Evaluation of Inductive Power Transfer System for Mobile Using Receiver-Side Compensation Circuit

In inductive power transfer, series-series (S/S), series-parallel (S/P), parallel-series (P/S), and parallel-parallel (P/P) are common forms of compensation circuits using capacitors. On the other hand, a receiver-side compensation circuit has been proposed that performs impedance compensation only on the receiver side, including the transmitting side. The receiver-side compensation circuit is designed to cancel the reactance component generated between the receiving coil and the transmitting coil. As a result, the power supply and the load are considered to be directly connected, and a stable output voltage can be obtained even if the load resistance fluctuates. In the previous research, SISO system coupling was premised, and the study with multi-coils was not done much. In this study, we propose a inductive power transfer system for mobiles in which the receiver-side compensation circuit is expanded from the conventional SISO system to the MISO system. By arranging power transmission coils in a row and connecting several of them at the same time as receiving coils, high transmission efficiency can be maintained within the power transmission area. Furthermore, in this system, current flows in the power transmission coil only when the power transmission and reception coils are coupled, so it is possible not only to reduce the leakage electromagnetic field but also to automatically switch the power transmission coil without using a sensor. The effectiveness of the proposed method was confirmed by electromagnetic simulation.