Abstract:

Abstract:In order to detect the current transformer(CT) disconnection quickly and accurately and at the smae time to improve the reliability of the
protection bus,the wave about the CT break and bus failure were analyzed.A project was put forward based on the characteristics of the current variation.This scheme combines the Fourier algorithm with sampling point algorithm,which not only maintains the advantage of the Fourier algorithm,but also increase the velocity of the sampling point algorithm.The CT disconnection can be judged in a short time.The scheme can ensure that the bus can’t be falsely tripped under the CT disconnection and line break can’t be misjudged at the bus failure.

Key words: Keywords:bus protection, sampled values algorithm, fourier algorithm, sample point algorithm