normalization of data..

Hi..I am doing my project on fault classication of transmission lines using a AI technique. In my base paper, three phase voltages and six current input signals were sampled at a sampling frequency of 1 kHz and further processed by simple 2nd-order low-pass Butterworth filter with cut-off frequency of 400 Hz. Subsequently, one full cycle Discrete Fourier transform is used to calculate the fundamental components of voltage and current. The inputsignals were normalized in order to reach the ANN input level...

now my doubt is..what is the requirement or necessity fundamental components of voltage and current which were never used anywhere ..are those values some how related to the normalization..please help