Improved Fourier algorithm applied in the high-voltage complex protection apparatus

After analyzing the existing problems of the current flameproof switchgear when realizing the complex protection actions, that is decaying DC component can not be filtered by using traditional full-cycle Fourier algorithm while decaying DC component disturbance effection works, and also the protection will fail to operate or unwanted operate. An improved Fourier algorithm is presented in this paper, in this way the decaying DC component and high harmonic are all completely filtrated. The block diagram of the device structure is also presented. The experimental device shows that this method is reliable and accurate and has a small computation capacity. The simulation and running results all validate itpsilas feasible.