Development of contactless battery power transfer system with coreless PCB planar transformer

• Main Authors: Yang, Chi-Hsiang, 楊智翔
• Other Authors: Chen, Tsair-Rong
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/vyq347

碩士 === 國立彰化師範大學 === 電機工程學系 === 107 === In this study, a contactless power transmission system based on a coreless PCB transformer is developed for the application of the electric scooter’s battery charging. The overall system is mainly divided into two parts: a charging end module and a battery end module. The two windings of the PCB transformer are integrated into the charging and battery modules respectively. The overall size of the modules and the core power losses can be reduced by using the coreless PCB transformer. The LCL resonance compensation topology for the coreless PCB transformer is adopted for the future development of bidirectional power conversion. On the secondary side, the full-bridge diode rectifier is used to convert the high-frequency AC power into a DC power source. After analyzing and simulating the characteristics of the LCL resonance compensation topology, it can be found that the secondary side output current is also almost constant when the primary side voltage is fixed. As a result, a DC converter is integrated into the secondary side to control the battery charging power. In the proposed control strategy, the control signal transmission between the primary and secondary sides is not required, which can reduce the system cost and the controller complexity. A prototype with 100W rated power of the proposed contactless power transmission system is implemented. The input 48V DC power is converted into 12V power for charging the battery. The constant-current/constant-voltage charging method with 14.4V/6.9A is adopted. The efficiency of the developed system is about 71% for the battery charging. From the experimental results, the validity and performance of the proposed system are both verified.