Abstract：In order to realize the nonintrusive identification of variable power load, a calculation scheme of identification feature based on the load current waveform was proposed. On the basis of the current waveform of variable power load, the structural characteristics of the waveform including the periodic and odd symmetry were analyzed. By means of the discrete Fourier transformation ( DFT) , the equations of the zero-current region were established. In case of the unlosefulness of the correnctness of the suggested scheme, the reduced equations were made availabe to reduce the computaitonal complexity by ignoring the current harmonics whose modulo was reasonalbe small. And then, the equations were transfered into the compact matrix form. Gaussian elimination tools were employed to turn the matrix into an elegant row echelon. Thus the functional relationship between the fundamental current and the higher harmonics was obtained. The simulation results proved the effectiveness of the proposed algorithm.

Keyword：variable power load;nonintrusive identification;fundamental current;discrete Fourier transformation;