无线电能传输系统三相相移控制逆变器研发

Development of a Three-Phase Inverter with Phase-Shifted Control for Wireless Power Transfer System

设计一种为无线电能传输系统提供高频交流电的三相相移控制逆变器。该逆变器由三相D类半桥逆变桥组成,其开关管运行于固定的切换频率下,通过调整各相半桥的驱动相位差来调节输出电压,从而实现无线电能传输系统功率的调节。对三相相移逆变器的主要性能,包括相移角与输出电压的关系、相电流、各相零电压切换状态等进行分析,并推导无线电能传输系统在使用相移控制和频率控制下的效率。开发三相的相移逆变器原型机并应用于无线电能传输系统,在两个外边长为90cm、70cm的平面矩形螺旋线圈间传输能量。实验表明当相移角从0°到120°之间调节时,在接收端10Ω电阻负载上接收到的功率从5.2kW到0变化。同时在最大输出功率时测得逆变器直流输入到接收端直流负载的DC-DC最大效率为94%。

A three-phase inverter with phase-shifted control for wireless power transfer system is developed in this paper.The inverter consists of three Class-D half inverters,whose MOSFETs operate at a constant switching frequency,and its output voltage is regulated via adjusting the driver angle among phases.Accordingly,the power regulation of wireless power transfer can be achieved.Main features of the inverter are analyzed,including the relationship between the output voltage and the phase-shift angle,the phase-currents,and ZVS conditions of each phase.Efficiencies under either phase-shift control and frequency-control are derived.An experimental prototype of phase-shift controlled inverter with3phases is developed and employed in a wireless power transfer system to deliver power between two planar rectangular solenoid coils with out-dimensions of90cm×70cm.Experiments show that when the phase-shift angle is changed from0to120degree,the receiving power at the load of10Ωat the secondary side varies between5.2kW and0kW.Meanwhile,when the system operates at the maximum output power,the DC-DC maximum efficiency is94%,which is defined as the ratio of the DC-load power at the receiving side to the inverter DC-input power at the sending side.