Capsule type variable structure magnetic coupling mechanism and application thereof

Abstract

The invention belongs to the technical field of underwater wireless power transmission, and particularly relates to a capsule type variable structure magnetic coupling mechanism and application thereof. According to the capsule type variable structure magnetic coupling mechanism designed by the invention, the distance between the transmitting side magnetic coupling mechanism and the receiving side magnetic coupling mechanism is reduced by adjusting the size of the receiving side, so that the magnetic coupling coefficient is increased, the path of a high-frequency electromagnetic field in seawater is reduced, and the power and efficiency of underwater wireless power transmission can be improved. According to the underwater charging station, an additional clamping device is not needed on the charging base, axial fixing is achieved after the bag-shaped structure is filled with water, a method that the distance between the receiving side and the transmitting side is judged through self-inductance of the receiving side is adopted, an additional distance measuring device is not needed, a self-inductance measuring device of the receiving side is integrated in the underwater vehicle, and the underwater charging station has the advantages of being high in reliability and high in reliability. And the distance judgment is accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater wireless power transmission, and in particular relates to a capsule-type variable structure magnetic coupling mechanism and application thereof. Background Art

[0002] With the increasing demand for ocean development, protection and defense, various underwater submersibles have been developed. However, underwater submersibles are currently mainly powered by batteries, and their power supply has become a key issue that limits the long-term operation of underwater submersibles. Underwater wireless power transmission technology, as a new power transmission method, does not require physical plugging and unplugging, and has the characteristics of high reliability, practicality and safety, which is expected to solve the power supply problem of underwater submersibles.

[0003] The patent "Loosely coupled transformer and underwater wireless power transmission system using the transformer [ZL202011390960.5]" proposes a new loosely coupled transformer structure. The transmitting coil and receiving coil of the loosely coupled transformer adopt a modular design and a symmetrical magnetic circuit design. They have strong axis rotation and axial anti-deviability, and low requirements for the docking accuracy of the coupling mechanism. However, when the diameter of the underwater submersible is close to the diameter of the transmitting coil, the wireless charging efficiency and charging power are both large, and when the diameter of the underwater submersible is much smaller than the diameter of the transmitting coil, the wireless charging efficiency and charging power will drop significantly. Moreover, the underwater charging station composed of the magnetic coupling mechanism requires a special clamping device, which increases the difficulty of system control and reduces the reliability of the charging station.

[0004] When the diameter of the underwater vehicle is much smaller than the diameter of the transmitting coil, the mutual inductance of the magnetic coupling mechanism is greatly reduced, and the path of the electromagnetic field in the seawater increases. These factors will lead to a significant decrease in the wireless charging efficiency and charging power. Therefore, there is a need for a magnetic coupling mechanism that has both strong anti-drift capability and can maintain a large mutual inductance value when the diameter of the underwater vehicle is much smaller than the diameter of the transmitting coil. The transmitting coil of a general underwater charging base station is fixed and difficult to replace and maintain, and is generally designed to be larger to facilitate docking with underwater vehicles of different sizes. At present, there are no reports of magnetic coupling mechanisms that have both strong anti-drift performance and strong adaptability to underwater vehicle sizes. Summary of the invention

[0005] The purpose of the present invention is to provide a capsule-type variable structure magnetic coupling mechanism and its application in view of the problems of weak adaptability to underwater vehicle size and weak anti-deviation performance in the underwater wireless power transmission system currently used for underwater vehicles. The present invention changes the size of the receiving end through an expandable receiving end, improves the coupling coefficient between the transmitting coil and the receiving coil, reduces the path of the electromagnetic field in the seawater, and can effectively improve the power and efficiency of energy transmission. In addition, the proposed magnetic coupling mechanism adopts a symmetrical magnetic circuit design, so that the entire structure has a strong anti-deviation performance.

[0006] A capsule-type variable structure magnetic coupling mechanism comprises a transmitting side magnetic coupling mechanism and a receiving side magnetic coupling mechanism; the receiving side magnetic coupling mechanism comprises a capsule-type structure, the capsule-type structure is equipped with a water pump, columnar magnetic core windings are evenly arranged in the circumferential direction outside the capsule-type structure, the wires wound outside each columnar magnetic core winding are connected in series, and the capsule-type structure is adapted to the transmitting side magnetic coupling mechanism after being filled with water and bulged.

[0007] Furthermore, the transmitting-side magnetic coupling mechanism is a fixed structure formed by a plurality of groups of columnar magnetic core winding units connected in series, and the columnar magnetic core winding unit includes an upper magnetic core, a lower magnetic core, and a columnar magnetic core winding connecting the upper magnetic core and the lower magnetic core.

