A Parameter Identification Method for a Quadrupole Underwater Electric Field Wireless Power Transfer System

Abstract

This invention discloses a parameter identification method for a four-plate underwater electric field-type wireless power transfer system, comprising a DC power supply and a high-frequency inverter, a transmitting plate module, a receiving plate module, a system load, and a sampling and control module. When the system is transmitting power normally, this invention operates in a resonant state. By adjusting the load impedance, it collects information on the voltage and current at the inverter output terminal, calculates the system's input impedance under different loads, and uses equations to solve for the parameters between the system plates. Parameter identification can be achieved simply by collecting the voltage and current at the inverter output terminal, without adding complex circuits or changing the system's driving frequency. The steps are simple and can effectively identify various parameters between the system plates under seawater conditions.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission, and in particular to a method for parameter identification of a four-pole underwater electric field wireless power transmission system. Background Technology

[0002] Compared to traditional wired charging, wireless charging technology offers advantages in safety, reliability, and flexibility, making it particularly suitable for harsh electrical environments such as coal mines and underwater environments. Compared to magnetically coupled resonant wireless power transfer systems, electric field-coupled wireless power transfer systems are less expensive and more suitable for large-scale deployment in the vast ocean. Furthermore, electric field-coupled wireless power transfer systems are not affected by eddy currents in underwater environments, significantly improving system transmission efficiency and stability.

[0003] Autonomous underwater vehicles (AUVs) play a vital role in both civilian and military applications. An AUV is an unmanned underwater vehicle that navigates underwater, offering advantages such as autonomous control, greater flexibility in maritime operations, and enhanced stealth. However, during underwater wireless charging, the impact of seawater fluctuations can cause misalignment of the AUV's docking position on the charging platform. This leads to uncertainties in the resistance values ​​between the system's electrodes, affecting charging efficiency and power, and reducing the AUV's battery life. Therefore, accurately identifying the resistance values ​​between the system's electrodes is crucial. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, this application proposes a parameter identification method for a quadrupole underwater electric field wireless power transfer system to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A method for parameter identification of a quadrupole underwater electric field-based wireless power transfer system includes the following steps:

[0007] Step 1: Construct the circuit topology of the four-plate wireless power transfer system. The circuit topology specifically includes: a DC power supply, a high-frequency inverter, a transmitting plate module, a seawater equivalent impedance circuit, a receiving plate module, a system load, and a sampling and control module. The DC power supply is connected to the input terminal of the high-frequency inverter. The output terminal of the high-frequency inverter is connected to the input terminal of the transmitting plate module. The output terminal of the transmitting plate module is connected to the input terminal of the seawater equivalent impedance circuit. The output terminal of the seawater equivalent impedance circuit is directly opposite the input terminal of the receiving plate module. The output terminal of the receiving plate module is connected to the system load. The input ports of the sampling and control module are connected to the output terminal of the high-frequency inverter and the system load, respectively, and the output port is connected to the system load. The seawater equivalent impedance circuit is a Π-type equivalent circuit, consisting of an equivalent resistance R. Π1R Π2 R Π3 Composition; the system load is the actual system load R F A parallel circuit consisting of an adjustable resistor R used only for parameter identification is controlled by a switch;

[0008] Step 2: Fix the system operating frequency, and obtain the four equivalent capacitances C1, C2, C3, and C4 of the insulating layer based on the dimensions and relative permittivity of the electrode insulating layer, and calculate its parasitic resistance R. C1 R C2 R C3 R C4 Adjust the compensation inductors L1 and L2 according to the capacitance value to make the system work in the resonant state, and calculate its parasitic resistance R. L1 R L2 ;

[0009] Step 3: Connect three system loads with different resistance values ​​respectively, obtain the voltage and current at the output of the high-frequency inverter, and calculate the corresponding input impedances Z1, Z2 and Z3 of the system respectively;

[0010] Step 4: Determine the equivalent circuit of the four-plate wireless power transfer system at resonance. Based on Kirchhoff's voltage and current laws, obtain a set of equations relating the input impedance, load resistance, parasitic resistance, and the equivalent resistance of the seawater.

