Centering on the fault analysis and fault line selection scheme for the double HVDC transmission lines on same tower

based on the electrostatic coupling theory

according to the detailed parameters of lines and tower

considering the effects of overhead ground wire and the filter capacitors

a calculation method of the potential coefficient matrix is presented for the double HVDC transmission lines. Then the interline electrostatic unbalanced coupling effect is transformed into mode voltage variation by the phase-mode transformation. Based on the mode voltage variation

considering the different characteristics of ground-mode and line-mode quantum

by the definition of mode voltage variation ratio

this paper proposes a fault feature quantitative analysis scheme of double HVDC transmission lines on same tower to eliminate the influence of transition resistance. Based on the fault case of each mode voltage variation characteristics

a fault line selection method of the double HVDC transmission lines on same tower is proposed. Finally

the PSCAD/EMTDC is used to construct the double HVDC transmission lines on same tower to verify the correctness of the proposed method through all-round fault simulations. The results show that the proposed method is capable of accurately selecting a variety of complicated fault types unaffected by the fault transition resistance. This work is supported by National Natural Science Foundation of China(No. 51307065

No. 51577072)

and Fundamental Research Funds for the Central Universities(No. 2013ZZ028).