WO2017131532A1 - Émetteur de puissance inductive - Google Patents

Émetteur de puissance inductive Download PDF

Info

Publication number
WO2017131532A1
WO2017131532A1 PCT/NZ2017/050007 NZ2017050007W WO2017131532A1 WO 2017131532 A1 WO2017131532 A1 WO 2017131532A1 NZ 2017050007 W NZ2017050007 W NZ 2017050007W WO 2017131532 A1 WO2017131532 A1 WO 2017131532A1
Authority
WO
WIPO (PCT)
Prior art keywords
power
transmitter
inductive power
frequency
lcl
Prior art date
Application number
PCT/NZ2017/050007
Other languages
English (en)
Inventor
Saining Ren
James Duncan Deans GAWITH
Original Assignee
Powerbyproxi Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Powerbyproxi Limited filed Critical Powerbyproxi Limited
Publication of WO2017131532A1 publication Critical patent/WO2017131532A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
    • H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type

Definitions

  • This invention relates generally to a converter, particularly though not solely, to a converter for an inductive power transmitter.
  • a converter converts a supply of a first type to an output of a second type.
  • Such conversion can include DC-DC, AC-AC and DC-AC electrical conversions.
  • a converter may have any number of DC and AC 'parts', for example a DC-DC converter might incorporate an AC-AC converter stage in the form of a transformer.
  • IPT inductive power transfer
  • IPT systems will typically include an inductive power transmitter and an inductive power receiver.
  • the inductive power transmitter includes a transmitting coil or coils, which are driven by a suitable transmitting circuit to generate an alternating magnetic field.
  • the alternating magnetic field will induce a current in a receiving coil or coils of the inductive power receiver.
  • the present invention may provide an improved inductive power transmitter or which provides the public with a useful choice.
  • an inductive power transmitter comprising: an LCL circuit which includes a transmitter coil; and a power inverter including a plurality of control devices configured to drive the LCL circuit; wherein the frequency of a plurality of drive signals for the respective control devices is determined based on a desired power factor for the LCL circuit.
  • Figure 1 is a block diagram of an inductive power transfer system
  • Figure 2 is a circuit diagram of an example transmitter
  • Figure 3 is a further circuit diagram of an example transmitter
  • Figure 4 is a graph of example voltage waveforms
  • Figure 5 is graph of a transmitter with a lagging power factor
  • Figure 6 is graph of a transmitter with zero voltage switching
  • Figure 7 is graph of a transmitter with a leading power factor
  • Figure 8a is a circuit diagram of a system with 0.26 coupling
  • Figure 8b is a circuit diagram of a system with 0.5 coupling
  • Figure 9a is a graph of a system with 0.3 coupling
  • Figure 9b is a graph of a system with 0.6 coupling
  • Figure 10 is a schematic of a first control strategy
  • Figure 11 is a schematic of a second control strategy
  • Figure 12 is a schematic of a third control strategy.
  • the IPT system 1 includes an inductive power transmitter 2 and an inductive power receiver 3.
  • the inductive power transmitter 2 is connected to an appropriate power supply 4 (such as mains power or a battery).
  • the inductive power transmitter 2 may include transmitter circuitry having one or more of a converter 5, e.g., an AC-DC converter (depending on the type of power supply used) and an inverter 6, e.g., connected to the converter 5 (if present).
  • the inverter 6 supplies a transmitting coil or coils 7 with an AC signal so that the transmitting coil or coils 7 generate an alternating magnetic field.
  • the transmitting coil(s) 7 may also be considered to be separate from the inverter 5.
  • the transmitting coil or coils 7 may be connected to capacitors (not shown) either in parallel or series to create a resonant circuit. Additional coils may be provided, for example in an LCL configuration.
  • a controller 8 may be connected to each part of the inductive power transmitter 2.
  • the controller 8 may be adapted to receive inputs from each part of the inductive power transmitter 2 and produce outputs that control the operation of each part.
  • the controller 8 may be implemented as a single unit or separate units, configured to control various aspects of the inductive power transmitter 2 depending on its capabilities, including for example: power flow, tuning, selectively energising transmitting coils, inductive power receiver detection and/or communications.
  • the inductive power receiver 3 includes a power pick up stage 9 connected to power conditioning circuitry 10 that in turn supplies power to a load 11.
