Detection method of islanding effects with reactive current disturbance based on amplitude changes and device thereof

A technology of amplitude change and island detection, applied in the direction of fault location, etc., can solve the problems of high cost grid side installation, and achieve the effect of avoiding current disturbance and ensuring power quality
CN102590713AActive Publication Date: 2012-07-18HUBEI TRESS TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
HUBEI TRESS TECH
Publication Date
2012-07-18

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Abstract

The invention provides a detection method of unintentional islanding effects with reactive current disturbance based on amplitude changes and suitable for a small wind-power or photovoltaic grid-connected inverter and a device of the detection method of the islanding effects with the reactive current disturbance based on the amplitude changes. The detection method does not need to change output work frequency and does not influence output current harmonic. The detection method has the advantages that (1) a method of reactive base wave current injection is utilized so that output of actual active power is not influenced, harmonic current is not generated, and quality of output electric energy is ensured; and (2) the amplitude of reactive current is changed periodically, the islanding effects are judged by judging voltage amplitude change conditions of connection points, and the condition that overlarge current disturbance is injected to meet needs of over-voltage or under voltage is avoided.
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Description

technical field

[0001] The invention relates to a detection method for grid-connected inverters to prevent unplanned islanding effects, in particular to a method for detecting islanding effects based on reactive current disturbances with amplitude changes and a device thereof. Background technique

[0002] The islanding effect is that when the power grid loses voltage, the grid-connected inverter still maintains the state of continuously supplying power to a certain part of the power grid. The island effect can be divided into unplanned island effect and planned island effect. The unplanned islanding effect is an unplanned and uncontrolled islanding effect, while the planned islanding effect is a planned islanding effect according to a pre-configured control strategy.

[0003] When the unplanned islanding effect occurs, due to the unknown power supply status of the system, it will cause the following adverse effects: 1. It may endanger the lives of grid line maintenance per...

Claims

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