A Magnetic Integrated Method Suppressing Power Fluctuation for EV Dynamic Wireless Charging System

This article proposes a magnetic integrated method for the coupler of the electric vehicle dynamic wireless charging system to suppress power fluctuation by transforming the problem into designing a stable equivalent mutual inductance between the receiving coil and transmitting coils on the road. Both primary-side and secondary-side couplers adopt a magnetic integrated design. The primary-side coupler integrates a reverse coil inside the transmitting coil, and the secondary-side coupler integrates a coil in the LCC resonance compensation inside the receiving coil. Two advantages are unveiled through theoretical analysis of system characteristics: the original single mutual inductance is replaced by the mutual inductance difference between the two reverse series transmitting coils and the receiving coil to determine the power transmission, which suppresses output power fluctuation; the secondary-side integrated inductor coil replaces the external bulky compensation inductor in the LCC resonance compensation network and additionally realizes better zero-voltage switching conditions. The optimized design process considering the additional couplings is given based on circuit analysis. A prototype is implemented to validate the proposed design. Experimental results show that the output power fluctuation is within +/- 4% during dynamic charging at a power level of 4.5 kW, and the efficiency reaches 91.6%.

Automated summary

This article proposes a magnetic integrated method for the coupler of the electric vehicle dynamic wireless charging system to suppress power fluctuation. The method replaces the original single mutual inductance with the mutual inductance difference between the two reverse series transmitting coils and the receiving coil to determine the power transmission, which suppresses output power fluctuation. Additionally, the secondary-side integrated inductor coil replaces the bulky external compensation inductor in the LCC resonance compensation network and achieves better zero-voltage switching conditions.