Eddy current loss control method and system, and wireless charging device

Abstract

The invention provides an eddy current loss control method and system, and a wireless charging device, and the method comprises the steps: obtaining an excitation current generated through a power transmitting device and an induction current generated through a power receiving device, and generating an eddy current loss curve of a housing of the power receiving device based on the current phase difference and amplitude of the excitation current and the induction current; and performing current phase difference adjustment according to the eddy-current loss curve, and controlling the eddy-current loss of the shell of the power receiving equipment within a preset interval. The eddy-current loss curve of the power receiving equipment shell is generated through the current phase difference and the amplitude of the excitation current and the induction current, then the change condition of the eddy-current loss generated by the power receiving equipment shell is searched according to the eddy-current loss curve, and the current phase difference is controlled within a proper interval. Therefore, the eddy-current loss of the shell of the power receiving equipment is controlled at a relatively low level while the power transmitting equipment and the power receiving equipment carry out efficient wireless power transmission.

Description

Technical Field

[0001] The present invention relates to the field of medical equipment and temperature control technology, and in particular to an eddy current loss control method and system, and a wireless charging device. Background Art

[0002] Since biocompatibility needs to be considered for implantable devices, titanium or titanium alloy is usually used as the shell, and the surface of the shell is flat and smooth to reduce foreign body reaction. At present, some implantable medical devices use wireless charging technology, which results in the alternating magnetic field generating large eddy currents in the metal shell when the implanted device is wirelessly charged. The eddy currents flow through the metal shell and dissipate in the form of Joule heat, causing severe local heating. At present, many technologies for reducing eddy current losses are more complex to control, such as using implant temperature feedback control strategies to control charging start and stop or charging power, or grooving the metal shell. These two methods will not only increase control costs and prolong charging time; they will also add additional processing technology, which is difficult to apply on a large scale, and the level of eddy current loss suppression is limited. Summary of the invention

[0003] In view of the shortcomings of the prior art described above, an object of the present invention is to provide an eddy current loss control method and system, and a wireless charging device, for solving the problem of reducing the large eddy current loss generated on the metal casing during wireless charging of an implanted device in the body, thereby causing local temperature rise.

[0004] To achieve the above object and other related objects, the present invention provides an eddy current loss control method, comprising the following steps:

[0005] Acquire an excitation current and an induced current; wherein the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device;

[0006] generating an eddy current loss curve of the housing of the power receiving device based on a current phase difference and a current amplitude between the excitation current and the induced current;

[0007] The current phase difference is adjusted according to the eddy current loss curve to control the eddy current loss of the power receiving device housing within a preset range.

[0008] In one embodiment of the present invention, the process of obtaining the excitation current and the induced current includes:

[0009] Using the power transmitting device to connect to an AC power source, and generating an excitation current and an alternating magnetic field through a coil in the power transmitting device; and,

[0010] When the power receiving device is located in the magnetic field space of the alternating magnetic field, an induced current is generated by the coil in the power receiving device.

[0011] In one embodiment of the present invention, before obtaining the excitation current and the induced current, the method further includes:

[0012] Coils are respectively provided in the power transmitting device and the power receiving device; and / or,

[0013] The power transmitting device is disposed outside a target area, and the power receiving device is disposed inside the target area.

[0014] In one embodiment of the present invention, if the target area includes a human tissue area, the method further includes:

[0015] A rechargeable implantable medical device implanted inside a human tissue region is used as the power receiving device; and

[0016] A charging device located outside the human tissue area and cooperating with the rechargeable implantable medical device to perform wireless charging is used as the power transmitting device.

[0017] In one embodiment of the present invention, the rechargeable implantable medical device includes a rechargeable brain pacemaker, a rechargeable cardiac pacemaker, a rechargeable spinal cord stimulator, a rechargeable implantable brain-computer interface and / or a rechargeable implantable drug infusion pump.

