SYSTEM AND METHOD FOR CONTROLLING WIRELESS POWER TRANSMISSION

Abstract

Method for controlling a wireless power transmission system (100), the method comprising: generating, with a transmitting coil (112), a first magnetic field (120) of a first magnitude; magnetically coupling a receiving coil (122) to the transmitting coil (112) to generate a second magnetic field (138) of a second magnitude; determining, with an electronic processor coupled to the transmitting coil (112) and communicatively coupled to the receiving coil (122), at least one selected from the group consisting of the first magnitude of the first magnetic field (120) and a first current magnitude of a current in the transmitting coil (112); receiving, by the electronic processor, at least one selected from the group consisting of the second magnitude of the second magnetic field (138) and a second current magnitude of a current in the receiving coil (122);Determining, by the electronic processor, an efficiency based on at least one of the group consisting of the first quantity, the second quantity, the first current quantity, and the second current quantity; determining, in response to the efficiency exceeding an efficiency threshold: a first phase of the first magnetic field (120); a second phase of the second magnetic field (138); a phase difference based on the first phase and the second phase; a coil orientation based on the phase difference; and a power level for the transmitting coil (112) based on the efficiency and the coil orientation.

Description

BACKGROUND OF THE INVENTION

[0001] Battery-powered portable electronic devices are used for a variety of purposes. For example, public safety personnel (such as police officers or other first responders) may use communication and recording devices that are useful while performing their duties. In another example, people who hike, mountaineer, climb, hunt, or engage in similar outdoor recreational activities may use a portable electronic device (such as a navigation device) to enhance their recreational experience.

[0002] Wireless power transfer systems were developed to recharge the batteries of such devices. These systems transmit electrical power without wired connections, for example, using inductive or resonant magnetic coupling. List of characters

[0003] The accompanying figures, in which the same reference numerals refer to identical or functionally similar elements in the individual views, are incorporated together with the detailed description below and form part of the specification and serve to further illustrate embodiments of concepts comprising the claimed invention and explain various principles and advantages of these embodiments. Fig. Figure 1 is a diagram of a wireless power transmission system according to some embodiments. Fig. Figure 2 is a diagram of a transmitting coil according to some embodiments. Fig. Figure 3 is a perspective view of a transmitting coil aligned with a receiving coil according to some embodiments. Fig. Figure 4 is a cross-sectional view of a transmitting coil aligned with a receiving coil according to some embodiments. Fig. Figure 5 is a cross-sectional view of a transmitting coil misaligned with a receiving coil according to some embodiments. Fig. Figure 6 is a graphical representation illustrating the relationship between efficiency and coil displacement according to some embodiments. Fig. Figure 7 is a graphical representation illustrating the relationship between magnetic field strength ratio, wireless power transmission efficiency and coil displacement according to some embodiments. Fig. Figure 8 is a graphical representation illustrating the relationship between magnetic field phase difference, efficiency and coil displacement according to some embodiments. Fig. Figure 9 is a flowchart of a procedure for controlling the wireless power transmission system from Fig. 1 according to some embodiments.

[0004] Experts will recognize that elements in the figures are shown for the sake of simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated compared to others to improve the understanding of embodiments of the present invention.

[0005] Where appropriate, the apparatus and process components have been represented by conventional symbols in the drawings, which show only the specific details relevant to understanding the embodiments of the present invention, so as not to obscure the disclosure with details that are easily deducible to an average person skilled in the art who has the benefit of this description. DETAILED DESCRIPTION OF THE INVENTION

[0006] An exemplary embodiment provides a method for controlling a wireless power transmission system. The method comprises generating a first magnetic field of a first magnitude using a transmitting coil. The method further comprises magnetically coupling a receiving coil to the transmitting coil to generate a second magnetic field of a second magnitude. The method further comprises determining the first magnitude of the first magnetic field using an electronic processor that is electrically coupled to the transmitting coil and communicatively coupled to the receiving coil. The method further comprises receiving the second magnitude of the second magnetic field using the electronic processor. The method further comprises determining an efficiency based on the first magnitude and the second magnitude using the electronic processor.The procedure also includes determining, by the electronic processor, a power level for the transmitting coil based on the efficiency.

[0007] Another exemplary embodiment provides a wireless power transmission system. The system includes a transmitting coil with a first magnetic field of a first magnitude. The system further includes a receiving coil, magnetically coupled to the transmitting coil, with a second magnetic field of a second magnitude. The system further includes an electronic processor, electrically coupled to the transmitting coil and communicatively coupled to the receiving coil. The electronic processor is configured to determine the magnitude of the first magnetic field. The electronic processor is further configured to receive the second magnitude of the second magnetic field. The electronic processor is further configured to determine an efficiency based on the first and second magnitudes and, based on the efficiency, to determine a power level for the transmitting coil.

