Distribution network protection and automatic device cooperating method based on DG characteristics

Abstract

The invention discloses a distribution network protection and automatic device cooperating method based on DG characteristics. According to the method, action levels are divided into a fault isolation level, a spare power automatic switching intercutting DG level and a low-frequency low-voltage intercutting partition islet level in space, whether an islet is allowed to operate or not is determined according to the balance capacity of DG local loads, and fast islet division is achieved automatically through a low-frequency low-voltage intercutting fixed value to guarantee stable operating of a power system and reliable operating of the local loads. Meanwhile, a protection fixed value considers that even though DG is in an islet operating state and breaks down, a protection device can act fast and accurately to remove the fault. Regional information is adopted as coordinating factors and is used for overcoming the defects of separation of a relay protection and automatic device and a DG operating work condition, division of the islet extending layer by layer is determined according to the trend distribution of a power source and loads after fault current removing and the changes of a network topology structure, and a coordinating distribution type power source protection scheme system is formed.

Description

technical field [0001] The invention relates to a method for coordinating distribution network protection and automatic devices based on DG characteristics. Background technique [0002] With the promotion of renewable energy, distributed generation (DG) has become an important form of power source. With the access of DG, the power distribution system is no longer a single power supply network. A large number of generators and loads exist at the same time. Compatibility with the reclosing and standby switching devices. When a fault occurs, after the protection isolates the fault, if there is a selective "selection" of the cooperation relationship between the protection action and the automatic device, it can maintain the power supply of DG to the local users to the greatest extent, so as to provide effective support for the power grid after the fault. And it is beneficial to the DG grid-connected operation after the power grid returns to normal working conditions, which ha...

AI Technical Summary

Problems solved by technology

The existing coordination relationship between protection and automatic devices is calculated off-line, facing the radiative pure load network of DG, or the DG is disconnected after a fault to return it to the radial load network, and the existing protection and protection are maintained. Automatic device cooperation relationship, this method obviously cannot effectively improve the utilization rate of distributed power

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