A novel equilvalent model to analyze the influence between the parallel UHVDC and EHVAC transmission lines

A novel equivalent model to analyze the influence between the parallel UHVDC and EHVAC transmission lines is presented in the paper. In the model, the distributed capacitance between the transmission lines and the grounding lines is calculated firstly, then the equivalent circuit can be obtained. The induced voltage on the DC transmission lines caused by the AC transmission lines is calculated. The accuracy of the model in the paper is confirmed by comparing the result and result obtained in this paper. Calculation for the induced voltage on the DC transmission lines for different arrangement of the AC conductors and different distance between the AC and DC transmission lines were carried out, results indicate that the compact AC transmission lines can decrease the induced voltage on the DC transmission line, for which the inducted voltage decreases from 23.9kV to 17.3kV when the distance between the AC transmission lines and DC transmission lines is 40m. When the distance between the AC and DC transmission lines is beyond 140m, the induced voltage is near to zero.