[0008] The term "wireless power transfer," as used herein, refers to the wireless transmission of electrical power by the inductive or resonant coupling of two or more coils. Coils thus coupled are referred to herein as magnetically coupled. Wireless power transfer by resonant coupling involves operating the coils at a resonant frequency that is the same for both coils. A wireless power transfer device (for example, a battery charger) can be used to recharge the batteries of a portable electronic device. In certain types of wireless power transfer devices, a transmitting coil is excited at an operating frequency that produces an oscillating magnetic field. The battery or portable electronic device, which contains a receiving coil tuned to the same operating frequency, is placed near the transmitting coil.The oscillating magnetic field induces an electric current in the receiving coil, which is used to power battery charging circuits. Efficient wireless power transfer can occur when the transmitting and receiving coils are substantially aligned. The efficiency of wireless power transfer is the ratio of electrical power received by the receiving coil to the electrical power transmitted by the transmitting coil. Generally, resonant coupling achieves a higher efficiency of resonant wireless power transfer compared to inductive coupling. However, the power transfer efficiency is reduced if the coils are misaligned, which generally increases the amount of transmit power required to charge the batteries for a given time, or conversely, reduces the amount of energy received for a given transmit power and charging time.

[0009] Fig. Figure 1 is a block diagram of an exemplary embodiment of a wireless power transmission system. 100 The wireless power transmission system 100 includes a wireless power transmitter 102 and a wireless power receiver 104 In some embodiments, the wireless power transmitter 102 a wireless battery charger or is integrated into one and the wireless power receiver 104 is a portable electronic device (for example, a smartphone) or is integrated into one that contains a battery which is charged when the wireless power receiver 104 magnetically with the wireless power transmitter 102 is coupled. In some embodiments, the wireless power receiver can 104be integrated into a wearable electronic device in the form of a smart garment (for example, a smart vest) that contains various integrated electronic components for monitoring, support, or communication for the wearer.

[0010] The wireless power transmitter 102 includes an electronic controller 106 of the transmitter, a high-frequency amplifier (“(RF) amplifier”) 108, a transmit impedance matching network 110 , a transmitting coil 112 , a ferrite-supported transmitting coil shield 113 , a first magnetic field sensor 114 , a first transceiver 116 and a first antenna 118 The wireless power transmitter 102It may also contain other components, for example one or more resonant circuits, a suitable power source (for example, a battery or a mains rectifier), and other circuits that are not shown for clarity. The aforementioned components of the wireless power transmitter 102 are connected to various other modules and components via one or more electrical connections, which may include, for example, control or data buses that enable communication between them. The use of control and data buses for connecting and exchanging information between the various modules and components would be obvious to a person skilled in the art based on the description presented here. To simplify the description, the following is included in Fig. 1 wireless power transmitter shown 102Each embodiment contains only one of the listed components. Alternative embodiments may include more or less of each of these components, combine some components, or include other alternative components. The components can be integrated into the wireless power transmitter. 102 They can be integrated or externally coupled and modular, for example to allow the removal or addition of some of the components.

[0011] The electronic controller 106 The transmitter is electrically connected to the high-frequency amplifier. 108 , the transmit impedance matching network 110 , the first magnetic field sensor 114 and the first transceiver 116 coupled. In an exemplary embodiment, the electronic controller 106The transmitter contains a microcontroller that includes at least one electronic processor, memory, and an input / output interface. The electronic processor executes computer-readable instructions ("software") stored in the memory to control the high-frequency amplifier. 108 and the transmit impedance matching network 110 , as described herein, to wirelessly transmit electrical power via the transmitting coil 112 to transfer.

[0012] The high-frequency amplifier 108 It receives a direct current (DC) signal from a power source (not shown). The electronic controller 106 The transmitter controls the high-frequency amplifier 108 to output an amplified alternating current (AC) electrical signal at a predetermined operating frequency. The operating frequency of the wireless power transmitter 102 is the same as the operating frequency of the wireless power receiver 104As an expert will recognize, the operating frequency is determined, among other things, by the physical properties of the transmitting coil. 112 and resonant circuits, for example one or more capacitors connected to the transmitting coil 112 are coupled, which are not shown or described here for the sake of clarity. The electronic controller 106 The transmitter also controls the power level of the signal from the high-frequency amplifier. 108 generated alternating current electrical signal to control the amount of wirelessly transmitted power.

[0013] The alternating current electrical signal is fed to the transmit impedance matching network. 110 supplied. The electronic controller 106 The transmitter controls the transmit impedance matching network. 110 , to power the high-frequency amplifier 108 efficiently with the transmitting coil 112 to couple.

[0014] The transmitting coil 112receives the alternating current signal from the transmit impedance matching network 110 The alternating electrical current in the transmitting coil 112 generates a first magnetic field 120 The first magnetic field 120 is a time-varying magnetic field that oscillates at the same frequency as the alternating current signal that generated it (i.e., the operating frequency).