[0018] In one embodiment of the present invention, the process of adjusting the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range includes:

[0019] A compensation circuit is provided according to the power transmitting device and the power receiving device; and,

[0020] The current phase difference is adjusted according to the eddy current loss curve, and when the coil in the power receiving device and the compensation capacitor in the compensation circuit are fully compensated, the eddy current loss of the power receiving device housing is controlled to be in the middle value of the preset range.

[0021] The present invention also provides an eddy current loss control system, the system comprising:

[0022] A current acquisition module, used to obtain an excitation current and an induced current; wherein the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device;

[0023] An eddy current loss curve module, used to generate an eddy current loss curve of the housing of the power receiving device according to the current phase difference and current amplitude between the excitation current and the induced current;

[0024] The eddy current loss control module is used to adjust the current phase difference according to the eddy current loss curve to control the eddy current loss of the power receiving device housing within a preset range.

[0025] The present invention also provides a wireless charging device, which is applied to any of the eddy current loss control methods described above, or to the eddy current loss control system described above, wherein the wireless charging device includes a power transmitting device and a power receiving device;

[0026] When the power transmitting device is connected to an AC power source, the coil in the power transmitting device generates an excitation current and an alternating magnetic field;

[0027] When the power receiving device is located in the magnetic field space of the alternating magnetic field, the coil in the power receiving device generates an induced current.

[0028] In an embodiment of the present invention, if the housing of the power receiving device is made of a metal housing or an alloy housing, when the power receiving device is located in the magnetic field space of the alternating magnetic field, the power receiving device is heated up.

[0029] In one embodiment of the present invention, the shell of the power receiving device includes a first shell and a second shell. After the first shell and the second shell are matched and connected, a cavity is formed between the first shell and the second shell, and a coil, a magnetic core, a metal shielding layer, a battery and a circuit connection board are arranged inside the cavity.

[0030] As described above, the present invention provides an eddy current loss control method and system, and a wireless charging device, which have the following beneficial effects: by obtaining the excitation current and the induced current, and then based on the current phase difference and current amplitude between the excitation current and the induced current, an eddy current loss curve of the housing of the power receiving device is generated; then the current phase difference is adjusted according to the eddy current loss curve, and the eddy current loss of the housing of the power receiving device is controlled within a preset range. Among them, the excitation current is generated by the power transmitting device, and the induced current is generated by the power receiving device. It can be seen that the present invention generates an eddy current loss curve of the housing of the power receiving device through the current phase difference and current amplitude between the excitation current and the induced current, and then finds the change of the eddy current loss generated by the housing of the power receiving device according to the eddy current loss curve, and then controls the current phase difference in a suitable range, so that while satisfying the power transmitting device and the power receiving device for efficient wireless power transmission, the eddy current loss of the housing of the power receiving device can also be controlled at a lower level. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic flow chart of an eddy current loss control method provided in one embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the generation principle of eddy current provided by an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of electric field vector decomposition provided in an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of a curve of eddy current loss variation provided by an embodiment of the present invention;

[0035] Figure 5 A schematic diagram of a compensation circuit connection provided in an embodiment of the present invention;

[0036] Figure 6 A simplified structural diagram of a power transmitting device and a receiving device provided in an embodiment of the present invention;

[0037] Figure 7 A schematic diagram of a model structure of a power transmitting device and a receiving device provided in an embodiment of the present invention;

[0038] Figure 8 A schematic cross-sectional view of a power transmitting device and a receiving device provided in one embodiment of the present invention;

[0039] Fig. 9 The model structure simulation analysis results of the power transmitting device and the receiving device provided in one embodiment of the present invention;

[0040] Fig.10 A simplified schematic diagram of the model structure of a power transmitting device and a receiving device provided in an embodiment of the present invention;

[0041] Fig.11 A schematic diagram of a curve of eddy current loss variation provided by another embodiment of the present invention;

[0042] Fig.12 A schematic diagram of the hardware modules of an eddy current loss control system provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following is an explanation of the embodiments of the present invention by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It is understood that the following embodiments and the features in the embodiments can be combined with each other without conflict. In addition, it is understood that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the drawings instead of being drawn according to the number, shape and size of the components during actual implementation. The type, quantity and proportion of each component during actual implementation can be a random change, and the component layout type may also be more complicated.

