Unmanned ship anti-offset wireless power transmission system based on reconfigurable trapezoidal magnetic coupling mechanism

Abstract

The invention discloses an unmanned ship anti-offset wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism, and the system comprises an MCR-WPT topological structure based on an LCC-S compensation network, and the topological structure comprises an inverter circuit, the LCC-S compensation network based on a reconfigurable coil, a rectification circuit, and a DC-DC converter. The input end of the inverter circuit is connected with a power supply and is used for converting the power supply into a high-frequency alternating-current power supply; the LCC-S compensation network based on the reconfigurable coil comprises a primary side and a secondary side, the input end of the primary side is connected with the output end of the inverter circuit, an anti-offset magnetic coupling mechanism is connected between the primary side and the secondary side, and the output end of the secondary side is connected with the rectifying circuit; the rectifying circuit is used for converting the high-frequency alternating current into direct current; and the DC-DC converter is used for completing the conversion of the voltage level of the output end. According to the invention, the magnetic coupling mechanism can be flexibly adjusted for unmanned ships with different voltage levels so as to realize efficient charging, and the offset resistance of the system is enhanced.

Description

A drift-resistant wireless power transfer system for unmanned surface vessels based on a reconfigurable trapezoidal magnetic coupling mechanism Technical Field

[0001] This invention relates to the field of unmanned surface vessel (USV) wireless power transmission technology, and more specifically to an unmanned surface vessel anti-drift wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism. Background Technology

[0002] Wireless Power Transfer (WPT) eliminates the limitations on equipment flexibility and safety hazards caused by traditional wired power supply methods, improving the safety and portability of power use. It is now widely used in industrial equipment, rail transportation, electric vehicles, consumer electronics, biomedical implants, and underwater power supply. Applying WPT to unmanned vessels enables on-the-go charging, effectively improving shore power utilization and charging efficiency. Furthermore, WPT eliminates the need for charging cables to shore power, thereby improving operational safety, reducing system maintenance complexity, and lowering charging labor costs.

[0003] However, current unmanned surface vessels (USVs) typically rely on wired shore power charging, which suffers from issues such as aging charging interfaces, short circuits due to humid environments, complex wiring, and electrical sparks, increasing the risk of charging safety accidents. Furthermore, wired charging requires manual insertion and removal of the charging interface and necessitates parking the USV in a designated location, increasing system maintenance complexity, raising labor costs, and limiting the USV's mooring locations. Simultaneously, compared to wireless charging for new energy vehicles, USVs are more susceptible to displacement due to wind and waves during wireless charging, causing dynamic changes in the relative distance, angle, and area between the ship-side and shore-side coils. This leads to variations in the coil coupling coefficient and affects the system's transmission efficiency and power.

[0004] Therefore, there is an urgent need for a marine wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism, which can have good anti-deviation, fault tolerance and dynamic tracking capabilities to meet the high-efficiency charging requirements of unmanned ships. Summary of the Invention

[0005] In view of this, the present invention provides an unmanned vessel anti-drift wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism to solve the technical problem in the prior art that unmanned vessels are easily deviated by factors such as wind and waves when wirelessly charging, resulting in low system output power and magnetic leakage.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an unmanned surface vessel anti-drift wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism, comprising: an MCR-WPT topology based on an LCC-S compensation network; the MCR-WPT topology based on the LCC-S compensation network includes an inverter circuit, an LCC-S compensation network based on reconfigurable coils, a rectifier circuit, and a DC-DC converter; the input terminal of the inverter circuit is connected to a power supply for converting the power supply into high-frequency AC power; the LCC-S compensation network based on reconfigurable coils includes... The system consists of a primary and a secondary side. The input of the primary side is connected to the output of the inverter circuit. An anti-offset magnetic coupling mechanism connects the primary and secondary sides. The output of the secondary side is connected to the rectifier circuit, which is used to dynamically switch the number of coils and optimize system compensation parameters to compensate for mutual inductance changes and impedance mismatch caused by offset, so as to maintain constant voltage output and efficient and stable transmission of the system. The rectifier circuit is used to convert high-frequency AC power to DC power, and adopts one of the following: synchronous rectifier circuit, full-wave rectifier circuit, or bridge rectifier circuit. The DC-DC converter is used to complete the conversion of the output voltage level to meet the battery voltage level requirements and charge the unmanned surface vessel battery.

[0007] Furthermore, the primary side of the LCC-S compensation network based on reconfigurable coil includes a resonant inductor connected in series with a resonant capacitor. The input terminal of the primary side is connected to the output terminal of the inverter circuit to achieve constant current output on the primary side. The secondary side of the LCC-S compensation network includes a series capacitor and the coil self-inductance. The output terminal is connected to the input terminal of the rectifier circuit, and the output terminal of the rectifier circuit is connected to the DC-DC converter to achieve constant voltage output on the secondary side.

