Wireless Power Transfer (WPT) has been the research focus and applied in many fields. Normally power is transferred wirelessly to charge the battery, which requires specific load characteristics. The load characteristics are essential for the design and operation of the WPT system. This paper investigates the load characteristics of the WPT system with different resonant types and resonator numbers. It is found that in a WPT system with series or LCL resonance under a constant voltage source, the load characteristic is determined by the number of inductors. Even number of inductors results in a constant current characteristic and odd number constant voltage characteristic. Calculations, simulations, and experiments verify the analysis.


Electrical and Computer Engineering

Research Center/Lab(s)

Electromagnetic Compatibility (EMC) Laboratory


National Science Foundation (U.S.)


This work is supported by the Major Program of the National Natural Science Foundation of China (51490683).

Keywords and Phrases

Electric power systems; Energy transfer; Resonators; Constant current; Constant voltage; Design and operations; Load characteristics; Research focus; Specific loads; Wireless power transfer; Wireless power transfer (WPT); Inductive power transmission

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

File Type





© 2017 American Institute of Physics (AIP), All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.

Publication Date

01 May 2017