[0044] Figure 1 A schematic flow chart of a method for controlling eddy current loss is shown. Specifically, in an exemplary embodiment, Figure 1 As shown, this embodiment provides an eddy current loss control method, comprising the following steps:

[0045] S110, obtaining an excitation current and an induced current; wherein the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device. In this embodiment or other embodiments, the process of obtaining the excitation current and the induced current may include: connecting an AC power supply using a power transmitting device, and generating an excitation current and an alternating magnetic field through a coil in the power transmitting device; and, when the power receiving device is located in the magnetic field space of the alternating magnetic field, generating an induced current through the coil in the power receiving device. In this embodiment or other embodiments, the power receiving device may also be referred to as a receiving side, and the power transmitting device may also be referred to as a transmitting side. In this embodiment or other embodiments, the coil in the power transmitting device may be recorded as a transmitting coil, abbreviated as TX or a transmitting coil TX; the coil in the power receiving device may be recorded as a receiving coil, abbreviated as RX or a receiving coil RX.

[0046] S120, generating an eddy current loss curve of the housing of the power receiving device based on the current phase difference and current amplitude between the excitation current and the induced current.

[0047] S130, adjusting the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range.

[0048] It can be seen that this embodiment generates an eddy current loss curve of the power receiving device housing through the current phase difference and current amplitude between the excitation current and the induced current, and then finds the change of the eddy current loss generated by the power receiving device housing according to the eddy current loss curve, and then controls the current phase difference within a suitable range, so that the eddy current loss of the power receiving device housing can be controlled at a lower level while satisfying the efficient wireless power transmission between the power transmitting device and the power receiving device.

[0049] In an exemplary embodiment, before obtaining the excitation current and the induced current, it may also include: setting coils in the power transmitting device and the power receiving device respectively; and / or setting the power transmitting device outside the target area, and setting the power receiving device inside the target area. As an example, coils may be set in the power transmitting device and the power receiving device respectively, and the power transmitting device may be set outside the target area, and the power receiving device may be set inside the target area. In this embodiment or other embodiments, the target area includes but is not limited to an area formed by human tissue, referred to as a human tissue area.

[0050] In an exemplary embodiment, if the target area includes a human tissue area, it may also include: using a rechargeable implantable medical device implanted inside the human tissue area as a power receiving device; and using a charging device located outside the human tissue area and cooperating with the rechargeable implantable medical device for wireless charging as a power transmitting device. As an example, in this embodiment or other embodiments, the rechargeable implantable medical device includes but is not limited to a rechargeable brain pacemaker, a rechargeable cardiac pacemaker, a rechargeable spinal cord stimulator, a rechargeable implantable brain-computer interface, a rechargeable implantable drug infusion pump, etc.

[0051] In an exemplary embodiment, the process of adjusting the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range includes: setting a compensation circuit according to the power transmitting device and the power receiving device; and adjusting the current phase difference according to the eddy current loss curve, and controlling the eddy current loss of the housing of the power receiving device to an intermediate value of the preset range when the coil in the power receiving device and the compensation capacitor in the compensation circuit are fully compensated.

