A three-layer composite wireless charging optimized coupler that can achieve efficient energy transfer and has high anti-offset ability

Abstract

The present invention discloses a three - layer composite wireless charging optimized coupler that can achieve efficient energy transmission and has high anti - offset ability, which includes an upper - layer coil, a middle - layer coil, and a lower - layer coil that are stacked in sequence from top to bottom and connected in series. The upper - layer coil is connected to a power supply module, and the lower - layer coil is connected to a transmitting - end compensation capacitor; the middle - layer coil includes four isosceles right - angled triangles of the same size, and the four isosceles right - angled triangles of the same size are spliced with the right - angle as the center point to form a square, and four groups of right - angled sides form a central cross region; the lower - layer coil is a compensation coil for the central cross region of the middle - layer coil, and horizontally wraps the central cross region of the middle - layer coil; the upper - layer coil is a compensation coil for the central square region of the lower - layer coil, and the upper - layer coil horizontally wraps the central square region of the lower - layer coil. The optimized coupler of the present invention is applied in a wireless charging system, achieving optimized improvements in multiple objectives such as high transmission efficiency and high anti - offset characteristics.

Description

Technical Field

[0001] The present invention relates to wireless power transfer technology, and more particularly to a three-layer composite wireless charging optimized coupler that can achieve efficient energy transfer and has high anti-offset ability. Background Art

[0002] Wireless charging technology is a transmission method that converts electrical energy into other forms of relay energy through a transmitter, transmits it over a certain distance in the air, and then converts the relay energy into electrical energy through a receiver to achieve wireless power transfer. Generally, in order to ensure the effective transmission of electrical energy, it is necessary to ensure that the transmitting coil and the receiving coil are directly opposite. However, in actual applications, due to environmental impacts, user operations, etc., the coils will inevitably deviate to a certain extent, which will lead to a reduction in transmission efficiency and make the system unable to transmit energy stably. In order to ensure that the system can still maintain a high transmission efficiency under non-ideal conditions, it is necessary to study the deviation tolerance of the coils.

[0003] Regarding the problem of improving the deviation tolerance, the usual solution is to solve it from the aspect of circuit structure topology, study the resonant network topology structure, add a matching circuit, improve the efficiency of the system, and reduce deviation interference. However, this complex circuit design will increase system losses. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to provide a three-layer composite wireless charging optimized coupler that can achieve efficient energy transfer and has high anti-offset ability. By improving the coupler structure, it is possible to simultaneously improve both the high anti-offset ability and the high transmission efficiency.

[0005] Technical Solution: A three-layer composite wireless charging optimized coupler of the present invention that can achieve efficient energy transfer and has high anti-offset ability includes an upper coil, a middle coil, and a lower coil stacked in sequence from top to bottom. The upper coil, the middle coil, and the lower coil are connected in series in sequence. The upper coil is connected to a power supply module, and the lower coil is connected to a transmitting-end compensation capacitor. The middle coil includes four isosceles right triangles of the same size, namely the first isosceles right triangle, the second isosceles right triangle, the third isosceles right triangle, and the fourth isosceles right triangle. The four isosceles right triangles of the same size are spliced with the right angle as the center point to form a square, and the right-angle sides of the four isosceles right triangles of the same size form a central cross region. The lower coil is a compensation coil for the central cross region of the middle coil, and the lower coil wraps the central cross region of the middle coil in the horizontal direction. The upper coil is a compensation coil for the central square region of the lower coil, and the upper coil wraps the central square region of the lower coil in the horizontal direction.

