Adaptive adjustment device and method for variable distance wireless energy transmission

Abstract

The present invention proposes an adaptive adjustment device and method for variable distance wireless energy transmission, which realizes high-efficiency transmission of electric energy at different transmission distances by offsetting the source coil and the transmitting coil and / or the load coil and the receiving coil by a certain distance. The device includes one or two guide rails (or other types of mechanisms that can achieve translation), a transmitting coil and a receiving coil, a source coil and a load coil; the source coil is fixed on the guide rail and can be offset to form a certain distance with the transmitting coil by adjustment; the load coil is fixed on another guide rail and can be offset to form a certain distance with the receiving coil by adjustment; the source coil and the load coil can be adjusted to a certain offset distance at the same time or the offset distance can be adjusted independently. The present invention can ensure high-efficiency energy transmission at different transmission distances, and can solve the problem that the transmission efficiency of traditional magnetic resonance wireless energy transmission decreases sharply as the transmission distance changes.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless energy transmission, and in particular, relates to an adaptive adjustment device and method for variable-distance wireless energy transmission, which uses adjustable coupling technology in a magnetic resonance wireless energy transmission system to achieve high-efficiency energy transmission at different transmission distances. Background Art

[0002] Wireless power transmission (WPT) has been a hot topic in recent decades. Since Nicola Tesla, people have made great efforts in WPT. As early as 1902, Nikola Tesla conducted experiments on wireless transmission of electrical energy, but it was interrupted due to lack of funds. In the past few decades, a lot of attention has been focused on WPT, which is suitable for implantable medical devices, electric vehicle battery charging, household appliances and many other fields, showing a promising future way of power transmission.

[0003] The birth of this technology has brought great convenience to people's daily life. Its convenience lies in versatility, portability, safety, etc. The versatility not only makes electronic products free from the constraints of sockets and cables, but also solves the problem of incompatibility of electronic devices with different brands and different interfaces. Portability allows consumers to power electronic devices anytime and anywhere, and also solves the need for business travelers to carry a large number of power adapters. Safety can solve the electric sparks generated by contact and avoid fires that may be caused by electric sparks.

[0004] Since WPT has a short transmission distance and cannot solve the problem of medium-distance energy transmission, researchers have proposed magnetic resonance unlimited power transmission (MCR-WPT). MCR-WPT can achieve medium-distance energy transmission, but previous studies have found that there is a suitable distance between the transmitting coil and the receiving coil in the MCR-WPT system to maximize the transmission efficiency, and when the system's transmission efficiency reaches the maximum, it can only be at a specific transmission distance. If the transmission distance increases or decreases, the system's transmission efficiency will drop sharply, which will result in low practical application value. Therefore, certain technologies need to be adopted to enable the system to achieve high-efficiency transmission within a certain transmission range.

[0005] In the prior art, a multi-loop structure can solve the above problems, but this technology requires multiple switches, which makes the algorithm structure of controlling the switches complicated, and the switches also consume some energy. The circuit tuning method can also solve the above problems, but it will make the circuit structure very complicated and cannot be applied to different models. Summary of the invention

[0006] In view of this, in order to make up for the gaps and deficiencies in the prior art, the present invention provides an adaptive adjustment device and method for variable-distance wireless energy transmission, which can achieve high-efficiency transmission within a certain range. By moving the source coil or the load coil fixed on the guide rail in a two-dimensional plane, the coupling between the source coil and the transmitting coil, and the coupling between the load coil and the receiving coil are adjusted, so as to achieve high-efficiency transmission of the system at different transmission distances; the entire device does not require a switch to control, nor does it require a complex circuit structure, the system structure is simple and easy to implement; the cost is also relatively low; the source coil and the load coil can be adjusted separately or simultaneously, which increases the flexibility of the system.

[0007] It realizes high-efficiency transmission of electric energy at different transmission distances by offsetting the source coil and the transmitting coil and / or the load coil and the receiving coil by a certain distance. The device includes one or two guide rails (or other types of mechanisms that can achieve translation), a transmitting coil and a receiving coil, a source coil and a load coil; the source coil is fixed on the guide rail, and can be offset by adjusting a certain distance from the transmitting coil; the load coil is fixed on another guide rail, and can be offset by adjusting a certain distance from the receiving coil; the source coil and the load coil can adjust a certain offset distance at the same time or adjust the offset distance independently. The present invention can ensure high-efficiency energy transmission at different transmission distances, and can solve the problem that the transmission efficiency of traditional magnetic resonance wireless energy transmission decreases sharply as the transmission distance changes. It has high flexibility, and the two adjustment methods can be applied to different application scenarios, such as wireless charging of electric vehicles, wireless charging of logistics robots, or wireless charging devices for consumer electronic products, but is not limited to the above-mentioned applications.

