High-Frequency Characteristics for Wireless Charging Systems for EV

Wireless Power Transfer (WPT) has emerged as a highly promising solution for Electric Vehicle (EV) charging applications. This paper presents the work to evaluate the output characteristic and the transmission efficiency of the EV-WPT (Wireless Power Transfer for EV) system. Increasing the operating frequency in EV-WPT effectively reduces the size of the coupler, reducing the cost. However, higher working frequencies bring new challenges, such as increased switching losses. Using an SS-compensated WPT topology as an example, this study analyzes the system transmission efficiency, energy losses with different operating frequencies. Moreover, synchronous rectification technology is applied to the rectifier, which accounts for the highest efficiency loss in the system, reducing its power loss to as low as 4%. Experimental results show that after efficiency optimization, the system maximum transmission efficiency is 86.88%.