Intelligent substation based networked bus protection method for power distribution network

Abstract

The invention relates to an intelligent substation based networked bus protection method for a power distribution network. The method comprises the following steps: (1) when a bus is in a short circuit, branch interval protection units of an intelligent substation of the power distribution network discover dip of voltage between phases and current break, and bus protection is started; (2) each protection unit distinguishes power direction of the branch, releases a GOOSE message containing a computation result, acquires GOOSE messages of other intervals in short time and judges whether information is lost or not; (3) if information is not lost, a bus fault recognition matrix Pdir is constructed, a fault position is judged on the basis of a bus fault recognition criterion, a corresponding switch is tripped, and a fault is cleared; (4) is information is lost, a bus fault recognition matrix P'dir under information loss is constructed, a fault position is judged on the basis of a bus fault recognition criterion under information loss, a corresponding switch is tripped, and a fault is cleared. With adoption of the method, the problem of poor bus protection quickness of the power distribution network is solved, the fault position can still be recognized accurately even under the condition of power direction information loss, and protection reliability is improved.

Description

technical field [0001] The invention relates to the field of power system protection of distribution network intelligent substations, in particular to a method for protecting networked busbars of distribution network intelligent substations. Background technique [0002] In the 10kV ~ 35kV power network, often do not use a special busbar protection device, but use the backup overcurrent protection of adjacent components as the busbar protection, the fault removal time is longer, generally set to 1.0-1.5s. The number of outgoing lines on the low-voltage side of the substation is large, there are many devices, and switches and other equipment are frequently operated. The probability of bus failure is much higher than that of high-voltage buses; Damaged equipment will expand the area of ​​the accident and cause serious consequences. Therefore, it is becoming more and more important to adopt fast and effective busbar protection on the 10 / 35kV side busbars of important substatio...

AI Technical Summary

Problems solved by technology

[0003] For bus short-circuit faults, the current protection schemes often have certain limitations: bus protection generally adopts the principle of differential protection, and all electrical components on the bus need to form bus protection. Due to the large number of connected electrical components and complicated wiring, People are easy to touch by mistake, and the signal is also susceptible to interference

When the traditional centralized busbar differential protection scheme encounters this kind of problem, due to the limited information obtained, it is often impossible to make an effective judgment, which leads to misjudgment and malfunction of the busbar protection, and expands the scope of the accident.

[0004] The anti-current transformer saturation ability of busbar current differential protection is poor. Although it adopts various anti-current transformer saturation criteria and algorithms, the effect is not ideal in actual operation, and misoperation of busbar protection occurs from time to time.

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