Investigation and analysis on electromagnetic impact of UHVDC power transmission lines on telecommunication lines

With the accelerated pace of the construction of UHVDC transmission projects, it is necessary to cope with the electromagnetic compatibility between UHVDC transmission lines and telecommunication lines. The survey and revisit of three UHVDC transmission projects put into operation in recent years, such as ±800 kV DC transmission project from Xiangjiaba to Shanghai and so on, are conducted; and further the distribution of telecommunication lines, the allowable value and its computational method of electromagnetic interference as well as the protective measures for them are analyzed and assessed. Analysis and assessment results show that UHVDC transmission projects impact telecommunication lines greatly and there are lots of telecommunication lines adopt protective measures; it conforms to national conditions of China at the present stage to decide the allowable values of disturbing influences according to the sensitivity coefficients of telecommunication lines. Results of the presented survey and analysis provide the basis for the revision of the industrial standard Technical Code for Designing of the Telecommunication Lines against Danger Effects from Overhead DC Power Transmission Lines.