Study On The Current Flow Of EMU’s Body And Restraining Method

High-speed railway is rapidly developing due to the advantages such as high speed, safety and comfort, large carrying capacity, eco-friendly, etc. The requirements for the running safety of high-speed railway are more stringent, since the train running speed and load increase constantly. In order to further improve the operation quality of high-speed railway, it is urgent to enhance the technical level of the EMU, and optimizing the grounding system is one of the important technical problems. In recent years, a lot of problem caused by unreasonable grouding system in its setup happen frequently, such as logic control system disordered, circuit insulation breakdown, electronic components burned. Therefore, the research work on the grounding system of EMU is of great urgency, which is combined with line condition and the main circuit structure of EMU.The article introduces the grounding system of EMU from different perspectives and analyses the function and working principle of grounding system. On this basis, we conducted field test about the grounding system of a certain EMU and established the simulation model of current flow of EMU’s body. Through the comparison of simulation results with test data, we demonstrated the reliability of the model. Through this model, the following work has been carried out:We analyze the influence law of working earthing place and protective earthing place to current flow of EMU’s body, and compare the strengths and weaknesses of different grounding plans through the distribution of current flow and the potential size of EMU’s body. Major conclusions are as follows:appropriately increasing working earthing place number and change its position can decrease working grounding current and the current differential between different working earthing places; The settings of protective earth place should decrease the circulation path as much as possibly.We analyze the influence law of grounding resistor to current flow of EMU’s body, and from the simulation results we found that grounding resistor mainly inhibit the current flowing to body, so the grounding resistor work better when there are less circulation pathes. Through the distribution of current flow and the potential size of EMU’s body, we analyze the reasonable value range of grounding resistor, and decide which body were more suitable for the set of grounding resistor.The simulation results provides theoretical basis for the improvement of grounding system.