  • the power pick up stage 9 includes inductive power receiving coil or coils. When the coils of the inductive power transmitter 2 and the inductive power receiver 3 are suitably coupled, the alternating magnetic field generated by the transmitting coil or coils 7 induces an alternating current in the receiving coil or coils.
  • the receiving coil or coils may be connected to capacitors (not shown) either in parallel or series to create a resonant circuit. Additional coils may be provided, for example in an LCL configuration.
  • the receiver may include a controller 12 which may control tuning of the receiving coil or coils, operation of the power conditioning circuitry 10 and/or communications.
  • coil may include an electrically conductive structure where an electrical current generates a magnetic field.
  • inductive “coils” may be electrically conductive wire in three dimensional shapes or two dimensional planar shapes, electrically conductive material fabricated using printed circuit board (PCB) techniques into three dimensional shapes over plural PCB 'layers', and other coil-like shapes. Other configurations may be used depending on the application.
  • PCB printed circuit board
  • IPT inductive power transfer
  • the inductive power transmitter 2 and/or the inductive power receiver 3 may be resonant or non-resonant.
  • Resonant power transfer has the advantage that the range of power transfer can be increased, compared to non-resonant transfer.
  • Resonant topologies may include series resonant circuits or parallel resonant circuits.
  • Another topology is LCL, which is a combination of both series and parallel tuning that uses at least two inductors and at least one capacitor.
  • LCL is a combination of both series and parallel tuning that uses at least two inductors and at least one capacitor.
  • Each option has pros and cons.
  • a series tuned transmitting coil or coils 7 can appear as a low impedance load at its tuned frequency and a high impedance load at higher frequencies due to the series inductive element. Because of this the series tuned transmitting coil or coils 7 can draw significant current from the inverter 6 when being driven at the resonant frequency, even when a low inverter 6 output voltage is used.
  • a parallel tuned transmitting coil or coils 7 can appear as a high impedance load at its tuned frequency and a low impedance load at higher frequencies due to the parallel capacitive element.
  • This is inherently not well suited for use with voltage source inverters 6 such as a full bridge inverter, because the voltage source inverter will typically try to force its output voltage to rapidly switch from one value to another.
  • This rapidly changing voltage in parallel with the parallel tuning capacitor of the transmitting coil or coils 7 can result in large transient currents which can damage the inverter 6.
  • An LCL tuned transmitting coil or coils 7 has a combination of the desirable input and output characteristics of the parallel and series tuned transmitting coil or coils 7 and also has fewer downsides.
  • the inductive power transmitter 2 can maintain a current flowing in the transmitting coil or coils 7 without needing to switch high currents through the switches of the inverter 6, even when the inverter 6 is a voltage source inverter.
  • An LCL tuned transmitting coil or coils 7 may allow power transfer at unity power factor when driven with a voltage source inverter. That is the real power flowing into the LCL tuned transmitting coil or coils 7 network from the inverter 6 can be substantially equal to the apparent power.
  • an IPT system 1 can be implemented with an LCL tuned power transmitting coil or coils 7 and an LCL tuned power pick up stage 9.
  • IPT in particular to a rotating IPT coupling for industrial applications eg: a wind turbine, it may be desirable to operate the transmitter and receiver in a tuned manner. This may reduce the reactive current flowing in the inverter 6 circuitry by operating at close to unity power factor, which may increase efficiency and allow for lower component ratings. It may also enable zero voltage switching in relation to the inverter 6 and/or any rectifiers within the power conditioning circuitry 10, which may further increase efficiency and/or reduce component stress.
  • a change is a change in the coupling coefficient between the transmitter coil or coils 7 and the receiver coil or coils. This may happen due to a change in distance between the inductive power transmitter 2 and the inductive power receiver 3.
  • Retuning of the tuned networks can be done in a numbers of ways; the particular methodology can be chosen according to the requirements of the application.
  • One example for retuning is to modify the IPT frequency of the transmitter to the new "resonant" frequency, or to another frequency somewhat above or below the resonant frequency as required by the application.
