Anti-offset coupling mechanism and system for wireless power transfer and control method

Abstract

The application discloses an anti-deviation coupling mechanism and system for wireless power transmission and a control method, and the coupling mechanism comprises a primary coil and a secondary coil, and is characterized in that the secondary coil is formed into three independent receiving coils in a three-wire parallel winding mode, the three independent receiving coils are connected in series with each other, and at least two of the receiving coils are respectively provided with short-circuit control circuits. The effect is that the application can increase the deviation range of the primary coil and the secondary coil by changing the winding mode of the secondary coil and cooperating with the secondary control circuit, so that the application scene of the wireless power transmission technology is wider.

Description

Technical Field

[0001] This invention relates to wireless power transmission technology, and more specifically, to an anti-offset coupling mechanism, system, and control method for wireless power transmission. Background Technology

[0002] Currently, wireless power transfer technology mainly uses a fixed distance (determined primary and secondary side spacing) and direct alignment (center alignment of primary and secondary sides) for power transfer. However, as the mobility requirements of the receiver increase, for some application scenarios, such as intelligent sorting robots, the receiver often needs to move back and forth along a preset track, causing changes in the distance between the primary and secondary sides. When the distance increases, the mutual inductance decreases; when the distance decreases, the mutual inductance increases. Furthermore, when the primary and secondary sides are offset in a plane, the mutual inductance also decreases. To obtain a voltage that allows the load to operate stably, a DC-DC voltage regulator module is typically added after the rectifier at the receiver. This DC-DC voltage regulator module has a predetermined input voltage range. However, in existing technologies, due to the weak anti-offset capability of the coupling mechanism and system control, when the primary and secondary sides are offset, the increase or decrease in the mutual inductance often leads to an increase or decrease in the rectified output voltage of the secondary side. The rectified output voltage may fail to meet the input voltage range of the DC-DC converter, resulting in power transfer interruption or even damage to the DC-DC module. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an anti-offset coupling mechanism for wireless power transmission. By employing multi-wire parallel winding in the secondary coil, the anti-offset capability of the system can be satisfied by adjusting the number of receiving coils connected.

[0004] To achieve the above objectives, the specific technical solution adopted by the present invention is as follows:

[0005] An anti-offset coupling mechanism for wireless power transmission includes a primary coil and a secondary coil. The key feature is that the secondary coil is formed into three independent receiving coils by a three-wire parallel winding method. The three independent receiving coils are connected in series and at least two of the receiving coils are respectively provided with short-circuit control circuits.

[0006] Optionally, the primary coil and the secondary coil are wound into a circle, rectangle, ellipse or figure-eight shape.

[0007] Optionally, the primary coil and the secondary coil are directly opposite each other, their centers are always on the same central axis, and the secondary coil moves along the central axis.

[0008] Optionally, a compensation capacitor is connected in series with each receiving coil to form a series resonant section, and the short-circuit control circuit is used to control the two ends of a corresponding series resonant section to form a short circuit.

[0009] Based on the above coupling mechanism, the present invention also provides an anti-offset system for wireless power transmission. Employing the aforementioned anti-offset coupling mechanism for wireless power transmission, a high-frequency AC signal is connected to the primary coil via an LCC compensation network. A rectifier filter circuit and an electrical load are connected to the secondary coil. A voltage detection module is also provided at the output of the rectifier filter circuit. The voltage detection module inputs the detected voltage signal into a control module, which controls the short-circuit control circuit to switch between short-circuit states.

[0010] Optionally, the secondary coil and the primary coil move along the central axis within a preset distance range while facing each other.

[0011] Based on the anti-migration system described above, the present invention also provides an anti-migration method for wireless power transmission, which employs the anti-migration system described above and includes the following steps:

[0012] S1: Set the initial state to the two-coil connected state. The first and second receiving coils are connected to the secondary main circuit, the third receiving coil is short-circuited, and the primary coil works according to the rated output power.

