An optimization control method and device of a bidirectional underwater wireless charging system

Abstract

The disclosure provides an optimization control method and device of a bidirectional underwater wireless charging system, wherein the optimization control method of the bidirectional underwater wireless charging system comprises: determining an equivalent voltage phasor representation of a primary-secondary circuit; determining a total loss representation of the underwater wireless charging system; minimizing the total loss representation of the underwater wireless charging system to determine an optimized ratio of equivalent voltage phasor amplitudes of the primary-secondary circuit and an optimized phase difference value of the equivalent voltage phasors of the primary-secondary circuit; determining the equivalent voltage phasors of the optimized primary-secondary circuit; and determining an alternating current voltage phasor of the optimized primary-secondary circuit according to a preset internal-external phase shift angle. Through the disclosure, the coil current of the primary-secondary circuit is optimized, the synthetic eddy current electric field loss and the parasitic loss of the circuit are reduced, the efficiency and interoperability of the bidirectional underwater wireless charging system are improved, and the reduction of system efficiency caused by parameter asymmetry is prevented.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of underwater wireless power transfer, in particular, to an optimization control method and device of a bidirectional underwater wireless charging system. BACKGROUND

[0002] Compared with the traditional wired charging method, wireless charging (WPT) is attracting more and more attention due to its strong autonomy and environmental adaptability. The wireless charging system not only can get rid of the cable and be free from the influence of corrosive seawater, but also can omit the process of manual plugging, which is very suitable for the application scenario of autonomous underwater vehicles (AUVs). Large scientific devices are an important development direction of AUVs, which need a unified charging base to provide charging services for multiple vehicles in a given sea area, thereby putting forward higher requirements for the interoperability of the wireless charging system, involving the seamless transmission of electric energy between different transmitting and receiving levels.

[0003] When different transmitting and receiving levels are interoperated, due to the differences in power, voltage level, coil parameters and battery model, and the unpredictable asymmetry of the electrical and mechanical parameters of the wireless charging system. The seawater medium has the characteristic of significantly higher conductivity than the air medium, and thus the current flowing in the coil will excite eddy current field in the seawater medium between the coils, resulting in eddy current loss. The generation of eddy current loss will cause the underwater wireless charging system to be less efficient than the wireless charging system in the air medium.

[0004] At present, the research on effectively reducing eddy current loss is still relatively scarce. The traditional method mainly adjusts the frequency to reduce the synthetic eddy current field, but this frequency conversion strategy is not universal and is difficult to realize interoperability. Therefore, a more reliable and easier-to-implement interoperable underwater wireless charging system is urgently needed. SUMMARY

[0005] In view of the defects in the prior art, the purpose of the present disclosure is to provide an optimization control method and device of a bidirectional underwater wireless charging system.

[0006] According to one aspect of the present disclosure, an optimization control method of a bidirectional underwater wireless charging system is provided, comprising:

[0007] The preset transmission power, the ratio parameter of the equivalent voltage phasor amplitude of the primary and secondary circuits, and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits are used to represent the equivalent voltage phasor of the primary and secondary circuits, and the equivalent voltage phasor of the primary and secondary circuits is determined.

[0008] The ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the phase difference parameter of the equivalent voltage phasor of the primary-secondary side circuit are used to represent the parasitic loss and the synthetic eddy current electric field loss of the primary-secondary side circuit, and a total loss representation of the underwater wireless charging system is determined;

[0009] The total loss representation of the underwater wireless charging system is minimized to determine the ratio of the equivalent voltage phasor amplitude of the optimized primary-secondary side circuit and the phase difference of the equivalent voltage phasor of the optimized primary-secondary side circuit;

[0010] According to the ratio of the equivalent voltage phasor amplitude of the optimized primary-secondary side circuit and the phase difference of the equivalent voltage phasor of the optimized primary-secondary side circuit, and the equivalent voltage phasor representation of the primary-secondary side circuit, the equivalent voltage phasor of the optimized primary-secondary side circuit is determined.

[0011] According to the equivalent voltage vector of the optimized primary-secondary side circuit and the preset internal-external phase shift angle, the AC voltage phasor of the optimized primary side circuit and the AC voltage phasor of the optimized secondary side circuit are determined.

[0012] Optionally, the method further comprises:

[0013] According to the AC voltage phasor of the optimized primary side circuit and the AC voltage phasor of the optimized secondary side circuit, the bidirectional underwater wireless charging system is controlled.

[0014] Optionally, the ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the phase difference parameter of the equivalent voltage phasor of the primary-secondary side circuit are used to represent the parasitic loss and the synthetic eddy current electric field loss of the primary-secondary side circuit, and the total loss representation of the underwater wireless charging system is determined, comprising:

[0015] The ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the phase difference parameter of the equivalent voltage phasor of the primary-secondary side circuit are used to represent the parasitic loss of the primary-secondary side circuit, and a parasitic loss representation of the primary-secondary side circuit is determined.

[0016] The ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the phase difference parameter of the equivalent voltage phasor of the primary-secondary side circuit are used to represent the synthetic eddy current electric field loss, and a synthetic eddy current electric field loss representation is determined.

[0017] The parasitic loss representation of the primary-secondary side circuit and the synthetic eddy current electric field loss representation are summed to determine the total loss representation of the underwater wireless charging system.

[0018] Optionally, the ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the phase difference value parameter of the equivalent voltage phasor of the primary-secondary side circuit represent the parasitic loss of the primary-secondary side circuit, and determining the parasitic loss representation of the primary-secondary side circuit comprises:

[0019] The equivalent voltage phasor representation of the primary-secondary side circuit represents the current of each loop of the primary-secondary side circuit.

[0020] According to the current representation of each loop and the total resistance value representation of each loop, the parasitic loss representation of the primary-secondary side circuit is determined.