[0015] As an expert can recognize, resonant coupling systems can contain more than one coil on the transmitter side and more than one coil on the receiver side. For the sake of simplicity, the transmitting coil will be referred to here. 112 described in the form of a single coil. In one example, the transmitting coil 112 A flat-wound multi-helix coil with a generally planar shape. The transmitting coil 112It can, for example, have a circular, rectangular, or square shape. The ferrite-supported transmitting coil shielding 113 It includes a metallic shielding layer and a ferrite layer and is arranged in such a way that other components of the wireless power transmitter 102 generally against all from the transmitting coil 112 outgoing electromagnetic fields are shielded. In some embodiments, the transmission shielding is ferrite-supported. 113 positioned so that the ferrite layer is closer to the transmitting coil 112 is the metallic shielding layer.

[0016] In an exemplary embodiment, the first magnetic field sensor includes 114 a wire loop that is centered and essentially coplanar to the transmitting coil 112 is positioned. The first magnetic field 120induces an electromotive force that leads to an electrical signal at the loop terminals, which, via a suitable circuit (not shown), controls the electronic controller. 106 of the transmitter, or both, is processed to determine the size and phase of the first magnetic field. 120 to determine. The first magnetic field sensor 114 is electrically connected to the electronic controller 106 of the transmitter to connect to the electronic controller 106 of the transmitter with measurements of the size and phase of the first magnetic field 120 to provide.

[0017] The first transceiver 116 is electrically connected to the electronic controller 106 of the sensor and the first antenna 118 coupled and includes a high-frequency transceiver that enables wireless communication via the first antenna 118provides this information using suitable network modalities (for example, Bluetooth™, Near Field Communication (NFC), Wi-Fi™, and the like). Alternative embodiments may include an audio transceiver, a light transceiver, or other suitable near-field communication mechanisms. As shown, the first transceiver couples 116 the electronic controller 106 the transmitter communicates with the wireless power receiver 104 The first transceiver 116It includes other components that enable wireless communication (for example, amplifiers, baseband processors, and the like), which are not described here for brevity and which can be implemented in hardware, software, or a combination of both. Some embodiments include multiple transceivers or separate transmit and receive components (for example, a transmitter and a receiver) instead of a combined transceiver. In alternative embodiments, the first transceiver 116 instead of or in addition to the first antenna 118 with the transmitting coil 112 electrically coupled.

[0018] The wireless power receiver 104 includes a receiving coil 122 , a ferrite-supported receiving coil shield 123 , a receiving impedance matching network 124 , a rectifier 126 , a burden 128 , an electronic controller130 of the receiver, a second magnetic field sensor 132 , a second transceiver 134 and a second antenna 136 The wireless power receiver 104 It may also include other components, for example one or more resonant circuits, a suitable power source (for example, a battery or a mains rectifier), and other circuits that are not shown for clarity. The aforementioned components of the wireless power receiver 104are coupled together with other various modules and components via one or more electrical connections, which may include, for example, control or data buses that enable communication between them. The use of control and data buses for the connection between and the exchange of information among the various modules and components is obvious to a person skilled in the art based on the present description. For the sake of simplicity, the wireless power receiver includes 104 , who in Fig. Figure 1 illustrates only one of the components shown. Alternative embodiments may contain more or less of each of these components, combine some components, or include other alternative components. The components can be integrated into the wireless power receiver. 104It can be integrated or externally coupled and modular, for example to allow the removal or addition of some components.

[0019] As an expert will recognize, the first magnetic field induces 120 (according to Faraday's law of induction) an alternating electric current in the receiving coil 122 , when the transmitting coil 112 near the receiving coil 122 is positioned. (As with the transmitting coil) 112 The receiving coil 122 (described here for simplicity as a single coil.) The alternating electric current in the receiving coil 122 This in turn generates a second magnetic field. 138 , which is essentially opposite to the first magnetic field 120 is. The alternating electrical current in the receiving coil 122 and the resulting second magnetic field 138They oscillate at the operating frequency. In some embodiments, the receiving coil 122 in the shape and composition of the transmitting coil 112 similar and is in relation to the ferrite-supported receiving coil shielding 123 similarly positioned.

[0020] The alternating current electrical signal from the receiving coil 122 is added to the receiving impedance matching network 124 supplied. The electronic controller 130 The receiver controls the receiving impedance matching network. 124 , to the rectifier 126 and the burden 128 efficiently with the receiving coil 122 to couple. The rectifier 126 The rectifier, which may include a full-wave rectifier, receives the alternating current and converts it into a direct current signal. 126It may include other electronic components (for example, filters and voltage converters) which are not described here for the sake of brevity.

