Extensive analysis on wireless power transformer for various core configurations
01 Dec 2015-pp 1-6
TL;DR: This paper demonstrates design aspects and the effects of core dimensions on the coupling factor and illustrates the different core combinations for various WPT models and provides numerical analysis of various factors such as leakage flux, mutual flux and coupling factor.
Abstract: Wireless power transfer (WPT) is one of the safe and convenient way of transmitting power for short range distances. But its efficiency is lower than wired power transfer due to low coupling coefficient and improper coupling between transmitter and receiver. In the field of inductively coupled wireless power transfer, identifying and enabling of appropriate reluctance path between the transmitter and receiver is a significant element. This can be achieved by selecting proper dimensions as well as the suitable category of the core. This paper demonstrates design aspects and the effects of core dimensions on the coupling factor and illustrates the different core combinations. It also provides numerical analysis of various factors such as leakage flux, mutual flux and coupling factor and the similar attributes for various WPT models. In this work, various core combinations have been analyzed to find an efficient combination to achieve highest coupling coefficient to facilitate maximum power transfer in the system. The WPT system is further analyzed under no-load as well as load conditions for various distances between transmitter and receiver.
Citations
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01 Dec 2017
TL;DR: In this paper, a detailed mathematical analysis of various coil structures has been presented and observed the change in inductance from one coil structure to another and the effect of coil structure on self-inductance, mutual inductance and coupling factor between the coils.
Abstract: Wireless Power Transfer System (WPTS) is gaining more attention across low power to high power applications. It is a convenient, safer, reliable, and user-friendly solution to wireless Electric Vehicle (EV) charger users. In WPTS, large air-gap between coils may cause high leakage of magnetic fields and it may also lower the coupling factor (k). In such systems, selection of coil structure and core configuration plays a key role to reduce the magnetic leakage. In this paper, a thorough mathematical analysis of various coil structures has been presented and observed the change in inductance from one coil structure to another. A finite element method is used in this paper to study the effect of coil structure on self-inductance, mutual inductance and coupling factor between the coils. This paper also provides the numerous core configurations, which have been added to WPTS and simulated to find its effect on power transfer efficiency between transmitter and receiver. The analysis on various coil-core configurations are performed for distinct air gaps between the transmitter and the receiver and found the supreme coil-core configuration to achieve the better coupling between them.
1 citations
Cites background from "Extensive analysis on wireless powe..."
...Since the coupling factor (k) is majorly depended on the value of mutual inductance (M), it is important to increase the value of M between the coils by reducing the leakage present in the system [7]....
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04 Aug 2022
TL;DR: In this article , a new coil structure based on the dimensions specified by Qi standards is proposed and a detailed geometric analysis for 2-coil WPT system is presented, and three different coil structures are simulated to attain the good coupling factor using magnetic resonant coupling technique.
Abstract: Wireless Power Transfer (WPT) Technology is proliferating the domain of battery based devices and machines for its ability to offer higher security and mobility while charging. WPT is yet to mature in terms of Power Transfer Efficiency (PTE) and Transferred Power (TP). WPT finds huge application in electric vehicles, medically-implanted devices and consumer electronics like laptops and mobile phones. The wireless mobile charging products follow Qi standards, released by Wireless Power Consortium. In this paper, a new coil structure is proposed based on the dimensions specified by Qi standards. A detailed geometric analysis for 2-coil WPT system is presented. Furthermore, three different coil structures are simulated to attain the good coupling factor using magnetic resonant coupling technique. A new coil structure called triple-layered square spiral coil is proposed to achieve better output in terms of coupling factor. The simulations results are compared and the significant results are highlighted.
04 Aug 2022
TL;DR: In this paper , a new coil structure based on the dimensions specified by Qi standards is proposed to achieve better output in terms of coupling factor, and three different coil structures are simulated to attain the good coupling factor using magnetic resonant coupling technique.
Abstract: Wireless Power Transfer (WPT) Technology is proliferating the domain of battery based devices and machines for its ability to offer higher security and mobility while charging. WPT is yet to mature in terms of Power Transfer Efficiency (PTE) and Transferred Power (TP). WPT finds huge application in electric vehicles, medically-implanted devices and consumer electronics like laptops and mobile phones. The wireless mobile charging products follow Qi standards, released by Wireless Power Consortium. In this paper, a new coil structure is proposed based on the dimensions specified by Qi standards. A detailed geometric analysis for 2-coil WPT system is presented. Furthermore, three different coil structures are simulated to attain the good coupling factor using magnetic resonant coupling technique. A new coil structure called triple-layered square spiral coil is proposed to achieve better output in terms of coupling factor. The simulations results are compared and the significant results are highlighted.
References
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TL;DR: A high-power high-efficiency wireless-power-transfer system using the class-E operation for transmitter via inductive coupling has been designed and fabricated using the proposed design approach.
Abstract: In this paper, a high-power high-efficiency wireless-power-transfer system using the class-E operation for transmitter via inductive coupling has been designed and fabricated using the proposed design approach. The system requires no complex external control system but relies on its natural impedance response to achieve the desired power-delivery profile across a wide range of load resistances while maintaining high efficiency to prevent any heating issues. The proposed system consists of multichannels with independent gate drive to control power delivery. The fabricated system is compact and capable of 295 W of power delivery at 75.7% efficiency with forced air cooling and of 69 W of power delivery at 74.2% efficiency with convection cooling. This is the highest power and efficiency of a loosely coupled planar wireless-power-transfer system reported to date.
