Circuit parameter determination method of ultrasonic wireless power transmission system and electronic equipment

Abstract

The invention provides a circuit parameter determination method of an ultrasonic wireless electric energy transmission system and electronic equipment, and belongs to the technical field of ultrasonic wireless transmission, the ultrasonic wireless electric energy transmission system comprises an energy transmission module and a compensation circuit, the energy transmission module comprises a transmitting transducer, a transmission medium and a receiving transducer, the circuit parameter determination method comprises the following steps: acquiring a characteristic admittance curve of a target transducer, wherein the target transducer comprises a transmitting transducer and / or a receiving transducer; based on the characteristic admittance curve and a preset first relation model, parameter values of all elements included in the first equivalent circuit are obtained; and determining the parameter value of each element included in the compensation circuit based on the parameter value of each element included in the first equivalent circuit and a preset second relation model. According to the method provided by the invention, systematicness of reactive power, transmission power and output voltage stability of the ultrasonic wireless power transmission system can be collaboratively optimized.

Description

Technical Field

[0001] This application belongs to the field of ultrasonic radio transmission technology, specifically relating to a method for determining circuit parameters and an electronic device for ultrasonic wireless power transmission systems. Background Technology

[0002] Ultrasonic Wireless Power Transfer (UWPT) systems, with their advantages of wide media adaptability, high biocompatibility, and strong penetration, hold significant value in implantable medical devices, underwater applications, and specialized industrial power supply. However, the development of this technology remains limited by insufficient accuracy in system-level circuit models and the lack of systematic synergistic optimization among reactive power, transmitted power, and output voltage stability—key challenges that hinder its advancement. Summary of the Invention

[0003] In view of the above problems, embodiments of this application provide a method and electronic device for determining circuit parameters of an ultrasonic wireless power transmission system, so as to overcome the above problems or at least partially solve the above problems.

[0004] A first aspect of this application provides a method for determining circuit parameters of an ultrasonic wireless power transmission system. The ultrasonic wireless power transmission system includes an energy transmission module and a compensation circuit. The energy transmission module includes a transmitting transducer, a transmission medium, and a receiving transducer. The method includes: Obtain the characteristic admittance curve of the target transducer, which includes the transmitting transducer and / or the receiving transducer; based on the characteristic admittance curve and a preset first relationship model, obtain the parameter values ​​of each component in the first equivalent circuit, where the first equivalent circuit is the equivalent circuit corresponding to the energy transmission module, and the first relationship model is determined based on the first equivalent circuit. The first relationship model characterizes the correspondence between the admittance and resonant frequency of the ultrasonic wireless power transmission system and the parameters of each component in the first equivalent circuit; based on the parameter values ​​of each component in the first equivalent circuit and a preset second relationship model, determine the parameter values ​​of each component in the compensation circuit, where the second relationship model is determined based on the second equivalent circuit corresponding to the energy transmission module and the compensation circuit, and the second relationship model characterizes the correspondence between the impedance of the ultrasonic wireless power transmission system and the parameters of each component in the second equivalent circuit.

[0005] In some embodiments, the target transducer is the transmitting transducer, the compensation circuit is connected to the transmitting transducer, the first equivalent circuit includes a primary-side equivalent circuit, the primary-side equivalent circuit includes a first equivalent series resistance, a first equivalent series inductance, a first equivalent series capacitance, and a first equivalent parallel capacitance, the first terminal of the first equivalent series resistance is connected to the first terminal of the first equivalent parallel capacitance and the positive terminal of the voltage source, the second terminal of the first equivalent series resistance is connected to the first terminal of the first equivalent series inductance, the second terminal of the first equivalent series inductance is connected to the first terminal of the first equivalent series capacitance, the second terminal of the first equivalent series capacitance is connected to the second terminal of the first equivalent parallel capacitance and the negative terminal of the voltage source, the voltage source is configured to input voltage to the energy transmission module; the acquisition of the target transducer The characteristic admittance curve of the transducer includes: acquiring input admittance curves of the transmitting transducer under multiple different loads, and taking the input admittance curve under at least one load as the characteristic admittance curve, wherein the input admittance curve is the relationship curve between the frequency and input admittance of the ultrasonic wireless power transmission system; based on the characteristic admittance curve and a preset first relationship model, obtaining the parameter values ​​of each component included in the first equivalent circuit, including: determining the resonant frequency of the ultrasonic wireless power transmission system based on the input admittance curve under at least one load; and performing curve fitting on the first relationship model based on the resonant frequency to obtain the fitting result of the input admittance curve matching, wherein the fitting result includes the parameter values ​​of the first equivalent series resistance, the first equivalent series inductance, the first equivalent series capacitance, and the first equivalent parallel capacitance.

[0006] In some embodiments, the compensation circuit includes a first compensation capacitor and a first compensation inductor. A first terminal of the first compensation inductor is connected to the positive terminal of the voltage source, and a second terminal of the first compensation inductor is connected to both the first terminal of the first equivalent parallel capacitor and the first terminal of the first equivalent parallel capacitor. The second terminal of the first compensation capacitor is connected to the negative terminal of the voltage source. Based on the parameter values ​​of each component included in the first equivalent circuit and a preset second relationship model, the parameter values ​​of each component included in the compensation circuit are determined, including: obtaining the input impedance, input power, and input voltage of the ultrasonic wireless power transmission system; wherein the imaginary part of the input impedance is zero; substituting the parameter values ​​of the input impedance, the input power, the first equivalent series resistance, the first equivalent series inductor, the first equivalent series capacitor, and the first equivalent parallel capacitor into the second relationship model to obtain the parameter values ​​of the first compensation capacitor and the first compensation inductor.

[0007] In some embodiments, the target transducer is the receiving transducer, the compensation circuit is connected to the receiving transducer, the first equivalent circuit includes a secondary equivalent circuit, the secondary equivalent circuit includes a second equivalent series resistance, a second equivalent series inductance, a second equivalent series capacitance, and a second equivalent parallel capacitance, the first terminal of the second equivalent series resistance is connected to the positive terminal of the equivalent voltage source, the second terminal of the second equivalent series resistance is connected to the first terminal of the second equivalent series inductance, the second terminal of the second equivalent series inductance is connected to the first terminal of the second equivalent series capacitance, the second terminal of the second equivalent series capacitance is connected to the first terminal of the second equivalent parallel capacitance and the first terminal of the load, and the second terminal of the second equivalent parallel capacitance is connected to the negative terminal of the equivalent voltage source and the second terminal of the load; the acquisition of the target transducer. The characteristic admittance curve of the transducer includes: acquiring the output admittance curves of the transmitting transducer under multiple different loads, and taking the output admittance curve under at least one load as the characteristic admittance curve, wherein the output admittance curve is the frequency-admittance relationship curve of the ultrasonic wireless power transmission system; based on the characteristic admittance curve and a preset first relationship model, obtaining the parameter values ​​of each component included in the first equivalent circuit, including: determining the resonant frequency of the ultrasonic wireless power transmission system based on the output admittance curve under at least one load; and performing curve fitting on the first relationship model based on the resonant frequency to obtain the fitting result of the output admittance curve matching, wherein the fitting result includes the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, the second equivalent series capacitance, and the second equivalent parallel capacitance.

[0008] In some embodiments, the compensation circuit includes a second compensation capacitor and a second compensation inductor. A first terminal of the second compensation inductor is connected to a first terminal of the second compensation capacitor and a first terminal of the second equivalent parallel capacitor, respectively. A second terminal of the second compensation inductor is connected to a first terminal of the load, and a second terminal of the second compensation capacitor is connected to a second terminal of the load and a second terminal of the second equivalent parallel capacitor, respectively. Based on the parameter values ​​of each component included in the first equivalent circuit and a preset second relationship model, the parameter values ​​of each component included in the compensation circuit are determined, including: obtaining the no-load voltage of the energy transmission module, and determining the parameter values ​​of the equivalent voltage source based on the no-load voltage and the parameter values ​​of each component included in the first equivalent circuit; obtaining the resistance parameter value of the load, and substituting the resistance parameter value, the parameter value of the equivalent voltage source, the parameter values ​​of the second equivalent series resistance, the second equivalent series inductor, the second equivalent series capacitor, and the second equivalent parallel capacitor into the second relationship model to obtain the parameter values ​​of the second compensation capacitor and the second compensation inductor.

[0009] In some embodiments, obtaining the no-load voltage of the energy transmission module and determining the parameter values ​​of the equivalent voltage source based on the no-load voltage and the parameter values ​​of each component included in the first equivalent circuit includes: obtaining the complex impedance of the first equivalent circuit based on the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, and the second equivalent series capacitance; obtaining the equivalent impedance of the first equivalent circuit based on the complex impedance and the parameter values ​​of the second equivalent parallel capacitance; and determining the parameter values ​​of the equivalent voltage source based on the complex impedance, the equivalent impedance, and the no-load voltage.

[0010] In some embodiments, the target transducer includes the transmitting transducer and the receiving transducer, the compensation circuit is connected to the voltage source and the load of the energy transmission module respectively, the first relational model includes a first sub-model, a second sub-model and a third sub-model, the first equivalent circuit includes a two-port equivalent circuit, the two-port equivalent circuit includes a first sub-circuit, a second sub-circuit and a third sub-circuit, the first terminal of the first sub-circuit is connected to the positive terminal of the voltage source and the first terminal of the third sub-circuit respectively, the second terminal of the third sub-circuit is connected to the first terminal of the second sub-circuit and the first terminal of the load respectively, and the second terminal of the second sub-circuit is connected to the first terminal of the first sub-circuit, the negative terminal of the voltage source and the second terminal of the load respectively; obtaining the characteristic admittance curve of the target transducer includes: obtaining the input admittance curve of the receiving transducer when short-circuited and the output admittance curve of the transmitting transducer when short-circuited, and using the input admittance curve and the output admittance curve as the characteristic admittance curve; the method further includes: obtaining the on-state of the receiving transducer The input impedance curve is obtained; based on the characteristic admittance curve and a preset first relationship model, the parameter values ​​of each component in the first equivalent circuit are obtained, including: acquiring the input admittance curve, the output admittance curve, and the input impedance curve to obtain the first mutual admittance parameter and the second mutual admittance parameter of the target transducer; adding the input admittance curve to the first mutual admittance parameter to obtain the first admittance characteristic curve of the first sub-circuit, and obtaining the parameter values ​​of each component in the first sub-circuit based on the first admittance characteristic curve and the first sub-model; taking the negative of the first mutual admittance parameter as the second admittance characteristic curve of the second sub-circuit, and obtaining the parameter values ​​of each component in the second sub-circuit based on the second admittance characteristic curve and the second sub-model; adding the output admittance curve to the second mutual admittance parameter to obtain the third admittance characteristic curve of the third sub-circuit, and obtaining the parameter values ​​of each component in the third sub-circuit based on the third admittance characteristic curve and the third sub-model.

