Transmitting circuit frequency modulation feedback control method and wireless energy transmission device

Abstract

The present invention relates to the field of medical equipment, and in particular to a frequency modulation feedback control method for a transmitting circuit and a wireless energy transmission device. A first control module calculates a target phase reference according to the difference between a charging parameter and a parameter reference. The first control module determines whether the target phase reference is in an adjustable range of the phase reference. If so, the target phase reference is output as the phase reference. If not, a preset phase difference corresponding to the target phase reference is output as the phase reference. A second control module calculates an operating frequency according to the difference between the phase difference and the phase reference, and adjusts the current of the resonant circuit according to the operating frequency to ensure that the transmitting circuit always operates in an inductive zone or a capacitive zone, and the current changes in a single manner with the transmitting frequency, thereby solving the technical problem of cross-zone operation of the circuit caused by resonant frequency drift, and then the collapse of the feedback adjustment mechanism.

Description

Technical Field

[0001] The present invention relates to the field of medical equipment, and in particular to a frequency modulation feedback control method for a transmitting circuit and a wireless energy transmission device. Background Art

[0002] Implantable medical systems often use magnetic coupling / magnetic resonance technology for wireless power supply or wireless charging. By increasing the coil current, the transmitted magnetic field is enhanced. However, during wireless charging, the temperature of metal parts in implantable medical devices often increases as the magnetic field increases. Therefore, while ensuring normal charging, it is necessary to control the transmission power, reduce heat generation, and ensure the thermal safety of human tissue.

[0003] In vitro wireless charging devices often use LC resonant circuits to control power or current by adjusting the transmission frequency, but the current does not change monotonically with frequency, and the current is maximum at the resonant frequency point. When the circuit operating frequency is less than the resonant frequency, the resonant circuit operates in the capacitive region, and when the circuit operating frequency is greater than the resonant frequency, the resonant circuit operates in the inductive region. In order to prevent the resonant frequency from drifting and causing the circuit to operate across the capacitive and inductive regions, a margin is generally left when the operating frequency range is preset, such as more than 1% away from the resonant frequency point. However, this method is difficult to apply to resonant circuits with high quality factors Q (such as more than 200), because when the Q value is high, the effective operating frequency range can only be in a very narrow area near the resonant frequency point. Therefore, the drift of the resonant frequency point of the high Q value resonant circuit can easily cause the circuit operating frequency to cross the region, which in turn causes the feedback logic to be reversed and the regulation mechanism to collapse. Summary of the invention

[0004] In view of this, the present invention provides a frequency modulation feedback control method for a transmitting circuit and a wireless energy transmission device to solve the technical problem of cross-region operation of the circuit caused by resonant frequency drift, and then feedback logic inversion and regulation mechanism collapse.

[0005] A first aspect of the present invention provides a frequency modulation feedback control method for a transmitting circuit, wherein the transmitting circuit includes a resonant circuit provided with a transmitting coil, including:

[0006] S10 obtains the current charging parameter and calculates the target phase reference according to the difference between the charging parameter and the parameter reference;

[0007] S20 determines whether the target phase reference is within the phase reference adjustable interval;

[0008] S21: If yes, use the target phase reference as the phase reference;

[0009] If no, S22 uses the preset phase difference corresponding to the target phase reference as the phase reference, wherein the preset phase difference is within the adjustable range of the phase reference;

[0010] S30 collects the phase difference of the resonant circuit and calculates the operating frequency according to the difference between the phase difference and the phase reference;

[0011] S40 adjusts the current of the resonant circuit according to the operating frequency, and executes S10 again after a preset time interval.

[0012] Further, in some embodiments of the present invention, the charging parameter includes the current of the transmitting coil, and the parameter reference includes the current reference;

[0013] The obtaining of the current charging parameter and calculating the target phase reference according to the difference with the parameter reference includes:

[0014] The current of the current transmitting coil is obtained and the target phase reference is calculated according to the difference between the current and the current reference.

[0015] Furthermore, in some embodiments of the present invention, obtaining the current of the current transmitting coil and calculating the target phase reference according to the difference between the current and the current reference further includes:

[0016] Obtaining receiving parameters of the wireless energy receiving end;

[0017] The current reference is calculated according to a difference between the received parameter and a predetermined parameter.

