Longitudinal impedance-based T-shaped line protection and calculation method

A technology of longitudinal impedance and calculation method, which is applied in the direction of detecting faults, instruments, and measuring devices according to conductor types, and can solve the problems of transient saturation effects of current transformers and difficulties in setting current differential protection, so as to overcome misoperation and eliminate Phase-to-phase coupling, high reliability effects
CN106066451AInactive Publication Date: 2016-11-02XI'AN POLYTECHNIC UNIVERSITY
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
XI'AN POLYTECHNIC UNIVERSITY
Publication Date
2016-11-02
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a longitudinal impedance-based T-shaped line protection and calculation method which comprises the following steps: longitudinal impedance is calculated when internal faults and external faults occur in a T-shaped single phase line; the longitudinal impedance is analyzed under a three phase line model, and the longitudinal impedance is analyzed in a condition of current transformer transient saturation. Via use of the longitudinal impedance-based T-shaped line protection and calculation method disclosed in the invention, faults can be accurately and rapidly determined and effectively responded to after high tension transmission line faults occur, and a problem of difficult setting of a traditional current differential protection mode and specifically a problem that traditional current differential protection mode is susceptible to current transformer transient saturation can be overcome.
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Description

technical field

[0001] The invention belongs to the field of relay protection of AC transmission lines, in particular to a calculation method for T-type line protection based on longitudinal impedance. Background technique

[0002] With the development of the power system, more and more T-shaped transmission lines appear in high-voltage and ultra-high-voltage power grids. After a fault occurs, it is required that the protection can be quickly identified and acted effectively. However, due to the high transmission power and heavy load, once the T-shaped line fails, it will cause a large-scale power outage. Therefore, the protection of T-shaped high-voltage transmission lines has attracted more and more attention in recent years.

[0003] Although the current differential protection based on fault components can effectively avoid the influence of load flow, many schemes have been proposed on this basis. The differential protection scheme that takes the maximum value of the t...

Claims

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