[0021] Optionally, the ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the phase difference value parameter of the equivalent voltage phasor of the primary-secondary side circuit represent the parasitic loss of the primary-secondary side circuit, and determining the parasitic loss representation of the primary-secondary side circuit comprises:

[0022] The coil current parameter of the primary-secondary side circuit represents the synthesized eddy current electric field strength, and the synthesized eddy current electric field strength representation is determined.

[0023] According to the synthesized eddy current electric field strength representation, the volume integral processing is performed on the preset eddy current loss region, and the synthesized eddy current electric field loss representation is determined.

[0024] Optionally, the coil current parameter of the primary-secondary side circuit represents the synthesized eddy current electric field strength representation, and the synthesized eddy current electric field strength representation is determined.

[0025] The coil current parameter of the primary-secondary side circuit represents the primary eddy current electric field strength and the secondary eddy current electric field strength, and the primary eddy current electric field strength representation and the secondary eddy current electric field strength representation are determined.

[0026] According to the primary eddy current electric field strength representation and the secondary eddy current electric field strength representation, the synthesized eddy current electric field strength representation is determined.

[0027] Optionally, the total loss representation of the underwater wireless charging system is minimized to determine the optimized ratio of the equivalent voltage phasor amplitude of the primary-secondary side circuit and the optimized phase difference value of the equivalent voltage phasor of the primary-secondary side circuit.

[0028] The total loss representation of the underwater wireless charging system is differentiated with respect to the ratio parameter of the equivalent voltage phasor amplitude of the primary-secondary side circuit, and the ratio of the equivalent voltage phasor amplitude of the primary-secondary side circuit corresponding to the minimum value of the total loss of the underwater wireless charging system is determined as the optimized ratio of the equivalent voltage phasor amplitude of the primary-secondary side circuit.

[0029] Derivate the phase difference value parameter of the equivalent voltage phasor of the primary side and secondary side circuit represented by the total loss of the underwater wireless charging system, and determine the phase difference value of the equivalent voltage phasor of the primary side and secondary side circuit corresponding to the minimum value of the total loss of the underwater wireless charging system as the optimized equivalent voltage phase difference value of the primary side and secondary side circuit.

[0030] Optionally, the determining the optimized equivalent voltage phasor of the primary side and secondary side circuit according to the ratio of the amplitude of the equivalent voltage phasor of the optimized primary side and secondary side circuit, the phase difference value of the equivalent voltage phasor of the optimized primary side and secondary side circuit, and the equivalent voltage phasor representation of the primary side and secondary side circuit comprises:

[0031] The preset transmission power, the ratio of the amplitude of the equivalent voltage phasor of the optimized primary side and secondary side circuit, and the phase difference value of the equivalent voltage phasor of the optimized primary side and secondary side circuit are substituted into the equivalent voltage phasor representation of the primary side and secondary side circuit to determine the equivalent voltage phasor of the optimized primary side and secondary side circuit.

[0032] Optionally, the method further comprises:

[0033] sharing the parameter information of the primary side circuit and the parameter information of the secondary side circuit;

[0034] identifying the mutual inductance of the primary side circuit and the secondary side circuit.

[0035] According to a second aspect of the present disclosure, a bidirectional underwater wireless charging control method is provided, comprising:

[0036] a first determining module configured to represent the equivalent voltage phasor of the primary side and secondary side circuit by the preset transmission power, the ratio of the amplitude of the equivalent voltage phasor of the primary side and secondary side circuit, and the phase difference value of the equivalent voltage phasor of the primary side and secondary side circuit, and determine the equivalent voltage phasor representation of the primary side and secondary side circuit;

[0037] a loss determining module configured to represent the parasitic loss and the synthetic eddy current electric field loss of the primary side and secondary side circuit by the ratio of the amplitude of the equivalent voltage phasor of the primary side and secondary side circuit and the phase difference value of the equivalent voltage phasor of the primary side and secondary side circuit, and determine the total loss representation of the underwater wireless charging system;

[0038] a second determining module configured to minimize the total loss representation of the underwater wireless charging system, and determine the ratio of the amplitude of the equivalent voltage phasor of the optimized primary side and secondary side circuit and the phase difference value of the equivalent voltage phasor of the optimized primary side and secondary side circuit;

[0039] a first optimization module configured to determine an equivalent voltage phasor of the optimized primary-secondary circuit according to a ratio of magnitudes of equivalent voltage phasors of the optimized primary-secondary circuit, a phase difference value of the equivalent voltage phasors of the optimized primary-secondary circuit, and the equivalent voltage phasor representation of the primary-secondary circuit;

[0040] a second optimization module configured to determine an AC voltage phasor of the optimized primary circuit and an AC voltage phasor of the optimized secondary circuit according to the equivalent voltage vector of the optimized primary-secondary circuit and preset internal-external phase shift angles.

[0041] Compared with the prior art, the embodiments of the present disclosure have at least one of the following beneficial effects:

[0042] By the above technical solution, by minimizing the total loss representation of the bidirectional underwater wireless charging system, the equivalent voltage phasor of the primary-secondary circuit of the bidirectional underwater wireless charging system is optimized and controlled, and then the current distribution in the resonant network loop is optimized, the synthetic eddy current electric field excited by the primary-secondary coil current in the seawater medium is reduced, thereby reducing the synthetic eddy current electric field loss and the parasitic loss of the circuit, realizing the efficiency optimization of the bidirectional underwater wireless charging system, preventing the system efficiency from being reduced due to the parameter asymmetry of the transmitting end and the receiving end, and improving the interoperability of the bidirectional underwater wireless charging system. BRIEF DESCRIPTION OF DRAWINGS

[0043] Other features, objects, and advantages of the present disclosure will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0044] Figure 1 is a flowchart of an optimization control method of a bidirectional underwater wireless charging system according to an example embodiment.

[0045] Figure 2 is a topological schematic diagram of a bidirectional underwater wireless charging system based on a double-sided LCC compensation network according to an example embodiment.

