AUV three-phase wireless charging system based on segmented arc coupler

Abstract

A three-phase wireless charging system for AUVs based on a segmented arc coupler belongs to the technical field of underwater wireless power transmission. The present invention addresses the problem that the magnetic field generated by the existing three-phase magnetic coupling mechanism is uneven during rotational offset, causing large fluctuations in the system output power. The segmented arc coupler includes three arc-shaped transmitting coils and a cylindrical receiving coil, and the three arc-shaped transmitting coils are evenly distributed around the circumferential direction of the receiving coil; the three arc-shaped transmitting coils are arranged on the outer surface of the AUV hull, and the receiving coil is arranged on the inner surface of the AUV hull; the excitation currents of the three arc-shaped transmitting coils are controlled separately by an excitation source; the excitation current amplitudes of the arc-shaped transmitting coil one and the arc-shaped transmitting coil two change according to the cosine and sine laws respectively, and the excitation current amplitude of the arc-shaped transmitting coil three remains unchanged; the excitation current phase difference between the arc-shaped transmitting coil one and the arc-shaped transmitting coil two and the arc-shaped transmitting coil three is 90°. The present invention is used for underwater wireless charging of AUVs.

Description

Technical Field

[0001] The invention relates to an AUV three-phase wireless charging system based on a segmented arc coupler, belonging to the technical field of underwater wireless power transmission. Background Art

[0002] Since the 21st century, autonomous underwater vehicles (AUVs) have been widely used in civil, military, and commercial applications due to their numerous advantages, including autonomy, stealth, environmental adaptability, and deployability. In the civilian sector, they play an increasingly important role in seabed exploration, underwater rescue, salvage, and marine scientific research. In the military sector, they can be used for underwater submarine warfare and anti-submarine warfare, mine countermeasures, marine reconnaissance and surveillance, intelligence gathering, information communications, and target attack. These vehicles have greatly expanded the operational scope of both surface and underwater combat systems and are a key underwater combat equipment development focus for major naval nations worldwide.

[0003] To improve the endurance of AUVs and address the drawbacks of traditional AUV charging methods, underwater wireless charging technology has emerged. AUVs can autonomously return to an underwater base station for recharging and data exchange as needed, significantly extending their endurance while also improving charging safety and flexibility.

[0004] Currently, in the field of underwater wireless charging, domestic and international researchers are primarily focused on the design of coupling mechanisms with various special shapes. Considering various factors, such as the requirements for AUV installation and docking, and resistance to current impact, some researchers have proposed couplers with offset adaptability, such as conical, arc-shaped, segmented ring-shaped, and arc-shaped solenoids. However, these couplers are only resistant to offset in the axial or radial directions, and their resistance to rotational offset is poor. To address these issues, the article "A Rotation-Resilient Wireless Charging System for Lightweight Autonomous Underwater Vehicles" in the journal IEEE Transactions on Vehicular Technology discloses a three-phase magnetic coupling mechanism to improve the offset adaptability of underwater wireless charging systems. However, this approach still has the following shortcomings: ① The magnetic field configuration at the center of the AUV hull is not optimized; ② The excessive size of the coupler increases the weight of the AUV, which is not conducive to improving the system's power density; ③ During the rotational offset of the AUV hull due to ocean current fluctuations, the magnetic field generated is non-uniform, resulting in large fluctuations in the system's output power, which may even fail to meet charging requirements.

[0005] At present, it can be found from the publicly available information that in the field of underwater wireless charging, single-phase power supply is the main method, and three-phase power supply is rarely reported; and there are no reports on the application of omnidirectional wireless charging technology and its uniform magnetic field modulation method to AUV wireless charging systems. Summary of the Invention

[0006] In order to solve the problem that the existing three-phase magnetic coupling mechanism generates an uneven magnetic field when rotating and offsetting, causing large fluctuations in the system output power, the present invention provides an AUV three-phase wireless charging system based on a segmented arc coupler.

[0007] The present invention provides an AUV three-phase wireless charging system based on a segmented arc coupler, comprising a segmented arc coupler; the segmented arc coupler comprises three identical arc-shaped transmitting coils and a cylindrical receiving coil,

[0008] The three arc-shaped transmitting coils are evenly distributed on the periphery of the circumference of the cylindrical receiving coil; the three arc-shaped transmitting coils are arranged on the outer surface of the AUV hull, and the cylindrical receiving coil is arranged on the inner surface of the AUV hull;

[0009] The excitation currents of the three arc-shaped transmitting coils are controlled separately by an excitation source; the three arc-shaped transmitting coils are arc-shaped transmitting coil 1, arc-shaped transmitting coil 2, and arc-shaped transmitting coil 3, so that the excitation current amplitudes of arc-shaped transmitting coil 1 and arc-shaped transmitting coil 2 change according to the cosine and sine laws, respectively, while the excitation current amplitude of arc-shaped transmitting coil 3 remains unchanged; the phase difference between the excitation currents of arc-shaped transmitting coil 1 and arc-shaped transmitting coil 2 and arc-shaped transmitting coil 3 is 90 degrees, forming a uniform spatial rotating magnetic field inside the AUV hull.

[0010] According to the AUV three-phase wireless charging system based on the segmented arc coupler of the present invention, the three segmented arc transmitting coils are driven by three independent half-bridge inverter bridges in the three-phase voltage-type inverter using a phase-shift modulation strategy.

