Circuit Model Based Analysis of a Wireless Energy Transfer System via Coupled Magnetic Resonances

Abstract

A Simple equivalent circuit model is developed for a wireless energy transfer system via coupled magnetic resonances and a practical design method is also provided. Node equations for the resonance system are built with the method, expanding on the equations for a transformer, and the optimum distances of coils in the system are derived analytically for optimum coupling coefficients for high transfer efficiency. In order to calculate the frequency characteristics for a lossy system, the equivalent model is established at an electric design automation tool. The model parameters of the actual system are extracted and the modeling results are compared with measurements. Through the developed model, it is seen that the system can transfer power over a mid-range of a few meters and impedance matching is important to achieve high efficiency. This developed model can be used for a design and prediction on the similar systems such as increasing the number of receiving coils and receiving modules, etc.

High Frequency Fed Unity Power Factor AC-DC Converter For Wireless Power Transfer Applications

“…Transferring energy between wires through magnetic fields is inductive coupling. Magnetic resonant coupling uses the same principles as inductive coupling, but it uses resonance to increase the range at which the energy transfer can efficiently take place [4], [5]. Resonant inductive coupling is the near field wireless transmission of electrical energy between two coils that are tuned to resonate at the same frequency and is depicted in Fig.…”

Magnetic Resonance for Wireless Power Transfer [A Look Back]

“…The 4-coil system in [29] [30] has been analysed by several research groups using standard electric circuit theory [32]- [34]. Reference [32] provides a detailed analysis and an equivalent circuit of this system (Fig. 13).…”

“…Regarding the suggestion of using resonance for efficient energy transfer [29][30], David Schneider commented in the IEEE Spectrum [31] that "It's not a new idea: Tesla's eponymous coils use that very same principle". The 4-coil system in [29] [30] has been analysed by several research groups using standard electric circuit theory [32]- [34]. Reference [32] provides a detailed analysis and an equivalent circuit of this system (Fig.…”

Dosimetry for Resonance-Based Wireless Power Transfer Charging of Electric Vehicles

“…Unlike the conventional magnetic induction technique, The RBWPT technique improves the power transfer distance. Much related research has studied a design method, efficiency characteristics, and so on [2][3][4]. However, the WPT technique produces considerable electric and magnetic fields around the WPT system.…”