[0018] Further, in some embodiments of the present invention, the receiving parameter includes receiving power, and the predetermined parameter includes predetermined power;

[0019] Calculating the current reference according to the difference between the received parameter and the predetermined parameter includes:

[0020] Regularly reading the received power of the wireless energy receiving end;

[0021] Calculating the current value of the resonant circuit in the next cycle according to the difference between the received power and the predetermined power;

[0022] The calculated current value is used as the current reference.

[0023] Further, in some embodiments of the present invention, determining whether the target phase reference is within the phase reference adjustable interval includes:

[0024] Determine whether the target phase reference is greater than or equal to an adjustable threshold value A, 0≤adjustable threshold value A<90°; or

[0025] It is determined whether the target phase reference is less than or equal to an adjustable threshold value B, where -90°<adjustable threshold value B≤0.

[0026] Further, in some embodiments of the present invention, determining whether the target phase reference is greater than or equal to A includes:

[0027] If yes, taking the target phase reference as the phase reference;

[0028] If not, the preset phase difference A corresponding to the target phase reference is used as the phase reference, and the adjustable threshold value A≤preset phase difference A<90°;

[0029] Determining whether the target phase reference is less than or equal to an adjustable threshold B includes:

[0030] If yes, taking the target phase reference as the phase reference;

[0031] If not, the preset phase difference B corresponding to the target phase reference is used as the phase, and the adjustable threshold B≤preset phase difference B<-90°.

[0032] Furthermore, in some embodiments of the present invention, collecting the phase difference of the resonant circuit includes:

[0033] The phase difference between the current of the transmitting coil and the voltage at the resonant tank port is collected.

[0034] A second aspect of the present invention provides a wireless energy transmission device, comprising a first control module, a second control module, a frequency generation module and a transmitting circuit, wherein the transmitting circuit comprises a resonant circuit provided with a transmitting coil, and the first control module and the second control module are electrically connected to the resonant circuit respectively;

[0035] The first control module is used to obtain charging parameters and calculate the charging parameters according to the difference between the charging parameters and the parameter benchmark.

[0036] Sending a phase reference to the second control module, wherein during continuous energy transmission, the phase reference is within a phase adjustable interval, the phase adjustable interval is always greater than or equal to an adjustable threshold value A, 0≤adjustable threshold value A<90°, or the phase adjustable interval is always less than or equal to an adjustable threshold value B, -90°<adjustable threshold value B≤0;

[0037] The second control module is used to collect the phase difference of the resonant circuit and output an operating frequency signal according to the phase difference and the phase reference difference. The frequency generation module is used to adjust the current of the resonant circuit according to the operating frequency signal.

[0038] Furthermore, in some embodiments of the present invention, the first control module presets the phase reference adjustable interval, and the first control module is used to determine whether the target phase reference is within the phase reference adjustable interval. If so, the target phase reference is used as the phase reference; if not, a preset phase difference corresponding to the target phase reference is used as the phase reference, and the preset phase difference is within the phase reference adjustable interval.

[0039] Furthermore, in some embodiments of the present invention, the second control module includes a phase acquisition module, and the phase acquisition module acquires a phase difference between the current of the transmitting coil and the voltage at the resonant tank port as the phase difference.

[0040] The beneficial effects of the present invention include:

[0041] In the present invention, the first control module calculates the target phase reference according to the difference between the charging parameter and the parameter reference. The first control module determines whether the target phase reference is within the adjustable range of the phase reference. If so, the target phase reference is output as the phase reference. If not, the preset phase difference corresponding to the target phase reference is output as the phase reference. The preset phase difference is within the adjustable range of the phase reference. The second control module calculates the operating frequency according to the difference between the phase difference and the phase reference, and then adjusts the current of the resonant circuit according to the operating frequency. The transmitting circuit always operates in the inductive region or the capacitive region, and the current changes with the transmitting frequency in a single manner, thereby solving the technical problem of cross-region operation of the circuit caused by the resonant frequency drift, and then the collapse of the feedback regulation mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0043] Figure 1 It is a schematic diagram of the resonant circuit impedance and current changing with frequency.