[0006] Optionally, it is specified that the right angle of the first isosceles right triangle faces downward in the page, the hypotenuse is above the right angle, the side to the left of the right angle of the first isosceles right triangle is denoted as the first right side, the side to the right is denoted as the second right side, and the four isosceles right triangles forming the square region are respectively the first isosceles right triangle, the second isosceles right triangle, the third isosceles right triangle, and the fourth isosceles right triangle in the clockwise direction;

[0007] The winding method of the middle layer coil is as follows: starting from the first right side of the first right triangle, from the first right side of the first right triangle to the second right side of the first right triangle, to the first right side of the second right triangle, to the second right side of the second right triangle, to the first right side of the third right triangle, to the second right side of the third right triangle, to the first right side of the fourth right triangle, to the second right side of the fourth right triangle. At this time, the internal cross winding is completed, and then it is connected to the hypotenuse of the fourth right triangle, then to the hypotenuse of the third right triangle, then to the hypotenuse of the second right triangle, then to the hypotenuse of the first right triangle. The hypotenuse of the first right triangle is not connected to the first right side of the first right triangle, and they are respectively used to connect in series with the upper layer coil and the lower layer coil.

[0008] Optionally, the current of the middle layer coil flows along the winding wire, and the first, second, third, and fourth isosceles right triangle regions respectively form a first current loop, a second current loop, a third current loop, and a fourth current loop. The current flow directions of these four current loops are all counterclockwise.

[0009] Optionally, denote the lower coil segment along the first right-angled side of the first isosceles right triangle in the inner direction of the first isosceles right triangle as the thirteenth segment of the lower coil, the lower coil segment along the second right-angled side of the first isosceles right triangle in the inner direction of the first isosceles right triangle as the twenty-fourth segment of the lower coil, the lower coil segment along the first right-angled side of the second isosceles right triangle in the inner direction of the second isosceles right triangle as the twenty-second segment of the lower coil, the lower coil segment along the second right-angled side of the second isosceles right triangle in the inner direction of the second isosceles right triangle as the twenty-first segment of the lower coil, the lower coil segment along the first right-angled side of the third isosceles right triangle in the inner direction of the third isosceles right triangle as the nineteenth segment of the lower coil, the lower coil segment along the second right-angled side of the third isosceles right triangle in the inner direction of the third isosceles right triangle as the eighteenth segment of the lower coil, the lower coil segment along the first right-angled side of the fourth isosceles right triangle in the inner direction of the fourth isosceles right triangle as the sixteenth segment of the lower coil, the lower coil segment along the second right-angled side of the fourth isosceles right triangle in the inner direction of the fourth isosceles right triangle as the fifteenth segment of the lower coil, the lower coil segment connecting the thirteenth segment and the fifteenth segment of the lower coil as the fourteenth segment of the lower coil, the lower coil segment connecting the twenty-second segment and the twenty-fourth segment of the lower coil as the twenty-third segment of the lower coil, the lower coil segment connecting the nineteenth segment and the twenty-first segment of the lower coil as the twentieth segment of the lower coil, and the lower coil segment connecting the sixteenth segment and the eighteenth segment of the lower coil as the seventeenth segment of the lower coil;

[0010] The winding method of the lower coil is as follows: in the horizontal direction, the lower coil is wound closely along the inner diameter of the right-angled side of the isosceles right triangle area of the middle coil, and the number of turns is increased in the inner direction of the right-angled triangle; the fourteenth segment, the fifteenth segment, the sixteenth segment, the seventeenth segment, the eighteenth segment, the nineteenth segment, the twentieth segment, the twenty-first segment, the twenty-second segment, the twenty-third segment, the twenty-fourth segment, and the thirteenth segment of the lower coil are wound in sequence in the counterclockwise direction. The fourteenth segment and the thirteenth segment of the lower coil are not connected, and are respectively connected in series with the middle coil and the transmitting-end compensation capacitor C T ; the fourteenth segment of the lower coil is connected to the hypotenuse of the first isosceles right triangle of the middle coil, and the thirteenth segment of the lower coil is connected to the transmitting-end compensation capacitor C T .

[0011] Optionally, the current of the lower coil flows along the winding wire, and the overall area of the lower coil forms a fifth current loop in the counterclockwise direction.

