A method to prevent the impact of current sampling abnormal data on current protection

Abstract

The invention discloses a method for preventing influence of current sampling abnormal data on current protection. According to the method, the square of a chord length between two sampling points is calculated according to the fact that normal sinusoidal waveform sampling points are continuous and sampling data of a cycle wave is equivalent to points, continuously distributed according to a sampling frequency, on a round with a radius being a current effective value and according to the characteristic that the chord length of the same included angle of the round is fixed and unchanged; the calculated chord length is fixed and unchanged when the sampling point is normal; the calculated chord length is changed and continuous analysis is performed when data of the sampling point changes; the chord length cannot be returned to a normal value if the calculated chord length is changed caused by a fault current, and the calculated chord length can be still recovered to the normal value if the calculated chord length is charged caused by abnormal sampling point; and the fact whether corresponding current protection is opened or not is decided according to a judgment result. The method is simple, and the false action on the current protection caused by abnormal data of the sampling point can be effectively prevented.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a method for preventing misoperation of current protection when current sampling data is abnormal. Background technique [0002] With the improvement of the voltage operation level of traditional substations and the corresponding improvement of the electromagnetic environment level, the electronic components of the relay protection device are more likely to be interfered, which may cause some normal sampling data to be distorted. Electronic transformers and merging units are commonly used in smart substations, and the stability and reliability of these devices will have a direct impact on digital relay protection. Under normal operating conditions, these electronic devices will also cause data transmission distortion of individual normal sampling points due to their own components or other interference in the substation. The distorted data is somet...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art, to provide a method to prevent the impact of current sampling abnormal data on current protection, to solve the impact on current protection caused by the abnormal current sampling point data of existing relay protection, and to prevent Misoperation of current protection when there is no fault in the grid

Images