[0046] Figure 3 is a schematic diagram of the coil current of two groups of coils placed in parallel in the cylindrical coordinate system and the induced electric field excited thereby according to an example embodiment.

[0047] Figure 4 is a schematic diagram of the relationship between the transmission power, the parasitic loss of the circuit, the synthetic eddy current electric field loss, and the system efficiency, and the ratio parameter λ of the magnitudes of the equivalent voltage phasors of the primary-secondary circuit and the phase difference value θ of the equivalent voltages of the primary-secondary circuit according to an example embodiment.

[0048] Figure 5It is a schematic diagram of the comparison between the coil current and the eddy current field of any point position in the coil of the system before and after the optimization of the equivalent voltage phasor of the primary side circuit according to an exemplary embodiment.

[0049] Figure 6 It is a flow chart of an optimization control device of a bidirectional underwater wireless charging system according to an exemplary embodiment. DETAILED DESCRIPTION

[0050] The present disclosure will be described in detail below with specific embodiments. The following embodiments will help those skilled in the art to further understand the present disclosure, but do not limit the present disclosure in any form. It should be noted that for those skilled in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made. These all belong to the protection scope of the present disclosure.

[0051] Figure 1 It is a flow chart of an optimization control method of a bidirectional underwater wireless charging system according to an exemplary embodiment. Figure 2 It is a topology schematic diagram of a bidirectional underwater wireless charging system based on a double-sided LCC compensation network according to an exemplary embodiment.

[0052] As shown in Figure 1 , Figure 2 , the present disclosure provides an optimization control method of a bidirectional underwater wireless charging system, which can be applied to a bidirectional underwater wireless charging system based on a double-sided LCC compensation network, wherein the LCC resonance network has a strong filtering effect, and the current flowing through the transmission coil can only contain a fundamental component, and the power transmission between the primary side circuit and the secondary side circuit is mainly realized by the fundamental component, thereby simplifying the bidirectional underwater wireless charging system into the form of a topology diagram as shown in Figure 2 .

[0053] As shown in Figure 2 , in the primary side circuit, the primary side circuit includes an inverter voltage source U AB of the primary side circuit, a series compensation inductor L f1 of the primary side circuit, a parallel compensation capacitor C p1 of the primary side circuit, a series compensation capacitor C f1 , a coil L p , wherein the inverter voltage source of the primary side circuit is connected in series with the series compensation inductor L f1 of the primary side circuit, the series compensation capacitor C f1 and the coil L p of the primary side circuit, and the parallel compensation capacitor C p1 of the primary side circuit is connected in parallel with the series branch of the series compensation capacitor C f1 and the coil L p .

[0054] wherein i AB represents the inverter current of the primary side circuit, i p represents the current flowing through the coil L p of the primary side circuit. The resistance R p is used to represent the internal resistance of the coil L p of the primary side circuit, the resistance R f1 is used to represent the parasitic resistance of the resonant inductance of the primary side circuit, i.e. the parasitic resistance of the series compensation inductance L f1 .

[0055] As shown in Fig. Figure 2 , in the secondary side circuit, the secondary side circuit comprises an inverter voltage source U ab of the secondary side circuit, a series compensation inductance L f1 of the secondary side circuit, a parallel compensation capacitor C p2 of the secondary side circuit, a series compensation capacitor C f2 , a coil L s , wherein the inverter voltage source of the secondary side circuit is connected in series with the series compensation inductance L f2 , the series compensation capacitor C f2 and the coil L s of the secondary side circuit, and the parallel compensation capacitor C p2 of the secondary side circuit is connected in parallel with the series branch of the series compensation capacitor C f2 and the coil L s .

[0056] wherein i ab represents the inverter current of the secondary side circuit, i s represents the current flowing through the coil of the secondary side circuit. The resistance R s is used to represent the internal resistance of the coil L s of the secondary side circuit, the resistance R f2 is used to represent the parasitic resistance of the resonant inductance of the secondary side circuit, i.e. the parasitic resistance of the series compensation inductance L f2 of the secondary side circuit.

[0057] As shown in Fig. Figure 2 , M represents the mutual inductance of the coil L p of the primary side circuit and the coil L s of the secondary side circuit, E eddy represents the eddy current electric field excited by the coil current flowing through the coil L p of the primary side circuit and the coil L s of the secondary side circuit in the seawater medium.

[0058] To achieve efficient energy transmission of the primary and secondary side circuits, the resonant frequency of the primary side circuit is the same as the resonant frequency of the secondary side circuit, and is the same as the working frequency of the circuit.

[0059] The preset resonant angular frequency of the primary and secondary side circuits is ω0=2πf0, and the parameters of the double-sided LCC compensation network satisfy the following relationships:

[0060]

[0061] wherein ω0 represents the resonant angular frequency of the primary and secondary side circuits, L f1 represents the series compensation inductance of the primary side circuit, C p1 represents the parallel compensation capacitance of the primary side circuit, L f2 represents the series compensation inductance of the secondary side circuit, C p2 represents the parallel compensation capacitance of the secondary side circuit, L p represents the coil of the primary side circuit, L s represents the coil of the secondary side circuit, C f1 represents the series compensation capacitance of the primary side circuit, C f2 represents the series compensation capacitance of the secondary side circuit.

[0062] As shown in Figure 1 , the present disclosure provides an optimization control method of a bidirectional underwater wireless charging system, comprising S11 to S16.

[0063] S11, the preset transmission power, the ratio parameter of the equivalent voltage phasor amplitude of the primary and secondary side circuits, and the phase difference parameter of the equivalent voltage phasor of the primary and secondary side circuits are adopted to represent the equivalent voltage phasor of the primary and secondary side circuits, and the equivalent voltage phasor representation of the primary and secondary side circuits is determined.

[0064] Wherein, the ratio parameter of the equivalent voltage phasor amplitude of the primary and secondary side circuits can be represented as λ, and the phase difference parameter of the equivalent voltage phasor of the primary and secondary side circuits can be represented as θ.

