Omnidirectional Free-Degree Wireless Power Transfer System Based on Magnetic Dipole Coils for Multiple Receivers

Abstract

Wireless power transfer (WPT) technology offers a potential solution for the energy-supply problem. In this paper, we propose a novel magnetic coupling mechanism for omnidirectional and multiplepickup energy transfer based on the magnetic dipole coils. Firstly, a cubic transmitter structure capable of generating three-dimension (3D) homogeneous magnetic field is fabricated to weaken directional sensitivity of receiving coil. Furthermore, the direction of current flowing through each dipole coil is also studied in detail. Numerical and simulated analysis is implemented to verify the omnidirectionality of the transmitter. Secondly, the equivalent circuit model for WPT systems with ferrite is analyzed. In addition, optimal loads, power distribution and transfer efficiency for multiple receivers are discussed and used to achieve the proper system design. Finally, experimental prototype is set up to validate the transmission performance of the proposed WPT system. The results have showed that genuine 3D high degree of freedom (DoF) can be achieved. Meantime, above 60% efficiency at least 30 W of total output power can be obtained for WPT systems with eight pick-ups. We believe the proposed system will give a new guideline for future low power electronic applications, such as monitoring sensors, miniature robots and household devices.

2D Omni-Directional Wireless Power Transfer Modeling for Unmanned Aerial Vehicles with Noncollaborative Charging System Control

“…Let By substituting (7) and (8) in the electric Equation ( 6) of the load current of the 2D system, we can derive expressions that describe the input power, the load current, and the power load in terms of the magnetic resultant angle and the angular position of the receiver (α, θ); hence, the complexity imposed by the mutual coupling terms can be solved by replacing M 13 M 23 with their Fourier expressions (7) and ( 8), M 13 (α) and M 23 (α), respectively, thus enabling an accurate control design and simulation for both the 2D and 3D orthogonal WPT systems.…”

“…Similarly, a WPT energy harvester with a multicoil structure was designed to solve the misalignment issue for mobile devices [7]. Additionally, in [8], a cubic magnetic dipole coil structure was proposed to transmit power omnidirectionally, and for multiloads, another research presented a 3D wireless charging cylinder based on two orthogonal coils. The system is able to generate a rotating magnetic field for charging multiple loads [9].…”

“…An iterative algorithm was developed to modulate the resulting magnetic field of the three transmission coils to associate them with a specific target point with large magnetic coupling. However, the downside caused by scaling the charge to multiple loads in the rotational WPT is that the efficiency of the WPT approach will be reduced due to magnetic field leakage issues [8,12]. To overcome the above obstacles and contribute to the development of WPT, technology researchers decided to put forward the possibility of beaming the magnetic field to the target site.…”

C2DD—An omnidirectional receiver based on single‐coil transmitter

“…The double toroidal helix coil Tx can remain transmission efficiency above 90%, 21 but the Rx also need to be made into the double toroidal helix coil which required a certain space, so the application is limited. The coupler was designed as dipole-cross or dipole-cubic, [22][23][24] but the ferrites will increases the volume of Rx. The bowl Tx can be achieved to charge in it, 25 but it will restrict the number and volume of the Rx.…”