  • Changes in the transmitting frequency can be used to tune the transmitting coil or coils 7, the power pick up stage 9 or to tune some combination of the two.
  • FIG. 2 shows an example of an inverter 6 which uses LCL tuned circuit 201.
  • the inverter includes switches SI 202, S2 203, S3 204 and S4 205.
  • a DC source 206 is shown here for simplicity but would in practice be provided by the converter 5 or from a power supply 4.
  • a transmitting coil or coils 7 is connected first in series with a series tuning capacitor 207, the combination of which is then connected in parallel with a parallel tuning capacitor 208. This is then connected to a series tuning inductor 209 which is in turn connected to switches S2 203 and S4 205 of the inverter 6.
  • Switches SI 202 and S3 204 drive the first leg 210 of the LCL tuned circuit 201 and switches S2 203 and S4 205 drive the second leg 211.
  • the driving voltage 212 to the LCL tuned circuit 201 is the voltage difference between the first leg 210 and the second leg 211.
  • the current flowing into the LCL tuned circuit 201 flows through the series tuning inductor 209 and is denoted the driving current 213.
  • the body diodes 214 of the switches SI 202, S2 203, S3 204 and S4 205 are explicitly shown however in practice these will typically be a part of the switches, which will typically be MOSFETs. However, it is also possible to use other device types such as but not limited to bipolar junction transistors, silicon carbide FETs, gallium nitride FETs or IGBTs.
  • An LCL tuned circuit 201 should comprise a transmitting coil or coils 7, a parallel tuning capacitor 208 and a series tuning inductor 209.
  • the values of the components should be chosen for a resonant frequency.
  • This tuned frequency may for example be the designated IPT frequency, or frequency range, or it may be shifted from that depending on the application requirements.
  • the reactance of each branch should be matched.
  • the series tuning inductor 209 is the same reactance as parallel tuning capacitor 208 which must be the same reactance as the combination of transmitting coil 7 and the series tuning capacitor 207.
  • FIG 3 shows an implementation of an LCL tuned transmitting coil or coils 7 with a full bridge inverter 6. Waveforms for a possible mode of operation of this circuit are shown in Figure 4.
  • all of switches SI 202, S2 203, S3 204 and S4 205 run at approximately 50% duty cycle with a small dead- time.
  • the switches that are connected to a given leg of the LCL tuned circuit 201, for example SI 202 and S3 204 for the first leg 210, are operated at 180 degrees out of phase from each other.
  • the effective duty cycle of the inverter 6 is controlled by changing the phase angle between drive voltages applied to the switches on one side of the bridge (202 and 204) versus the other side of the bridge (203 and 205).
  • the inductive power transmitter 2 can control the power being transmitted.
  • a low effective duty cycle can be ideal for light loads and/or when the transmitting coil or coils 7 and the power pick up stage 9 are tightly coupled.
  • the driving voltage 212 can be approximated as the effective duty cycle multiplied by the voltage of the DC source 206.
  • the power factor of the LCL tuned circuit 201 is the phase angle between the driving voltage 212 and the driving current 213.
  • a leading power factor means the current leads the voltage by some phase and implies a capacitive load, while a lagging power factor means current lags the voltage and implies an inductive load.
  • Designing the LCL tuned circuit 201 to operate at a certain power factor can be advantageous. For example, it can be beneficial to operate the LCL tuned circuit 201 with a unity power factor. That is, the voltage and current seen from the inverter 6 across or through the first leg 210 and the second leg 211 are in-phase. Maintaining the power factor at or close to unity is desirable because it means that the current through the series tuning inductor 209 is minimised, which helps to reduce power losses on this inductor. Furthermore, the inverter 6 is able to use zero current switching for SI 202, S2 203, S3 204 and S4 205 which helps to reduce switching losses.
  • a unity power factor helps minimize the amount of VARs that the inverter 6 needs to provide or absorb, since the amount of reactive power provided by the inverter 6 into the LCL tuned circuit 201 is minimized. These factors help to improve the efficiency of the inverter 6 and the LCL tuned circuit 201, while minimizing the size, the voltage ratings and the current ratings of their constituent components.
  • the value of the load 11 the coupling coefficient between the transmitting coil or coils 7 and the power pick up stage 9 and the introduction of foreign metallic objects can all affect the power factor of the LCL tuned circuit 201. Also the inductance of the transmitter coil 7 will change under different conditions.
