Electromagnetic Characteristics Analysis Of Zero-Sequence Linear Generator For Superconducting Maglev Train

High-speed maglev train is an important development field of Chinese transportation power strategy because of its advantages of fast and convenience,safety and reliability,green energy saving and less maintenance in the later stage.Traditional contact power supply system is no longer applicable when the train runs at high speed due to large wear and tear,low power supply reliability and other factors,so non-contact power supply system is required.Therefore,on-board linear generator has become a key technology and an important research direction for the power supply system of high-speed maglev trains because of its advantages of high efficiency,convenient maintenance,and reliable power supply.The basic linear generator in the preliminary design has a single function and cannot effectively reduce the train vibration.By improving the size and arrangement of the collector coil,zero-sequence linear generator can not only meet the power supply requirements of the train,but also produce damping effect,reduce train vibration and increase ride comfort by injecting zero-sequence current into collector coil.In this paper,the three-dimensional analysis model of the zero-sequence linear generator is established by the finite element method,and the current collecting capacity,the force condition and the damping effect of the zero-sequence linear generator under different working conditions and different attitudes of the train are studied.Firstly,the research background and significance of the subject are expounded,and the development situation and operation principle of high-speed maglev trains at home and abroad are briefly introduced,and then the working principle and research status of linear generators for high-speed maglev trains are summarized.Then,for the two distribution modes of the basic type and zero-sequence collector coils,the three-dimensional analysis model of the linear generator is established by ANSYS finite element software,and the energy transfer relationship and the magnetic field coupling mechanism of the superconducting coil,the suspension coil and the collector coil are analyzed.The damping principle of zero-sequence current in zero-sequence linear generator is studied by analytical method.Finally,according to the constructed three-dimensional finite element model of zero-sequence linear generator,the electromagnetic characteristics of the linear generator under different operating conditions and different attitudes of the train are studied.The main purpose is to clarify the variation characteristics of the induced current and magnetic field of suspension coil,the current collecting ability of collector coil,and the force of bogie when the train is at different speeds,suspension heights,lateral offsets,and pitch and yaw attitudes.The damping effect of zero-sequence current on the train is emphatically analyzed.The simulation results show that the zero-sequence linear generator can effectively increase the train damping while meeting the power supply demand of the train.