KOU Zhiwei, LIU Yanchen, MA Yunwen, et al. Study of constant-current/constant-voltage output wireless power transfer system based on variable capacitance control[J]. 2026, 30(5): 175-188.
KOU Zhiwei, LIU Yanchen, MA Yunwen, et al. Study of constant-current/constant-voltage output wireless power transfer system based on variable capacitance control[J]. 2026, 30(5): 175-188.DOI: 10.15938/j.emc.2026.05.015.
Magnetic coupling wireless power transfer(MC-WPT)technology realizes contactless electrical energy transmission through strong near-field magnetic coupling
opening new avenues for dynamic charging and power supply in complex environments. To address the practical requirements of load decoupling between output voltage/current and load variations
as well as automatic constant current and constant voltage mode switching in MC-WPT systems
an automatic constant current constant voltage switching method based on variable capacitance was proposed. Firstly
by introducing resonanc
e factors
m
and
n
a bilateral LCC resonant network based on variable capacitors was designed
and theoretical feasibility of achieving constant current/constant voltage outputs was analyzed
demonstrating the theoretical capability of continuously tuning the equivalent capacitance on the receiving side of the bilateral LCC network. Secondly
methods for selecting and optimizing parameters of the bilateral LCC resonant network were investigated; the variation characteristics and permissible range of the resonance factor were analyzed; a PID-based control scheme for equivalent capacitance regulation was designed; and an automatic switching control method between constant-current and constant-voltage output modes was established. Finally
simulations and experimental validations confirm the correctness of parameter design
constant current/constant voltage output characteristics
and automatic switching performance. Experimental results demonstrate the system's capability to achieve a constant current output of 3 A and a constant voltage output of 15 V under varying load conditions with constant input voltage
along with seamless automatic constant current/constant voltage switching. Dynamic response fluctuations are limited to 6.67% and 5.33%
respectively
and the maximum transmission efficiency reaches 85.17%
providing a novel technical solution for enhanced intelligence and adaptability in wireless charging systems.