  • a possible solution to achieving the desired power factor for the LCL tuned circuit 201 in spite of component variation and system changes is to adjust the values of the reactive components in the LCL tuned circuit 201 during operation of the IPT system 1. For example, additional inductance or capacitance can be switched into or out of the LCL tuned circuit 201 so that it operates with unity power factor.
  • the use of saturable inductors can also allow the LCL tuned circuit 201 to be re-tuned during use.
  • the drawback of these solutions is that they add additional cost, complexity and bulk to the inductive power transmitter 2.
  • the LCL tuned circuit 201 may also not always desirable to operate the LCL tuned circuit 201 at unity power factor. It also may be desirable to change the operating power factor during operation. In some cases it may be desirable to run the LCL tuned circuit 201 at a lagging power factor as shown in Figure 5. For example, by running the LCL tuned circuit 201 at a lagging power factor, zero voltage switching (ZVS) in the full bridge can be achieved. Soft switching is important in order to both reducing the power loss in the switches SI 202, S2 203, S3 204 and S4 205 and in reducing the high frequency electromagnetic noise that would introduced by hard switching.
  • ZVS zero voltage switching
  • the body diodes 214 in the full bridge inverter 6 can be made to conduct before the switches SI 202, S2 203, S3 204 and S4 205 are turned on which prevents the overlap of high current and voltage in the switches. This reduces switching losses. Switching losses can be approximately halved when ZVS is used compared with when no ZVS is used. ZVS will only occur under specific conditions for the circuit topology shown in Figure 2, ZVS can be obtained by controlling the power factor of the LCL to be slightly lagging.
  • zero voltage switching can occur when D ⁇ 0.5.
  • switch S2 and S3 were conducting.
  • S2 and S3 are turned off and a gate pulse is applied to SI and S4 . Since iL is negative at this instant, it flows through Dl and D4 .
  • Dl and D4 turn off naturally at zero current and iL now flows through SI and S4 .
  • the device conduction sequence is such that the antiparallel diodes conduct prior to the switch conduction resulting in ZVS turn- on for both the switches.
  • the controller 8 will typically be able to determine the driving voltage 212 from the combination of the gate drive signals it creates as well as the value of the voltage coming from the DC source 206. However the phase and magnitude of the driving current 213 may be unknown to the controller 8 and this information is useful in measuring the power factor of the LCL tuned circuit 201.
  • a current transformer can be used for current detection, placed for example in series with the series tuning inductor 209.
  • the inverter 6 and the LCL tuned circuit 201 can also be run with so that the LCL tuned circuit 201 has a leading power factor as shown in figure 7. While a slightly lagging power factor can be used to achieve maximum efficiency, higher power can be obtained when operating at a leading power factor and a higher frequency.
  • An increase in frequency will act to decrease the overall impedance seen by the inverter 6 looking into the LCL tuned circuit 201 and increase the current in the transmitting coil or coils 7, thus providing a higher potential maximum output power. For example, in one test it was observed that at an operating frequency of 200kHz the current flowing in the transmitting coil 7 was 5.02A while at 210kHz the current flowing was 5.52A.
  • this method may be used to provide a temporary power boost (or allow the system to operate at a lower k) for a short period of time.
  • the ideal power factor or phase difference varies depending on the distance between the transmitting coil or coils 7 and the power pick up stage 9. For example, in one test, at 15mm separation a leading power factor is ideal in order to allow enough power transfer to the receiver. At smaller separations, a unity or lagging power factor may be more efficient.
  • Figures 8a and 8b show the changes to the effective inductances of the transmitting coil or coils 7 and a receiving coil or coils 801 that occur when the distance between the transmitting coil or coils 7 and the receiving coil or coils 801 is changed, or alternately when the coupling coefficient is changed.
  • an LCL tuned circuit is used for both the inductive power transmitter 2 and the inductive power receiver 3, which also includes a series tuning capacitor 802, a parallel tuning capacitor 803 and a series tuning inductor 804.
  • the values shown are for coupling coefficient changing from 0.26( Figure 8a) to 0.5( Figure 8b).