[0065] According to the preset transmission power, the inverse voltage of the primary side circuit and the inverse voltage of the secondary side circuit are set to have a λ 2 times relationship, the primary and secondary side phase shift angles are set to θ, and the equivalent voltage phasor amplitude of the primary and secondary side circuits is represented as:

[0066]

[0067] wherein U AB represents the effective value of the inverse voltage phasor of the primary side circuit, U ab represents the effective value of the inverse voltage phasor of the secondary side circuit, and P represents the preset transmission power.

[0068] Since the rated working power of the transmitting end and the receiving end of the bidirectional underwater wireless charging system may be different, based on the voltage withstand and current flow level of each element of the bidirectional underwater wireless charging system, the resonant network parameters of the primary and secondary sides, and the identified mutual inductance, the required preset transmission power is determined.

[0069] S12, the ratio of the equivalent voltage phasor amplitude of the primary and secondary side circuits, the phase difference value parameter of the equivalent voltage phasor of the primary and secondary side circuits are used to represent the parasitic loss and the synthesized eddy current electric field loss of the primary and secondary side circuits, and the total loss expression of the underwater wireless charging system is determined.

[0070] In a possible embodiment, S12, the ratio of the equivalent voltage phasor amplitude of the primary and secondary side circuits, the phase difference value parameter of the equivalent voltage phasor of the primary and secondary side circuits are used to represent the parasitic loss and the synthesized eddy current electric field loss of the primary and secondary side circuits, and the total loss expression of the underwater wireless charging system is determined, which can include S21 to S23.

[0071] S21, the ratio of the equivalent voltage phasor amplitude of the primary and secondary side circuits, the phase difference value parameter of the equivalent voltage phasor of the primary and secondary side circuits are used to represent the parasitic loss of the primary and secondary side circuits, and the parasitic loss expression of the primary and secondary side circuits is determined.

[0072] Among them, the current of each loop is first represented by the equivalent voltage phasor of the primary and secondary side circuits, and the current expression of each loop is determined.

[0073] As shown in Figure 2 According to the reference direction of the inverse voltage and current in Figure 2 , based on Kirchhoff's law, and ignoring the influence of the parasitic resistance of the resonant inductor, U AB = U AB ∠0°, U AB leads U ab by an angle of θ.

[0074] The functional relationship between the current of each loop and the equivalent voltage phasor of the primary and secondary side circuits in the double-sided LCC compensation network, i.e., the current expression of each loop, is as follows:

[0075]

[0076] Among them, I AB represents the inverse current phasor of the primary side circuit, I ab represents the inverse current phasor of the secondary side circuit, I p represents the current phasor flowing through the coil of the primary side circuit, I s represents the current phasor flowing through the coil of the secondary side circuit, and j represents the imaginary unit.

[0077] Therefore, the transmission power expression of the bidirectional underwater wireless charging system of the double-sided LCC compensation network is:

[0078]

[0079] Wherein, P represents the active power transmitted by the system, Q represents the reactive power transmitted by the system, U1 represents the voltage of the direct current power supply of the primary side circuit, and U2 represents the voltage of the direct current power supply of the secondary side circuit.

[0080] Secondly, according to the current representation of each loop and the total resistance representation of each loop, the parasitic loss representation of the primary and secondary side circuits is determined.

[0081] When the double-sided LCC compensation network is in the ZVS state, the parasitic loss of the bidirectional underwater wireless charging system, i.e. the parasitic loss representation of the primary and secondary side circuits, is:

[0082]

[0083] Wherein,

[0084] Wherein, P cir represents the parasitic loss of the primary and secondary side circuits, P loss,coil represents the loss caused by the coil resistance, P loss,L represents the loss caused by the parasitic resistance of the resonant inductance, P loss,RDSon represents the on-state loss of the MOSFET, R DSon represents the on-resistance of the MOSFET, R fL1 represents the internal resistance of the series compensation inductance L f1 of the primary side circuit, R fL2 represents the internal resistance of the series compensation inductance L f2 of the secondary side circuit.

[0085] Through the above technical solution, the parasitic loss of the primary and secondary side circuits can be represented as a function relationship expression related to the ratio parameter of the equivalent voltage phasor amplitude of the primary and secondary side circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary side circuits, which provides convenience for subsequent optimization of the equivalent voltage phasor of the primary and secondary side circuits.

[0086] S22, the ratio parameter of the equivalent voltage phasor amplitude of the primary and secondary side circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary side circuits are used to represent the synthesized eddy current field loss, and the synthesized eddy current field loss representation is determined.

[0087] For example, the coil current parameter of the primary and secondary side circuits is used to represent the synthesized eddy current field strength, and the synthesized eddy current field strength representation is determined.

[0088] Wherein, the coil current parameter of the primary and secondary side circuits is used to represent the primary side eddy current field strength and the secondary side eddy current field strength, and the primary side eddy current field strength representation and the secondary side eddy current field strength representation are determined.

[0089] Figure 3This is a schematic diagram illustrating the coil currents and induced electric fields of two sets of coils placed in parallel in cylindrical coordinates, according to an exemplary embodiment.

[0090] like Figure 3 As shown, let h be the distance between the two sets of coil planes.

[0091] like Figure 2 , Figure 3 As shown, the coil current i in the primary circuit p The electric field strength generated at any point in the seawater is The primary side eddy current electric field strength represents the coil current i in the secondary side circuit. s The electric field intensity generated at any point in seawater That is, the secondary side eddy current electric field strength, as shown in the following formula:

[0092]

[0093] Among them, E p E represents the intensity of the eddy current electric field on the primary side. s σ represents the secondary-side eddy current electric field strength, μ represents the magnetic permeability of seawater, σ represents the electrical conductivity of seawater, ε represents the dielectric constant of seawater, and a represents the dielectric constant of seawater. p a represents the average radius of the coil in the primary circuit. s N represents the average radius of the coil in the secondary circuit. p N represents the number of turns of the coil in the primary circuit. s I represents the number of turns of the coil in the secondary circuit. p I represents the effective value of the coil current in the primary circuit. s The value of the coil current in the secondary circuit is represented by γ, the integral variable is represented by J1(x), and the first-order Bessel function is represented by J1(x). The vector represents the unit direction of the electric field strength, and u represents an intermediate variable.

