Computation of the Mutual Inductance between Air-Cored Coils of Wireless Power Transformer

Increase in Robustness against Effects of Coil Misalignment on Electrical Parameters Using Magnetic Material Layer in Planar Coils of Wireless Power Transfer Transformer

“…The next step is to consider misalignment between the coils. Anele et al presented solutions for circular coils with lateral and angular misalignment and presented a mutual inductance equation based on elliptical integrals [27]. A similar approach was used by Lee and Lorentz [17], but for the case of coil being a hollow cylinder.…”

“…A similar approach was used by Lee and Lorentz [17], but for the case of coil being a hollow cylinder. Equation (1) presents the mutual inductance of a circular coil in air [27]:…”

“…in which d is the lateral misalignment, θ is the angular misalignment, R p and R s are the distances from the centers of the coils to the reference axis, respectively, and ϕ is the integration angle at any point on the secondary coil. A diagram representing these equations can be found in the study of Anele et al [27].…”

“…From the perspective of the electrical circuit, the model presented by Steinmetz [25] was used, due to the simplicity of it. From the point of view of the magnetic analysis, the Maxwell Equations [26] were used, following the interpretation gave by Anele et al [27], Su et al [28] and the approach of Luo et al [29] to use the magnetic vector potential to calculate the mutual inductance.…”

Mutual inductance calculation for coils with misalignment in wireless power transfer

“…WPT systems allow electrical power to be transmitted between transmitting coil and receiving coil using high‐frequency magnetic fields [5, 6]. During the transmission, the coupling relationship between the two coils is established, which is usually measured by coupling coefficient.…”