Method for distinguishing island phenomenon from grid-side voltage transient disturbance phenomenon

A grid-side voltage and transient disturbance technology, applied to AC network circuits, photovoltaic power generation, electrical components, etc., can solve problems such as operational conflicts and achieve practical and feasible results
CN112290585AActive Publication Date: 2021-01-29ZHEJIANG UNIV +2
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
ZHEJIANG UNIV
Publication Date
2021-01-29

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Abstract

The invention provides a method for distinguishing an island phenomenon from a grid-side voltage transient disturbance phenomenon. The method is suitable for a photovoltaic grid-connected system faultdetection technology. According to the method, change characteristics of a harmonic voltage before and after different faults are taken as a main basis, and the influence of main power grid background harmonic and spectrum leakage on harmonic detection is comprehensively considered. According to the method, a harmonic voltage threshold setting formula is specifically provided, the island phenomenon and the voltage transient disturbance phenomenon can be effectively distinguished, interference of frequency spectrum leakage and the main power grid background harmonic is avoided, and the methodhas practical feasibility.
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Description

technical field

[0001] The invention relates to a method for distinguishing the islanding phenomenon and the network side voltage transient disturbance phenomenon, which belongs to the fault detection technology in the field of new energy. Background technique

[0002] (1) The necessity of distinguishing the islanding phenomenon from the voltage transient disturbance phenomenon

[0003] When the photovoltaic grid-connected system fails, voltage drops will occur. There are two reasons for this phenomenon. One is that the grid-side short circuit breaker causes the system to be in an island state, and the other is that the system is still in the grid-connected state and the grid There is a transient disturbance in the side voltage due to other reasons. According to GB / T 19964-2012, IEEE Std.1547.1-2020 and other domestic and foreign standards (references [1-9]), when a point of common coupling (PCC) voltage drop is detected, the system needs to Perform island protection and l...

Claims

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