Maximum Achievable Efficiency for Multiple-Receiver Inductive Power Transfer Sytems

Reona Sugiyama (1651062)


This work is to establish principles for design and benchmarking multiple-receiver inductive power transfer (IPT) system. We derive the formulas for obtaining optimal loads impedance of multiple-receivers and maximum power transmission efficiency based on N-port network model. Via theoretical analysis, electromagnetic simulation and experiment, we clarify that the cross-coupling among receivers does not deteriorate system efficiency if load resistance and reactance are jointly optimized. We also prove that the maximum efficiency which is newly introduced as system kQ-product in this work, equals to the sum of squares of kQ-product of individual transmitter-receiver link. The efficiency can be expressed by an efficiency angle tangent, in a manner analogous to the well-known kQ-product of single-receiver IPT. In the experimental verification, we measured an extensive S-parameter to validate the derived formulas. This experiment investigated two and three receiver IPT system because of the limitation of equipment, however, these results contribute to establish the kQ-theory for more than four multi-receiver IPT systems.