Underwater magnetic coupling resonant wireless power transmission voltage stabilization control system and method

Abstract

The invention relates to the technical field of wireless charging, in particular to an underwater magnetic coupling resonant wireless power transmission voltage stabilization control system and method, and the system comprises a transmitting end which comprises a power supply, an inverter circuit, a transmitting end compensation network and an array type orthogonal magnetic coupling device, and the array type orthogonal magnetic coupling device comprises four DD type coils, the DD type coils are alternately wound to generate a horizontal magnetic field and a vertical magnetic field; the receiving end comprises a biorthogonal coil, a receiving end compensation network, a rectification filtering module and a converter; the biorthogonal coil receives energy of the horizontal magnetic field and the vertical magnetic field; the linear active disturbance rejection control module comprises an extended state observer and a linear feedback control rate, the extended state observer is used for estimating the total disturbance of the system in real time and performing feed-forward compensation, and the linear feedback control rate realizes voltage stabilization by adjusting the duty ratio of the converter. The system adapts to a deep sea complex environment, and the cruising ability of the AUV is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless charging, in particular to an underwater magnetic coupling resonant wireless power transmission voltage stabilization control system and method. BACKGROUND

[0002] Autonomous Underwater Vehicles (AUVs) are increasingly important in modern ocean resource exploitation and research. These unmanned underwater devices can perform tasks in extreme environments, collect data, monitor the environment, and even participate in the exploitation of deep-sea mineral resources. As global demand for renewable energy and ocean resource development increases, the application scenarios of AUVs are gradually expanding, covering scientific research, environmental protection, oil and gas exploration, and ocean mineral development.

[0003] However, the existing underwater charging method of AUVs still faces many challenges, mainly due to the complexity of the underwater environment and related technical constraints. On the one hand, the pressure, temperature, and salinity changes in the underwater environment can significantly affect charging efficiency and device reliability. Deep-sea high pressure and low temperature conditions can cause electrical equipment performance to decline, and even malfunction. On the other hand, the underwater charging process places extremely high demands on the stability and reliability of electrical connections. In practical applications, slight displacement of the AUV body, water flow disturbance, or changes in seabed topography can cause poor contact of the charging interface, leading to voltage instability, charging interruption, and even equipment damage. In addition, charging efficiency is also one of the key factors affecting the efficiency of AUV operations. Due to the problems of limited charging power and lagging control strategy in existing underwater charging systems, the charging time is long, significantly shortening the operation time of AUVs, and thus limiting their task execution frequency and work cycle, making it difficult to meet the current requirements for high frequency and autonomous endurance of ocean operations.

[0004] Based on the above problems, the present application proposes an underwater magnetic coupling resonant wireless power transmission voltage stabilization control system and method. SUMMARY

[0005] To solve the technical problems of the dependence on precise docking and poor environmental adaptability of traditional underwater charging technology, an underwater magnetic coupling resonant wireless power transmission voltage stabilization control system and method are provided. The system transmission end is designed as a side-by-side DD coil array floating on the water surface, which can generate vertical and horizontal magnetic fields to adapt to the offset of the vehicle due to wave disturbance. The receiving end adopts a compact design and is installed on the top of the vehicle, allowing efficient charging when the vehicle floats to the water surface. The design goal of the system is to achieve omnidirectional charging with free positioning, without the need for precise alignment. Only when the vehicle floats to the water surface can charging be performed, improving the practicality and robustness of the system.

[0006] The technical means adopted by the present application are as follows:

[0007] An underwater magnetic coupling resonant wireless power transmission voltage stabilization control system comprises:

[0008] A transmitting end comprises a power supply, an inverter circuit, a transmitting end compensation network and an array type orthogonal magnetic coupling device, the array type orthogonal magnetic coupling device comprises four DD type coils, the DD type coils are alternately wound to generate a horizontal magnetic field and a vertical magnetic field;

[0009] A receiving end comprises a double orthogonal coil, a receiving end compensation network, a rectification and filtering module and a DC-DC converter, the double orthogonal coil receives energy of the horizontal magnetic field and the vertical magnetic field, and the DC-DC converter comprises a linear active disturbance rejection control module;

[0010] The linear active disturbance rejection control module comprises an extended state observer and a linear feedback control rate, the extended state observer is used for real-time estimation of total disturbance of the system and feedforward compensation, and the linear feedback control rate realizes voltage stabilization by adjusting a duty cycle of the converter.

