The capacitor regulator for maximizing wireless power transfer efficiency in retuned resonant state

Xu, Jinxin; Zheng, Cong; Cheng, Yuxuan

doi:10.1002/mmce.22239

Cited by 4 publications

(6 citation statements)

References 17 publications

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“…The use of duty cycle-controlled capacitor regulators for tuning IPT systems has been shown before, and the performance of the proposed SC network is compared with other work in Table 4. Systems in [26,30,31,33] share some commonalties, (1) low resonant frequency (typically 100 kHz), (2) relatively tight coupling, and (3) capacitance adjusted by duty cycle. This duty cycle control achieves continuous and precise tuning such that the system has minimal power drop.…”

Section: Comparisonmentioning

confidence: 99%

“…There are a number of methods to retune the primary resonant tank including inductance variations through mechanical core movement [5–7], magnetic saturation [8–11], or switched inductor [12–15]; but capacitance variations through continuously variable capacitor or switched capacitor (SC) [16–36] are most common due to their small size and low price relative to inductors. The continuous variable tuning inductor or capacitor method is widely used as it allows cycle‐by‐cycle compensation for fast transient loads or impedance variation.…”

Section: Introductionmentioning

confidence: 99%

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Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingC_OSS

Jin

Gallichan

Budgett

et al. 2023

IET Power Electronics

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High Q coils are required by inductive power transfer (IPT) links to attain reasonable levels of power transfer especially for loosely coupled links such as those used for small, deeply implanted medical devices. However, the high Q feature makes IPT systems strongly dependent on operating frequency which must be matched in the primary and secondary resonant tanks. Consequently, power transfer is sensitive to resonant frequency shifts due to component aging and environmental factors. Here, a switched capacitor (SC) network is developed to maintain tight matching and enhance system robustness. The combination of high voltage and high frequency required to achieve power transfer to deeply implanted devices makes the SC network design challenging. High frequencies require small tuning capacitance and high voltage requires MOSFETS with large output capacitance (COSS) resulting in COSS having a significant effect on tuning frequency. This paper proposes a parameter design method incorporating COSS to eliminate the uncertainty of voltage related COSS. In the experiment, the SC network broadens the effective bandwidth from 37 to 585 kHz at the centre frequency of 6.50 MHz. Across a frequency sweep, the worst case in transfer power drop is −0.43 dB, which demonstrates sufficient immunity to parameter deviations.

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Section: Comparisonmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingC_OSS

Jin

Gallichan

Budgett

et al. 2023

IET Power Electronics

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“…From the approximate expressions of mutual inductances shown in formulas (17) to (20), since the receiving coil and the transmitting coil have a one-to-one correspondence in four directions, the mutual inductance M 1~M4 will shows different trends with changing the offset direction of the receiving end, which can be used to determine the specific offset direction of the load end (such as the electric vehicle) parking position, and can approximately estimate the horizontal offset distance d 0 , d 1 when d 2 is determined.…”

Section: Overview Of Positioning Strategies For Coil Structuresmentioning

confidence: 99%

“…To explore the effect of mutual inductance of the proposed coil structure on improving the transmission coupling state of the wireless charging system, we made a schematic diagram of its equivalent circuit topology based on the structure diagram of the wireless charging system shown in Figure 2, as shown in Figure 6 17 . Among them, M is the mutual inductance value between the coupling coils, U P represents the effective value of the voltage of the equivalent AC power supply whose working frequency is ω , I P , and I S respectively represent the primary and secondary currents, Z P and Z S represent the line impedance of the primary and secondary sides, R W represents the resistance value of the resistive load.…”

Section: Principle Of Mutual Inductance Of Spiral Coilmentioning

confidence: 99%

A new coil structure for positioning estimate of wireless power transmission

Zou

Zheng

2020

Int J RF Microw Comput Aided Eng

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Accurate positioning is certainly essential in wireless power transmission (WPT) for the improvement of transmission efficiency. This article proposes a novel positioning coil structure for the WPT system, which determines the offset direction of the transmitter and receiver using the principle of mutual inductance. First, a new wireless positioning structure and parameters are designed. Then, the theoretical formulas are derived, which help to obtain the functional relationships between coils and distances. According to the various mutual inductances of the proposed positioning structure, how to determine the specific offset direction of the receiver is further discussed. Meanwhile, the intensity of the magnetic field between the transmitter and receiver is simulated. Finally, the hardware experiment platform is established to verify the theory. The simulation and experimental results show that the coil structure effectively realizes the determination of the load deviation direction. This method is of practical significance in realizing the precise positioning of the transmitter and receiver, which enable the creation of novel reconfigurable devices as potential applications.

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“…Nowadays, the growing number of wireless sensor has increased the demand of WPT technique 2 . Compared to magnetically coupled inductive wireless power transfer, 3 microwave wireless power transfer (MWPT) has a significant advantage to realize wireless power transfer through space over a longer distance 4 …”

Section: Introductionmentioning

confidence: 99%

A compact hollowed‐out loop rectenna without matching network for wireless sensor applications

Jing

Pang

Wang

et al. 2020

Int J RF Microw Comput Aided Eng

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In this article, a compact and high-efficiency loop rectenna with matching network elimination for wireless sensor applications at 2.45 GHz is presented. The proposed hollowed-out square loop antenna is designed and directly provides a conjugate matching to a compact voltage-doubler rectifier. The loop rectenna can harvest microwave power without increasing the total size or affecting the performance of a wireless sensor. The experiment results show that the peak microwave-to-dc conversion efficiency of 74% is obtained at 2.45 GHz when the input power is 18 dBm. The dimension of rectenna is 30 × 30 × 1 mm 3 and only with a weight of 0.58 g, which successfully realizes a high power-weight-ratio (PWR). Hence, the proposed rectenna can provide a convenient and practical charging solution for wireless sensors in various applications.

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The capacitor regulator for maximizing wireless power transfer efficiency in retuned resonant state

Cited by 4 publications

References 17 publications

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingC_OSS

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingC_OSS

A new coil structure for positioning estimate of wireless power transmission

A compact hollowed‐out loop rectenna without matching network for wireless sensor applications

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The capacitor regulator for maximizing wireless power transfer efficiency in retuned resonant state

Cited by 4 publications

References 17 publications

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingCOSS

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingCOSS

A new coil structure for positioning estimate of wireless power transmission

A compact hollowed‐out loop rectenna without matching network for wireless sensor applications

Contact Info

Product

Resources

About

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingC_OSS

Retuning high Q inductive power transfer systems at MHz frequencies: a switched capacitor design method incorporatingC_OSS