[0011] In some embodiments, the compensation circuit includes a third compensation inductor and a third compensation capacitor. The first terminal of the third compensation inductor is connected to the positive terminal of the voltage source, the second terminal of the third compensation inductor is connected to the first terminal of the third compensation capacitor and the first terminal of the first equivalent circuit, and the second terminal of the third compensation capacitor is connected to the negative terminal of the voltage source. Based on the parameter values ​​of each component included in the first equivalent circuit and a preset second relationship model, the parameter values ​​of each component included in the compensation circuit are determined, including: obtaining the input impedance, input power, and input voltage of the energy transmission module; wherein the imaginary part of the input impedance is zero; substituting the input impedance, the input power, and the parameter values ​​of each component included in the first sub-circuit, the second sub-circuit, and the third sub-circuit into the second relationship model to obtain the parameter values ​​of the third compensation capacitor and the third compensation inductor.

[0012] In some embodiments, the first sub-circuit includes a third equivalent series resistance, a third equivalent series inductance, a third equivalent series capacitance, and a third equivalent parallel capacitance. The first terminal of the third equivalent series resistance and the first terminal of the third equivalent parallel capacitance serve as the first terminal of the first sub-circuit, and the second terminal of the third equivalent series capacitance and the second terminal of the third equivalent parallel capacitance serve as the second terminal of the first sub-circuit. The third equivalent series inductance is connected between the second terminal of the third equivalent series resistance and the first terminal of the third equivalent series capacitance. The second sub-circuit includes a fourth equivalent series resistance, a fourth equivalent series inductance, a fourth equivalent series capacitance, and a fourth equivalent parallel capacitance. The first terminal of the fourth equivalent series resistance and the first terminal of the fourth equivalent parallel capacitance serve as the second sub-circuit. The first terminal, the second terminal of the fourth equivalent series capacitor and the second terminal of the fourth equivalent parallel capacitor serve as the second terminal of the second sub-circuit, and the fourth equivalent series inductor is connected between the second terminal of the fourth equivalent series resistor and the first terminal of the fourth equivalent series capacitor; the third sub-circuit includes a fifth equivalent series resistor, a fifth equivalent series inductor, a fifth equivalent series capacitor and a fifth equivalent parallel capacitor, the first terminal of the fifth equivalent series resistor and the first terminal of the fifth equivalent parallel capacitor serve as the first terminal of the third sub-circuit, the second terminal of the fifth equivalent series capacitor and the second terminal of the fifth equivalent parallel capacitor serve as the second terminal of the third sub-circuit, and the fifth equivalent series inductor is connected between the second terminal of the fifth equivalent series resistor and the first terminal of the fifth equivalent series capacitor.

[0013] A second aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory. When the computer program is executed by the processor, it implements the steps of the method for determining circuit parameters of the ultrasonic wireless power transmission system described in the first aspect of this application.

[0014] This embodiment provides a method for determining circuit parameters of an ultrasonic wireless power transfer system. The ultrasonic wireless power transfer system includes an energy transfer module and a compensation circuit. The energy transfer module includes a transmitting transducer, a transmission medium, and a receiving transducer. The method first obtains the characteristic admittance curve of a target transducer, which includes a transmitting transducer and / or a receiving transducer. Then, based on the characteristic admittance curve and a preset first relationship model, it obtains the parameter values ​​of each component in a first equivalent circuit. The first equivalent circuit is the equivalent circuit corresponding to the energy transfer module. The first relationship model is determined based on the first equivalent circuit. The first relationship model characterizes the admittance and resonant frequency of the ultrasonic wireless power transfer system and the parameter values ​​of each component in the first equivalent circuit. The correspondence between numbers allows for precise equivalence of the transmitting transducer, receiving transducer, and transmission medium as a whole, thereby establishing various high-precision system equivalent models. Then, based on the parameter values ​​of each component in the first equivalent circuit and the preset second relationship model, the parameter values ​​of each component in the compensation circuit are determined. Since the second relationship model is determined based on the second equivalent circuit corresponding to the energy transmission module and the compensation circuit, the second relationship model characterizes the correspondence between the impedance of the ultrasonic wireless power transmission system and the parameters of each component in the second equivalent circuit. Finally, the systemic relationship between the reactive power, transmission power, and output voltage stability of the ultrasonic wireless power transmission system can be synergistically optimized using the parameter values ​​of each component in the compensation circuit. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating the steps of a method for determining circuit parameters of an ultrasonic wireless power transmission system according to an embodiment of this application. Figure 2 This is a schematic diagram of an ultrasonic wireless power transmission system provided in an embodiment of this application; Figure 3 This is a schematic diagram of the primary-side equivalent circuit provided in the embodiments of this application; Figure 4 This is a schematic diagram of the input admittance curves of the transmitting transducers under different loads provided in the embodiments of this application; Figure 5 This is a schematic diagram of the curves showing the actual and fitted values ​​of the input admittance with a load of 10Ω as a function of frequency, provided in an embodiment of this application. Figure 6 It is aimed at Figure 5 A schematic diagram of the primary-side equivalent circuit at the provided resonant frequency; Figure 7 It is aimed at Figure 5 A schematic diagram of the compensated primary-side equivalent circuit is provided. Figure 8 This is a schematic diagram of the secondary-side equivalent circuit provided in an embodiment of this application; Figure 9 This is a schematic diagram of the curves showing the actual and fitted values ​​of the output admittance of an ultrasonic wireless power transmission system as a function of frequency, provided in an embodiment of this application. Figure 10 It is aimed at Figure 8 A simplified schematic diagram of the primary-side equivalent circuit at the provided resonant frequency; Figure 11 This is a schematic diagram of the output voltage of a UWPT system provided in an embodiment of this application; Figure 12 This is a schematic diagram of the equivalent circuit of the secondary side using parallel inductor compensation; Figure 13 It is aimed at Figure 8 A schematic diagram of the compensated secondary-side equivalent circuit is provided. Figure 14 This is a schematic diagram of the two-port equivalent circuit provided in an embodiment of this application; Figure 15 This is a schematic diagram of the voltage and current of the energy transfer section of a UWPT system provided in an embodiment of this application; Figure 16 This is a schematic diagram of the admittance and impedance curves of the UWPT system under different port conditions provided in the embodiments of this application; Figure 17 This is a schematic diagram of the theoretical and fitted values ​​of the UWPT system transfer admittance as a function of frequency, provided in the embodiments of this application. Figure 18 It is aimed at Figure 14 A schematic diagram of a two-port equivalent circuit near the resonant frequency is provided. Figure 19 It is aimed at Figure 18 A schematic diagram of the two-port equivalent circuit at the provided resonant frequency; Figure 20 This is a schematic diagram of the compensated two-port equivalent circuit provided in the embodiments of this application; Figure 21 This is a simulation circuit diagram of the primary-side equivalent circuit of the UWPT system after LC compensation provided in the embodiments of this application; Figure 22 This is a schematic diagram of the curves showing the change of the primary input impedance of the UWPT system before and after compensation with respect to the load, provided in the embodiments of this application. Figure 23This is a schematic diagram of the curves showing the change of primary-side input power of the UWPT system before and after compensation with respect to load, provided in an embodiment of this application. Figure 24 This is a schematic diagram of the curves showing the change of the driving voltage of the transmitting transducer before and after compensation with the load, provided in an embodiment of this application. Figure 25 This is a simulation circuit diagram of the two-port equivalent circuit of the UWPT system after LC compensation provided in the embodiments of this application; Figure 26 This is a schematic diagram of the curves showing the change of the secondary output impedance of the UWPT system before and after compensation with respect to the load, provided in the embodiments of this application. Figure 27 This is a schematic diagram of the curves showing the change in secondary output power of the UWPT system before and after compensation with respect to load, provided in an embodiment of this application. Figure 28 This is a schematic diagram of the efficiency curves of the UWPT system before and after compensation as a function of load, provided in an embodiment of this application. Figure 29 This is a schematic diagram of the gain coefficient changing with load, provided in an embodiment of this application; Figure 30 This is a simulation circuit diagram of the secondary equivalent circuit of the UWPT system after LC compensation provided in the embodiments of this application; Figure 31 This is a schematic diagram comparing the voltage stabilization effect of the secondary-side LC compensation network under different K values ​​provided in the embodiments of this application. Detailed Implementation

[0017] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0018] Figure 1 This is a flowchart illustrating the steps of a method for determining circuit parameters in an ultrasonic wireless power transfer system according to an embodiment of this application. The ultrasonic wireless power transfer system includes an energy transfer module and a compensation circuit. The energy transfer module includes a transmitting transducer, a transmission medium, and a receiving transducer. Figure 1 As can be seen from this, the steps of determining the circuit parameters of an ultrasonic wireless power transfer system include: Step S101: Obtain the characteristic admittance curve of the target transducer, which includes a transmitting transducer and / or a receiving transducer.

[0019] In this embodiment, Figure 2This is a schematic diagram of an ultrasonic wireless power transmission system provided in an embodiment of this application. Figure 2 The ultrasonic wireless power transfer system comprises an energy transmitting module, an energy transmitting module, a compensation circuit, and an energy receiving module. The compensation circuit, connected between the energy transmitting and energy transmitting modules, alters the input impedance of the system and increases the driving voltage of the transmitting transducer, thereby eliminating reactive power and increasing transmitted power. The compensation circuit, connected between the energy receiving and energy transmitting modules, reduces the output impedance and stabilizes the output voltage. The connection location of the compensation circuit can be determined based on the specific requirements of the ultrasonic wireless power transfer system. The energy receiving module can be a module consisting of a filter circuit and a load, while the energy transmitting module can be an ultrasonic power supply consisting of a DC power supply and a high-frequency inverter.

[0020] Figure 2 The energy transmission module includes a transmitting transducer, a transmission medium, and a receiving transducer. The transmission medium can be aluminum.

[0021] Since the target transducer includes a transmitting transducer and / or a receiving transducer, the characteristic admittance curve of the target transducer can be obtained by acquiring the input characteristic admittance curve of the transmitting transducer, the output admittance curve of the receiving transducer, or the input admittance curve of the transmitting transducer and the output admittance curve of the receiving transducer. In this embodiment, the characteristic admittance curve is a curve corresponding to admittance and frequency.