[0044] Figure 2 It is a flow chart of the control method of the present invention.

[0045] Figure 3 It is a schematic diagram of a transmitting circuit including phase control of the present invention.

[0046] Description of reference numerals:

[0047] 1-inverter; 2-resonant circuit; 3-transmitting coil; 4-current sampling circuit; 5-current controller; 6-phase acquisition module; 7-phase controller; 8-frequency generation module. DETAILED DESCRIPTION

[0048] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the detailed description of the present invention below, some specific details are described in detail. It is possible for a person skilled in the art to fully understand the present invention without the description of these details. In order to avoid confusing the essence of the present invention, known methods, processes, flows, components and circuits are not described in detail.

[0049] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0050] Unless the context clearly requires otherwise, the words "include", "including" and similar words throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, the meaning is "including but not limited to".

[0051] Figure 1 It is a schematic diagram of the resonant circuit impedance and current changing with the resonant frequency. Figure 2 It is a flow chart of the control method of the present invention. Figure 3 It is a schematic diagram of a transmitting circuit including phase control of the present invention.

[0052] like Figure 1 , the frequency normalization base is the resonant frequency, the normalized impedance is the impedance at the resonant frequency point, and the normalized current is the coil current at the resonant frequency point. When the transmitting frequency (current operating frequency) of the resonant circuit is less than the resonant frequency point, the impedance is capacitive and the resonant circuit works in the capacitive region; when the transmitting frequency (current operating frequency) of the resonant circuit is greater than the resonant frequency, the resonant circuit works in the inductive region; when it is equal to the resonant frequency, the impedance is minimum and the current is maximum. Figure 1 The corresponding resonant circuit has a quality factor Q greater than 200. Depending on the technical level, the resonant circuit quality factor can be designed to be around 300. The impedance of the resonant circuit changes steeply with the resonant frequency, and the current changes dramatically with the resonant frequency. When the deviation between the transmitting frequency and the resonant frequency is around 1%, the current will drop back to around 20% of the maximum current value. In addition, the effective transmitting frequency range can only be in a very narrow area near the resonant frequency point. Beyond the range, the current regulation ability is basically lost.

[0053] Combination Figure 1-3 The present invention provides a frequency modulation feedback control method for a transmitting circuit and a wireless energy transmission device. The energy transmission device can be used as an external programmable charger to charge an implantable medical device in the body. The transmitting circuit includes a resonant circuit 2, and the resonant circuit 2 is provided with a transmitting coil 3. The quality factor Q of the resonant circuit 2 is greater than 200. The phase difference between the transmitting coil current and the resonant circuit port voltage is collected by a phase acquisition module 6. The phase difference of the coil current lagging behind the port voltage is set to be positive. At this time, the resonant circuit 2 works in the inductive region, and the current of the transmitting coil 3 decreases as the phase difference increases; the phase difference of the coil current leading the port voltage is set to be negative. At this time, the resonant circuit 2 works in the capacitive region, and the current of the transmitting coil 3 increases as the phase difference increases; when the phase difference is 0, the resonant circuit 2 works at the resonant frequency point, and the current of the transmitting coil 3 is the maximum at the resonant frequency point, and decreases to both sides of the capacitive region and the inductive region.

[0054] Control methods include:

[0055] S10 obtains the current charging parameter and calculates the target phase reference according to the difference between the charging parameter and the parameter reference.

