Research On Urban Rail Transit Catenary Lightning Protection

Urban rail transit outdoor segment catenary,vulnerable to the impact of the lightning over-voltage.Also appeared in the operation of an accident caused by lightning the rectifier trip and locomotives outage,a great impact on people’s travel convenience.It is necessary to study to analyze the mine problem and propose targeted measures to improve the reliability of the rail transportation.This paper first introduces the catenary power supply and mines the status quo,the status quo under catenary lightning Withstand Level and lightning Withstand Level catenary lightning directly stroke obtained from the theoretically calculated catenary lightning withstand lower level.Lightning insulators,combined with catenary lightning withstand level found likely to cause lightning the catenary insulator flashover or damaged causing line trip.The field is located in the elevated section of the catenary relative height higher probability affected by the lightning directly stroke.And on analysis catenary power supply line to the incoming wave is often caused by the invasion of the rectifier substation voltage is too high.Then analyzes the catenary terminal ground pressure is bad easily lead to local ground grid voltage rises.Finally,from the theoretical analysis of lightning over-voltage Catenary tower below the elevated section of the cable,come lightening zoom in the 40kA may damage the cable insulation or cause damage to the equipment connected to the secondary cable.In response to these problems,solve the problem of catenary lightning easy trip on the proposed installation catenary protection gap,and from laboratory tests and ATP/EMTP simulation analysis of the feasibility of installation catenary protection gap from theoretical and laboratory tests installation distance protection gap Catenary induced overvoltage protection gap protection distance of about 30m,it is recommended that each base tower must be installed catenary protection gap,follow-flow problems for the catenary protection gap flashover laboratory test analysis,the protection gap flashover is not easy wheeling.Lightning directly stroke suffered elevated section,combined with the protection gap flow capacity from the theoretically calculated the height of the elevated section of the erection of the lightning conductor.Catenary terminal grounded grounding device is designed and analyzed by ANSYS and equalizing effect of the diffuser effect of the grounding device,obtained local ground potential rise the original grounding device relative to a 28%reduction,diffuser also have a larger decrease in radius with respect to the original grounding means.Cable lightning protection,and join in the cable near the ground or shielding to reduce lightning on the bottom of the tower or the viaduct section of the cable,and the two protective effect by ATP/EMTP simulation analysis,simulation results show that these two methods effects are influenced by the ground,especially shielding protection affected by the ground more obvious,pay attention to the validity and reliability of the ground in the transformation.