[0008] Furthermore, in the transmitting-side magnetic coupling mechanism, multiple groups of upper magnetic cores are connected end to end to form a ring-shaped or polygonal closed loop, and the closed loop formed by the lower magnetic cores is the same as that of the upper magnetic cores.

[0009] Furthermore, the cylindrical magnetic core in the cylindrical magnetic core winding is in the shape of a cylinder or a rectangular parallelepiped.

[0010] An application of a capsule-type variable structure magnetic coupling mechanism is used for underwater wireless power transmission. The transmitting side magnetic coupling mechanism is installed in the underwater charging station, and a variety of different receiving side magnetic coupling mechanisms are installed in each submersible. The size of the capsule structure before filling with water is adapted to the submersible. The underwater wireless charging station using this structure can achieve charging without a special clamping device, which will reduce the difficulty of charging station control, improve the reliability of the charging station, and reduce maintenance costs.

[0011] Furthermore, the underwater charging station comprises a trumpet-shaped submersible capture device, a charging chamber and a charging base; the charging chamber is mounted on the charging base, the trumpet-shaped submersible capture device is mounted at one end of the charging chamber, a groove is provided on the inner wall surface of the middle part of the charging chamber, and the transmitting side magnetic coupling mechanism is embedded in the groove after being water-filled and structure-changed;

[0012] After the submersible enters the charging chamber from the trumpet-shaped submersible capture device, the sac-shaped structure of the receiving-side magnetic coupling mechanism expands after being filled with water, causing the receiving-side magnetic coupling mechanism to be stuck into the groove, thereby limiting the axial movement of the submersible during the charging process in the groove.

[0013] Furthermore, a receiving-side self-inductance measuring device is mounted inside the submersible. After the submersible enters the charging chamber from the trumpet-shaped submersible capture device, during the process in which the sac-type structure of the receiving-side magnetic coupling mechanism is filled with water and expands, the receiving-side self-inductance measuring device applies an AC current signal to the receiving-side magnetic coupling mechanism, and calculates the self-inductance value L of the receiving-side magnetic coupling mechanism according to the amplitude I and frequency ω of the AC current signal and the voltage U across the two ends of the receiving-side magnetic coupling mechanism.

[0014] When the self-inductance value L of the magnetic coupling mechanism on the receiving side is greater than a preset threshold, it is determined that the mutual inductance requirement for charging is met, the bladder-type structure stops filling with water, and the submersible starts charging at the underwater charging station.

[0015] The beneficial effects of the present invention are:

[0016] The capsule-type variable structure magnetic coupling mechanism designed by the present invention reduces the distance between the transmitting side magnetic coupling mechanism and the receiving side magnetic coupling mechanism by adjusting the receiving side size, thereby increasing the magnetic coupling coefficient, reducing the path of the high-frequency electromagnetic field in the seawater, and improving the power and efficiency of underwater wireless power transmission. When the underwater charging station of the present invention is applied, no additional clamping device is required on the charging base, and axial fixation is achieved after the capsule-type structure is filled with water. The method of using the receiving side self-inductance to judge the distance between the receiving side and the transmitting side does not require an additional distance measuring device. The receiving side self-inductance measuring device is integrated inside the submersible, which has the advantages of high reliability and accurate distance judgment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the capsule-type variable structure magnetic coupling mechanism in the present invention, wherein (a) is the transmitting side magnetic coupling mechanism, and (b) is the receiving side magnetic coupling mechanism.

[0018] Figure 2 Schematic diagram of a cylindrical core winding.

[0019] Figure 3 It is a working flow chart of the capsule-type variable structure magnetic coupling mechanism in the present invention.

[0020] Figure 4 Comparison of the capsule-type variable structure magnetic coupling mechanism before and after water filling. (a) is the annular capsule structure after water filling; (b) is the annular capsule structure before water filling.

[0021] Figure 5 It is a schematic diagram of the capsule-type variable structure magnetic coupling mechanism in the present invention applied to an underwater charging station.

[0022] Figure 6 Schematic diagram of the capsule-type variable structure magnetic coupling mechanism after water injection and expansion. (a) is a top view; (b) is an axial view.