[0008] The present invention specifically adopts the following technical solutions:

[0009] An adaptive adjustment device for variable distance wireless energy transmission, characterized in that it includes: a transmitting coil, a receiving coil, a source coil and a load coil; and a first adjustment device for adjusting the offset distance between the transmitting coil and the source coil and / or a second adjustment device for adjusting the offset distance between the receiving coil and the load coil.

[0010] Further, for the first adjustment device, the transmitting coil is a fixed end and the source coil is a movable end; for the second adjustment device, the receiving coil is a fixed end and the load coil is a movable end.

[0011] Furthermore, the first adjusting device and / or the second adjusting device adopts a guide rail.

[0012] Furthermore, the source coil and the transmitting coil are coupled, and the load coil and the receiving coil are coupled.

[0013] Furthermore, the transmitting coil, receiving coil, source coil and load coil are formed by winding metal wires or printing them on a dielectric substrate.

[0014] Furthermore, the transmitting coil and the receiving coil are arranged opposite to each other, the source coil is located above the guide rail of the first adjusting device, and the load coil is located below the guide rail of the second adjusting device.

[0015] And, an adaptive adjustment method applied to variable distance wireless energy transmission, characterized in that high-efficiency transmission of electric energy at different transmission distances is achieved by offsetting the source coil and the transmitting coil or the load coil and the receiving coil by a certain distance.

[0016] Furthermore, when the distance between the transmitting coil and the receiving coil changes, the offset distance of the source coil and / or the load coil is calculated, and the movement of the source coil and / or the load coil on the guide rail is adjusted according to the calculated offset distance to adjust the transmission efficiency.

[0017] Further, the following steps are included:

[0018] Step S1: adjusting the resonant frequency of the transmitting coil and the receiving coil by connecting capacitors of different capacitance values ​​in series;

[0019] Step S2: Obtain the distance between the transmitting coil and the receiving coil;

[0020] Step S3: calculating the offset distance through the functional relationship between the distance between the transmitting coil and the receiving coil and the offset distance of the source coil and / or the load coil;

[0021] Step S4: Control the movement of the source coil and / or the load coil on the guide rail by using the calculated offset distance.

[0022] Compared with the prior art, the present invention and its preferred solution can achieve high-efficiency transmission of the system at different transmission distances by moving the source coil (single-end adjustment) or by moving the offset distance of the source coil and the load coil (double-end adjustment) at the same time. The quantitative relationship between the moving distance and the transmission distance can be derived through equivalent circuit analysis. As long as the distance between the transmitting and receiving coils is calculated, the offset distance can be obtained, thereby achieving adaptive adjustment. The device does not require a switch or a complex circuit structure, and can improve the efficiency of the MCR-WPT system on the basis of a simple structure. In an example, compared with the traditional MCR-WPT system, the efficiency of moving the source coil alone is increased by nearly 40%, and the efficiency of moving the source coil and the load coil at the same time is increased by nearly 50%, and the manufacturing cost is also reduced; the device can be adjusted at a single end or at a double end, which reflects the flexibility of the system and can be applied in different practical scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0024] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention;

[0025] Figure 2 This is a three-dimensional schematic diagram of a single-end adjustment structure of Example 2 of the present invention;

[0026] Figure 3 This is a schematic diagram of the equivalent circuit principle of the coil structure of the fourth embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the working process of an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of a simulation model of an embodiment of the present invention;

[0029] Figure 6 A schematic diagram of a practical application scenario of an embodiment of the present invention;

[0030] In the figure: 1-series capacitor; 2-distance between transmitting coil and receiving coil; 3-terminal load; 4-load coil; 5-receiving coil; 6-first bias distance; 7-power supply; 8-source coil; 9-first guide rail; 10-transmitting coil; 11-second bias distance; 12-second guide rail. DETAILED DESCRIPTION

