Vehicle-mounted bidirectional wireless charging panel of electric bicycle

Abstract

The invention discloses a vehicle-mounted two-way wireless charging disc device of an electric bicycle. The vehicle-mounted two-way wireless charging disc device comprises the following parts: 1) a rear end cover shell; 2) a compensation and control circuit; 3) a shielding layer aluminum plate; 4) a ferrite magnetic core; 5) a DD type high-power receiving coil; 6) a circular low-power transmitting coil; and 7) a front end cover shell. The core is that the DD type high-power receiving coil (5) adopts a DD type coil structure and can be decoupled with the circular low-power transmitting coil (6) on a magnetic field, so that the two charging loops do not interfere with each other. Wherein the DD type high-power receiving coil (5) is used for wirelessly charging an electric bicycle, and the circular low-power transmitting coil (6) is used for wirelessly charging a vehicle-mounted mobile phone by the electric bicycle. Meanwhile, the forward charging channel and the reverse charging channel work at different resonant frequencies. In addition, wave-blocking filters are arranged in the two channels, and the wave-blocking frequency of the wave-blocking filters and the resonant frequency of the other channel are suppressed, so that the frequency interference of the corresponding channel is suppressed.

Description

Technical Field

[0001] This invention relates to wireless charging technology for electric bicycles, specifically a bidirectional wireless charging circuit device installed on an electric bicycle. Background Technology

[0002] Over the past decade, wireless charging technology has developed rapidly and has been quickly applied in various fields, such as portable electronic devices like mobile phones and tablets, AGV robots, implantable medical devices, and electric vehicles. Compared to traditional wired charging methods, wireless charging has no exposed interfaces, making it safer and more convenient, and thus has significant market demand and development potential.

[0003] Among the many applications of wireless charging, wireless charging for electric bicycles is a significant one. Wireless charging technology allows for both charging the electric bicycle's own battery and wirelessly charging the rider's mobile phone from the bicycle's battery. Because wireless charging devices have no exposed interfaces, they are waterproof, rainproof, and leak-proof, offering better environmental adaptability. The market for wireless charging devices for electric bicycles is enormous. Preliminary market research indicates that by the end of 2021, the number of electric bicycles in China reached 300 million, with annual shipments approaching 40 million. The application of wireless charging technology for electric bicycles not only brings charging convenience to electric bicycle users but also promotes the development of the wireless charging industry chain.

[0004] However, current wireless charging devices for electric bicycles only have unidirectional wireless charging functionality. That is, they can either wirelessly charge the electric bicycle battery through a charging station or wirelessly charge the rider's navigation phone using the electric bicycle battery. They cannot achieve the integration of these two functions.

[0005] To address the above problems, this invention proposes a "bidirectional wireless charging pad for electric bicycles," capable of simultaneously charging the following two... 1 Functions: 1) Wirelessly charge the electric bicycle battery through the charging terminal on the front cover; 2) Wirelessly charge the rider's navigation phone using the electric bicycle battery. The principle and structure of the device are described below. Summary of the Invention

[0006] This invention mainly relates to an "electric bicycle on-board bidirectional wireless charging pad" device, comprising the following parts: 1) front cover housing; 2) compensation and control circuit; 3) shielding aluminum plate; 4) ferrite core; 5) DD-type high-power receiving coil; 6) circular low-power transmitting coil; 7) rear cover housing. The functions of each part are as follows:

[0007] 1) The front cover housing and 7) the rear cover housing are used together to seal the five parts 2) to 6) inside the housing.

[0008] 5) DD-type high-power receiving coil, used for wireless charging of electric bicycle batteries. This coil is a receiving coil. In actual use, the transmitting coil from the charging station needs to be attached to the on-board bidirectional wireless charging pad for wireless power transmission. The transmitting coil is also designed as a DD-type coil structure.