[0008] Furthermore, both the primary and secondary coils are wound using coils of the same size; when the system is in a resonant state, the equivalent self-inductance L of the primary side based on the LCC-S compensation network of the reconfigurable coil is... px With compensation capacitor C pi Satisfying the relation: Among them, L f C f These are the primary resonant inductor and capacitor, respectively, C pi L px and C si L sx (x=1, 2, 3) are the primary and secondary side compensation capacitors and equivalent self-inductance, respectively.

[0009] Furthermore, the primary and secondary sides of the LCC-S compensation network based on reconfigurable coils both employ three sets of reconfigurable rounded trapezoidal coils. The number of coils connected to the system is dynamically adjusted by a switching switch to compensate for changes in mutual inductance caused by offset.

[0010] Furthermore, the method for determining the optimization parameters of the rounded trapezoidal coil includes: modeling the magnetic field distribution of a single-turn trapezoidal coil based on the Biot-Savart law, optimizing the inner diameter, tilt angle, turn spacing, rounded radius, and number of turns; verifying the influence of different parameter magnetic coupling coil models on self-inductance, mutual inductance, and coupling coefficient through simulation, and determining the optimal magnetic coupling coil parameters.

[0011] Furthermore, the rounded trapezoidal magnetic coupling mechanism has a hybrid electromagnetic shielding layer; the hybrid electromagnetic shielding layer includes a ferrite layer and a nanocrystalline layer that are closely attached to the surface of the coil, and the two are placed alternately, with an aluminum plate layer on the outside of the ferrite layer and the nanocrystalline layer, and a nanocrystalline layer embedded in the center of the aluminum plate layer.

[0012] Furthermore, the inverter circuit includes: an H-bridge topology consisting of four semiconductor devices with switching characteristics; a left half-bridge formed by connecting devices S1 and S2 in series, and a right half-bridge formed by connecting devices S3 and S4 in series. Both ends of the left and right half-bridges are connected to the positive and negative terminals of the power supply. The midpoints of the left and right half-bridges serve as the AC output terminals of the inverter circuit, used to convert the power supply into high-frequency AC power.

[0013] Furthermore, the rectifier circuit adopts a full-bridge and half-bridge rectifier topology structure composed of semiconductor switching devices with switching characteristics.

[0014] Secondly, the present invention also provides a method for offset-resistant wireless power transmission of unmanned vessels based on a reconfigurable trapezoidal magnetic coupling mechanism, applied to the unmanned vessel offset-resistant wireless power transmission system based on the reconfigurable trapezoidal magnetic coupling mechanism described in the above technical solution, comprising: converting DC power into high-frequency AC power through an inverter circuit; dynamically adjusting the coil combination using the reconfigurable magnetic coupling mechanism to compensate for voltage fluctuations caused by mutual inductance changes due to offset; and completing voltage level conversion and outputting DC power to the unmanned vessel battery through a rectifier circuit and a DC-DC converter.

[0015] Furthermore, the reconfigurable magnetic coupling mechanism is used to dynamically adjust the coil combination to compensate for the change in mutual inductance caused by the offset. This includes: when the hull is offset, determining whether the voltage level and output power meet the usage requirements. If they do, the phase shift angle of the inverter circuit is reduced to increase the output voltage. If reducing the phase shift angle of the inverter circuit cannot meet the voltage level or output power requirements when the hull is offset, the voltage and power compensation of the system is completed by adjusting the number of magnetic coupling coils.

[0016] Compared to existing technologies, the unmanned surface vessel (USV) anti-offset wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism proposed in this invention has the following advantages: By using an inverter circuit to convert power into high-frequency AC, the efficiency of wireless power transfer can be effectively improved, resulting in higher system integration and flexibility. Using an LCC-S compensation network based on reconfigurable coils, the number of coils and system compensation parameters can be dynamically switched, enabling the system to cope with different working environments and load changes, automatically adjusting mutual inductance changes during power transfer to maintain a stable output voltage. The anti-offset magnetic coupling mechanism between the primary and secondary sides can effectively compensate for magnetic coupling offset caused by coil position changes or external interference, allowing the system to maintain a high-efficiency and reliable operating state in different application environments. This invention can effectively compensate for mutual inductance changes caused by magnetic field offset, ensuring that the system can maintain a stable constant voltage output under different environmental conditions, providing efficient and reliable power transfer for USVs and guaranteeing efficiency and stability during battery charging. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the unmanned vessel anti-offset wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism provided by the present invention; Figure 2 is a circuit diagram of the MCR-WPT topology based on an LCC-S compensation network provided by the present invention; Figure 3 is a schematic diagram of the MCR-WPT network based on a reconfigurable coil provided by the present invention; Figure 4 is a flowchart of the working mode switching provided by the present invention; Figure 5 is a schematic diagram of the single-turn trapezoidal coil analysis model provided by the present invention; Figure 6 is an analytical curve of the relationship between magnetic induction intensity and tilt angle θ and coil inner diameter n0 provided by the present invention; Figure 7 is a schematic diagram of the equivalent model of magnetic coupling mechanism parameters and magnetic field distribution provided by the present invention; Figure 8 is a schematic diagram of the magnetic coupling mechanism parameter optimization process provided by the present invention; Figure 9 is a schematic diagram of the hybrid electromagnetic shielding layer provided by the present invention; Figure 10 is a schematic diagram of the system workflow provided by the present invention. Detailed Implementation

