Underwater radio energy and information synchronous transmission system and method based on frequency division duplexing

Abstract

The application discloses a kind of underwater radio energy and information synchronous transmission system and method based on frequency division duplex, it is related to underwater intelligent equipment technical field, solve the technical problem that wireless charging is difficult to meet the energy supply and information interaction demand simultaneously.The system includes transmitting end, receiving end;Transmitting end, receiving end carry out magnetic field coupling charging through seawater medium;When transmitting end, receiving end carry out magnetic field coupling charging, transmitting end loads target information needing transmission by controlling the frequency variation of inverter unit, receiving end loads target information needing transmission by controlling the frequency variation of rectifier unit;Transmitting end, receiving end are respectively provided with transmitting modem module, receiving modem module to modulate and demodulate target information, for bidirectional transmission, the modulation of target information adopts frequency shift keying modulation mode.The application fuses underwater wireless charging and duplex communication function based on single main power link.

Description

Technical Field

[0001] This invention relates to the field of underwater intelligent equipment technology, and in particular to an underwater wireless power and information synchronization transmission system and method based on frequency division duplex. Background Technology

[0002] With the rapid development of autonomous underwater vehicles, unmanned underwater vehicles, and other intelligent underwater equipment, their endurance and operational efficiency increasingly depend on safe and reliable energy replenishment and status information exchange. Traditional wired charging methods typically require mechanical connectors for power transmission, which has significant limitations. Underwater wireless power transfer technology, which uses contactless energy transfer methods, is gradually becoming an important development direction for underwater equipment charging.

[0003] Underwater equipment typically requires information exchange during charging, such as charging start / stop control, output voltage, current, temperature, operating mode, and fault protection information. In existing technologies, this information is generally transmitted via an additional wireless communication module or a separate signal link. However, due to the high conductivity of seawater, conventional electromagnetic communication signals attenuate rapidly, significantly limiting communication distance and stability. Furthermore, the additional communication modules, modulation / demodulation circuits, and auxiliary coupling channels further increase system size, cost, and control complexity, hindering the miniaturization, integration, and high reliability design of underwater equipment. Therefore, synchronous wireless power and information transmission technology has emerged, utilizing the main power transmission link to simultaneously carry electrical energy and information, eliminating the need for a separate communication link. This reduces system complexity and improves integration to some extent.

[0004] In the process of realizing this invention, the inventors discovered at least the following problems in the prior art: Wireless charging for underwater intelligent equipment cannot simultaneously achieve power transmission and full-duplex communication with minimal additional hardware, making it difficult to meet the needs of energy replenishment and information exchange. Summary of the Invention

[0005] The purpose of this invention is to provide an underwater wireless power and information synchronization transmission system and method based on frequency division duplex (FDM) to solve the technical problem in the prior art that wireless charging of underwater intelligent equipment cannot simultaneously achieve power transmission and full-duplex communication with minimal additional hardware, thus failing to meet the needs of energy replenishment and status information interaction. The various technical effects of the preferred solutions among the many technical solutions provided by this invention are detailed below.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an underwater wireless power and information synchronization transmission system based on frequency division duplex (FDM), comprising a transmitter and a receiver. The transmitter and receiver together form an LCC-LCC resonant compensation structure, which is magnetically coupled and charged through seawater. During magnetically coupled charging, the transmitter loads the target information to be transmitted by controlling the operating frequency of the inverter unit, and the receiver loads the target information to be transmitted by controlling the operating frequency of the rectifier unit. The transmitter and receiver are respectively equipped with a transmit modulation and demodulation module and a receive modulation and demodulation module to modulate and demodulate the target information for FDM communication between the transmitter and receiver. The modulation of the target information adopts frequency shift keying (FSK) modulation.

[0007] Preferably, the transmitter further includes an input power supply connected in sequence. V bus Inverter unit, transmitter resonant compensation network, transmitter coil L ga The system includes a transmitter controller, which is electrically connected to the inverter unit and the transmitter modulation / demodulation module. The inverter unit is a full-bridge inverter structure, including power switching transistors. S 1. Power switching transistor S 2. Power switching transistor S 3. Power switching transistor S 4. Used to input power V bus The DC voltage is converted into a high-frequency AC voltage; the transmitter resonant compensation network includes a resonant inductor. L f_ga ,capacitance C ga and filter capacitors C f_ga The resonant inductor L f_ga One end is connected to the inverter unit, and the other end is connected to the capacitor. C ga Filter capacitor C f_ga The first plate is connected, and the capacitor C ga Filter capacitor C f_ga The second electrode plates are all connected to the inverter unit and the transmitting coil. L ga connect.

