Wireless power transmission system
Abstract
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Term
2.5 yearsto projected expiry
Projected expiry 31 March 2029, counted from filing; an application has no term until it is granted.
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12 claims: 8 independent, 4 dependent
- 1Zastrzeżenia 1. Bezprzewodowy system transmisji energii, zawierający - jednostkę bazową (1) z wieloma obwodami generatora pola magnetycznego, wspomniane obwody generatora są rozmieszczone na płaszczyźnie, tworząc obszar transmisji, w którym - wspomniana jednostka bazowa (1) zawiera sterownik (3), skonfigurowany tak aby wyznaczyć obwód transmisyjny (2’) spośród wspomnianych obwodów generatora, w celu transferu energii do urządzenia (10) kiedy induktor odbiorczy wspomnianego urządzenia (10) jest w pobliżu wspomnianego obwodu transmisyjnego (2’), po czym wspomniany obwód transmisyjny (2’) pracuje generując pierwsze pole magnetyczne (8) posiadające pierwszą fazę, tak aby wzbudzić prąd we wspomnianym induktorze odbiorczym, znamienny tym, że wspomniany sterownik (3) jest ponadto skonfigurowany tak aby obsługiwać przynajmniej jeden z pozostałych obwodów generatora jako obwód kompensacyjny (2”, 52, 82), który ma generować drugie pole magnetyczne (21), posiadające fazę przeciwną do wspomnianej pierwszej fazy, wspomniany obwód kompensacyjny (2”, 52, 82) zawiera co najmniej jeden zwój z przewodnika, umieszczony na brzegu wspomnianego obszaru transmisji w celu generowania wspomnianego drugiego pola magnetycznego (21).
- 2Bezprzewodowy system transmisji energii, zawierający - jednostkę bazową (1) z wieloma obwodami generatora pola magnetycznego, w której - wspomniana jednostka bazowa (1) zawiera sterownik (3), skonfigurowany tak aby wyznaczyć obwód transmisyjny (2’) spośród wspomnianych obwodów generatora, w celu transferu energii do urządzenia (10) kiedy induktor odbiorczy wspomnianego urządzenia (10) jest w pobliżu wspomnianego obwodu transmisyjnego (2’), po czym wspomniany obwód transmisyjny (2’) pracuje generując pierwsze pole magnetyczne (8) posiadające pierwszą fazę, tak aby wzbudzić prąd we wspomnianym induktorze odbiorczym, znamienny tym, że - wspomniany sterownik (3) jest ponadto skonfigurowany tak aby wyznaczyć co najmniej jeden obwód kompensacyjny (2”, 52, 82) spośród jednego z pozostałych obwodów generatora, tak aby wspomniany obwód transmisyjny (2’) i wspomniany obwód kompensacyjny (2”, 52, 82) sąsiadowały ze sobą oraz - wspomniany sterownik (3) jest skonfigurowany tak aby obsługiwać przynajmniej jeden z obwodów kompensacyjnych (2”, 52, 82), żeby generować drugie pole magnetyczne (21), posiadające fazę przeciwną do wspomnianej pierwszej fazy.
- 3System według zastrzeżenia 1 lub 2, w którym wspomniany obwód transmisyjny (2’) i wspomniany co najmniej jeden obwód kompensacyjny (2”, 52, 82) działają tak, że amplituda strumienia magnetycznego wspomnianego pierwszego obwodu magnetycznego (8) odpowiada amplitudzie strumienia magnetycznego wspomnianego drugiego pola magnetycznego (21).
- 4System według któregokolwiek z powyższych zastrzeżeń, w którym każdy ze wspomnianych obwodów generatora zawiera cewkę (2) z wieloma zwojami do generacji wspomnianych pól magnetycznych (8, 21).
- 5System według zastrzeżenia 4, w którym liczba zwojów w obwodzie transmisyjnym (2’) odpowiada liczbie zwojów co najmniej jednego obwodu kompensacyjnego (2”, 52, 82).
- 6System według któregokolwiek z powyższych zastrzeżeń, w którym każdy obwód generatora posiada powiązany z nim detektor (4), połączony ze sterownikiem (3), w celu wykrycia bliskości induktora odbiorczego w stosunku do odpowiedniego obwodu generatora.
- 7System według zastrzeżenia 6, w którym wspomniane detektory (4) są detektorami RFID, a wspomniane urządzenie zawiera etykietę RFID (17).
- 8System któregokolwiek z powyższych zastrzeżeń, w którym wspomniana jednostka bazowa (1) zawiera czujnik, połączony ze sterownikiem (3) do wykrywania pola magnetycznego, tak że wspomniany obwód kompensacyjny (2”, 52, 82) pracuje tak aby minimalizować dalekie pole magnetyczne wspomnianego obwodu transmisyjnego (2’).
- 9System według któregokolwiek z powyższych zastrzeżeń, dodatkowo zawierający urządzenie (10), możliwe do oddzielenia od wspomnianej jednostki bazowej (1) i posiadające induktor odbiorczy, dostosowany do indukcyjnego odbioru energii kiedy wspomniane urządzenie (10) jest w pobliżu jednego ze wspomnianych obwodów generatora.
