Contactless Power Transfer System Design For Tram

As a new type of urban rail transit vehicle,trams using inductive power transmission technology get rid of the traditional overhead contact network,and have many advantages such as flexible power supply,economical environmental protection and low construction cost.However,the application of contactless power transfer technology to urban rail transit systems is still in its infancy,and there is no systematic design scheme specifically for this application scenario.Therefore,this thesis studies the non-contact power supply technology applied to the network-free tram,aiming to propose a complete electromagnetic coupling mechanism design optimization method and system design scheme in combination with engineering practice,and provide a theoretical reference for the construction of the tram test line.Firstly,the thesis clarifies the technical index and overall structure of the system.After comparing and analyzing the six common electromagnetic coupling mechanism resonance compensation topologies,the SS topology that satisfies the high-power dynamic charging demand of the network-free train is selected.Therefore,the circuit model of the system is determined.Furthermore,the effects of frequency,load and mutual inductance parameters on the output characteristics of the system are analyzed in detail.Then,with the aid of ANSYS Maxwell three-dimensional finite element simulation software,the shape and structure of the electromagnetic coupling mechanism coil are compared and analyzed.According to the actual installation space of the vehicle,a rectangular coil configuration with multiple primary sides and multiple short sides is given.Then combined with the circuit characteristics of the system,a new electromagnetic coupling mechanism parameter design method is proposed.Aiming at optimizing the problem of power factor reduction caused by the difference in self-inductance of the secondary coil,the article establishes a mathematical model with the maximum power factor as the goal and system parameters as constraints,and the coil parameters of the electromagnetic coupling mechanism are optimized.After that,based on the load demand,the paper introduces a control strategy to cancel coils communication and realize the decoupling of the primary and secondary sides.Then the paper builds a 300kW Matlab model of a single module,simulates the self-inductance deviation,mutual inductance and load fluctuation of the secondary coil,and verifies the feasibility of the system design.In addition,the hardware design method and software design of the 1kW low-power experimental platform are introduced in detail.The output characteristics of the system are tested,which provide a reference for the construction of the actual system.Finally,based on the research on electromagnetic radiation related standards,this paper builds a simplified model of electromagnetic coupling mechanism and vehicle 3D electromagnetic simulation,and simulates the electromagnetic environment distribution and safety distance limitation when the system works,which provides a theoretical basis for the establishment of electromagnetic protection measures in the practical application of the system.