[0021] The rectifier 126 feeds the DC signal to the load 128 In some embodiments, the load 128 a battery pack (that is, one or more batteries) and suitable electronic components for charging the battery pack using the DC signal. In some embodiments, the load can 128 This may also include other electronic systems or components (for example, a charging circuit for an external device) that can be operated directly with the wirelessly received power.

[0022] The electronic controller 130 The receiver's impedance matching network is electrically connected to the receiver impedance matching network. 124 , the rectifier 126 , the burden 128 , the second magnetic field sensor 132and the second transceiver 134 coupled. The electronic controller 130 The receiver contains similar components to the electronic controller 106 of the transmitter and controls the components of the wireless power receiver 104 , to wirelessly transmit electrical power via the receiving coil 122 to receive and this performance of the load 128 to provide.

[0023] The second magnetic field sensor 132 contains similar components to the first magnetic field sensor 114 and is similarly constructed. Accordingly, the second magnetic field sensor 132 Measurements of the magnitude and phase of the second magnetic field 138 the electronic controller 130 available to the recipient.

[0024] The second transceiver 134 contains similar components to the first transceiver 116and is similarly configured. Accordingly, the second transceiver 134 electrically coupled to the electronic controller 130 of the receiver and the second antenna 136 and couples the electronic controller 130 the receiver communicates with the wireless power transmitter 102 In alternative embodiments, the second transceiver 134 instead of or in addition to the second antenna 136 with the receiving coil 122 electrically coupled.

[0025] Fig. Figure 2 is an example graphical representation of the transmitting coil. 112 and the ferrite-supported transmitting coil shielding 113 The transmitting coil is shown below. 112 and the ferrite-supported transmitting coil shielding 113 They are positioned concentrically to each other and are essentially similar in shape and size. As mentioned above, the ferrite-supported transmit shielding is... 113with the ferrite layer towards the transmitting coil 112 positioned in the Fig. In the example shown, the transmitting coil 112 It has a rectangular shape, is sixty millimeters long (that is, along the X-axis) and forty millimeters wide (that is, along the Y-axis). The following examples are used in the context of a transmitting coil. 112 and a receiving coil 122 described, each with an associated sensor and ferrite-supported shielding, as described in Fig. 2 illustrated, arranged and each having the shape and dimensions as shown in Fig. Figure 2 is shown. A person skilled in the art will recognize that the dimensions given herein are only approximate and exemplary, and that the actual dimensions will differ from the examples given. It should also be noted that the systems and methods described herein are not limited in their use to those shown in Figure 2. Fig. The 2 coils shown are not limited to this application, but can also be used with coils of different shapes and dimensions.

[0026] As already mentioned, electrical power transmission occurs wirelessly through magnetic induction when the transmitting coil 112 near the receiving coil 122 is positioned. Fig. Figure 3 illustrates the transmitting coil 112 and the receiving coil 122 essentially parallel and aligned with each other (that is, there is no lateral displacement in the X-axis or the Y-axis) and by an intermediate coil spacing 140 separate. The efficiency of wireless power transmission (that is, the ratio between the power received by the receiving coil) 122 received electrical power compared to that from the transmitting coil 112 (transmitted electrical power) increases with the distance between the coils 140 away.

[0027] The efficiency of wireless power transmission also varies depending on the orientation of the transmitting coil. 112 with the receiving coil 122 The transmitting coil 112 It does not need to be precise with the receiving coil. 122 It must be aligned to enable wireless power transmission. However, the efficiency of wireless power transmission decreases when the lateral displacement (i.e., misalignment) increases along either the X-axis or the Y-axis. According to Lenz's law, the power in the receiving coil 122 induced electric current creates a second magnetic field 138 generates a magnetic field that is essentially opposite to the first magnetic field 120 is caused by the alternating current in the transmitting coil 112 is produced. As in Fig. As shown in section 4, the coil displacement is 142 (that is, the displacement between the geometric center of the transmitting coil) 112 and the geometric center of the receiving coil122 ) zero and the intermediate coil spacing 140 is significantly smaller than the transverse dimensions (X, Y) of the coils. If the coils are as in Fig. When positioned as shown in 4, a substantial magnetic field cancellation occurs because the first magnetic field 120 almost completely with the second magnetic field 138 is linked and is essentially opposite to this. However, if the coil displacement increases 142 as in Fig. 5 shows the first magnetic field 120 and the second magnetic field 138 It is not aligned and the magnetic field cancellation is reduced. It should be noted that in the Fig. 4 and Fig. 5. The flux lines shown only indicate the presence and approximate location of the first magnetic field. 120 and the second magnetic field 138They represent, for the sake of clarity, not a complete and precise representation of the size, shape, and location of the first magnetic field. 120 and the second magnetic field 138 offer.