  • the reactance of each branch is matched, the LCL is correctly tuned and will operate at unity power factor.
  • the LCL tuned circuit becomes detuned when the coupling between the transmitting coil or coils 7 and the receiving coil or coils 801 is high. This causes large currents to flow through the series tuning inductor 209 of the inductive power transmitter 2 as well as the equivalent component which may be present in the inductive power receiver 3. This can cause damage to the IPT system 1 and can result in low efficiencies. Sometimes this effect can even be present in the case of moderate coupling coefficients between the transmitting coil or coils 7 and the receiving coil or coils 801.
  • the frequency response of the system changes with changing coupling and changing load. Also, the load reflected by the receiver is not constant and is likely to be non-linear given how the shorting control regulates the Tx output voltage.
  • the frequency response of the current in the Tx LCL changes with changing coupling between 0.3 in Figures 9a and 0.6 in Figure 9b.
  • the frequency 902 where unity power factor can be achieved decreases with increased coupling eg: 200kHz @ 0.3 and 190kHz @ 0.6. It may be desirable to control the power factor to be slightly lagging under all conditions of load and coupling. This achieves zero voltage switching as well as keeping the reactive power provided by the supply to a minimum.
  • the controller 8 can derive the phase of the driving voltage 212 because the controller 8 produces the gate drive signals controlling the inverter 6.
  • the controller can obtain the phase of the driving current 213 by using a current transformer placed in series with the series tuning inductor 209 and comparing the secondary side output of the current transformer to ground with a fast comparator for example. By then making changes to the switching frequency the controller can maintain a constant phase angle or power factor angle between the driving voltage 212 and the driving current 213.
  • a control strategy for the circuit shown in Figure 2 is shown in Figure 10.
  • the controller simply controls the frequency up or down to achieve a desired power factor or phase between the voltage and current.
  • Figure 11 shows an alternative controller 8 that controls the power transfer as well as the power factor.
  • the transmitter is independent in that it does not need to communicate directly with the inductive power receiver 3.
  • the controller 8 is able to control the duty cycle based on measured values within the inductive power transmitter 2. For example, as the input voltage varies from 21.6V to 26.4V the duty cycle can be decreased linearly from 50% to 35%.
  • the controller 8 may control the frequency to maintain a given power factor such as a certain lagging power factor for the LCL tuned circuit 201.
  • the controller 8 can estimate the approximate separation between the transmitting coil or coils 7 and the receiving coil or coils 801 from the frequency that is required to maintain the specific power factor. If the operating frequency is low, it means the inductive power receiver 3 is closer and so the duty cycle can be reduced. For example the maximum duty cycle at 200kHz (at 21.6V) could be 50% while the maximum duty cycle at 180kHz could be 35%. The opposite applies if the operating frequency increases.
  • the duty cycle of the inverter 6 can be chosen by estimating the load 11 by monitoring the input power from the power supply 4 or through the converter 5. For example, for an input power of HOW the duty cycle can be set to the 50% for maximum output power while when the input power is 30W the duty cycle can be set to 30% for reduced output power. Under some circumstances the inductive power receiver 3 may fall out of regulation due to insufficient received power but the input power to the inductive power transmitter 2 may remain be quite high.
  • Figure 12 shows a further alternative controller 8 wherein the receiver communicates information about output voltage, for example, the quality of the regulation and/or the receiver series tuning inductor current. Having information from the receiver would allow better control including duty cycle control and more versatile frequency control. The Transmitter then adjusts frequency and duty cycle to provide the most efficient operating point.
  • the receiver communicates information about output voltage, for example, the quality of the regulation and/or the receiver series tuning inductor current. Having information from the receiver would allow better control including duty cycle control and more versatile frequency control. The Transmitter then adjusts frequency and duty cycle to provide the most efficient operating point.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

