多线圈无线电能传输系统效率最大化研究

Maximized Efficiency of Multi-coil Inductive Power Transfer System

感应式无线电能传输系统主要依靠耦合线圈将能量从电源端传输到负载端。多线圈的耦合特性可以用来构建多输入多输出的无线能量传输网络,目前针对此类网络的稳态特性分析仍然不具有通用性。传输效率作为系统稳态特性之一,是多线圈系统的重要优化目标。由于线圈寄生电阻使得耦合器损耗占据整体系统损耗的大部分,因此,优化系统效率的关键在于最大化耦合线圈效率。首先,建立任意耦合线圈个数的无线充电系统的电路模型,依照输入输出稳态特性分析效率最大化的影响因素以及最优效率点下的功率分配和损耗;其次,仿真验证不同输入端和不同输出端时理论分析的准确性;最后,搭建实验平台验证多发射多接收无线充电系统效率最大化点的稳态特性。

In inductive power transfer(IPT)systems,the coupling coils are used to transfer power from the DC source to load.The coupling characteristics of multiple coils can be used to form a multi-input multi-output wireless power transfer network.However,there is no general analytical method for the steady-state characteristics of this type of network.As one of the system’s steady-state characteristics,transmission efficiency is also an important optimization objective for the multi-coil system.Since the loss of coupling coils occupies most of the overall system loss due to the parasitic resistance of coils,the key to the optimization of system efficiency is the maximized efficiency of coupling coils.First,the circuit model of an IPT system with arbitrary coupling coils is built,and the influencing factors for maximized efficiency as well as the power distribution and loss at the operating point with maximum efficiency are analyzed according to the steady-state input-output characteristics.Then,the theoretical analysis in the cases of different inputs and different outputs is verified by simulations.Finally,the steady-state characteristics of a multi-transmitter multi-receiver IPT system at the operating point with maximum efficiency were verified based on an experimental setup.