[0011] Further, the double orthogonal coil is integrated with a ferrite core.

[0012] Further, the transmitting end compensation network comprises a transmitting end compensation capacitor, a compensation DC blocking capacitor and a transmitting end coil equivalent internal resistance, the transmitting end compensation capacitor is connected in parallel with the compensation DC blocking capacitor, a transmitting end coil inductance and the transmitting end coil equivalent internal resistance connected in series;

[0013] The receiving end compensation network comprises a transmitting end compensation capacitor and a receiving end coil equivalent internal resistance, the transmitting end compensation capacitor, a receiving end coil inductance and the receiving end coil equivalent internal resistance are connected in series.

[0014] Further, the double orthogonal coil comprises two rectangular coils arranged orthogonally, the rectangular coils pick up magnetic flux components in parallel and vertical directions and ensure independence of energy reception through decoupling design.

[0015] Further, in the four DD type coils, winding modes of adjacent coils are opposite, and the four DD type coils are connected in series.

[0016] Further, the extended state observer adopts linearization design, and a calculation formula of a gain parameter of the extended state observer is as follows:

[0017] β1=3ω0

[0018] β2=3ω0 2

[0019] β3=ω0 3

[0020] Where β1 is the first gain parameter, β2 is the second gain parameter, β3 is the third gain parameter, and ω0 is the bandwidth of the extended state observer.

[0021] A method for controlling voltage stabilization of underwater magnetically coupled resonant wireless power transmission is provided, which is based on the above-mentioned voltage stabilization control system of underwater magnetically coupled resonant wireless power transmission, and comprises the following steps:

[0022] After the system is started, the array-type orthogonal magnetic coupling device generates complementary horizontal and vertical magnetic fields through the power supply, inverter circuit, and transmitter compensation network. The horizontal and vertical magnetic fields can cover the offset range of the underwater vehicle.

[0023] The dual orthogonal coils pick up energy from the horizontal and vertical magnetic fields. The dual orthogonal coils operate based on a receiving-end compensation network. The energy from the horizontal and vertical magnetic fields is converted into direct current through a rectifier and filter module.

[0024] The linear active disturbance rejection control module is used to estimate the total disturbance of the system in real time and perform feedforward compensation through an extended state observer, and on the other hand, to achieve voltage stabilization by adjusting the duty cycle of the converter through linear feedback vacancy rate.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The compensation network used in this invention adopts an LCC-S type compensation network. The output power of the LCC-S compensation network exhibits better stability characteristics with changes in mutual inductance and better anti-drift performance. The LCC-S type compensation network is suitable for medium- and long-distance wireless power transmission, can provide better load adaptability and stability, and is suitable for application scenarios requiring high flexibility and long-distance transmission.

[0027] 2. The transmitting coil of the present invention utilizes four identical coils, arranged on the same plane and of equal size. Each coil has a different winding direction, and the four coils are connected in series from left to right and driven by a single excitation. The receiving coil consists of two receivers to improve the system's energy transmission efficiency. Each receiving coil consists of a rectangular magnetic core and two orthogonal receiving coils, enabling them to effectively pick up parallel and perpendicular magnetic flux components, respectively.

[0028] 3. The linear active disturbance rejection control (LADRC) adopted in the present invention is a special form of ADRC. It replaces the nonlinear part in the traditional ADRC with the linear state observer (LESO) and the linear control law, making it simpler and less computationally intensive in engineering implementation. While retaining the advantages of the original ADRC, it reduces the use of nonlinear functions. By linearizing the ESO and NLSEF, the control system structure of the LADRC is greatly simplified, which greatly facilitates parameter tuning and theoretical analysis.

[0029] Based on the above reasons, the present invention can be widely promoted in fields such as wireless charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 This is a system structure diagram of the present invention.

[0032] Figure 2 Schematic diagram of the structure of the aircraft of the present invention.

[0033] Figure 3 This is a schematic diagram of the physical structure of the transmitting coil of the present invention.

[0034] Figure 4 This is a schematic diagram of the physical structure of the receiving coil of the present invention.

[0035] Figure 5 This is a circuit theory model diagram of the LCC-S type magnetic coupling mechanism of the present invention.

[0036] Figure 6 This is a second-order ADRC control structure diagram of the present invention.