[0023] Figure numerals: 1_1 cylindrical magnetic core winding, 1_2 annular rubber bag, 1_3 cylindrical magnetic core, 1_4 pipeline, 1_5 water pump; 2_1 winding, 2_2 cylindrical magnetic core, 5_1 submersible capture device, 5_2 submersible and receiving coil, 5_3 base of charging base station, 5_4 transmitting coil of charging base station, 5_5 transmitting part power converter device of charging base station, 5_6 charging cabin, 6_1 cylindrical magnetic core of transmitting side magnetic coupling mechanism, 6_2 cylindrical magnetic core winding of transmitting side magnetic coupling mechanism, 6_3 cylindrical magnetic core winding of receiving side magnetic coupling mechanism. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings.

[0025] The present invention provides a capsule-type variable structure magnetic coupling mechanism such as Figure 1 As shown, it includes a transmitting side magnetic coupling mechanism and a receiving side magnetic coupling mechanism. The transmitting side magnetic coupling mechanism is a cage-type magnetic coupling mechanism composed of a columnar magnetic core and a columnar magnetic core winding. The receiving side magnetic coupling mechanism includes a columnar magnetic core winding, a capsule-type structure and a water pump. A plurality of columnar magnetic core windings are connected in series and evenly distributed on the periphery of the capsule-type structure. The water pump can inject or suck out seawater into the capsule-type structure, resulting in a size change of the capsule-type structure. When seawater is injected, the diameter of the capsule-type structure becomes larger, and when seawater is sucked out, the diameter of the capsule-type structure becomes smaller. The variable structure is achieved by injecting and sucking out seawater into the capsule-type structure.

[0026] The basic components of the magnetic coupling mechanism are cylindrical magnetic core windings such as Figure 2 As shown, a wire is wound around the cylindrical magnetic core to form a coil, and the magnetic core and the coil together form a cylindrical magnetic core winding. The cylindrical magnetic core can be cylindrical, rectangular or other cylindrical magnetic cores, which are used to constrain the magnetic field generated by the coil and provide a magnetic path for the magnetic field.

[0027] The working steps of the capsule variable structure magnetic coupling mechanism are as follows: Figure 3 As shown, the first step is to detect whether the underwater submersible has completed the docking with the underwater charging base station; the second step is to start the water pump to inject seawater into the capsule structure after the docking is completed, and the diameter of the capsule structure becomes larger, so that the distance between the receiving side magnetic coupling mechanism installed on the submersible and the transmitting side magnetic coupling mechanism on the charging base station becomes closer; the third step is to measure the self-inductance of the receiving coil. As the distance between the receiving coil and the transmitting coil continues to decrease, the self-inductance of the receiving coil continues to increase. When the self-inductance of the receiving coil is greater than the set value, it can be determined that the water injection is completed. The fourth step is to start wireless charging; the fifth step is to start the water pump after the charging is completed to suck out the seawater in the capsule structure, and the receiving side magnetic coupling mechanism installed on the submersible returns to a smaller size; the sixth step is for the underwater submersible to drive out of the charging base station, completing the entire charging process.

[0028] like Figure 4As shown, the diameter of the annular rubber bag becomes larger after water is injected, and the receiving side cylindrical magnetic core winding is installed on the periphery of the rubber bag. As the diameter of the rubber bag increases, the cylindrical magnetic core winding becomes closer to the transmitting side magnetic coupling mechanism. At this time, the magnetic coupling coefficient between the transmitting side and the receiving side becomes larger, and the path of the electromagnetic field in the seawater becomes smaller, thereby achieving high-power and high-efficiency wireless power transmission. After the charging is completed, the seawater in the rubber bag is discharged, the diameter of the rubber bag becomes smaller, and the underwater submersible returns to the size before charging, completing the charging process.

[0029] Through the above working process, it can be known that the capsule-type variable structure magnetic coupling mechanism provided by the present invention can adjust the distance between the receiving side magnetic coupling mechanism and the transmitting side magnetic coupling mechanism through variable structure, thereby achieving a larger magnetic coupling coefficient and reducing the path of the magnetic field in seawater, thereby realizing high-power and high-efficiency wireless power transmission.

[0030] Since the receiving side of the proposed magnetic coupling mechanism has the ability to change structure, the corresponding charging base station does not require an additional clamping device. The schematic diagram of the designed charging base station is shown in Figure 5 As shown, it includes a submersible capture device, a submersible and a receiving coil carried by it, a base of a charging base station, a transmitting coil of the charging base station, a transmitting part power converter device of the charging base station, a charging cabin, etc., wherein the magnetic coupling mechanism composed of the transmitting coil and the receiving coil on the submersible directly determines the charging power and charging efficiency of the wireless power transmission system. Unlike the traditional charging station, the charging station structure proposed by the present invention does not require a special clamping device, which not only reduces the difficulty of controlling the charging station, but also increases the system reliability and reduces the maintenance cost.