[0018] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0019] Example 1 (Referring to Figure 1) provides an unmanned surface vessel (USV) offset-resistant wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism, comprising: an MCR-WPT topology based on an LCC-S compensation network; the MCR-WPT topology includes an inverter circuit, an LCC-S compensation network based on reconfigurable coils, a rectifier circuit, and a DC-DC converter; the input terminal of the inverter circuit is connected to a power supply for converting the power supply into high-frequency AC power; the LCC-S compensation network based on reconfigurable coils includes... The system consists of a primary and a secondary side. The input terminal of the primary side is connected to the output terminal of the inverter circuit. An anti-offset magnetic coupling mechanism connects the primary and secondary sides. The output terminal of the secondary side is connected to the rectifier circuit, which is used to dynamically switch the number of coils and optimize system compensation parameters to compensate for mutual inductance changes and impedance mismatch caused by offset. The rectifier circuit is used to convert high-frequency AC power to DC power, and adopts one of the following: synchronous rectifier circuit, full-wave rectifier circuit, or bridge rectifier circuit. The DC-DC converter is used to complete the output voltage level conversion to meet the battery voltage level requirements and charge the unmanned surface vessel's battery.

[0020] The unmanned surface vessel (USV) anti-offset wireless power transfer system provided in this embodiment, through the combination of inverter and rectifier circuits, can convert high-frequency AC power into DC power to meet the charging requirements of USV batteries. Combined with the LCC-S compensation network and anti-offset magnetic coupling mechanism, it can provide efficient and reliable power transfer. By dynamically adjusting the number of coils and system compensation parameters, it can effectively compensate for the mutual inductance changes caused by magnetic field offset, ensuring that the system can maintain stable constant voltage output and efficient wireless power transfer under different environmental conditions. It is particularly suitable for dynamic scenarios such as USVs, ensuring high efficiency and stability during battery charging.

[0021] As a specific embodiment, the inverter circuit can be implemented using a half-bridge inverter circuit, an inverter circuit, or a DC-AC converter with inverter characteristics; the rectifier circuit can be implemented using a synchronous rectifier circuit, a full-wave rectifier circuit, or a bridge rectifier circuit; the DC-DC converter can be a DC-DC converter such as Buck-Boost to complete the conversion of the output voltage level so that it meets the battery voltage level requirements.

[0022] In a preferred embodiment, the inverter circuit includes an H-bridge topology consisting of four semiconductor devices with switching characteristics. In practice, the semiconductor devices with switching characteristics are silicon carbide MOSFETs. MOSFETs S1 and S2 are connected in series to form the left half-bridge, and MOSFETs S3 and S4 are connected in series to form the right half-bridge. Both ends of the left and right half-bridges are connected to the positive and negative terminals of the power supply. The midpoints of the left and right half-bridges serve as the AC output terminals of the inverter circuit, used to convert the power supply into high-frequency AC power.

[0023] As a specific embodiment, Figure 2 shows a circuit diagram of the MCR-WPT topology based on the LCC-S compensation network. The inverter circuits S1 to S4 employ SiC N-channel MOSFETs to convert the power supply from DC to high-frequency AC. SiC (silicon carbide) MOSFETs have lower on-resistance, lower switching losses, and higher voltage withstand capability than traditional Si MOSFETs, contributing to improved overall system efficiency.

[0024] The inverter circuit output voltage is regulated using phase-shifted full-bridge control technology. By controlling the phase difference (0-180°) between the drive signals of the left and right half-bridges, the conduction timing of the switching transistors is adjusted, thereby changing the duty cycle and RMS value of the AC output waveform. The larger the phase shift angle, the lower the output voltage amplitude; the smaller the phase shift angle, the higher the output voltage amplitude.

