基于全局负载牵引的兆赫兹恒压输出无线电能传输系统优化设计方法  

Optimal Design Method for Megahertz Constant-voltage Output Wireless Power Transfer System Based on Global Load-pull

作　　者：邵谣夏 张欢[1] 刘明 马澄斌[1] SHAO Yaoxia;ZHANG Huan;LIU Ming;MA Chengbin(University of Michigan-Shanghai Jiao Tong University Joint Institute,Shanghai Jiao Tong University,Shanghai 200240,China;Department of Electrical Engineering,Princeton University,Princeton 07450,USA)

机构地区：[1]上海交通大学密西根学院,上海200240 [2]普林斯顿大学电气工程系,普林斯顿07450

出　　处：《电源学报》2020年第5期35-42,共8页Journal of Power Supply

摘　　要：近年来无线电能传输技术在消费电子领域得到广泛应用,而接收端的恒压/恒流输出特性可以显著简化负载功率的控制。兆赫兹(MHz)无线电能传输系统由于其各环节复杂的阻抗特性,使得千赫兹(kHz)系统中常用的恒压/恒流拓扑设计难以达到其应有效果。首先,详细分析了E类兆赫兹无线电能传输系统的各部分特性,提出一种基于全局负载牵引的系统优化设计方法。该方法在结构上仅需在发射端增加一枚电容即可实现接收端的恒压/恒流输出,同时使得系统效率在负载变化时稳定在较高水平。最后,搭建了工作频率为6.78 MHz的20 W、10 V恒压输出无线电能传输系统样机,并与传统单点负载优化设计的系统进行比较。该系统在5~20Ω的负载变化范围内电压浮动范围在1 V以内,效率保持在76%~84%,实验结果证明了所提方案的有效性。In recent years,wireless power transfer(WPT)technology has been widely applied in consumer electronics,and the constant-voltage(CV)/constant-current(CC)output characteristics of the receiver can promote the simplification of load power control obviously.Megahertz(MHz)WPT systems are more complicated in impedance characteristics,making it difficult to effectively implement the CV/CC topologies which are commonly used in the kilohertz(kHz)systems.First,the characteristics of each part in a class-E MHz WPT system are systematically analyzed in this paper,and a system optimal design method based on global load-pull is proposed.This method only needs to add a capacitor to the transmitter to achieve CV/CC output at the receiver.Meanwhile,the system efficiency is stabilized at a higher level under load changes.Finally,a prototype of WPT system working at 6.78 MHz with a CV output of 10 V and 20 W was built,and it was compared with a system which was optimized by the traditional single-point load design.The voltage fluctuation of this system was within 1 V under load changes of 5~20Ω,and its efficiency was maintained at 76%~84%,demonstrating the effectiveness of the proposed scheme.

关 键 词：兆赫兹 无线电能传输 恒压输出 恒流输出 负载牵引 

分 类 号：TM724[电气工程—电力系统及自动化]