[0011] According to the present invention, the AUV three-phase wireless charging system based on the segmented arc coupler includes a power transmitting end and a power receiving end. The power transmitting end includes a DC voltage source, a three-phase voltage-type inverter, a transmitter compensation network and three-segment arc-shaped transmitting coils; the power receiving end includes a cylindrical receiving coil, a receiver compensation network, a rectifier, an output capacitor and a power battery pack.

[0012] The positive electrode and negative electrode of the DC voltage source are respectively connected to the positive electrode connection terminal and the negative electrode connection terminal of the three-phase voltage type inverter;

[0013] The transmitter compensation network is a three-phase compensation network. Each phase of the compensation network includes a transmitting compensation inductor, a transmitting compensation capacitor 1, and a transmitting compensation capacitor 2. The three single-phase AC output terminals of the three-phase voltage-type inverter are respectively connected to one end of the transmitting compensation inductor of each phase compensation network. The other end of the transmitting compensation inductor is simultaneously connected to the positive electrodes of transmitting compensation capacitor 1 and transmitting compensation capacitor 2. The negative electrode of each transmitting compensation capacitor 2 is correspondingly connected to the same-name end of a segment of an arc-shaped transmitting coil. The negative electrode of each transmitting compensation capacitor 1 and the opposite-name end of each segment of the arc-shaped transmitting coil are simultaneously connected to the negative connection terminal of the three-phase voltage-type inverter.

[0014] The cylindrical receiving coil is connected to the rectifier through the receiver compensation network. The DC power output by the rectifier is transferred to the power battery pack through the output capacitor for storage.

[0015] According to the AUV three-phase wireless charging system based on the segmented arc coupler of the present invention, the circuit structure of the power transmitter is:

[0016] The three arc-shaped transmitting coils are arc-shaped transmitting coils L PA , arc-shaped transmitting coil L PB and arc-shaped transmitting coil L PC ;

[0017] The three-phase voltage-type inverter includes an A-phase inverter bridge, a B-phase inverter bridge, and a C-phase inverter bridge. The A-phase inverter bridge includes a switch tube S1, an anti-parallel freewheeling diode D1 of the switch tube S1, a switch tube S2, and an anti-parallel freewheeling diode D2 of the switch tube S2; the B-phase inverter bridge includes a switch tube S3, an anti-parallel freewheeling diode D3 of the switch tube S3, a switch tube S4, and an anti-parallel freewheeling diode D4 of the switch tube S4; the C-phase inverter bridge includes a switch tube S5, an anti-parallel freewheeling diode D5 of the switch tube S5, a switch tube S6, and an anti-parallel freewheeling diode D6 of the switch tube S6;

[0018] The drains of the switch tubes S1, S3 and S5 are connected to each other as positive terminals and connected to the DC voltage source V DC The positive electrode of the switch tube S2, the switch tube S4 and the switch tube S6 are connected to each other as the negative electrode connection terminal and the DC voltage source V DC The source of the switch tube S1 is connected to the drain of the switch tube S2, and the connection point A is used as the output terminal of the A-phase AC power; the source of the switch tube S3 is connected to the drain of the switch tube S4, and the connection point B is used as the output terminal of the B-phase AC power; the source of the switch tube S5 is connected to the drain of the switch tube S6, and the connection point C is used as the output terminal of the C-phase AC power;

[0019] The A-phase compensation network of the transmitter compensation network includes the transmitter compensation inductor L FA , Transmitter compensation capacitor - C FA and the emission compensation capacitor CPA ;B phase compensation network includes transmitter compensation inductor L FB , Transmitter compensation capacitor - C FB and the emission compensation capacitor C PB ; The C-phase compensation network includes the transmitter compensation inductor L FC , Transmitter compensation capacitor - C FC and the emission compensation capacitor C PC ; The A-phase AC output terminal is connected to the transmitter compensation inductor L FA One end of the transmitter compensation inductor L FA The other end is connected to the transmitter compensation capacitor C FA and the emission compensation capacitor C PA The positive pole of the emission compensation capacitor is C PA The negative pole of the arc-shaped transmitting coil L is connected PA The same-name end, the transmitter compensation capacitor C FA The negative pole and arc-shaped transmitting coil L PA The opposite end of the three-phase voltage inverter is connected to the negative terminal at the same time; the B-phase AC output terminal is connected to the transmitter compensation inductor L FB One end of the transmitter compensation inductor L FB The other end is connected to the transmitter compensation capacitor C FB and the emission compensation capacitor C PB The positive pole of the emission compensation capacitor is C PB The negative pole of the arc-shaped transmitting coil L is connected PB The same-name end, the transmitter compensation capacitor C FB The negative pole and arc-shaped transmitting coil L PB The opposite end of the three-phase voltage inverter is connected to the negative terminal at the same time; the C-phase AC output terminal is connected to the transmitter compensation inductor L FC One end of the transmitter compensation inductor L FC The other end is connected to the transmitter compensation capacitor C FC and the emission compensation capacitor C PC The positive pole of the emission compensation capacitor is C PC The negative pole of the arc-shaped transmitting coil L is connected PC The same-name end, the transmitter compensation capacitor C FC The negative pole and arc-shaped transmitting coil L PC The opposite-name ends of the three-phase voltage-type inverter are connected to the negative terminal of the three-phase voltage-type inverter at the same time.