[0022] Step S102: Based on the characteristic admittance curve and the preset first relationship model, obtain the parameter values ​​of each component included in the first equivalent circuit. The first equivalent circuit is the equivalent circuit corresponding to the energy transmission module. The first relationship model is determined based on the first equivalent circuit. The first relationship model characterizes the correspondence between the admittance and resonant frequency of the ultrasonic wireless power transmission system and the parameters of each component in the first equivalent circuit.

[0023] In this embodiment, the preset first relationship model is determined by the first equivalent circuit of the energy transmission module. The first equivalent circuit is modeled by the transmitting transducer, the transmission medium, and the receiving transducer, and is specifically a topology composed of series and parallel resistors, inductors, and capacitors. The first relationship model is the correspondence between the admittance and resonant frequency of the ultrasonic wireless power transmission system and the parameters of each component in the first equivalent circuit. The first relationship model can be specifically represented as a multivariate equation system with frequency as the independent variable and parameters such as equivalent series resistance, equivalent series inductance, equivalent series capacitance, and equivalent parallel capacitance in the first equivalent circuit as variables. Specifically, it can be expression (1). When the UWPT system resonates, the resonance relationship is satisfied as shown in expression (2), where , The resonant angular frequency is given by expression (2). The specific expression for the first relational model can be: (1) (2) in, For admittance; This is the equivalent series resistance; It is the equivalent series inductance; It is the equivalent series capacitance; It is an equivalent parallel capacitor; It is the resonant angular frequency; The resonant frequency; This is the operating angular frequency.

[0024] Then, the characteristic admittance curve (admittance data at discrete frequency points) obtained by actual measurement in step S101 is used as a known quantity and substituted into expressions (1) and (2) in the first relational model to obtain the parameter values ​​of each component included in the first equivalent circuit.

[0025] Step S103: Based on the parameter values ​​of each component in the first equivalent circuit and the preset second relationship model, determine the parameter values ​​of each component in the compensation circuit. The second relationship model is determined based on the second equivalent circuit corresponding to the energy transmission module and the compensation circuit. The second relationship model characterizes the correspondence between the impedance of the ultrasonic wireless power transmission system and the parameters of each component in the second equivalent circuit.

[0026] In this embodiment, the second equivalent circuit is a circuit model constructed with the energy transmission module and the compensation circuit as the modeling objects. In addition to the first equivalent circuit, the circuit model also includes a compensation circuit composed of capacitors and inductors. The second relationship model characterizes the correspondence between the parameters of each component in the ultrasonic wireless power transmission system and the second equivalent circuit. Specifically, it can be represented by a set of key performance indicators such as UWPT system efficiency, output power, output voltage and input power factor.

[0027] The parameters of each component of the first equivalent circuit obtained in step S102 are substituted into the second relational model as known constants. The variables in the second relational model are only the parameters of the components to be determined in the compensation circuit. By setting the required UWPT system performance objectives (e.g., achieving maximum transmission efficiency under rated load, controlling output voltage fluctuation within ±5%, and minimizing reactive power on the input side), and transforming these objectives into constraints and optimization objectives for the second relational model, the optimal parameter values ​​of each component of the compensation circuit that meet all comprehensive performance requirements can be directly calculated through numerical solutions or optimization algorithms, thereby solving the problem of coordinated optimization between reactive power, transmission power, and output voltage stability.

[0028] In summary, the circuit parameter determination method for the ultrasonic wireless power transfer system provided in this embodiment can overcome the shortcomings of insufficient accuracy in traditional models by obtaining the characteristic admittance curve reflecting the true coupling characteristics of the UWPT system and performing parameter fitting based on the preset first equivalent circuit topology and first relational model to obtain the parameters of each component included in the first equivalent circuit. Furthermore, the parameters of each component included in the obtained first equivalent circuit are correlated with the performance indicators (efficiency, power, voltage stability, and reactive power characteristics) of the preset second relational model through an optimization model, thereby realizing the systematic synergistic optimization of the UWPT system parameters of the compensation circuit in terms of reactive power, transmission power, and output voltage stability.

[0029] The following three embodiments will illustrate the method for determining the circuit parameters of an ultrasonic wireless power transmission system provided in this embodiment, addressing three scenarios: the target transducer is a transmitting transducer, a receiving transducer, and both a transmitting and receiving transducer.

[0030] Example 1 When the target transducer is a transmitting transducer, the energy transmission module can be constructed from the perspective of the transmitting transducer side, and the first equivalent circuit can be the primary equivalent circuit.

[0031] Figure 3 This is a schematic diagram of the primary-side equivalent circuit provided in the embodiments of this application. Figure 3 It is known that the first equivalent circuit includes a primary-side equivalent circuit, which includes a first equivalent series resistance, a first equivalent series inductance, a first equivalent series capacitance, and a first equivalent parallel capacitance. The first end of the first equivalent series resistance is connected to the first end of the first equivalent parallel capacitance and the positive terminal of the voltage source, respectively. The second end of the first equivalent series resistance is connected to the first end of the first equivalent series inductance, and the second end of the first equivalent series inductance is connected to the first end of the first equivalent series capacitance. The second end of the first equivalent series capacitance is connected to the second end of the first equivalent parallel capacitance and the negative terminal of the voltage source, respectively. The voltage source is configured to input voltage to the energy transmission module.

[0032] The parameter values ​​of the first equivalent series resistance, first equivalent series inductance, first equivalent series capacitance, and first equivalent parallel capacitance contained in the primary-side equivalent circuit can be obtained through the following steps.

[0033] First, the characteristic admittance curve of the target transducer is obtained. Specifically, the input admittance curves of the transmitting transducer under multiple different loads are obtained. Then, the input admittance curve under at least one load is used as the characteristic admittance curve. The input admittance curve is the relationship curve between the frequency and the input admittance of the ultrasonic wireless power transmission system. Then, based on the characteristic admittance curve and the preset first relationship model, the parameter values ​​of each component included in the first equivalent circuit are obtained. Specifically, based on the input admittance curve under at least one load, the resonant frequency of the ultrasonic wireless power transmission system is determined. Then, based on the resonant frequency, the first relationship model is curve-fitted to obtain the fitting result of the input admittance curve matching. The fitting result includes the parameter values ​​of the first equivalent series resistance, the first equivalent series inductance, the first equivalent series capacitance, and the first equivalent parallel capacitance.

[0034] In this embodiment, by connecting an impedance analyzer to both ends of the transmitting transducer, the input admittance curves of the transmitting transducer under multiple different loads are obtained. Figure 4 This is a schematic diagram of the input admittance curves of the transmitting transducer under multiple different loads provided in the embodiments of this application; from Figure 4 It can be seen that the resistance values ​​of the multiple loads are 10Ω, 30Ω, 50Ω, 100Ω, 200Ω, and 300Ω, respectively. When the resistance value of the load changes, the frequency corresponding to the peak value of the input admittance curve hardly changes. Therefore, the input admittance curve under at least one load can be obtained from the impedance analyzer as the characteristic admittance curve, and the resonant frequency of the UWPT system under load can be obtained. Figure 4 The input admittance of the UWPT system reaches its maximum value around 39.71 kHz; while when the UWPT system is unloaded, the input admittance curve reaches its maximum at 40.09 kHz. Therefore, the resonant frequency of the UWPT system under load can be determined. It is 39.71kHz.

[0035] Then, the input admittance curve is fitted using the curve fitting tool in MATLAB. The fitting tool can be CurveFitting. Figure 5 This is a schematic diagram showing the curves of the actual and fitted values ​​of the input admittance with a load of 10Ω as a function of frequency, provided in an embodiment of this application. Figure 5 It can be seen that the process of fitting the input admittance curve with a load of 10Ω can be achieved by selecting the input expression (2) as the target fitting function in the fitting tool interface, selecting the frequency as the X-axis data, and selecting the absolute value of admittance as the Y-axis data, and comparing and analyzing it with the actual input admittance curve obtained by the impedance analyzer. Figure 5 As can be seen, the fitted values ​​highly overlap with the actual values, indicating a good fitting effect. Therefore, it can be considered that the fitted values ​​are consistent with the actual values. Figure 5 The fitting result represents the actual values ​​of the parameters of each component in the primary-side equivalent circuit. When For input admittance; This is the first equivalent series resistance; This is the first equivalent series inductance; This is the first equivalent series capacitance; This is the first equivalent parallel capacitor; It is the resonant angular frequency; The resonant frequency; Given the operating angular frequency, combining expressions (1) and (2), we can obtain the parameter values ​​of each component in the first equivalent circuit of the UWPT system with a load of 10Ω. , , , .

[0036] In addition, it is important to note during the fitting process that the first equivalent series capacitance should be represented by the resonant frequency and the first equivalent series inductance. Otherwise, the fitting will not converge. After obtaining the parameter value of the first equivalent series inductance through fitting, the first equivalent series inductance can be substituted into expression (2) to obtain the parameter value of the first equivalent series capacitance.

[0037] Additionally from Figure 5 As can be seen, the input admittance curve of the UWPT system changes with the load resistance, which is reflected in the changes in the values ​​of each component in the primary-side equivalent circuit of the UWPT system. In other words, different loads correspond to different model parameters. Therefore, to ensure the accuracy of the primary-side equivalent circuit of the UWPT system, the fitting must be re-performed each time the load changes. Using the parameter fitting method described above, the parameters of each component in the primary-side equivalent circuit of the UWPT system under different loads can be obtained. The specific values ​​are shown in Table 1. Table 1 shows the parameters of each component in the primary-side equivalent circuit of the UWPT system under different loads, where the load changes from 10Ω to 100Ω in 10Ω increments.

[0038] Table 1 - Component parameters of the primary-side equivalent circuit of the UWPT system under different loads The UWPT system operates at its resonant frequency. hour, and Resonance, only [remaining] in this branch It can be simplified Figure 5 The primary-side equivalent circuit is Figure 6 , Figure 6 It is aimed at Figure 5 The provided schematic diagram of the primary-side equivalent circuit at the resonant frequency is shown below. Figure 6 As can be seen from this, the input power of the UWPT system P in的 The expression is: (3) Due to the inherent capacitance C of the transmitting transducer p1 Due to the influence of the UWPT system, capacitive reactive power Q will be generated. in reactive power The expression is: (4) in, Indicates inherent capacitance C p1 The capacitive reactance modulus. The power factor of the UWPT system can be expressed by the input impedance angle φ as: (5) Among them, S in This represents the apparent input power of the UWPT system.

