During the high-voltage and complex working process of the three-phase power grid, it is easy to cause three-phase phase loss, which will damage the rectifier bridge. If the phase loss fault is not detected in time or it takes a long time to detect and eliminate it, it will damage the relevant power equipment and cause economic damage. Property damage was severe. [0003] The traditional detection method for the lack of phase of the three-phase power input by the inverter is generally to calculate the unbalance degree according to the amplitude of the three-phase phase voltage. If the unbalance degree exceeds the set threshold, it is judged that the input phase is lacking. The amplitude of the amplitude changes with a sinusoidal law. It takes a long time to judge the unba...

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Problems solved by technology

[0002] During the high-voltage and complex working process of the three-phase power grid, it is easy to cause three-phase phase loss, which will damage the rectifier bridge. If the phase loss fault is not detected in time or it takes a long time to detect and eliminate it, it will damage the relevant power equipment and cause economic damage. severe property damage

[0003] The traditional detection method for the lack of phase of the three-phase power input by the inverter is generally to calculate the unbalance degree according to the amplitude of the three-phase phase voltage. If the unbalance degree exceeds the set threshold, it is judged that the input phase is lacking. The amplitude of the amplitude changes with a sinusoidal law. It takes a long time to judge the unbalance degree detection. The maintenance and repair personnel fail to find the fault in time. The detection sensitivity is poor, which has a large potential safety hazard. The influence of voltage fluctuations leads to a decrease in detection accuracy and poor reliability

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