Tertiary Coil Design of Wireless Electric Vehicle for Large Misalignment Tolerance

Misalignment tolerance in electric vehicles (EVs) is a critical issue in wireless power transfer (WPT) for EVs. To address this issue, this paper proposes the use of tertiary coil to achieve consistent load power delivery even under severe misalignment conditions. The proposed coil, which incorporates a tertiary winding, is connected in parallel to the receiver (Rx) circuit. This configuration allows the tertiary coil to supply additional power during misalignment instances, while the lone Rx coil receives the load power during central alignment. By employing the proposed tertiary coil, the design of coil can be changed, enabling additional load power delivery across various misalignment scenarios. It is found that the proposed WPT system, which utilizes the 11kW WPT3/Z3 from the J2954 standard, can deliver more than the load power capability of a single coil based WPT system.