[0052] According to the above records, in some examples corresponding to the embodiments, if the power transmitting device is composed of a charging device located outside the human tissue, and the power receiving device is composed of a rechargeable implantable medical device located inside the human tissue, then when the charging device and the rechargeable implantable medical device are wirelessly charged, the alternating magnetic field generated by the transmitting coil will generate a changing magnetic field in the space around the receiving coil. When there is a metal conductor near the receiving coil, the alternating magnetic field will induce eddy currents inside it. The eddy currents flowing through the metal casing will cause the electrical energy to dissipate in the form of Joule heat. This thermal effect may cause the local temperature of the receiving side to rise. Since the power receiving device is implanted in the body and is in close contact with the human tissue, the temperature rise caused by its eddy current loss will directly affect the temperature of nearby human tissue, bringing some safety risks. Figure 2 As shown, Figure 2 The schematic diagram shows the principle of eddy current generation on the metal shell of a rechargeable implantable medical device, which consists of a pair of coupled coils plus an LCC-S compensation network. Figure 2 In, L f To compensate the inductance, C f , C1 and C2 are compensation capacitors, u s is the AC input voltage, u L The alternating magnetic field generated by the coupling coil acts on each point on the metal shell near the receiving coil RX, which will generate an electric field vector E. 总 , E 总 Under the action of eddy current, the total eddy current loss Where σ is the conductivity and V is the volume of the metal shell. 总 It can also be decomposed into E generated by the current of the transmitting coil TX and the receiving coil RX acting separately TX and E RX The sum of the vectors, such as Figure 3 As shown. The excitation current of the transmitting coil TX is i TX , θ is its phase, and the induced current of the receiving coil RX is i RX , the induced current i RX With the excitation current i TX The phase difference is recorded as The phase difference It is the key variable for eddy current loss regulation and control. Based on the current phase difference and current amplitude between the excitation current and the induced current, the eddy current loss of the metal shell of the rechargeable implantable medical device can be obtained as a function of the phase difference. The change curve of Figure 4 As shown in the figure, it can be seen from the change curve of eddy current loss that the eddy current loss increases with the phase difference. As the angle increases, it decreases, and decreases fastest near 90°. When the angle increases beyond 90°, the effect of reducing eddy current loss gradually weakens. The eddy current loss tends to be flat when approaching 180°.

[0053] At the same time, in order to control the eddy current loss of the power receiving device housing within a preset range, a compensation circuit can be set according to the charging device and the rechargeable implantable medical device. For the rechargeable implantable medical device, a compensation network can be designed to compensate for the self-inductance of the receiving coil RX. Taking the SS compensation method as an example, the compensation circuit connection diagram is as follows Figure 5 As shown, in Figure 5 Middle,U in is the AC input, U out is the AC output, L P is the self-inductance of the transmitting coil TX, Ls is the self-inductance of the receiving coil RX, C P is the primary compensation capacitor, used to compensate for L P , C S is the secondary compensation capacitor, used to compensate for L S When the compensation capacitor Cs on the receiving side fully compensates the self-inductance Ls of the receiving coil RX, the reactive power on the receiving side is minimal, which facilitates the load to receive more power. At this time, the current angle between the transmitting coil TX and the receiving coil RX is 90°, and the eddy current loss on the receiving side is at an intermediate value in the preset range. If the current angle between the transmitting coil TX and the receiving coil RX is appropriately increased, the eddy current loss on the receiving side can be effectively reduced. If the angle continues to increase after exceeding 90°, the effect of reducing eddy current loss will gradually weaken, and the reactive power will increase significantly. In order to make the load obtain equal power, the external charging device needs to continuously increase the transmission power, which is not conducive to rechargeable implantable medical devices with low transmission efficiency and low transmission power. Therefore, the phase difference between the transmitting and receiving currents can be made to exceed 90°, but not too much. Preferably, making the phase difference between the transmitting and receiving currents 90° to 120° is a range with obvious benefits, that is, the eddy current loss preset range can be set according to the current phase difference of 90° to 120°. When the phase difference When the angle increases from 90° to 120°, the eddy current loss is reduced by about 38%, and the reduction effect is obvious. The specific selection of the current phase difference value in the range of 90° to 120° can be determined according to the proportion of eddy current loss to the total loss. The more the eddy current loss is the main loss, the more it is necessary to increase the current phase difference between the transmitting coil TX and the receiving coil RX to suppress it.

[0054] It can be seen that by adjusting the current phase difference between the transmitting coil and the receiving coil, the eddy current loss of the metal shell of the rechargeable implantable medical device can be controlled at a low level, without the need for complex charging start-stop control strategies, and without the need to add additional components and process means, the temperature rise of the rechargeable implantable medical device can be reduced at low cost and high reliability. That is, by reducing the value of the receiving side compensation capacitor Cs, that is, by appropriately overcompensating to make the secondary side capacitive, the phase angle of the transmitting and receiving currents can be increased. By making the phase angle of the transmitting and receiving currents fall within the range of 90° to 120°, the reactive power on the receiving side can be relatively small while the eddy current loss can be greatly reduced, thereby effectively reducing the heat generation of the rechargeable implantable medical device.

