Analysis and Parameter Design for Input-Series Output-Series (ISOS) Multichannel Inductive Power Transfer System Considering Cross Coupling

Nowadays, a higher capability of voltage and power is needed in scenarios such as shore-based power system and electric vehicles charging. Input-series output-series (ISOS) multichannel inductive power transfer (IPT) system, due to its flexibility and reliability, has become a promising way. To get a more generalized realization of the proposed system, the effect of cross coupling is analyzed theoretically and corresponding elimination method is proposed in this article. First, a numerical expression to describe the input impedance of each channel is figured out and the influence of cross coupling is analyzed. It shows that cross coupling causes difference in phase angles of input impedance among different inverters, which produces a strong output inconsistency among channels, especially under large-load condition. Then, to eliminate the harmful effect of cross coupling, a parameter design principle is proposed based on the equivalent impedance compensation without any additional circuit components or control loop. Finally, a 2.81-kW down-scale three-channel prototype was built to confirm the effectiveness of the proposed principle. The experimental results show that the phase angle imbalance of the compensated system gets eliminated with the maximum difference being just 2.3°, which makes the channels get equivalently decoupled from each other and the system easier for implementation.