[0031] In order to make the features and advantages of this patent more obvious and easy to understand, two embodiments are specifically cited below for detailed description as follows:

[0032] like Figure 1 As shown, the adaptive adjustment device for variable distance wireless energy transmission provided by the first embodiment of the present invention includes: a transmitting coil 10, a receiving coil 5, a source coil 8 and a load coil 4. Among them, the transmitting coil 10 and the receiving coil 5 are respectively connected to a series capacitor 1, the load coil 4 is connected in series with a terminal load 3, and the source coil 8 is connected in series with a power supply 7. The spacing 2 between the transmitting coil and the receiving coil can change with the change of the application scenario, but for this embodiment, its value must be measurable, and can be completed by using an ultrasonic distance measuring device, a laser distance measuring device, a radar distance measuring device, etc. according to the specific application situation.

[0033] As the core design of this embodiment, a first guide rail 9 and a second guide rail 12 are provided. The source coil 8 is mounted on the first guide rail 9, and a first offset distance 6 between the source coil 8 and the transmitting coil 10 can be adjusted; correspondingly, the load coil 4 is mounted on the second guide rail 12, and a second offset distance 12 between the source coil 8 and the receiving coil 5 can be adjusted.

[0034] The first offset distance 6 and the second offset distance 12 may be physically equivalent. The dual-end adjustment scheme adopted in this embodiment is to control the actual offset distance by adjusting at either end, so as to facilitate use.

[0035] In a specific application scenario, the first offset distance 6 and the second offset distance 12 can be adjusted by an electrically controlled stepper motor, or by a combination of an encoder and a servo motor, and a single-chip microcomputer or a PLC is used as a controller to respond accurately after receiving the adjusted offset distance transmitted by the host computer.

[0036] In this embodiment, all coils are formed by winding metal wires or printing on a dielectric substrate. The dielectric sheet material used is FR4 sheet material, Rogers sheet material or Lianmao sheet material, but is not limited to the above materials. The shapes of all coils can be different. The source coil is composed of a single loop or a multi-loop loop, and the size can be adjusted according to actual conditions. The load coil is composed of a single loop or a multi-loop loop, and the size can be adjusted according to actual conditions.

[0037] like Figure 2 As shown, in the second embodiment of the present invention, considering that it may be inconvenient to adjust the offset distance of the receiving end, a single-end adjustment solution is proposed. Compared with the first embodiment, the second guide rail is cancelled, and only the source coil 8 is installed on the first guide rail 9, and the first offset distance 6 between the source coil 8 and the transmitting coil 10 can be adjusted. The use effect is generally the same as that of the first embodiment.

[0038] The theoretical core of the above design is that in the MCR-WPT system, the offset distance (d) and the transmission distance (d 23 ) can be represented by a function: d = F(d 23 ). The following is a single-ended regulation example (such as Figure 2 As shown), a method is given to derive the expression of this function, but it is not limited to this method for derivation.

[0039] The equivalent circuit diagram of the system is as follows Figure 3 As shown, each coil consists of R i L i C i (i=1-4) lumped parameters are used instead and the cross coupling between coils far away is ignored, that is, K 13 =K 14 =K 24 =0. K 12 , K 23 , K 34 It is used to represent the coupling coefficient between each adjacent coil; M 12 , M 23 , M 34It is used to represent the mutual inductance between each adjacent coil; the quality factor of each coil is represented by Q1, Q2, Q3, Q4, and ω0 represents the resonant frequency of the transmitting coil and the receiving coil. R1 is the equivalent resistance of the source coil, and R4 is the equivalent resistance of the load coil, and its resistance value is very small; R S and R L The matching resistors of the transmitting end and the receiving end are 50Ω in this device, but it is not limited to this value. Therefore, R1<<R S , R4<<R L From the above equivalent circuit diagram, we can get the matrix relationship between the input voltage and the current on each coil;

[0040]

[0041] in

[0042] The impedance of the source coil port is Combining (1) we can get:

[0043]

[0044] In order to achieve high efficiency transmission, Z IN Must match R S , we can get the matching condition (3):

[0045]

[0046] (3) can be further written as:

[0047]