[0039] Because of R s1 It increases with the increase of load, therefore, according to expression (3), when the input voltage V in With the input power P remaining constant in The reactive power loss of the UWPT system will decrease monotonically with the increase of the load. As can be seen from expression (4), the reactive power loss of the UWPT system is related to the operating frequency, input voltage, and capacitance of the UWPT system. Therefore, when the structure and operating voltage of the UWPT system are determined and it operates at the resonant frequency, the reactive power loss of the UWPT system is also determined and will not change with the load. Although the magnitude of reactive power will not change with the load, as can be seen from expression (5), the power factor cosφ of the UWPT system will continuously decrease with the increase of the load. At this time, the reactive power ratio of the UWPT system will further increase.

[0040] To eliminate reactive power and increase the input power of the UWPT system, a compensation circuit is added to the transmitting transducer side of the energy transfer module. The compensation circuit is a capacitor and inductor topology and is connected to the transmitting transducer.

[0041] Figure 7 It is aimed at Figure 5 The provided schematic diagram of the compensated primary-side equivalent circuit is from... Figure 7It is known that the compensation circuit includes a first compensation capacitor and a first compensation inductor. The first terminal of the first compensation inductor is connected to the positive terminal of the voltage source, and the second terminal of the first compensation inductor is connected to the first terminal of the first equivalent parallel capacitor and the first terminal of the first equivalent parallel capacitor, respectively. The second terminal of the first compensation capacitor is connected to the negative terminal of the voltage source. Based on the parameter values ​​of each component included in the first equivalent circuit and the preset second relational model, the parameter values ​​of each component included in the compensation circuit are determined, including: obtaining the input impedance, input power, and input voltage of the ultrasonic wireless power transmission system; wherein, the imaginary part of the input impedance is zero; substituting the parameter values ​​of the input impedance, input power, first equivalent series resistance, first equivalent series inductance, first equivalent series capacitor, and first equivalent parallel capacitor into the second relational model, the parameter values ​​of the first compensation capacitor and the first compensation inductor are obtained.

[0042] In this embodiment, determining the parameter values ​​of each component in the compensation circuit requires obtaining the input impedance, input power, and input voltage of the ultrasonic wireless power transmission system. At this point, the input impedance... The expression is: (6) To eliminate capacitive reactive power, an input impedance is required. With the imaginary part being zero, the first compensating inductance can be obtained. and UWPT system input impedance The expressions with only the real part remaining are as follows: (7) (8) Assuming the required UWPT system input power is P, without exceeding the maximum power limit of the transmitting transducer. S Then the input impedance of the UWPT system can be determined as shown in equation (8). According to expressions (7) and (8), the size of the first compensation capacitor C1 can be determined as shown in expression (10). Then, the obtained first compensation capacitor C1 is substituted into equation (7) to obtain the size of the first compensation inductor L1.

[0043] (9) (10) Define the gain coefficient of the transmitting transducer drive voltage before and after compensation as A. v1 The expression is: (11) As the above analysis shows, the gain coefficient is affected by the value of the parallel capacitor C. As the load increases, the equivalent resistance of the series branch increases, leading to a corresponding increase in the parallel capacitor C, which in turn increases the gain coefficient. Therefore, the driving voltage of the transmitting transducer increases monotonically with the increase of the load. The compensation circuit can not only eliminate reactive power and adjust the input impedance to improve the input power, but also improve the driving voltage waveform and increase its effective value.

[0044] Example 2 When the target transducer is a transmitting transducer, the energy transmission module viewed from the receiving transducer side can be constructed as a preset first equivalent circuit as the secondary equivalent circuit.

[0045] Figure 8 This is a schematic diagram of the secondary-side equivalent circuit provided in an embodiment of this application. The first equivalent circuit includes the secondary-side equivalent circuit, from... Figure 8 It can be seen that the secondary equivalent circuit includes a second equivalent series resistance, a second equivalent series inductance, a second equivalent series capacitance, and a second equivalent parallel capacitance. The first end of the second equivalent series resistance is connected to the positive terminal of the equivalent voltage source. The second end of the second equivalent series resistance is connected to the first end of the second equivalent series inductance. The second end of the second equivalent series inductance is connected to the first end of the second equivalent series capacitance. The second end of the second equivalent series capacitance is connected to the first end of the second equivalent parallel capacitance and the first end of the load, respectively. The second end of the second equivalent parallel capacitance is connected to the negative terminal of the equivalent voltage source and the second end of the load.

[0046] Obtaining the characteristic admittance curve of the target transducer includes: obtaining the output admittance curves of the transmitting transducer under multiple different loads, taking the output admittance curve under at least one load as the characteristic admittance curve, and the output admittance curve being the frequency-admittance relationship curve of the ultrasonic wireless power transmission system; obtaining the parameter values ​​of each component included in the first equivalent circuit based on the characteristic admittance curve and a preset first relationship model, including: determining the resonant frequency of the ultrasonic wireless power transmission system based on the output admittance curve under at least one load; and performing curve fitting on the first relationship model based on the resonant frequency to obtain the fitting result of the output admittance curve matching, the fitting result including the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, the second equivalent series capacitance, and the second equivalent parallel capacitance.

[0047] In this embodiment, the characteristic admittance curve of the target transducer is obtained by connecting an impedance analyzer to both ends of the transmitting transducer, short-circuiting both ends of the transmitting transducer, and performing a frequency sweep within a specified frequency range to obtain the output admittance curves of the transmitting transducer under multiple different loads. Then, based on the output admittance curves of the impedance analyzer, the resonant frequency of the UWPT system under load is obtained. The voltage generated by the receiving transducer is then converted using an equivalent voltage source. express.

[0048] from Figure 4 As can be seen, the resonant frequency of the UWPT system differs by 0.38kHz when it is unloaded or loaded. Since frequency has a significant impact on the energy efficiency of the UWPT system, the difference in unloaded voltage at different operating frequencies will also be very large. Therefore, when measuring the unloaded voltage, the operating frequency of the UWPT system should be selected as the resonant frequency under load. Or the no-load resonant frequency This is crucial. For UWPT systems, although the open-circuit voltage is measured with the load open, subsequent energy efficiency analysis targets the UWPT system under load. Therefore, when measuring the open-circuit voltage Voc, the operating frequency of the UWPT system should be selected as the load-resonant frequency. Non-no-load resonant frequency .

[0049] Figure 9 This is a schematic diagram showing the actual and fitted values ​​of the output admittance of an ultrasonic wireless power transmission system as a function of frequency, according to an embodiment of this application. Figure 8 middle, For output admittance; This is the second equivalent series resistance; This is the second equivalent series inductance; This is the second equivalent series capacitance; This is the second equivalent parallel capacitor. It is the resonant angular frequency; The resonant frequency; Given the operating angular frequency, the circuit structure of the secondary equivalent circuit of the UWPT system is the same as that of the transducer equivalent circuit. Parameter measurements can also be performed using curve fitting. Combining expressions (1) and (2), the parameter values ​​of each component in the secondary equivalent circuit of the UWPT system are obtained. , , , .

[0050] In addition to the parameters of passive components such as capacitors, resistors, and inductors, the equivalent voltage source in the secondary-side equivalent circuit also needs to be measured. Size.

[0051] because Since the inside of the receiving transducer cannot be directly measured, in this embodiment, the no-load voltage of the energy transmission module is obtained, and the parameter values ​​of the equivalent voltage source are determined based on the no-load voltage and the parameter values ​​of each component included in the first equivalent circuit. This includes: firstly, obtaining the complex impedance of the first equivalent circuit based on the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, and the second equivalent series capacitance; then, obtaining the equivalent impedance of the first equivalent circuit based on the parameter values ​​of the complex impedance and the second equivalent parallel capacitance; and finally, determining the parameter values ​​of the equivalent voltage source based on the complex impedance, the equivalent impedance, and the no-load voltage.

[0052] First, the UWPT system circuit is simplified. Figure 10 It is aimed at Figure 8 A simplified schematic diagram of the secondary-side equivalent circuit, from Figure 10 It can be seen that it can be , , Unified use of impedance It is indicated that, by using both the Norton transform and the Thevenin transform, the expressions for the no-load voltage and impedance admittance are obtained as follows: (12) from Figure 10 As can be seen from this, when the load is unloaded, the voltage across the receiving transducer is... By measuring the open-circuit voltage Then, by using expression (12), the pickup voltage can be obtained. The value of .

[0053] Figure 11 This is a schematic diagram of the output voltage of a UWPT system provided in an embodiment of this application. Figure 11 As can be seen from the data, when the UWPT system has an input DC voltage of 30V and an operating frequency of 39.71kHz, measurements using an oscilloscope can yield the following results: ,like Figure 11 As shown, the pickup voltage can be further calculated according to expression (12). Combined with Figure 10 It can be seen that the output voltage The expression (13) is: (13) As can be seen from expressions (12) and (13), without changing the coupling structure and transducer of the UWPT system, due to the capacitance C p2 and impedance Z series Z trans2 All are constant values, therefore the output voltage V out Based solely on the pickup voltage V pick and load R LThe decision is made. Given a fixed input voltage, the piezoelectric effect and its inverse indicate that the voltage V picked up by the receiving transducer is... pick The value of is also constant. At this time, the output voltage value depends on the size of the load and shows a monotonically increasing trend as the load increases.

[0054] Based on expression (12), the output power P of the UWPT system can be further obtained. out The expression: (14) Combining expressions (3) and (14), the efficiency of the UWPT system can be obtained. The expression is: (15) For output power P out Find information about the load R. L The derivative: (16) The result can be obtained using expression (16). dP out / dR L When =0, the load condition of the UWPT system is: R L =Z trans2 The above analysis shows that when the load... R L When corresponding to different resistance values dP out / dR L The following expressions are given respectively: (17) As can be seen from expression (17), when the operating frequency of the UWPT system is the resonant frequency and the input voltage remains constant, the output power Pout increases and then decreases with the change of RL. When RL=Ztrans2=42.96Ω, the output power Pout has a maximum value, and at this time the efficiency of the UWPT system η=50%.

[0055] To ensure the introduction of a compensation network does not alter the original structure, when the UWPT system operates at its resonant frequency, the secondary-side equivalent circuit can be simplified to consist of the equivalent resistance of a series branch, a parallel capacitor, and a load. If the series and parallel resistance R... s2 Much smaller than the load R L In this case, voltage regulation can be achieved directly by using parallel inductors.

