面向微型旋转应用的高功率密度电容耦合器

To realize a high-power density capacitive coupler for miniaturized rotary application,a parameter design method is proposed in this article.Since a capacitive coupler is composed of metal plates and external capacitors,limitations include two parts.One is air breakdown voltage limitation of metal plates,and the other one is withstanding voltage limitation of external capacitors.To quantify voltage limitation,voltage stress is analyzed.Then,an optimal design method for external capacitors is proposed,realizing minimum voltage stress and optimal load condition,simultaneously.Using an optimal external capacitor,a parameter design method is proposed to maximize power density.In which,the air breakdown voltage limitation determines the range of resonant frequency.Then,the withstand-ing voltage limitation determines specific resonant frequency and composition of external capacitors.Experimental results show the proposed method can realize DC-DC efficiency of 91.35％and power density of 423 W/in3under a 1 kW output condition.