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.
作者
邵谣夏
张欢
刘明
马澄斌
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)
出处
《电源学报》
CSCD
北大核心
2020年第5期35-42,共8页
Journal of Power Supply
关键词
兆赫兹
无线电能传输
恒压输出
恒流输出
负载牵引
megahertz
wireless power transfer
constant-voltage output
constant-current output
load-pull