[0013] S2: When both coils are connected, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the output voltage of the rectifier and filter circuit through the voltage detection module.

[0014] When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V1, the control module controls the second receiving coil to disconnect from the secondary main circuit through the short-circuit control circuit, and the system enters the single coil connection state.

[0015] When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V4, the control module controls the third receiving coil to connect to the secondary main circuit through the short-circuit control circuit, and the system enters the three-coil connection state.

[0016] S3: In the single-coil connection state, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the rectifier and filter circuit output through the voltage detection module.

[0017] When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V1, the control module triggers the safety protection and stops the primary coil from working.

[0018] When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V3, the control module controls the second receiving coil to connect to the secondary main circuit through the short-circuit control circuit, and the system returns to the state of two coils connected.

[0019] With the three coils connected, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the output voltage of the rectifier and filter circuit through the voltage detection module.

[0020] When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V4, the control module triggers the safety protection and stops the primary coil from working.

[0021] When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V6, the control module controls the third receiving coil to disconnect from the secondary main circuit through the short-circuit control circuit, and the system returns to the state of two coils connected.

[0022] Optionally, the voltage threshold V4 < voltage threshold V6 < voltage threshold V3 < voltage threshold V1, and the rated voltage V7 output by the rectifier filter circuit under the rated distance condition satisfies: voltage threshold V6 < rated voltage V7 < voltage threshold V3.

[0023] The significant advantage of this invention is that by changing the winding method of the secondary coil and cooperating with the secondary control circuit, the offset range of the primary and secondary sides can be increased, making the application scenarios of wireless power transmission technology more extensive. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of an anti-offset coupling mechanism structure for wireless power transmission provided in a specific embodiment of the present invention;

[0026] Figure 2 This is a circuit diagram of an anti-offset system for wireless power transmission provided in a specific embodiment of the present invention;

[0027] Figure 3 This is a voltage threshold relationship diagram in an anti-offset method for wireless power transmission provided in a specific embodiment of the present invention;

[0028] Figure 4 This is a control flowchart of an anti-offset method for wireless power transmission provided in a specific embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] like Figure 1 As shown, this embodiment provides an anti-offset coupling mechanism for wireless power transmission, including a primary coil and a secondary coil. The secondary coil is formed into three independent receiving coils using a three-wire parallel winding method. The three independent receiving coils are connected in series, and at least two of the receiving coils are respectively provided with short-circuit control circuits. In specific implementation, the primary coil is wound with ordinary single wire, and the winding shape is circular, rectangular, elliptical, figure-eight, etc. The secondary coil is wound with three wires in parallel and follows the same outline shape as the primary coil. The outer diameters of the primary coil and the secondary coil are the same.

[0032] This embodiment uses a sorting robot as an example. Both the primary and secondary coils are planar circular spiral coils, facing each other directly, with their centers always on the same central axis, and the secondary coil moves along the central axis. In specific implementation, a compensation capacitor is connected in series with each receiving coil to form a series resonant segment, and a short-circuit control circuit is used to control the two ends of a corresponding series resonant segment to form a short circuit.

[0033] Combination Figure 2 It can be seen that the above coupling mechanism constitutes an anti-offset system for wireless power transmission. A high-frequency AC signal is connected to the primary coil through an LCC compensation network. A rectifier and filter circuit and an electrical load are connected to the secondary coil. A voltage detection module is also provided at the output of the rectifier and filter circuit. The voltage detection module inputs the detected voltage signal into the control module. The control module is used to control the short-circuit control circuit to achieve short-circuit state switching.

[0034] Figure 2In the circuit, L4 is the first receiving coil, L1 is the second receiving coil, L5 is the third receiving coil, and L3 is the primary coil. Inductor L2, capacitor C3, and capacitor C7 form an LCC compensation network. Capacitor C1 is the compensation capacitor for L1, capacitor C4 is the compensation capacitor for L4, and capacitor C8 is the compensation capacitor for L5. The short-circuit control circuit is implemented using a set of switching transistors and corresponding drive modules. Diodes D1, D2, D3, D4, and capacitor 5 form the secondary rectifier and filter circuit. R2 is the load resistor, and R1 and R3 form the voltage sampling module. The MCU is the control module.