[0008] Preferably, the receiving end further includes receiving coils connected in sequence. L vaThe system includes a receiver-end resonant compensation capacitor, n transformers, multiple rectifier units, a battery load, and a receiver-end controller. The receiver-end controller is electrically connected to the rectifier units and the receiver modulation / demodulation module, and is used to control the switching of the rectifier units between rectification mode and bypass mode. The receiver-end resonant compensation capacitor includes capacitors connected in parallel. C va ,capacitance C f_va , and receiving coil L va A receiving end resonant compensation network is formed; the rectifier unit includes one active rectifier module and n-1 AC / DC rectifier modules.

[0009] A frequency division duplex-based underwater wireless power and information synchronization transmission method, operating through the aforementioned frequency division duplex-based underwater wireless power and information synchronization transmission system, includes the following steps: S100: Initialize the operating parameters, communication parameters, and reference control quantities of the transmitter controller and receiver controller to obtain transmitter initialization information and receiver initialization information. Set all rectifier units at the receiver to bypass state and send the receiver initialization information to the receiver via the main power link. The receiver receives and demodulates the receiver initialization information; S200: If the system meets the start-up power transmission conditions, the transmitter controller controls the inverter unit to convert the input DC power into high-frequency AC power, which is then transmitted through the transmitter resonant compensation network and the transmitter coil. L ga Coupled to the receiving end, power transmission is initiated; S300: The receiving end controller controls the number of rectifier units connected and samples the output current in real time. I bat and output voltage V bat The charging mode is determined based on charging demand and sampling results, and the output current is based on the charging mode. I bat Reference current, output voltage V bat S400: If the system has information transmission requirements, the transmitter and receiver use frequency shift keying modulation to transmit information bidirectionally through the main power link; S500: If the system receives a shutdown command, the output reaches the charging termination condition, the system detects a fault, or the transmitter and receiver lose effective coupling, the power transmission stops and the process ends.

[0010] Preferably, in step S200, the system meets the conditions for starting power transmission, including: the receiver receiving a valid start command, the system operating normally, the coupling state between the transmitter and receiver meeting the charging requirements, and the receiver being connected to a load.

[0011] Preferably, in step S300, the charging mode is determined based on the charging demand and sampling results as follows: when the output current is the main control target, it is determined to be constant current mode; when the output voltage is the main control target, it is determined to be constant voltage mode, so as to adapt to the charging strategy of constant current charging in the early stage and constant voltage charging in the later stage of the battery load.

[0012] Preferably, in step S300, in constant current mode, if the output current... I bat If the current is less than the reference current, increase the duty cycle; if the output current is less than the reference current, increase the duty cycle. I bat If the current exceeds the reference current, the duty cycle is reduced; in constant voltage mode, if the output voltage... V bat If the output voltage is less than the reference voltage, increase the duty cycle; if the output voltage... V bat If the voltage is greater than the reference voltage, the duty cycle is reduced; the expression for the duty cycle is: D = T 2 / ( T 1+ T 2), where, T 1 indicates the bypass time of the rectifier unit. T 2 indicates the rectification time of the rectifier unit.

[0013] Preferably, in step S400, the information in the information transmission requirement includes at least one of the following: output voltage, output current, charging mode, system status, fault information, and control command.

[0014] Preferably, in step S400, the transmitter controller loads target information by controlling the change in the operating frequency of the inverter unit, wherein the operating frequency of the inverter unit is within... f 1-Δ f A value of 1 indicates the transmission of binary 1, and the operating frequency is... f 1+Δ f A value of 1 indicates the transmission of binary 0, and the operating frequency is the base frequency at the transmitter. f 1 indicates no message is sent, Δ f 1 indicates the transmitter frequency offset; the receiver controller loads target information by controlling the operating frequency of the rectifier unit, and the rectifier unit's operating frequency is within... f 2-Δ f 2 indicates sending binary 1, and the operating frequency is... f 2+Δ f A value of 2 indicates the transmission of binary 0, operating at the receiver's fundamental frequency. f 2 indicates no information is being sent, Δ f 2 indicates the receiver frequency offset; the transmitter fundamental frequency. f 1 is 85kHz, the fundamental frequency of the receiver. f2 is 10kHz, and the frequency offset at the transmitting end is Δ. f 1. Receiver frequency offset Δ f Both are 1kHz.