[0055] According to the above records, in one example, a rechargeable brain pacemaker is used as an implantable power receiving device in the body, and the rechargeable brain pacemaker is recorded as the receiving side, and the external power transmitting device that performs wireless charging with the rechargeable brain pacemaker is recorded as the transmitting side. The eddy current loss on the receiving side can be analyzed first, and the transmitting side can be simplified. The corresponding structural diagram is as follows: Figure 6 As shown, in Figure 6 In the figure, 1 is an external power transmitting device, and 2 is an internally implanted power receiving device. In some embodiments, the external power transmitting device may also be referred to as a power transmitting device, and the internally implanted power receiving device may also be referred to as a power receiving device. When analyzing the eddy current loss on the receiving side, a three-dimensional modeling software may be used for modeling and simulation analysis. The schematic diagram of the three-dimensional modeling structure is shown in FIG. Figure 7 and Figure 8 The corresponding model simulation analysis results are shown in Fig. 9 As shown. Figure 8 In the figure, 1 is an external power transmitting device, 11 is a transmitting side magnetic core, 12 is a transmitting coil TX, 2 is an internal implanted power receiving device, 21 is a first shell or a metal upper cover, 22 is a receiving coil RX, 23 is a receiving side magnetic core, 24 is a metal shielding layer, 25 is a battery, 26 is a PCB (Printed Circuit Board, PCB for short), and 27 is a second shell or a metal lower cover. Fig. 9From the simulation analysis results, it can be obtained that when there is an alternating current in the transmitting coil TX and there is no alternating current in the receiving coil RX, as shown in parameter 1, a certain eddy current loss is generated on the metal structure on the receiving side, and the eddy current loss is concentrated in the metal upper cover part of the receiving side shell, and the eddy current loss on other metal structures (such as metal shielding layer 24, battery 25, PCB, metal lower cover 27, etc.) is small enough to be negligible. When there is an alternating current in both the transmitting coil TX and the receiving coil RX, the total eddy current loss on the metal structure on the receiving side increases, but the eddy current loss is still concentrated in the metal upper cover part of the receiving side shell, and the eddy current loss on other metal structures is small enough to be negligible. Therefore, the model can be further simplified, and only the metal upper cover that mainly generates eddy current loss is retained for analysis. The simplified analysis model is as follows Fig.10 As shown, the subsequent analysis can be based on Fig.10 The simplified model shown is carried out.

[0056] right Fig.10 The simplified model shown in the figure is used for simulation analysis. Fig. 9 Change the phase angle of the receiving and transmitting current under the condition of parameter 2 and the outer diameter D of the transmitting coil TX TX , the change of eddy current loss is obtained as Fig.11 As shown. Fig.11 It can be seen that in the case of several transmitting coils TX with different outer diameters, the eddy current loss increases with the phase angle. The outer diameter D of the transmitting coil TX is TX =32mm is used as an example. When , eddy current loss Peddy=418.4mW, when When the eddy current loss Peddy = 267.1mW, compared with The eddy current loss is reduced by 36.2% and the effect of reducing eddy current loss is very obvious. Figure 4 The theoretical analysis results show that Fig.11 The simulation results show that the eddy current loss varies with the current phase angle. The changing trend of is completely consistent with the theoretical analysis results. The reduction degree of eddy current loss is also consistent when the angle increases from 90° to 120°.

[0057] According to the above records, in some other examples, rechargeable cardiac pacemakers, rechargeable spinal cord stimulators, rechargeable implantable brain-computer interfaces, rechargeable implantable drug infusion pumps, etc. can also be used as in vivo implantable power receiving devices. The corresponding working principles refer to the above-mentioned rechargeable brain pacemakers, which will not be repeated here. Therefore, by adjusting the current phase difference between the transmitting side coil and the receiving side coil, the eddy current loss of the metal casing of the rechargeable implantable medical device can be controlled at a low level. There is no need for complex charging start-stop control strategies, nor is there any need to add additional components and process means. The temperature rise of rechargeable implantable medical devices such as rechargeable brain pacemakers can be reduced at low cost and high reliability.