[0037] Figure 7 This is a second-order LADRC control structure diagram of the system of the present invention. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0040] like Figures 1-7 As shown, the present invention provides an underwater magnetic coupling resonant wireless power transmission voltage stabilization control system.

[0041] like Figure 1 As shown, the system includes:

[0042] The transmitter includes a power supply I, an inverter circuit, a transmitter compensation network II, and an array-type orthogonal magnetic coupling device III. The array-type orthogonal magnetic coupling device includes four DD-type coils, which are alternately wound to generate horizontal and vertical magnetic fields. The receiver includes dual orthogonal coils, a receiver compensation network II, a rectifier and filter module IV, and a converter V. The dual orthogonal coils receive energy from the horizontal and vertical magnetic fields. The linear active disturbance rejection control module includes an extended state observer and a linear feedback control rate. The extended state observer is used to estimate the total system disturbance in real time and perform feedforward compensation. The linear feedback control rate adjusts the converter's duty cycle to achieve voltage regulation.

[0043] Specifically, the inverter circuit uses a full-bridge topology to meet the system's requirements for power transmission capability and output voltage stability at an 85kHz operating frequency. The full-bridge inverter circuit consists of four power switching devices, and the output voltage amplitude can reach twice the input DC voltage. It is suitable for high-power application scenarios, and can reduce switching losses and improve system efficiency through zero voltage switching (ZVS) or zero current switching (ZCS) technology. Compared with the half-bridge inverter circuit, which only uses two power switching devices and relies on a voltage divider capacitor to form a midpoint potential, although it can simplify the drive circuit, reduce costs and control difficulty, its output voltage is only half of the input DC voltage, the power carrying capacity is limited, and the matching accuracy of the voltage divider capacitor is high, which can easily affect the output voltage stability. Taking all the above factors into consideration, the full-bridge inverter circuit was finally selected to improve energy transmission efficiency and enhance system load adaptability.

[0044] As a preferred embodiment of the present invention, the converter is a DC-DC converter.

[0045] The working principle of the system is as follows: the DC signal U DC The high-frequency inverter converts the signal into a high-frequency AC signal. The resonant circuit on the primary side drives the transmitting coil, which converts the high-frequency signal into a high-frequency alternating magnetic field. The receiving coil induces a current in the alternating magnetic field, completing wireless energy transmission from the primary side to the secondary side. The high-frequency current induced by the receiving coil is filtered by the secondary-side resonant capacitor and converted to DC power by a rectifier to power the load. Because the output voltage U0 and current I0 of the underwater wireless power transmission system are affected by changes in mutual inductance and load, they must be monitored in real time and fed back to the controller. The controller determines the system output mode based on the current voltage and current and adjusts the MOSFET drive signal, thereby adjusting the duty cycle D of the DC-DC converter. This ensures precise control of the system's output voltage and current, ensuring stable power supply.

[0046] As a preferred embodiment of the present invention, the transmitter compensation network includes a transmitter compensation capacitor, a compensation blocking capacitor and an equivalent internal resistance of the transmitter coil. The transmitter compensation capacitor is connected in parallel with the series-connected compensation blocking capacitor, the transmitter coil inductor and the transmitter coil equivalent internal resistance to form an LCC type resonant compensation network. The receiver compensation network includes a transmitter compensation capacitor and an equivalent internal resistance of the receiver coil. The transmitter compensation capacitor, the receiver coil inductor and the receiver coil equivalent internal resistance are connected in series in sequence to form an S-type resonant compensation network. The LCC type resonant compensation network at the transmitter and the S-type resonant compensation network at the receiver together constitute an LCC-S type compensation topology, which achieves a constant current output characteristic through parameter tuning and reduces the impact of load fluctuations and coupling offsets on the system output.

[0047] like Figure 1 The circuit shown includes: DC input voltage source UDC Q1 to Q4 are four N-type MOS tubes, forming a full-bridge inverter circuit; the transmitter compensation network consists of a compensation inductor L f 、A transmitter parallel capacitor C f and a transmitter-side series capacitor C p , which is composed of a series inductor, a parallel capacitor, and a series capacitor; the equivalent internal resistance of the transmitting coil R P and the inductor L P ; The receiving end includes the equivalent internal resistance R of the dual orthogonal coil S1 and R S2 And its inductance L S1 and L S2 ; The compensation network at the receiving end consists of a series capacitor C S1 and C S2 Composition: Input filter capacitor C1, output filter capacitor C2, main switch tube S1 and freewheeling diode D1 together form the DC-DC converter part; M ps1 、M ps2 are the mutual inductances between the transmitting coil and the receiving coil respectively; the control part includes a PWM modulator, a PID controller, and a linear active disturbance rejection controller LADRC (Linear Active Disturbance Rejection Control).

