基于同侧解耦型电场耦合机构的多发射多接收无线电能传输系统

Same-Sided Decoupled Electric-Field Coupler Based Wireless Power Transfer System with Multi-Transmitter and Multi-Receiver

近年来,随着供电水平要求的提高,单发射单接收的电场耦合无线电能传输(EC-WPT)系统难以满足不同功率等级应用的需求。采用多发射多接收的EC-WPT系统可以有效地扩展输出功率等级。然而,在考虑耦合机构的全电容模型的情况下,因为传能通道间的耦合关系,多发射多接收的EC-WPT系统会存在系统失谐问题。为了解决此问题,该文提出一种基于同侧解耦型耦合机构的双发射双接收的EC-WPT系统。首先,建立一个典型的双发射双接收EC-WPT系统模型,分析同侧耦合对系统谐振的影响效果。然后,提出基于分裂极板的解耦型耦合机构的结构,论证其应用在EC-WPT系统电路中的解耦效果并分析了其解耦原理、耦合系数及偏移性能。最后,搭建了一个功率为200 W的实验样机。实验结果表明,所提出的耦合机构具有较好的同侧解耦特性,基于该耦合机构的EC-WPT系统能在不同工作条件下始终保持谐振状态。

In recent years,with the improvement of power supply levels,electric-field coupled wireless power transfer(EC-WPT)systems with a single transmitter and single receiver cannot meet the demands of applications with different power levels.The EC-WPT system with the multi-transmitter and multi-receiver can effectively expand the output power level.For a magnetic-field coupled wireless power transfer(MC-WPT)system with the multi-transmitter and multi-receiver,there is same-sided coupling between the power transmission channels,which will affect the resonance state of the system and then decrease the transmission performance of the system.Similarly,the EC-WPT system with multi-transmitter and multi-receiver also has system detuning problems because of the coupling relationship between the power transmission channels.The MC-WPT system has two decoupling methods:the circuit decoupling method and the magnetic path decoupling method.However,the system detuning problem caused by same-sided coupling in an EC-WPT system with the multi-transmitter and multi-receiver must be addressed and effectively solved.Therefore,this paper proposes a same-sided decoupled electric-field coupler to relieve the influence of the same-sided coupling of the multi-port capacitive coupler on system resonance.First,a typical EC-WPT system with the dual transmitter and dual receiver is established.Considering the full-capacitance model of the electric-field coupler,the equivalent circuit model of the system is built based on Ansys Maxwell finite element simulation and the capacitive coupling interface modeling method with an arbitrary number of ports.Moreover,the effect of the same-sided coupling on the resonance of the system is analyzed.According to the analysis of the system impedance,EC-WPT systems with the traditional dual-transmit and dual-receive coupler cannot always keep resonant operation under a wide range of loads due to the same-side coupling.Then,the structure of the decoupled coupler based on the separate-plate is proposed,and the connecting method of all the separated plates of the coupler is explained in detail.Furthermore,the decoupling effect,decoupling principle,and coupling coefficient of the EC-WPT system with the decoupled dual-transmitter and dual-receiver coupler are demonstrated.The decoupling performance on the condition of x-misalignment and different coupling distances are analyzed.Finally,an experimental prototype with a transmission power of 200 W is built to verify the decoupling effect of the EC-WPT system with the same-sided decoupled dual-transmitter and dual-receiver coupler based on the separate-plate.The same-sided decoupled effect of the proposed electric-field coupler is verified by the comparison experiment of the same-sided decoupled effect test of the EC-WPT system based on the traditional coupler and the separate-plate coupler.In addition,the x-misalignment experiment proves that the proposed coupler still has decoupling characteristics on the condition of the coupler deviated.The EC-WPT system with dual-transmitter and dual-receiver based on decoupled coupler is constructed with 20Ωand 200Ωas DC loads,respectively.The experimental results show that the output voltage and current of two inverters are in phase.Compared with the power transmission experiments of the EC-WPT system based on traditional couplers and same-sided decoupled couplers under various load conditions,the transmission power and efficiency of the proposed system are higher.