[0056] In an embodiment of the present invention, the charging parameter includes the current of the transmitting coil 3, and the parameter reference includes the current reference. Obtaining the current charging parameter and calculating the target phase reference according to the difference with the parameter reference includes: obtaining the current current of the transmitting coil 3 and calculating the target phase reference according to the difference with the current reference. Specifically, the current of the transmitting coil 3 can be collected by the current sampling circuit 4, and then the current controller 5 calculates the target phase reference according to the difference between the current of the transmitting coil 3 and the current reference. The current reference can be given by the upper controller, and the upper controller obtains the receiving power, charging current or charging voltage of the power controller of the wireless energy receiving end as the receiving parameter, and calculates the current reference according to the difference between the receiving parameter and the predetermined parameter. The predetermined parameter can be the predetermined power, predetermined charging current, and voltage of the receiving end. Taking the power controller of the receiving end as an example, a feasible working method is: the receiving parameter includes the receiving power, the predetermined parameter includes the predetermined power, the upper controller regularly reads the receiving power of the receiving end, and calculates the current value of the resonant circuit of the next cycle according to the difference between the receiving power and the predetermined power, and uses the calculated current value as the current reference. The upper controller is arranged outside the body, and can be integrated into an external programmable charger (i.e., an energy transmission device), or arranged in other external devices that can communicate with the external programmable charger. In some other implementations, the current regulator and voltage controller at the receiving end can also be used as the upper controller, and then the calculated current reference is sent to the current controller 5.

[0057] In the present invention, the target phase reference is calculated by the current controller 5 of the transmitting coil, and can also be given by other controllers of the transmitting end and the receiving end according to the charging parameters and parameter references. The controller of the transmitting end includes but is not limited to: (1) a power controller of the transmitting power loop, the charging parameter is AC power, and the parameter reference is an AC power reference calculated based on the difference between the receiving power of the implanted medical device and the predetermined power; (2) a current regulator of the DC side current loop, the charging parameter is the DC input current of the inverter, and the parameter reference is a DC current reference calculated based on the difference between the receiving power of the implanted medical device and the predetermined power; (3) a power controller of the power loop on the DC side, the charging parameter is the product of the input DC current and the DC voltage, and the parameter reference is a DC power reference calculated based on the difference between the receiving power of the implanted medical device and the predetermined power. The controller of the receiving end includes but is not limited to the controllers in the power loop, charging voltage, and charging current loop of the implanted medical device.

[0058] S20 determines whether the target phase reference is within the phase reference adjustable interval;

[0059] S21: if yes, use the target phase reference as the phase reference;

[0060] If not, then use the preset phase difference as the phase reference in S22.

[0061] Specifically, judging whether the target phase reference is within the adjustable interval of the phase reference includes: when the adjustable interval of the phase reference is greater than or equal to the adjustable threshold value A, where 0≤adjustable threshold value A<90°, judging whether the target phase reference is greater than or equal to the adjustable threshold value A, or, when the adjustable interval of the phase reference is less than or equal to the adjustable threshold value B, where -90°<adjustable threshold value B≤0, judging whether the target phase reference is less than or equal to the adjustable threshold value B. In the present invention, whether the target phase reference is within the adjustable interval of the phase reference is used as a determination procedure for the target phase reference to judge whether the target phase reference is a valid value, and if the limiting conditions are met, it is determined to be a valid value, and if the limiting conditions are not met, it is replaced with a preset phase difference.

[0062] It should be noted that the target phase reference is calculated based on the difference between the current of the current transmitting coil and the current reference. The calculated value is variable and may be positive or negative due to changes in the charging environment, distance, angle, and component parameters. The preset phase difference is a preset value corresponding to the calculated target phase reference.

[0063] If 0≤target phase reference<adjustable threshold A or adjustable threshold B<target phase reference≤0, the preset phase difference is used as the phase reference. When the target phase reference is greater than 0, the preset phase difference A is used as the phase reference, and the adjustable threshold A≤preset phase difference A<90°; when the target phase reference is less than 0, the preset phase difference B is used as the phase reference, and the adjustable threshold B≤preset phase difference B<-90°. Preferably, 5≤adjustable threshold A<20°, -20°<adjustable threshold B≤-5°, when the adjustable threshold A takes a value of 10° and the adjustable threshold B takes a value of -10°, in a complete charging process, the adjustable threshold A is always selected to be 10° or the adjustable threshold B is always selected to be -10°, thereby leaving an adjustment margin to ensure charging safety. In the present invention, the adjustable threshold A and the adjustable threshold B can be set according to design requirements.

[0064] During continuous energy transmission or a complete charging process, when judging whether the target phase reference is within the adjustable range of the phase reference, only one of the two adjustable range conditions is selected to be executed, thereby ensuring that the final phase reference is always greater than or equal to 0 degrees or less than or equal to 0 degrees, and the resonant circuit 2 is always adjusted according to the phase reference to operate in the inductive zone, the capacitive zone or the resonant point, and the resonant circuit 2 does not operate across regions.