[0020] According to the AUV three-phase wireless charging system based on the segmented arc coupler of the present invention, the circuit structure of the power receiving end is:

[0021] The receiver compensation network includes the receiver compensation capacitor C S1 , receiver compensation capacitor C S2, receiver compensation inductor L S1 and relay Q; the rectifier includes switch tube S7, switch tube S8, diode D7 and diode D8;

[0022] The drain of the switch tube S7 is connected to the cathode of the diode D7, the source of the switch tube S7 is connected to the drain of the switch tube S8, the source of the switch tube S8 is connected to the anode of the diode D8, and the cathode of the diode D8 is connected to the anode of the diode D7; the anode of the diode D7 serves as the positive input terminal of the rectifier, and the drain of the switch tube S8 serves as the negative input terminal of the rectifier;

[0023] Cylindrical receiving coil L S The same-name end of the receiver is connected to the compensation capacitor C S1 The positive pole of the receiver compensation capacitor C S1 The negative pole of the receiver is connected to the compensation inductor L S1 One end of the receiver compensation inductor L S1 The other end is connected to the positive input terminal of the rectifier through the relay Q; the receiver compensation capacitor C S1 The negative pole of the receiver is connected to the compensation capacitor C S2 The positive pole of the receiver compensation capacitor C S2 The negative pole is connected to the negative input terminal of the rectifier; the cylindrical receiving coil L S The opposite end of the diode D7 is connected to the source of the switch tube S8; the output capacitor C is connected between the cathode of the diode D7 and the anode of the diode D8. O , power battery pack and output capacitor C O in parallel.

[0024] According to the AUV three-phase wireless charging system based on segmented arc coupler of the present invention, the inductance values ​​of the three segmented arc transmitting coils are set to be equal, all of which are L P ; Three arc-shaped transmitting coils and cylindrical receiving coil L S The mutual inductance of the three transmitter compensation inductors is equal, all are M; the inductance values ​​of the three transmitter compensation inductors are equal, all are L F The capacitance values ​​of the three transmitter compensation capacitors are equal, all C F The capacitance values ​​of the three transmitter compensation capacitors are equal, all C P ;U A is the effective value of the output voltage of the A-phase inverter bridge; R EQ is the equivalent input AC resistance of the rectifier;

[0025] In the constant current charging mode, the A-phase compensation network and the receiver compensation network are equivalent to a bilateral LCC compensation topology, and the current flowing through the receiver compensation inductor L S1 The current i L1 Expressed as:

[0026]

[0027] Where ω is the system operating angular frequency;

[0028] The output power P of the charging system out-CC for:

[0029]

[0030] According to the AUV three-phase wireless charging system based on the segmented arc coupler of the present invention, in the constant voltage charging mode, the A-phase compensation network and the receiver compensation network are equivalent to the LCC-S compensation topology, and the output voltage U2 of the charging system is expressed as:

[0031]

[0032] Output power P of the charging system out-CV for:

[0033]

[0034] According to the AUV three-phase wireless charging system based on the segmented arc coupler of the present invention, the smooth switching condition of the charging system from the constant current charging mode to the constant voltage charging mode is:

[0035]

[0036] Where R BAT is the resistance of the power battery pack.

[0037] According to the AUV three-phase wireless charging system based on segmented arc coupler of the present invention, the receiver compensation capacitor C S1 and receiver compensation capacitor C S2 The capacitance value is determined by the following formula:

[0038]

[0039] According to the AUV three-phase wireless charging system based on segmented arc coupler of the present invention, the capacitance value C of the three transmitting compensation capacitors is F And the capacitance value of the three transmitter compensation capacitors C P Determined according to the following formula:

[0040]

[0041] Among them C S For intermediate variables:

[0042]

[0043] Beneficial effects of the invention: The present invention provides an AUV three-phase wireless charging system, which can modulate to form a uniform magnetic field through the control of the excitation source, thereby improving the anti-rotational deviation capability of the AUV wireless charging system, suppressing the magnetic field at the center of the AUV hull, and reducing the output power fluctuation of the system, thereby better meeting the battery charging needs.

[0044] The system of the present invention generates a three-dimensional rotating magnetic field by controlling the excitation current of three arc-shaped transmitting coils. The synthesized magnetic field vector scans and covers any direction of a cylindrical area over time. Regardless of the angular offset of the receiving coil, the magnetic field generated at some time passes through the receiving coil, realizing omnidirectional wireless power transmission, thereby achieving the purpose of resisting rotational offset and suppressing output power fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the relative positions of the arc-shaped transmitting coil and cylindrical receiving coil of the segmented arc coupler of the present invention and the AUV; in the figure, 1 is the arc-shaped transmitting coil 1, 2 is the arc-shaped transmitting coil 2, 3 is the arc-shaped transmitting coil 3, 4 is the cylindrical receiving coil, 5 is the ferrite core, and 6 is the AUV shell;

[0046] Figure 2 The magnetic field distribution diagram obtained by controlling the three arc-shaped transmitting coils with the excitation source. In the figure, B represents the magnetic field intensity.

