Wireless charging assembly

Abstract

The wireless charging assembly is applied to an electric vehicle, the electric vehicle comprises a vehicle body and a kickstand movably connected with the vehicle body, and the wireless charging assembly is characterized by further comprising a charging module and a receiving module; the charging module comprises a charging circuit and a transmitting coil; the receiving module comprises a receiving circuit and a receiving coil, and the receiving coil is arranged on the foot support; the charging circuit transmits electric energy to the receiving circuit through electromagnetic induction between the transmitting coil and the receiving coil. The electromagnetic induction distance between the transmitting coil and the receiving coil is smaller than 30 mm, and the size ratio of the transmitting coil to the receiving coil is 1.5-3. By optimizing the proportion of the transmitting coil and the receiving coil, higher energy transmission efficiency is achieved, when the size proportion of the transmitting coil and the receiving coil is within 1.5-3, mutual inductance is enhanced, and it can be guaranteed that the charging efficiency is 89% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless charging and relates to a wireless charging component. Background Art

[0002] Existing wireless charging technology is mainly used in portable smart devices such as mobile phones and photographic equipment. The power requirements of these devices are relatively low, so wireless charging technology can better meet their needs. However, when it comes to two-wheeled electric vehicles, the situation is quite different. The power requirements of two-wheeled electric vehicles are usually much higher than those of smartphones or photographic equipment, especially when high power output of more than 250W is required. In addition, in order to ensure the effective operation of electric vehicles and the safety of users, the wireless charging system must not only provide high power, but also maintain a high efficiency of at least 89% and control temperature rise to avoid the negative impact of overheating on battery performance and life. Summary of the invention

[0003] The present invention provides a wireless charging component, aiming to improve the charging efficiency by setting the ratio of a transmitting coil to a receiving coil and the distance between the transmitting coil and the receiving coil.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A wireless charging assembly is applied to an electric vehicle, the electric vehicle comprising a vehicle body and a kickstand movably connected to the vehicle body, characterized in that it also comprises a charging module and a receiving module;

[0006] The charging module includes a charging circuit and a transmitting coil;

[0007] The receiving module includes a receiving circuit and a receiving coil, and the receiving coil is arranged on the foot support;

[0008] The charging circuit transmits electric energy to the receiving circuit through electromagnetic induction between the transmitting coil and the receiving coil;

[0009] The electromagnetic induction distance between the transmitting coil and the receiving coil is less than 30 mm, and the size ratio of the transmitting coil to the receiving coil is 1.5-3.

[0010] Preferably, the size ratio of the transmitting coil and the receiving coil is a numerical ratio between their diameters, the diameter of the transmitting coil is 150 mm to 190 mm, and the diameter of the receiving coil is 70 mm to 90 mm.

[0011] Preferably, the transmitting coil is made of 4 mm wire, wound with 12 turns, and the winding method adopted is the Alpha winding method.

[0012] Preferably, the receiving coil is made of 2.5 mm wire, wound with 8 turns, and the winding method adopted is the Alpha winding method.

[0013] Preferably, the receiving coil is sleeved on the foot support, and the receiving coil includes a circular shape and an elliptical shape.

[0014] Preferably, the charging module further includes a magnetic isolation sheet and a plastic lower cover;

[0015] The transmitting coil, the magnetic isolation sheet and the plastic lower cover are stacked in sequence.

[0016] Preferably, the transmitting coil is fixed on the magnetic isolation sheet, and the magnetic isolation sheet is used to reduce the magnetic field range of the transmitting coil.

[0017] Preferably, the diameter of the circular receiving coil is 85 mm.

[0018] Preferably, the major semi-axis of the elliptical receiving coil is 90 mm, and the minor semi-axis is 70 mm.

[0019] Preferably, the shape of the magnetic isolation sheet matches the shape of the transmitting coil.

[0020] Beneficial effects of the present invention: The present application achieves higher energy transmission efficiency by optimizing the ratio of the transmitting coil and the receiving coil. When the size ratio of the transmitting coil and the receiving coil is within 1.5 to 3, the spacing between the transmitting coil and the receiving coil is less than 30 mm, and the mutual inductance is enhanced, which can ensure that the two-wheeled electric vehicle is at a higher charging efficiency, that is, more than 89%. When charging, the user only needs to put down the foot support and align it with the transmitting coil, and the spacing between the transmitting coil and the receiving coil is less than 30 mm, which can ensure that the charging power is stable when the transmitting coil and the receiving coil are unbalanced or placed at a large angle. The charging method is simple and intuitive, which can enhance the user experience. The foot support, as a carrier of the receiving coil, can accurately locate the coil position so that it is aligned with the optimal coupling position of the transmitting coil, thereby improving the energy transmission efficiency. At the same time, the foot support is usually kept at a certain distance from the ground, which provides a natural heat dissipation space for the receiving coil and the transmitting coil, which helps to control the temperature during the charging process and avoid overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the transmitting coil of the present invention.

