基于E类放大器的经皮能量传输系统的元件损耗分析

摘要

High efficiency is required in a transcutaneous energy transmission system (TETS) to reduce the possibility of tissue damage caused by overheating and increase the portability. This paper presents an analysis of conduction power loss for the TETS driven by class-E amplifier. According to the ideal class-E design equations,the parameter and power loss of each component are expressed as functions of duty cycle. The power loss of each component varies inversely with the square of the supply voltage, directly with the output power, and increases with an increasing duty cycle. When the duty cycle is lower than 0. 5, the efficiency can be greatly improved by increasing the duty cycle; while be little improved when duty ratio is larger than 0. 8. It is revealed that the optimal duty ratio of the TETS driven by class-E amplifier is 0. 5 ～0. 8. Three identical TETS experiments at the duty cycle of 0. 25, 0. 5 and 0. 75 are designed, constructed, and tested. The experimental results match closely with the calculated ones at the power loss and total efficiency when the duty cycle is larger than 0. 3.%经皮能量传输系统(TETS)要求很高的能量传输效率,以减少因元件发热而烧热人体组织的可能性和提高系统的便携性.本研究提出一种基于E类放大器的TETS各个元件传导损耗的分析方法.根据理想E类放大器的参数设计方程,各个元件的参数和损耗表示为E类放大器驱动占空比的函数关系式.通过损耗分析得出各个元件的损耗与输入电压的平方成反比,与输出功率成正比,随着占空比的增加而减小.当占空比小于0.5时,通过增大占空比可以明显提高效率,而当占空比大于0.8时,增大占空比几乎不能再提高系统效率,因此,基于E类放大器TETS的占空比设置在0.5至0.8之间较为合适.理论分析的结果通过占空比分别为0.25、0.5和0.75的实验得以验证.实验表明,当占空比大于0.3时,理论效率值与实验值的误差很小.