[0048] From (4), we can observe that when the transmission distance d 23 When it increases, it corresponds to K 23 will decrease. In order to satisfy condition (4), K must be reduced. 12 or K 34 Therefore, K can be reduced by moving the source coil alone by a distance d. 12 , or by moving both the source coil and the load coil to reduce K simultaneously 12 and K 34 Through theoretical derivation, the distance d between the transmitting coil and the receiving coil can be established. 23 A functional relationship between the offset distance d and the source coil is different for moving the source coil alone and moving the source coil and the load coil at the same time, which can be expressed as a function:

[0049] d=F(d 23 ) (5);

[0050] From (5), we can conclude that d 23In order to ensure efficient energy transmission when changing, the offset distance d should be used between the coils. Figure 4 As shown, based on the above theoretical analysis, this embodiment obtains a control method for the device, that is: when the distance between the transmitting coil and the receiving coil changes, the offset distance of the source coil and / or the load coil is calculated, and the movement of the source coil and / or the load coil on the guide rail is adjusted according to the calculated offset distance to adjust the transmission efficiency.

[0051] The specific steps include:

[0052] Step S1: adjusting the resonant frequency of the transmitting coil and the receiving coil by connecting capacitors of different capacitance values ​​in series;

[0053] Step S2: Obtain the distance between the transmitting coil and the receiving coil;

[0054] Step S3: calculating the offset distance through the functional relationship between the distance between the transmitting coil and the receiving coil and the offset distance of the source coil and / or the load coil;

[0055] Step S4: Control the movement of the source coil and / or the load coil on the guide rail by using the calculated offset distance.

[0056] The devices used in the measurement and control process of the above steps are not limited and can be designed using any mature existing solutions.

[0057] like Figure 5 As shown, this embodiment provides an example of system model design; Figure 6 As shown, this embodiment also provides an application example of the system in an actual scenario. Obviously, in the application example of wireless charging of electric vehicles, it is more appropriate to adopt a single-ended regulation solution.

[0058] This patent is not limited to the above-mentioned optimal implementation mode. Anyone can derive other forms of adaptive adjustment devices and methods for variable-distance wireless energy transmission under the inspiration of this patent. All equal changes and modifications made according to the scope of the patent application of the present invention should be covered by this patent.

Claims

1. An adaptive adjustment method for variable distance wireless energy transmission, characterized in that: include: a transmitting coil, a receiving coil, a source coil, and a loading coil; and a first adjustment device for adjusting the offset distance between the transmitting coil and the source coil and / or a second adjustment device for adjusting the offset distance between the receiving coil and the load coil; The first adjusting device and / or the second adjusting device adopts a guide rail; By moving a source coil or a load coil fixed on a guide rail in a two-dimensional plane, the source coil and the transmitting coil and / or the load coil and the receiving coil are offset by a certain distance to achieve high-efficiency transmission of electric energy at different transmission distances; When the distance between the transmitting coil and the receiving coil changes, the offset distance of the source coil and / or the load coil is calculated, and the movement of the source coil and / or the load coil on the guide rail is adjusted according to the calculated offset distance to adjust the transmission efficiency; The adaptive adjustment method includes the following steps: Step S1: adjusting the resonant frequency of the transmitting coil and the receiving coil by connecting capacitors of different capacitance values ​​in series; Step S2: Obtain the distance between the transmitting coil and the receiving coil; Step S3: calculating the offset distance through the functional relationship between the distance between the transmitting coil and the receiving coil and the offset distance of the source coil and / or the load coil; Step S4: Control the movement of the source coil and / or the load coil on the guide rail by using the calculated offset distance.

2. The adaptive adjustment method for variable distance wireless energy transmission according to claim 1, characterized in that: For the first adjustment device, the transmitting coil is a fixed end and the source coil is a movable end; for the second adjustment device, the receiving coil is a fixed end and the load coil is a movable end.

3. The adaptive adjustment method for variable distance wireless energy transmission according to claim 1, characterized in that: The source coil is coupled to the transmitting coil, and the load coil is coupled to the receiving coil.

4. The adaptive adjustment method for variable distance wireless energy transmission according to claim 1, characterized in that: The transmitting coil, receiving coil, source coil and load coil are formed by winding metal wires or printing them on a dielectric substrate.

5. The adaptive adjustment method for variable distance wireless energy transmission according to claim 2, characterized in that: The transmitting coil and the receiving coil are arranged opposite to each other, the source coil is located above the guide rail of the first adjusting device, and the load coil is located below the guide rail of the second adjusting device.

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