[0015] Preferably, in step S400, during bidirectional information transmission, the process of demodulating the information at the transmitting end and the receiving end is as follows: the transmitting end samples the current envelope signal input to the main power link, and sequentially performs signal amplification, low-pass filtering, reference comparison, and frequency identification to demodulate the target information sent by the receiving end; the process of demodulating the information at the receiving end and the transmitting end is as follows: the receiving end samples the resonant current or rectifier side current signal, and sequentially performs filtering, comparison, and frequency identification to demodulate the target information sent by the transmitting end.

[0016] Implementing one of the above-described technical solutions of the present invention has the following advantages or beneficial effects: This invention utilizes a single main power magnetic coupling link for synchronous power and information transmission, integrating underwater wireless charging with full-duplex communication. This eliminates the need for separate communication links and additional modules, structurally reducing system complexity and size costs, and solving the problems of underwater communication signal attenuation and hardware integration difficulties. Information transmission via the main power link is unaffected by the high conductivity of seawater, improving the distance and stability of underwater information transmission. Simultaneously, full-duplex communication is achieved, meeting the requirements for status exchange and command interaction between the transmitter and receiver in underwater charging systems. By coordinating the operating frequency and status of the inverter unit at the transmitter and the rectifier unit at the receiver, efficient power transmission is ensured while simultaneous full-duplex communication is achieved without interrupting the power transmission process, improving the efficiency of energy replenishment and status monitoring for underwater equipment. Furthermore, information modulation and power regulation share a control unit, eliminating the need for additional control links and further enhancing system integration, meeting the energy replenishment and status information interaction needs of autonomous underwater vehicles, unmanned underwater vehicles, and other underwater intelligent equipment. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a circuit diagram of an underwater wireless power and information synchronization transmission system based on frequency division duplex, according to Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of power transmission in an underwater wireless power and information synchronization transmission system based on frequency division duplex, according to Embodiment 1 of the present invention. Figure 3This is a flowchart of the underwater wireless power and information synchronization transmission method based on frequency division duplex according to Embodiment 2 of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, various exemplary embodiments described below will be referenced to the accompanying drawings, which form part of the exemplary embodiments, illustrating various exemplary embodiments that may be used to implement the present invention. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, and apparatuses consistent with some aspects of the present invention disclosed as detailed in the appended claims, and other embodiments may be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and spirit of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the referred element must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. The term "multiple" means two or more. The terms "connected" and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, communication connections, direct connections, indirect connections through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more of the related listed items. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] To illustrate the technical solution described in this invention, specific embodiments are described below, showing only the parts related to the embodiments of this invention.

[0021] Example 1: like Figure 1 , Figure 2As shown, this invention provides an underwater wireless power and information synchronization transmission system based on frequency division duplex (FDM), including a transmitter and a receiver. The transmitter and receiver together form an LCC-LCC resonant compensation structure, which performs magnetic field coupling charging through seawater. The LCC-LCC resonant compensation structure, by adding a small number of inductors and capacitors, adapts to the high-power, wide-range adjustable underwater application requirements, achieving extremely high safety, stable output characteristics, and strong anti-offset capability. It is a topology suitable for high-power underwater wireless charging. The LCC-LCC resonant compensation structure can be replaced by SS (series-series), SP (series-parallel), PS (parallel-series), PP (parallel-parallel), and other resonant compensation structures. These structures simplify circuit design, reduce the use of resonant devices, and lower system hardware costs, making them suitable for low-to-medium power underwater wireless charging scenarios. During magnetic field coupling charging at the transmitter and receiver, the transmitter loads the target information to be transmitted by controlling the operating frequency of the inverter unit (DC to AC), and the receiver loads the target information to be transmitted by controlling the operating frequency of the rectifier unit (AC to DC). The inverter and rectifier units form the main power circuit for wireless charging. Their operating frequency is easily controlled, allowing information loading through slight frequency adjustments. The transmitter and receiver are equipped with transmit and receive modulation / demodulation modules respectively for modulating and demodulating the target information. Both the transmitter and receiver can perform information modulation and demodulation, enabling frequency-division duplex communication between them. Target information modulation employs frequency-shift keying (FSK) modulation. FSK transmits digital information by changing the frequency of the carrier signal while maintaining constant amplitude and phase, resulting in strong noise immunity, simple implementation, and higher accuracy and stability. It is particularly suitable for low-speed data transmission in noisy environments like underwater. FSK can be replaced with amplitude-shift keying (APS) modulation, where information loading is achieved by adjusting the output amplitude of the rectifier / inverter unit. This method offers simpler modulation / demodulation circuitry and lower implementation costs. In this embodiment, an architecture for synchronous transmission of power and information based on a single main power magnetic coupling link integrates underwater wireless charging and full-duplex communication functions. This eliminates the need for additional communication links and modules, structurally reducing system complexity and volume costs. It also solves the problems of underwater communication signal attenuation and the difficulty of hardware integration. Information transmission is achieved through the main power link, which is not significantly affected by the high conductivity of seawater, thus improving the distance and stability of underwater information transmission. At the same time, full-duplex communication is achieved, meeting the requirements for status exchange and command interaction between the transmitter and receiver in the underwater charging system.By coordinating the operating frequency and status of the inverter unit at the transmitting end and the rectifier unit at the receiving end, full-duplex communication can be completed simultaneously while ensuring efficient power transmission without interrupting the power transmission process, thus improving the efficiency of energy replenishment and status monitoring for underwater equipment. Furthermore, the information modulation and power regulation share the same control unit, eliminating the need for additional control links and further enhancing the system's integration, meeting the energy replenishment and status information exchange needs of underwater intelligent equipment such as autonomous underwater vehicles and unmanned underwater vehicles.