- 10Sposób działania bezprzewodowego systemu transmisji energii, składającego się z jednostki bazowej (1), posiadającej wiele obwodów generatora pola magnetycznego i urządzenia (10), oddzielnego od wspomnianej jednostki bazowej (1), posiadającego induktor odbiorczy dostosowany do indukcyjnego odbioru energii kiedy wspomniane urządzenie (10) jest w pobliżu jednego ze wspomnianych obwodów generatora, wspomniane obwody generatora są rozmieszczone na płaszczyźnie, tworząc obszar transmisji, w którym - ustalana jest bliskość induktora odbiorczego i obwodu transmisyjnego (2’) spośród wspomnianych obwodów generatora, - wspomniany obwód transmisyjny (2’) pracuje wytwarzając pierwsze pole magnetyczne (8) aby wzbudzić prąd we wspomnianym induktorze odbiorczym, znamienny tym, że - co najmniej jeden z pozostałych obwodów generatora pracuje jako obwód kompensacyjny (2”, 52, 82) generując drugie pole magnetyczne (21) o fazie przeciwnej do wspomnianego pierwszego pola magnetycznego (8), - wspomniany obwód kompensacyjny (2”, 52, 82) zawiera co najmniej jeden zwój przewodnika, umieszczony na brzegu wspomnianego obszaru transmisji w celu generacji wspomnianego drugiego pola magnetycznego (21).
- 11Sposób działania bezprzewodowego systemu transmisji energii, składającego się z jednostki bazowej (1), posiadającej wiele obwodów generatora pola magnetycznego i urządzenia (10), oddzielnego od wspomnianej jednostki bazowej (1), posiadającego induktor odbiorczy dostosowany do indukcyjnego odbioru energii kiedy wspomniane urządzenie (10) jest w pobliżu jednego ze wspomnianych obwodów generatora, w którym - ustalana jest bliskość induktora odbiorczego i obwodu transmisyjnego (2’) spośród wspomnianych obwodów generatora, - wspomniany obwód transmisyjny (2’) pracuje wytwarzając pierwsze pole magnetyczne (8) aby wzbudzić prąd we wspomnianym induktorze odbiorczym, znamienny tym, że - wyznaczony jest co najmniej jeden obwód kompensacyjny (2”, 52, 82) spośród jednego z pozostałych obwodów generatora, tak że wspomniany obwód transmisyjny (2’) i wspomniany obwód kompensacyjny (2”, 52, 82) sąsiadują ze sobą oraz - wspomniany obwód kompensacyjny (2”, 52, 82) pracuje w celu generacji drugiego pola magnetycznego (21) w fazie przeciwnej do wspomnianego pierwszego pola magnetycznego (8).
- 12Program komputerowy umożliwiający zrealizowanie metody według zastrzeżenia 10 lub 11 po uruchomieniu na komputerze. EP 2 263 296 Β1 d UL EP 2 263 296 Β1 ro ΓΜ u LL ιη m ΕΡ 2 263 296 Β1 -Ο Γ\Ι ω LL η ιη ER 2 263 296 Β1 U ΓΜ u LL ιλ n EP 2 263 296 Β1 FIG. 3b EP 2 263 296 Β1 to sr d LL EP 2 263 296 Β1 FIG. 4c EP 2 263 296 Β1 in m FIG. 5 EP 2 263 296 Β1 ru Ο Ó UL FIG. 6b EP 2 263 296 Β1 ίϋ Γχ d UL FIG. 7b EP 2 263 296 Β1 • · FIG. 8b
Independent claims12
92 paragraphs, as filed
[0001] This invention relates to a wireless energy transmission system and its operation BACKGROUND OF THE INVENTION [0002] Electronic devices that are "mobile" or portable are used today in various commercial or personal applications. Examples of such applications include cell phones, notebooks, PDAs or portable music players. The devices listed above are usually powered by a rechargeable battery, which must be charged periodically for the device to work. In order to charge or provide external power, usually each device has a dedicated power supply that must be connected to the device and to the wall outlet. Since most devices are not compatible with each other, a dedicated power supply is needed for each device.
[0003] As the total number of such devices used increases, wireless power systems have been developed that reduce time and effort in the charging process. US 2007 / 0182367A1 describes such a wireless power source and charging system. It is a base unit that has space to accommodate one or more charging devices. Below the surface there is a series of inductor coils that generate a magnetic field that induces current in the appropriate coil of each mobile device. By using this current, you can easily charge the battery in a mobile device and without connecting the usual power supply to each of the devices to be charged.
[0004] Although the known system allows such devices to be charged wirelessly, the inductor coils in the base unit generate a rather large magnetic field of dispersion, which causes problems in electromagnetic compatibility (EMC) sensitive environments and can cause unwanted interference with subsequent electronic devices.
[0005] Document US 2001/0000960 A1 describes systems and methods for wirelessly transferring power to RFID labels. In the related arrangement, a plurality of phase-matching current loops are arranged on the surface, such that there is a "virtual current loop" on the periphery of the corresponding phase-oriented current. Current in adjacent parts of adjacent current loops flows in opposite directions. This document describes that, thanks to this arrangement, the distant field can be reduced, and thus satisfactory power for RFID tags can be obtained, reducing the risk of violating legal restrictions.