[0011] Step 5: Substitute the input impedance, parasitic resistance, and load resistance obtained in steps 2, 3, and 4 into the equations from step 4 to obtain the equivalent resistance R between the plates. Π1 R Π2 R Π3 This enables parameter recognition.

[0012] As a further technical solution of the present invention: step 2 specifically includes:

[0013] Step 2.1, using the area S, thickness d, and relative permittivity ε of the insulating layer on the electrode surface. w The equivalent capacitance of the insulating layer on the surface of each electrode plate was calculated.

[0014] In the formula, ε0 represents the dielectric constant of vacuum;

[0015] Step 2.2: Adjust the compensation inductors L1 and L2 according to the obtained capacitance value and the system operating frequency to make the system work in the resonant state;

[0016] Step 2.3: Use an impedance analyzer to measure the parasitic resistance of the capacitor and the compensating inductor respectively.

[0017] As a further technical solution of the present invention: step 3 specifically includes:

[0018] Step 3.1: Control the load resistance of the system to R1, apply voltage and determine if the system is working normally; record the voltage U1 and current I1 at the output of the high-frequency inverter at this time;

[0019] Step 3.2: Control the load resistance of the system to R2, apply voltage and determine if the system is working normally; record the voltage U2 and current I2 at the output of the high-frequency inverter at this time;

[0020] Step 3.3: Control the load resistance of the system to R3, apply voltage and determine if the system is working normally; record the voltage U3 and current I3 at the output of the high-frequency inverter at this time;

[0021] Step 3.4: Calculate the system input impedances Z1 = U1 / I1, Z2 = U2 / I2, and Z3 = U3 / I3 respectively.

[0022] In the formula, Z1, Z2, and Z3 represent the system input impedances under three different load conditions; U1, U2, and U3 represent the high-frequency inverter output voltages under three different load conditions; and I1, I2, and I3 represent the high-frequency inverter output currents under three different load conditions.

[0023] As a further technical solution of the present invention: step 4 specifically includes:

[0024] Step 4.1: Simplify the system circuit to an equivalent circuit when the system is at resonance;

[0025] Step 4.2, the equations constructed based on the equivalent circuit at resonance are as follows:

[0026]

[0027] In the formula, a1, a2, a3, b1, b2, and b3 represent intermediate variables.

[0028] As a further technical solution of the present invention: the high-frequency inverter adopts a single-phase full-bridge inverter circuit, and the output voltage is a square wave with a fixed duty cycle, satisfying the formula: U ab V is the fundamental effective value of the output voltage of the high-frequency inverter. DC This is the output DC voltage value of the DC power supply.

[0029] As a further technical solution of the present invention: the emitter plate module includes a first plate, a third plate, and a first compensation inductor; one end of the compensation inductor is connected to one output terminal of the high-frequency inverter, and the other end of the compensation inductor is connected to one end of the first plate; the other end of the third plate is connected to the other output terminal of the high-frequency inverter;

[0030] The inherent resonant frequency of the emitter electrode module satisfies the formula: Where, ω T C represents the inherent resonant frequency of the emitter electrode module. T L represents the capacitance of the emitter plate. T This represents the compensating inductance of the emitter plate.

[0031] As a further technical solution of the present invention: the receiving electrode module includes a second electrode, a fourth electrode, and a second compensation inductor; one end of the compensation inductor is connected to the input terminal of the system load, and the other end of the compensation inductor is connected to one end of the second electrode; the other end of the fourth electrode is connected to the output terminal of the system load;

[0032] The inherent resonant frequency of the receiving electrode module satisfies the formula: Where, ω S C represents the inherent resonant frequency of the receiving electrode module. S L represents the capacitance value of the receiving plate. S This represents the compensating inductance of the receiving plate.