[0094] The intermediate variable of u is represented as:

[0095]

[0096] Based on the representations of the primary and secondary eddy current electric field strengths, the representation of the composite eddy current electric field strength is determined.

[0097]

[0098] in,

[0099]

[0100] Among them, E tot This represents the effective value of the combined eddy current electric field intensity.

[0101] According to the synthetic eddy current electric field intensity representation, the volume integral processing is performed on the preset eddy current loss area to determine a synthetic eddy current electric field loss representation.

[0102] The volume integral processing is performed on the electric field intensity of each point position in seawater on the preset eddy current loss area, and the synthetic eddy current electric field loss generated in the seawater area between the two groups of coils is represented as a function expression related to the ratio parameter of the equivalent voltage phase quantity amplitude of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phase quantity of the primary and secondary circuits by combining the above formula (2) and formula (3):

[0103]

[0104] wherein,

[0105] wherein, P eddy represents the synthetic eddy current electric field loss.

[0106] S23, the parasitic loss representation of the primary and secondary circuits and the synthetic eddy current electric field loss representation are summed to determine a total loss representation of the underwater wireless charging system.

[0107] The total loss representation of the underwater wireless charging system is:

[0108]

[0109] wherein, P loss represents the total loss representation of the underwater wireless charging system, P cir the parasitic loss of the primary and secondary circuits, P eddy represents the synthetic eddy current electric field loss.

[0110] S13, the total loss representation of the underwater wireless charging system is minimized to determine the optimized ratio of the equivalent voltage phase quantity amplitude of the primary and secondary circuits and the optimized phase difference of the equivalent voltage phase quantity of the primary and secondary circuits.

[0111] In a possible embodiment, S13, the total loss representation of the underwater wireless charging system is minimized to determine the optimized ratio of the equivalent voltage phase quantity amplitude of the primary and secondary circuits and the optimized phase difference of the equivalent voltage phase quantity of the primary and secondary circuits, can include S31 to S32.

[0112] S31, the total loss representation of the underwater wireless charging system is differentiated with respect to the ratio parameter of the equivalent voltage phase quantity amplitude of the primary and secondary circuits to determine the ratio of the equivalent voltage phase quantity amplitude of the primary and secondary circuits corresponding to the minimum value of the total loss of the underwater wireless charging system as the optimized ratio of the equivalent voltage phase quantity amplitude of the primary and secondary circuits.

[0113] S32, a derivative processing is performed on the phase difference value parameter of the equivalent voltage phase sequence of the primary and secondary side circuits, and the phase difference value of the equivalent voltage phase sequence of the primary and secondary side circuits corresponding to the minimum total loss of the underwater wireless charging system is determined as the optimized equivalent voltage phase difference value of the primary and secondary side circuits.

[0114] According to the above example, the derivative processing is performed on the ratio parameter λ of the equivalent voltage phase sequence amplitude of the primary and secondary side circuits and the phase difference value parameter θ of the equivalent voltage phase sequence of the primary and secondary side circuits according to the above formula (9), and λ op and θ op corresponding to the minimum total loss of the underwater wireless charging system are determined.

[0115]

[0116] wherein λ op represents the optimized ratio of the equivalent voltage phase sequence amplitude of the primary and secondary side circuits, and θ op represents the optimized phase difference value of the equivalent voltage phase sequence of the primary and secondary side circuits.

[0117] S14, according to the optimized ratio of the equivalent voltage phase sequence amplitude of the primary and secondary side circuits and the optimized phase difference value of the equivalent voltage phase sequence of the primary and secondary side circuits, and the equivalent voltage phase sequence representation of the primary and secondary side circuits, the optimized equivalent voltage phase sequence of the primary and secondary side circuits is determined.

[0118] According to the above example, the preset transmission power, the optimized ratio of the equivalent voltage phase sequence amplitude of the primary and secondary side circuits, and the optimized phase difference value of the equivalent voltage phase sequence of the primary and secondary side circuits are substituted into the equivalent voltage phase sequence representation of the primary and secondary side circuits, and the optimized equivalent voltage phase sequence of the primary and secondary side circuits is determined.

[0119] The above formula (10) is substituted into the above formula (2), and the optimized equivalent voltage phase sequence of the primary and secondary side circuits is determined.

[0120] S15, according to the optimized equivalent voltage vector of the primary and secondary side circuits and the preset internal and external phase shift angle, the optimized alternating voltage phase sequence of the primary side circuit and the optimized inverter voltage of the secondary side circuit are determined.

[0121] The parameters λ and θ defined in the present disclosure correspond one-to-one to the preset internal and external phase shift angle.

[0122] According to the above example, according to the preset internal and external phase shift angle, the optimized direct current voltage of the primary and secondary side circuits is inverted into alternating voltage, and the optimized alternating voltage phase sequence of the primary side circuit and the optimized alternating voltage phase sequence of the secondary side circuit are determined.

[0123] By the technical solution, the equivalent voltage phasor of the primary and secondary circuits of the bidirectional underwater wireless charging system is optimized and controlled by minimizing the total loss of the bidirectional underwater wireless charging system, and then the current distribution in the resonant network loop is optimized, the synthetic eddy current electric field excited by the primary and secondary coil currents in the seawater medium is reduced, the synthetic eddy current electric field loss and the parasitic loss of the circuit are reduced, the efficiency optimization of the bidirectional underwater wireless charging system is realized, the system efficiency reduction caused by the parameter asymmetry of the transmitting end and the receiving end is prevented, and the interoperability of the bidirectional underwater wireless charging system is improved.

