地铁车辆斩波回路与计轴器电磁耦合机理分析及抑制研究OA

To address the practical engineering challenge of false operations by trackside axle counters caused by strong magnetic field interference from chopper circuits in metro vehicles,a systematic study of the electromagnetic coupling mechanism and suppression measures was conducted.An equivalent circuit model simulating mutual inductance coupling between chopper circuits and the axle counters'magnetic heads was established,revealing the physical mechanism of interference transfer.Furthermore,complete mathematical modeling and quantitative derivation were performed for the first time for the suppression mechanisms of two engineering measures—reducing the wiring loop area and using shielded cables.To verify the theoretical results,a combination of finite element electromagnetic field simulation and field measurement methods was employed.Magnetic field suppression effects were quantified through simulations for different wiring options(same-side vs.opposite-side routing,cable spacing,twisting)and for shielding,with shielding reducing the maximum magnetic field intensity at axle counter positions by 25.5 dBμA/m.In an interference case based on a metro line,after the shielded cable modification was implemented,the equivalent interference current of chopper circuits at the axle counter's operating frequency(29.6 kHz)decreased by 20.7 dBμA,and the trackside magnetic field intensity decreased by 22.5 dBμA/m,effectively resolving the interference.This paper offers a complete characterization of the coupling path of chopper circuit interference,from theoretical modeling and mechanistic quantification to engineering validation,and clarifies the effectiveness and quantitative relationship of the two suppression measures.These results establish a direct theoretical basis and validated solutions for designing and modifying electromagnetic compatibility between traction and signaling systems in rail transit.