Electromagnetic Environment Analysis Of Rail Transit Vehicles And Platform Based On Wireless Charging

Rail transit vehicles based on wireless charging technology have many advantages such as flexible power supply and safety.However,in the process of energy transmission,wireless charging technology will inevitably have an impact on the surrounding environment and organisms.In addition,the internal coupling of the wireless charging system and its coupling with the external environment,body,chassis and other components also have potential risks of electromagnetic radiation leakage.Therefore,taking the rail transit vehicle based on the wireless charging technology as the application background,the coupling mechanism and the electromagnetic safety of the rail transit vehicle system are studied in this paper.It provides a theoretical reference for practical safety of rail transit vehicles based on wireless charging technology.Firstly,the basic composition and working principle of rail transit vehicles based on wireless charging technology are analyzed.Based on the system's technical indicators and overall structure,the system's circuit model,coupling coil model,and system field-circuit coupling model are established.The system's output power,efficiency parameters and the calculation formula of the coupling coil's magnetic field strength are derived to analyze the system.The calculation principle of the magnetic field strength of the system is analyzed,which provides theoretical support for the electromagnetic security analysis of the system.Coupling coil is the source of potential electromagnetic safety hazards.The design of parameters of coupling coil based on electromagnetic safety can fundamentally reduce the potential electromagnetic safety hazards of the system.Firstly,ANSYS and Maxwell simulation software is used to analyze the magnetic field distribution characteristics of rectangular coupling coil.Secondly,the relevant electromagnetic radiation standards are analyzed,and the standards formulated by the International Commission on Non-Ionizing Radiation Protection(ICNIRP)in 2010 are selected as the electromagnetic standards analyzed in this paper.Then,the configuration and size of the coupling coil are determined based on the vehicle installation space to reduce the external electromagnetic radiation of the coupling coil.Finally,a mathematical model with the minimum electromagnetic radiation as the target and the output power,efficiency and compensation capacitance voltage as the constraint conditions is established todesign the coupling coil parameters.On the basis of coupling coil electromagnetic safety design,the electromagnetic safety of rail transit vehicles in operation is analyzed,and the parts that do not meet the electromagnetic safety are designed to ensure the electromagnetic safety of rail transit vehicles in operation.The model of rail transit vehicle system based on wireless charging technology is built.The magnetic field strength inside and outside the vehicle and the eddy current loss of the system are analyzed.According to the analysis results,the platform shielding device is designed from the material,thickness,and shape.A mathematical model with minimum cost as the goal,magnetic field intensity standard and actual space size as the constraint conditions is established to optimize the shielding device parameters.Finally,the coupling coil design and is verified by MATLAB~?simulation and the platform shielding design is verified by ANSYS Maxwell simulation.The feasibility of small power platform to verify large power system is proved by analysis.The 1k W small power experimental platform is used to verify that the coupling coil parameter design and platform shielding device design proposed in this paper can meet the requirements,which provides a theoretical basis for the practical application of rail transit vehicles based on wireless charging technology.