[0124] In some possible embodiments, the optimization control method of the bidirectional underwater wireless charging system can further include S17.

[0125] S17, controlling the bidirectional underwater wireless charging system according to the optimized AC voltage phasor of the primary circuit and the optimized AC voltage phasor of the secondary circuit.

[0126] By adopting the optimized AC voltage phasor of the primary circuit and the optimized AC voltage phasor of the secondary circuit, the total loss of the bidirectional underwater wireless charging system is reduced, and the efficiency and interoperability of the bidirectional underwater wireless charging system are improved.

[0127] In a possible embodiment, the optimization control method of the bidirectional underwater wireless charging system can further include S18 to S19.

[0128] S18, sharing the parameter information of the primary circuit and the parameter information of the secondary circuit.

[0129] Before the mutual inductance identification of the primary circuit and the secondary circuit, the communication of the primary circuit and the secondary circuit can be established, and the necessary parameter information of the primary circuit and the secondary circuit, such as the rated working voltage, the resonant network parameter, the device voltage withstand level, and the element internal resistance, is shared.

[0130] S19, mutual inductance identification of the primary circuit and the secondary circuit.

[0131] The receiving end is short-circuited, and the inverter is normally operated to provide the necessary I p The other inverters work in the bypass state, and the equivalent circuit can be further simplified at this time, the mutual inductance is determined by the system parameters, the voltage of the primary side and the current of the secondary side, no additional hardware is needed, the cost is low, and the efficiency is high.

[0132] The steps S18 to S19 can be performed before the step S11 of the present disclosure.

[0133] In a possible embodiment, the parameters of the bidirectional underwater wireless charging system are set as follows:

[0134] DC voltage of primary side circuit: 150 V;

[0135] DC voltage of secondary side circuit: 150 V;

[0136] Operating frequency: 85500 Hz;

[0137] Self-inductance L of coil of primary side circuit p : 118.3 μH;

[0138] Self-inductance L of coil of secondary side circuit s : 92.2 μH;

[0139] Mutual inductance M between coil L of primary side circuit p and coil L of secondary side circuit s : 23.2 μH;

[0140] Series compensation inductance L of primary side circuit f1 : 14.8 μH;

[0141] Series compensation inductance L of secondary side circuit f2 : 45.9 μH;

[0142] Parallel compensation capacitance C of primary side circuit p1 : 231.0 nF;

[0143] Parallel compensation capacitance C of secondary side circuit p2 : 75.8 nF;

[0144] Series compensation capacitance C of primary side circuit f1 : 33.1 nF;

[0145] Series compensation capacitance C of secondary side circuit f2 : 74.5 nF;

[0146] Number of turns N of coil of primary side circuit p : 10;

[0147] Number of turns N of coil of secondary side circuit s : 10;

[0148] Radius a of coil of primary side circuit p : 30 cm;

[0149] Radius a of coil of secondary side circuit s : 20 cm;

[0150] Distance h between coil of primary side circuit and coil of secondary side circuit: 15 cm;

[0151] Internal resistance of coil L of primary side circuit p : 0.15 Ω;

[0152] The coil L of the secondary side circuit s The internal resistance of the primary side circuit: 0.10Ω;

[0153] The internal resistance of the series compensation inductance of the primary side circuit R fL1 : 0.03Ω;

[0154] The internal resistance of the series compensation inductance of the secondary side circuit R fL2 : 0.03Ω;

[0155] The on-state internal resistance R of the MOSFET DSon : 0.01Ω.

[0156] Under the above parameter settings, the parameters λ and θ are scanned in the preset range to determine the numerical relationship between the system transmission power, the circuit parasitic loss, the eddy current loss, and the system efficiency and λ and θ.

[0157] Figure 4 is a schematic diagram of the relationship between the transmission power, the circuit parasitic loss, the synthetic eddy current electric field loss, and the system efficiency and the ratio parameter λ of the equivalent voltage phasor amplitude of the primary and secondary side circuits, and the phase difference value parameter θ of the equivalent voltage of the primary and secondary side circuits, according to an exemplary embodiment.

[0158] Figure 4 (a) represents a schematic diagram of the relationship between the transmission power and the parameters λ and θ; Figure 4 (b) represents a schematic diagram of the relationship between the circuit parasitic loss and the parameters λ and θ; Figure 4 (c) represents a schematic diagram of the relationship between the circuit synthetic eddy current electric field loss and the parameters λ and θ; Figure 4 (d) represents a schematic diagram of the relationship between the system efficiency and the parameters λ and θ.

[0159] As Figure 4 shown, without adjusting the voltage phasor, the synthetic eddy current electric field loss is 108.8W, the circuit parasitic loss is 155.17W, and the system efficiency is 81.4%. When λ is scanned in the preset range, the system loss and efficiency change dramatically.

[0160] When λ=0.48 and θ=140°, the synthetic eddy current electric field loss of the bidirectional underwater wireless charging system is the lowest, being 26.60W.

[0161] When λ=0.60 and θ=90°, the circuit parasitic loss of the bidirectional underwater wireless charging system is the smallest, being 111.94W.

[0162] When λ=0.52 and θ=110°, the transmission efficiency of the bidirectional underwater wireless charging system is the highest, reaching 88.3%, which is increased by 6.9% compared with that without adjustment.

[0163] Figure 5is a schematic diagram of the coil current and the eddy current field at any point position in the coil of the system before and after optimization of the equivalent voltage phasor of the primary and secondary side circuit according to an example embodiment.

[0164] wherein, Figure 5 (a) represents a schematic diagram of the coil current and the eddy current field at any point position in the system before optimization of the equivalent voltage phasor of the primary and secondary side circuit, Figure 5 (b) represents a schematic diagram of the coil current and the eddy current field at any point position in the system after optimization of the equivalent voltage phasor of the primary and secondary side circuit.