[0006] The object of this invention is to provide a wireless energy transmission system and method for operating such a system in which the magnetic field of diffusion is reduced.
SUMMARY OF THE INVENTION [0007] The object is achieved according to the invention by a wireless energy transmission system according to claims 1 and 2 and a method of operating a wireless energy transmission system according to claims 10 and 11. The dependent claims relate to preferred embodiments of the invention.
[0008] The basic idea of the invention is to provide a wireless electricity transmission system that allows energy to be transferred to the device using induction generated by a magnetic field, where the magnetic field is concentrated in a region near the device, i.e. in the near magnetic field while the far field is suppressed by a second magnetic field, which preferably reduces the magnetic field of dispersion and thereby increases the electromagnetic compatibility (EMC) of the system.
[0009] A wireless energy transmission system consists of a base unit with multiple magnetic field generator circuits and preferably at least one device, separated from said base unit and having a receiving inductor adapted for induction energy reception when said device is near one of said circuits generator.
[0010] For energy transfer, at least one of the magnetic field generator circuits, hereinafter referred to as the transmission circuit, is used to create a magnetic field that induces current in the receiving inductor of the device. To achieve efficient energy transfer, the device and therefore the receiving inductor must be physically close to the transmission circuit, i.e. in the area near the magnetic field of the transmission circuit. If the generator circuits are loops or turns of a conductor, the distance between the receiving inductor and the transmission circuit should preferably be in the range up to% of the diameter of the loop or coil.
[0011] The base unit further includes a controller configured to determine a transmission circuit from said generator circuits when said receiving inductor is near said transmission circuit. Therefore, the controller individually determines whether the device with the receiving inductor is or is not close to one of the generator circuits, so that wireless energy transmission is needed.
[0012] The controller may be of any type suitable for controlling the base unit, such as a microcontroller or a computer. It is preferred that the controller be an integral part of the base unit, although it is possible that the controller is an external unit, such as a separate computer, connected to the base unit by wires or wirelessly.
[0013] The transmission circuit is therefore operated to generate a first magnetic field having a first phase, i.e. a first magnetic field having a magnetic flux in the first phase, to induce current in said receiving inductor. This current can then be used in the device, for example, to power the electrical or electronic components of the device or to charge the battery.
[0014] At least one of the remaining generator circuits works as a compensating circuit to generate a second magnetic field opposite the said first phase, i.e. a second magnetic field having a second magnetic flux opposite the said first phase. In the context of the present invention, the term "opposite phase" means a phase difference of 180 ° from said first phase. Because of the opposite phase, the magnetic fluxes of the first and second magnetic fields are always in the opposite direction. The second magnetic field is therefore used to compensate for the first magnetic field in the far magnetic field, which advantageously reduces the field of dispersion emitted by the system, while allowing efficient power transfer to the device in the near field.
[0015] In addition to the far-field compensation effect, the operation of at least one of the generator circuits as a compensating circuit to obtain a second magnetic field in the phase opposite to said first magnetic field may increase the amplitude of the magnetic flux of the transmission circuit in the near field, and thus further improve inductive energy transfer to the device. This effect is particularly great when the compensation circuits are arranged close to or adjacent to the respective transmission circuits.
[0016] Two general systems for the wireless energy transmission system of the invention are possible.
[0017] According to a first aspect of the invention, the generator circuits are arranged in a plane forming a transmission area. This system allows efficient production of the base unit and thus the energy transmission system. In addition, this arrangement allows the creation of a flat surface to accommodate one or more devices.
[0018] For the effective abolition of a far magnetic field, said compensation system in accordance with the present aspect of the invention comprises at least one conductor coil located at the periphery of said transmission area to generate said second magnetic field.
[0019] Preferably, at least one conductor coil is in the shape of a substantially closed loop that surrounds the transmission area, i.e. the area in which the transmission circuit and other generator circuits are arranged. This system allows the effective removal of a distant magnetic field while maintaining a sufficiently close magnetic field to transmit energy to the device. Of course, such a compensating circuit may contain more than one conductor turn, and ideally it contains many conductor turns with intermediate taps, so that the number of working turns of the conductor can be changed, thus allowing the magnetic flux of said second magnetic field to be changed without any change in the arrangement. Such a construction can be useful, for example, when the number of working transmission circuits changes and thus the total magnetic flux of the transmission circuits to be compensated changes accordingly.
[0020] According to a second aspect of this invention, the controller may be configured to determine at least one compensation circuit among said multiple generator circuits, such that said transmission circuit and said compensation circuit are adjacent. In the context of the present invention, the term "adjacent" means that the transmission circuit and the compensation circuit are directly adjacent, without a further generator circuit between them. Also in this system the far magnetic field is effectively reduced. In addition, as previously mentioned, the present embodiment further advantageously increases energy transfer to the device.
[0021] Naturally, the controller may be configured to define more than one compensation circuit adjacent to the transmission circuit in such a way that said plurality of compensation circuits surround at least partly the transmission circuit.
