Research on a maximum efficiency and constant voltage output control technology for wireless power transfer system

Abstract

Aiming at the problems of constant voltage output and maximum efficiency of wireless power transfer technology, a wireless power transfer technology based on energy injection and phase-shifted constant voltage control methods is proposed. Firstly, the characteristic functions such as system voltage gain and transmission efficiency are obtained through circuit analysis. Based on this, a novel control method is designed. By changing both the energy injection duty cycle and phase shift angle of the inverter, both the maximum efficiency and constant voltage output of the system are realized when the load changes. The experimental results verify the feasibility of the proposed technology and the correctness of the theoretical analysis. The overall efficiency of energy injection and phase-shifted constant voltage control method is 3%~10% higher than that of the common phase-shifted constant voltage control method within the whole load variation range. At full load, the overall efficiency reaches 89%.

Keywords

• wireless power transfer
• energy injection
• constant voltage
• maximum efficiency