Research On Eddy Current Thermal Effect Of Non-Contact Power Supply Train

Urban rail transit is the backbone of urban public transport,with the advantages of energy saving,small floor area,large traffic volume,all-weather,less pollution,high safety level,etc.However,the non-contact energy transmission process between train and ground needs to be based on high-frequency electromagnetic field.The car body and most of the structural materials of the train are metal.In the high-frequency electromagnetic environment,the current eddy current will be induced.The eddy current has a thermal effect,and the train may have overheating hazards.Based on the application of noncontact power supply in urban rail transit vehicles--current collection train without network,the influence of train eddy current thermal effect on train system and structure in the process of non-contact power supply from the perspective of eddy current heat is explored in the thesis,so as to provide reference for the application of non-contact power supply in the field of rail transit.The principle of train energy transmission based on contactless power supply system is analyzed in the thesis,and builds the circuit model and field circuit coupling model of contactless power supply system.The output power,efficiency and compensation of the system under different compensation topologies of the contactless power supply circuit are deduced,and the circuit structure is determined.The eddy current effect and the calculation method of eddy current loss power are analyzed to provide theoretical support for the follow-up research.On the basis of principle analysis,the influencing factors of eddy current loss are analyzed quantitatively,and the variation law of eddy current loss in the actual model is summarized.Coupling mechanism is the source of electromagnetic heat.According to the requirements of non-contact power supply system and the limitation of vehicle installation space,the structure and parameters of coupling coil are designed.Through the explanation of heat transfer mode in the process of induction heating,the thermodynamic model of train is built.The rail train based on non-contact power supply system is modeled,and the eddy current field and temperature field of the train body and small metal parts are simulated by ANSYS software.The heating condition of each structure is analyzed,which provides a reference for the research of eddy current thermal safety in the actual train.According to the analysis results,the shielding device is designed to solve the overheating problem in the system.The shielding materials are determined and the magnetic circuit structure of coupling coil is analyzed after adding shielding.Considering the actual operation of the train,the eddy current distribution and temperature rise of the train under different working conditions after adding shielding device are compared and analyzed.The results show that the train system will not overheat after adding shielding device.Finally,the small power experimental platform is built,and the rationality and feasibility of the small power experimental platform are explained through analysis.Taking the metal wafer as an example,the temperature field experiment is carried out.By comparing the simulation and experimental results,it is verified that the simulation in this thesis has practical reference value,which can provide the basis for the research of eddy current thermal effect of non-contact power supply train.