[0025] Since the coupling coefficient of wireless power transfer is typically low, direct coupling leads to low power transfer efficiency. Therefore, a compensation network is needed to improve the system's power transfer capability. Simultaneously, during wireless charging, the load usually changes non-linearly. Different USVs (Unmanned Surface Vehicles) have different charging levels, and their power transfer is susceptible to power loss and voltage level variations due to changes in the coupling coefficient. Therefore, a constant voltage compensation network is required to achieve a constant voltage output independent of the load. This system designs a reconfigurable coil MCR-WPT (Magnetic Coupling Resonance WPT) compensation network, employing an LCC-S compensation network based on a reconfigurable coil as the compensation network structure. This network provides a constant voltage output independent of the load, and its secondary side has a simple compensation structure, enabling efficient charging of USVs at different voltage levels and enhancing the system's anti-offset capability.

[0026] In a preferred embodiment, the rectifier circuit adopts a full-bridge and half-bridge rectifier topology composed of semiconductor switching devices with switching characteristics; specifically, it adopts a full-bridge rectifier topology composed of four Schottky rectifier diodes.

[0027] As shown in Figure 2, the rectifier circuits Q1 to Q4 use Schottky rectifier diodes, which can reduce the switching losses of the system and improve the transmission efficiency of the system. The four Schottky diodes (Q1-Q4) form a full-bridge topology, which converts the high-frequency AC power output from the secondary LCC-S compensation network into DC power.

[0028] In a preferred embodiment, the primary side of the LCC-S compensation network based on reconfigurable coil includes a resonant inductor connected in series with a resonant capacitor. The input terminal of the primary side is connected to the output terminal of the inverter circuit, thereby achieving constant current output on the primary side independent of the load. The secondary side of the LCC-S compensation network includes a series capacitor and the coil self-inductance, and the output terminal is connected to the rectifier circuit, thereby achieving constant voltage output on the secondary side.

[0029] As a preferred embodiment, as shown in Figure 3, Figure 3 illustrates the schematic diagram of an MCR-WPT network based on reconfigurable coils, where L f C f For the primary resonant inductor and capacitor, C pi L pi and C si L si (i=1, 2, 3) are the primary and secondary compensation capacitors and equivalent self-inductance, respectively, and the primary and secondary coils are connected in series. When the switching switch S... ir At this time, the primary and secondary coils of the reconfigurable system can be connected to different numbers of primary and secondary coils, thereby realizing flexible switching between different operating modes. This can be expressed by the formula: the equivalent self-inductance of the primary side is L. p1 =L t1 (S in Figure 3) 1r (closed), L p2 =L t1 +L t2 (S in Figure 3) 2r (closed), L p3 =L t1 +L t2 +L t3 (S in Figure 3) 3r (Closed), the equivalent self-inductance of the corresponding secondary side is L. s1 =L r1 L s2 =L r1 +L r2 L s3 =L r1 +L r2 +L r3 .

[0030] Specifically, both the primary and secondary coils will be wound using coils of the same size. Therefore, if L t1 =L t2 =L t3 =L p L r1 =L r2 =L r3 =L s If M1=M2=M3=M, then: when the system is in different operating states, the system's equivalent self-inductance L px L sxAs shown in equation (1).

[0031] (1) Wherein, M p M s M ps These represent the self-coupling and cross-coupling of the primary and secondary coils, respectively; x (x=1, 2, 3) represents the number of coils connected to the system in different operating states.

[0032] Because the transmitting and receiving coils are spaced far apart and both employ a shielded design, the cross-coupling between the primary and secondary coils can be ignored in this analysis. When the switch S... ir The mutual inductance of MCR-WPT is shown in Table 1.

[0033] Table 1 Self-inductance and mutual inductance of compensation network under different switching modes If the system is in a resonant state, then the equivalent self-inductance L based on the LCC-S compensation network with reconfigurable coils is... px With C pi The relationship shown in equation (2) should be satisfied: (2) At this time, according to KVL (Kirchhoff's Voltage Law) and equation (2), the primary input current I ix Secondary output current I ox Primary-side output current I px Satisfy the relationship shown in equation (3): (3) From equation (3), it can be seen that the primary side output current I px Only with input voltage V i and resonant inductance L f It is related to the load R and is independent of the coil self-inductance, i.e., I p1 =I p2 =I p3 =I p Meanwhile, it can be known that the voltage gain G vx Current gain G ix They are respectively: (4) Therefore, from equations (2) to (4), we can know that the input power P inx Output power P outx and transmission efficiency η x As shown in equation (5): (5) Based on the above analysis, if the equivalent series resistance (ESR) of the coil is ignored, and the resonant inductance L is fixed... f Parameters and constant pressure V i Power supply, this output voltage V ox With load R L Irrelevant, related to mutual induction Mx It is in a direct proportional relationship. Therefore, a reconfigurable coil can be adopted to regulate the output voltage level and improve the compatibility of the system.