[0033] As a further technical solution of the present invention: the seawater equivalent impedance circuit consists of six resistors R 12 R 13 R 14 R 23 R 24 R 34 Equivalent to three resistors R of type Π Π1 R Π2 R Π3 Among them, the resistance R 12 R 13 R 14 R 23 R 24 R 34 These are the mutual resistances between the first, second, third, and fourth plates, respectively.

[0034] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0035] This invention provides a parameter identification method for a four-plate underwater electric field wireless power transfer system based on variable load. This technology can quickly solve for the resistance between the system plates by switching the load resistance. This technology does not require changing the system's driving frequency or adding complex circuits. The steps are simple and can quickly and accurately meet the parameter identification requirements. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0037] Figure 2 This is a detailed circuit topology diagram of the present invention;

[0038] Figure 3 The equivalent circuit diagram of the system resonance state of the present invention is shown below.

[0039] Figure 4 This is a flowchart of the parameter identification process of the present invention;

[0040] Figure 5 This is a graph showing the relationship between the equivalent resistance between the system plates of the present invention and the distance between the transmitting and receiving plates.

[0041] Figure 6 This is a graph showing the relationship between the output power and efficiency of the system of the present invention and the distance between the transmitting and receiving plates. Detailed Implementation

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] like Figure 1-6 As shown, a parameter identification method for a quadrupole underwater electric field-based wireless power transfer system based on variable load is disclosed. The method specifically includes the following steps:

[0044] Step 1: Construct the circuit topology of the four-plate wireless power transmission system. The circuit topology specifically includes: DC power supply 1, high-frequency inverter 2, transmitting plate module 3, seawater equivalent impedance circuit 4, receiving plate module 5, system load 6, and sampling and control module 7.

[0045] In this configuration, DC power supply 1 is connected to the input terminal of high-frequency inverter 2, the output terminal of high-frequency inverter 2 is connected to the input terminal of transmitter plate module 3, the output terminal of transmitter plate module 3 is connected to the input terminal of seawater equivalent impedance circuit 4, the output terminal of seawater equivalent impedance circuit 4 is directly opposite to the input terminal of receiver plate module 5, the output terminal of receiver plate module 5 is connected to system load 6, and the input port of sampling and control module 7 is connected to the output terminal of high-frequency inverter 2 and system load 6 respectively, and the output port is connected to system load 6.

[0046] The seawater equivalent impedance circuit 4 is a Π-type equivalent circuit, consisting of an equivalent resistance R. Π1 R Π2 R Π3 Composition; the system load 6 is the actual system load R. FA parallel circuit consisting of an adjustable resistor R used only for parameter identification is controlled by a switch.

[0047] Step 2: Fix the system operating frequency, and obtain the four equivalent capacitances C1, C2, C3, and C4 of the insulating layer based on the dimensions and relative permittivity of the electrode insulating layer, and calculate its parasitic resistance R. C1 R C2 R C3 R C4 Adjust the compensation inductors L1 and L2 according to the capacitance value to make the system work in the resonant state, and calculate its parasitic resistance R. L1 R L2 The specific method is as follows:

[0048] Step 2.1, using the area S, thickness d, and relative permittivity ε of the insulating layer on the electrode surface. w The equivalent capacitance of the insulating layer on the surface of each electrode plate was calculated.

[0049] In the formula, ε0 represents the dielectric constant of vacuum;

[0050] Step 2.2: Adjust the compensation inductors L1 and L2 according to the obtained capacitance value and the system operating frequency to make the system work in the resonant state;

[0051] Step 2.3: Use an impedance analyzer to measure the parasitic resistance of the capacitor and the compensating inductor respectively;

[0052] Step 3: Connect three system loads 6 with different resistance values ​​respectively, obtain the voltage and current at the output terminal of the high-frequency inverter 2, and calculate the corresponding input impedances Z1, Z2, and Z3 of the system respectively; the specific method is as follows:

[0053] Step 3.1: Control the load 6 of the system with resistance R1, apply voltage and determine that the system is working normally; record the voltage U1 and current I1 at the output terminal of the high-frequency inverter 2 at this time;