[0048] like Figure 2 As shown, this embodiment provides a contactless wireless charging system for an autonomous underwater vehicle (AUV), the structure of which includes a plurality of transmitting coils arranged on a charging platform and a receiving coil integrated on the AUV body. The transmitting coil adopts a rectangular planar structure and is arranged at intervals above the predetermined docking area of ​​the AUV to generate an alternating magnetic field during the charging process. The receiving coil is fixedly arranged at a corresponding position on the top of the AUV body to induce electrical energy in the alternating magnetic field and complete energy reception and conversion through a rectifier circuit to achieve contactless and efficient charging of the AUV in an underwater environment. This structure has the advantages of flexible docking, strong anti-drift capability and high adaptability, and is suitable for energy replenishment needs in complex underwater operating environments.

[0049] like Figure 3The transmitter coil shown includes four identical coils (A, B, C, and D), all arranged on the same plane and of equal size. Each coil is wound in a different direction: coils A and C are wound clockwise, while coils B and D are wound counterclockwise. The four coils are connected in series from left to right and driven by a single excitation. The number of transmitter coils can be adjusted based on specific needs. Increasing the number of coils can effectively improve system stability and energy transfer efficiency, especially when the system requires higher anti-offset capabilities. Specifically, parallel and perpendicular magnetic fields are simultaneously generated above each pair of adjacent coils. This magnetic field interaction enhances the coupling effect between the coils, thereby improving the propagation of the magnetic field. The coupling between coils A and B, B and C, and C and D enables these coils to work together, improving energy transfer efficiency and reliability.

[0050] like Figure 4 The receiving coil shown consists of two receivers to improve the system's energy transfer efficiency. When the system's transmit power requirements are low, a single receiver suffices. Each receiving coil consists of a rectangular magnetic core and two orthogonal receiving coils: receiving coil a and receiving coil b. The cross-section of receiving coil a is parallel to the transmitting plane, while the cross-section of receiving coil b is perpendicular to the transmitting plane. This allows the two receiving coils to effectively pick up the parallel and perpendicular magnetic flux components, respectively. Furthermore, the two receiving coils exhibit good decoupling characteristics. This design is particularly suitable for underwater vehicles, where volume and space are often limited. Compact receiving coils enable efficient energy reception without increasing the system's size.

[0051] like Figure 5 In the circuit theory model structure diagram of the LCC-S type magnetic coupling mechanism shown in the figure, U S is the voltage of the high-frequency AC power supply; R p 、R s1 、R s2 are the equivalent internal resistances of the transmitting and receiving coils, L p , L s1 , L s2 are the inductance of the transmitting and receiving coils, C f 、C s1 、C s2 are the compensation capacitors at the transmitting and receiving ends respectively; R0 is the equivalent internal resistance of the compensation inductor, L f To compensate for the inductance, C p To compensate for the DC blocking capacitor, M ps1 、M ps2 are the mutual inductances between the transmitting coil and the receiving coil; R L is the load resistance on the receiving side; I p , I sI in are the currents flowing through the transmitting coil and the receiving coil, respectively, I p s1 s2 = R

[0052]

[0053] where C f , C s1 , C s2 are the compensation capacitances at the transmitting end and the receiving end, respectively, C f is the compensation capacitance at the transmitting end, ω is the angular frequency of the system, jωL p , jωL s1 , jωL s2 are the equivalent inductances at the transmitting end and the receiving end, respectively, L f is the compensation inductance, C p is the compensation DC blocking capacitor.

[0054] According to Kirchhoff's voltage law, the output voltage U L satisfies:

[0055]

[0056] where M ps1 , M ps2 are the mutual inductances between the transmitting coil and the receiving coil, U S is the voltage of the high-frequency AC power supply.

[0057] The output power P0 of the system is:

[0058]

[0059] where R L is the load resistance at the receiving side.