[0028] The in Fig. 6 shown graphic 150 shows the relationship between the efficiency of wireless power transmission (line 152 ) and the coil displacement 142 (in the Y direction), where the parameters of the transmit impedance matching network 110 and the parameters of the receive impedance matching network 124 were selected to maximize wireless power transmission. As shown, the efficiency of wireless power transmission generally decreases with increasing coil displacement. 142 As shown by the graphic 150 As illustrated, the efficiency drops rapidly to near zero when the coil displacement 142increases to approximately twenty-nine millimeters. This indicates the distance at which minimal magnetic field coupling occurs and, consequently, minimal magnetic field cancellation. The efficiency of wireless power transmission can also be related to the ratio of the inductance in the receiving coil. 122 induced electric current by the first magnetic field 120 to the electric current that is in the transmitting coil 112 through the high-frequency amplifier 108 is generated. As in Fig. 7 shown (graphic) 155 The ratio of two currents relative to the coil displacement in the X-direction can be determined from the magnitudes of the two magnetic fields generated by these currents. For example, the squared ratio of the magnitude of the second magnetic field is... 138 (H_Rx) to the size of the first magnetic field 120 (H_Tx), shown in line 157, essentially the same as the efficiency of wireless power transmission (line) 159 Therefore, it is possible to calculate the efficiency of wireless power transmission from the squared ratio of the magnetic field strengths (|H_Rx / H_Tx|). 2 ) to determine. As described herein, the efficiency of the wireless power can be used to adjust the transmit power and other system parameters.

[0029] As in Fig. As shown in 7, some values ​​correspond to |H_Rx / H_Tx| 2 more than one value of the coil displacement 142 Additionally, increasing the distance between the coils also results in... 140 (see Fig. 3) in a lower efficiency of wireless power transmission and therefore produces a lower value for the size of |H_Rx / H_Tx| 2 In this case, a coil displacement may occur erroneously. 142 can be determined to be non-zero, even if the transmitting coil 112with the receiving coil 122 is aligned (that is, the coil displacement) 142 is actually zero). Accordingly, as in Fig. Figure 8 shows that the phase shift between H_Rx and H_Tx is used to increase confidence in the coil displacement estimate. 142 to increase by determining whether the displacement is smaller or larger than the distance at which the sign change of the phase difference occurs. As in the Fig. 6 and Fig. As illustrated in Figure 7, the distance at which the sign change occurs generally corresponds to the distance at which minimal magnetic field cancellation occurs. For example, for coils, as in Fig. Figure 2 shows the change of sign at twenty-nine millimeters in the Y direction ( Fig. 6) and at forty-five millimeters in the X direction ( Fig. 7) Coils of other dimensions produce a sign change at other distances, which can be determined experimentally.

[0030] Fig. Figure 8 shows a graphic 165 , which describes the relationship between the phase difference (Δφ) between H_Tx and H_Rx (line 167 ) and the coil displacement 142 (in the Y direction). As shown, the sign of the phase difference reverses at a specific coil displacement. 142 um (that is, twenty-nine millimeters, represented in point) 169 ). Before point 169 The value of the phase difference is positive and after point 169 The value is negative. As in Fig. As shown in Figure 8, each value of Δφ yields only one value for the coil displacement. 142 , in contrast to efficiency (line 171Therefore, as explained in more detail below, the phase difference can be used to determine whether a given efficiency indicates that the coils are misaligned, or whether the distance between the coils exceeds the usual distance for efficient power transmission.

[0031] Fig. 9 presents an exemplary procedure 200 for controlling the wireless power transmission system 100 The procedure is presented as an example. 200 based on the wireless power transmitter 102 described. This should not be considered restrictive. The procedures described herein could be used on the wireless power transmitter. 102 , the wireless power receiver 104 , a combination of the two, an external electronic processor that communicates with the wireless power transmitter 102 is coupled and the wireless power receiver 104or a combination of the aforementioned.

[0032] At Block 202 A communication link will be established between the electronic controller 106 of the transmitter and the electronic controller 130 of the receiver. In some embodiments, this communication link is established between the first transceiver 116 and the second transceiver 134 established via the first antenna 118 and the second antenna 136 In alternative embodiments, the transmitting coil 112 and the receiving coil 122 each time in place of the first antenna 118 and the second antenna 136 used.

[0033] At Block 204 The electronic controller controls 106 the transmitter's components of the wireless power transmitter 102 as described above, to generate the first magnetic field 120to generate. In some embodiments, the first magnetic field 120 generated using a predetermined power level (that is, a quantity) that is sufficient to supply the load 128 of the wireless power receiver 104 is suitable. In alternative embodiments, the first magnetic field 120 generated using a series of short diagnostic current bursts to determine a power level for the first magnetic field 120 and an approximate displacement between the coils, based on the efficiency and the phase difference, as described in more detail below. The first magnetic field 120 induces an electric current in the receiving coil 122 , which is at block 206 in turn a second magnetic field 138 generated.

