Current-Division-Aware Modeling and Detuning Design of a Receiver-Side LCC-Type Three-Coil Wireless Power Transfer System for Fixed-Frequency CC/CV Charging

To satisfy the constant-current/constant-voltage (CC/CV) charging requirements of electric-vehicle batteries, this paper investigates the extension of an established fixed-frequency reconfigurable three-coil wireless power transfer system using a modified receiver-side LCC-type network. The receiver-side shunt capacitor introduces a current-dividing path, so the receiver-coil current differs from the equivalent rectifier-load current and the strict self-resonant value of the L2—C2 branch no longer provides the intended CC regulation. A current-division-aware fundamental-harmonic model is established, and a closed-form correction gives C2 = 21.950 nF instead of the strict resonant value of 22.825 nF at 85 kHz. Calculated results show that the maximum CC target error over RL = 15–35 Ω is reduced from 8.948% to 0.031%, while the calculated CC/CV transition resistance is restored from 39.25 Ω to 34.97 Ω. Comparative analytical results are provided for the series-compensated baseline, the strictly resonant LCC-type configuration, and the corrected LCC-type configuration, together with receiver-current and coupling-sensitivity assessments. At RL = 35 Ω, the retained prototype measurements give an output voltage of 109.14 V, an output current of 3.121 A, an output power of 0.341 kW, and a DC-DC efficiency of 93.120%. The prototype measurements confirm the nominal operating target of the corrected design, while the analytical and numerical results clarify the modeling, correction, and current-stress tradeoffs introduced by the modified receiver network.