[0060] In this embodiment, the novel magnetic coupling structure is realized by arranging two receiving coils in each receiving unit, which are orthogonally distributed and correspond to the mutual inductances M ps1 and M ps2 ​​The distribution is in a sinusoidal function relationship. Since the two receiving coils are orthogonal to each other in space, their output characteristics are complementary, which can achieve the superposition of voltage UL, thereby maintaining stable output under different offset conditions. Compared with the traditional single receiving coil coupling structure, when there are changes in axial distance, radial offset or angular offset, the mutual inductance in the traditional structure is prone to violent fluctuations, resulting in a significant decrease in energy transmission efficiency. However, with the new magnetic coupling structure of the present application, even under axial offset conditions, the overall mutual inductance M can still fluctuate within a certain range, thereby achieving relatively stable energy transmission and significantly improving the system's anti-offset capability and robustness.

[0061] like Figure 6 The ADRC control structure shown in Figure 1 shows an ADRC controller consisting of three main components: a tracking differentiator (TD), an extended state observer (ESO), and a nonlinear error feedback controller (NLSEF). The TD takes the differential of the input signal and effectively reduces the overshoot of the output signal by introducing a transient process. The ESO expands the system's unknown disturbance into a new state. An internal algorithm estimates the system state and unknown disturbance in real time, and then uses the NLSEF for error feedback control, ensuring stable controller operation.

[0062] In the ADRC control block diagram, v is the target set value, y is the actual output of the system (controlled variable), and ω is the external disturbance; the tracking differentiator TD generates a smooth reference trajectory and outputs a tracking signal V1 and a differential signal V2; the extended state observer ESO estimates the system state and outputs a controlled variable estimate Z1, a controlled variable differential estimate Z2, and an extended state variable Z3; the tracking position error e1 and the tracking velocity error e2 are input into the nonlinear error feedback control rate NLSEF to generate the initial controlled variable u0; finally, the disturbance dynamic compensation is achieved through the control variable u, and the drive system achieves highly robust target tracking.

[0063] like Figure 7 The second-order LADRC control structure diagram shown in FIG replaces the nonlinear part of the traditional ADRC with a linear state observer (LESO) and a linear control law, making it simpler and less computationally intensive in engineering implementation.

[0064] Figure 7 This is the second-order LADRC control structure diagram. While retaining the original ADRC advantages, it reduces the use of nonlinear functions and greatly simplifies the control system structure of LADRC by linearizing ESO and NLSEF. refis the target setting value, y is the actual output of the system (controlled variable), and ω is the external disturbance; the linear extended state observer LESO outputs the controlled variable observation value Z1, the controlled variable differential observation value Z2 and the system total disturbance estimate Z3; the linear state error feedback LSEF is based on Z1, Z2 and U ref The error generates the control quantity u0, I / b0 represents the gain compensation link, and finally the disturbance dynamic compensation is achieved through the control quantity u. For the LADRC controller, consider a second-order pure integral system with external disturbances, and its state space model can be described as:

[0065]

[0066] Where y is the output signal of the system, ω is the external disturbance, u is the input control signal, t is the time-varying state of the system, b is the system gain coefficient, and f(y, ω, t) is the total disturbance caused by the external disturbance and the internal uncertainty of the system. The state of the system is defined as , then the state space equation of the system is expressed as:

[0067]

[0068] Where x1 is the first-order derivative of the system's output signal, x2 is the second-order derivative of the system's output signal, and h is the sum of all unknown disturbances in the system.

[0069] In this model, the disturbance f affects the dynamic behavior of the system and cannot be measured directly. To estimate the unknown disturbance, an extended state observer (LESO) is used. The design of LESO is as follows:

[0070]

[0071] Among them, β1 is the first gain parameter, β2 is the second gain parameter, and β3 is the third gain parameter, which is used to adjust the estimation accuracy of the disturbance f. In this paper, β1=3ω0,β2=3ω0 2 , β3=ω0 3 , ω0 is the bandwidth of the extended state observer. Then the control input u of the system can be designed as:

[0072]

[0073] The reference control quantity u0 can be expressed as:

[0074]

[0075] Among them, r is the given voltage reference value, and parameters k1 and k2 are the controller parameters to be adjusted.

[0076] Through the above design, the equivalent closed-loop transfer function of the system can be expressed as:

[0077]

[0078] Where y(s) is the Laplace transform of the system output, r(s) is the Laplace transform of the system input, s is the complex frequency domain variable, ω c is the natural oscillation angular frequency of the system.

[0079] By adjusting the controller bandwidth ω c The observer bandwidth and gain coefficient b0 can optimize the output characteristics of the system and improve the robustness and dynamic response of the system.

