Research on Electrified Railway Harmonics Detection Based on Sliding-window Iterative DFT Algorithm

Abstract

Harmonic detection is a key link in the electrification railway harmonic suppression. Detection precision directly affects the effect of filter. And only accurately detect the harmonic, reasonable inhibition can be conducted. This paper analyzes the shortcomings of the present stage of harmonic current detection methods, such as a large amount of calculation and requirement low pass filtering link. For electrified railway harmonic characteristics in accordance with the active power filter harmonic detection real-time, accuracy requirements, an iterative discrete Fourier transform method for sliding windows is proposed. Simulation results show that the iterative discrete Fourier method of sliding-window for harmonic analysis can accurately detect traction's load current base wave and every harmonic current component. In the case of traction load mutations, the algorithm can also in a power frequency cycle accurately track changes of load current and the harmonic detection current real-time.