[0034] Meanwhile, it can be seen from the analysis of the LCC-S compensation network that if both the primary and secondary sides are in the resonant state, not only can the output voltage of the secondary side be made independent of the load, the zero-phase-angle (ZPA) and pure resistive output be achieved, but also the transmission efficiency can be improved and the output characteristics of the system can be improved.

[0035] From the above analysis, it can be seen that fixing the resonant inductor L f parameters and adopting a constant voltage V i power supply, the output voltage V ox is independent of the load R L and is in a direct proportional relationship with the mutual inductance M x ; if the resonant inductor L [[ID=I8]] f parameters and the mutual inductance M x are fixed, the output voltage V ox is independent of the load R L and is in a direct proportional relationship with the input voltage V i .

[0036] Furthermore, Fig. 4 shows the flowchart of the working mode switching, and the three working modes are specifically as follows: Mode 1: 0 < v cd < v1, both the primary and secondary sides are connected to Coil 1, and Working Mode 1 is adopted, and the system is in the resonant state; Mode 2: v1 ≤ v cd < v2, both the primary and secondary sides are connected to Coil 1 and Coil 2, and Working Mode 2 is adopted, and the system is in the resonant state; Mode 3: v2 ≤ v cd < v3, both the primary and secondary sides are connected to Coil 1, Coil 2 and Coil 3, and Working Mode 3 is adopted, and the system is in the resonant state.

[0037] To describe the system of this embodiment more clearly, the connection relationship of this system is shown through the energy transmission path: Power supply → Inverter circuit → LCC-S primary network → Reconfigurable magnetic coupling mechanism (primary side) → Anti-offset rounded trapezoidal coil (secondary side) → LCC-S secondary network → Rectifier circuit → DC-DC converter → Unmanned ship battery.

[0038] During dynamic regulation, the output voltage is preferentially regulated by the phase shift angle. If the phase shift regulation is insufficient, the number of coils is switched to increase the mutual inductance value.

[0039] Example 2: During wireless charging, unmanned surface vessels are susceptible to displacement due to factors such as wind and waves. This causes dynamic changes in the facing distance, angle, and area of ​​the ship-side coil and shore-side coil, leading to variations in the coupling coefficient of the magnetic coupling mechanism. Different magnetic coupling mechanisms exhibit different magnetic field distributions. Therefore, the magnetic coupling coil needs to be optimized to improve the uniformity of the magnetic field distribution, thereby enhancing the unmanned vessel's resistance to displacement during wireless charging.

[0040] In a preferred embodiment, the primary and secondary sides of the LCC-S compensation network based on reconfigurable coils both employ three sets of reconfigurable rounded trapezoidal coils. The number of coils connected to the system is dynamically adjusted by a switching switch to compensate for changes in mutual inductance caused by offset.

[0041] As a preferred embodiment, the method for determining the optimized parameters of the rounded trapezoidal coil includes: modeling the magnetic field distribution of a single-turn trapezoidal coil based on the Biot-Savart law, and analyzing the influence of inner diameter, tilt angle, turn spacing, and rounded radius on the spatial magnetic field distribution; further optimizing the inner diameter, outer diameter, tilt angle, turn spacing, rounded radius, and number of turns of the multi-turn magnetic coupler; constructing a simulation model of the multi-turn rounded trapezoidal magnetic coupling mechanism, verifying and analyzing the influence of different parameter magnetic coupling coil models on self-inductance, mutual inductance, and coupling coefficient, and determining the optimal magnetic coupling coil parameters.

[0042] Specifically, to analyze and simplify the magnetic field distribution of the trapezoidal coil, a single-turn trapezoidal coil model as shown in Figure 5 is used for magnetic field analysis. Its transmitting coil has a length of 2n, a width of 2m, and a base angle of θ. O1 is the center of the rectangular coil and is symmetrical about the x-axis. The distance between the receiving coil and the transmitting coil is h, and P is a point on the receiving coil at distances a and b from the x-axis and y-axis, respectively.

[0043] If the current flowing through the single-turn rounded rectangular transmitting coil is I t At this point, according to the Biot-Savart law, the magnetic field produced by the current flowing through the conductor is: in, For current, These are tiny line elements in the direction of the current element. The vector from the current element to point P The modulus, μ0, is the free permeability, with a value of 4π × 10⁻⁶. -7 T·m·A -1 .

