Electrical engineering

Physics

Compensation (psychology)

Electromagnetic coil

Power factor

Psychoanalysis

Engineering

Voltage

Artificial intelligence

Psychology

Power (physics)

Control (management)

Electronic engineering

Wireless power transfer

Computer science

Constant current

Quantum mechanics

Constant power circuit

Control theory (sociology)

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