Frequency feedback disturbance-based island detection method and apparatus

A technology of island detection and frequency feedback, applied in the fault location and other directions, can solve the problems of easy missed detection, affecting power quality, increasing system harmonics, etc., to shorten the time and reduce the detection blind area.
CN104111406AActive Publication Date: 2014-10-22河南许继电力电子有限公司 +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
河南许继电力电子有限公司
Publication Date
2014-10-22

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Abstract

The invention relates to a frequency feedback disturbance-based island detection method and apparatus. The method comprises the following steps: a preliminary determination step; to be specific, detecting a power grid parameter and determining whether an island state occurs preliminarily; a disturbance step; to be specific, if so, adjusting a frequency difference between a frequency of a phase-locked loop output and a power grid frequency by a PI controller, using the frequency difference as an reactive current input reference value iq*+ and outputting the value to an reactive current control link; and a secondary determination step; to be specific, detecting the power grid parameter again and determining whether an island effect occurs truly. According to the invention, the passive island detection and the active island detection are combined, thereby reducing the detection blind area of the inverter and detecting the island phenomenon occurrence accurately and rapidly. Moreover, manual disturbance of the frequency and phase and the like does not exist in the method and no harmonic waves are introduced in the power grid, thereby reducing the influence on the total harmonic wave content of the inverter output current by the island detection algorithm.
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Description

Technical field

[0001] The invention relates to a method and device for detecting islanding based on frequency feedback disturbance. Background technique

[0002] With the increasing pressure on the global resources and environment, energy conservation, emission reduction and resource conservation have become the trend of world economic development, focusing on the development of a green economy and strengthening energy conservation and emission reduction, and accelerating the construction of a resource-saving and environment-friendly society" On. Electric energy is a widely used energy source, and its application has penetrated into all aspects of industrial production, society and people’s lives. At present, the power generation system composed of new energy is represented by wind and solar grid-connected power generation; if this distribution network exists With the grid-connected power generation system, the distributed power supply will continue to supply power to the distri...

Claims

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