[0022] Figure 2 It is a schematic diagram of the structure of the circular receiving coil of the present invention.

[0023] Figure 3 It is a schematic diagram of the structure of the elliptical receiving coil of the present invention.

[0024] Figure 4 It is a circuit schematic diagram of the present invention.

[0025] The reference numerals are as follows: 1 - charging circuit; 2 - receiving circuit; 3 - transmitting coil; 4 - receiving coil. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. It should be understood that the present application is not limited to the example embodiments disclosed herein. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The present invention provides Figures 1 to 4In an embodiment of the present invention, a wireless charging component is applied to an electric vehicle. The electric vehicle includes a vehicle body and a kickstand movably connected to the vehicle body, and also includes a charging module and a receiving module. The charging module includes a charging circuit 1 and a transmitting coil 3. The receiving module includes a receiving circuit 2 and a receiving coil 4. The receiving circuit 2 and the receiving coil 4 are electrically connected. The receiving module includes a receiving circuit 1 and a receiving coil 3. The receiving circuit 2 and the receiving coil 4 are electrically connected. The receiving circuit 2 is placed in the vehicle body, and the receiving coil 4 is arranged on the kickstand. The charging circuit 1 transmits electric energy to the receiving circuit 2 through electromagnetic induction between the transmitting coil 3 and the receiving coil 4. The electromagnetic induction spacing between the transmitting coil 3 and the receiving coil 4 is 0 to 30 mm.

[0031] Specifically, the mutual inductance of this combined coil is also optimal within a spacing of 30 mm, and the energy transfer loss is small within this spacing range, ensuring that the charging power is stable when the transmitting coil and the receiving coil are unbalanced or placed at a large angle.

[0032] The wireless transmission and reception circuit framework used in this application is as follows Figure 4 As shown, a MOS half-bridge circuit is used to drive the DC power into an AC signal. The transmitting coil L1 and the receiving coil L2 convert the magnetic field into electrical energy through electromagnetic coupling, and the AC voltage is converted back into a DC power supply through a rectifier bridge. The series capacitors C1 and C2 form a series resonance with L1 and L2 respectively to offset the influence of leakage magnetic field on energy transmission.

[0033] The coil resonant frequency is an important parameter of the system in wireless power transmission. The coil resonant frequency affects the loss of wireless charging energy transmission. The AC signal of the transmitting circuit works near the coil resonant frequency, and its transmission power, receiving power and transmission efficiency reach the highest; according to the inductance of the transmitting coil and the receiving coil and the capacitance value in series, the resonant frequency of the coil can be calculated as 48KhZ through the resonant frequency formula.

[0034] The resonant frequency formula is as follows:

[0035] The lower the resonant frequency, the smaller the wireless power transmission loss, the shorter the transmission distance, and the larger the required sending and receiving coil volume; after many experiments, the coil size and inductance value in this wireless charging coil combination technology are the optimal combination that meets 300W receiving power and conversion efficiency as well as lower charging temperature; at the same time, the mutual inductance of this combined coil is also optimal within a spacing of 3CM, and the energy transfer loss is small within this spacing range, ensuring stable charging power when the sending coil and the receiving coil are unbalanced or placed at a large angle.

[0036] Specifically, the receiving coil 4 is integrated on the kickstand, which makes full use of the space of the vehicle without occupying additional space inside the vehicle body or other locations. It also makes it more convenient to install or replace the coil. During maintenance, it is only necessary to remove the kickstand, which simplifies the maintenance process. When charging, the user only needs to put down the kickstand and ensure that it is aligned with the transmitting coil 3. This operation method is simple and intuitive, and can enhance the user's experience. The kickstand serves as a carrier of the receiving coil 4, and can accurately locate the coil position so that it is aligned with the optimal coupling position of the transmitting coil 3, thereby improving the energy transmission efficiency. The kickstand is usually kept at a certain distance from the ground, which provides a natural heat dissipation space for the receiving coil 4 and the transmitting coil 3, which helps to control the temperature during charging and avoid overheating.

[0037] Furthermore, the golden ratio of the transmitting coil 3 and the receiving coil 4 can be determined by the following steps:

[0038] S1. Determine the design parameters and specific requirements of the two-wheeled electric vehicle, such as the maximum charging distance, expected maximum power output, etc.;

[0039] S2. Theoretical analysis, using electromagnetic field theory to analyze the magnetic field distribution at different sizes and distances, involving Maxwell's equations;

[0040] S3. Simulation, using electromagnetic simulation software to perform detailed simulations to evaluate the performance of coils of different sizes and configurations, including analysis of magnetic field strength, coupling systems, and losses;

[0041] S4. Experimental verification: construct coil prototypes with different size ratios and test their performance in a laboratory environment. Compare the experimental results with theoretical predictions and simulation data to verify the accuracy of the model.

