Distributed power supply grid-connected and off-grid state detection method

Abstract

The invention provides a distributed power supply grid-connected and off-grid state detection method. In a power system with information and energy fusion, high-frequency carrier signals are transmitted by means of a power cable, so that information is exchanged among different power devices. The method is executed in the distributed power supply, and on-grid and off-grid states of the distributed power supply are judged based on demodulation and analysis results of carrier signals. The carrier model demodulation and analysis method relates to a BP neural network intelligent algorithm, and the grid-connected and off-grid state pattern recognition relates to a pattern recognition algorithm of a multi-dimensional membership function. The grid-connected and off-grid state detection algorithm provided by the invention is rapid, sensitive, accurate and reliable, theoretically has no island detection blind area, and also has no possibility of false operation.

Description

Technical field [0001] The present application relates to the field of power system protection and communication technology, and more particularly to a distributed power source and off-network state detection method. Background technique [0002] Distributed power supplies have a distinct running control policy or protection action in grid and away. Therefore, the distributed power supply needs to have the ability to accurately determine and off. However, existing judging methods are in special conditions, such as power matching, unable to determine the network state of the distributed power supply, forming a dislocation of the island to detect the blind zone; instead, but the grid encounters high-power load to generate frequency offset The traditional method may mistakenly believe that the distributed power supply is in the network state and generates an erroneous protection action. [0003] With the development of information energy fusion technology, there is more and more dis...

AI Technical Summary

Problems solved by technology

However, the existing determination methods cannot accurately determine the off-grid status of distributed power generation under special working conditions, such as power matching, forming a blind area for island detection; on the contrary, when the power grid encounters high-power load switching and frequency deviation , the traditional method may mistakenly believe that the distributed power generation is in an off-grid state, resulting in wrong protection actions

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