[0165] As Figure 5 shown, the adjustment of the voltage phasor causes changes in the amplitude and angle of the coil current phasor, and the amplitude of the synthesized eddy current field after adjustment of the voltage phasor is significantly reduced, which can reduce the synthesized eddy current field loss and improve the efficiency of the bidirectional underwater wireless charging system.

[0166] Figure 6 is a flowchart of an optimization control device of a bidirectional underwater wireless charging system according to an example embodiment.

[0167] Based on the same concept, the disclosure also provides an optimization control device of a bidirectional underwater wireless charging system, as Figure 6 shown, comprising: a first determination module 110, a loss determination module 120, a second determination module 130, a first optimization module 140, and a second optimization module 150.

[0168] The first determination module 110 is configured to determine the equivalent voltage phasor of the primary and secondary side circuit by using a preset ratio parameter of the transmission power and the equivalent voltage phasor amplitude of the primary and secondary side circuit, and a phase difference parameter of the equivalent voltage phasor of the primary and secondary side circuit.

[0169] The loss determination module 120 is configured to determine the total loss of the underwater wireless charging system by using the ratio parameter of the equivalent voltage phasor amplitude of the primary and secondary side circuit and the phase difference parameter of the equivalent voltage phasor of the primary and secondary side circuit to represent the parasitic loss and the synthesized eddy current field loss of the primary and secondary side circuit.

[0170] The second determination module 130 is configured to minimize the total loss of the underwater wireless charging system to determine the optimized ratio of the equivalent voltage phasor amplitude of the primary and secondary side circuit and the optimized phase difference of the equivalent voltage phasor of the primary and secondary side circuit.

[0171] The first optimization module 140 is configured to determine the equivalent voltage phase quantity of the optimized primary-secondary side circuit according to the ratio of the equivalent voltage phase quantity amplitudes of the optimized primary-secondary side circuit, the phase difference of the equivalent voltage phase quantities of the optimized primary-secondary side circuit, and the equivalent voltage phase quantity representation of the primary-secondary side circuit.

[0172] The second optimization module 150 is configured to determine the AC voltage phase quantity of the optimized primary side circuit and the AC voltage phase quantity of the optimized secondary side circuit according to the equivalent voltage vector of the optimized primary-secondary side circuit and the preset internal-external phase shift angle.

[0173] By the above technical solution, the equivalent voltage phase quantity of the primary-secondary side circuit of the bidirectional underwater wireless charging system is optimized and controlled by minimizing the total loss representation of the bidirectional underwater wireless charging system, the current distribution in the resonant network loop is further optimized, the synthetic eddy current electric field excited by the primary-secondary side coil current in the seawater medium is reduced, the synthetic eddy current electric field loss and the parasitic loss of the circuit are reduced, the efficiency optimization of the bidirectional underwater wireless charging system is realized, the system efficiency reduction caused by the parameter asymmetry of the transmitting end and the receiving end is prevented, and the interoperability of the bidirectional underwater wireless charging system is improved.

[0174] As to the embodiments of the above system, the specific manner in which the various modules perform operations has been described in detail in the embodiments of the method, and will not be described in detail here.

[0175] Based on the same idea, in another embodiment of the present disclosure, an electronic device is also provided, which includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and the processor is configured to execute the optimization control method of the bidirectional underwater wireless charging system when executing the program.

[0176] Optionally, the memory is configured to store a program; the memory can include volatile memory (e.g., random access memory (RAM), such as static random access memory (SRAM), Double Data Rate synchronous dynamic random access memory (DDR SDRAM), and the like) or non-volatile memory (e.g., flash memory). The memory is configured to store computer programs (e.g., application programs, functional modules, and the like for implementing the above-described methods), computer instructions, and the like. The computer programs, computer instructions, and the like described above can be stored in one or more memories in a partitioned manner. Moreover, the computer programs, computer instructions, and the like described above can be invoked by the processor.

[0177] The computer programs, computer instructions, and the like described above can be stored in one or more memories in a partitioned manner. Moreover, the computer programs, computer instructions, and the like described above can be invoked by the processor.

[0178] The processor is configured to execute the computer programs stored in the memory to implement each step in the methods described above in the embodiments. Details can be referred to the related descriptions in the method embodiments above.

[0179] The processor and the memory can be independent structures or integrated structures. When the processor and the memory are independent structures, the memory and the processor can be coupled and connected through a bus.

[0180] In the embodiments of the present disclosure, a non-transitory computer-readable storage medium is also provided, which stores a computer program. The computer program is executed by a processor to implement the steps of the optimization control method of the bidirectional underwater wireless charging system in any of the above-described embodiments.

[0181] Those skilled in the art will understand that the embodiments of the present disclosure can be provided as a method, a system, or a computer program product. Therefore, the present disclosure can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present disclosure can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage media, and the like) containing computer-usable program code.

[0182] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0183] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0184] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0185] While the preferred embodiments of the present disclosure have been described, additional variations and modifications can be employed by those skilled in the art once armed with the concepts reflected in the preferred embodiments without departing from the scope of the present disclosure. Consequently, the appended claims are intended to embrace all such additional variations and modifications as fall within the scope of the present disclosure.

[0186] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. An optimal control method of a bidirectional underwater wireless charging system, characterized in that, The method comprises the following steps: characterizing the equivalent voltage phasor of the primary and secondary circuits by using a preset transmission power, a ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits, and a phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining an equivalent voltage phasor representation of the primary and secondary circuits; characterizing the parasitic loss and the synthetic eddy current field loss of the primary and secondary circuits by using the ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining a total loss representation of the underwater wireless charging system; performing minimization processing on the total loss representation of the underwater wireless charging system, and determining an optimized ratio of equivalent voltage phasor amplitudes of the primary and secondary circuits and an optimized phase difference of the equivalent voltage phasor of the primary and secondary circuits; determining an optimized equivalent voltage phasor of the primary and secondary circuits according to the optimized ratio of equivalent voltage phasor amplitudes of the primary and secondary circuits, the optimized phase difference of the equivalent voltage phasor of the primary and secondary circuits, and the equivalent voltage phasor representation of the primary and secondary circuits; determining an optimized alternating voltage phasor of the primary circuit and an optimized alternating voltage phasor of the secondary circuit according to the optimized equivalent voltage phasor of the primary and secondary circuits and a preset internal and external phase shift angle.