[0035] In practice, the secondary coil and the primary coil move along the central axis within a preset distance range while facing each other. The movement range of the secondary coil can be controlled by setting a limiting mechanism to keep the picked-up voltage within a reasonable range and reduce the system's triggering of protection.

[0036] Combination Figure 3 and Figure 4 As shown, based on the anti-migration system described above, this embodiment also provides an anti-migration method for wireless power transfer, including the following steps:

[0037] S1: Set the initial state to the two-coil connected state. The first and second receiving coils are connected to the secondary main circuit, the third receiving coil is short-circuited, and the primary coil works according to the rated output power.

[0038] S2: When both coils are connected, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the output voltage of the rectifier and filter circuit through the voltage detection module.

[0039] When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V1, the control module controls the second receiving coil to disconnect from the secondary main circuit through the short-circuit control circuit, and the system enters the single coil connection state.

[0040] When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V4, the control module controls the third receiving coil to connect to the secondary main circuit through the short-circuit control circuit, and the system enters the three-coil connection state.

[0041] S3: In the single-coil connection state, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the rectifier and filter circuit output through the voltage detection module.

[0042] When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V1, the control module triggers the safety protection and stops the primary coil from working.

[0043] When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V3, the control module controls the second receiving coil to connect to the secondary main circuit through the short-circuit control circuit, and the system returns to the state of two coils connected.

[0044] With the three coils connected, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the output voltage of the rectifier and filter circuit through the voltage detection module.

[0045] When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V4, the control module triggers the safety protection and stops the primary coil from working.

[0046] When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V6, the control module controls the third receiving coil to disconnect from the secondary main circuit through the short-circuit control circuit, and the system returns to the state of two coils connected.

[0047] Optionally, the voltage threshold V4 < voltage threshold V6 < voltage threshold V3 < voltage threshold V1, and the rated voltage V7 output by the rectifier filter circuit under the rated distance condition satisfies: voltage threshold V6 < rated voltage V7 < voltage threshold V3.

[0048] Combination Figure 3 and Figure 4 Initially, the primary and secondary coils are positioned appropriately. The first receiving coil L4 and the second receiving coil L1 are connected to the secondary main circuit. The output voltage of the secondary rectifier filter is between the voltage thresholds V6 and V3. As the secondary coil gradually approaches the primary coil, the mutual inductance increases. When the output voltage of the secondary rectifier filter exceeds the voltage threshold V1, the second receiving coil L1 is disconnected from the secondary main circuit via a short circuit. At this point, the system enters a single-coil connection state, and the voltage should decrease to the voltage threshold V2. If the secondary coil continues to approach the primary coil, causing the mutual inductance to continue to increase and the output voltage of the secondary rectifier filter to exceed the voltage threshold V1 again, the system triggers high-voltage protection. If, in the single-coil connection state, the secondary coil begins to return and gradually moves away from the primary coil, the mutual inductance will gradually decrease. When the secondary rectifier filter... When the output voltage of the filter is lower than the voltage threshold V3, the second receiving coil L1 is reconnected to the secondary main circuit. As the secondary coil continues to move away from the primary coil, causing the output voltage of the secondary rectifier filter to fall below the voltage threshold V4, the third receiving coil L5 is connected to the secondary main circuit. At this time, the system enters a three-coil connection state, and the mutual inductance can be increased. The voltage should be increased to the voltage threshold V5. If the secondary coil continues to move away from the primary coil, causing the output voltage of the secondary rectifier filter to fall below the voltage threshold V4 again, the system triggers low-voltage protection. If the secondary coil begins to return and gradually move closer to the primary coil, the mutual inductance will gradually increase. When the output voltage of the secondary rectifier filter is higher than the voltage threshold V6, the third receiving coil L5 is short-circuited and disconnected from the secondary main circuit, and the system returns to the initial two-coil connection state.

