A GaN-Based 6.78 MHz Single-Stage Transmitter with Constant Output Current for Wireless Power Transfer

A single-stage transmitter is reviewed which directly converts a utility ac input to high frequency (6.78 MHz) ac output for wireless power transfer applications. Compared with a two-stage transmitter implementation, this single-stage transmitter obtains high power efficiency with reduced component-count. In this paper, a method is proposed to enable constant current at the output of the single-stage transmitter to accommodate multiple receivers. First, the constant output voltage transmitter is obtained by implementing closed-loop control and a model-based modulation scheme. Then, an impedance matching network is implemented at the output of transmitter to convert the constant voltage to constant current. This feature allows a single transmitter to charge multiple receivers simultaneously. The control methodology is verified using both simulation and a laboratory prototype.

[1]  He Yin,et al.  A 6.78 MHz Multiple-Receiver Wireless Power Transfer System With Constant Output Voltage and Optimum Efficiency , 2018, IEEE Transactions on Power Electronics.

[2]  P. Jain,et al.  Asymmetrical pulse width modulated resonant DC/DC converter topologies , 1993, Proceedings of IEEE Power Electronics Specialist Conference - PESC '93.

[3]  J. Acero,et al.  Asymmetrical voltage-cancellation control for full-bridge series resonant inverters , 2004, IEEE Transactions on Power Electronics.

[4]  Songnan Yang,et al.  A GaN-based 100 W two-stage wireless power transmitter with inherent current source output , 2016, 2016 IEEE PELS Workshop on Emerging Technologies: Wireless Power Transfer (WoW).

[5]  Jason Zhang,et al.  Single-stage 6.78 MHz power-amplifier design using high-voltage GaN power ICs for wireless charging applications , 2017, 2017 IEEE Applied Power Electronics Conference and Exposition (APEC).

[6]  Young-Joon Kim,et al.  Selective Wireless Power Transfer for Smart Power Distribution in a Miniature-Sized Multiple-Receiver System , 2016, IEEE Transactions on Industrial Electronics.

[7]  Tong Zhang,et al.  Compensation of Cross Coupling in Multiple-Receiver Wireless Power Transfer Systems , 2016, IEEE Transactions on Industrial Informatics.

[8]  Takehiro Imura,et al.  Cross coupling cancellation for all frequencies in multiple-receiver wireless power transfer systems , 2016, 2016 International Symposium on Antennas and Propagation (ISAP).

[9]  Zhu Han,et al.  Wireless Charging Technologies: Fundamentals, Standards, and Network Applications , 2015, IEEE Communications Surveys & Tutorials.

[10]  Ming Liu,et al.  Autonomous Power Control in a Reconfigurable 6.78-MHz Multiple-Receiver Wireless Charging System , 2018, IEEE Transactions on Industrial Electronics.

[11]  Soo-Won Kim,et al.  Design and implementation of a high-efficiency 6.78 MHz resonant wireless power transfer system with a 5 W fully integrated power receiver , 2017 .

[12]  Chunting Chris Mi,et al.  Wireless Power Transfer for Electric Vehicle Applications , 2015, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[13]  Chengbin Ma,et al.  Battery Cell Equalization via Megahertz Multiple-Receiver Wireless Power Transfer , 2018, IEEE Transactions on Power Electronics.

[14]  Grant A. Covic,et al.  Power Management for Multiple-Pickup IPT Systems in Materials Handling Applications , 2015, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[15]  Ryan Tseng,et al.  Introduction to the alliance for wireless power loosely-coupled wireless power transfer system specification version 1.0 , 2013, 2013 IEEE Wireless Power Transfer (WPT).

[16]  G.A. Covic,et al.  Detection of the Tuned Point of a Fixed-Frequency LCL Resonant Power Supply , 2009, IEEE Transactions on Power Electronics.

[17]  Songnan Yang,et al.  Constant current power amplifier for MHz magnetic resonance wireless power transfer systems , 2017, 2017 IEEE MTT-S International Microwave Symposium (IMS).

[18]  He Yin,et al.  Megahertz Multiple-Receiver Wireless Power Transfer Systems With Power Flow Management and Maximum Efficiency Point Tracking , 2017, IEEE Transactions on Microwave Theory and Techniques.

[19]  Aly Fathy,et al.  A single stage AC/RF converter for wireless power transfer applications , 2017, 2017 IEEE Applied Power Electronics Conference and Exposition (APEC).

[20]  Rui Zhang,et al.  Multiuser Wireless Power Transfer via Magnetic Resonant Coupling: Performance Analysis, Charging Control, and Power Region Characterization , 2015, IEEE Transactions on Signal and Information Processing over Networks.