[0047] Figure 3 The graph is a variation curve of the offset distance and the coupling coefficient of the segmented arc coupler in the case of axial offset in a specific embodiment; PAS represents the coupling coefficient between the arc-shaped transmitting coil and the cylindrical receiving coil, k PBS represents the coupling coefficient between the arc-shaped transmitting coil 2 and the cylindrical receiving coil, k PCS represents the coupling coefficient between the arc-shaped transmitting coil 3 and the cylindrical receiving coil, k PAPB represents the coupling coefficient between arc-shaped transmitting coil 1 and arc-shaped transmitting coil 2, k PAPC represents the coupling coefficient between arc-shaped transmitting coil 1 and arc-shaped transmitting coil 3, k PBPC represents the coupling coefficient between the arc transmitting coil 2 and the arc transmitting coil 3;

[0048] Figure 4 is a curve diagram showing the relationship between the rotation angle and the coupling coefficient of the segmented arc coupler when the rotation angle is offset in a specific embodiment;

[0049] Figure 5 This is a topological diagram of the AUV three-phase wireless charging circuit adapted to the segmented arc coupler of the present invention; LFA The compensation inductor LFA The current, i LFB The compensation inductor L FB The current, i LFC The compensation inductor L FC The current, i LPA is the current flowing through the arc-shaped transmitting coil L PA The current, i LPB is the current flowing through the arc-shaped transmitting coil L PB The current, i LPC is the current flowing through the arc-shaped transmitting coil L PC Current, M PAS For the arc-shaped transmitting coil L PA With cylindrical receiving coil L S Mutual inductance between PBS For the arc-shaped transmitting coil L PB With cylindrical receiving coil L S Mutual inductance between PCS For the arc-shaped transmitting coil L PC With cylindrical receiving coil L S The mutual inductance between S is the current flowing through the cylindrical receiving coil L S The current, i L1 The compensation inductor L flows through the receiver S1 Current, V BAT Indicates the charging voltage of the charging system to the power battery pack, I BAT Indicates the charging current of the power battery pack by the charging system of the present invention;

[0050] Figure 6 This is the compensation parameter design flow chart of the AUV three-phase wireless charging system;

[0051] Figure 7 3 is a graph showing the change in rotation angle and output power of the AUV three-phase wireless charging system provided in a specific embodiment when the cylindrical receiving coil is rotated at different angles. DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0053] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0055] Specific implementation method 1. Combination Figure 1 and Figure 5 As shown, the present invention provides an AUV three-phase wireless charging system based on a segmented arc coupler, including a segmented arc coupler; the segmented arc coupler includes three identical arc-shaped transmitting coils and a cylindrical receiving coil,

[0056] The three arc-shaped transmitting coils are evenly distributed on the periphery of the circumference of the cylindrical receiving coil; the three arc-shaped transmitting coils are arranged on the outer surface of the AUV hull, and the cylindrical receiving coil is arranged on the inner surface of the AUV hull;

[0057] The excitation currents of the three arc-shaped transmitting coils are controlled separately by an excitation source; the three arc-shaped transmitting coils are arc-shaped transmitting coil one, arc-shaped transmitting coil two and arc-shaped transmitting coil three; the modulation method for forming a uniform magnetic field is as follows: the excitation current amplitudes of arc-shaped transmitting coil one and arc-shaped transmitting coil two change according to the cosine and sine laws respectively, and the excitation current amplitude of arc-shaped transmitting coil three remains unchanged; the excitation current phase difference between arc-shaped transmitting coil one and arc-shaped transmitting coil two and arc-shaped transmitting coil three is 90° respectively, and the amplitude and phase of arc-shaped transmitting coil one and arc-shaped transmitting coil two change with time, forming a uniform three-dimensional rotating magnetic field inside the AUV hull. In the synthesized three-dimensional rotating magnetic field, the synthesized magnetic field vector scans and covers any direction of a cylindrical area with time. Regardless of the angle offset of the receiving coil, there is always a part of the time when the magnetic field generated passes through the receiving coil, realizing omnidirectional wireless power transmission, thereby achieving the purpose of anti-rotational offset and suppressing output power fluctuations. The magnetic field distribution diagram formed under this modulation method is shown as follows Figure 2 As shown. Using the above modulation method, we can get Figure 3 and Figure 4 The test results are shown.

[0058] Specific embodiment 1: Combination Figure 3 Figure 2 shows how the coupling coefficient changes with offset distance when the coupling mechanism employs the magnetic field modulation method of the present invention, with axial offsets of 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm. The coupling coefficient curve changes relatively smoothly when axial offset occurs, minimizing the impact on the system. This demonstrates that the coupling mechanism provided by the present invention has strong resistance to axial offset.

[0059] Specific embodiment 2: Combination Figure 4Figure 2 shows how the coupling coefficient changes with rotation angle when the coupling mechanism employs the magnetic field modulation method of the present invention at angular offsets of 0°, 2°, 4°, 6°, 8°, 10°, and 12°. The coupling coefficient changes very little with the rotational offset angle, demonstrating that the coupling mechanism provided by the present invention has strong resistance to rotational offset.

[0060] The three arc-shaped transmitting coils have the same size and volume. The circumference formed by the three identical arc-shaped transmitting coils coincides with the center of the cylindrical receiving coil.