[0031] The method for achieving axial fixation of the charging station is as follows: Figure 5 As shown, the charging chamber has a groove, and the generating coil of the charging base station is embedded in the groove. After the underwater submersible enters the charging chamber and is filled with water, the receiving coil of the submersible expands due to the structure after the water injection, causing the receiving coil to be stuck in the groove. In this way, the axial movement distance of the submersible is limited in the groove during the entire charging process. The proposed magnetic coupling mechanism has strong anti-drift performance, including axial anti-drift and rotational anti-drift. Therefore, the charging base station solution can achieve high-efficiency charging without using a clamping device.

[0032] Figure 6 It is a loosely coupled transformer designed according to the above scheme. The transmitting side magnetic coupling mechanism is fixed on Figure 5 At the 5_4 portion of the trumpet-shaped capture device shown, the receiving-side magnetic coupling mechanism can be fixed on the outer periphery of the submersible. After water is injected, the diameter of the receiving-side magnetic coupling mechanism becomes larger, and after the diameter becomes larger, it is stuck in the groove of the charging chamber 5_6.

[0033] The transmitting coil of the loosely coupled transformer consists of a cylindrical core winding and the top and bottom cores, while the receiving end consists of only a cylindrical core winding. Figure 6 As shown, there is a certain distance between each magnetic core winding. The wires of the transmitting end and the receiving end magnetic core winding are connected in series respectively. The principle of wire connection is that the magnetic field direction of the cylindrical magnetic core winding is the same after the same loosely coupled transformer winding is energized.

[0034] In practical applications, the size of the transmitting and receiving windings of the loosely coupled transformer and the core and wire diameter of the columnar winding can be selected according to the size of the submersible and the transmission efficiency requirements to meet the needs of the submersible.

[0035] The present invention improves the adaptability of underwater wireless charging stations to the size of submersibles, and one charging station can charge submersibles of various diameters, with high charging power and efficiency. The present invention adopts modular and symmetrical magnetic circuit design and has strong anti-deviation capability.

[0036] Embodiment 1:

[0037] In this embodiment, the parameters of a loosely coupled transformer are designed as follows: the transmitting end and the receiving end transformer winding each have 12 columnar windings. The length, width and height of the columnar winding core are rectangular parallelepiped cores of 15mm, 5mm and 120mm respectively, and the number of turns of each core is 10 turns; the diameter of the transmitting coil is 340mm, the diameter of the submersible is 110mm, and the diameter of the receiving coil is adjustable. The diameter of the receiving coil before water injection is 180mm, and the diameter of the receiving coil after water injection is 300mm.

[0038] The annular rubber bag is filled with water. As the diameter of the annular rubber bag increases, the distance between the transmitting side magnetic coupling mechanism and the receiving side magnetic coupling mechanism decreases. The relationship between the distance and the self-inductance, mutual inductance and coupling coefficient is shown in Table 1. It can be seen that the closer the distance between the transmitting side magnetic coupling mechanism and the receiving side magnetic coupling mechanism is, the higher the coupling coefficient is. When the distance is 8mm, the coupling coefficient is 0.523, and the self-inductance of the receiving coil is 136.4498uH. When the distance is 80mm, the coupling coefficient is only 0.163, and the self-inductance of the receiving coil is 66.3957uH. In the process of the two coils approaching, the mutual inductance and the self-inductance of the receiving side both change significantly. Therefore, the distance between the receiving side coil and the transmitting side coil can be determined by measuring the self-inductance value of the receiving coil.

[0039] The method for measuring the self-inductance of the receiving coil is as follows: apply an AC current signal with an amplitude of 1A and a frequency of 20kHz to the receiving coil, and then measure the voltage across the receiving coil. According to the calculation method shown in formula (1), the self-inductance value of the receiving end can be determined. Experimental data show that the increase in the self-inductance value is positively correlated with the increase in the coupling coefficient. Therefore, by calculating and measuring the self-inductance value of the receiving end, it can be indirectly determined whether the water injection process has reached the predetermined standard. In order to achieve this goal, a corresponding circuit is designed at the receiving end, which can accurately measure and calculate the self-inductance value of the receiving end.

[0040]

[0041] Where L is the self-inductance of the receiving coil, ω is the frequency of the applied current signal, I is the amplitude of the applied current signal, and U is the voltage amplitude across the receiving coil.

[0042] Since the transformer is highly symmetrical, the inner ring is rotated every 15° for a total of 360°. The relationship between the collected rotation angle and the self-inductance, mutual inductance and coupling coefficient is shown in Table 2. It can be seen that when the rotation angle is in the range of 0° to 360°, the self-inductance and mutual inductance of the coil change little with the rotation angle, and the coupling coefficient remains above 0.44.

