In order to quantify the harmonic contributions on the point of common coupling(PCC)

a new method based on waveform matching is proposed. Firstly

a model of linear regression equation between harmonic voltage amplitude and harmonic current amplitude is established

which avoids the direct measurement of harmonic phase. In consideration of the error to the equation brought by the fluctuation of the background harmonic

the dynamic time warping(DTW)distance is used to analyze the harmonic data to select the sub sequences of high similarity. The utility equivalent harmonic impedance is estimated by the least square method

and then the customer harmonic contributions are calculated. The results of simulation and field measurement analysis show that the method has high accuracy and can restrain the influence of the fluctuating harmonic in the background. This work is supported by National Natural Science Foundation of China(No. 51477029).