[0012] Optionally, mark the intersection of the thirteenth segment and the twenty-fourth segment of the lower-layer coil as point A, the intersection of the twenty-first segment and the twenty-second segment of the lower-layer coil as point B, the intersection of the eighteenth segment and the nineteenth segment of the lower-layer coil as point C, and the intersection of the fifteenth segment and the sixteenth segment of the lower-layer coil as point D. At the corresponding positions of points A, B, C, and D on the upper-layer coil, set points E, F, G, and H respectively. The coil segment formed by connecting point E to point H is the twenty-sixth segment of the upper-layer coil, the coil segment formed by connecting point H to point G is the twentieth segment of the upper-layer coil, the coil segment formed by connecting point G to point F is the twenty-eighth segment of the upper-layer coil, and the coil segment formed by connecting point F to point E is the twenty-fifth segment of the upper-layer coil;

[0013] The winding method of the upper-layer coil is as follows: in the horizontal direction, the number of turns of the upper-layer coil expands from the inside to the outside; wind the twenty-sixth segment, the twenty-seventh segment, the twenty-eighth segment, and the twenty-fifth segment of the upper-layer coil in the counterclockwise direction respectively. The twenty-sixth segment and the twenty-fifth segment of the upper-layer coil are not connected and are respectively used to connect in series with the middle-layer coil and the power supply module; the twenty-fifth segment of the upper-layer coil is connected to the first right-angled side of the first isosceles right triangle of the middle-layer coil, and the twenty-sixth segment of the upper-layer coil is connected to the power supply module.

[0014] Optionally, the current of the upper-layer coil flows along the winding wire, and the overall area of the upper-layer coil forms a sixth current loop in the counterclockwise direction.

[0015] Optionally, the overall current of the optimized coupler is emitted from the power supply module, flows from the sixth current loop of the upper-layer coil to the first current loop of the first isosceles right triangle of the middle-layer coil, flows to the second current loop of the second isosceles right triangle, flows to the third current loop of the third isosceles right triangle, flows to the fourth current loop of the fourth isosceles right triangle, flows to the fifth current loop of the lower-layer coil, and flows out to the transmitting-end compensation capacitor. The overall current of the optimized coupler flows in the counterclockwise direction.

[0016] Optionally, there is a certain proportional relationship among the number of turns of the upper, middle, and lower coils of the optimized coupler. Specifically:

[0017] Denote the wire diameter of a single wire as d, the independent variable x as the change in the number of turns of the corresponding coil, and the number of turns of the middle-layer coil as N2. Then the magnetic field strength in the central region of the isosceles right triangle coil is:

[0018]

[0019] where D is the distance from a point in space to the wire, A = μ0I / 4π, μ0 is the permeability of free space, and I is the magnitude of the current flowing through the wire;

[0020] Denote the number of turns of the lower-layer coil as N3. Then, the magnetic field strength at the center of the central cross region of the middle-layer coil under the compensation of the lower-layer coil is:

[0021]

[0022] Denote the number of turns of the upper-layer coil as N1. Then, the magnetic field strength at the center of the central square region of the middle-layer coil under the compensation of the upper-layer coil is:

[0023]

[0024] To ensure that the magnetic field strength remains stable within the coverage area of the optimized coupler, it is necessary to satisfy B Pcoil1 = B Pcoil2 = B Pcoil3 . When the number of turns N2 of the middle-layer coil is determined, the number of turns N1 and N3 of the upper and lower-layer coils are also determined synchronously.

[0025] A wireless charging system according to the present invention, wherein the transmitting coil at the transmitting end and the receiving coil at the receiving end of the system both adopt the above-mentioned optimized coupler, and the upper-layer coils of the receiving coil and the transmitting coil are arranged opposite to each other. The transmitting coil and the receiving coil are mutually inductively coupled to realize the transmission of electric energy between the transmitting end and the receiving end.