[0022] It is preferred that the adjacent generator circuits overlap. It is most desirable for the field generator circuits to be distributed in many layers. For example, there may be a first layer in which the transmission system is located and there should be at least a second layer in which there is at least one compensation circuit. In addition to this, it is preferred that the transmission circuits and / or compensation circuits are arranged such that at least partially overlap in a direction perpendicular to the first and / or second layer.
[0023] Of course, more than one transmission circuit can operate simultaneously when more than one device is near the respective transmission circuit so as to carry out parallel transmission of energy to different devices. In this case, the compensation circuit operates in such a way that the phase of the second magnetic field is opposite to the phase of the sum of the magnetic fields of said multiple transmission circuits.
[0024] In addition, more than one of the generator circuits may act as compensation circuits to increase the efficiency of compensation. It is beneficial that the other generator circuits of this system, which do not work as a transmission or compensation circuit, serve to generate only weak magnetic fields in order to further reduce the scattering field of the system. It is most recommended that the other generator circuits be turned off.
[0025] As mentioned above, the second magnetic field has a phase opposite to said first phase to lift the magnetic field in the distant zone. Any method known in the art can be used to obtain said opposite phase magnetic field. Preferably, the compensation circuit is operated with an electric signal that corresponds to the signal for the transmission circuit, but is in the opposite phase to that signal, i.e. is 180 ° out of phase.
[0026] The basic unit may comprise further elements, such as successive control circuits or one or more signal generators, connected to the field generator circuits, so as to provide the circuits of this field generator with electric current to generate appropriate magnetic fields.
[0027] In order to eliminate fields in the far magnetic field more effectively, it is best to use a transmission circuit and at least one compensation circuit, so that the magnetic flux amplitude of the first magnetic field, depending on the flux density and the area of the transmission circuit area, corresponds to the amplitude of the magnetic flux magnetic field, depending on the flux density and the area of the compensation circuit. In this case, the sum of the moments of the magnetic dipoles of the said magnetic fields - the first and second - cancel each other out in a distant magnetic field with greater efficiency. In the case where the transmission circuit and at least one compensation circuit are coils, it is best that the magnetic flux of the first magnetic field corresponds to the magnetic flux of the second magnetic field, depending on the density of the flux and the cross-sectional area of the respective coils.
[0028] In the context of the present invention, the term "corresponds" to a magnetic flux is understood to include equal magnetic flux amplitudes of said first and second magnetic fields, but also includes deviations of +/- 50%, better +/- 20 %, preferably +/- 10% and +/- 5%. The choice of magnetic flux from the above ranges still gives a reasonable reduction of the far magnetic field.
[0029] When more than one transmission circuit or more than one compensation circuit is operated, the transmission circuits and compensation circuits operate such that the magnetic flux of the first magnetic field, i.e. the amplitude of the magnetic flux generated by all transmission circuits, preferably corresponds to the amplitude of the magnetic flux second magnetic field, i.e. the sum of the magnetic flux generated by all compensation circuits. As previously mentioned, the magnetic flux of said first magnetic field corresponds to the magnetic flux of said second magnetic fields, depending on the density of the flux, and the surface of the transmission and compensation circuits, respectively.
[0030] The magnetic field generator circuits may be of any type suitable to efficiently generate a magnetic field; e.g. ordinary conductor loop or one or more turns of such a conductor. It is best if each of the mentioned generator circuits contains a coil with many turns to generate a magnetic field. By using a coil it is possible to efficiently generate said magnetic field in order to obtain the appropriate field strength for efficient energy transmission to the device. According to an embodiment of the invention, the coils are located on a printed circuit board (PCB) in one or more layers of said PCB. It is best if the coils are flat coils, i.e. they are in one layer of a PCB, which allows cost-effective production.
[0031] The receiving inductor can be any type of conductor that can receive energy inductively, such as, for example, a simple wire loop or circuit on a printed circuit board. Preferably the receiving inductor should be a coil.
[0032] As mentioned above, system performance is further advantageously increased when the magnetic flux amplitude of the second magnetic field is close to or equal to the magnetic flux amplitude of the first magnetic field. Therefore, it is recommended that the voltage used in the transmission circuit correspond to the voltage used in the compensation circuit. In addition or as an alternative to this and in the event that each of the mentioned generator circuits contains a coil with many turns, it is best if the number of turns in the transmission circuit corresponds to the number of turns in the compensation circuit. If more than one transmission circuit or more than one compensation circuit is working, it is best if the total number of turns of all transmission circuits corresponds to the total number of turns of all compensation circuits.
[0033] The device can be any type of electrical or electronic device that needs electricity to operate. It is best if it is a mobile device, i.e. a mobile device or device that cannot be connected directly to the power supply network, for example in the area of medical applications. The most preferred such device is a mobile device having energy batteries connected to said receiving inductor in order to charge these energy batteries. The energy accumulators may be of any suitable type, for example rechargeable batteries or a capacitor, e.g. a "supercapacitor".
[0034] To detect that the device is close to the transmission circuit, any method known in this field can be used. For example, the controller can send weak current to each of the generator circuits and can detect the presence of the device by monitoring the status of each circuit.
[0035] According to a preferred embodiment, each generator circuit has an associated detector connected to the controller to detect that the receiving inductor is close to the corresponding generator circuit. This arrangement makes it possible to effectively determine that the device is close to the transmission circuit.
