为实现电动磁浮列车低速运行阶段无接触辅助供电,同时尽可能减轻耦合机构重量,并保障供电系统平稳输出,该文设计了一种利用磁浮系统原有线圈作为耦合机构的感应式电能传输(IPT)系统,通过线圈与电路结构重构,以列车低速运行阶段空置的悬浮线圈与集电线圈作为能量传输通道.由于不需额外安装能量传输线圈,所提出的IPT系统对磁浮列车自重影响小,且耦合机构在移动过程中具有互感恒定的特性,结合LCC-S谐振补偿电路,IPT系统在列车移动过程中与负载变化过程中均能保持稳压输出.为验证所提方案的可行性和有效性,搭建了 1 kW 的原理样机,在移动供电过程中,IPT系统输出电压波动仅 1.51%,输出功率在 300~1 000 W范围变化时,输出电压波动为 4.42%,系统整体效率为 83.75%~86.61%.
The power supply capacity of the linear generator is insufficient when the electrodynamic suspension(EDS)maglev train is at low speed or stationary.The contact power supply device is used as an additional power supply,resulting in wear,noise,and poor weather resistance,which affect running safety and ride comfort.In recent years,the development of inductive power transfer(IPT)technology has been relatively mature.It uses high-frequency magnetic fields as the medium to realize energy transmission between coupling coils,which has outstanding advantages such as contactless and flexible charging.However,to promote this technology in the maglev train,the IPT system has to be lighter and more compact.Therefore,this paper puts forward a reuse method of coil and circuit to build the integrated IPT system.By changing the coil and circuit structure,the suspension and collector coils,vacant when the train is at low speed,are used as the energy transmission channel.The proposed IPT system has little influence on the dead weight of the maglev train,and the mutual inductance of the coupler can be constant during the moving process.Combined with the LCC-S resonant compensation circuit,the stable output voltage is realized in the train movement and load change process. First,according to the characteristics of the multi-coil coupling of the electrodynamic suspension maglev train and different coil modes under different speeds,an integrated IPT system based on reconfigurable coils and circuits is proposed.The working modes of coils and circuits at different train speeds are analyzed in detail,and the structure and reconstruction strategy of coils and circuits are designed for contactless power transfer without affecting the original function of the train or increasing the weight of the train. Then,an equivalent circuit model of the coupler is established to clarify the mutual inductance fluctuation of the coupler during the moving process of the train.The Fourier series is used to characterize the relationship between the mutual inductance of the coils and the displacement,which simplifies the mutual inductance fluctuation analysis of the multi-input multi-output coupler.The results show that the multi-input and multi-output coupler constructed by reusing suspension coils and collector coils has the characteristics of constant mutual inductance during the moving process of the train. Moreover,to ensure the stable voltage output of the IPT system under different loads,an LCC-S resonant compensation circuit with a centralized compensation capacitor on the secondary side is proposed.Based on the mathematical model of the circuit topology,the compensation topology parameters for realizing the constant voltage output of the system are derived. Finally,based on the system coil structure and circuit topology,combined with the established mathematical model,a scaled experimental platform for the integrated IPT system of the EDS maglev train is designed and built.Through the experiment,the constant mutual inductance characteristics of the coupler and the constant voltage output characteristics of the system when the load changes are verified.In the moving process,the output voltage fluctuation is only 1.51%.When the output power varies from 300 W to 1 000 W,the output voltage fluctuation is 4.42%,the overall efficiency of the system is at least 83.75%,and the highest is 86.61%.