[0026] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows:

[0027] (1) The optimized coupler is formed by stacking and winding three layers of coils. The overall coil structure is symmetrical, and the copper loss is small. The circuit resonance network adopts a series topology resonance network, and the system loss is small. Moreover, by redesigning the coil structure, the magnetic field strength between the coils is increased, enabling the overall electric energy transmission to take into account both high transmission efficiency and high anti-offset characteristics;

[0028] (2) The power supply device and the electrical device of the wireless charging system adopted by the present invention transfer energy through an electromagnetic field, without the need for direct physical contact, which can effectively cope with the influence of bad weather, humid environment, etc. on the load charging, and the power supply reliability is relatively high. Description of the Drawings

[0029] Figure 1 It is a schematic circuit structure diagram of a wireless charging system that realizes high efficiency and high deviation tolerance provided by an embodiment of the present invention;

[0030] Figure 2 It is a schematic structural diagram of a three-layer composite wireless charging optimized coupler that can achieve high-efficiency energy transmission and has high anti-offset ability provided by an embodiment of the present invention;

[0031] Figure 3Schematic diagram of the structure disassembly and winding sequence description of a three - layer composite wireless charging optimized coupler with high - efficiency energy transfer and high anti - offset ability provided by an embodiment of the present invention;

[0032] Figure 4 Magnetic field contour map caused by the middle - layer coil of the optimized coupler provided by an embodiment of the present invention;

[0033] Figure 5 Magnetic field contour map caused by the lower - layer coil and the middle - layer coil of the optimized coupler provided by an embodiment of the present invention;

[0034] Figure 6 Magnetic field contour map caused by the overall optimized coupler provided by an embodiment of the present invention;

[0035] Figure 7 Experimental prototype of the optimized coupler provided by an embodiment of the present invention;

[0036] Figure 8 Comparison schematic diagram between the optimized coupler provided by an embodiment of the present invention and DD coils and square coils;

[0037] Figure 9 Graph of the change in transmission efficiency of the optimized coupler provided by an embodiment of the present invention compared with DD coils and square coils during longitudinal offset;

[0038] Figure 10 Graph of the change in transmission efficiency and the amplitude of efficiency change of the optimized coupler provided by an embodiment of the present invention compared with DD coils and square coils during lateral offset. Detailed implementation manners

[0039] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are only for illustrative purposes and should not be construed as limiting the present invention; for better illustration of this embodiment, some components in the drawings are omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well - known structures and their descriptions in the drawings may be omitted.

[0040] To solve the problems of the prior art, the present invention starts from the design of the coil shape and realizes coil decoupling by optimizing the coupler structure to reduce consumption.

[0041] As Figure 1 shown, a wireless charging system of the present invention includes a DC power supply, a high - frequency full - bridge inverter circuit, a transmitting end, a receiving end, a rectifying circuit, and a load charging circuit. The transmitting end includes a transmitting coil L T and a transmitting compensation topology, and the receiving end includes a receiving coil L Rand the receiving compensation topology. The DC power supply is used to provide electrical energy for the entire system. The high-frequency full-bridge inverter circuit is used to invert the DC power into high-frequency alternating current of a specified frequency and input it to the transmitting end. The transmitting coil and the receiving coil are mutually inductively coupled to realize the transmission of electrical energy between the transmitting end and the receiving end. The electrical energy received at the receiving end is rectified into DC power by the rectifier circuit and then flows into the load charging circuit to supply power to the load, completing the wireless charging operation.

[0042] The DC power supply, the high-frequency full-bridge inverter circuit, and the drive circuit together constitute the power module of the system. The drive circuit is used to generate a PWM signal and convert it into a MOSFET drive signal to drive the high-frequency full-bridge inverter circuit to invert the DC power input from the DC power supply into alternating current of a specified frequency, providing electrical energy for the system.

[0043] The transmitting coil L T and the receiving coil L R have the same structure, both adopting the wireless charging optimized coupler structure designed by the present invention with high transmission efficiency and high deviation tolerance, as Figure 2 shown. The optimized coupler includes three parts: the upper-layer coil, the middle-layer coil, and the lower-layer coil, which are connected in series from top to bottom to form the overall structure of the charging system optimized coupler. The upper-layer coils of the transmitting coil L T and the receiving coil L R are arranged oppositely, that is, for the transmitting coil L T the lowermost is the upper-layer coil, the middle is the middle-layer coil, and the uppermost is the lower-layer coil; for the receiving coil L R the lowermost is the lower-layer coil, the middle is the middle-layer coil, and the uppermost is the upper-layer coil.

