Alternately Arranged Segmented Transmitter Pads With Magnetic Field Complementation for Suppressing Power Fluctuation in Dynamic Wireless Power Transfer
Xu Hai, Zhicong Huang
Abstract
Dynamic wireless power transfer (DWPT) is a promising solution to address driving range anxiety or eliminate necessity of carrying heavy batteries for electric vehicles (EVs). The DWPT systems are expected to operate satisfactorily with a stable output characteristic over a wide driving range. In this article, a novel transmitter (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm Tx$</tex-math></inline-formula>) track is proposed, which is based on alternately arranged segmented rectangular-solenoid pads. Such a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm Tx$</tex-math></inline-formula> track features magnetic field complementation to suppress the fluctuation of output on the receiver (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm Rx$</tex-math></inline-formula>) side against the wide-range and dynamic displacement. The proposed design allows the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm Tx$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm Rx$</tex-math></inline-formula> pads to have a uniform size, such that the coupling coefficient can be maximized for optimal power transfer capability for a given copper usage and ferrite core. It also allows a wide distance between the adjacent transmitter pads, which further enables the reduction of copper and ferrite core usage and alleviates the cross-coupling issues. In addition, a novel DWPT system with an orthogonal excitation method based on the proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm Tx$</tex-math></inline-formula> track is developed, along with a detailed parameter design methodology. The operation of the proposed DWPT system is purely passive and highly robust, without any necessity for sensing and active control. A 1 kW DWPT experimental prototype is built to verify the proposed DWPT design.