[0061] In this embodiment, the excitation currents of the three transmitting coils in the segmented arc coupler are independently controlled. These coils are driven by three independent half-bridge inverters in a three-phase voltage-source inverter using a phase-shift modulation strategy to regulate the excitation currents. Compared to existing approaches that rely on adding a DC-DC converter, this approach does not require additional circuitry. When the phase shift angle is 180°, the effective value of the three-phase inverter's output voltage reaches its maximum.

[0062] Further, combined Figure 1 and Figure 5 As shown, in order to adapt to the segmented arc coupler provided in this embodiment, an AUV three-phase wireless charging topology is provided. In this case, the charging system includes a power transmitter and a power receiver. The power transmitter includes a DC voltage source, a three-phase voltage inverter, a transmitter compensation network, and three-segment arc-shaped transmitting coils; the power receiver includes a cylindrical receiving coil, a receiver compensation network, a rectifier, an output capacitor, and a power battery pack.

[0063] The positive electrode and negative electrode of the DC voltage source are respectively connected to the positive electrode connection terminal and the negative electrode connection terminal of the three-phase voltage type inverter;

[0064] The transmitter compensation network is a three-phase compensation network. Each phase of the compensation network includes a transmitting compensation inductor, a transmitting compensation capacitor 1, and a transmitting compensation capacitor 2. The three single-phase AC output terminals of the three-phase voltage-type inverter are respectively connected to one end of the transmitting compensation inductor of each phase compensation network. The other end of the transmitting compensation inductor is simultaneously connected to the positive electrodes of transmitting compensation capacitor 1 and transmitting compensation capacitor 2. The negative electrode of each transmitting compensation capacitor 2 is correspondingly connected to the same-name end of a segment of an arc-shaped transmitting coil. The negative electrode of each transmitting compensation capacitor 1 and the opposite-name end of each segment of the arc-shaped transmitting coil are simultaneously connected to the negative connection terminal of the three-phase voltage-type inverter.

[0065] The cylindrical receiving coil is connected to the rectifier through the receiver compensation network. The DC power output by the rectifier is transferred to the power battery pack through the output capacitor for storage.

[0066] Going further, the circuit structure of the power transmitter is:

[0067] The three arc-shaped transmitting coils are arc-shaped transmitting coils L PA , arc-shaped transmitting coil L PB and arc-shaped transmitting coil L PC ;

[0068] The three-phase voltage-type inverter includes an A-phase inverter bridge, a B-phase inverter bridge, and a C-phase inverter bridge. The A-phase inverter bridge includes a switch tube S1, an anti-parallel freewheeling diode D1 of the switch tube S1, a switch tube S2, and an anti-parallel freewheeling diode D2 of the switch tube S2; the B-phase inverter bridge includes a switch tube S3, an anti-parallel freewheeling diode D3 of the switch tube S3, a switch tube S4, and an anti-parallel freewheeling diode D4 of the switch tube S4; the C-phase inverter bridge includes a switch tube S5, an anti-parallel freewheeling diode D5 of the switch tube S5, a switch tube S6, and an anti-parallel freewheeling diode D6 of the switch tube S6;

[0069] The drains of the upper arm switch tubes S1, S3 and S5 of each phase inverter bridge are connected to each other as the positive connection terminal and the DC voltage source V DC The positive electrode of the inverter bridge is connected, and the sources of the lower arm switch tubes S2, S4 and S6 of each phase are connected to each other as the negative electrode connection terminal and the DC voltage source V DC The source of the switch tube S1 is connected to the drain of the switch tube S2, and the connection point A is used as the output terminal of the A-phase AC power; the source of the switch tube S3 is connected to the drain of the switch tube S4, and the connection point B is used as the output terminal of the B-phase AC power; the source of the switch tube S5 is connected to the drain of the switch tube S6, and the connection point C is used as the output terminal of the C-phase AC power;

[0070] The A-phase compensation network of the transmitter compensation network includes the transmitter compensation inductor L FA , Transmitter compensation capacitor - C FA and the emission compensation capacitor C PA ;B phase compensation network includes transmitter compensation inductor L FB , Transmitter compensation capacitor - C FB and the emission compensation capacitor C PB ; The C-phase compensation network includes the transmitter compensation inductor L FC , Transmitter compensation capacitor - C FC and the emission compensation capacitor C PC ; The A-phase AC output terminal is connected to the transmitter compensation inductor L FA One end of the transmitter compensation inductor L FA The other end is connected to the transmitter compensation capacitor C FA and the emission compensation capacitor C PA The positive pole of the emission compensation capacitor is C PA The negative pole of the arc-shaped transmitting coil L is connected PA The same-name end, the transmitter compensation capacitor C FAThe negative pole and arc-shaped transmitting coil L PA The opposite end of the three-phase voltage inverter is connected to the negative terminal at the same time; the B-phase AC output terminal is connected to the transmitter compensation inductor L FB One end of the transmitter compensation inductor L FB The other end is connected to the transmitter compensation capacitor C FB and the emission compensation capacitor C PB The positive pole of the emission compensation capacitor is C PB The negative pole of the arc-shaped transmitting coil L is connected PB The same-name end, the transmitter compensation capacitor C FB The negative pole and arc-shaped transmitting coil L PB The opposite end of the three-phase voltage inverter is connected to the negative terminal at the same time; the C-phase AC output terminal is connected to the transmitter compensation inductor L FC One end of the transmitter compensation inductor L FC The other end is connected to the transmitter compensation capacitor C FC and the emission compensation capacitor C PC The positive pole of the emission compensation capacitor is C PC The negative pole of the arc-shaped transmitting coil L is connected PC The same-name end, the transmitter compensation capacitor C FC The negative pole and arc-shaped transmitting coil L PC The opposite-name ends of the three-phase voltage-type inverter are connected to the negative terminal of the three-phase voltage-type inverter at the same time.

