Virginia Polytechnic Institute and State University
The LCC is a popular topology in wireless power transfer (WPT) applications, including multi-receiver WPT systems due to robustness and relative insensitivity to misalignments. Output of LCC based WPT systems are typically regulated by an additional dc-dc stage before or after the WPT stage. The additional dc-dc stage increases cost and complexity of the system and would require communication if placed on the transmitter side, making the system susceptible to interference. In this paper, a secondary side modulation scheme based on a variable inductor controlled notch filter is proposed. By modulating the variable inductor, output can be wide-range adjusted independently from the transmitter side. 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 cannot simultaneously accommodate multiple receivers. The proposed system is verified experimentally with a 48-V, 70-W prototype WPT system.