[0044] For the parameters of the transmitting coil L T , the receiving coil L R , the compensation capacitor C of the transmitting coil T , the compensation capacitor C of the receiving coil R , the resonant frequencies of the primary and secondary resonant loops are:

[0045]

[0046] The transmitting coil resonant network and the receiving coil resonant network form an S-S topology, which has the advantages of high power transmission and high deviation tolerance. The transmission efficiency η of the wireless charging system is:

[0047]

[0048] where U S is the AC input voltage, N T and N R represent the number of turns of the transmitting coil and the receiving coil respectively, ω is the resonant angular frequency, B T and B Rrespectively represent the magnetic field intensity generated by a single turn at the centers of the transmitting coil and the receiving coil perpendicular to the winding plane. S1 and S2 are the total coil areas of the transmitting coil and the receiving coil respectively, and R T and R R respectively represent the internal resistances of the transmitting-end circuit and the receiving-coil circuit, and R is the resistive output load.

[0049] When other parameters are the same, the larger the value of the magnetic field intensity B, the greater the transmission efficiency of the system. At the same time, the more stable the magnetic field intensity B, the stronger the deviation tolerance ability of the system.

[0050] According to Biot-Savart's law, the magnetic induction intensity generated by a wire at a point P in space is:

[0051]

[0052] where D is the distance from a point in space to the wire, μ0 is the magnetic permeability of vacuum, θ1 and θ2 are the angles between P and the two endpoints of the wire respectively, and I is the magnitude of the current flowing through the wire.

[0053] To increase the magnetic field intensity between coils, the coil structure needs to be redesigned. For a rectangular coil, the magnitude of the magnetic induction intensity generated by the coil at a point P in the Z-axis direction can be expressed as the sum of the magnetic induction intensities generated by each of the four sides at point P. That is, the magnetic field intensity of the rectangular coil in space at point P is:

[0054]

[0055] where A = μ0I / 4π, which is a constant value when the system configuration is determined. The angles between P and the endpoints of the four wires are θ1, θ2, π / 2 - θ1, π / 2 - θ3, θ3, θ4, π / 2 - θ2, π / 2 - θ4 respectively, and the distances from P to the respective wires are D1, D2, D3, D4. When P is at the center point of the enclosed rectangular area, D1 = D3, D2 = D4, and θ1 = θ2 = θ3 = θ4, denoted as θ. That is, the angles between P and each endpoint are equal. Then formula (4) can be rewritten as:

[0056]

[0057] Denote the distance from P to the endpoint as l, then formula (5) can be simplified to:

[0058]

[0059] When θ = 45°, that is, when the four wires form a square coil, the magnetic field intensity reaches the maximum value.

[0060] On this basis, when connecting the diagonals of the square coil and dividing the square coil into four isosceles right triangle coils, due to the characteristics of the triangle itself, its center point is the intersection of the angle bisectors and is equidistant from the three sides. Denote the distance between point P and the three sides as D, then the magnitude of the magnetic field strength in the central region of the isosceles right triangle is:

[0061]

[0062] And the magnetic field strength of this region within the square coil region is:

[0063]

[0064] It can be seen that using the splicing method of isosceles right triangles will enhance the magnetic field strength in the central region of the isosceles right triangle. However, at the same time, the magnetic field strength at the right-angled sides of the isosceles right triangle will gradually approach 0, which also leads to a large change in the magnetic field strength within the square region spliced by isosceles right triangles. To increase the magnetic field strength in this region, a compensation coil needs to be wound around the right-angled sides of the isosceles right triangle.