[0056] Figure 12 This is a schematic diagram of the equivalent circuit of the secondary side using parallel inductor compensation. Figure 12It can be seen that the expression for the parallel inductance L is: (18) At this time, the output impedance Z of the UWPT system out This is equal to the equivalent resistance R of the series branch. s2 Meanwhile, the UWPT system output voltage V out for: (19) As can be seen from the above formula, when the input voltage is fixed, the output voltage V out Size and load R L With output impedance Z out It is related to the ratio of (i.e., the equivalent resistance of the series branch). Since the resistance over the load variation range is much greater than the output impedance Z... out Therefore, the output voltage V of the UWPT system out Able to stabilize at the pickup voltage V pick nearby.

[0057] To reduce output voltage fluctuations, a compensation circuit is connected to the receiving transducer. Figure 13 It is aimed at Figure 8 The provided schematic diagram of the compensated secondary-side equivalent circuit is from... Figure 13 It is known that the compensation circuit includes a second compensation capacitor and a second compensation inductor. The first end of the second compensation inductor is connected to the first end of the second compensation capacitor and the first end of the second equivalent parallel capacitor, respectively. The second end of the second compensation inductor is connected to the first end of the load, and the second end of the second compensation capacitor is connected to the second end of the load and the second end of the second equivalent parallel capacitor, respectively. Based on the parameter values ​​of each component included in the first equivalent circuit and the preset second relationship model, the parameter values ​​of each component included in the compensation circuit are determined, including: obtaining the no-load voltage of the energy transmission module, and determining the parameter values ​​of the equivalent voltage source based on the no-load voltage and the parameter values ​​of each component included in the first equivalent circuit; obtaining the resistance parameter value of the load, and substituting the resistance parameter value, the parameter value of the equivalent voltage source, the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, the second equivalent series capacitor, and the second equivalent parallel capacitor into the second relationship model to obtain the parameter values ​​of the second compensation capacitor and the second compensation inductor.

[0058] In this embodiment, if the resistance is within the range of load variation... The condition of being much smaller than the load RL is not met. In order to reduce the fluctuation of the output voltage, combined with... Figure 13 At this time, the output impedance Z of the UWPT system out The expression is: (20) Setting the imaginary part of the output impedance Zout of the UWPT system to zero, the value of the second compensation inductor can be obtained as follows: (twenty one) At this point, the simplified expression for the output impedance of the UWPT system as a pure resistance is: (twenty two) In summary, the expressions for the second relational model are (20) and (21). To achieve voltage regulation, the load R... L It needs to be much larger than the output impedance Z of the UWPT system. out Therefore, a voltage regulation factor is defined. A larger K value results in better stability. However, increasing the parallel capacitor C to reduce output impedance will excessively lower the output voltage. According to the empirical expression, The value is usually taken as 0.1, but if the required capacitor is too large, it will cause a significant drop in output voltage; therefore, a practical value should be selected. Therefore, the second compensation capacitor C2 can be determined by expression (21) and the size of the target load, and the second compensation inductor L2 can be obtained by expression (20).

[0059] Example 3 When the target transducer is a transmitting transducer, the energy transmission module can be constructed by looking into it from both the transmitting and receiving transducer sides as a preset first equivalent circuit, which is a two-port equivalent circuit.

[0060] The first relational model includes a first sub-model, a second sub-model, and a third sub-model. Figure 14 This is a schematic diagram of a two-port equivalent circuit provided in an embodiment of this application. The first equivalent circuit includes a two-port equivalent circuit, from... Figure 14 It can be seen that the two-port equivalent circuit includes a first sub-circuit, a second sub-circuit, and a third sub-circuit. The first terminal of the first sub-circuit is connected to the positive terminal of the voltage source and the first terminal of the third sub-circuit, respectively. The second terminal of the third sub-circuit is connected to the first terminal of the second sub-circuit and the first terminal of the load, respectively. The second terminal of the second sub-circuit is connected to the first terminal of the first sub-circuit, the negative terminal of the voltage source, and the second terminal of the load, respectively.

[0061] Obtaining the characteristic admittance curve of the target transducer includes: firstly, obtaining the input admittance curve of the receiving transducer when short-circuited and the output admittance curve of the transmitting transducer when short-circuited, and using the input admittance curve and the output admittance curve as the characteristic admittance curve; then, obtaining the input impedance curve of the receiving transducer when open-circuited; based on the characteristic admittance curve and a preset first relationship model, obtaining the parameter values ​​of each component included in the first equivalent circuit, including: firstly, obtaining the input admittance curve, the output admittance curve, and the input impedance curve to obtain the first mutual admittance parameter and the second mutual admittance parameter of the target transducer; and then, comparing the input admittance curve with the first mutual admittance curve... The first admittance characteristic curve of the first sub-circuit is obtained by adding the first admittance parameters. Based on the first admittance characteristic curve and the first sub-model, the parameter values ​​of each component in the first sub-circuit are obtained. The inverse of the first mutual admittance parameter is then used as the second admittance characteristic curve of the second sub-circuit. Based on the second admittance characteristic curve and the second sub-model, the parameter values ​​of each component in the second sub-circuit are obtained. The output admittance curve is added to the second mutual admittance parameter to obtain the third admittance characteristic curve of the third sub-circuit. Based on the third admittance characteristic curve and the third sub-model, the parameter values ​​of each component in the third sub-circuit are obtained.

[0062] In this embodiment, the electrical network composed of passive components such as resistors, inductors, and capacitors is called a passive impedance network, and its input-output relationship can be represented by a two-port network. For Figure 11 The energy transmission section of the UWPT system shown consists of a transmitting transducer, a medium, and a receiving transducer, all of which are passive components and can form a two-port network. Figure 15 This is a schematic diagram of the voltage and current of the energy transfer section of a UWPT system provided in an embodiment of this application. Figure 15 It can be seen that, Input voltage, For input current, For output voltage, This refers to the output current. For the four parameters mentioned above, the resulting two-port parameter matrix will vary depending on the known and unknown quantities. Currently, commonly used two-port parameter matrices include the impedance parameter matrix. Z Admittance parameter matrix Y Transition parameter matrix T and the mixture parameter matrix H Due to the admittance parameter matrix Y This makes it easier to determine the subsequent matrix parameters; therefore, this paper uses the admittance parameter matrix. Y Based on this, the two-port equivalent circuit of the UWPT system is derived.

[0063] for Figure 11 For the two-port network shown, when the input voltage... and output voltage Given that the input current is known, according to the superposition theorem, and output current It can be represented as: (twenty three) in (twenty four) Expression (24) is the admittance parameter matrix of the two-port system, also known as the Y-parameter matrix, and Y... 11 Y 12 Y 21 Y 22 This is called the Y-parameter of the two-port system. According to the definition of the Y-parameter, when port 2-2' is short-circuited, the UWPT system admittance seen from port 1-1' is the Y-parameter. 11 When port 1-1' is short-circuited, the UWPT system admittance seen from port 2-2' is Y. 22 ,Right now: (25) For Y 12 and Y 21 It is defined as the transfer admittance between port 1-1' and port 2-2', which cannot be obtained directly by measuring the port admittance. It needs to be obtained by combining the impedance parameter matrix of the two ports.

[0064] When input current and output current Given that the input voltage is given by the superposition theorem, and output voltage It can be represented as: (26) in (27) This is called the impedance parameter matrix of a two-port circuit, also known as the Z-parameter matrix, and Z... 11 Z 12 Z 21 Z 22 This is called the Z-parameter of the two-port system. According to the definition of the Z-parameter, when port 2-2' is open, the UWPT system impedance seen from port 1-1' is the Z-parameter. 11 When port 1-1' is open, the UWPT system impedance seen from port 2-2' is Z. 22 ,Right now: (28) Based on the mutual conversion relationships between different parameters of a two-port network, Z 11 and Z 22 It can also be expressed as: (29) in (30) Since the energy transfer section is a passive linear two-port circuit, according to the reciprocity condition in circuit theory: (31) At this point, all the parameter expressions in the two-port admittance parameter matrix Y have been obtained. Therefore, the equivalent π-shaped circuit of the two-port system can be derived from matrix Y. Considering the ultrasonic power supply and load based on the equivalent π-shaped circuit, the two-port equivalent circuit of the UWPT system is obtained. Figure 14 The expression for the two-port equivalent circuit is: (32) As can be seen from the above modeling process, the two-port equivalent circuit of the UWPT system has the following advantages: First, Y in the model 11 Y 12 Y 21 Y 22 These parameters are obtained when the UWPT system is open or short-circuited, and are independent of the load. Therefore, when the load changes, the parameters of each component in the two-port equivalent circuit do not need to be changed. A set of parameters can be used to analyze the characteristics of the UWPT system under all load conditions.

[0065] Secondly, the two-port equivalent circuit can completely represent the energy transfer portion of the UWPT system through a circuit, without coupling to the power supply or load. When the circuit structure at both ends of the UWPT system changes, only the same circuit needs to be added at the corresponding locations, without needing to re-measure and fit each parameter. Compared with the model based on equivalent impedance, it is more convenient to simultaneously analyze the characteristics at both ends of the UWPT system.

[0066] Finally, since the two-port equivalent circuit is not based on the transducer equivalent circuit near the resonant frequency, its various network parameters can be measured at any frequency and in any operating mode. Therefore, the applicability of the two-port equivalent circuit is not limited by frequency and transducer operating mode, and it can realize the analysis of the full-band and full-mode characteristics of the UWPT system.

[0067] from Figure 14 It can be seen that the three parameters Y1, Y2, and Y3 need to be determined separately in the two-port equivalent circuit of the UWPT system. As can be seen from expression (32), the above three parameters are related to Y 11 Y 12 Y 21 Y 22 Z 11There are five network parameters, so this section needs to determine the specific values ​​of the above five network parameters in conjunction with the actual UWPT system, and on this basis, determine the specific expressions of Y1, Y2, and Y3.

[0068] According to Y 11 Y 22 Z 11 The definition is that the input admittance curve Y of the UWPT system is measured by an impedance analyzer when the receiving transducer is short-circuited. 11 The output admittance curve Y of the UWPT system was measured when the transmitter transducer was short-circuited. 22 The input impedance curve Z of the UWPT system was measured with the receiving transducer open-circuited. 11 , Figure 16 This is a schematic diagram of the admittance and impedance curves of the UWPT system under different port conditions provided in the embodiments of this application. Figure 16 As can be seen, by comparing the curves of Y11, Y22, and Z11 with frequency with the admittance curve of the transducer, the trends of the curves are consistent. According to the theory of high-frequency AC circuits, the equivalent circuit structure of Y11, Y22, and Z11 can all be represented as LC series and parallel. The specific parameters can be obtained by fitting the admittance curves of Y11 and Z11 using the curve fitting method mentioned in Example 1.