2. The method of claim 1, wherein, The method further comprises the following steps: controlling the bidirectional underwater wireless charging system according to the optimized alternating voltage phasor of the primary circuit and the optimized alternating voltage phasor of the secondary circuit.

3. The method of claim 1, wherein, The step of characterizing the parasitic loss and the synthetic eddy current field loss of the primary and secondary circuits by using the ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining a total loss representation of the underwater wireless charging system comprises the following steps: characterizing the parasitic loss of the primary and secondary circuits by using the ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining a parasitic loss representation of the primary and secondary circuits; characterizing the synthetic eddy current field loss by using the ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining a synthetic eddy current field loss representation; performing summation processing on the parasitic loss representation of the primary and secondary circuits and the synthetic eddy current field loss representation, and determining the total loss representation of the underwater wireless charging system.

4. The method of claim 3, wherein, The step of characterizing the parasitic loss of the primary and secondary circuits by using the ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining a parasitic loss representation of the primary and secondary circuits comprises the following steps: characterizing a current of each loop of the primary and secondary circuits by using the equivalent voltage phasor representation of the primary and secondary circuits, and determining a current representation of each loop; determining the parasitic loss representation of the primary and secondary circuits according to the current representation of each loop and a total resistance value representation of each loop.

5. The method of claim 3, wherein, The step of characterizing the synthetic eddy current field loss by using the ratio parameter of equivalent voltage phasor amplitudes of the primary and secondary circuits and the phase difference parameter of the equivalent voltage phasor of the primary and secondary circuits, and determining a synthetic eddy current field loss representation comprises the following steps: The coil current parameter of the primary-secondary side circuit is used to represent the synthesized eddy current electric field intensity, and the synthesized eddy current electric field intensity representation is determined. According to the synthesized eddy current electric field intensity representation, the volume integral processing is performed on the preset eddy current loss area, and the synthesized eddy current electric field loss representation is determined.

6. The method of claim 5, wherein, The coil current parameter of the primary-secondary side circuit is used to represent the synthesized eddy current electric field intensity representation, and the synthesized eddy current electric field intensity representation is determined. The coil current parameter of the primary-secondary side circuit is used to represent the primary side eddy current electric field intensity and the secondary side eddy current electric field intensity, and the primary side eddy current electric field intensity representation and the secondary side eddy current electric field intensity representation are determined. According to the primary side eddy current electric field intensity representation and the secondary side eddy current electric field intensity representation, the synthesized eddy current electric field intensity representation is determined.

7. The method of claim 1, wherein, The total loss representation of the underwater wireless charging system is minimized, and the ratio of the equivalent voltage phase quantity amplitude of the optimized primary-secondary side circuit and the phase difference value of the equivalent voltage phase quantity of the optimized primary-secondary side circuit are determined. The total loss representation of the underwater wireless charging system is minimized, and the ratio of the equivalent voltage phase quantity amplitude of the optimized primary-secondary side circuit and the phase difference value of the equivalent voltage phase quantity of the optimized primary-secondary side circuit are determined. The total loss representation of the underwater wireless charging system is minimized, and the ratio of the equivalent voltage phase quantity amplitude of the optimized primary-secondary side circuit and the phase difference value of the equivalent voltage phase quantity of the optimized primary-secondary side circuit are determined.

8. The method of claim 1, wherein, The total loss representation of the underwater wireless charging system is minimized, and the ratio of the equivalent voltage phase quantity amplitude of the optimized primary-secondary side circuit and the phase difference value of the equivalent voltage phase quantity of the optimized primary-secondary side circuit are determined. The method further comprises:

9. The method of claim 1, wherein, The parameter information of the primary side circuit and the parameter information of the secondary side circuit are shared; The mutual inductance of the primary side circuit and the secondary side circuit is identified. Comprise:

10. An optimal control device of a bidirectional underwater wireless charging system, characterized by, The first determination module is used to represent the equivalent voltage phase quantity of the primary-secondary side circuit by using the preset transmission power, the ratio of the equivalent voltage phase quantity amplitude of the primary-secondary side circuit, and the phase difference value of the equivalent voltage phase quantity of the primary-secondary side circuit, and to determine the equivalent voltage phase quantity representation of the primary-secondary side circuit. The loss determination module is used to represent the parasitic loss and the synthesized eddy current electric field loss of the primary-secondary side circuit by using the ratio of the equivalent voltage phase quantity amplitude of the primary-secondary side circuit and the phase difference value of the equivalent voltage phase quantity of the primary-secondary side circuit, and to determine the total loss representation of the underwater wireless charging system. ​ The second determining module is configured to minimize the underwater wireless charging system total loss representation, and determine an optimized ratio of equivalent voltage phasor amplitudes of the primary and secondary circuits and an optimized phase difference value of the equivalent voltage phasors of the primary and secondary circuits. The first optimization module is configured to determine an optimized equivalent voltage phasor of the primary and secondary circuits according to the optimized ratio of equivalent voltage phasor amplitudes of the primary and secondary circuits, the optimized phase difference value of the equivalent voltage phasors of the primary and secondary circuits, and the equivalent voltage phasor representation of the primary and secondary circuits. The second optimization module is configured to determine an optimized alternating current voltage phasor of the primary circuit and an optimized alternating current voltage phasor of the secondary circuit according to the optimized equivalent voltage vector of the primary and secondary circuits and preset internal and external phase shift angles.

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