[0044] Through reasoning and analysis, it can be seen that as the inner diameter n0 of the coil increases, B z,A1B1 First increase then decrease, and in n eThe maximum value is obtained at point P; at this point, the analytical curve of magnetic induction intensity with tilt angle θ and coil inner diameter n0 is shown in Figure 6. As can be seen from Figure 6, as the coil size n0 and tilt angle θ0 continuously increase, the line segment A1B1 at point B in space P reaches its maximum value. z,A1B1_Max This will reduce [the risk]. In this embodiment, the magnetic coupling mechanism is selected with an outer diameter of 440mm*350mm, an inner diameter of 120mm*94mm, and an inclination angle of 1.22rad. Experiments have shown that the magnetic coupling mechanism can simultaneously possess good anti-displacement properties at this time.

[0045] Furthermore, based on this size of the magnetic coupling mechanism, the parameters of the magnetic coupling mechanism and the magnetic field distribution are analyzed by parameters such as the turn spacing and the fillet radius. The parameter equivalent model and optimization process are shown in Figure 7 and Figure 8, respectively.

[0046] The number of coil turns was simulated and analyzed from 1 to 30 turns based on the constraints of a trapezoidal coil with an outer diameter of 440mm*350mm and an inner diameter of 120mm*96mm, and a wire diameter of 3.4mm. The step size was 1 turn, and the transmission distance between the transmitting coil and the receiving coil was 100mm.

[0047] As the number of coil turns increases, the self-inductance, mutual inductance, and coupling coefficient of the coil will tend to stabilize. However, increasing the number of coil turns not only increases the weight, volume, and cost of the system, but also increases the eddy current loss of the magnetic coupling mechanism. Therefore, based on the actual space size and transmission performance indicators, this embodiment selects a 20-turn trapezoidal coil as the optimization target for the magnetic coupling mechanism.

[0048] To improve the coil's resistance to deflection, the coil's turn spacing and corner radius will be optimized. When the coil's outer diameter is 440mm*350mm, inner diameter is 120mm*96mm, number of turns is 20, and wire diameter is 3.4mm, the selected coil's maximum horizontal turn spacing is 6.8mm, maximum vertical turn spacing is 3.2mm, and maximum corner radius is 70mm.

[0049] Example 3: The navigation system, communication equipment, and measurement sensors carried by USVs have the characteristics of strong real-time performance, high mobility, high accuracy in depth and current measurement, and ease of use. However, they are susceptible to electromagnetic interference, which can cause communication delays, data loss, and damage to electronic equipment.

[0050] Therefore, designing the electromagnetic shielding structure for the magnetic coupling mechanism can effectively improve the safety, reliability, and lifespan of USVs systems. This embodiment, in accordance with the limits derived by the International Commission on Non-Ionizing Protection (ICNIRP), uses finite element analysis software to analyze different shielding materials, structures, and locations on the receiving and transmitting coils, ensuring that the electromagnetic shielding structure meets the ICNIRP limits and thus improving the reliability of USVs equipment.

[0051] It should be noted that while single-layer and double-layer shielding can reduce the magnetic flux density at the x and y observation points, they also increase the magnetic flux density at the z observation point to some extent. Double-layer shielding reduces the central magnetic flux density at the x and y observation points, but the edges remain at a relatively high level. Meanwhile, although the conventional aluminum plate + ferrite shielding method effectively reduces the magnetic flux density at the observation points and meets the ICNIRP-2010 requirement of no more than 27 μT, the aluminum plate shielding causes a sharp decrease in the mutual inductance, self-inductance, and coupling coefficient of the magnetic coupling mechanism. Therefore, it is necessary to introduce high-permeability materials to improve the characteristics of the magnetic coupling mechanism. While nanocrystalline phases have higher permeability than ferrite, and thus improve the characteristics of the magnetic coupling mechanism to some extent, they also increase the magnetic flux density at the observation points. Therefore, a hybrid shielding and structural optimization design are needed to improve the characteristics of the magnetic coupling mechanism and reduce the magnetic flux density at the observation points.

[0052] In a preferred embodiment, the rounded trapezoidal magnetic coupling mechanism has a hybrid electromagnetic shielding layer; the hybrid electromagnetic shielding layer includes a ferrite layer and a nanocrystalline layer that are closely attached to the surface of the coil, and the two are placed alternately.

[0053] As shown in Figure 9, the hybrid electromagnetic shielding layer adopts a multi-layer hybrid shielding method of ferrite + aluminum plate + nanocrystal to improve the parameters of the magnetic coupling mechanism and reduce the leakage magnetic flux of the magnetic coupling mechanism.

