Coil Design and Optimization of Inductive Power Transfer System for Tram

As a new type of urban transit vehicle, Non-catenary trams using inductive power transmission technology get rid of the traditional overhead catenary. In engineering applications, coils assembled on the different tram bodies have inevitable differences due to the restrictions on the production process and other factors. Research shows tiny differences in self-inductance always lead to system detuning so as to causes an extreme descent of the system power factor. From the perspective of hardware design, the paper analyzes the system architecture and coil configuration for the dynamic charging trams with considering cost, system reliability, etc. Then, for the problem of power factor reduction caused by the differences in the self-inductance of the secondary windings, the article establishes a mathematical model with the maximum power factor as the goal and system parameters as constraints. And a complete system parameters design method is proposed. Finally, the global design and optimization of tram's electromagnetic coupling mechanism parameters are performed using the group method. The simulation result indicates that the method can meet the requirements of system operation and has a higher tolerance to the self-inductance differences of the secondary coils

Design of Coupling Coil Parameters for Wireless Charging Tram Based on Electromagnetic Safety

As a new type of urban rail transit tram, wireless charging tram uses high frequency electromagnetic field to conduct inductive power transmission, which gets rid of the traditional overhead catenary network, but inevitably causes electromagnetic radiation to the surrounding environment. Research shows that excessive electromagnetic radiation will affect the normal operation of equipment and the safety of human body. This paper analyzes the structure and coil configuration of the dynamic charging system for wireless charging tram. Aiming at the problem of electromagnetic radiation, a mathematical model with minimum electromagnetic radiation as the target and system parameters as the constraint condition is established. Finally, the system parameters of the electromagnetic coupling mechanism of the wireless charging tram are designed and optimized. The simulation and experimental results show that the method can meet the operating requirements of the system and reduce the electromagnetic radiation to the surrounding environment

Decoupling Control Strategy of IPT System Based on Optimal Efficiency Load Tracking

The inductive power transmission system is applied to urban rail transit. Due to the limitations of the volume and coupling coefficient of the inductive coupling mechanism and the fact that the fluctuation of air gap in its movement will cause the fluctuation of mutual inductance value, DCDC booster link should be added to the side, rectifying side, to improve the output voltage level and stability. At present, most of the existing control strategies are based on the original side information communication. However, in the application of dynamic wireless charging in urban rail transit, the primary and secondary side coils are in the process of relative movement, so it is relatively difficult to establish reliable real-time communication, and it is easy to be interfered by electromagnetic transmission process, resulting in large errors. This paper analyzes the relationship between load and efficiency of IPT system applied to urban rail transit in detail and obtains the optimal load matching strategy of optimal efficiency. At the same time, an independent control strategy is proposed to eliminate the information communication of the primary and secondary sides and realize decoupling control. Finally, a simulation model is built to verify the effectiveness of the control strategy

Preparation of AZO Nanoparticles, Ceramic Targets and Thin Films by a Co-precipitaition Method

We comprehensively study the co-precipitation preparation of aluminum doped zinc oxide (AZO) nanoparticles, ceramic target and thin film deposition. The nanoparticles calcined below 700 degrees C possessed pure wurtzite structure of ZnO. When the calcination temperature exceeded 700 degrees C, ZnAl2O4 phase appeared. The resistivity and relative density of the AZO target pressed from nanoparticles were 3x10(-3) Omega.cm and 99.1%, respectively. The minimum resistivity of AZO thin films prepared by DC sputtering of the ceramic target reached 4.1x10(-4) Omega.cm with the mobility of 33 cm(2)/v.s and the carrier concentration of 4.5x10(20) cm(-3). The average optical transmittance of the AZO thin films in the visible wavelength range (400-800 nm) was more than 80%