[0036] The detectors may be of any type suitable for detecting the clarity of the device, for example by means of a weight change using a pressure detector, by means of an electric or magnetic field change using a field detector, by means of ultrasonic wave or optical detection. It is best if the detector is a field detector and has a parallel resonant circuit. In this case the device has a magnetic element, e.g. a plate of soft magnetic material. When the device is close to the resonant circuit, the inductance of this resonant circuit increases. It is therefore possible to detect a change in the impedance or resonance frequency of the resonant circuit, enabling detection of the proximity of the device.
[0037] Preferably, the detectors are RFID detectors and the device includes RFID tags. The present embodiment preferably allows detecting the device and transferring additional data between the device and the base unit, e.g. device type, required current, energy transfer time or any other information enabling improvement of system performance. It is best that the information contained in the RFID labels is used by the controller to support the transmission and compensation circuits, respectively. For example, the RFID tag may contain information about the loading time, which is passed to the controller, which in turn controls the transmission and compensation circuits for this specific duration.
[0038] As mentioned earlier, the compensation circuits can operate by means of a signal that corresponds to the signal provided to the transmission circuit, but which is in the opposite phase to that signal. To achieve an effective reduction of the distant magnetic field, the total current flowing through one or better through more compensation circuits corresponds to the current flowing through one or more transmission circuits.
[0039] In an alternative embodiment, it is preferred that said base unit has a sensor connected to the controller for detecting a magnetic field, i.e. a magnetic flux. It is therefore possible to actively control one or more compensation circuits to minimize the distant magnetic field of the transmission circuit, depending on the received field. Such active control - i.e. feedback - can be obtained by changing the voltage of the compensation circuits. If the compensation circuits are coils, alternatively or in addition to voltage control, the number of conductor turns can be changed to control or set the magnetic flux of said second magnetic field. For example, the sensor can be a Hall sensor or an ordinary coil with a suitable field detection circuit.
[0040] To enable a more precise measurement of the far field and thus further increase the reduction of the far magnetic field, it is best if the sensor is located at a certain distance from the transmission circuit. For example, the sensor may be located on the periphery of said transmission area or base unit, or may even be in a separate unit connected to the base unit, but which may be placed at a certain distance from the base unit.
[0041] The above and other objects, features and advantages of the present invention will become apparent in the following description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS [0042]
Fig. 1 shows the first embodiment of the wireless energy transmission system according to the invention in a three-dimensional exploded view,
Fig.2a shows a schematic top view of the second embodiment in the working state,
Fig.2b shows a schematic top view of the embodiment of Fig.2a in a second operating condition,
Fig.2c shows a schematic top view of the embodiment of Fig.2a in the next operating state,
Fig. 3a and 3b show the circuit diagram for the embodiment of Fig. 2a,
Fig.4a shows a schematic top view of the third embodiment in working condition, Fig. 4b and 4c show a circuit diagram of the embodiment in Fig. 4a,
Fig. 5 shows the fourth embodiment of the wireless energy transmission system according to the invention in a schematic top view,
Figs. 6a and 6b show the circuit diagram for the embodiment in Fig. 5,
Fig.7a and 7b show the circuit diagram for the fifth embodiment and Fig.8a and 8b show the circuit diagram for the sixth embodiment,
DETAILED DESCRIPTION OF EMBODIMENTS According to Figure 1, the base unit 1 has a plurality of magnetic field generator circuits, i.e., flat spiral coils 2, arranged in one layer of the printed circuit of the base unit 1. Coils 2 are connected to a controller 3, which may be e.g. microcontroller. The connections (not shown) may e.g. be in the next layer of a multi-layer printed circuit or in the form of wires. The controller 3 is connected to the power supply unit 5 to provide the coils 2 with a specific AC voltage to generate alternating magnetic fields. A soft magnet plate 6 is located on the bottom side of the base unit 1 to reduce the magnetic scattering fields. Each coil 2 has a detector 4 assigned to it, e.g. an RFID detector, connected to the controller 3 and placed in the center of each coil 2 assigned to it. The detectors 4 are configured to detect the proximity of the device 10, which for illustration is shown in an unfolded state.
[0044] The device 10 comprises a receiving inductor, a flat spiral receiving coil 11, located in the layer 13 of the printed circuit. A soft magnet plate 12 is placed on top of the flat coil 11 to shield the magnetic field of the coil 2 from the rest of the device 10, as explained below. The receiver coil 11 is connected to the rectifier 14, which connects the receiver coil 11 to the battery 15. Capacitor 16 is connected in series with them to increase the efficiency of magnetic field coupling. To enable detection of the proximity of the device 10 to one of the coils 2, the device 10 includes an RFID tag 17 that is detectable by the detectors 4 when in the vicinity. RFID tag 17 also contains information about charging the device 10. Such charging information may include information about the required voltage, charging time or any other parameter that can be used by the controller 3 to improve energy transfer to the device 10.