[0054] Step 3.2: Control the load 6 of the system to have a resistance of R2, apply voltage and determine that the system is working normally; record the voltage U2 and current I2 at the output terminal of the high-frequency inverter 2 at this time;

[0055] Step 3.3: Control the load 6 of the system to have a resistance of R3, apply voltage and determine that the system is working normally; record the voltage U3 and current I3 at the output terminal of the high-frequency inverter 2 at this time;

[0056] Step 3.4: Calculate the system input impedances Z1 = U1 / I1, Z2 = U2 / I2, and Z3 = U3 / I3 respectively.

[0057] In the formula, Z1, Z2, and Z3 represent the system input impedances under three different load conditions; U1, U2, and U3 represent the output voltages of the high-frequency inverter 2 under three different load conditions; and I1, I2, and I3 represent the output currents of the high-frequency inverter 2 under three different load conditions.

[0058] Step 4: Determine the equivalent circuit of the four-plate wireless power transfer system at resonance. Based on Kirchhoff's voltage and current laws, obtain a set of equations relating the input impedance, load resistance, parasitic resistance, and the equivalent resistance of the seawater.

[0059] Step 4.1, simplify the system circuit at system resonance as follows: Figure 3 The equivalent circuit;

[0060] Step 4.2, the equations constructed based on the equivalent circuit at resonance are as follows:

[0061]

[0062]

[0063] In the formula, a1, a2, a3, b1, b2, and b3 represent intermediate variables.

[0064] Step 5: Substitute the input impedance, parasitic resistance, and load resistance obtained in steps 2, 3, and 4 into the equations from step 4 to obtain the equivalent resistance R between the plates. Π1 R Π2 R Π3 This enables parameter recognition. The specific method is as follows:

[0065] Calculate the parameters in Formula 3 based on the system load values ​​R1, R2, and R3. Substitute the parameters from Formula 3 into Formula 2 to calculate the parameters in Formula 2. Substitute the parameters from Formula 2 into Formula 1 and combine them with the input impedance values ​​Z1, Z2, and Z3 to calculate the equivalent resistance R. Π1 R Π2 R Π3 .

[0066] Preferably, the high-frequency inverter 2 adopts a single-phase full-bridge inverter circuit, and the output voltage is a square wave with a fixed duty cycle, satisfying the formula: U ab V is the fundamental effective value of the output voltage of the high-frequency inverter. DC This is the output DC voltage value of DC power supply 1.

[0067] Preferably, the emitter plate module 3 includes a first plate, a third plate, and a first compensation inductor; one end of the compensation inductor is connected to one output terminal of the high-frequency inverter 2, and the other end of the compensation inductor is connected to one end of the first plate; the other end of the third plate is connected to the other output terminal of the high-frequency inverter 2.

[0068] The inherent resonant frequency of the emitter electrode module satisfies the formula: Where, ω T C represents the inherent resonant frequency of the emitter electrode module. T L represents the capacitance of the emitter plate. T This represents the compensating inductance of the emitter plate.

[0069] Preferably, the receiving electrode module 5 includes a second electrode, a fourth electrode, and a second compensating inductor; one end of the compensating inductor is connected to the input terminal of the system load 6, and the other end of the compensating inductor is connected to one end of the second electrode; the other end of the fourth electrode is connected to the output terminal of the system load 6.

[0070] The inherent resonant frequency of the receiving electrode module satisfies the formula: Where, ω S C represents the inherent resonant frequency of the receiving electrode module. S L represents the capacitance value of the receiving plate. S This represents the compensating inductance of the receiving plate.

[0071] Preferably, the seawater equivalent impedance circuit 4 consists of six mutual resistors R 12 R 13 R 14 R 23 R 24 R 34 Equivalent to three resistors R of type Π Π1 R Π2 R Π3 ;

[0072] Wherein, resistance R 12 R 13 R 14 R 23 R 24 R 34 These are the mutual resistances between the first, second, third, and fourth plates, respectively.