[0022] As an optional implementation method, such as Figure 1 As shown, the transmitter also includes an input power supply connected in sequence. V bus Inverter unit, transmitter resonant compensation network, transmitter coil L ga The transmitter controller is electrically connected to the inverter unit and the transmission modem module, respectively, facilitating its control over the charging and information transmission processes. Input power. V bus It is a DC power supply, and the inverter unit is a full-bridge inverter structure, including power switching transistors. S 1. Power switching transistor S 2. Power switching transistor S 3. Power switching transistor S 4. Used to input power V bus The DC voltage is converted into a high-frequency AC voltage; the transmitter resonant compensation network includes a resonant inductor. L f_ga ,capacitance C ga and filter capacitors C f_ga Transmitter resonant compensation network and transmitting coil L ga To enhance power transmission capability, resonant inductors L f_ga One end is connected to the inverter unit, and the other end is connected to the capacitor. C ga Filter capacitor C f_ga The first plate is connected to the capacitor. C ga Filter capacitor C f_ga The second electrode plates are connected to the inverter unit and the transmitting coil. L ga connect.

[0023] As an optional implementation method, such as Figure 1 As shown, the receiving end also includes receiving coils connected in sequence. Lva The system consists of a receiver-side resonant compensation capacitor, n transformers, multiple rectifier units, a battery load, and a receiver-side controller. The receiver-side controller is electrically connected to both the rectifier units and the receiver modem module, and is used to control the switching of the rectifier units between rectification mode and bypass mode. The n transformers are connected in parallel to facilitate adaptation to different voltage / current levels, and their leakage inductance can participate in resonance, reducing the need for additional resonant components. The receiver-side resonant compensation capacitor includes capacitors connected in parallel. C va ,capacitance C f_va , and receiving coil L va A receiving end resonant compensation network is formed, and the capacitor... C va With receiving coil L va Series connection; the rectifier unit includes one active rectifier module (including switching transistors). Q 11 Switching transistor Q 21 and diodes D 1. Diode D 2) and n-1 AC / DC rectifier modules.

[0024] The embodiment is merely a specific example and does not indicate that this is the only way to implement the present invention.

