Study on the Performance of Integrated Grounding Line in High-Speed Railway

The high-speed railway (HSR) has become more important in modern society. However, the rail potential rises remarkably, because of the high leakage resistance to earth with the use of ballastless track and huge traction return current on rail. That is a serious threat to passengers´ and equipment safety along the railway. Integrated grounding line (IGL) can decrease rail potential obviously. Its structure is quite different from grounding rods in non-HSR substations. Meanwhile, IGL goes along the entire railway, and its parameters´ optimization can obtain enormous economic benefits and significantly decrease the workload of laying the line. Therefore, the performance of IGL should be studied in detail. With assessment of grounding impedance and shunting coefficient, the relationships between IGL parameters and its performance have been analyzed. Related experiments had also been carried out on the SUI-YU railway (the first ballastless HSR in China). Compared with the theoretical results, the differences were less than 15% and 5% for grounding impedance and shunting coefficient, respectively. With the analyzing results, some pieces of advice have been proposed.