An Anti-Primary Energy Circulation Control Method in SS-Compensated Multiple Transmitters Dynamic Wireless Power Transfer System Under Heavy Load

Abstract

Dynamic wireless power transfer (DWPT) with multiple transmitters (Multi-Txs) has gained large attention due to the high tolerance of the receiver (Rx) misalignment. However, under Rx-side heavy load conditions, the primary-side energy circulation (PEC) among Txs occurs when the mutual inductances are unbalanced, which deteriorates the transmission efficiency and causes excessive primary current. In this article, an anti-primary energy circulation (APEC) control is proposed. The nature of PEC is first analyzed to be the decreased impedance of the weakly coupled Txs. By adjusting the input voltages of primary resonators, the equivalent impedance of Txs is controlled in real time based on the estimated mutual inductance. The experiment verification is conducted on a 100-W DWPT system with several case studies in different coupling and load conditions. The experimental results prove that the proposed control method can eliminate the PEC in a wide range of load and coupling conditions, and the transmission efficiency can be improved up to 90.44%.