[0025] Example 2: A method for underwater wireless power and information synchronization transmission based on frequency division duplex, such as... Figure 3 As shown, the operation of the frequency division duplex-based underwater wireless power and information synchronization transmission system according to Embodiment 1 includes the following steps: S100: Initialize the operating parameters, communication parameters, and reference control quantities of the transmitter controller and receiver controller to obtain transmitter initialization information and receiver initialization information. Set all rectifier units of the receiver to bypass state to avoid uncontrolled power output, and send the receiver initialization information to the receiver via the main power link. The receiver receives and demodulates the receiver initialization information; S200: If the system meets the start-up power transmission conditions, the transmitter controller controls the inverter unit to convert the input DC power into high-frequency AC power, which is then transmitted through the transmitter resonant compensation network and the transmitter coil. L ga Coupled to the receiving end, power transmission is initiated; S300: The receiving end controller controls the number of rectifier units connected and samples the output current in real time. I bat and output voltage V bat The charging mode is determined based on charging demand and sampling results, and the output current is based on the charging mode. Ibat Reference current, output voltage V bat The reference voltage is adjusted to regulate the duty cycle of the rectifier unit; S400: If the system requires information transmission, the transmitter and receiver transmit information bidirectionally via the main power link using frequency shift keying modulation; S500: If the system receives a shutdown command, the output reaches the charging termination condition, the system detects a fault, or the transmitter and receiver lose effective coupling, the power transmission stops and the process ends. This embodiment constructs a closed-loop collaborative control process for power transmission and information interaction, integrating system startup, mode determination, power adjustment, information transmission, and shutdown determination into a unified closed-loop logic. It has self-adjusting capabilities for fault determination and start / stop control, improving the system's reliability and practicality. While continuously transmitting power, it can simultaneously complete full-duplex communication without interrupting the charging process, improving the overall efficiency of underwater equipment energy replenishment and status monitoring. It can be directly applied to autonomous underwater vehicles, unmanned underwater vehicles, and other underwater intelligent equipment.

[0026] As an optional implementation, in step S200, the system meets the conditions for starting power transmission, including: the receiving end receives a valid start command, the system is in normal working condition, the coupling state between the transmitting end and the receiving end meets the charging requirements, and the receiving end is connected to a load.

[0027] As an optional implementation, in step S300, determining the charging mode based on charging demand and sampling results specifically involves: when the output current is the primary control target, determining it as constant current mode; and when the output voltage is the primary control target, determining it as constant voltage mode. This adapts to the charging strategy of constant current charging in the early stage and constant voltage charging in the later stage for the battery load, thereby ensuring both charging speed and battery safety and lifespan. In constant current mode, if the output current... I bat If the current is less than the reference current, increase the duty cycle; if the output current is less than the reference current, increase the duty cycle. I bat If the current exceeds the reference current, the duty cycle is reduced; in constant voltage mode, if the output voltage... V bat If the output voltage is less than the reference voltage, increase the duty cycle; if the output voltage... V bat If the voltage is greater than the reference voltage, the duty cycle is reduced; the expression for the duty cycle is: D = T 2 / ( T 1+ T 2), where, T 1 indicates the bypass time of the rectifier unit. T2 indicates the rectification time of the rectifier unit. Using the duty cycle as the core control parameter, it achieves precise closed-loop control of constant current / constant voltage charging, and also completes information loading in conjunction with frequency switching, realizing multi-parameter control and improving the integration and flexibility of system control. System output power. P o = V bat • I bat Total output current I bat =∑ I bati ( I bati (where i is the output current of the i-th rectifier branch) can achieve discrete power adjustment by controlling the number of rectifier modules in operation, and continuous fine adjustment of power by adjusting the duty cycle, ultimately achieving precise adjustment of the system output power, meeting the power adjustment needs of underwater equipment at different charging stages, and taking into account both adjustment range and adjustment accuracy.

[0028] As an optional implementation, in step S400, the information in the information transmission requirement includes at least one of the following: output voltage, output current, charging mode, system status, fault information, and control command.

