A Multifrequency Superposition Methodology to Achieve High Efficiency and Targeted Power Distribution for a Multiload MCR WPT System

Magnetically coupled resonant (MCR) wireless power transfer (WPT) is one of the most promising WPT technologies for its remarkable capability of simultaneous noncontact power transfer for multiple independent loads. Nevertheless, diverse energy requirements of different loads and efficiency quota make it difficult to design and optimize the multiload system. In this paper, a novel driver configuration for the MCR WPT system with multiple loads is proposed, in which the transmitting resonant tank is driven synchronously by multiple inverters operating at multiple switching frequency and sharing a common dc voltage source, then a multifrequency superposition methodology is presented to achieve high efficiency and targeted power distribution. The dominant features of the methodology are listed as follows: 1) the multifrequency power components from multiple inverters can be simultaneously delivered to multiple loads through a single transmitter; 2) the receiving coils are elaborately designed at different resonant frequencies that correspond to the operating frequencies of multiple inverters to achieve targeted power transfer and high efficiency; 3) the resonant frequency of the transmitter can be modulated within the adjacent area of multiple operating frequencies, and the power distribution to meet the requirements of selective loads will be realized; and 4) the resonant frequencies of receivers can also be adjusted to effectively realize the power distribution. In this paper, a double-frequency MCR WPT system with two loads is comprehensively investigated as a representative example, and the studied methodology has been experimentally verified by two prototypes of the proposed circuit configurations.