[0071] The circuit structure of the power receiving end is:

[0072] The receiver compensation network includes the receiver compensation capacitor C S1 , receiver compensation capacitor C S2 , receiver compensation inductor L S1 and relay Q; the rectifier includes switch tube S7, switch tube S8, diode D7 and diode D8;

[0073] The drain of the switch tube S7 is connected to the cathode of the diode D7, the source of the switch tube S7 is connected to the drain of the switch tube S8, the source of the switch tube S8 is connected to the anode of the diode D8, and the cathode of the diode D8 is connected to the anode of the diode D7; the anode of the diode D7 serves as the positive input terminal of the rectifier, and the drain of the switch tube S8 serves as the negative input terminal of the rectifier;

[0074] Cylindrical receiving coil L S The same-name end of the receiver is connected to the compensation capacitor C S1 The positive pole of the receiver compensation capacitor C S1 The negative pole of the receiver is connected to the compensation inductor L S1 One end of the receiver compensation inductor L S1 The other end is connected to the positive input terminal of the rectifier through the relay Q; the receiver compensation capacitor CS1 The negative pole of the receiver is connected to the compensation capacitor C S2 The positive pole of the receiver compensation capacitor C S2 The negative pole is connected to the negative input terminal of the rectifier; the cylindrical receiving coil L S The opposite end of the diode D7 is connected to the source of the switch tube S8; the output capacitor C is connected between the cathode of the diode D7 and the anode of the diode D8. O , power battery pack and output capacitor C O in parallel.

[0075] The relay Q is composed of two power switch tubes connected in reverse series.

[0076] Going further, combined Figure 5 and Figure 6 As shown, in order to facilitate the analysis of the working principle of the system, the system's A phase circuit is taken as an example for analysis, and the inductance values ​​of the three arc-shaped transmitting coils are set to be equal, all L P ; Three arc-shaped transmitting coils and cylindrical receiving coil L S The mutual inductance of the three transmitter compensation inductors is equal, all are M; the inductance values ​​of the three transmitter compensation inductors are equal, all are L F The capacitance values ​​of the three transmitter compensation capacitors are equal, all C F The capacitance values ​​of the three transmitter compensation capacitors are equal, all C P ;U A is the effective value of the output voltage of the A-phase inverter bridge; R EQ is the equivalent input AC resistance of the rectifier;

[0077] In the constant current charging mode, the A phase compensation network of the AUV underwater charging system and the receiver compensation network are equivalent to a bilateral LCC compensation topology, and the current flowing through the receiver compensation inductor L S1 The current i L1 Expressed as:

[0078]

[0079] Where ω is the system operating angular frequency;

[0080] Under the condition that the mutual inductance between the transmitting coil and the receiving coil, the transmitting compensation inductance and the receiving compensation inductance are known, the bilateral LCC compensation network can achieve a constant current output that is independent of the load. In this mode, the output power P of the charging system is out-CC for:

[0081]

[0082] Furthermore, in the constant voltage charging mode, the A-phase compensation network of the AUV underwater charging system and the receiver compensation network are equivalent to the LCC-S compensation topology, and the output voltage U2 of the charging system is expressed as:

[0083]

[0084] Under the conditions that the mutual inductance between the transmitting coil and the receiving coil and the effective value of the output voltage of phase A of the inverter bridge are known, the LCC-S compensation topology can achieve a constant voltage output that is independent of the load.

[0085] In this mode, the output power of the charging system P out-CV for:

[0086]

[0087] According to the principle that the battery charging voltage does not change suddenly during the transient process of switching from constant current charging mode to constant voltage charging mode, the smooth switching condition of the charging system from constant current charging mode to constant voltage charging mode can be obtained as follows:

[0088]

[0089] Where R BAT is the resistance of the power battery pack.

[0090] Therefore, from formula (5), we can see that in the compensation parameter design process, as long as the receiving compensation inductor L is reasonably designed S1 By adjusting the inductance value, a smooth transition from constant current mode to constant voltage mode can be achieved.

[0091] This implementation relies on only one relay and a small number of compensation components, and can achieve a smooth transition between constant current charging mode and constant voltage charging mode through reasonable parameter design; the receiver uses only a single cylindrical coil, which not only helps to reduce the weight of the AUV but also realizes omnidirectional wireless power transmission, thereby achieving higher power transmission efficiency.

[0092] Figure 6 This is the compensation parameter design process of the system. The given parameters are as follows: system operating frequency f S , DC input voltage V DC , charging voltage V BAT , charging current I BAT and coupler parameters. Under the condition that the above parameters are known, the receiver compensation inductance L can be calculated using formula (5): S1 The inductance value is designed.