[0054] To verify the shielding effect of this embodiment, this application compared the parameters of the magnetic coupling mechanism with different shielding methods. The comparison results are shown in Table 2: Table 2 Parameters of magnetic coupling mechanism with different shielding methods As shown in Table 2, compared to unshielded systems, single-layer shielding, double-layer shielding, and hybrid shielding effectively improve the parameters of the magnetic coupling mechanism. The self-inductance increases by 146.81 μH, 83.94 μH, 19.15 μH, and 162.29 μH, respectively; the mutual inductance increases by 91.3 μH, 55.81 μH, 16.85 μH, and 99.17 μH, respectively; and the coupling coefficient increases by 0.139, 0.11, 0.056, and 0.141, respectively. Furthermore, with hybrid shielding, compared to rounded trapezoidal ferrite shielding, the self-inductance, mutual inductance, and coupling coefficient increase by 15.48 μH, 7.87 μH, and 0.002, respectively. In conclusion, hybrid shielding effectively improves the parameters of the magnetic coupling mechanism.

[0055] Example 4: This embodiment of the invention also provides a method for anti-drift wireless power transmission of unmanned surface vessels based on a reconfigurable trapezoidal magnetic coupling mechanism. This method is implemented using the anti-drift wireless power transmission system for unmanned surface vessels based on a reconfigurable trapezoidal magnetic coupling mechanism as described above. The method includes: converting direct current (DC) to high-frequency alternating current (AC) via an inverter circuit; dynamically adjusting the coil combination using the reconfigurable magnetic coupling mechanism to compensate for voltage fluctuations and impedance matching problems caused by mutual inductance changes due to drift; uniformly distributing the magnetic field using a rounded trapezoidal magnetic coupling mechanism to improve drift resistance; and outputting DC power to the unmanned surface vessel's battery via a rectifier circuit and a DC-DC converter.

[0056] As a preferred embodiment, a reconfigurable magnetic coupling mechanism is used to dynamically adjust the coil combination to compensate for voltage fluctuations caused by changes in mutual inductance due to displacement. This includes: when the hull shifts, determining whether the voltage level and output power meet the usage requirements; if they do, reducing the phase shift angle of the inverter circuit and increasing the output voltage.

[0057] Figure 10 shows a flowchart illustrating the control and regulation process of this system. Referring to Figure 3, an inverter circuit is used to control the output voltage. First, maintain V... dc The output voltage V remains constant when the mutual inductance M changes. o The voltage will change accordingly; if M increases, the inverter output voltage can be adjusted by increasing the phase shift angle of the inverter circuit, as shown in Figure 3, V. i If M decreases, then the phase shift angle of the inverter circuit is reduced to achieve the desired output voltage V. o The increase.

[0058] In some embodiments, the output voltage is controlled by switching the number of connected coils. dc If the mutual inductance M remains constant, and the phase shift angle is reduced to 0 (when the inverter circuit output voltage is at its maximum), the output voltage still does not meet the V requirement. o The voltage should be switched at this time by switch S. ir Adjust the number of magnetic coupling mechanisms in the access system, that is, increase the mutual inductance M by adjusting the number of magnetic coupling mechanisms.

[0059] In summary, the unmanned vessel anti-offset wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism provided by this invention solves the following technical problems: (1) To address the problem of power reduction and voltage level change caused by the offset of the USVs MCR-WPT system, a reconfigurable coil MCR-WPT compensation network based on the LCC-S compensation network is designed. This compensation network can not only flexibly adjust the magnetic coupling mechanism for USVs with different voltage levels to achieve efficient charging, but also enhance the system's anti-offset capability; (2) To address the problem of USVs being susceptible to offset due to factors such as wind and waves, an anti-offset rounded trapezoidal high-efficiency magnetic coupling mechanism is designed, and the uniform distribution of the magnetic field of the rounded trapezoidal coil is achieved through parameter optimization, which makes up for the deficiency of insufficient magnetic field control in the charging area of ​​traditional coils; (3) To address the electromagnetic safety problem of the USVs MCR-WPT system, by introducing nanocrystalline materials and optimizing the design of the hybrid electromagnetic shielding layer structure, the problem of reduced coil inductance parameters and coupling coefficient or magnetic induction intensity exceeding the derived limit standard caused by the leakage magnetic shielding of the coupling coil by the traditional shielding layer is solved.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A drift-resistant wireless power transfer system for unmanned surface vessels based on a reconfigurable trapezoidal magnetic coupling mechanism, characterized in that, include: The MCR-WPT topology based on the LCC-S compensation network includes an inverter circuit, an LCC-S compensation network based on reconfigurable coils, a rectifier circuit, and a DC-DC converter. The input of the inverter circuit is connected to the power supply to convert the power supply into high-frequency AC power. The LCC-S compensation network based on reconfigurable coils includes a primary side and a secondary side. The input of the primary side is connected to the output of the inverter circuit. An anti-offset magnetic coupling mechanism is connected between the primary and secondary sides. The output of the secondary side is connected to the rectifier circuit to dynamically switch the number of coils and optimize the system compensation parameters, compensating for mutual inductance changes and impedance mismatch caused by offset, so as to maintain constant voltage output and efficient and stable transmission of the system. The rectifier circuit is used to convert high-frequency AC power into DC power, and adopts one of the following: synchronous rectifier circuit, full-wave rectifier circuit, or bridge rectifier circuit; the DC-DC converter is used to complete the conversion of the output voltage level to meet the battery voltage level requirements and charge the unmanned vessel battery.

2. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 1, characterized in that, The primary side of the LCC-S compensation network based on reconfigurable coils includes a resonant inductor connected in series with a resonant capacitor. The input terminal of the primary side is connected to the output terminal of the inverter circuit to achieve constant current output on the primary side. The secondary side of the LCC-S compensation network includes a series capacitor and the coil self-inductance. The output terminal is connected to the input terminal of the rectifier circuit, and the output terminal of the rectifier circuit is connected to the DC-DC converter to achieve constant voltage output on the secondary side.

3. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 2, characterized in that, Both the primary and secondary coils are wound with coils of the same size; when the system is in a resonant state, the equivalent self-inductance L of the primary side based on the LCC-S compensation network of the reconfigurable coil is... px With compensation capacitor C pi Satisfying the relation: Among them, L f C f These are the primary resonant inductor and capacitor, respectively, C pi L px and C si L sx (x=1, 2, 3) are the primary and secondary side compensation capacitors and equivalent self-inductance, respectively.

4. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 2, characterized in that, The LCC-S compensation network based on reconfigurable coils uses three sets of reconfigurable rounded trapezoidal coils on both the primary and secondary sides. The number of coils connected to the system is dynamically adjusted by a switching switch to compensate for changes in mutual inductance caused by offset.

5. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 4, characterized in that, The method for determining the optimized parameters of the rounded trapezoidal coil includes: modeling the magnetic field distribution of a single-turn trapezoidal coil based on the Biot-Savart law, optimizing the inner diameter, tilt angle, turn spacing, rounded radius, and number of turns; verifying the influence of different parameter magnetic coupling coil models on self-inductance, mutual inductance, and coupling coefficient through simulation, and determining the optimal magnetic coupling coil parameters.

6. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 4, characterized in that, The rounded trapezoidal magnetic coupling mechanism has a hybrid electromagnetic shielding layer; the hybrid electromagnetic shielding layer includes a ferrite layer and a nanocrystalline layer that are closely attached to the surface of the coil and are placed alternately, the outer side of the ferrite layer and the nanocrystalline layer is an aluminum plate layer, and the center of the aluminum plate layer is embedded with a nanocrystalline layer.

7. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 1, characterized in that, The inverter circuit includes: an H-bridge topology consisting of four semiconductor devices with switching characteristics; a left half-bridge formed by connecting devices S1 and S2 in series, and a right half-bridge formed by connecting devices S3 and S4 in series. Both ends of the left and right half-bridges are connected to the positive and negative terminals of the power supply. The midpoints of the left and right half-bridges serve as the AC output terminals of the inverter circuit, used to convert the power supply into high-frequency AC power.

8. The unmanned surface vessel anti-drift wireless power transfer system based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 1, characterized in that, The rectifier circuit adopts a full-bridge and half-bridge rectifier topology composed of semiconductor switching devices with switching characteristics.

9. A method for offset-resistant wireless power transfer of unmanned surface vessels based on a reconfigurable trapezoidal magnetic coupling mechanism, characterized in that, The application of the unmanned vessel anti-drift wireless power transmission system based on a reconfigurable trapezoidal magnetic coupling mechanism as described in any one of claims 1-8 includes: converting DC power into high-frequency AC power through an inverter circuit; dynamically adjusting the coil combination using the reconfigurable magnetic coupling mechanism to compensate for voltage fluctuations and impedance mismatch caused by mutual inductance changes due to drift; and completing voltage level conversion and outputting DC power to the unmanned vessel battery through a rectifier circuit and a DC-DC converter.

10. The unmanned surface vessel anti-drift wireless power transfer method based on a reconfigurable trapezoidal magnetic coupling mechanism according to claim 9, characterized in that, The reconfigurable magnetic coupling mechanism is used to dynamically adjust the coil combination to compensate for voltage fluctuations and impedance mismatches caused by mutual inductance changes due to hull offset. This includes: when the hull offsets, determining whether the voltage level and output power meet the usage requirements; if they do, reducing the phase shift angle of the inverter circuit to increase the output voltage; and if reducing the phase shift angle of the inverter circuit cannot meet the voltage level or output power requirements when the hull offsets, adjusting the number of magnetic coupling coils to compensate for the system's voltage and power.

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