[0073] The following is a specific embodiment of the present invention.

[0074] Step 1: Construct the circuit topology diagram of the four-plate wireless power transfer system;

[0075] refer to Figure 1The circuit topology diagram of the four-plate wireless power transmission system shown is as follows: DC power supply 1, high-frequency inverter 2, transmitting plate module 3, seawater equivalent impedance circuit 4, receiving plate module 5, system load 6, and sampling and control module 7.

[0076] The system's DC input voltage V DC The voltage is 100V, the system drive frequency is 200kHz, both the transmitter and receiver modules are made of aluminum plates, and the insulating material is mica with a dielectric constant of 5.7; the conductivity of seawater is set to 4; MAXWELL simulation yields R... 12 =88.527Ω, R 13 =1.1534Ω, R 14 =95.3198Ω, R 23 =106.3739Ω, R 24 =0.97876Ω, R 34 =114.812Ω, equivalent to Π-type resistors R Π1 = 2.15486Ω, R Π2 = 46.97976Ω, R Π3 =53.4769Ω; the three different load resistors are set as R1=48Ω, R2=50Ω, and R3=51Ω respectively;

[0077] Step 2: Fix the system operating frequency, and obtain the four equivalent capacitances C1, C2, C3, and C4 of the insulating layer based on the dimensions and relative permittivity of the electrode insulating layer, and calculate its parasitic resistance R. C1 R C2 R C3 R C4 Adjust the compensation inductors L1 and L2 according to the capacitance value to make the system work in the resonant state, and calculate its parasitic resistance R. L1 R L2 The specific method is as follows:

[0078] Step 2.1, the area of ​​the insulating layer on the electrode surface is S = 25600 mm². 2 Thickness d = 10 mm and relative permittivity ε w =5.7; via formula The calculated equivalent capacitance values ​​of the insulating layer on the surface of each electrode plate are C1 = 1.3564 nF, C2 = 1.3805 nF, C3 = 1.3563 nF, and C4 = 1.3804 nF, respectively.

[0079] In the formula, ε0 represents the dielectric constant of vacuum;

[0080] Step 2.2: Based on the obtained capacitance value and the system operating frequency f = 200kHz, adjust the compensation inductors L1 and L2 to both be 925.585μH so that the system operates in a resonant state;

[0081] Step 2.3: Use an impedance analyzer to measure the parasitic resistance R of the capacitors. C1 =1.125Ω, R C2 =0.959Ω, R C3 = 1.1298Ω, R C4 = 0.961Ω; Parasitic resistance R of the compensating inductor L1 R L1 Both are 2Ω;

[0082] Step 3: Connect three system loads 6 with different resistance values ​​respectively, obtain the voltage and current at the output terminal of the high-frequency inverter 2, and calculate the corresponding input impedances Z1, Z2, and Z3 of the system respectively; the specific method is as follows:

[0083] Step 3.1: Control the load 6 of the system with a resistance of R1 = 48Ω, apply voltage and determine that the system is working normally; record the voltage U1 and current I1 at the output terminal of the high-frequency inverter 2 at this time;

[0084] Step 3.2: Control the load 6 of the system with a resistance of R2 = 50Ω, apply voltage and determine that the system is working normally; record the voltage U2 and current I2 at the output terminal of the high-frequency inverter 2 at this time;

[0085] Step 3.3: Control the load 6 of the system with a resistance of R3 = 51Ω, apply voltage and determine that the system is working normally; record the voltage U3 and current I3 at the output terminal of the high-frequency inverter 2 at this time;

[0086] Step 3.4: Calculate the system input impedances Z1 = U1 / I1, Z2 = U2 / I2, and Z3 = U3 / I3 respectively.

[0087] In the formula, Z1, Z2, and Z3 represent the system input impedances under three different load conditions; U1, U2, and U3 represent the output voltages of the high-frequency inverter 2 under three different load conditions; and I1, I2, and I3 represent the output currents of the high-frequency inverter 2 under three different load conditions.