[0069] Y22 is defined as the output admittance curve of the UWPT system when the transmitting transducer is short-circuited. It is consistent with the admittance curve used to determine the component parameters of the UWPT system's secondary equivalent circuit. Therefore, the specific structure of Y22 is also an LC series-parallel circuit, and its value is consistent with the RLC parameters of the secondary equivalent circuit. For Y12 and Y21, since the parameters of each component in Y11, Y22, and Z11 have been determined, the admittance curve of Y12 can also be obtained through expression (32). At the same time, given that the structure of Y11, Y22, and Z11 is determined to be an LC series-parallel circuit, Figure 17 This is a schematic diagram of the theoretical and fitted values ​​of the UWPT system transfer admittance as a function of frequency, provided in the embodiments of this application. Figure 17 As can be seen from expression (31), the circuit structures of Y12 and Y21 are also composed of LC series and parallel circuits. At this time, the specific parameters of Y12 and Y21 can also be obtained by curve fitting. After obtaining the specific expressions for the five parameters Y11, Y12, Y21, Y22, and Z11, the specific expressions for Y1, Y2, and Y3 can be determined based on expression (32) and the parameter fitting method. Table 2 shows the specific fitting results for each parameter in Y11, Y12, Y21, Y22, and Z11.

[0070] Table 2 - Equivalent Circuit Parameters of UWPT System Two-Port Based on the above analysis, it can be concluded that... Figure 14 In the two-port equivalent circuit of the UWPT system shown, Y1, Y2, and Y3 can all be represented as LC series-parallel circuits.

[0071] Figure 18 This is the two-port equivalent circuit of the UWPT system near the resonant frequency provided in the embodiments of this application, from... Figure 18 It can be seen that the first sub-circuit includes a third equivalent series resistance, a third equivalent series inductance, a third equivalent series capacitance, and a third equivalent parallel capacitance. The first terminal of the third equivalent series resistance and the first terminal of the third equivalent parallel capacitance serve as the first terminal of the first sub-circuit, and the second terminals of the third equivalent series capacitance and the third equivalent parallel capacitance serve as the second terminal of the first sub-circuit. The third equivalent series inductance is connected between the second terminal of the third equivalent series resistance and the first terminal of the third equivalent series capacitance. The second sub-circuit includes a fourth equivalent series resistance, a fourth equivalent series inductance, a fourth equivalent series capacitance, and a fourth equivalent parallel capacitance. The first terminal of the fourth equivalent series resistance and the first terminal of the fourth equivalent parallel capacitance serve as the second sub-circuit. The first terminal, the second terminal of the fourth equivalent series capacitor and the second terminal of the fourth equivalent parallel capacitor serve as the second terminal of the second sub-circuit. The fourth equivalent series inductor is connected between the second terminal of the fourth equivalent series resistor and the first terminal of the fourth equivalent series capacitor. The third sub-circuit includes a fifth equivalent series resistor, a fifth equivalent series inductor, a fifth equivalent series capacitor, and a fifth equivalent parallel capacitor. The first terminal of the fifth equivalent series resistor and the first terminal of the fifth equivalent parallel capacitor serve as the first terminal of the third sub-circuit. The second terminal of the fifth equivalent series capacitor and the second terminal of the fifth equivalent parallel capacitor serve as the second terminal of the third sub-circuit. The fifth equivalent series inductor is connected between the second terminal of the fifth equivalent series resistor and the first terminal of the fifth equivalent series capacitor.

[0072] In this embodiment, equivalent circuit parameters are extracted and modeled based on the obtained curves of Y11, Y22, and Z11 as a function of frequency. The specific process is as follows: First, observe the frequency response curves of Y11, Y22, and Z11. Their changing trends are consistent with the admittance characteristic curves of known transducers. According to high-frequency circuit theory, this characteristic indicates that its equivalent circuit structure can also be characterized as an LC series-parallel resonant network. Furthermore, use this circuit structure to establish the corresponding mathematical expression (similar to expressions (1) and (2)).

[0073] By fitting the measured frequency response data of Y11, Y22, and Z11 to the theoretical model in step S2, the specific component parameter values ​​in the equivalent LC networks of Y11, Y22, and Z11 can be accurately extracted. Finally, the parameters obtained from the fitting are substituted into the circuit representing the π-shaped equivalent circuit ( Figure 10The transformation expressions (15) and (16) of the relationship between the two-port network parameters are obtained. By solving these expressions, the expressions for the admittances Y1, Y2, and Y3 of the π-shaped circuit can be directly obtained. Applying the same parameter fitting method as in step S2 again, the frequency response characteristics of Y1, Y2, and Y3 are analyzed, and the values ​​of each discrete component in the two-port equivalent circuit, including Rsi, Lsi, Csi, and Cpi (where i = 3, 4, 5), are determined, thus obtaining... Figure 19 The parameter values ​​of each component in the first, second, and third sub-circuits are provided. Additionally, at the resonant frequency, the parameters can also be... Figure 18 Simplified to Figure 19 ,exist Figure 19 It is aimed at Figure 18 The provided schematic diagram of the two-port equivalent circuit at the resonant frequency only requires obtaining the parameter values ​​of Rsi and Cpi (where i=3, 4, 5).

[0074] In some embodiments, to facilitate the energy efficiency analysis of the secondary side after compensation, LC compensation is adopted on the primary side of the two-port network, that is, a compensation circuit is added to the input side of the two-port equivalent circuit, and the compensation circuit is connected to the voltage source and load of the energy transmission module respectively.

[0075] Figure 20 This is a schematic diagram of the compensated two-port equivalent circuit provided in the embodiments of this application. Figure 20 It is known that the compensation circuit includes a third compensation inductor and a third compensation capacitor. The first terminal of the third compensation inductor is connected to the positive terminal of the voltage source, the second terminal of the third compensation inductor is connected to the first terminal of the third compensation capacitor and the first terminal of the first equivalent circuit, and the second terminal of the third compensation capacitor is connected to the negative terminal of the voltage source. Based on the parameter values ​​of each component included in the first equivalent circuit and the preset second relational model, the parameter values ​​of each component included in the compensation circuit are determined, including: obtaining the input impedance, input power and input voltage of the energy transmission module; wherein, the imaginary part of the input impedance is zero; substituting the input impedance, input power and the parameter values ​​of each component included in the first sub-circuit, the second sub-circuit and the third sub-circuit into the second relational model, the parameter values ​​of the third compensation capacitor and the third compensation inductor are obtained.

[0076] In this embodiment, the compensated two-port transmission parameter matrix is ​​shown in expression (17), and the input impedance of the UWPT system is further derived as shown in expression (18), where Δ Y It is represented as the size of the determinant of the Y parameter.

[0077] (33) (34) (35) Y11, Y22, △ Y The form of real part plus imaginary part is shown in expression (20). Substituting expression (20) into expression (18) yields the expression for the imaginary and real parts of the input impedance as shown in (21). To eliminate reactive power and increase input power, expression (22) must be satisfied, where P S Input power to the UWPT system, and thus obtain the parameter values ​​LC of the third compensation inductor L3 and the third compensation capacitor C3. (36) (37) (38) In the formula V in P is the effective value of the input voltage. s This represents the ideal input power. At this point, the input impedance of the UWPT system only has its real part remaining. real (Z) in Therefore, the output voltage, output power, and efficiency of the UWPT system can ultimately be expressed as: (39) In summary, to verify the change in primary-side energy efficiency parameters of the UWPT system after LC compensation, a simulation circuit after compensation was built based on the equivalent circuit of the primary side of the UWPT system. The simulation used a DC power supply Vin as input, which was converted to AC voltage V2 by a full-bridge inverter and then fed into the LC compensation network. The compensated signal was connected to a load network consisting of Cp1 and Zs1, where Zs1 is a series structure composed of Rs1, Ls1, and Cs1. To analyze the impact of primary-side LC compensation on the UWPT system parameters, the voltage and current waveforms across Zs1 were measured for evaluation.

[0078] Figure 21 This is a simulation circuit diagram of the primary-side equivalent circuit of the UWPT system after LC compensation provided in the embodiments of this application. Figure 21 It can be seen that the simulation preparation only requires calculating the L and C values ​​of the compensation network. From expressions (7) and (10), it can be seen that the L and C values ​​correspond one-to-one with the load and need to be calculated separately according to the load change. It should be noted in the calculation that the input voltage of the UWPT system is a positive and negative square wave containing high-order harmonics. Given that the UWPT system has good frequency selection characteristics, the influence of high-order harmonics on the energy efficiency of the UWPT system can be ignored, so only its fundamental component needs to be considered. Therefore, before substituting into expression (10), the effective value of the square wave needs to be converted into the effective value of the fundamental wave. The conversion relationship is as follows: (40) At ideal input power P s =60W, Input DC voltage V inWith a voltage of 30V and an operating frequency of 39.71kHz, the specific data of the parallel capacitor C and series inductor L under different loads were obtained, as shown in Table 3. The load ranged from 10Ω to 100Ω in 10Ω increments.

[0079] Table 3. Inductance and capacitance parameters of the LC compensation network under different loads. Figure 22 This is a schematic diagram showing the curves of the primary-side input impedance of the UWPT system before and after compensation as a function of the load, provided in the embodiments of this application. Figure 23 This is a schematic diagram showing the curves of the primary-side input power of the UWPT system before and after compensation as a function of load, provided in the embodiments of this application. Figure 24 This is a schematic diagram of the curves showing the change of the driving voltage of the transmitting transducer before and after compensation with the load, provided in the embodiments of this application.

[0080] from Figure 22 , Figure 23 and Figure 24 It can be seen that the input impedance angle φ and the input power P in The simulation value of the transmitting transducer drive voltage V1 varies with the load, where the blue curve represents the data before compensation and the red curve represents the data after compensation.

[0081] like Figure 22 As shown, with increasing load, the input impedance angle of the UWPT system before compensation drops from -3.86° to -10.15° and continues to deteriorate, severely reducing power efficiency. After adding LC compensation, the input impedance angle can be stably maintained at 0°, effectively eliminating the influence of reactive power. Figure 23 This indicates that before compensation, the input power of the UWPT system monotonically decreases with increasing load, consistent with theoretical analysis; after adding LC compensation, the input power stabilizes at around 58.1W, close to the transducer's rated power of 60W, with the error within an acceptable range. According to... Figure 24 Before compensation, the driving voltage of the transmitter transducer was equal to the input voltage of the UWPT system. After LC compensation, the driving voltage was significantly increased and showed a monotonically increasing trend with the increase of load, which is consistent with the theoretical analysis.

