Analysis of the influence of the window used in the Short-Time Fourier Transform for High Impedance Fault detection

A study on the length and type of the window function used in the Short-Time Fourier Transform (STFT), along with its suitability to extract the harmonic content from a High Impedance Fault (HIF) current is presented on this paper. Additionally, a method to detect HIF based on the phase angle of the third harmonic current is developed. The proposed algorithm performance is evaluated by two database: one containing HIF simulated signals and other containing actual HIF oscillographic records. This paper presents the current state of this research, and, so far, the method is able to detect HIF occurring in different types of surfaces (wet and dry), as well as it is insusceptible to typical noises present in the real oscillograms.