[0049] In summary, by modifying the winding method of the secondary coil and cooperating with the secondary control circuit, this invention can adjust the number of receiving coils connected according to the changes in the pickup voltage, thereby increasing the offset range of the primary and secondary sides. At the same time, when controlling the connection, the voltage threshold is set with a hysteresis range, which can effectively reduce the switching frequency and improve the stability of the system output when the offset distance changes repeatedly, making the application scenarios of wireless power transmission technology more extensive.

[0050] Finally, it should be noted that the technical solutions disclosed above are only a preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes in accordance with the claims of the present invention still fall within the scope of the invention.

Claims

1. An anti-migration system for wireless power transfer, characterized in that: An anti-offset coupling mechanism is adopted, comprising a primary coil and a secondary coil. The secondary coil is wound with three wires in parallel to form three independent receiving coils. These three independent receiving coils are connected in series, and at least two of them are equipped with short-circuit control circuits. A high-frequency AC signal is connected to the primary coil via an LCC compensation network. A rectifier and filter circuit and an electrical load are connected to the secondary coil. A voltage detection module is also provided at the output of the rectifier and filter circuit. The voltage detection module inputs the detected voltage signal to a control module, which controls the short-circuit control circuit to switch between short-circuit states. The specific steps include: S1: Set the initial state to the two-coil connected state. The first and second receiving coils are connected to the secondary main circuit, the third receiving coil is short-circuited, and the primary coil works at the rated output power. S2: When both coils are connected, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the output voltage of the rectifier and filter circuit through the voltage detection module. When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V1, the control module controls the second receiving coil to disconnect from the secondary main circuit through the short-circuit control circuit, and the system enters the single coil connection state. When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V4, the control module controls the third receiving coil to connect to the secondary main circuit through the short-circuit control circuit, and the system enters the three-coil connection state. S3: In the single-coil connection state, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the rectifier and filter circuit output through the voltage detection module. When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V1, the control module triggers the safety protection and stops the primary coil from working. When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V3, the control module controls the second receiving coil to connect to the secondary main circuit through the short-circuit control circuit, and the system returns to the state of two coils connected. With the three coils connected, as the positions of the secondary coil and the primary coil change, the control module detects the voltage change of the output voltage of the rectifier and filter circuit through the voltage detection module. When the voltage output by the rectifier and filter circuit is lower than the voltage threshold V4, the control module triggers the safety protection and stops the primary coil from working. When the voltage output by the rectifier and filter circuit is higher than the voltage threshold V6, the control module controls the third receiving coil to disconnect from the secondary main circuit through the short-circuit control circuit, and the system returns to the state of two coils connected.

2. The anti-offset system according to claim 1, characterized in that: The primary coil and the secondary coil are wound into a circle, rectangle, ellipse or figure-eight shape.

3. The anti-displacement system according to claim 1 or 2, characterized in that: The primary coil and the secondary coil are directly opposite each other, and their centers are always on the same central axis, with the secondary coil moving along the central axis.

4. The anti-displacement system according to claim 3, characterized in that: Each receiving coil is connected in series with a compensation capacitor to form a series resonant section. The short-circuit control circuit is used to control the two ends of a corresponding series resonant section to form a short circuit.

5. The anti-displacement system according to claim 1, characterized in that: The secondary coil and the primary coil move along the central axis within a preset distance range while facing each other.

6. The anti-displacement system according to claim 5, characterized in that: The voltage threshold V4 < voltage threshold V6 < voltage threshold V3 < voltage threshold V1, and the rated voltage V7 output by the rectifier filter circuit under the rated distance condition satisfies: voltage threshold V6 < rated voltage V7 < voltage threshold V3.

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