[0065] Since the square region is spliced by the right-angled sides of the isosceles right triangle coils, the shape of the compensation coil should be similar to a hollow cross. It should be noted that when P is in the corner region of the compensation coil, the magnetic field strength is mainly provided by the adjacent wires, while when P is in the central region, the distance from each side is relatively large, and the obtained magnetic field strength is relatively small. To compensate for the magnetic field strength in this section of the region, a square coil covering the central region needs to be added above the coil.

[0066] Denote the wire diameter of a single wire as d, the independent variable x as the change in the number of turns of the corresponding coil, and the number of turns of the middle-layer coil as N2. Then the magnetic field strength in the central region of the right triangle coil is:

[0067]

[0068] Denote the number of turns of the lower-layer coil as N3. Then the central magnetic field strength in the central cross region of the middle-layer coil under the compensation of the lower-layer coil is:

[0069]

[0070] Denote the number of turns of the upper-layer coil as N1. Then the central magnetic field strength in the central square region of the middle-layer coil (corresponding to the central square region of the lower-layer coil) under the compensation of the upper-layer coil is:

[0071]

[0072] To ensure that the magnetic field strength remains stable within the coverage area of the optimized coupler, it is necessary to satisfy B Pcoil1 = B Pcoil2= B Pcoil3 When the number of turns N2 of the middle layer coil is determined, the number of turns N1 and N3 of the upper and lower layer coils can also be determined synchronously.

[0073] The designed optimized coupler can be divided into three parts: the upper layer coil, the middle layer coil and the lower layer coil from the spatial structure. All three are wound with Litz wire and connected in series.

[0074] The designed optimized coupler has a three-layer structure. The middle layer coil is the main coil of the optimized coupler and is composed of four isosceles right-angled triangle coils with the same current direction and the same size spliced along the right-angled sides. As shown in Figure 3 (a) in, it can increase the magnitude of the magnetic induction intensity in the central region of the four isosceles right-angled triangles to a certain extent. However, since the current flowing through the opposing coils weakens the magnetic field in the region of the right-angled sides of the isosceles right-angled triangles (as shown in Figure 4 ), the lower layer coil is a hollow cross structure that horizontally wraps the cross region formed by the right-angled sides of the isosceles right-angled triangles in the middle layer coil. As shown in Figure 3 (b) in, it converges the magnetic induction lines in the internal cross region and enhances the magnetic induction intensity. However, since the central region is too far from the compensation coil wire, the compensation effect received is relatively weak, as shown in Figure 5 ; The upper layer coil is a square coil that horizontally wraps the central hollow region of the lower layer coil. As shown in Figure 3 (c) in, it increases the central magnetic field intensity, as shown in Figure 6 . The lower layer coil serves as the compensation coil for the cross region of the middle layer coil, and the upper layer coil serves as the compensation coil for the central region of the lower layer coil. Finally, an optimized wireless charging coupler that can achieve high efficiency and high deviation tolerance is designed.

[0075] As shown in Figure 3 (a) in, it is stipulated that the right angle of the isosceles right-angled triangle faces downward on the page, the hypotenuse is above the right angle, the left right-angled side of the right angle is marked as side 1, and the right right-angled side is marked as side 2. The four isosceles right-angled triangles that make up the square region are respectively the first isosceles right-angled triangle ①, the second isosceles right-angled triangle ②, the third isosceles right-angled triangle ③ and the fourth isosceles right-angled triangle ④ in the clockwise direction.