[0042] S5. Optimize the ratio. Based on the above analysis and experimental results, select an optimal ratio range that can meet specific design and power requirements while ensuring high coupling efficiency.

[0043] S6. Iterative improvement. In actual applications, the coil ratio can be further adjusted according to the specific application scenarios and user feedback to achieve the best transmission efficiency.

[0044] More specifically, under ideal conditions, assuming no edge effects and other losses, the mutual inductance M between the coils can be calculated by the mathematical expression:

[0045] Among them, N1 and N2 are the number of turns of the transmitting coil 3 and the receiving coil 4 respectively, A is the average cross-sectional area of ​​the coil, d is the distance between the coils, and μ0 is the magnetic permeability of the space. By changing the ratio of N1 and N2, the mutual inductance M can be adjusted, thereby affecting the overall efficiency and transmission power of the system. The golden ratio is determined based on the theoretical calculation and combined with the experimental structure. Specifically, the size ratio range of the transmitting coil 3 and the receiving coil 4 can be 1.5 to 3. Taking into account the various models of two-wheeled electric vehicles, as well as the limitations of vehicle design and space, within this size ratio range, the magnetic coupling effect between the transmitting coil 3 and the receiving coil 4 is better, which can effectively improve the energy transmission efficiency. When the sizes of the two coils are properly matched, the mutual inductance of the transmitting coil 3 and the receiving coil 4 is enhanced, thereby improving the efficiency of energy transfer.

[0046] The size ratio of the transmitting coil and the receiving coil can be a numerical ratio between their diameters, or a numerical ratio between their major axes or minor axes. The size of the transmitting coil 3 is 150 mm to 190 mm, and the size of the receiving coil 4 is 70 mm to 90 mm. Specifically, the outer diameter of the transmitting coil 3 is 150 mm, and 4 mm wire is used to wind 12 turns using the alpha winding method, and the receiving coil 4 is used to wind 8 turns using the alpha winding method using a 2.5 mm wire. Using a transmitting coil 3 with an outer diameter of 150 mm and a receiving coil 4 with a smaller diameter can provide sufficient coupling area to enhance the magnetic field interaction between the two coils, thereby increasing the mutual inductance and significantly improving the efficiency of energy transmission. The combination of a larger transmitting coil 3 and a smaller receiving coil 4 helps to focus the magnetic field distribution, ensuring that energy can still be effectively transmitted when the distance changes or the position deviates slightly.

[0047] Furthermore, the outer diameter of the transmitting coil 3 is 150 mm, and 4 mm wire is used to wind 12 turns using the Alpha winding method, and the receiving coil 4 is used to wind 8 turns using the Alpha winding method using a 2.5 mm wire. The Alpha winding method helps to achieve a more uniform magnetic field distribution through a specific coil arrangement and stacking method. This uniformity is essential for improving the coupling efficiency between the transmitting coil 3 and the receiving coil 4, thereby improving the charging efficiency of the entire system, and a good coil structure can reduce the leakage of magnetic flux, which means that more magnetic field lines pass through the receiving coil 4, thereby improving the efficiency of energy transmission.

[0048] Furthermore, the wire of the transmitting coil 3 is 4 mm, which has a lower resistance and generates less heat under the same current conditions, which helps to reduce heat accumulation during system operation and extend the service life of electronic components. The thicker coil can withstand greater current without overheating, which increases the robustness when facing sudden loads or unstable grid conditions. Considering the overall structure of the two-wheeled electric vehicle, the receiving coil 4 uses a 2.5 mm wire.

[0049] The receiving coil 4 is circular or elliptical. Circular and elliptical coils can provide a more uniform magnetic field distribution, thereby improving the electromagnetic induction coupling efficiency between the transmitting coil 3 and the receiving coil 4. This uniform coupling helps to improve the efficiency and stability of energy transmission. Due to the flexibility of the shape, both circular and elliptical coils can adapt to different vehicle kickstand designs and the personalized needs of different users for charging positions.

[0050] Specifically, the size of the circular receiving coil 4 can be 85mm. The 85mm receiving coil 4 is moderately sized and can be applied to a variety of two-wheeled electric vehicles. This flexibility allows the wireless charging solution to be widely used in various vehicle models on the market without the need to design a dedicated receiving coil 4 for each vehicle model. Selecting a circular receiving coil 4 with a diameter of 85mm can be well matched with the transmitting coil 3 to ensure effective electromagnetic coupling between the two. Coils of this size help maximize magnetic flux linkage, thereby improving the efficiency of energy transmission. Preferably, the receiving coil 4 can also be 80mm and 90mm in size.