[0029] As an optional implementation, in step S400, the transmitter controller loads target information by controlling the operating frequency of the inverter unit. Specifically, the transmitter controller loads target information by controlling the inverter unit to switch its operating state according to a preset frequency. The operating frequency of the inverter unit is... f 1-Δ f A value of 1 indicates the transmission of binary 1, and the operating frequency is... f 1+Δ f A value of 1 indicates the transmission of binary 0, and the operating frequency is the base frequency at the transmitter. f 1 indicates no message is sent, Δ f 1 indicates the transmitter frequency offset; the receiver controller loads target information by controlling the operating frequency of the rectifier unit. Specifically, it controls the rectifier unit to switch between bypass / rectification modes at a preset frequency, causing a change in the main power link input current envelope to load information. The rectifier unit's operating frequency is within... f 2-Δ f 2 indicates sending binary 1, and the operating frequency is... f 2+Δ f A value of 2 indicates the transmission of binary 0, operating at the receiver's fundamental frequency. f 2 indicates no information is being sent, Δ f 2 indicates the receiver frequency offset. In this embodiment, the transmitter's fundamental frequency... f 1 is 85kHz, the fundamental frequency of the receiver.f 2 is 10kHz, and the frequency offset at the transmitting end is Δ. f 1. Receiver frequency offset Δ f Both are 1kHz, meaning the transmitting end operates at 84-86kHz and the receiving end operates at 9-11kHz. These parameters balance power transmission efficiency and information transmission stability, representing the optimal parameter selection for underwater scenarios. This embodiment sets differentiated frequency shift keying parameters for the transmitting end inverter unit and the receiving end rectifier unit (85kHz±1kHz for the transmitting end and 10kHz±1kHz for the receiving end), achieving full-duplex communication based on the main power link and overcoming the unidirectional transmission deficiency of existing synchronous transmission schemes. Frequency parameters (such as the transmitting end's base frequency) can also be adjusted according to the actual application scenario. f 1 = 100kHz, the fundamental frequency of the receiver. f 2 = 15kHz, transmitter frequency offset Δ f 1. Receiver frequency offset Δ f (2 are both 2kHz); higher frequencies can increase information transmission speed, and larger offsets can simplify demodulation; however, excessively high frequencies are easily affected by seawater, increasing energy loss, and excessively large offsets can cause the operating frequency to deviate from the resonant frequency, resulting in unstable system power transmission.

[0030] As an optional implementation, in step S400, during bidirectional information transmission, both the transmitting and receiving ends need to demodulate the information to restore it. The process of the transmitting end demodulating the information of the receiving end is as follows: the transmitting end samples the current envelope signal input to the main power link, and sequentially performs signal amplification, low-pass filtering, reference comparison, and frequency identification to demodulate the target information transmitted by the receiving end; the process of the receiving end demodulating the information of the transmitting end is as follows: the receiving end samples the resonant current or the current signal of the rectifier unit, and sequentially performs filtering, comparison, and frequency identification to demodulate the target information transmitted by the transmitting end.

[0031] The above description is merely a preferred embodiment of the present invention. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A frequency division duplex-based underwater wireless power and information synchronization transmission system, characterized in that, It includes a transmitter and a receiver; the transmitter and receiver together form an LCC-LCC resonant compensation structure, which is charged by magnetic field coupling through seawater medium; When the transmitting end and the receiving end are performing magnetic field coupling charging, the transmitting end loads the target information to be transmitted by controlling the change of the operating frequency of the inverter unit, and the receiving end loads the target information to be transmitted by controlling the change of the operating frequency of the rectifier unit. The transmitting end and the receiving end are respectively equipped with a transmitting modulation and demodulation module and a receiving modulation and demodulation module to modulate and demodulate the target information, which is used for frequency division duplex communication between the transmitting end and the receiving end. The modulation of the target information adopts frequency shift keying modulation. The inverter unit operates at a frequency of f 1-Δ f A value of 1 indicates the transmission of binary 1, and the operating frequency is... f 1+Δ f A value of 1 indicates the transmission of binary 0, and the operating frequency is the base frequency at the transmitter. f A value of 1 indicates no message is being sent. Δ f 1 indicates the transmitter frequency offset; the rectifier unit operates at a frequency of... f 2-Δ f 2 indicates sending binary 1, and the operating frequency is... f 2+Δ f A value of 2 indicates the transmission of binary 0, operating at the receiver's fundamental frequency. f 2 indicates no information is being sent, Δ f 2 indicates the receiver frequency offset; the transmitter fundamental frequency. f 1 is 85kHz, the fundamental frequency of the receiver. f 2 is 10kHz, and the frequency offset at the transmitting end is Δ. f 1. Receiver frequency offset Δ f Both are 1kHz; The receiving end also includes receiving coils L connected in sequence. va The system includes a receiver-end resonant compensation capacitor, n transformers, multiple rectifier units, a battery load, and a receiver-end controller. The receiver-end controller is electrically connected to the rectifier units and the receiver modulation / demodulation module, and is used to control the switching of the rectifier units between rectification mode and bypass mode. The receiver-end resonant compensation capacitor includes capacitors C connected in parallel. va Capacitor C f_va , with receiving coil L va A receiving end resonant compensation network is formed; the rectifier unit includes one active rectifier module and n-1 AC / DC rectifier modules.