520 citations
"Extensive analysis on wireless powe..." refers methods in this paper
...The self – flux ∅ in the primary coil is determined by ∅ = ( ∅ ) (1) The mutual flux ∅ in the primary coil due to current flowing in the secondary coil is determined by using the equation VS = ω NS ∅M (2) From the equations (1) and (2), the leakage flux ∅ referred to primary can be determined by ∅ = ∅ − ∅ (3) The self - inductance of the primary coil is given by LP = NP ∅P IP (4) The mutual inductance (M) can be calculated by using the equation NS ∅M = M IP (5) From (4) and (5) the primary leakage inductance , can be calculated by Lpl = LP − M (6) In the same manner, secondary side parameters can be calculated using similar equations....
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TL;DR: Although the presented power supply with a rotatable transformer is constructed mainly for robotics and manipulators, the described design and control methodology has general validity and can be applied for a wide class of contactlessPower supply with core or coreless transformers.
Abstract: Power supply based on an inductive coupled contactless energy transfer system is presented in this paper. The energy is transferred using a rotatable transformer and a power electronic converter. To minimize total losses of the system, a series resonant compensation circuit is applied assuring zero-current switching condition for insulated-gate bipolar transistors. The analytical expression of the transfer dc voltage gain is presented and discussed. The novelty of the system lies in the application of a fully digital field-programmable-gate-array-based controller and a protection system. The resonant frequency is adjusted by a primary peak current regulator. Some simulation and experimental results illustrating the operation of the developed 3-kW 60-kHz laboratory prototype are given. Although the presented power supply with a rotatable transformer is constructed mainly for robotics and manipulators, the described design and control methodology has general validity and can be applied for a wide class of contactless power supply with core or coreless transformers.
251 citations
"Extensive analysis on wireless powe..." refers background in this paper
...By comparisons of two contour flux plots shown in Figs 5 and 7 it can be found that the amount of leakage flux is lesser in Fig (7)....
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...The coupling factors referred to primary and secondary coils are given by kP = ∅M ∅P kS = ∅M ∅S (7)...
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15 May 2013
TL;DR: In this article, the authors developed a simple theoretical model for ICW power transfer and compared it with 3D Electromagnetic simulations of an inductive link system to ICs.
Abstract: With the trend of portable electronics to go battery-less, Inductive Coupling Wireless Power Transfer (ICW Power Transfer) is becoming commonplace. Inductive Coupling has shown to be a good technique for proximity and wireless power transfer in general, because it permits the easy use of impedance matching and resonance circuits. An important potential application is powering Integrated Circuits (ICs) from a PCB (Printed Circuit Board) without using conductive pins. While using ferromagnetic core materials improves coupling, conductive non-ferromagnetic ones like most IC's substrates, decrease coupling and ICW Power Transfer performance. In this paper we developed a simple theoretical model for ICW power transfer and compared it with 3D Electromagnetic simulations of an inductive link system to ICs. The results show that enough power can be supplied to very low power consumption ICs. As this technique can be also used to perform wireless communications, it opens the possibility to design ICs without pins at all.
37 citations
"Extensive analysis on wireless powe..." refers methods in this paper
...The self – flux ∅ in the primary coil is determined by ∅ = ( ∅ ) (1) The mutual flux ∅ in the primary coil due to current flowing in the secondary coil is determined by using the equation VS = ω NS ∅M (2) From the equations (1) and (2), the leakage flux ∅ referred to primary can be determined by ∅ = ∅ − ∅ (3) The self - inductance of the primary coil is given by LP = NP ∅P IP (4) The mutual inductance (M) can be calculated by using the equation NS ∅M = M IP (5) From (4) and (5) the primary leakage inductance , can be calculated by Lpl = LP − M (6) In the same manner, secondary side parameters can be calculated using similar equations....
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01 Sep 2013
TL;DR: In this article, the design procedure of the coils of a CETS intended to charge the battery pack of electric city car is presented, and the results of the numerical analysis are validated by the outcomes of finite element method and power circuit simulation simulations.
Abstract: Inductive contactless energy transfer systems (CETS) transfer electric energy between their input and output section without any wired connection. The coupling device consists of two coils whose setup is a crucial issue in building up a CETS. This paper presents the design procedure of the coils of a CETS intended to charge the battery pack of electric city car. The procedure encompasses the determination of the inductive parameters of the coils when ferrite cores with different geometries are considered. Topology and sizing of the power inverter supplying the transmitter coils are also addressed. The results of the numerical analysis are validated by the outcomes of finite element method and power circuit simulation simulations.
16 citations
"Extensive analysis on wireless powe..." refers methods in this paper
...The self – flux ∅ in the primary coil is determined by ∅ = ( ∅ ) (1) The mutual flux ∅ in the primary coil due to current flowing in the secondary coil is determined by using the equation VS = ω NS ∅M (2) From the equations (1) and (2), the leakage flux ∅ referred to primary can be determined by ∅ = ∅ − ∅ (3) The self - inductance of the primary coil is given by LP = NP ∅P IP (4) The mutual inductance (M) can be calculated by using the equation NS ∅M = M IP (5) From (4) and (5) the primary leakage inductance , can be calculated by Lpl = LP − M (6) In the same manner, secondary side parameters can be calculated using similar equations....
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