Receiver Side Regulation of LCC Wireless Power Transfer System with Variable Notch Filter

The robustness and relative insensitivity to misalignments and mismatches make the LCC topology popular in wireless power transfer (WPT) applications, including more challenging dynamic or multi-receiver WPT systems. The output of LCC topology based WPT systems is typically regulated by an additional dc-dc converter stage, either before or after the WPT stage. The additional dc-dc stage increases the cost and complexity of the system and would require wireless communication for output regulation if placed on the transmitter side, making the system susceptible to electromagnetic interference. In this paper, a receiver side modulation scheme based on a variable inductor controlled notch filter is proposed. By modulating the variable inductor, the output can be independently adjustable in a wide-range. The variable inductor is controlled with simple pulse width modulation (PWM). The proposed control scheme is especially suitable for multi-receiver WPT systems; where transmitter based regulation schemes cannot simultaneously accommodate multiple receivers. The proposed system is verified experimentally with a 48-V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o(max)</inf>, 72-W prototype WPT system with multi-receiver capability.