[0093] According to formula (6), the receiver compensation capacitor C S1 and receiver compensation capacitor C S2 The capacitance value is designed as follows:

[0094]

[0095] According to formula (7), the transmitter compensation capacitor C FA , Transmitter compensation capacitor - C FB , Transmitter compensation capacitor - C FC , Transmitter compensation capacitor C PA , Transmitter compensation capacitor C PB and the emission compensation capacitor C PC The capacitance value of the three emission compensation capacitors is C F The capacitance values ​​of the three emission compensation capacitors are C P , the calculation method is as follows:

[0096]

[0097] Among them C S For intermediate variables:

[0098]

[0099] Specific embodiment 3: In order to verify the effectiveness of the present invention, a simulation model was built by software for verification and analysis. The parameters selected for the simulation are shown in Table 1.

[0100] Table 1 Simulation parameters

[0101]

[0102] Under rated power conditions, when the cylindrical receiving coil rotates one circle, the simulation test results of the rotation angle change with the system output power are as follows: Figure 7 During one rotation, the output power fluctuation of the system is only 5.9%, which preliminarily proves that the coupling mechanism provided by this embodiment has good anti-rotational deviation capability.

[0103] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. A three-phase wireless charging system for AUV based on segmented arc coupler, characterized by It includes a segmented arc coupler; the segmented arc coupler includes three identical arc-shaped transmitting coils and a cylindrical receiving coil, The three arc-shaped transmitting coils are evenly distributed around the circumference of the cylindrical receiving coil; Three arc-shaped transmitting coils are set on the outer surface of the AUV hull, and a cylindrical receiving coil is set on the inner surface of the AUV hull; The excitation currents of the three arc-shaped transmitting coils are controlled separately by an excitation source; the three arc-shaped transmitting coils are arc-shaped transmitting coil 1, arc-shaped transmitting coil 2, and arc-shaped transmitting coil 3, so that the excitation current amplitudes of arc-shaped transmitting coil 1 and arc-shaped transmitting coil 2 change according to the cosine and sine laws respectively, while the excitation current amplitude of arc-shaped transmitting coil 3 remains unchanged; The phase difference between the excitation currents of the arc-shaped transmitting coil 1, the arc-shaped transmitting coil 2 and the arc-shaped transmitting coil 3 is 90°, forming a uniform spatial rotating magnetic field inside the AUV hull.

2. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 1 is characterized in that: The three arc-shaped transmitting coils are driven by three independent half-bridge inverter bridges in a three-phase voltage-type inverter using a phase-shift modulation strategy.

3. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 2 is characterized in that: The charging system includes an electric energy transmitting end and an electric energy receiving end. The electric energy transmitting end includes a DC voltage source, a three-phase voltage type inverter, a transmitter compensation network and three arc-shaped transmitting coils; the electric energy receiving end includes a cylindrical receiving coil, a receiver compensation network, a rectifier, an output capacitor and a power battery pack. The positive electrode and negative electrode of the DC voltage source are respectively connected to the positive electrode connection terminal and the negative electrode connection terminal of the three-phase voltage type inverter; The transmitter compensation network is a three-phase compensation network. Each phase of the compensation network includes a transmitting compensation inductor, a transmitting compensation capacitor 1, and a transmitting compensation capacitor 2. The three single-phase AC output terminals of the three-phase voltage-type inverter are respectively connected to one end of the transmitting compensation inductor of each phase compensation network. The other end of the transmitting compensation inductor is simultaneously connected to the positive electrodes of transmitting compensation capacitor 1 and transmitting compensation capacitor 2. The negative electrode of each transmitting compensation capacitor 2 is correspondingly connected to the same-name end of a segment of an arc-shaped transmitting coil. The negative electrode of each transmitting compensation capacitor 1 and the opposite-name end of each segment of the arc-shaped transmitting coil are simultaneously connected to the negative connection terminal of the three-phase voltage-type inverter. The cylindrical receiving coil is connected to the rectifier through the receiver compensation network. The DC power output by the rectifier is transferred to the power battery pack through the output capacitor for storage.

4. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 3 is characterized in that: The circuit structure of the power transmitter is: The three arc-shaped transmitting coils are arc-shaped transmitting coils L PA , arc-shaped transmitting coil L PB and arc-shaped transmitting coil L PC ; The three-phase voltage-type inverter includes an A-phase inverter bridge, a B-phase inverter bridge, and a C-phase inverter bridge. The A-phase inverter bridge includes a switch tube S1, an anti-parallel freewheeling diode D1 of the switch tube S1, a switch tube S2, and an anti-parallel freewheeling diode D2 of the switch tube S2; the B-phase inverter bridge includes a switch tube S3, an anti-parallel freewheeling diode D3 of the switch tube S3, a switch tube S4, and an anti-parallel freewheeling diode D4 of the switch tube S4; the C-phase inverter bridge includes a switch tube S5, an anti-parallel freewheeling diode D5 of the switch tube S5, a switch tube S6, and an anti-parallel freewheeling diode D6 of the switch tube S6; The drains of the switch tubes S1, S3 and S5 are connected to each other as positive terminals and connected to the DC voltage source V DC The positive electrode of the switch tube S2, the switch tube S4 and the switch tube S6 are connected to each other as the negative electrode connection terminal and the DC voltage source V DC The source of the switch tube S1 is connected to the drain of the switch tube S2, and the connection point A is used as the output terminal of the A-phase AC power; the source of the switch tube S3 is connected to the drain of the switch tube S4, and the connection point B is used as the output terminal of the B-phase AC power; the source of the switch tube S5 is connected to the drain of the switch tube S6, and the connection point C is used as the output terminal of the C-phase AC power; The A-phase compensation network of the transmitter compensation network includes the transmitter compensation inductor L FA , Transmitter compensation capacitor - C FA and the emission compensation capacitor C PA ;B phase compensation network includes transmitter compensation inductor L FB , Transmitter compensation capacitor - C FB and the emission compensation capacitor C PB ; The C-phase compensation network includes the transmitter compensation inductor L FC , Transmitter compensation capacitor - C FC and the emission compensation capacitor C PC ; The A-phase AC output terminal is connected to the transmitter compensation inductor L FA One end of the transmitter compensation inductor L FA The other end is connected to the transmitter compensation capacitor C FA and the emission compensation capacitor C PA The positive pole of the emission compensation capacitor is C PA The negative pole of the arc-shaped transmitting coil L is connected PA The same-name end, the transmitter compensation capacitor C FA The negative pole and arc-shaped transmitting coil L PA The opposite end of the three-phase voltage inverter is connected to the negative terminal at the same time; the B-phase AC output terminal is connected to the transmitter compensation inductor L FB One end of the transmitter compensation inductor L FB The other end is connected to the transmitter compensation capacitor C FB and the emission compensation capacitor C PB The positive pole of the emission compensation capacitor is C PB The negative pole of the arc-shaped transmitting coil L is connected PB The same-name end, the transmitter compensation capacitor C FB The negative pole and arc-shaped transmitting coil L PB The opposite end of the three-phase voltage inverter is connected to the negative terminal at the same time; the C-phase AC output terminal is connected to the transmitter compensation inductor L FC One end of the transmitter compensation inductor L FC The other end is connected to the transmitter compensation capacitor C FC and the emission compensation capacitor C PC The positive pole of the emission compensation capacitor is C PC The negative pole of the arc-shaped transmitting coil L is connected PC The same-name end, the transmitter compensation capacitor C FC The negative pole and arc-shaped transmitting coil L PC The opposite-name ends of the three-phase voltage-type inverter are connected to the negative terminal of the three-phase voltage-type inverter at the same time.

5. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 4 is characterized in that: The circuit structure of the power receiving end is: The receiver compensation network includes the receiver compensation capacitor C S1 , receiver compensation capacitor C S2 , receiver compensation inductor L S1 and relay Q; the rectifier includes switch tube S7, switch tube S8, diode D7 and diode D8; The drain of the switch tube S7 is connected to the cathode of the diode D7, the source of the switch tube S7 is connected to the drain of the switch tube S8, the source of the switch tube S8 is connected to the anode of the diode D8, and the cathode of the diode D8 is connected to the anode of the diode D7; the anode of the diode D7 serves as the positive input terminal of the rectifier, and the drain of the switch tube S8 serves as the negative input terminal of the rectifier; Cylindrical receiving coil L S The same-name end of the receiver is connected to the compensation capacitor C S1 The positive pole of the receiver compensation capacitor C S1 The negative pole of the receiver is connected to the compensation inductor L S1 One end of the receiver compensation inductor L S1 The other end is connected to the positive input terminal of the rectifier through the relay Q; the receiver compensation capacitor C S1 The negative pole of the receiver is connected to the compensation capacitor C S2 The positive pole of the receiver compensation capacitor C S2 The negative pole is connected to the negative input terminal of the rectifier; the cylindrical receiving coil L S The opposite end is connected to the source of the switch tube S8; The output capacitor C is connected between the cathode of diode D7 and the anode of diode D8. O , power battery pack and output capacitor C O in parallel.

6. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 5, characterized in that: Set the inductance of the three arc-shaped transmitting coils to be equal, all L P ; Three arc-shaped transmitting coils and cylindrical receiving coil L S The mutual inductance is equal, both are M; The inductance values ​​of the three transmitter compensation inductors are equal, all L F The capacitance values ​​of the three transmitter compensation capacitors are equal, all C F The capacitance values ​​of the three transmitter compensation capacitors are equal, all C P ;U A is the effective value of the output voltage of the A-phase inverter bridge; R EQ is the equivalent input AC resistance of the rectifier; In the constant current charging mode, the A-phase compensation network and the receiver compensation network are equivalent to a bilateral LCC compensation topology, and the current flowing through the receiver compensation inductor L S1 The current i L1 Expressed as: Where ω is the system operating angular frequency; The output power P of the charging system out-CC for:

7. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 6, characterized in that: In constant voltage charging mode, the A-phase compensation network and the receiver compensation network are equivalent to the LCC-S compensation topology, and the output voltage U2 of the charging system is expressed as: Output power P of the charging system out-CV for:

8. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 7, characterized in that: The smooth switching condition of the charging system from the constant current charging mode to the constant voltage charging mode is: Where R BAT is the resistance of the power battery pack.

9. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 8, characterized in that: Receiver compensation capacitor C S1 and receiver compensation capacitor C S2 The capacitance value is determined by the following formula:

10. The AUV three-phase wireless charging system based on segmented arc coupler according to claim 9, characterized in that: The capacitance value of one of the three transmitter compensation capacitors C F And the capacitance value of the three transmitter compensation capacitors C P Determined according to the following formula: Among them C S For intermediate variables:

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