Quantum mechanics

Constant power circuit

Control (management)

Switched-mode power supply

Voltage

Engineering

Psychoanalysis

Constant current

Power (physics)

Computer science

Current (fluid)

Power factor

Physics

Psychology

Electronic engineering

Artificial intelligence

Maximum power transfer theorem

Wireless power transfer

Control theory (sociology)

Electromagnetic coil

Compensation (psychology)

Electrical engineering

IEEE Transactions on Transportation Electrification

The design of operating frequencies and compensation topologies for load-independent output current or output voltage in two-coil wireless power transfer (WPT) system has been widely studied. The three-coil WPT system has been proven to be more efficient and shows a better performance compared to the two-coil WPT system with an increasing transmission distance. However, the research on load-independent output voltage or output current of the three-coil WPT system is still at pilot stage. This paper systematically investigates the load-independent output voltage and output current characteristics of a three-coil WPT system to achieve a constant output voltage (CV) and constant output current (CC) with near zero reactive power, which can simplify the control. The CV and CC characteristics are achieved by well-designed passive parameters of the receiver side compensation. Additionally, a hybrid receiver side compensation with two additional switches for the three-coil WPT system is developed to charge the electric vehicle battery by combining the CC and CV characteristics. Finally, a scaleddown experimental setup with 4-A charging current and 96-V cell voltage is constructed to verify the proposed approach. The experimental results agree well with the theoretical analysis.

Analysis and Design of Load-Independent Output Current or Output Voltage of a Three-Coil Wireless Power Transfer System