Line and bus protection method based on initial fault angle, transition resistance and machine learning

Abstract

The invention relates to a line and bus protection method based on initial fault angle, transition resistance and machine learning. A lot of high-frequency transient signals are generated by line faults, most of the high-frequency transient signals are passed by ground distribution equivalent capacitance of a bus when passing the bus, and the higher the frequency is, the more the signals are passed by; high-frequency components generated under different initial fault angles and different transition resistances differ a lot; the fault feature, initial fault angle, transition resistance and fault area label of a typical fault sample are used to form an input vector sample set of machine learning to train machine learning; and machine learning after training is used for fault determination. A corresponding protection motion value is set for differential fault conditions, adverse influence of the initial fault angle and the transition resistance is eliminated, the protection reliability is greatly improved, and error caused by setting the protection motion value manually is prevented. Only the typical fault sample rather than fault samples under all fault conditions is needed, the training load of machine learning is reduced, and the method is feasible practically.

Description

technical field [0001] The invention relates to the protection technology of power grid transmission lines and busbars, in particular to the intelligent protection method of transmission lines and busbars based on transition resistance, fault initial angle and machine learning by using fault transient information. The proposed method is suitable for high voltage and ultra-high voltage and UHV power grid line and busbar protection. Background technique [0002] At present, the protection widely used in the transmission network is mainly based on the power frequency variation as the fault characteristic protection, and the protection action generally takes 20-40ms. At the same time, the protection based on the power frequency electric quantity change is easily affected by the distributed capacitive current of the transmission line. , current transformer saturation, power system oscillation and transition resistance and other factors. With the continuous development of the pow...

AI Technical Summary

Problems solved by technology

This protection method is very novel, but there are still defects and deficiencies. For example, when judging the fault, it still adopts the traditional fault action value setting method. For different fault conditions (different fault initial angles, transition resistance) The same setting value is used for all faults, but the values ​​of the fault characteristics after reduction under different fault initial angles and transition resistance conditions are quite different, and it is difficult to achieve the desired effect. The reduction accuracy needs to be further improved in order to better eliminate faults The influence of initial angle and transition resistance on protection, in order to further improve protection reliability and protection sensitivity

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