[0065] S30 collects the phase difference of the resonant circuit 2 and calculates the operating frequency according to the difference between the phase difference and the phase reference.

[0066] Specifically, the phase acquisition module 6 is used to collect the phase difference between the current of the transmitting coil 3 and the voltage at the port of the resonant circuit 2. The phase of the current of the transmitting coil 3 lagging behind the port voltage is positive, and the resonant circuit 2 works in the inductive region; the phase of the current leading the port voltage is negative, and the resonant circuit 2 works in the capacitive region; when the phase is just 0 degrees, the circuit works at the resonance point. Regardless of whether the resonant circuit 2 is in the capacitive or inductive region, the phase increases with the increase of the frequency, and the actual phase of the current resonant circuit 2 is controlled to the phase reference. The specific principle is to judge the relationship between the current circuit phase and the phase reference. If it is greater than the reference, the frequency is reduced; if it is less than the reference, the frequency needs to be increased. For the resonant circuit 2 with a high quality factor, the coil current size is controlled by controlling the phase difference to avoid the inversion of the feedback logic and the collapse of the adjustment mechanism. In the present invention, the transmitting circuit includes a phase controller 7, and the phase controller 7 calculates the operating frequency according to the phase difference and the phase reference.

[0067] S40 adjusts the current of the resonant circuit 2 according to the operating frequency, and executes S10 again after a preset time interval.

[0068] The transmitting circuit includes a frequency generating module 8, the phase controller 7 sends an operating frequency signal to the frequency generating module 8, the frequency generating module 8 outputs the operating frequency, and the transmitting circuit adjusts the current and power of the resonant circuit 2 according to the operating frequency, thereby adjusting the transmitting frequency to the operating frequency.

[0069] The present invention ensures that the resonant circuit 2 does not operate across regions during continuous energy transmission or a complete charging process. The operating frequency is calculated based on the difference between the phase difference and the phase reference, and then the current and power of the resonant circuit 2 are adjusted based on the operating frequency. When the current of the transmitting coil 3 changes, the phase difference changes accordingly, so that the actual phase of the resonant circuit 2 is adjusted to the phase reference. Even if the resonant frequency drifts, the working mechanism of the phase output control remains unchanged, and the operating frequency will be adjusted adaptively without being affected by the resonant frequency drift.

[0070] Example: The resonant circuit 2 is adjusted to work in the inductive area or the resonance point. The current of the transmitting coil 3 decreases as the phase difference increases in the inductive area. The phase difference of the current circuit is smaller than the phase reference. According to "when the phase difference is greater than the phase reference, the transmitting frequency is reduced, and when the phase difference is less than the phase reference, the transmitting frequency is increased", the phase control module calculates the operating frequency corresponding to the phase reference, and adjusts the current and power of the resonant circuit 2 based on the operating frequency. The phase difference and the transmitting frequency change accordingly, thereby adjusting the actual phase difference to the phase reference.

[0071] Compared with the existing closed-loop control scheme that directly controls the frequency, the data of the working frequency of the present invention is provided by the phase controller 7, rather than obtained by the current or power loop. According to the adjustable interval limit of the phase reference, the resonant circuit always works in the inductive zone and the capacitive zone, and the current changes with the transmission frequency in a single manner. Then, the difference between the phase difference of the resonant circuit 2 and the phase reference is detected in real time, and the working frequency is output. The current and power of the resonant circuit 2 are adjusted according to the working frequency, so that the frequency modulation feedback control scheme of the high Q value resonant circuit 2 is feasible, and the problem of feedback control mechanism collapse caused by the resonant frequency drift is avoided. Compared with the existing DC / DC control circuit adjustment scheme, the present invention reduces the device withstand voltage and design complexity, and can even remove the DC / DC circuit, which not only reduces the area and cost, but also improves the system working efficiency, and reduces the external programmable charger power required for a single wireless charging and the battery capacity requirements. In the present invention, the calculation of the phase reference can be performed once at a preset time length, and the calculation and adjustment of the working frequency output can be performed once at a preset time length b, wherein the a time length is much greater than the b time length, that is, the calculation of the phase reference can be completed once, and the calculation of the working frequency and the transmission frequency adjustment can be performed multiple times.

