Constant Current/Voltage Charging for Primary-Side Controlled Wireless Charging System Without Using Dual-Side Communication

To realize the misalignment insensitivity and stable constant current/voltage (CC/CV) charging without using the extra dc-dc converter, composite compensation topology, and wireless communication modules, a primary-side control method based on the phase-shift full-bridge inverter and the laminated magnetic coupler (LMC) is proposed for the wireless charging system. First, the load-independent output current and voltage characteristics for the series-series compensation are analyzed. The equations for estimating the charging current and voltage are deduced by only using the primary-side parameters. Second, the excellent antimisalignment capability of the LMC with the primary-side integrated auxiliary coil is verified. As a result, the influence of horizontal misalignment on the estimation precision is reduced; the controllability of the charging current is ensured. Third, the dual-loop cascade PI controller is designed, and CC/CV charging is realized by adjusting the phase-shift angle. Finally, both the simulation and experimental results show that the primary-side control method realizes CC/CV charging with high precision within the reasonable horizontal misalignment range. Compared to the conventional primary-side control methods, the proposed one avoids both the load resistance estimation and mutual inductance identification. Meanwhile, the compact and lightweight receiver module is ensured.

Automated summary

The proposed primary-side control method for wireless charging system achieves high precision CC/CV charging, reduces the influence of horizontal misalignment on estimation accuracy, and ensures controllability of charging current.