[0076] The winding method of the designed optimized coupler is as shown in Figure 3As shown in (a), (b), and (c), it is wound in the order of the labels. First, the middle layer coil is wound, then the lower layer coil is wound in series, and finally the upper layer coil is wound in series. Among them, when winding the middle layer coil: First, it is connected to the upper layer coil, and then, in a clockwise direction, the two right-angled sides of the first isosceles right triangle, the two right-angled sides of the second isosceles right triangle, the two right-angled sides of the third isosceles right triangle, and the two right-angled sides of the fourth isosceles right triangle are wound in sequence. Then, the hypotenuse of the fourth isosceles right triangle, the hypotenuse of the third isosceles right triangle, the hypotenuse of the second isosceles right triangle, and the hypotenuse of the first isosceles right triangle are wound. Then, it is connected to the lower layer coil. When winding the lower layer coil: In the horizontal direction, the lower layer coil is wound closely along the inner diameter of the right-angled side of the right-angled triangle area of the middle layer coil, the number of turns is increased along the direction inside the right-angled triangle, and each section of the lower layer coil is wound in a counterclockwise direction. Then, it is connected to the transmitting end compensation capacitor. When winding the upper layer coil: First, it is connected to the power supply module, and then, in the horizontal direction, the number of turns of the upper layer coil expands from the inside to the outside, and each section of the upper layer coil is wound in a counterclockwise direction. Then, it is connected to the middle layer coil.

[0077] As Figure 3 As shown in (a), the winding method of the middle layer coil is: Starting from the first right-angled side 1 of the first isosceles right triangle ①, from the first right-angled side 1 of the first isosceles right triangle ① to the second right-angled side 2 of the first isosceles right triangle ①, to the first right-angled side 3 of the second isosceles right triangle ②, to the second right-angled side 4 of the second isosceles right triangle ②, to the first right-angled side 5 of the third isosceles right triangle ③, to the second right-angled side 6 of the third isosceles right triangle ③, to the first right-angled side 7 of the fourth isosceles right triangle ④, to the second right-angled side 8 of the fourth isosceles right triangle ④. At this time, the internal cross winding is completed. Then, it is connected to the hypotenuse 9 of the fourth isosceles right triangle, then to the hypotenuse 10 of the third isosceles right triangle, then to the hypotenuse 11 of the second isosceles right triangle, and then to the hypotenuse 12 of the first isosceles right triangle. The hypotenuse 12 of the first isosceles right triangle ① is not connected to the first right-angled side 1 of the first isosceles right triangle ①, and they are respectively used to connect the upper layer coil and the lower layer coil in series.

[0078] As Figure 3As shown in (b), the lower-layer coil is a compensation coil for the central cross region of the middle-layer coil of the optimized coupler. In the horizontal direction, the upper and lower-layer coils wrap the central cross region of the middle-layer coil. Denote the lower-layer coil segment of the first right-angled side 1 of the first isosceles right triangle ① along the inner direction of the first isosceles right triangle ① as the 13th segment 13 of the lower-layer coil, and the lower-layer coil segment of the second right-angled side 2 of the first isosceles right triangle ① along the inner direction of the first isosceles right triangle ① as the 24th segment 24 of the lower-layer coil. Denote the lower-layer coil segment of the first right-angled side 3 of the second isosceles right triangle ② along the inner direction of the second isosceles right triangle ② as the 22nd segment 22 of the lower-layer coil, and the lower-layer coil segment of the second right-angled side 4 of the second isosceles right triangle ② along the inner direction of the second isosceles right triangle ② as the 21st segment 21 of the lower-layer coil. Denote the lower-layer coil segment of the first right-angled side 5 of the third isosceles right triangle ③ along the inner direction of the third isosceles right triangle ③ as the 19th segment 19 of the lower-layer coil, and the lower-layer coil segment of the second right-angled side 6 of the third isosceles right triangle ③ along the inner direction of the third isosceles right triangle ③ as the 18th segment 18 of the lower-layer coil. Denote the lower-layer coil segment of the first right-angled side 7 of the fourth isosceles right triangle ④ along the inner direction of the fourth isosceles right triangle ④ as the 16th segment 16 of the lower-layer coil, and the lower-layer coil segment of the second right-angled side 8 of the fourth isosceles right triangle ④ along the inner direction of the fourth isosceles right triangle ④ as the 15th segment 15 of the lower-layer coil. The lower-layer coil segment connecting the 13th segment 13 and the 15th segment 15 of the lower-layer coil is the 14th segment 14 of the lower-layer coil. The lower-layer coil segment connecting the 22nd segment 22 and the 24th segment 24 of the lower-layer coil is the 23rd segment 23 of the lower-layer coil. The lower-layer coil segment connecting the 19th segment 19 and the 21st segment 21 of the lower-layer coil is the 20th segment 20 of the lower-layer coil. The lower-layer coil segment connecting the 16th segment 16 and the 18th segment 18 of the lower-layer coil is the 17th segment 17 of the lower-layer coil.