[0045] When the device 10 is close to one of the coils 2, the detector 4 associated with the coil 2 detects the presence of the RFID tag 17 and thus the devices 10. Then the controller 3 supplies the coil 2 with an AC voltage generated by the power unit 5, so that the coil 2 acts as a 2 'transmission circuit. Thus, the transmission circuit 2 'generates the first alternating magnetic field 8, which induces a current in the receiving coil 11 for charging the battery 15. To reduce the magnetic field of diffusion, the controller 3 supplies at least one of the remaining coils 2 with an alternating phase voltage of the opposite phase, so that a second magnetic field with the opposite phase to the said first phase is generated. In this way, the distant magnetic field is effectively reduced. As can be seen in the figure, the base unit 1 is scalable and is not limited to a specific number of coils 2, which may vary depending on the application, for example, rather larger base units 1 with more coils 2 can be used when simultaneous use is needed power supply for many devices 10.
[0046] Further details of the invention are explained with reference to drawings 2a-2c, which show a schematic top view of a second embodiment of a wireless energy transmission system in a number of operating states. Because alternating fields are used to induce current in the receiving coil 11, Figs. 2a-2c show "snapshots" of the system at a given time to explain the system's operation.
[0047] According to the embodiment in Fig. 2, the base unit 1 having a 3x4 matrix of coils 2 is used for wireless energy transfer to one or more devices 10 (not shown). One of the coils 2 is operated by the controller 3 as a 2 'transmission circuit to transfer energy to a device 10 (not shown) located on the upper surface of the 2' transmission circuit. The transmission circuit 2 'is therefore powered by the controller 3 by means of the first signal in the first phase, i.e. according to the "snapshot" in Fig. 2 in the first direction indicated by arrows 7, thereby generating the first magnetic field 8 in the first phase, i.e. in the first direction.
[0048] Four coils 2 adjacent to the transmission circuit 2 'act as compensation circuits 2 ". The 2 "compensation circuits are supplied by the controller 3 with a signal corresponding to the first signal but having the opposite phase, i.e. the opposite direction at all times, as shown by arrows 9. Thus, the 2" compensation circuits generate a second magnetic field 21 having the opposite phase to the said first field magnetic 8. Thus, the first magnetic field 8 is compensated in the distant field of the field by said second magnetic field 21. In addition to the compensation effect in the far field, the arrangement of 2 "compensating circuits adjacent to the 2 'transmission circuit increases the first magnetic field 8, and thus the energy transmission to the device 10. Fig. 2b and 2c show the embodiment of Fig. 2a in subsequent operating states, where two coils 2 act as 2 'transmission circuits and a plurality of 2' compensation circuits arranged adjacent to these two 2 'transmission circuits. Therefore, it is possible to simultaneously transfer energy to more than one device 10 (not shown), located on the upper surface of the respective 2 'transmission circuit.
[0049] Fig. 3a and 3b show circuit diagrams for the embodiment of fig. 2a. As can be seen in the drawing, each coil 2 is connected to the power supply 5 via switches 31, which are controlled by the controller 3. Each coil 2 can therefore be connected to an AC supply in the positive or opposite direction. Fig. 3a shows the system in the off state, all switches 31 are open. The working condition in Fig. 3b corresponds to that in Fig. 2c. Two of the coils 2 are connected as 2 'transmission circuits to generate the first magnetic field 8, and two adjacent, i.e. adjacent, are connected in the opposite phase, i.e. according to the' snapshot 'in Fig. 3b in the opposite direction as compensation circuits 2 ”- as the arrows in Fig. 3b show - to compensate for the far magnetic field of the first magnetic field 8. The switches 31 are set so as to connect in opposite directions the corresponding coils 2 to the power supply 5.
[0050] To improve the compensation of the first magnetic field 8 in the far zone, the sum of the magnetic flux of the second magnetic field generated by the 2 "compensation circuits, below marked as Φς should have the same amplitude all the time but the opposite direction to the magnetic flux generated by the transmission circuits 2 'energy marked as Φτ *:
Φ<sub>Τχ</sub><sup>=</sup> -C (1) [0051] Generally, the magnetic flux Φ generated by the coil 2 depends on the voltage U supplied to the coil 2:
υ = (2) where N = the number of turns of the coil 2. The diameter of the coil 2 does not matter.
(0052] For sinusoidal flux and voltage, this equation can be expressed as a function of frequency f using imaginary numbers:
U = j-2nf'N- <P (3) [0053] For a system with two coils 2, with one transmission circuit 2 'and one compensation circuit 2 ", operating with the same frequency f, the condition of abolishing the far field can be easily express as:
(4) 'Γχ <sup>N</sup>C
Where index Tx refers to the 2 'transmission circuit and index C refers to the 2 "compensation circuit. If there are any number of active 2 'transmission circuits (η<sub>Τχ</sub>) and the number of compensation circuits 2 "(n<sub>c</sub>), the sum of all components of the magnetic flux from the 2 'transmission circuits should be equal to the sum of the streams of all 2' compensation circuits. What was expressed in the form of an equation:
(5)
Σ<sup>η</sup>Τχ \ ~ ^<sup>n</sup>C <sup>φ</sup>τχ (Ο = / -<sup>φ</sup>ϋ W 1 = 1 4-J / c = 1 [0054] If the coils 2 are not very well coupled in the near field, equation (4) is used, and the principle for technical implementation can be expressed as:
Υ "" M <sub>=</sub> Y "<sup>c</sup> ,<sub>6)</sub>
2 -, (= 1 »τ« ω 2 -. ,,, 1 "cm <sup>v</sup>'[0055] When identical coils 2 with a corresponding number of turns are used for energy transmission, i.e. as transmission circuits 2' and for field compensation, i.e. as compensation circuits 2 ', a simple control method is to connect the same number of coils 2 turned on for energy transmission as turned on in compensating circuits, but in the opposite direction as shown in fig. 2c and 3b.