[0043] During the docking process between the submersible and the charging station, the axial distance may deviate. When the magnetic coupling mechanism on the transmitting side is completely aligned with the magnetic coupling mechanism on the receiving side, the axial offset is zero. The relationship between the offset distance and the change of self-inductance, mutual inductance and coupling coefficient is shown in Table 3.

[0044] During the structural change of the sac-like structure on the receiving side, it is necessary to measure the distance between the receiving side and the transmitting side in real time, which needs to meet both the mutual inductance requirements of charging and the axial fixation requirements. Underwater distance measurement requires the distance measuring device to be in contact with seawater, which has the problem of long-term operation reliability. The present invention proposes a method of using the self-inductance of the receiving side to judge the distance between the receiving side and the transmitting side. This method does not require an additional distance measuring device. The self-inductance measurement device on the receiving side is integrated inside the submersible, which has the advantages of high reliability and accurate distance judgment.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A capsule-type variable structure magnetic coupling mechanism, characterized in that: It includes a transmitting side magnetic coupling mechanism and a receiving side magnetic coupling mechanism; the receiving side magnetic coupling mechanism includes a capsule-type structure, the capsule-type structure is equipped with a water pump, columnar magnetic core windings are evenly arranged circumferentially outside the capsule-type structure, the wires wound outside each columnar magnetic core winding are connected in series, and the capsule-type structure is adapted to the transmitting side magnetic coupling mechanism after being filled with water and bulged.

2. The capsule-type variable structure magnetic coupling mechanism according to claim 1, characterized in that: The transmitting-side magnetic coupling mechanism is a fixed structure formed by a plurality of groups of columnar magnetic core winding units connected in series, wherein the columnar magnetic core winding unit comprises an upper magnetic core, a lower magnetic core and a columnar magnetic core winding connecting the upper magnetic core and the lower magnetic core.

3. The capsule-type variable structure magnetic coupling mechanism according to claim 2, characterized in that: In the transmitting-side magnetic coupling mechanism, multiple groups of upper magnetic cores are connected end to end to form a ring-shaped or polygonal closed loop, and the closed loop formed by the lower magnetic cores is the same as that of the upper magnetic cores.

4. The capsule-type variable structure magnetic coupling mechanism according to claim 3, characterized in that: The columnar magnetic core in the columnar magnetic core winding is in the shape of a cylinder or a cuboid.

5. An application of the capsule-type variable structure magnetic coupling mechanism according to claim 1, characterized in that: Used for underwater wireless power transmission, the transmitting-side magnetic coupling mechanism is installed in the underwater charging station, and a variety of different receiving-side magnetic coupling mechanisms are installed on each submersible respectively. The size of the bladder-type structure before being filled with water is adapted to the submersible.

6. The application of a capsule-type variable structure magnetic coupling mechanism according to claim 5, characterized in that: The underwater charging station comprises a trumpet-shaped underwater vehicle capture device, a charging chamber and a charging base; the charging chamber is mounted on the charging base, the trumpet-shaped underwater vehicle capture device is mounted at one end of the charging chamber, a groove is provided on the inner wall surface of the middle part of the charging chamber, and the transmitting side magnetic coupling mechanism is embedded in the groove after being water-filled and structure-changed; After the submersible enters the charging chamber from the trumpet-shaped submersible capture device, the sac-shaped structure of the receiving-side magnetic coupling mechanism expands after being filled with water, causing the receiving-side magnetic coupling mechanism to be stuck into the groove, thereby limiting the axial movement of the submersible during the charging process in the groove.

7. The application of a capsule-type variable structure magnetic coupling mechanism according to claim 5, characterized in that: The submersible is equipped with a receiving side self-inductance measuring device inside. After the submersible enters the charging chamber from the trumpet-shaped submersible capture device, during the process of the sac-type structure of the receiving side magnetic coupling mechanism being filled with water and expanding, the receiving side self-inductance measuring device applies an AC current signal to the receiving side magnetic coupling mechanism, and calculates the self-inductance value L of the receiving side magnetic coupling mechanism according to the amplitude I and frequency ω of the AC current signal and the voltage U across the two ends of the receiving side magnetic coupling mechanism. When the self-inductance value L of the magnetic coupling mechanism on the receiving side is greater than a preset threshold, it is determined that the mutual inductance requirement for charging is met, the bladder-type structure stops filling with water, and the submersible starts charging at the underwater charging station.

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