[0009] 6) A circular, low-power transmitting coil is used to wirelessly charge the rider's navigation phone. This coil is the transmitting coil. In actual use, the rider's phone needs to be placed in contact with the vehicle-mounted bidirectional wireless charging pad to wirelessly transmit power. The phone's built-in receiving coil is also set as a circular coil structure.

[0010] 4) Ferrite cores are used to enhance the magnetic field coupling between 5) the high-power receiving coil of the DD type and its corresponding transmitting coil, and also to enhance the magnetic field coupling between 6) the circular low-power transmitting coil and its corresponding receiving coil. Simultaneously, ferrite cores can also create low magnetic reluctance paths, reducing the leakage radiation of high-frequency magnetic fields.

[0011] 2) Compensation and control circuit, connected to 5) DD-type high-power receiving coil and 6) circular low-power transmitting coil, providing compensation topology (such as series resonant capacitors and band-stop filters based on parallel resonance) and control circuit. The control circuit used for 5) DD-type high-power receiving coil is 2.

[0012] The high-frequency rectifier circuit, used in the control circuit of the circular low-power transmitting coil (6), is a high-frequency inverter circuit. In addition, the control circuit also includes a communication module and a controller unit.

[0013] 3) Aluminum shielding plate, used to further reduce external radiation of high-frequency magnetic field and provide heat dissipation channels for 4) ferrite core and power devices on compensation and control circuit.

[0014] Specifically, the 5) DD-type high-power receiving coil adopts a DD-type coil structure to achieve magnetic field decoupling from the 6) circular low-power transmitting coil. Furthermore, the 5) DD-type high-power receiving coil and the 6) circular low-power transmitting coil use different resonant frequencies. Specifically, the resonant frequency of the 5) DD-type high-power receiving coil is in the range of 50-60kHz, while the resonant frequency of the 6) circular low-power transmitting coil is in the range of 80-120kHz. Using different resonant frequencies effectively reduces mutual interference between the high-power charging circuit and the low-power charging circuit. Further, in the compensation topology of the 5) DD-type high-power receiving coil, a band-stop filter is connected in series, with its band-stop frequency consistent with the resonant frequency of the 6) circular low-power transmitting coil; a band-stop filter is also added to the compensation topology of the 6) circular low-power transmitting coil, with its band-stop frequency consistent with the resonant frequency of the 5) DD-type high-power receiving coil, thereby further reducing mutual interference between the two coil paths.

[0015] The present invention has the following advantages:

[0016] • When the transmitting coil from the charging station is attached to the vehicle-mounted bidirectional wireless charging pad, it can wirelessly charge the on-board battery of the electric bicycle through the 5)DD type high-power receiving coil.

[0017] • When the rider's navigation phone is attached to the vehicle's bidirectional wireless charging pad, it can wirelessly charge the rider's navigation phone via a circular low-power transmitting coil (6).

[0018] ·5) The DD-type high-power receiving coil and 6) the circular low-power transmitting coil have natural decoupling characteristics in their coil structure, and the mutual interference between the two channels can be further eliminated by setting different operating frequency bands and adding band-stop filters. Attached Figure Description

[0019] Appendix Figure 1 This is a component diagram of a dual 3-way wireless charging pad for electric bicycles.

[0020] Appendix Figure 2 Diagram showing the relative positions of the DD-type high-power receiving coil and the circular low-power transmitting coil.

[0021] Appendix Figure 3 For the compensation and control circuit structure diagram

[0022] Appendix Figure 4 Schematic diagram of wireless charging of electric bicycles using charging stations

[0023] Appendix Figure 5 Equivalent circuit diagram for wireless charging of electric bicycles using charging stations

[0024] Appendix Figure 6Diagram illustrating wireless charging of a mobile phone using an electric bicycle.

