Constant transmission line parameters are bound to lead to a greater traveling wave calculation error due to the frequency dependent characteristic of transmission line. So

based on the superposition theorem

a time sequence wave impedance matrix is given in this paper. The matrix describes the non-linear relationship between traveling wave voltage and current in time domain for any waveform. In addition

the double exponential wave is used in fit-ting transient waveform to obtain higher accuracy. On this basis

the proposed method is applied to fault location

and a fault location algorithm for high-voltage direct current(HVDC)transmission lines considering frequency characteristic is proposed. A lot of simulation results based on PSCAD/EMTDC platform are given to demonstrate that the traveling wave calculation method can effectively consider the frequency dependent characteristic of transmission line

has higher accuracy and lays a foundation for engineering application such as further improvement of the calculation of the fault location algorithm etc. This work is supported by National Natural Science Foundation of China(No.51577072)and Fundamental Research Funds for the Central Universities(No. 2013ZZ028).