[0051] The sizes of the elliptical receiving coil 4 are 70mm and 90mm. Specifically, the long axis of the elliptical receiving coil 4 can be 90mm or 70mm, and the short axis can be 70mm or 90mm. The elliptical receiving coil 4 can more easily adapt to different installation spaces and foot support designs. The size changes of its long and short axes provide more design flexibility, allowing the coil to be better integrated into electric vehicles with various size and shape restrictions; due to the elliptical structure, users have more room for error when placing and aligning the receiving coil 4 in actual operation. Compared with circular coils, elliptical coils can also maintain higher charging efficiency when not precisely aligned.

[0052] It also includes a magnetic isolation sheet and a plastic lower cover; the transmitting coil 3, the magnetic isolation sheet and the plastic lower cover are stacked in sequence. The transmitting coil 3 is fixed on the magnetic isolation sheet, which is used to reduce the magnetic field range of the transmitting coil. The magnetic isolation sheet is used to guide and concentrate the magnetic field lines so that they can pass through the receiving coil 4 more effectively. By reducing the lateral diffusion of the magnetic field, the magnetic isolation sheet helps to improve the coupling efficiency between the transmitting coil 3 and the receiving coil 4, thereby improving the charging efficiency of the entire system. The magnetic isolation sheet can also block external magnetic interference and ensure the purity of the magnetic field, which is crucial to maintaining the stability and charging efficiency of the system; and the plastic lower cover provides a physical protective layer to prevent the entry of objects such as water or dust from the external environment, resulting in damage to the transmitting coil 3 and other sensitive components, which prolongs the service life of the components and maintains their performance, which also allows the transmitting coil 3 to be buried underground to save space on the ground.

[0053] The diameter range of the magnetic isolation sheet is 150mm to 190mm, and the size of the magnetic isolation sheet is adapted to the transmitting coil 3. By ensuring that the size of the magnetic isolation sheet matches the transmitting coil 3, the magnetic field can be more effectively concentrated and guided. This optimized magnetic field distribution helps to improve the coupling efficiency between the transmitting coil 3 and the receiving coil 4, thereby improving the energy transmission efficiency of the entire system. The magnetic isolation sheet with adapted size can reduce the lateral diffusion and leakage of the magnetic field, ensuring that more magnetic lines of force can effectively pass through the receiving coil 4, thereby improving the overall performance of the system.

[0054] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "including a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0055] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wireless charging assembly, applied to an electric vehicle, the electric vehicle comprising a vehicle body and a kickstand movably connected to the vehicle body, characterized in that: Also includes a charging module and a receiving module; The charging module comprises a charging circuit and a transmitting coil, and the charging circuit is electrically connected to the transmitting coil; The receiving module includes a receiving circuit and a receiving coil, and the receiving circuit and the receiving coil are electrically connected; The receiving coil is arranged on the foot support; The charging circuit transmits electric energy to the receiving circuit through electromagnetic induction between the transmitting coil and the receiving coil; The electromagnetic induction distance between the transmitting coil and the receiving coil is less than 30 mm, and the size ratio of the transmitting coil to the receiving coil is 1.5-3.

2. A wireless charging assembly according to claim 1, characterized in that: The size of the transmitting coil is 150 mm to 190 mm, and the size of the receiving coil is 70 mm to 90 mm.

3. A wireless charging assembly according to claim 2, characterized in that: The transmitting coil is made of 4 mm wire and is wound 12 times using the Alpha winding method.

4. A wireless charging assembly according to claim 2, characterized in that: The receiving coil is made of 2.5 mm wire, wound with 8 turns, and the winding method adopted is the Alpha winding method.

5. The wireless charging assembly according to claim 1, characterized in that: The receiving coil is sleeved on the foot support, and the receiving coil includes a circular shape and an elliptical shape.

6. A wireless charging assembly according to any one of claims 1 to 5, characterized in that: The charging module also includes a magnetic isolation sheet and a plastic lower cover; The transmitting coil, the magnetic isolation sheet and the plastic lower cover are stacked in sequence.

7. A wireless charging assembly according to claim 6, characterized in that: The transmitting coil is fixed on the magnetic isolation sheet, and the magnetic isolation sheet is used to reduce the magnetic field range of the transmitting coil.

8. The wireless charging assembly according to claim 5, characterized in that: The diameter of the circular receiving coil is 85 mm.

9. The wireless charging assembly according to claim 5, characterized in that: The major axis of the elliptical receiving coil is 90 mm, and the minor axis is 70 mm.

10. The wireless charging assembly according to claim 6, characterized in that: The shape of the magnetic isolation sheet matches the shape of the transmitting coil.

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