[0025] Appendix Figure 7 Equivalent circuit diagram for wireless charging of mobile phones from electric bicycles

[0026] Specific implementation methods

[0027] An electric bicycle onboard bidirectional wireless charging pad includes two power transmission coils: 5) a DD-type high-power receiving coil and 6) a circular low-power transmitting coil. The dimensions and structure of the two power transmission coils are as follows... Figure 2 As shown, 5) the outer boundary dimensions of the DD-type high-power receiving coil are 55mm*XXmm, and the self-inductance is 32uH. 6) The inner and outer diameters of the circular low-power transmitting coil are 18mm*38mm, and the self-inductance is 8uH. The mutual inductance between the two power transmission coils is 0.24uH, which shows that the mutual inductance between the two coils is almost negligible, thus achieving decoupling.

[0028] The structure of the compensation and control circuit of a two-way wireless charging pad for electric bicycles is shown in the figure. Figure 3 As shown. Among them, the DD type high-power receiving coil (i.e., L) is the same as 5). B1 The compensation capacitor (i.e., C) connected to the circuit. B1 The current is 220nF, forming a resonant frequency of 60kHz; and 6) a circular low-power transmitting coil (i.e., L) M1 The compensation capacitor (i.e., C) connected to the circuit. M1 The current is 330nF, forming a resonant frequency of 98kHz. Furthermore, in the resonant circuit of the 5)DD-type high-power receiving coil, a parallel resonant topology (i.e., C) is connected in series. B2 L B2 A band-stop filter, with a resonant frequency of 98kHz, is constructed to eliminate the influence of the circular low-power transmitting coil (6) on the high-power receiving coil (5) of type DD. Similarly, a parallel resonant topology (i.e., C) is connected in series in the resonant circuit of the circular low-power transmitting coil (6). M2 L M2 A band-stop filter, with a resonant frequency of 60kHz, is constructed to eliminate the influence of the DD-type high-power receiving coil on the circular low-power transmitting coil. The resonant circuit of the DD-type high-power receiving coil is connected to a full-bridge rectifier to convert the received high-frequency AC power into DC power for the electric motor. 4The vehicle's onboard battery is charged. 6) A full-bridge inverter bridge is connected to the resonant circuit of the circular low-power transmitting coil to generate high-frequency AC power, which excites the circular low-power transmitting coil to output electrical energy to wirelessly charge the rider's navigation phone. Specifically, the DC power supply of this full-bridge inverter bridge is 5-12V, generated by stepping down the voltage of the electric bicycle's onboard battery. In addition, 2) the compensation and control circuit also has a controller MCU and communication components to control the charging process and exchange information with other devices.

[0029] The process of wireless charging for electric bicycles is as follows Figure 4 As shown, the wireless charging transmitter on the charging station is tightly attached to the vehicle-mounted bidirectional wireless charging pad. The wireless charging transmitter on the charging station also contains a DD-type high-power transmitting coil, which, together with the DD-type high-power receiving coil on the vehicle-mounted bidirectional wireless charging pad, forms a coil pair to achieve wireless power transmission. The circuit structure for wireless charging of the electric bicycle's onboard battery is as follows. Figure 5 As shown, the charging pile is the transmitting side, which includes units such as a DC power supply, a high-frequency inverter, a resonant topology, and a transmitting coil. Depending on different requirements, the resonant topology of the transmitting end can adopt different compensation topologies, such as LCC topology or series resonant topology.

[0030] The process of wirelessly charging a mobile phone using an electric bicycle is as follows: Figure 6 As shown, the rider's navigation phone is tightly attached to the vehicle's bidirectional wireless charging pad. The phone being charged also contains a circular wireless charging receiver coil, which, together with the circular low-power transmitter coil (6) on the vehicle's bidirectional wireless charging pad, forms a coil pair to achieve wireless power transmission. The circuit structure for wireless charging of the phone is as follows... Figure 7 As shown, the mobile phone is the receiving side, which includes units such as a receiving coil, a compensation capacitor, a rectifier bridge, and a charging management chip.