[0072] The present invention provides an energy transmission device, which is used as an external programmable charger. Figure 3 The energy transmission device includes a first control module, a second control module, a frequency generation module 8 and a transmitting circuit, wherein the transmitting circuit includes an inverter 1 and a resonant circuit 2 with a quality factor greater than 200, and the resonant circuit 2 includes a capacitor, a resistor, and a transmitting coil 3. The first control module, the second control module and the frequency generation module 8 are electrically connected to the transmitting circuit respectively. In the present invention, the transmitting circuit can use the above control method to adjust the current and power of the resonant circuit 2 by calculating the phase reference.

[0073] The first control module is used to obtain the charging parameters and send the phase reference to the second control module according to the difference between the charging parameters and the parameter reference. The upper controller obtains the receiving power, charging current or charging voltage of the receiving end power controller as the receiving parameter, and calculates the parameter reference according to the difference between the receiving parameter and the predetermined parameter. In this embodiment, the charging parameter includes the current of the transmitting coil, the parameter reference includes the current reference, the receiving parameter includes the receiving power, and the predetermined parameter includes the predetermined power. The upper controller periodically reads the receiving power of the receiving end, calculates the current value of the resonant circuit in the next period according to the difference between the receiving power and the predetermined power, and uses the calculated current value as the current reference.

[0074] The first control module includes a current sampling circuit 4 and a current controller 5. The current sampling circuit 4 is electrically connected to the resonant circuit 2. The current sampling circuit 4 is used to collect the current of the transmitting coil 3, which can also be the current of the resonant circuit 2. The current controller 5 can receive the current reference sent by the upper controller, and calculate the target phase reference according to the current of the transmitting coil 3 and the current reference. The current controller 5 presets an adjustable phase reference interval to determine whether the target phase reference is within the adjustable phase interval. If so, the target phase reference is used as the phase reference. If not, a preset phase difference is output as the phase reference. The preset phase difference is within the adjustable phase reference interval, so that the output phase reference is always within the preset phase reference adjustable interval.

[0075] Determining whether the target phase reference is within the adjustable interval of the phase reference includes: when the adjustable interval of the phase reference is greater than or equal to the adjustable threshold value A, where 0≤adjustable threshold value A<90°, determining whether the target phase reference is greater than or equal to the adjustable threshold value A, or, when the adjustable interval of the phase reference is less than or equal to the adjustable threshold value B, where -90°<adjustable threshold value B≤0, determining whether the target phase reference is less than or equal to the adjustable threshold value B. In the present invention, whether the target phase reference is within the adjustable interval of the phase reference is used as a determination procedure for the target phase reference to determine whether the target phase reference is a valid value, and if the limiting conditions are met, it is determined to be a valid value, and if the limiting conditions are not met, it is replaced with a preset phase difference.

[0076] In some other embodiments, the first control module may also use other controllers to calculate the target phase reference, including but not limited to the power controller of the transmitting power loop of the transmitting end, the current regulator of the DC side current loop, and the power controller of the DC side power loop, and the charging parameters are the AC side power of inverter 1, the DC side current of inverter 1, and the DC side power of inverter 1. The first control module may also include controllers of the implantable medical device (receiving end) power loop, the charging voltage loop, and the charging current loop, and the charging parameters are the receiving power, the charging voltage, and the charging current.