2. The underwater wireless power and information synchronization transmission system based on frequency division duplex as described in claim 1, characterized in that, The transmitter also includes sequentially connected input power supplies. V bus Inverter unit, transmitter resonant compensation network, transmitter coil L ga The system includes a transmitter controller, which is electrically connected to the inverter unit and the transmitter modulation / demodulation module. The inverter unit is a full-bridge inverter structure, including power switching transistors. S 1. Power switching transistor S 2. Power switching transistor S 3. Power switching transistor S 4. Used to input power V bus The DC voltage is converted into a high-frequency AC voltage; the transmitter resonant compensation network includes a resonant inductor. L f_ga ,capacitance C ga and filter capacitors C f_ga The resonant inductor L f_ga One end is connected to the inverter unit, and the other end is connected to the capacitor. C ga Filter capacitor C f_ga The first plate is connected, and the capacitor C ga Filter capacitor C f_ga The second electrode plates are all connected to the inverter unit and the transmitting coil. L ga connect.

3. A method for underwater wireless power and information synchronization transmission based on frequency division duplex, characterized in that, The operation of the underwater wireless power and information synchronization transmission system based on frequency division duplex as described in claim 1 includes the following steps: S100: Initializes the operating parameters, communication parameters, and reference control quantities of the transmitter controller and receiver controller, obtains transmitter initialization information and receiver initialization information, sets all rectifier units of the receiver to bypass state, and sends the receiver initialization information to the receiver via the main power link. The receiver receives and demodulates the receiver initialization information. S200: If the system meets the startup power transmission conditions, the transmitter controller controls the inverter unit to convert the input DC power into high-frequency AC power, which is then transmitted through the transmitter resonant compensation network and the transmitter coil. L ga Coupled to the receiver, power transmission is initiated; S300: The receiver controller controls the number of rectifier units connected and samples the output current in real time. I bat and output voltage V bat The charging mode is determined based on charging demand and sampling results, and the output current is based on the charging mode. I bat Reference current, output voltage V bat The reference voltage regulation has been connected to the duty cycle of the rectifier unit; S400: If the system requires information transmission, the transmitter and receiver transmit information bidirectionally through the main power link using frequency shift keying modulation. S500: If the system receives a shutdown command, the output reaches the charging termination condition, the system detects a fault, or the transmitter and receiver lose effective coupling, power transmission will stop and the process will end.

4. The underwater wireless power and information synchronization transmission method based on frequency division duplex according to claim 3, characterized in that, In step S200, the system meets the conditions for power transmission to start, including: the receiver receiving a valid start command, the system operating normally, the coupling state between the transmitter and receiver meeting the charging requirements, and the receiver being connected to a load.

5. The underwater wireless power and information synchronization transmission method based on frequency division duplex according to claim 3, characterized in that, In step S300, the charging mode is determined based on the charging demand and sampling results as follows: when the output current is the main control target, it is determined to be constant current mode; when the output voltage is the main control target, it is determined to be constant voltage mode, in order to adapt to the charging strategy of constant current charging in the early stage and constant voltage charging in the later stage of the battery load.

6. The underwater wireless power and information synchronization transmission method based on frequency division duplex according to claim 5, characterized in that, In step S300, in constant current mode, if the output current... I bat If the current is less than the reference current, increase the duty cycle; if the output current is less than the reference current, increase the duty cycle. I bat If the current exceeds the reference current, the duty cycle is reduced; in constant voltage mode, if the output voltage... V bat If the output voltage is less than the reference voltage, increase the duty cycle; if the output voltage... V bat If the voltage is greater than the reference voltage, the duty cycle is reduced; the expression for the duty cycle is: D = T 2 / ( T 1+ T 2), where, T 1 indicates the bypass time of the rectifier unit. T 2 indicates the rectification time of the rectifier unit.

7. The underwater wireless power and information synchronization transmission method based on frequency division duplex according to claim 3, characterized in that, In step S400, the information in the information transmission requirement includes at least one of the following: output voltage, output current, charging mode, system status, fault information, and control commands.

8. The underwater wireless power and information synchronization transmission method based on frequency division duplex according to claim 3, characterized in that, In step S400, during bidirectional information transmission, the process of demodulating the information from the transmitter to the receiver is as follows: the transmitter samples the current envelope signal input to the main power link, and sequentially performs signal amplification, low-pass filtering, reference comparison, and frequency identification to demodulate the target information sent by the receiver; the process of demodulating the information from the receiver to the transmitter is as follows: the receiver samples the resonant current or rectifier-side current signal, and sequentially performs filtering, comparison, and frequency identification to demodulate the target information sent by the transmitter.

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