[0088] In this example, the calculated input impedances of the system are Z1 = 21.83919Ω, Z2 = 22.032804Ω, and Z3 = 22.12601Ω.

[0089] Step 4: Determine the equivalent circuit of the four-plate wireless power transfer system at resonance. Based on Kirchhoff's voltage and current laws, obtain a set of equations relating the input impedance, load resistance, parasitic resistance, and the equivalent resistance of the seawater. The specific method is as follows:

[0090] Step 4.1, simplify the system circuit at system resonance as follows: Figure 3 The equivalent circuit;

[0091] Step 4.2, the equations constructed based on the equivalent circuit at resonance are as follows:

[0092]

[0093] In the formula, a1, a2, a3, b1, b2, and b3 represent intermediate variables;

[0094] Step 5: Substitute the input impedance, parasitic resistance, and load resistance obtained in steps 2, 3, and 4 into the equations from step 4 to obtain the equivalent resistance R between the plates. Π1 R Π2 R Π3 This enables parameter recognition. The specific method is as follows:

[0095] Calculate parameters a1, a2, and a3 in Formula 3 based on system load values ​​R1, R2, and R3. Substitute the parameters from Formula 3 into Formula 2 to calculate parameters b1, b2, and b3. Substitute the parameters from Formula 2 into Formula 1 and combine them with input impedance values ​​Z1, Z2, and Z3 to calculate the equivalent resistance R. Π1 R Π2 R Π3 In this embodiment, R is calculated. Π1 =2.131Ω, R Π2 = 44.92Ω, R Π3 =56.296Ω, thus enabling parameter identification. (Reference) Figure 5 , Figure 6 By comparing the simulated values ​​with the assumed theoretical values, it can be seen that the error value is small, which fully demonstrates that the method used in this invention is feasible and effective.

[0096] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0097] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment have been appropriately combined to form other embodiments that are easy for those skilled in the art to understand.

Claims

1. A method for parameter identification of a four-pole underwater electric field-based wireless power transfer system, characterized in that: Includes the following steps: Step 1: Construct the circuit topology of the four-plate wireless power transfer system. The circuit topology specifically includes: a DC power supply, a high-frequency inverter, a transmitting plate module, a seawater equivalent impedance circuit, a receiving plate module, a system load, and a sampling and control module. The DC power supply is connected to the input terminal of the high-frequency inverter. The output terminal of the high-frequency inverter is connected to the input terminal of the transmitting plate module. The output terminal of the transmitting plate module is connected to the input terminal of the seawater equivalent impedance circuit. The output terminal of the seawater equivalent impedance circuit is directly opposite the input terminal of the receiving plate module. The output terminal of the receiving plate module is connected to the system load. The input ports of the sampling and control module are connected to the output terminal of the high-frequency inverter and the system load, respectively, and the output port is connected to the system load. The seawater equivalent impedance circuit is a Π-type equivalent circuit, consisting of an equivalent resistance R. Π1 R Π2 R Π3 Composition; the system load is the actual system load R F A parallel circuit consisting of an adjustable resistor R used only for parameter identification is controlled by a switch; Step 2: Fix the system operating frequency, and obtain the four equivalent capacitances C1, C2, C3, and C4 of the insulating layer based on the dimensions and relative permittivity of the electrode insulating layer, and calculate its parasitic resistance R. C1 R C2 R C3 R C4 Adjust the compensation inductors L1 and L2 according to the capacitance value to make the system work in the resonant state, and calculate its parasitic resistance R. L1 R L2 ; Step 3: Connect three system loads with different resistance values ​​respectively, obtain the voltage and current at the output of the high-frequency inverter, and calculate the corresponding input impedances Z1, Z2 and Z3 of the system respectively; Step 4: Determine the equivalent circuit of the four-plate wireless power transfer system at resonance. Based on Kirchhoff's voltage and current laws, obtain a set of equations relating the input impedance, load resistance, parasitic resistance, and the equivalent resistance of the seawater. Step 5: Substitute the input impedance, parasitic resistance, and load resistance obtained in steps 2, 3, and 4 into the equations from step 4 to obtain the equivalent resistance R between the plates. Π1 R Π2 R Π3 This enables parameter recognition.

2. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 1, characterized in that, Step 2 specifically includes: Step 2.1, using the area S, thickness d, and relative permittivity ε of the insulating layer on the electrode surface. w The equivalent capacitance of the insulating layer on the surface of each electrode plate was calculated. In the formula, ε0 represents the dielectric constant of vacuum; Step 2.2: Adjust the compensation inductors L1 and L2 according to the obtained capacitance value and the system operating frequency to make the system work in the resonant state; Step 2.3: Use an impedance analyzer to measure the parasitic resistance of the capacitor and the compensating inductor respectively.

3. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 1, characterized in that, Step 3 specifically includes: Step 3.1: Control the load resistance of the system to R1, apply voltage and determine if the system is working normally; record the voltage U1 and current I1 at the output of the high-frequency inverter at this time; Step 3.2: Control the load resistance of the system to R2, apply voltage and determine if the system is working normally; record the voltage U2 and current I2 at the output of the high-frequency inverter at this time; Step 3.3: Control the load resistance of the system to R3, apply voltage and determine if the system is working normally; record the voltage U3 and current I3 at the output of the high-frequency inverter at this time; Step 3.4: Calculate the system input impedances Z1 = U1 / I1, Z2 = U2 / I2, and Z3 = U3 / I3 respectively. In the formula, Z1, Z2, and Z3 represent the system input impedances under three different load conditions; U1, U2, and U3 represent the high-frequency inverter output voltages under three different load conditions; and I1, I2, and I3 represent the high-frequency inverter output currents under three different load conditions.

4. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 1, characterized in that, Step 4 specifically includes: Step 4.1: Simplify the system circuit to an equivalent circuit when the system is at resonance; Step 4.2, the equations constructed based on the equivalent circuit at resonance are as follows: In the formula, a1, a2, a3, b1, b2, and b3 represent intermediate variables.

5. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 4, characterized in that, The high-frequency inverter adopts a single-phase full-bridge inverter circuit, and the output voltage is a square wave with a fixed duty cycle, satisfying the formula: U ab V is the fundamental effective value of the output voltage of the high-frequency inverter. DC This is the output DC voltage value of the DC power supply.

6. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 1, characterized in that, The emitter plate module includes a first plate, a third plate, and a first compensation inductor; one end of the compensation inductor is connected to one output terminal of the high-frequency inverter, and the other end of the compensation inductor is connected to one end of the first plate; the other end of the third plate is connected to the other output terminal of the high-frequency inverter. The inherent resonant frequency of the emitter electrode module satisfies the formula: Where, ω T C represents the inherent resonant frequency of the emitter electrode module. T L represents the capacitance of the emitter plate. T This represents the compensating inductance of the emitter plate.

7. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 1, characterized in that, The receiving electrode module includes a second electrode, a fourth electrode, and a second compensating inductor; one end of the compensating inductor is connected to the input terminal of the system load, and the other end of the compensating inductor is connected to one end of the second electrode; the other end of the fourth electrode is connected to the output terminal of the system load. The inherent resonant frequency of the receiving electrode module satisfies the formula: Where, ω S C represents the inherent resonant frequency of the receiving electrode module. S L represents the capacitance value of the receiving plate. S This represents the compensating inductance of the receiving plate.

8. The parameter identification method for a four-pole underwater electric field wireless power transfer system according to claim 1, characterized in that, The seawater equivalent impedance circuit consists of six resistors R. 12 R 13 R 14 R 23 R 24 R 34 Equivalent to three resistors R of type Π Π1 R Π2 R Π3 ; Wherein, resistance R 12 R 13 R 14 R 23 R 24 R 34 These are the mutual resistances between the first, second, third, and fourth plates, respectively.

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