[0058] In summary, the present invention provides an eddy current loss control method, which generates an eddy current loss curve of the housing of a power receiving device by obtaining an excitation current and an induced current, and then based on the current phase difference and current amplitude between the excitation current and the induced current; and then adjusts the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range. Among them, the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device. It can be seen that the method generates an eddy current loss curve of the housing of a power receiving device through the current phase difference and current amplitude between the excitation current and the induced current, and then finds the change of the eddy current loss generated by the housing of the power receiving device according to the eddy current loss curve, and then controls the current phase difference within a suitable range, so that while satisfying the efficient wireless power transmission between the power transmitting device and the power receiving device, the eddy current loss of the housing of the power receiving device can also be controlled at a lower level. When the power receiving device is a rechargeable implantable medical device located in human tissue, and the power transmitting device is an external charging device that cooperates with the rechargeable implantable medical device for wireless charging, the eddy current loss of the metal casing of the rechargeable implantable medical device can be controlled at a low level by adjusting the current phase difference between the excitation current corresponding to the coil in the external charging device and the induced current corresponding to the coil in the rechargeable implantable medical device. There is no need for a complicated charging start-stop control strategy, nor is there any need to add additional components and process means. The temperature rise of the rechargeable implantable medical device can be reduced at low cost and with high reliability.

[0059] In another exemplary embodiment of the present invention, Fig.12 As shown, an eddy current loss control system is also provided, comprising:

[0060] The current acquisition module 1210 is used to obtain the excitation current and the induced current; wherein the excitation current is generated by the power transmitting device, and the induced current is generated by the power receiving device. In this embodiment or other embodiments, the process of obtaining the excitation current and the induced current may include: connecting the AC power supply by using the power transmitting device, and generating the excitation current and the alternating magnetic field by the coil in the power transmitting device; and, when the power receiving device is located in the magnetic field space of the alternating magnetic field, generating the induced current by the coil in the power receiving device. In this embodiment or other embodiments, the power receiving device may also be referred to as the receiving side, and the power transmitting device may also be referred to as the transmitting side. In this embodiment or other embodiments, the coil in the power transmitting device may be recorded as a transmitting coil, abbreviated as TX or a transmitting coil TX; the coil in the power receiving device may be recorded as a receiving coil, abbreviated as RX or a receiving coil RX.

[0061] The eddy current loss curve module 1220 is used to generate an eddy current loss curve of the housing of the power receiving device according to the current phase difference and current amplitude between the excitation current and the induced current;

[0062] The eddy current loss control module 1230 is used to adjust the current phase difference according to the eddy current loss curve, so as to control the eddy current loss of the housing of the power receiving device within a preset range.

[0063] In an exemplary embodiment, before obtaining the excitation current and the induced current, it may also include: setting coils in the power transmitting device and the power receiving device respectively; and / or setting the power transmitting device outside the target area, and setting the power receiving device inside the target area. As an example, coils may be set in the power transmitting device and the power receiving device respectively, and the power transmitting device may be set outside the target area, and the power receiving device may be set inside the target area. In this embodiment or other embodiments, the target area includes but is not limited to an area formed by human tissue, referred to as a human tissue area.

[0064] In an exemplary embodiment, if the target area includes a human tissue area, it may also include: using a rechargeable implantable medical device implanted inside the human tissue area as a power receiving device; and using a charging device located outside the human tissue area and cooperating with the rechargeable implantable medical device for wireless charging as a power transmitting device. As an example, in this embodiment or other embodiments, the rechargeable implantable medical device includes but is not limited to a rechargeable brain pacemaker, a rechargeable cardiac pacemaker, a rechargeable spinal cord stimulator, a rechargeable implantable brain-computer interface, a rechargeable implantable drug infusion pump, etc.

