Multifrequency Phase-Shifted Control for Multiphase Multiload MCR WPT System to Achieve Targeted Power Distribution and High Misalignment Tolerance

Abstract

With urgent market demand for multiload electronic applications, multiload magnetically coupled resonant (MCR) wireless power transfer (WPT) system has caused widespread concern. In the practical applications, multiload MCR WPT system should have the capability to realize targeted power distribution among loads and stable output power against misalignment of load. To achieve this goal, a multiphase multifrequency system with multiple loads is proposed in this article, where multi-phase structure of transmitting coils can enhance the misalignment tolerance, and multiple operating frequencies are beneficial to achieve multiload identification and targeted power distribution. For simplicity, this article mainly studies a two-phase dual-frequency system with two loads and proposes two phase-shifted control strategies. The equivalent circuit model of the system is established, and the output power in the open-loop system under two phase-shifted control methodologies are analyzed. According to that, the targeted power distribution strategy by adjusting the resonant frequency of the transmitter is implemented. Moreover, the closed-loop control schemes based on phase-shifted control methodologies are adopted to realize stable output power precisely against the misalignment of loads. Finally, a prototype of two-phase dual-frequency MCR WPT system with two loads is built in the laboratory. The experimental results prove the correctness of the theoretical analysis.