[0031] In summary, the key to this invention lies in the design of a dual-coil vehicle-mounted bidirectional wireless charging pad with self-decoupling characteristics. The high-power receiving coil for wireless charging electric bicycles employs a DD-type coil structure, while the low-power transmitting coil for wireless charging mobile phones adopts a circular structure. By setting different resonant frequencies and adding a band-stop filter, mutual decoupling between the two coil channels is achieved. Thus, during the wireless charging process of electric bicycles, no interference occurs on the low-power coil.

[0032] It generates induced current; during the wireless charging of mobile phones, no induced current is generated in the high-power coil.

[0033] It should be noted that the above embodiments are merely illustrative of the basic principles of the present invention. Those skilled in the art can make various modifications and variations based on the present invention without departing from its spirit and scope. If such modifications and variations fall within the scope of the claims of the present invention and their equivalents, they are all within the protection scope of the present invention.

Claims

1. A bidirectional wireless charging pad for electric bicycles, characterized in that: The system comprises the following components: 1) rear end cover housing; 2) compensation and control circuit; 3) shielding aluminum plate; 4) ferrite core; 5) DD-type high-power receiving coil; 6) circular low-power transmitting coil; and 7) front end cover housing. The core component is that the DD-type high-power receiving coil (5) employs a DD-type coil structure, which decouples it from the circular low-power transmitting coil (6) in the magnetic field, preventing interference between the two charging circuits. The DD-type high-power receiving coil (5) is used for wireless charging of electric bicycles, while the circular low-power transmitting coil (6) is used for wireless charging of mobile phones from the electric bicycle. Furthermore, the forward and reverse charging channels operate at different resonant frequencies. Further, a band-stop filter is connected in series in the compensation topology of the DD-type high-power receiving coil, with its band-stop frequency matching the resonant frequency of the circular low-power transmitting coil (6); a band-stop filter is also added to the compensation topology of the circular low-power transmitting coil (6), with its band-stop frequency matching the resonant frequency of the DD-type high-power receiving coil, thereby further eliminating mutual interference between the two coil paths.

2. The vehicle-mounted bidirectional wireless charging pad as described in claim 1, characterized in that: The circuit components connected to the 5)DD type high-power receiving coil include: a) a compensation capacitor, used to form a resonant circuit with the 5)DD type high-power receiving coil to realize the reception of high-frequency magnetic field energy; b) a band-stop filter, used to eliminate the influence of the 6) circular low-power transmitting coil on the 5)DD type high-power receiving coil, and to avoid the generation of induced current in the 5)DD type high-power receiving coil when the 6) circular low-power transmitting coil is working; c) a full-bridge rectifier bridge, used to convert the received high-frequency electrical energy into DC electrical energy; d) a rectifier bridge output filter capacitor, which performs voltage regulation and filtering on the output of the rectifier bridge to charge the electric bicycle's on-board battery.

3. The vehicle-mounted bidirectional wireless charging pad as described in claim 1, characterized in that: The circuit components connected to the circular low-power transmitting coil (6) include: a) a compensation capacitor, used to form a resonant circuit with the circular low-power transmitting coil (6) to realize the transmission of high-frequency magnetic field energy; b) a band-stop filter, used to eliminate the influence of the DD-type high-power receiving coil (5) on the circular low-power transmitting coil (6) and avoid the generation of induced current in the circular low-power transmitting coil (6) when the DD-type high-power receiving coil (5) is working; c) a full-bridge inverter bridge, used to convert the vehicle's DC power into high-frequency AC power; and d) a step-down DC / DC converter, used to reduce the vehicle's battery voltage to the 5-12V range required for wireless charging of mobile phones.

4. The vehicle-mounted bidirectional wireless charging pad as described in claim 1, characterized in that: The resonant frequency of the forward channel for wireless charging of electric bicycles is 50-60kHz; the resonant frequency of the reverse channel for wireless charging of mobile phones is 80-120kHz. There is a frequency difference of 30-60kHz between the two.

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