[0034] At Block 208 The electronic controller determines 106The transmitter's first quantity. In an exemplary embodiment, the first quantity is the magnitude of the field strength of the first magnetic field. 120 (H_Tx), as seen through the first magnetic field sensor 114 is being detected. At Block 210 The electronic controller receives 106 The transmitter provides a second quantity. In one exemplary embodiment, the second quantity is the field strength of the second magnetic field. 138 (H_Rx). The second quantity is determined by the second magnetic field sensor. 132 sensed and by the electronic controller 130 of the recipient via the block 202 established communication link to the electronic controller 106 sent by the sender.

[0035] At Block 212 The electronic controller determines 106The transmitter's efficiency is determined based on the first and second quantities. In an exemplary embodiment, the electronic controller determines 106 The transmitter's efficiency of wireless power transmission can be determined by calculating the ratio of the second quantity to the first quantity |H_Rx / H_Tx|. 2 In some embodiments, current measurements can be used instead of magnetic field strength measurements to determine the efficiency. For example, the first quantity measured in Block can be 208 The magnitude of the current flowing into the transmitting coil is determined. 112 is supplied, as measured by a current sensor, and the second quantity, which is measured at block 210 The size of the signal received is determined by the size of the signal in the receiving coil. 122 induced current, as measured by a current sensor. In such cases, the efficiency at block 212 determined by calculating a ratio based on the current quantities.

[0036] At Block 214 The electronic controller determines 106 of the transmitter, whether an efficiency threshold has been reached. The efficiency threshold is the efficiency level below which the wireless power transmitter ceases to function. 102 will not attempt to send power to the wireless power receiver 104 to transmit. In some embodiments, the threshold can be based, for example, on the maximum output of the high-frequency amplifier. 108 available power can be determined (for example, the high-frequency amplifier can be used). 108 be unable to provide sufficient power for the load 128(for example, at efficiencies below 50%, or such power levels might not be desirable). In other embodiments, the threshold is determined based on other factors or combinations of factors. If the efficiency threshold is not reached, the electronic controller... 106 of the transmitter, the first magnetic field 120 to generate and tests the efficiency of the blocks 204 until 214 until the threshold is reached.

[0037] When the efficiency threshold is reached, the electronic controller determines 106 of the sender at Block 216 a transmission power level for the first magnetic field 120 The transmission power level is based on the efficiency. For example, if the electronic controller 106If the transmitter determines that the efficiency of the wireless power transmission is 70%, it can increase the transmission power level to increase the amount of transmitted power, so that the wireless power receiver 104 receives as much power as it would at optimal efficiency.

[0038] At Block 218 The electronic controller determines 106 of the transmitter a first phase for the first magnetic field 120 (Ph(H_Tx)), as from the first magnetic field sensor 114 Sensed. At Block 220 The electronic controller receives 106 of the transmitter a second phase for the second magnetic field 138 (Ph(H_Rx)). The second phase is determined by the second magnetic field sensor 132 sensed and by the electronic controller 130 of the recipient via the block 202 established communication link to the electronic controller 106 sent by the sender.

[0039] At Block 222 The electronic controller determines 106 The transmitter's phase difference (Δφ) is determined by subtracting Ph(H_Rx) from Ph(H_Tx). At block 224 The electronic controller determines 106 The transmitter uses the phase difference to estimate the coil orientation. For example, the electronic controller 106 The transmitter's phase difference is stored in a memory of the electronic controller. 106 Compare the data stored by the transmitter regarding coil displacement (for example, graph). 165 from Fig. 8) Based on this coil displacement, the electronic controller determines 106 of the transmitter, whether the coils are substantially aligned or not. In one embodiment, the electronic controller 106 The transmitter's coil displacement is compared to the value stored in a memory of the electronic controller. 106the sender's stored graphic 165 compare ( Fig. 8) For example, the electronic controller 106 of the transmitter determine that the coils are essentially aligned when Δφ>0, while the opposite is found when Δφ<0.

[0040] At Block 226 The electronic controller determines 106 the transmitter's transmission power level for the first magnetic field 120 based on efficiency and coil orientation. For example, if the electronic controller 106 If the transmitter determines that the coils are not substantially aligned, it can determine a power level of zero because too much power would be dissipated before reaching the receiving coil. 122is received. In another example, it can be determined that the coils are aligned, but too far apart for effective power transmission at the current power settings, if the electronic controller 106 The transmitter determines that the coils are essentially aligned and that the efficiency for aligned coils is lower than expected. In this case, the aligned magnetic fields would allow for higher power transmission than in the non-aligned case. Accordingly, the electronic controller 106 The transmitter determines that the transmission power level should be increased to improve power transfer to the wireless power receiver. Another example is the electronic controller. 106of the transmitter determine that the transmission power is set to a level so that a specific absorption rate (SAR) is maintained that complies with the applicable legal limits.