[0056] To further increase the effectiveness of the compensation, it is possible to add a separate controllable compensation power supply 45, as shown in Figs. 4a-4c.
[0057] Fig. 4a shows a schematic top view of a third embodiment in a working state. The basic arrangement of the energy transmission system according to the embodiment in Fig. 4a corresponds to the embodiment in Fig. 2a, in particular the arrangement of coils 2.
[0058] Each coil 2 can be connected to either a power supply 5 that supplies the transmission coils 2 'with AC voltage for energy transmission (Ugen) or with a controllable power supply 45 to provide a compensating AC voltage (Uc) for 2 "compensation circuits , using switches 31, as can be seen in Fig. 4b, which shows the circuit diagram for the embodiment according to Picture 4a. Controller 3 sets the compensation voltage according to equation (6), depending on the number of activated 2 'transmission circuits and 2' compensation circuits and their properties, as mentioned above.
[0059] Figure 4 shows a "snapshot" of the third embodiment in the operating state according to Fig. 4a, where some of the coils are activated. Only one 2 'transmission circuit is activated, but two adjacent coils are connected to the compensating AC voltage as compensating circuits 2 ". In this example, all coils 2 have the same properties, i.e. the number of turns, so controller 3 sets the absolute value of the compensation voltage Uc = '/> Ugen.
[0060] An alternative to using the coils 2 as 2 'transmission circuits or 2' compensation circuits is to use a dedicated compensation circuit 52 as shown in Fig. 5.
[0061] Fig. 5 shows a fourth embodiment of a wireless energy transmission system according to the invention, in a schematic top view in the operating state. In contrast to the embodiment in Fig. 2a, a dedicated compensation circuit 52 is located on the periphery of the base unit 1, forming the transmission area in which the coils 2 are arranged. Compensation circuit 52 forms a coil with multiple turns to generate a second magnetic field 21, which provides compensation in the distant magnetic field for the first magnetic field 8, generated by one or more 2 'transmission circuits. Compensation circuit 52 has the same number of turns as each of the coils 2. Coils 2 and compensation circuit 52 are supplied with AC voltage through power supply 5.
[0062] Figs. 6a and 6b show a circuit diagram for the embodiment of Fig. 5. Each coil 2 can be connected to the AC supply supplied by the power supply 5. The compensation circuit 52 is connected to the same power supply 5, but in the opposite direction. The controller 3 directs the switches 31 to activate the coil 2 as the 2 'transmission circuit when the device 10 (not shown) is near the corresponding coil 2. While fig. 6 shows the system in the off state, fig. 6b shows "snapshot" according to fig. 5, where one 2 'transmission circuit and compensation circuit 52 are activated. Arrows indicate the direction of the applied voltage. To compensate for the far magnetic field, the AC voltage used in the compensation circuit 52 is in the opposite phase to the AC voltage used in the 2 'transmission circuit, i.e. in the opposite direction according to the "snapshot" in Fig. 6b, as indicated by the arrows in the drawing.
[0063] Alternatively, to further increase the effectiveness of the compensation, it is possible to use a separate controllable compensation power supply 75, as shown in Figs. 7a and 7b, which show a circuit diagram of a fifth embodiment of the invention. The basic arrangement of the energy transmission system in accordance with the embodiment in Fig. 7a and 7b corresponds to the embodiment in Fig. 5, in particular the arrangement of coils 2 and compensation circuit 52.
[0064] The controller 3 controls the compensating power supply 75. The controller 3 sets the AC compensation voltage according to equation (6), depending on the number of activated transmission circuits 2 'and the properties of the compensation circuit 52. Figure 7b shows the "snapshot" of the embodiment of Fig. 7a in the operating state where two 2 'transmission circuits are activated. If compensation circuit 52 has the same number of turns, the absolute value of the compensation voltage (Uc) must be Uc = 2 x Ugen (voltage supplied to the 2 'transmission circuit), as indicated by the arrows in the drawing. The advantage of this solution is that the compensation circuit 52 may have a different number of turns than the coils 2, and thus it is more flexible.
[0065] Figs. 8a and 8b show a circuit diagram of another embodiment of the invention with one compensation circuit 82. The basic arrangement of the energy transmission system according to the embodiment in Figs. 8a and 8b corresponds to the embodiment in Fig. 5, in particular the arrangement of coils 2 and the circuit compensatory 82.