[0065] In an exemplary embodiment, the process of adjusting the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range includes: setting a compensation circuit according to the power transmitting device and the power receiving device; and adjusting the current phase difference according to the eddy current loss curve, and controlling the eddy current loss of the housing of the power receiving device to an intermediate value of the preset range when the coil in the power receiving device and the compensation capacitor in the compensation circuit are fully compensated.

[0066] It can be understood that the eddy current loss control system provided in the above embodiment and the eddy current loss control method provided in the above embodiment belong to the same concept, wherein the specific manner in which the eddy current loss control method performs the operation has been described in detail in the above method embodiment, and will not be repeated here. In practical applications, the eddy current loss control system provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the eddy current loss control system into different functional modules, and then implement all or part of the functions of the corresponding functional modules through the eddy current loss control method described in the above embodiment, and this is not specifically limited here.

[0067] In summary, the present invention provides an eddy current loss control system, which generates an eddy current loss curve of the housing of a power receiving device by obtaining an excitation current and an induced current, and then based on the current phase difference and current amplitude between the excitation current and the induced current; and then adjusts the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range. Among them, the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device. It can be seen that the system generates an eddy current loss curve of the housing of a power receiving device through the current phase difference and current amplitude between the excitation current and the induced current, and then finds the change of the eddy current loss generated by the housing of the power receiving device according to the eddy current loss curve, and then controls the current phase difference within a suitable range, so that while satisfying the efficient wireless power transmission between the power transmitting device and the power receiving device, the eddy current loss of the housing of the power receiving device can also be controlled at a lower level. When the power receiving device is a rechargeable implantable medical device located in human tissue, and the power transmitting device is an external charging device that cooperates with the rechargeable implantable medical device for wireless charging, the eddy current loss of the metal casing of the rechargeable implantable medical device can be controlled at a low level by adjusting the current phase difference between the excitation current corresponding to the coil in the external charging device and the induced current corresponding to the coil in the rechargeable implantable medical device. There is no need for a complicated charging start-stop control strategy, nor is there any need to add additional components and process means. The temperature rise of the rechargeable implantable medical device can be reduced at low cost and with high reliability.

[0068] In another exemplary embodiment of the present invention, a wireless charging device is provided, which is applied to the eddy current loss control method as described in the above embodiment, or to the eddy current loss control system as described in the above embodiment. The wireless charging device includes a power transmitting device and a power receiving device; when the power transmitting device is connected to an AC power source, the coil in the power transmitting device generates an excitation current and an alternating magnetic field; when the power receiving device is located in the magnetic field space of the alternating magnetic field, the coil in the power receiving device generates an induced current.

[0069] According to the above description, in an exemplary embodiment, if the housing of the power receiving device is made of a metal housing or an alloy housing, the power receiving device will heat up when the power receiving device is located in a magnetic field space of an alternating magnetic field.

[0070] According to the above records, in an exemplary embodiment, the shell of the power receiving device includes a first shell and a second shell. After the first shell and the second shell are matched and connected, a cavity is formed between the first shell and the second shell, and a coil, a magnetic core, a metal shielding layer, a battery and a circuit connection board are arranged inside the cavity.

[0071] According to the above records, in one example, the structural schematic diagram of the three-dimensional modeling of the above wireless charging device is as follows: Figure 7 and Figure 8 As shown, in Figure 8 In the figure, 1 is an external power transmitting device, 11 is a transmitting side magnetic core, 12 is a transmitting coil TX, 2 is an internally implanted power receiving device, 21 is a first shell, 22 is a receiving coil RX, 23 is a receiving side magnetic core, 24 is a metal shielding layer, 25 is a battery, 26 is a PCB, and 27 is a second shell; wherein the first shell 21 can also be referred to as a metal upper cover, and the second shell 27 can also be referred to as a metal lower cover.

[0072] It can be understood that the power transmitting device and the power receiving device included in the wireless charging device and the corresponding specific execution operation methods have been described in detail in the above-mentioned eddy current loss control method and / or eddy current loss control system embodiments, and will not be repeated here.

