Electric-field Coupled Power Transfer System With ?-A Composite Resonant Network And Its Tuning Control

Wireless Power Transfer(WPT) has made a series of achievements in the theoretical research and engineering technology, and it has been applied in many fields, such as electric cars, mobile robots and intelligent manufacture. As a method of wireless power transfer, Electrical-field coupled Power transfer(ECPT), which uses electric field as its electricity transmission medium, has received a high degree of attention by domestic and foreign experts and scholars with its typical advantage. They have made great efforts on the research of the issues such as the construction of electrical energy transformation topology, the design of coupling mechanism, constant current control of the primary side, etc, and also have obtained many worthy theoretical achievements. Also ECPT has been applied in many fields, such as aerospace motor, electric cars, biomedical electronics, lighting appliance, tablet PCs charge and so on.This paper firstly explained the domestic and overseas research status of ECPT system and briefly introduced the work principle and typical advantage of ECPT system. Secondly, the current electrical energy transformation topologies of ECPT system have been analyzed in detail. In the basis of it, to solve the conflict between high-voltage excitation need of the coupling structure and the low-voltage need of switches MOSFET in the high-frequency power-conversion link, this paper proposed a new topological structure for ECPT system with ?-S composite resonant network, which consists a ?-CLC resonant circuit on the primary side and a S-type resonant circuit on the secondary side. Based on the analysis of the frequency characteristic, power transmission characteristic and voltage transfer characteristic of the ?-S type ECPT system model, this paper presented the parameter configuration method to make it work with ability to boost the voltage between primary plates and also analyzed parameter sensitivity of the ECPT system.Aiming at the decrease of ECPT system transmission performance caused by the variation of transmission distance, this paper proposed a stepless tuning method based on phased-inductor, which made the system work at resonant state when the transmission distance varies in the range of 1 mm to 5 mm, and it also increased the transmission power and the system stability. Then in this paper,the simple tuning control circuit and software of the novel ECPT system has been designed.Finally a simulation model was built based on the Matlab/simulink platform, and the experiment setup was also built. Simulation and experimental results verified the effectiveness and validity of the proposed topology and tuning method.