[0066] This solution uses equation (6), by adjusting the number of turns of compensation circuit 82. The total compensation circuit 82 has the same number of turns 81 as all coils 2. However, as shown in Figure 8a, additional switches 80 only allow connection parts of the compensation turns to the AC generator of the power supply 5. For example, if two 2 'transmission circuits are activated, only 1/2 of the compensation turns 81 are activated. If three 2 'transmission circuits are activated, only 1/3 of the compensation turns 81, etc. are activated. The turns of the compensation circuit 82 are tightly coupled, as indicated by the thickened line under each compensation inductor, showing parts of the winding. Fig.8b shows the "snapshot" of the embodiment from Fig.8a in the operating state where two 2 'transmission circuits are activated. As shown, the switch 80 'connects half of the turns 81 of the compensation circuit 82 to the power supply 5 and thus to the AC voltage generator.
[0067] Although the invention has been illustrated and described in detail in the drawings and in the previous description, such illustrations and description should be regarded as illustrative or exemplary and not limiting. All or some of the embodiments or features of individual embodiments may be combined without limitation. The invention is not limited to the embodiments described.
[0068] For example, it is possible to operate the invention in accordance with the above embodiments in which:
- Controller 3 is an external unit, i.e. it is a microcontroller or a computer,
- Detectors 4 are pressure detectors, field detectors, ultrasonic proximity detectors or optical detectors, and the device 10 is adapted to them,
- Coils 2 are in many layers of a printed circuit or are separate coils,
- Soft magnetic plates 6, 12 contain a ferritic plastic composite material or a high permeability structural metal foil made of mumetal, metallic glass or nanocrystalline iron,
- Soft magnetic plates 6, 12 are in the form of printed circuit layers,
- Device 10 includes or not alternative batteries instead of battery 15, e.g. "supercapacitor",
- Switches 31, 80 and 80 'are relays or transistors, e.g. field effect transistors (FETs) or field effect transistors with a metal-oxide semiconductor (MOSFET) structure and / or
- Generator circuits are arranged in many layers.
[0069] In addition, it is possible to operate the invention in accordance with the above embodiments, where the AC compensation voltage supplied to the 2 ", 52 or 82 compensation circuits is not determined by equation (6). However, during calibration (e.g. in the factory or in the laboratory) the optimal AC compensation voltage is determined for each combination of activated 2 'transmission circuits. This optimal configuration is stored in controller 3 and used during operation. The optimal setting is determined by a magnetic field sensor located in a far field. The AC compensation voltage is changed until the minimum magnetic field is measured.
[0070] Alternatively or in addition to this, the AC compensation voltage supplied to the 2 ", 52 or 82 compensation circuits is determined in a feedback system or during active operation, where the far magnetic field is detected using a suitable sensor, e.g. a Hall sensor connected to controller 3. The sensor may be located far enough from coil 2, e.g. on the outer edge of the base unit 1 or the transmission area, or it can be a separate unit, wired or wirelessly connected to the controller 3. Controller 3 changes the AC compensation voltage until optimal suppression is achieved.
[0071] Other changes from the illustrated embodiments may be requested and implemented by those skilled in the art while working with the claimed invention, based on the study of the drawings, description and the appended claims. In the claims, the word "containing" does not exclude other elements or steps, and the indefinite article ("a" or "an") does not exclude the plural. A single processor or other assembly may perform the functions of several items cited in the claims. The mere fact that some measures are invoked in mutually different dependent claims does not mean that the combination of these measures cannot be used to the advantage. The computer program may be stored / distributed on a suitable medium, such as an optical medium or SSD medium provided with computer hardware or as part of it, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. Any reference marks in the claims should not be construed as limiting its scope.
20 members in 11 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 08103351 | European Patent Office (EPO) | A | |
| 2009051346 | International Bureau of the World Intellectual Property Organization (WIPO) | W |
Members20
| Document | Office | Kind | |
|---|---|---|---|
| WO2009122355A2 | World Intellectual Property Organization (WIPO) | A2 | |
| TW200950250A | Taiwan Province of China | A | |
| WO2009122355A3 | World Intellectual Property Organization (WIPO) | A3 | |
| KR20100129334A | Republic of Korea | A | |
| EP2263296A2 | European Patent Office (EPO) | A2 | |
| US2011025133A1 | United States of America | A1 | |
| JP2011517265A | Japan | A | |
| CN102089952A | China | A | |
| RU2010144968A | Russian Federation | A | |
| RU2010144968A | Russian Federation | A | |
| RU2506678C2 | Russian Federation | C2 | |
| CN102089952B | China | B | |
| JP5474927B2 | Japan | B2 | |
| US8810071B2 | United States of America | B2 | |
| BRPI0906538A2 | Brazil | A2 | |
| EP2263296B1 | European Patent Office (EPO) | B1 | |
| ES2556269T3 | Spain | T3 | |
| KR101604600B1 | Republic of Korea | B1 | |
| PL2263296T3This record | Poland | T3 | |
| BRPI0906538B1 | Brazil | B1 |
Numbers
- Application
- 9728260
Titles2
- English
- WIRELESS POWER TRANSMISSION SYSTEM
- Polish
- BEZPRZEWODOWY SYSTEM TRANSMISJI ENERGII
Classification
- CPC, 8
- H02J50/402
- H02J50/10
- H01F17/0006
- H01F38/14
- H02J50/90
- H02J50/80
- H02J50/70
- H04B5/263
- IPC, 3
- H02J4 25
- H01F17 00
- H01F38 14