[0073] It is understood that, although the terms first, second, etc. may be used to describe the housings, etc. in the embodiments of the present invention, these terms are only used to distinguish the housings from each other. For example, without departing from the scope of the embodiments of the present invention, the first housing may also be referred to as the second housing, and similarly, the second housing may also be referred to as the first housing.

[0074] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for controlling eddy current loss, characterized in that: The method comprises: Acquire an excitation current and an induced current; wherein the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device; generating an eddy current loss curve of the housing of the power receiving device based on a current phase difference and a current amplitude between the excitation current and the induced current; The current phase difference is adjusted according to the eddy current loss curve to control the eddy current loss of the power receiving device housing within a preset range.

2. The eddy current loss control method according to claim 1, characterized in that: The process of obtaining the excitation current and the sense current includes: Using the power transmitting device to connect to an AC power source, and generating an excitation current and an alternating magnetic field through a coil in the power transmitting device; and, When the power receiving device is located in the magnetic field space of the alternating magnetic field, an induced current is generated by the coil in the power receiving device.

3. The eddy current loss control method according to claim 1 or 2, characterized in that: Before obtaining the excitation current and the induced current, the method further includes: Coils are respectively provided in the power transmitting device and the power receiving device; and / or, The power transmitting device is disposed outside a target area, and the power receiving device is disposed inside the target area.

4. The eddy current loss control method according to claim 3, characterized in that: If the target area includes a human tissue area, the method further includes: A rechargeable implantable medical device implanted inside a human tissue region is used as the power receiving device; and A charging device located outside the human tissue area and cooperating with the rechargeable implantable medical device to perform wireless charging is used as the power transmitting device.

5. The eddy current loss control method according to claim 4, characterized in that: The rechargeable implantable medical device includes a rechargeable brain pacemaker, a rechargeable cardiac pacemaker, a rechargeable spinal cord stimulator, a rechargeable implantable brain-computer interface and / or a rechargeable implantable drug infusion pump.

6. The eddy current loss control method according to claim 1, characterized in that: The process of adjusting the current phase difference according to the eddy current loss curve to control the eddy current loss of the housing of the power receiving device within a preset range includes: A compensation circuit is provided according to the power transmitting device and the power receiving device; and, The current phase difference is adjusted according to the eddy current loss curve, and when the coil in the power receiving device and the compensation capacitor in the compensation circuit are fully compensated, the eddy current loss of the power receiving device housing is controlled to be in the middle value of the preset range.

7. An eddy current loss control system, characterized in that: The system comprises: A current acquisition module, used to obtain an excitation current and an induced current; wherein the excitation current is generated by a power transmitting device, and the induced current is generated by a power receiving device; An eddy current loss curve module, used to generate an eddy current loss curve of the housing of the power receiving device according to the current phase difference and current amplitude between the excitation current and the induced current; The eddy current loss control module is used to adjust the current phase difference according to the eddy current loss curve to control the eddy current loss of the power receiving device housing within a preset range.

8. A wireless charging device, applied to the eddy current loss control method as claimed in claims 1 to 6, or applied to the eddy current loss control system as claimed in claim 7, characterized in that: The wireless charging device includes a power transmitting device and a power receiving device; When the power transmitting device is connected to an AC power source, the coil in the power transmitting device generates an excitation current and an alternating magnetic field; When the power receiving device is located in the magnetic field space of the alternating magnetic field, the coil in the power receiving device generates an induced current.

9. The wireless charging device according to claim 8, characterized in that: If the housing of the power receiving device is made of a metal housing or an alloy housing, the power receiving device will heat up when the power receiving device is located in the magnetic field space of the alternating magnetic field.

10. The wireless charging device according to claim 8 or 9, characterized in that: The shell of the power receiving device includes a first shell and a second shell. After the first shell and the second shell are matched and connected, a cavity is formed between the first shell and the second shell. A coil, a magnetic core, a metal shielding layer, a battery and a circuit connection board are arranged inside the cavity.

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