Grid voltage drop detection method and system based on fuzzy interval dynamic look-up table

Abstract

The invention discloses a grid voltage drop detection method based on a fuzzy interval dynamic look-up table. According to the method, a grid voltage state is tracked in real time, a grid voltage waveform is drawn, a fuzzy interval criterion table is generated at the same time, and a sample voltage amplitude is compared with a value of a position corresponding to the criterion table by using the dynamic look-up table to judge whether the grid voltage drops. The method specifically comprises the following steps: S1, performing real-time monitoring and synchronous uploading of a grid voltage signal; S2, collecting and storing the grid voltage signal; S3, performing adaptive tracking detection on the grid voltage; S4, generating a voltage drop fuzzy interval criterion table; and S5, using thedynamic look-up table to judge whether the grid voltage drops. The invention further discloses a grid voltage drop detection system based on the fuzzy interval dynamic look-up table. The grid voltagedrop detection method and system disclosed by the invention are small in calculated amount, easy to implement and high in judgment speed, and effectively solves the problems of large calculated amount, poor instantaneity, susceptibility to harmonic interference and low application value of the conventional voltage drop detection methods.

Description

technical field [0001] The invention relates to the technical field of grid voltage detection, in particular to a grid voltage drop detection method and system based on a fuzzy interval dynamic look-up table method. Background technique [0002] There are many algorithms for voltage drop, and most of the common algorithms can accurately detect voltage drop, but there are problems that the response to voltage drop is not sensitive enough and the real-time performance is poor. Common detection methods for power grid voltage drop are effective value method and fundamental wave component method. In the past two years, there have been related researches using the method of continuous derivation of αβ transformation to detect power grid voltage drop. [0003] The effective value method calculates the effective value by sampling the instantaneous value of the voltage. By comparing the effective value of the voltage, it can be judged whether the grid voltage has dropped instantaneo...

AI Technical Summary

Problems solved by technology

In practical applications, the standard 220V sinusoidal AC reference frame without distortion is difficult to realize, so this method can only be used as a theoretical research, and cannot be used as a method for judging the voltage drop of the power grid in practical applications.

[0006] According to the analysis of common voltage sag detection methods, most of the common algorithms for grid voltage sag detection are proposed as theoretical research and cannot be really applied to actual devices.

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