An Improved Wireless Battery Charging System

Lee, Wooseok; Kim, Jin-Hak; Cho, Shin-Young; Lee, Il-Oun

doi:10.3390/en11040791

Cited by 2 publications

(3 citation statements)

References 23 publications

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“…1. the SS architecture sets the sinusoidal current amplitude I SM to the secondary side when the primary circuit is supplied with a sinusoidal voltage source at its natural resonance frequency f ss , as indicated in [16]. Therefore, the WPT system is seen from the secondary side as an ideal sinusoidal current generator [15]; 2. the bridge rectifier diodes are ideal with no voltage drop and series-resistance.…”

Section: Secondary Load Characterizationmentioning

confidence: 99%

“…The biquadratic equation in ( 15) is obtained by substituting (2) in (14). The roots ω 1,2 of the equation are reported in (16).…”

Section: Effects Of the Wpt Excitation Frequency On The Load Impedancementioning

confidence: 99%

“…Furthermore, the SS WPT charging system behaves as a current generator [15], which is a good feature to realize a battery charger. Hence, the battery can directly be charged without dedicated regulation circuits and the charging current is established from the primary side [16]. Generally, the weight of the charger section on board the drone can be diminished by increasing the WPT excitation frequency or reducing the number of components.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the Sizing of the DC-Link Capacitor to Increase the Power Transfer in a Series-Series Inductive Resonant Wireless Charging Station

et al. 2021

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Wireless inductive-coupled power transfer is a very appealing technique for the battery recharge of autonomous devices like surveillance drones. The charger design mainly focuses on lightness and fast-charging to improve the drone mission times and reduce the no-flight gaps. The charger secondary circuit mounted on the drone generally consists of a full-bridge rectifier and a second-order filter. The filter cut-off frequency is usually chosen to make the rectifier output voltage constant and so that the battery is charged with continuous quantities. Previous works showed that an increase in power transfer is achieved, if compared to the traditional case, when the second-order filter resonant frequency is close to the double of the wireless charger excitation and the filter works in resonance. This work demonstrates that the condition of resonance is necessary but not sufficient to achieve the power increment. The bridge rectifier diodes must work in discontinuous-mode to improve the power transfer. The paper also investigates the dependence of the power transfer increase on the wireless excitation frequency. It is found the minimum frequency value below which the power transfer gain is not possible. This frequency transition point is calculated, and it is shown that the gain in power transfer is obtained for any battery when its equivalent circuit parameters are known. LTSpice simulations demonstrate that the transferred power can be incremented of around 30%, if compared to the case in which the rectifier works in continuous mode. This achievement is obtained by following the design recommendations proposed at the end of the paper, which trade off the gain in power transfer and the amplitude of the oscillating components of the wireless charger output.

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Section: Secondary Load Characterizationmentioning

confidence: 99%

“…The biquadratic equation in ( 15) is obtained by substituting (2) in (14). The roots ω 1,2 of the equation are reported in (16).…”

Section: Effects Of the Wpt Excitation Frequency On The Load Impedancementioning

confidence: 99%