[0041] In alternative embodiments, determining the transmission power level (in the case of the blocks) includes 216 and 226 ) the adjustment of the impedance of the transmitting coil 112 and the receiving coil 122 by controlling the transmit impedance matching network 110 or the receiving impedance matching network 124 , to improve the efficiency of wireless power transmission.

[0042] If the electronic controller 106 the transmitter determines that the transmission power level is greater than zero (block 228 ), the electronic controller drives 106 of the transmitter, to monitor the sizes and phases of the magnetic fields in order to monitor the blocks 208 until 226to adjust the transmission power level. If the electronic controller 106 of the transmitter determines that the transmission power level is not greater than zero (block 228 ), the electronic controller starts 106 the sender's procedure 200 new by establishing a communication link (in the case of block 202 ).

[0043] The specific absorption rate (SAR) is a measure of the amount of energy absorbed by the body when using a radio frequency device. Various government regulations limit the specific absorption rates for radio frequency devices. A decrease in efficiency due to misaligned coils can lead to an increase in the specific absorption rate because of reduced magnetic field cancellation. Likewise, an increase in efficiency resulting from substantially aligned coils can result in a decrease in the specific absorption rate. As a person skilled in the art can recognize, the systems and methods described herein can therefore be used to determine the specific absorption rate for different values ​​of coil displacements. 142 can be used at a given transmission power.

[0044] Specific embodiments have been described in the preceding specification. However, a person skilled in the art can recognize that various modifications and changes can be made without departing from the scope of protection of the invention as defined in the following claims. Accordingly, the specification and the figures are to be understood in an illustrative rather than a limiting sense, and all such modifications are to fall within the scope of protection of the present teachings.

[0045] The benefits, advantages, problem solutions, and any conceivable element that leads to or enhances any benefit, advantage, or solution shall not be construed as critical, necessary, or essential features or elements of any claim or all claims. The invention is defined exclusively by the attached claims, including any amendment made during the validity period of the present application and all equivalent such claims as published.

[0046] Furthermore, in this document, relational expressions such as first and second, above and below, and the like are to be used solely to distinguish one entity or action from another, without necessarily requiring or implying any actual relationship or order between such entities or actions. The expressions "includes," "comprising," "has," "having," "include," "containing," "containing," or any variation thereof are to cover non-exclusive inclusion, so that a process, procedure, article, or device that includes, has, includes, or contains a list of elements may not only include such elements but may also include other elements not expressly listed or inherent in such processes, procedures, articles, or devices. An element that continues with "includes... a," "has..."The terms "one," "includes... one," and "contains... one" do not, without further stipulations, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprise, have, include, or contain the element. The terms "one" and "a" are defined as one or more unless explicitly stated otherwise herein. The terms "essentially," "essentially," "approximately," "about," or any other version thereof are defined as "being close to" as is clear to those skilled in the art, and in one non-limiting embodiment, the term is defined as being within 10%, in another embodiment within 5%, in another embodiment within 1%, and in yet another embodiment within 0.5%. The term "coupled," as used herein, is defined as "connected," although not necessarily directly and not necessarily mechanically.A device or structure that is “configured” in a certain way is configured at least in that way, but may also be configured in at least one other way not listed.

[0047] It is desired that some embodiments include one or more generic or specialized processors (or “processing devices”), such as microprocessors, digital signal processors, custom processors and freely programmable field-gate arrays (FPGAs) and unique stored program instructions (comprising both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuitry, some, most or all of the functions of the method and / or device described herein.Alternatively, some or all functions can be implemented by a state machine that has no stored program instructions, or in one or more application-specific integrated circuits (ASICs) where each function, or some combinations of certain functions, are implemented as custom logic. Naturally, a combination of the two approaches can be used.

[0048] Furthermore, an embodiment can be implemented as a computer-readable storage medium containing computer-readable code stored thereon for programming a computer (which, for example, includes a processor) to perform a method described and claimed herein. Examples of such computer-readable storage media include, but are not limited to: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (read-only memory), a PROM (programmable read memory), an EPROM (erasable programmable read memory), an EEPROM (electrically erasable programmable read memory), and flash memory.Furthermore, it can be expected that a person skilled in the art, regardless of possible considerable effort and a large selection of designs, which is justified, for example, by available time, current technology and economic considerations, guided by the concepts and principles disclosed herein, will be able to produce such software instructions, programs and ICs with minimal experimental effort.

