The invention relates to an extra-high-
voltage direct-current
transmission line fault location method based on a
wavelet transformation
transient state energy spectrum, and belongs to the technical field of power
system relay protection. When a direct-current line breaks down, according to two-pole direct-
current voltage collected at a protection installation position (
img file='dest_path_dest_path_image001. TIF'wi= '40' he='24' / ) and (
img file='dest_path_dest_path_image002. TIF'wi= '40' he='24' / ), line mode
voltage (
img file='dest_path_dest_path_image003. TIF'wi= '48' he='24' / ) is obtained,
wavelet decomposition is carried out on line mode
voltage (img file='dest_path_855728dest_path_image003. TIF'wi= '48' he='24' / ) to obtain a high-frequency coefficient of the wavlet
decomposition, the high-frequency
signal wavelet energy sum (img file='dest_path_dest_path_image004. TIF'wi= '21' he='25' / ) is solved by means of the high-frequency coefficient, normalization
processing is carried out on (img file='dest_path_594008dest_path_image004. TIF'wi= '21' he='24' / ) to obtain an input sample of a neural network, and the input sample in the neural network is trained to obtain a fault location result. By means of characteristics of a wavelet energy
frequency band whose appearance is obvious and whose position is easy to determine, a fault position is looked for, and precision of fault location is improved; by means of non-
linear fitting capacity of the neural network, extra-high-voltage direct-current grounded
transmission line fault locating is carried out, the property of the sample is clear, the scale of a sample set is small, convergence efficiency is high, and the method is not prone to being influenced by
system parameter conversion and transition resistance.