[0080] This invention proposes a side-by-side array of DD coils for transmission, rather than the traditional single-coil or orthogonal coupling approach. This design increases magnetic field coverage and enhances the wireless charging system's robustness, making it suitable for dynamic drifting of AUVs during docking at charging stations. The receiving end utilizes a dual orthogonal coil structure, capable of simultaneously picking up magnetic flux in both horizontal and vertical directions, improving magnetic coupling efficiency and reducing energy transmission losses due to positional variations.

[0081] Integrating the characteristics of wireless power transmission, this invention employs an LCC-S compensation topology. Compared to traditional SS compensation, this LCC-S compensation structure achieves constant current output at the transmitter, enhancing the system's voltage regulation and making it suitable for scenarios with dynamic load fluctuations. The input and output characteristics of the LCC-S compensation network are derived and optimized, and the impact of different parameters on system performance is analyzed. The effects of the compensation inductor and coil internal resistance on the system's output voltage and transmitter current are studied. The influence of the seawater medium system frequency on energy transmission is also investigated.

[0082] The technical solution of the present invention can be implemented through computer software, hardware, or a combination thereof. In hardware implementation, the LADRC-based voltage regulation control strategy can be implemented through electronic units such as application-specific integrated circuits (ASICs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), or microcontrollers (such as the STM32F103C8T6). For example, the system's high-frequency inverter circuit I adopts a full-bridge topology, with the IR2104 driver chip controlling the switching of the IAUC60N04S6L030H power MOSFETs. The resonant parameters of the LCC-S compensation network II are hardware-tuned using precision inductor and capacitor components. The arrayed DD coils and orthogonal receiving coils of the magnetic coupling device III are optimized through Litz wire winding and ferrite core integration. The linear active disturbance rejection control (LADRC) algorithm built into the controller V can achieve real-time disturbance estimation and duty cycle adjustment using an FPGA or ARM processor.

[0083] For software implementation, control logic can be implemented through modular programming. For example, the LADRC's disturbance observation and compensation module, the Buck circuit duty cycle calculation module, and the anti-drift optimization algorithm can be encapsulated as independent functional units. Finite element simulation of the magnetic coupling structure, LCC-S network parameter optimization, and seawater medium frequency response modeling can be performed using MATLAB / Simulink. Simulation results are embedded in the control flow to enhance the system's adaptability.

[0084] The system structure diagram in the attached figure ( Figure 1 ) and LADRC control block diagram ( Figure 7 ) reveals the interaction logic of the functional modules. Each box in the flowchart represents an independent module, such as the high-frequency inverter control module, the ESO disturbance estimation module, and the nonlinear error feedback module. Its code segment contains executable instructions to implement specific functions. It is important to note that the module execution order can be dynamically adjusted according to the operating conditions. For example, load detection and duty cycle adjustment can be processed in parallel to improve response speed.

[0085] The program code of the present invention can be executed by a microprocessor to achieve the following functions: real-time acquisition of voltage and current signals at the charging output end; calculation of the total system disturbance and generation of disturbance compensation based on the linear active disturbance rejection control (LADRC) algorithm; dynamic adjustment of the LCC-S compensation network parameters and the inverter duty cycle according to the compensation amount, and output of a high-frequency PWM drive signal; maintenance of efficient and stable energy transmission within a receiving coil offset range of ±120 mm; and, in addition, the program can be integrated into the underwater vehicle control system or used as an independent control module to communicate with the charging platform to achieve automated charging management.

[0086] The present invention also includes a method for controlling voltage stabilization of underwater magnetically coupled resonant wireless power transmission, which is implemented based on the above-mentioned underwater magnetically coupled resonant wireless power transmission voltage stabilization control system and includes the following steps:

[0087] S1. After the system is started, the array-type orthogonal magnetic coupling device generates complementary horizontal and vertical magnetic fields through the power supply, inverter circuit, and transmitter compensation network. The horizontal and vertical magnetic fields can cover the offset range of the underwater vehicle.

[0088] S2. The dual orthogonal coils pick up energy from the horizontal and vertical magnetic fields. They operate based on a compensation network at the receiving end. The energy from the horizontal and vertical magnetic fields is converted into direct current through a rectifier and filter module.

[0089] S3. The linear active disturbance rejection control module uses the extended state observer to estimate the total disturbance of the system in real time and perform feedforward compensation. On the other hand, it uses the linear feedback vacancy rate to adjust the duty cycle of the converter to achieve voltage regulation.

