基于E类逆变电路的宽负载范围软开关无线充电补偿网络研究

Research on Wide Load Range Soft Switching Wireless Charging Compensation Network Based on Class E inverter Circuit

ClassE电路具有结构简单、无直通问题、可靠性高等优点。但是由于传统Class E电路软开关范围窄,传输功率有限,不适合电池充电这种变负载场合。为了解决这些问题,文中提出3种带电容切换补偿网络的新型Class E电路,不仅提高了软开关范围和输出功率,而且只需要切换一次开关即可实现恒流和恒压输出,不需要改变频率或补偿方式。对3种补偿网络考虑软开关裕量进行精确建模,并在阻抗压缩、高次谐波抑制、器件参数、电容应力等方面进行比较和分析,得出S/CL网络具有较大优势。最后搭建实验平台,对S/CL和S/CLC两种网络进行比较,验证S/CL网络具有更好的恒流恒压特性。

Class E circuit has the advantages of simple structure,no shoot-through problem and high reliability.However,due to the narrow soft-switching range and limited output power of the traditional Class E circuit,it is not suitable for the variable load occasions such as battery charging.To relieve this issue,three novel Class E circuits with capacitor switching branch were proposed,which not only improved the soft-switching range and output power,but also achieved constant current and constant voltage output only by switching the branch once without changing the frequency or compensation mode.Considering the soft switching margin,the three compensation networks were accurately modeled,compared and analyzed in terms of impedance compression,high-order harmonic suppression,device parameters,capacitor stress and etc.It is concluded that the S/CL network has greater advantages.Finally,an experimental platform was built to compare S/CL and S/CLC networks,which verified that S/CL network has better constant current and constant voltage characteristics.