The content of this note reveals the questions of how and why the Fourier transform known to all power engineers works. Here we tried to refrain from using a complex conceptual apparatus, all the calculations used should be clear to anyone who has somehow mastered the initial level of the university course in higher mathematics. For all others, it is possible that the material presented is intuitive.

# Tag: Fourier transform

Fourier transform, Fourier filter, Fourier transform in simple words, Fourier in relay protection.

## Windowed Fourier Transform

Consider the effect of the window Fourier transform on the operation of distance protection.