[0082] To further verify the secondary-side energy efficiency of the UWPT system after primary-side LC compensation. Figure 25 This is a simulation circuit diagram of the two-port equivalent circuit of the UWPT system after LC compensation provided in the embodiments of this application. Figure 24It can be seen that the UWPT system uses a DC power supply Vin as input, which is converted into an AC voltage V2 by a full-bridge inverter circuit, and then fed into an LC compensation network composed of an inductor L and a capacitor C. The compensated signal is connected to a two-port network defined by its Y parameters (Y11, Y12, Y22), and finally drives the load RL. To verify the secondary-side energy efficiency characteristics of the UWPT system after LC compensation on the primary side, the current waveforms across the load RL are measured and analyzed.

[0083] Figure 26 This is a schematic diagram of the curves showing the change of the secondary output impedance of the UWPT system before and after compensation with respect to the load, provided in the embodiments of this application. Figure 27 This is a schematic diagram of the curves showing the change in secondary output power of the UWPT system before and after compensation with respect to load, provided in an embodiment of this application. Figure 28 This is a schematic diagram of the efficiency curves of the UWPT system before and after compensation as a function of load, provided in an embodiment of this application. Figure 29 This is a schematic diagram of the gain coefficient changing with load, provided in an embodiment of this application; from Figure 26 , Figure 27 , Figure 28 and Figure 29 It can be seen that, Figure 26 The output voltage variation curve with load is shown. According to the piezoelectric effect, with the UWPT system coupling structure unchanged, the output voltage is proportional to the transmitting transducer drive voltage. Theoretical analysis indicates that LC compensation significantly increases the drive voltage; therefore, the output voltage should also increase proportionally. Figure 27 It is known that before compensation, the output power of the UWPT system first increases and then decreases with increasing load, reaching a peak at around 40Ω; after LC compensation, the output power increases monotonically with load, and the rate of increase gradually slows down. The efficiency of the UWPT system is essentially determined by the electromechanical conversion efficiency of the transducer and its coupling strength with the dielectric. Without changing this premise, Figure 28 The results show that the efficiency of the UWPT system remains basically unchanged before and after compensation, which is consistent with the theoretical analysis.

[0084] To verify Figure 26 The conclusion, Figure 29 The output voltage gain coefficient is defined and compared with the drive voltage gain coefficient. Figure 23 The results show that the two curves basically overlap and remain consistent with the load changes, thus verifying the correctness of the theoretical analysis.

[0085] To verify the effectiveness of the secondary-side LC compensation network in reducing output voltage fluctuations in a UWPT system, this application constructs an energy efficiency optimization simulation circuit based on the equivalent circuit of the secondary side of the UWPT system using MATLAB / Simulink. Figure 30This is a simulation circuit diagram of the equivalent secondary circuit of the UWPT system after LC compensation provided in the embodiments of this application. Figure 30 As can be seen, in the simulation, the obtained pickup voltage Vpick and impedance Zseries (named ZS2 in the simulation) are used as inputs and connected to the circuit composed of LC compensation network and load RL to finally obtain the output voltage waveform across the load.

[0086] In the energy efficiency analysis of the UWPT system in Example 2, it was mentioned that the output power of the UWPT system reaches its maximum when the load is around 40Ω. Therefore, this paper uses the output voltage at a load of 40Ω as the voltage regulation standard. To further verify the difference in output voltage between K=0.1 and K=0.3, this paper conducts simulation analysis on the output voltage under different K values. With the UWPT system operating at its resonant frequency, the parameters of the LC compensation network under different K values ​​are shown in Table 4.

[0087] Table 4 - Parameters of LC compensation network under different K values Based on the above parameters, at the input voltage V in With a voltage of 30V, an operating frequency at the resonant frequency, and a load that varies from 10Ω to 100Ω in 10Ω increments, the output voltage curves as a function of the load under different voltage regulation coefficient values ​​can be simulated. Figure 31 This is a schematic diagram comparing the voltage stabilization effect of the secondary-side LC compensation network under different K values ​​provided in the embodiments of this application. Figure 31 As can be seen, the black curve represents the output voltage variation with load before adding LC compensation, the blue curve represents the output voltage variation with load when K=0.1, and the red curve represents the output voltage variation with load when K=0.3. Before adding LC compensation, the UWPT system output voltage fluctuates significantly with load changes. When the load changes from 10Ω to 100Ω, the UWPT system output voltage increases from 5.04V to 18.49V. When the load changes from 40Ω to 50Ω, the output voltage increases by 1.48V, an increase of 11.53%. When the load changes from 40Ω to 30Ω, the output voltage decreases by 1.88V, a decrease of 14.64%.

[0088] Comparing different voltage regulation coefficients, it was found that when K=0.1, the output voltage fluctuation was significantly suppressed (the voltage only increased from 5.78V to 7.78V when the load varied between 10Ω and 100Ω), but the required parallel capacitor was too large (nearly 300nF), causing the output voltage to drop sharply from 12.84V before compensation to 7.35V (a decrease of 42.76%), resulting in a serious loss of energy efficiency in the UWPT system. While the voltage regulation effect was slightly less effective when K=0.3 (the voltage increased from 6.37V to 12.51V when the load varied between 10Ω and 100Ω), the output voltage could be maintained at around 11V, and the drop (approximately 16%) was within an acceptable range. Therefore, to avoid a significant decrease in energy efficiency, this application ultimately selected K=0.3, which achieves a better balance between effective voltage regulation and maintaining the output voltage.

[0089] In summary, this application employs an innovative modeling approach that treats the "transducer-medium" as a whole, fundamentally avoiding the inherent errors caused by the simplification of complex coupling interfaces in traditional methods. Therefore, the established model more realistically reflects the actual physical processes of the UWPT system, and the error between the model's predicted and measured values ​​of the UWPT system's external characteristics (such as transmission efficiency and output power) is significantly reduced. Secondly, the core parameters of the two-port network model constructed in this application have been proven to be related only to the transmitting / receiving transducers and the medium itself, and independent of the load. Furthermore, the model parameters are obtained by fitting admittance data over a wide bandwidth. Therefore, this model is no longer bound to a single resonant point like traditional models. The model maintains accurate characterization under wide bandwidth and varying load conditions, exhibiting excellent versatility and adaptability. Finally, since this application provides a set of different equivalent circuits for the primary side, secondary side, and the core power transmission part of the UWPT system, the most suitable model can be directly selected according to the specific design task (such as primary side compensation, secondary side voltage regulation, or channel optimization). There is no longer a need to rely on a large and complex single model. The direct result is that different parts of the UWPT system can be designed and optimized in parallel and independently, significantly enhancing the design flexibility and efficiency of UWPT system development.

[0090] In a second aspect of this application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory. When the computer program is executed by the processor, it implements the steps of the method for determining circuit parameters of the ultrasonic wireless power transmission system according to the embodiments of this application.

[0091] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0092] This application describes embodiments of methods and apparatus according to flowchart illustrations and / or block diagrams. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0093] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0094] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0095] The circuit parameter determination method and electronic device of the ultrasonic wireless power transmission system provided in this application have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this application. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method of determining circuit parameters of an ultrasonic wireless power transfer system, characterized by, The ultrasonic wireless power transmission system comprises an energy transmission module and a compensation circuit, the energy transmission module comprises a transmitting transducer, a transmission medium and a receiving transducer, and the method comprises: obtaining a characteristic admittance curve of a target transducer, the target transducer comprising the transmitting transducer and / or the receiving transducer; based on the characteristic admittance curve and a preset first relationship model, obtaining parameter values of each element contained in a first equivalent circuit, the first equivalent circuit being an equivalent circuit corresponding to the energy transmission module, the first relationship model being determined based on the first equivalent circuit, and the first relationship model representing a corresponding relationship between admittance, resonance frequency of the ultrasonic wireless power transmission system and parameter values of each element in the first equivalent circuit; based on the parameter values of each element contained in the first equivalent circuit and a preset second relationship model, determining parameter values of each element contained in the compensation circuit, the second relationship model being determined based on a second equivalent circuit corresponding to the energy transmission module and the compensation circuit, and the second relationship model representing a corresponding relationship between impedance of the ultrasonic wireless power transmission system and parameter values of each element in the second equivalent circuit.

2. The method of claim 1, wherein, The target transducer is the transmitting transducer, the compensation circuit is connected with the transmitting transducer, the first equivalent circuit comprises a primary side equivalent circuit, the primary side equivalent circuit comprises a first equivalent series resistance, a first equivalent series inductance, a first equivalent series capacitance and a first equivalent parallel capacitance, a first end of the first equivalent series resistance is connected with a first end of the first equivalent parallel capacitance and a positive electrode of a voltage source respectively, a second end of the first equivalent series resistance is connected with a first end of the first equivalent series inductance, a second end of the first equivalent series inductance is connected with a first end of the first equivalent series capacitance, a second end of the first equivalent series capacitance is connected with a second end of the first equivalent parallel capacitance and a negative electrode of the voltage source respectively, and the voltage source is configured to input a voltage to the energy transmission module; The method comprises: obtaining an input admittance curve of the transmitting transducer under a plurality of different loads, and taking the input admittance curve under at least one load as the characteristic admittance curve, the input admittance curve being a relationship curve between frequency and input admittance of the ultrasonic wireless power transmission system; based on the characteristic admittance curve and a preset first relationship model, obtaining parameter values of each element contained in a first equivalent circuit, the first equivalent circuit being an equivalent circuit corresponding to the energy transmission module, the first relationship model being determined based on the first equivalent circuit, and the first relationship model representing a corresponding relationship between admittance, resonance frequency of the ultrasonic wireless power transmission system and parameter values of each element in the first equivalent circuit; based on the parameter values of each element contained in the first equivalent circuit and a preset second relationship model, determining parameter values of each element contained in the compensation circuit, the second relationship model being determined based on a second equivalent circuit corresponding to the energy transmission module and the compensation circuit, and the second relationship model representing a corresponding relationship between impedance of the ultrasonic wireless power transmission system and parameter values of each element in the second equivalent circuit. The target transducer is the transmitting transducer, the compensation circuit is connected with the transmitting transducer, the first equivalent circuit comprises a primary side equivalent circuit, the primary side equivalent circuit comprises a first equivalent series resistance, a first equivalent series inductance, a first equivalent series capacitance and a first equivalent parallel capacitance, a first end of the first equivalent series resistance is connected with a first end of the first equivalent parallel capacitance and a positive electrode of a voltage source respectively, a second end of the first equivalent series resistance is connected with a first end of the first equivalent series inductance, a second end of the first equivalent series inductance is connected with a first end of the first equivalent series capacitance, a second end of the first equivalent series capacitance is connected with a second end of the first equivalent parallel capacitance and a negative electrode of the voltage source respectively, and the voltage source is configured to input a voltage to the energy transmission module; The method comprises: obtaining an input admittance curve of the transmitting transducer under a plurality of different loads, and taking the input admittance curve under at least one load as the characteristic admittance curve, the input admittance curve being a relationship curve between frequency and input admittance of the ultrasonic wireless power transmission system; based on the characteristic admittance curve and a preset first relationship model, obtaining parameter values of each element contained in a first equivalent circuit, the first equivalent circuit being an equivalent circuit corresponding to the energy transmission module, the first relationship model being determined based on the first equivalent circuit, and the first relationship model representing a corresponding relationship between admittance, resonance frequency of the ultrasonic wireless power transmission system and parameter values of each element in the first equivalent circuit; based on the parameter values of each element contained in the first equivalent circuit and a preset second relationship model, determining parameter values of each element contained in the compensation circuit, the second relationship model being determined based on a second equivalent circuit corresponding to the energy transmission module and the compensation circuit, and the second relationship model representing a corresponding relationship between impedance of the ultrasonic wireless power transmission system and parameter values of each element in the second equivalent circuit.

