An Active Shielding Control Method for a Wireless Power Transfer System under Misalignment Conditions

This paper proposes a control method for an active shield system using an independent power source under misalignment conditions. The proposed method controls the current strength and phase of the shielding system according to magnetic field leakage characteristics with high shielding performance (SP) under misalignment conditions. The current strength and phase of the shielding system were determined by the current strength and mutual inductance of the wireless power transfer (WPT) and shielding coils. Additionally, we considered x and y misalignment conditions and analyzed SP and power transfer efficiency (PTE). The proposed method was verified through simulations and experiments in terms of SP and PTE. The experiments confirmed that, due to the shielding system control, SP increased from 49.22% to 61.74% under misalignment conditions, but there was no additional PTE reduction due to shielding coil control under these conditions.