[0049] The summary of the disclosure is provided to allow the reader to quickly grasp the nature of the technical disclosure. It is submitted with the understanding that it is not intended to interpret or limit the spirit or meaning of the claims. Furthermore, it is clear from the preceding detailed description that various features in different embodiments are grouped together to streamline the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly stated in each claim. Rather, as is evident from the following claims, an inventive subject matter is present in fewer than all the features of any single disclosed embodiment.Thus, the following claims are integrated into the detailed description, with each claim standing alone as a separately claimed subject matter.

Claims

[1] Method for controlling a wireless power transmission system, comprising: the generation, using a transmitting coil, of a first magnetic field of a first magnitude; the magnetic coupling of a receiving coil to the transmitting coil to generate a second magnetic field with a second magnitude; Determining, with an electronic processor coupled to the transmitting coil and communicatively coupled to the receiving coil, at least one selected from the group consisting of the first quantity of the first magnetic field and a first current quantity of a current in the transmitting coil; the reception, by the electronic processor, of at least one selected from the group consisting of the second quantity of the second magnetic field and a second current quantity of a current in the receiving coil; Determining, by the electronic processor, an efficiency based on at least one of the group consisting of the first quantity, the second quantity, the first current quantity, and the second current quantity; and Determining, by the electronic processor, a power level for the transmitting coil based on the efficiency. [2] Method according to claim 1, wherein determining the efficiency comprises determining a ratio based on the first quantity and the second quantity. [3] Method according to claim 1, wherein determining an efficiency comprises determining a ratio based on the first current quantity and the second current quantity. [4] Method according to claim 1, further comprising: the generation, with a high-frequency amplifier, of a large number of diagnostic current bursts. [5] Method according to claim 1, further comprising: the matching, by the electronic processor, based on the efficiency of at least one of the group consisting of a first impedance for the transmitting coil and a second impedance for the receiving coil. [6] Method according to claim 1, further comprising: the determination, by the electronic processor, of a first phase of the first magnetic field; the reception, by the electronic processor, of a second phase of the second magnetic field; Determining, by the electronic processor, a phase difference based on the first phase and the second phase; and Determining, by the electronic processor, a coil alignment based on the phase difference. [7] Method according to claim 6, further comprising: Determining, by the electronic processor, a power level for the transmitting coil based on the coil alignment. [8] Method according to claim 6, further comprising: Determining, by the electronic processor, a power level for the transmitting coil based on the efficiency and the coil orientation. [9] Method according to claim 6, further comprising: the matching, by the electronic processor, of at least one of the group consisting of a first impedance for the transmitting coil and a second impedance for the receiving coil, based on the efficiency and the coil alignment. [10] Wireless power transmission system, the system includes: a transmitting coil, with a first magnetic field of a first size; a receiving coil, magnetically coupled to the transmitting coil, with a second magnetic field of a second magnitude; and an electronic processor that is electrically coupled to the transmitting coil and communicatively coupled to the receiving coil and that is configured to Determine at least one selected from the group consisting of the first quantity of the first magnetic field and a first current quantity of a current in the transmitting coil; Receive at least one selected from the group consisting of the second quantity of the second magnetic field and a second current quantity of a current in the receiving coil; Determining an efficiency based on at least one of the following: the first quantity, the second quantity, the first current quantity, and the second current quantity; and Determining a power level for the transmitting coil based on the efficiency. [11] System according to claim 10, wherein the electronic processor is further configured to determine a ratio based on the first quantity and the second quantity. [12] System according to claim 10, wherein the electronic processor is further configured to determine a ratio based on the first current quantity and the second current quantity. [13] System according to claim 10 further comprising: a high-frequency amplifier which is electrically coupled to the electronic processor, wherein the electronic processor is further configured to Generate, using the high-frequency amplifier, a large number of diagnostic current bursts. [14] System according to claim 10 further comprising: a first impedance matching network that is electrically coupled to the electronic processor; and a second impedance matching network that is communicatively coupled to the electronic processor, wherein the electronic processor is further configured to match, based on efficiency, at least one of the group consisting of a first impedance for the first impedance matching network and a second impedance for the second impedance matching network. [15] System according to claim 10, wherein the electronic processor is further configured to Determining a first phase of the first magnetic field; Receiving a second phase of the second magnetic field; Determining a phase difference based on the first phase and the second phase; and Determining a coil alignment based on the phase difference. [16] System according to claim 15, wherein the electronic processor is further configured to determine a power level for the transmitting coil based on the coil orientation. [17] System according to claim 15, wherein the electronic processor is further configured to determine a power level for the transmitting coil based on the efficiency and the coil orientation. [18] System according to claim 15, further comprising: a first impedance matching network that is electrically coupled to the electronic processor; and a second impedance matching network that is communicatively coupled to the electronic processor, wherein the electronic processor is further configured to match, based on the efficiency and coil orientation, at least one of a group consisting of a first impedance for the first impedance matching network and a second impedance for the second impedance matching network.