3. The method of claim 2, wherein, The compensation circuit includes a first compensation capacitor and a first compensation inductor. The first end of the first compensation inductor is connected to the positive terminal of the voltage source. The second end of the first compensation inductor is connected to the first end of the first equivalent parallel capacitor and the first end of the first equivalent parallel capacitor, respectively. The second end of the first compensation capacitor is connected to the negative terminal of the voltage source. Based on the parameter values ​​of each component in the first equivalent circuit and a preset second relationship model, the parameter values ​​of each component in the compensation circuit are determined, including: Obtain the input impedance, input power, and input voltage of the ultrasonic wireless power transmission system; wherein the imaginary part of the input impedance is zero; Substituting the parameter values ​​of the input impedance, the input power, the first equivalent series resistance, the first equivalent series inductance, the first equivalent series capacitance, and the first equivalent parallel capacitance into the second relationship model, the parameter values ​​of the first compensation capacitor and the first compensation inductance are obtained.

4. The method of claim 1, wherein, The target transducer is the receiving transducer, and the compensation circuit is connected to the receiving transducer. The first equivalent circuit includes a secondary equivalent circuit, which includes a second equivalent series resistance, a second equivalent series inductance, a second equivalent series capacitance, and a second equivalent parallel capacitance. The first end of the second equivalent series resistance is connected to the positive terminal of the equivalent voltage source, the second end of the second equivalent series resistance is connected to the first end of the second equivalent series inductance, the second end of the second equivalent series inductance is connected to the first end of the second equivalent series capacitance, the second end of the second equivalent series capacitance is connected to the first end of the second equivalent parallel capacitance and the first end of the load, and the second end of the second equivalent parallel capacitance is connected to the negative terminal of the equivalent voltage source and the second end of the load. The acquisition of the characteristic admittance curve of the target transducer includes: The output admittance curves of the transmitting transducer under multiple different loads are obtained, and the output admittance curve under at least one load is taken as the characteristic admittance curve. The output admittance curve is the relationship curve between frequency and admittance of the ultrasonic wireless power transmission system. Based on the characteristic admittance curve and the preset first relationship model, the parameter values ​​of each component included in the first equivalent circuit are obtained, including: The resonant frequency of the ultrasonic wireless power transfer system is determined based on the output admittance curve under at least one load. Based on the resonant frequency, the first relationship model is subjected to curve fitting to obtain the fitting result of the output admittance curve matching. The fitting result includes the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, the second equivalent series capacitance, and the second equivalent parallel capacitance.

5. The method of claim 4, wherein, The compensation circuit includes a second compensation capacitor and a second compensation inductor. The first end of the second compensation inductor is connected to the first end of the second compensation capacitor and the first end of the second equivalent parallel capacitor, respectively. The second end of the second compensation inductor is connected to the first end of the load, and the second end of the second compensation capacitor is connected to the second end of the load and the second end of the second equivalent parallel capacitor, respectively. Based on the parameter values ​​of each component in the first equivalent circuit and a preset second relationship model, the parameter values ​​of each component in the compensation circuit are determined, including: Obtain the no-load voltage of the energy transmission module, and determine the parameter values ​​of the equivalent voltage source based on the no-load voltage and the parameter values ​​of each component included in the first equivalent circuit. Obtain the resistance parameter value of the load, and substitute the resistance parameter value, the parameter value of the equivalent voltage source, the parameter value of the second equivalent series resistance, the second equivalent series inductance, the second equivalent series capacitance, and the second equivalent parallel capacitance into the second relationship model to obtain the parameter values ​​of the second compensation capacitor and the second compensation inductor.

6. The method of claim 5, wherein, Obtain the no-load voltage of the energy transmission module, and determine the parameter values ​​of the equivalent voltage source based on the no-load voltage and the parameter values ​​of each component included in the first equivalent circuit, including: Based on the parameter values ​​of the second equivalent series resistance, the second equivalent series inductance, and the second equivalent series capacitance, the complex impedance of the first equivalent circuit is obtained. Based on the parameter values ​​of the complex impedance and the second equivalent parallel capacitor, the equivalent impedance of the first equivalent circuit is obtained. Based on the complex impedance, the equivalent impedance, and the no-load voltage, the parameter values ​​of the equivalent voltage source are determined.

7. The method of claim 1, wherein, The target transducer includes the transmitting transducer and the receiving transducer. The compensation circuit is connected to the voltage source and the load of the energy transmission module, respectively. The first relational model includes a first sub-model, a second sub-model, and a third sub-model. The first equivalent circuit includes a two-port equivalent circuit, which includes a first sub-circuit, a second sub-circuit, and a third sub-circuit. The first terminal of the first sub-circuit is connected to the positive terminal of the voltage source and the first terminal of the third sub-circuit, respectively. The second terminal of the third sub-circuit is connected to the first terminal of the second sub-circuit and the first terminal of the load, respectively. The second terminal of the second sub-circuit is connected to the first terminal of the first sub-circuit, the negative terminal of the voltage source, and the second terminal of the load, respectively. Obtain the characteristic admittance curve of the target transducer, including: Obtain the input admittance curve when the receiving transducer is short-circuited and the output admittance curve when the transmitting transducer is short-circuited, and use the input admittance curve and the output admittance curve as characteristic admittance curves; The method further includes: Obtain the input impedance curve of the receiving transducer when it is open-circuited; Based on the characteristic admittance curve and the preset first relationship model, the parameter values ​​of each component included in the first equivalent circuit are obtained, including: By acquiring the input admittance curve, the output admittance curve, and the input impedance curve, the first mutual admittance parameter and the second mutual admittance parameter of the target transducer are obtained. The input admittance curve is added to the first mutual admittance parameter to obtain the first admittance characteristic curve of the first sub-circuit, and the parameter values ​​of each component included in the first sub-circuit are obtained based on the first admittance characteristic curve and the first sub-model. The negative of the first mutual admittance parameter is used as the second admittance characteristic curve of the second sub-circuit, and the parameter values ​​of each component included in the second sub-circuit are obtained based on the second admittance characteristic curve and the second sub-model. The output admittance curve is added to the second mutual admittance parameter to obtain the third admittance characteristic curve of the third sub-circuit. Based on the third admittance characteristic curve and the third sub-model, the parameter values ​​of each component included in the third sub-circuit are obtained.

8. The method of claim 7, wherein, The compensation circuit includes a third compensation inductor and a third compensation capacitor. The first terminal of the third compensation inductor is connected to the positive terminal of the voltage source. The second terminal of the third compensation inductor is connected to the first terminal of the third compensation capacitor and the first terminal of the first equivalent circuit, respectively. The second terminal of the third compensation capacitor is connected to the negative terminal of the voltage source. Based on the parameter values ​​of each component in the first equivalent circuit and a preset second relationship model, the parameter values ​​of each component in the compensation circuit are determined, including: Obtain the input impedance, input power, and input voltage of the energy transfer module; wherein the imaginary part of the input impedance is zero; Substituting the input impedance, the input power, and the parameter values ​​of each component in the first sub-circuit, the second sub-circuit, and the third sub-circuit into the second relationship model, we obtain the parameter values ​​of the third compensation capacitor and the third compensation inductor.

9. The method of claim 7, wherein, The first sub-circuit includes a third equivalent series resistance, a third equivalent series inductance, a third equivalent series capacitance, and a third equivalent parallel capacitance. The first end of the third equivalent series resistance and the first end of the third equivalent parallel capacitance serve as the first end of the first sub-circuit, and the second end of the third equivalent series capacitance and the second end of the third equivalent parallel capacitance serve as the second end of the first sub-circuit. The third equivalent series inductance is connected between the second end of the third equivalent series resistance and the first end of the third equivalent series capacitance. The second sub-circuit includes a fourth equivalent series resistance, a fourth equivalent series inductance, a fourth equivalent series capacitance, and a fourth equivalent parallel capacitance. The first end of the fourth equivalent series resistance and the first end of the fourth equivalent parallel capacitance serve as the first end of the second sub-circuit, and the second end of the fourth equivalent series capacitance and the second end of the fourth equivalent parallel capacitance serve as the second end of the second sub-circuit. The fourth equivalent series inductance is connected between the second end of the fourth equivalent series resistance and the first end of the fourth equivalent series capacitance. The third sub-circuit includes a fifth equivalent series resistance, a fifth equivalent series inductance, a fifth equivalent series capacitance, and a fifth equivalent parallel capacitance. The first end of the fifth equivalent series resistance and the first end of the fifth equivalent parallel capacitance serve as the first end of the third sub-circuit, and the second end of the fifth equivalent series capacitance and the second end of the fifth equivalent parallel capacitance serve as the second end of the third sub-circuit. The fifth equivalent series inductance is connected between the second end of the fifth equivalent series resistance and the first end of the fifth equivalent series capacitance.

10. An electronic device comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program, when executed by the processor, is arranged to perform the method of any one of claims 1 to 9. When the computer program is executed by the processor, it implements the steps of the method for determining the circuit parameters of the ultrasonic wireless power transmission system according to any one of claims 1 to 9.

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