Émetteur de puissance inductive comprenant un circuit LCL qui comprend une bobine émettrice; et un inverseur de puissance comprenant une pluralité de dispositifs de commande conçus pour entraîner le circuit LCL; la fréquence d'une pluralité de signaux de commande pour les dispositifs de commande respectifs étant déterminée sur la base d'un facteur de puissance souhaité pour le circuit LCL.
PCT/NZ2017/050007 2016-01-29 2017-01-26 Émetteur de puissance inductive WO2017131532A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201662288637P 2016-01-29 2016-01-29
US62/288,637 2016-01-29

Publications (1)

Publication Number Publication Date
WO2017131532A1 true WO2017131532A1 (fr) 2017-08-03

Family

ID=59398611

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NZ2017/050007 WO2017131532A1 (fr) 2016-01-29 2017-01-26 Émetteur de puissance inductive

Country Status (1)

Country Link
WO (1) WO2017131532A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019213341A (ja) * 2018-06-05 2019-12-12 トヨタ自動車株式会社 非接触送電装置及び非接触電力伝送システム

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013112614A1 (fr) * 2012-01-23 2013-08-01 Utah State University Système de transfert de puissance sans fil
US20150061577A1 (en) * 2013-09-04 2015-03-05 Freescale Semiconductor, Inc. Wireless power transmitters with wide input voltage range and methods of their operation

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013112614A1 (fr) * 2012-01-23 2013-08-01 Utah State University Système de transfert de puissance sans fil
US20150061577A1 (en) * 2013-09-04 2015-03-05 Freescale Semiconductor, Inc. Wireless power transmitters with wide input voltage range and methods of their operation

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHWEI-SEN WANG ET AL.: "Investigating an LCL Load Resonant Inverter for Inductive Power Transfer Applications", IEEE TRANSACTIONS ON POWER ELECTRONICS, vol. 19, no. 4, July 2004 (2004-07-01), pages 995 - 1002, XP011114979, DOI: doi:10.1109/TPEL.2004.830098 *
NICHOLAS A. KEELING ET AL.: "A Unity- Power -Factor IPT Pickup for High- Power Applications", IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol. 57, no. 2, February 2010 (2010-02-01), pages 744 - 751, XP011294713 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019213341A (ja) * 2018-06-05 2019-12-12 トヨタ自動車株式会社 非接触送電装置及び非接触電力伝送システム
JP7119598B2 (ja) 2018-06-05 2022-08-17 トヨタ自動車株式会社 非接触送電装置及び非接触電力伝送システム

Similar Documents

Publication Publication Date Title
JP6830890B2 (ja) 誘導電力受信機
Colak et al. A novel phase-shift control of semibridgeless active rectifier for wireless power transfer
US9755534B2 (en) High efficiency high frequency resonant power conversion
KR102209812B1 (ko) 무선 전력 전송 장치
CN104953683B (zh) 感应功率传递系统以及用于操作感应功率传递系统的方法
US9287790B2 (en) Electric power converter
EP3097636B1 (fr) Appareil électronique et procédé de commande pour la conversion ca-cc à haute fréquence
EP2684286A2 (fr) Procédé et appareil permettant de commander des convertisseurs lcl à l'aide de techniques d'annulation de tension asymétrique
US7821801B2 (en) Power factor correction method for AC/DC converters and corresponding converter
CN101247090A (zh) 多相直流-直流变换器
WO2015126946A1 (fr) Topologie d'onduleur résonant, chargeur sans fil, et procédé de régulation
US20180269726A1 (en) Inductive Power Transmitter
Asa et al. A novel phase control of semi bridgeless active rectifier for wireless power transfer applications
CN110957796B (zh) 无线充电电路和系统
Wang et al. A primary-sided CLC compensated wireless power transfer system based on the class D amplifier
Yang et al. A hybrid load matching method for WPT systems to maintain high efficiency over wide load range
US11569757B2 (en) System for transferring electrical power to an electrical load
WO2017131532A1 (fr) Émetteur de puissance inductive
EP3669438B1 (fr) Système de transfert d'énergie électrique sans contact et son procédé de fonctionnement
WO2017105256A1 (fr) Récepteur de puissance inductive
Matsuura et al. Multiple-transmitter achieving load-independent transmitter current and compensation of cross-interference among transmitters for wide charging area wireless power transfer systems
Song et al. Class E active rectifier with controlled output voltage for MHz wireless power transfer
WO2016148580A1 (fr) Récepteur de puissance inductif
Ahmad et al. Multi-cell Operation of Class-PN at 6.78 MHz using GaN Devices for Industrial Dielectric Heating
JP2017005841A (ja) 送電機器

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17744630

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17744630

Country of ref document: EP

Kind code of ref document: A1