[0090] In summary, the embodiments of the present application provide an underwater wireless charging system and control method thereof. This system, through the collaborative design of hardware and software, integrates an anti-offset magnetic coupling structure, an LCC-S constant current compensation network, and linear active disturbance rejection control (LADRC) technology to achieve efficient voltage regulation and disturbance rejection of the charging output voltage in complex underwater environments. The hardware portion includes an on-demand expandable array of transmitting coils and receiving coils, an LCC-S compensation circuit, and a full-bridge inverter. The software portion utilizes the ESO to estimate the total system disturbance in real time and adjusts the inverter duty cycle through linear state feedback, thereby achieving both fast response and robustness.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater magnetically coupled resonant wireless power transmission voltage stabilization control system, characterized in that: include: A transmitter, comprising a power supply, an inverter circuit, a transmitter compensation network, and an array-type orthogonal magnetic coupling device, wherein the array-type orthogonal magnetic coupling device comprises four DD-type coils, which are alternately wound to generate horizontal and vertical magnetic fields; A receiving end, comprising a dual orthogonal coil, a receiving end compensation network, a rectifier filter module and a DC-DC converter, wherein the dual orthogonal coil receives energy from the horizontal magnetic field and the vertical magnetic field, and the DC-DC converter comprises a linear active disturbance rejection control module; The linear active disturbance rejection control module includes an extended state observer and a linear feedback control rate. The extended state observer is used to estimate the total disturbance of the system in real time and perform feedforward compensation. The linear feedback control rate achieves voltage stabilization by adjusting the duty cycle of the converter.

2. The underwater magnetic coupling resonant wireless power transmission voltage stabilization control system according to claim 1, characterized in that: The dual orthogonal coils are integrated with ferrite cores.

3. The underwater magnetic coupling resonant wireless power transmission voltage stabilization control system according to claim 1, characterized in that: The transmitter compensation network includes a transmitter compensation capacitor, a compensation blocking capacitor and an equivalent internal resistance of the transmitter coil, wherein the transmitter compensation capacitor is connected in parallel with the series-connected compensation blocking capacitor, the transmitter coil inductance and the equivalent internal resistance of the transmitter coil; The receiving end compensation network includes a transmitting end compensation capacitor and a receiving end coil equivalent internal resistance, and the transmitting end compensation capacitor, the receiving end coil inductance and the receiving end coil equivalent internal resistance are connected in series in sequence.

4. The underwater magnetically coupled resonant wireless power transmission voltage stabilization control system according to claim 1, characterized in that: The dual orthogonal coil includes two orthogonally arranged rectangular coils, which pick up magnetic flux components in parallel and perpendicular directions and ensure the independence of energy reception through a decoupling design.

5. The underwater magnetic coupling resonant wireless power transmission voltage stabilization control system according to claim 1, characterized in that: Among the four DD-type coils, adjacent coils are wound in opposite ways, and the four DD-type coils are connected in series.

6. The underwater magnetically coupled resonant wireless power transmission voltage stabilization control system according to claim 1, characterized in that: The extended state observer adopts a linear design, and the calculation formula of the gain parameter of the extended state observer is: β1=3ω0 β2=3ω0 2 β3=ω0 3 Where β1 is the first gain parameter, β2 is the second gain parameter, β3 is the third gain parameter, and ω0 is the bandwidth of the extended state observer.

7. A method for controlling voltage stabilization of underwater magnetically coupled resonant wireless power transmission, implemented based on the underwater magnetically coupled resonant wireless power transmission voltage stabilization control system according to claims 1-6, characterized in that: The following steps are involved: After the system is started, the array-type orthogonal magnetic coupling device generates complementary horizontal and vertical magnetic fields through the power supply, inverter circuit, and transmitter compensation network. The horizontal and vertical magnetic fields can cover the offset range of the underwater vehicle. The dual orthogonal coils pick up energy from the horizontal and vertical magnetic fields. The dual orthogonal coils operate based on a receiving-end compensation network. The energy from the horizontal and vertical magnetic fields is converted into direct current through a rectifier and filter module. The linear active disturbance rejection control module is used to estimate the total disturbance of the system in real time and perform feedforward compensation through an extended state observer, and on the other hand, to achieve voltage stabilization by adjusting the duty cycle of the converter through linear feedback vacancy rate.

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