[0077] The second control module includes a phase acquisition module 6 and a phase controller 7. The phase acquisition module 6 is used to acquire the phase difference of the resonant circuit 2. Specifically, the phase difference between the current of the transmitting coil 3 and the voltage of the port of the resonant circuit 2 is acquired. The port of the resonant circuit 2 is the port connected to the inverter 1. The phase controller 7 is electrically connected to the phase acquisition module 6 and the current controller 5. The phase controller 7 receives the phase reference sent by the current controller 5, calculates the working frequency according to the difference between the phase difference and the phase reference, and sends the working frequency signal to the frequency generation module 8. The frequency generation module 8 outputs the working frequency, controls the inverter 1 to adjust the current of the resonant circuit 2 according to the working frequency, and when the target phase reference is within the adjustable phase interval, adjusts the phase difference to be equal to the phase reference, so that the transmitting frequency of the resonant circuit 2 is equal to the working frequency. When the target phase reference is not within the adjustable phase reference interval, the target phase reference is a preset phase difference, and the phase difference of the resonant circuit 2 is adjusted to be equal to the preset phase difference. At this time, the adjusted working frequency is not completely consistent with the resonant frequency, and an adjustment margin is reserved.

[0078] In some other embodiments, the temperature of an implantable medical device in the body can be collected during charging. If the temperature reaches a preset temperature threshold, the value of the adjustable threshold A is increased or the value of the adjustable threshold B is decreased, and the target phase reference range that is not in the adjustable phase reference interval becomes larger, so that the number of situations where the operating frequency is not completely consistent with the resonant frequency increases, thereby reducing the charging power and reducing the heat generation of the implantable medical device in the body.

[0079] In the present invention, the phase of the current of the transmitting coil 3 lagging behind the port voltage is set to be positive, and the circuit works in the inductive region; the phase of the current leading the port voltage is set to be negative, and the circuit works in the capacitive region; when the phase is exactly 0 degrees, the circuit works at the resonance point. Whether in the capacitive or inductive region, the phase increases with the increase of frequency (considering the positive and negative signs). The current controller 5 sets an adjustable phase reference interval, and the phase reference output by the current controller 5 is always within the adjustable phase interval. During the continuous charging process, the adjustable phase reference interval is always set to the adjustable threshold A or the adjustable threshold B, 0≤adjustable threshold A<90°, -90°<adjustable threshold B≤0. The phase controller 7 then calculates the operating frequency based on the phase difference and phase reference of the resonant circuit, so that the resonant circuit 2 always operates in the inductive or capacitive region, and the current changes with the transmission frequency in a single manner. The current and power of the resonant circuit 2 are adjusted according to the operating frequency. Even if the drift of the component parameters of the resonant circuit causes the resonant frequency to drift, the working mechanism of the first control module and the second control module remains unchanged, and the operating frequency will be adaptively adjusted to be regulated to the given phase reference, which is not affected by the resonant frequency drift.

[0080] In the present invention, the current controller 5 and the phase controller 7 can be implemented by independent analog chips or circuits, or by digital controllers, including single-chip microcomputers, DSPs (Digital signal processors), etc. The frequency generation module 8 can be generated by pulse width modulation PWM (Pulse Width Modulation) inside the digital controller or by modules such as the Timer of the digital controller, or by independent analog circuits, including voltage-controlled oscillators, RC oscillators, etc. The phase acquisition module 6 can be implemented by comparing the zero-crossing points of the voltage and current, or by waveform sampling and fundamental wave analysis by the controller.

[0081] In the present invention, the phase controller 7 includes but is not limited to a PI controller, a PID controller, and a PR controller. The resonant circuit 2 in the transmitting circuit only shows an LC circuit, and other circuits include but are not limited to LLC, LCC, etc. The input of the inverter can be provided by a DC / DC front-stage circuit, or directly by a total input source of the system, which usually depends on whether the total input voltage of the system is sufficient to provide the required coil current. In addition to full-bridge inverters, inverters can also use half-bridge inverters, CLASS-E inverters, CLASS-AB inverters, etc. The above examples only show the use of the invention in a frequency modulation feedback method. In addition, it can also be used in a voltage regulation / frequency modulation hybrid control method, and the specific strategies of frequency modulation and voltage regulation control are not limited.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A frequency modulation feedback control method for a transmitting circuit, characterized in that: The transmitting circuit includes a resonant circuit provided with a transmitting coil, including: S10 obtains the current charging parameter and calculates the target phase reference according to the difference between the charging parameter and the parameter reference; S20 determines whether the target phase reference is within the phase reference adjustable interval; S21: If yes, use the target phase reference as the phase reference; If no, S22 uses the preset phase difference corresponding to the target phase reference as the phase reference, wherein the preset phase difference is within the adjustable range of the phase reference; S30 collects the phase difference of the resonant circuit and calculates the operating frequency according to the difference between the phase difference and the phase reference; S40 adjusts the current of the resonant circuit according to the operating frequency, and executes S10 again after a preset time interval.

