The invention discloses a single-phase grounding fault wire
selection method based on improved HHT. According to the method, a zero sequence
current sensor is mounted at each output line in a
system close to a
bus end, a zero sequence current of each line is acquired in real time, when the zero sequence current
signal surpasses a threshold, sampling data is stored; traveling wave signals of the stored data are filtered, a maximum value point and a minimum value point are rapidly acquired according to rules that inherent
system oscillation frequency and
high frequency signal amplitude satisfy index attenuation, initial values of three-times
batten interpolation function coefficients are selected, an improved EMD
decomposition method is employed, IMF1 of zero sequence currents of lines are respectively calculated, namely a 1-order
modal function. IMF1 of the lines of one same output wire are compared, the line of which an IMF amplitude absolute value is the largest one, and polarity is opposite to other lines is a fault line. The method is advantaged in that through improving the EMD
algorithm of HHT transformation, computational complexity is reduced, and a fault inspection and sorting speed is further improved.