Fault Tolerant Multi-Tx/Multi-Rx Inductive Power Transfer System With a Resonator Coil

This article presents a novel multi-transmitter (Tx)/multi-receiver (Rx) inductive power transfer (IPT) system. Compared with the conventional single-Tx/single-Rx systems, multi-Tx/multi-Rx topologies increase reliability and fault tolerance. However, unequal power distribution is challenging in these systems due to coupling differences, which prevents them from operating at rated power or requires overdesigned modules. This study proposes the addition of a middle-stage resonator (MSR) that balances power distribution by separating direct couplings between Tx and Rx coils. Thus, it increases reliability and fault tolerance. Direct couplings between Tx and Rx coils are avoided via the proposed coil structure, which also provides rotational symmetry. Moreover, an analytical method is proposed to avoid bifurcation, which reduces switching losses. Then, the fault tolerance analysis on multi-Tx/multi-Rx systems and optimum selection of module numbers are investigated. Finally, a 1-kW 2Tx/1MSR/4Rx prototype is established to continue operation under single-Tx, single-Rx, and double-Rx open-circuit faults.