Transfer-Power Measurement Using a Non-Contact Method For Fair and Accurate Metering of Wireless Power Transfer in Electric Vehicles

Wireless power transfer is emerging as the preeminent way to charge electric vehicles, but there appears to be no fair way to measure the power transfer. In this paper, Faraday Coil Transfer-Power Measurement (FC-TPM) is presented. FC-TPM employs non-contact, open-circuited sense coils to measure the electromagnetic field from wireless power transfer and calculates the real power propagating through the air gap between the transmitter and receiver coils. What is measured is the real electromagnetic power, representing the pure dispensation of energy that unambiguously demarcates the losses on either side. FC-TPM was demonstrated to be 0.1% accurate in hardware over an Rx coil misalignment of up to 10 cm using a 1 kW wireless power transfer system. Fair metering incentivizes businesses and individuals to make choices that conserve energy and advance technology by providing more information and by properly assigning the financial loss. This paper is accompanied by a video highlighting the essential contributions of this paper.