Review of Load-Independent Constant-Current and Constant-Voltage Topologies for Domino-Type Multiple-Load Inductive Power Relay System

The ability to concurrently power multiple loads has been a new feature for the inductive power transfer (IPT) system. The domino-type IPT system can not only transfer power over a longer distance but also achieve load-independent outputs. This paper reviews the existing multiple-load IPT systems and aims to provide a methodology to systematically construct suitable domino-type IPT topologies with multiple load-independent constant-current (CC) or constant-voltage (CV) outputs. There are three innovative contributions. First, three resonant circuits are summarized to achieve the compensation network, including the T-type, II-type, and SS topology. Second, 9 CC and 9 CV topologies are proposed, compared, and evaluated as candidates. The optimal CC and CV topologies are identified, and the integrated magnetic coupler designs are provided. Third, the power transfer capability is investigated considering parasitic resistances. The attenuation of load currents/voltages and the efficiency relationship with load resistance, coupling coefficient k, quality factor Q, and receiver number N are analyzed, providing the guideline to design the domino system. A single-input-four-output domino-type IPT system is implemented to validate the effectiveness of the proposed design methodology. Experimental results have shown consistency with the analysis results, and the efficiency can reach 89.79% when k=0.193, Q=320, and N=4.