A Traction Network Chain-Circuit Model With Detailed Consideration of Integrated Grounding System in Tunnel Path

The integrated grounding system in the tunnel path of the high-speed railway (HSR) is generally ignored or equivalent to an approximate impedance in the existing traction network chain-circuit models. To enhance the completeness and accuracy of the model, the impedance frequency characteristics of the tunnel grounding electrode is considered in detail and an improved traction network chain-circuit model is presented. By taking a direct traction power supply system as an example, the complicated structure of grounding electrode is included in the established model of tunnel integrated grounding system using the software package of current distribution, electromagnetic, grounding, and soil structure analysis (CDEGS). The impedance frequency characteristics are extracted via CDEGS software simulation. On this basis, particle swarm algorithm is employed to obtain an equivalent circuit of a grounding electrode. Finally, by integrating the grounding electrode equivalent circuit into the chain-circuit model, the improved modeling scheme is elaborated. The real-life experimental data of Chinese HSR line from Wuhan to Jiujiang is used to verify the effectiveness of using a broadband-circuit model to represent tunnel grounding electrode. The real-life experimental data of Chinese HSR line from Xi'an to Chengdu is given to confirm that the presented chain-circuit model is more accurate than the existing chain-circuit model.