2. The transmission circuit frequency modulation feedback control method according to claim 1, characterized in that: The charging parameter includes the current of the transmitting coil, and the parameter reference includes the current reference; The obtaining of the current charging parameter and calculating the target phase reference according to the difference with the parameter reference includes: The current of the current transmitting coil is obtained and the target phase reference is calculated according to the difference between the current and the current reference.

3. The transmission circuit frequency modulation feedback control method according to claim 2, characterized in that: The current of the current transmitting coil is obtained and the target phase reference is calculated according to the difference between the current and the current reference, and also includes: Obtaining receiving parameters of the wireless energy receiving end; The current reference is calculated according to a difference between the received parameter and a predetermined parameter.

4. The transmission circuit frequency modulation feedback control method according to claim 3, characterized in that: The receiving parameter includes receiving power, and the predetermined parameter includes predetermined power; Calculating the current reference according to the difference between the received parameter and the predetermined parameter includes: Regularly reading the received power of the wireless energy receiving end; Calculating the current value of the resonant circuit in the next cycle according to the difference between the received power and the predetermined power; The calculated current value is used as the current reference.

5. The transmission circuit frequency modulation feedback control method according to claim 1, characterized in that: Determining whether the target phase reference is within the phase reference adjustable interval includes: Determine whether the target phase reference is greater than or equal to an adjustable threshold value A, 0≤adjustable threshold value A<90°; or It is determined whether the target phase reference is less than or equal to an adjustable threshold value B, where -90°<adjustable threshold value B≤0.

6. The transmission circuit frequency modulation feedback control method according to claim 5, characterized in that: Determining whether the target phase reference is greater than or equal to an adjustable threshold A includes: If yes, taking the target phase reference as the phase reference; If not, the preset phase difference A corresponding to the target phase reference is used as the phase reference, and the adjustable threshold value A≤preset phase difference A<90°; Determining whether the target phase reference is less than or equal to an adjustable threshold B includes: If yes, taking the target phase reference as the phase reference; If not, the preset phase difference B corresponding to the target phase reference is used as the phase, and the adjustable threshold B≤preset phase difference B<-90°.

7. The transmission circuit frequency modulation feedback control method according to claim 1, characterized in that: Collecting the phase difference of the resonant circuit includes: The phase difference between the current of the transmitting coil and the voltage at the resonant tank port is collected.

8. A wireless energy transmission device, characterized in that: It includes a first control module, a second control module, a frequency generation module and a transmitting circuit, wherein the transmitting circuit includes a resonant circuit provided with a transmitting coil, and the first control module and the second control module are electrically connected to the resonant circuit respectively; The first control module is used to obtain charging parameters, and send a phase reference to the second control module according to the difference between the charging parameters and the parameter reference. During continuous energy transmission, the phase reference is within the phase adjustable interval, the phase adjustable interval is always greater than or equal to the adjustable threshold A, 0≤adjustable threshold A<90°, or, the phase adjustable interval is always less than or equal to the adjustable threshold B, -90°<adjustable threshold B≤0; The second control module is used to collect the phase difference of the resonant circuit and output an operating frequency signal according to the phase difference and the phase reference difference. The frequency generation module is used to adjust the current of the resonant circuit according to the operating frequency signal.

9. The wireless energy transmission device according to claim 8, characterized in that: The first control module presets the phase reference adjustable interval, and the first control module is used to determine whether the target phase reference is within the phase reference adjustable interval. If so, the target phase reference is used as the phase reference; if not, a preset phase difference corresponding to the target phase reference is used as the phase reference, and the preset phase difference is within the phase reference adjustable interval.

10. The wireless energy transmission device according to claim 8, characterized in that: The second control module includes a phase acquisition module, and the phase acquisition module acquires a phase difference between the current of the transmitting coil and the voltage at the resonant circuit port as the phase difference.

Images