[0079] The winding method of the lower-layer coil is as follows: In the horizontal direction, the lower-layer coil is wound closely along the inner diameter of the right-angled side of the isosceles right triangle region of the middle-layer coil, and the number of turns is increased along the inner direction of the isosceles right triangle. The 14th segment 14, the 15th segment 15, the 16th segment 16, the 17th segment 17, the 18th segment 18, the 19th segment 19, the 20th segment 20, the 21st segment 21, the 22nd segment 22, the 23rd segment 23, the 24th segment 24, and the 13th segment 13 of the lower-layer coil are wound in sequence in the counterclockwise direction. The 14th segment 14 of the lower-layer coil is not connected to the 13th segment 13 of the lower-layer coil, and they are respectively connected in series with the middle-layer coil and the transmitting-end compensation capacitor C TThe fourteenth section 14 of the lower - layer coil is connected to the hypotenuse 12 of the first isosceles right - triangle ① of the middle - layer coil, and the thirteenth section 13 of the lower - layer coil is connected to the transmitting - end compensation capacitor C T 。

[0080] As Figure 3 shown in (c) of the figure, the upper - layer coil is a compensation coil for the central square area of the lower - layer coil of the optimized coupler. Horizontally, the upper - layer coil wraps the central square area of the lower - layer coil. Denote the intersection of the thirteenth section 13 and the twenty - fourth section 24 of the lower - layer coil as point A, the intersection of the twenty - first section 21 and the twenty - second section 22 of the lower - layer coil as point B, the intersection of the eighteenth section 18 and the nineteenth section 19 of the lower - layer coil as point C, and the intersection of the fifteenth section 15 and the sixteenth section 16 of the lower - layer coil as point D. Points E, F, G, and H are respectively set at the corresponding positions of the upper - layer coil. The coil section formed by connecting point E to point H is the twenty - sixth section 26 of the upper - layer coil, the coil section formed by connecting point H to point G is the twenty - seventh section 27 of the upper - layer coil, the coil section formed by connecting point G to point F is the twenty - eighth section 28 of the upper - layer coil, and the coil section formed by connecting point F to point E is the twenty - fifth section 25 of the upper - layer coil.

[0081] The winding method of the upper - layer coil is as follows: Horizontally, the number of turns of the upper - layer coil expands from the inside to the outside. The twenty - sixth section 26, the twenty - seventh section 27, the twenty - eighth section 28, and the twenty - fifth section 25 of the upper - layer coil are respectively wound in the counter - clockwise direction. The twenty - sixth section 26 and the twenty - fifth section 25 of the upper - layer coil are not connected, and are respectively used to connect in series with the middle - layer coil and the power - supply module. The twenty - fifth section 25 of the upper - layer coil is connected to the first right - angle side 1 of the first isosceles right - triangle ① of the middle - layer coil. The twenty - sixth section 26 of the upper - layer coil is connected to the power - supply module.

[0082] The optimized coupler is powered by one - way power supply, and the power - supply interfaces are respectively Figure 3 the branch 1 and the branch 28 in (a), (b), and (c) of the figure. The current flows in sequence along the branch 1 - 28. The branches 1, 2, 12; 3, 4, 11; 6, 10, 5; 8, 9, 7; 13 - 24; 25 - 28 respectively form counter - clockwise current loops. The current directions formed after the three - layer coils are connected in series and superimposed are the same, as Figure 3 shown in (a), (b), and (c) of the figure.

[0083] The current in the middle layer coil of the optimized coupler flows along the winding wire. The first isosceles right triangle ①, the second isosceles right triangle ②, the third isosceles right triangle ③, and the fourth isosceles right triangle ④ regions respectively form the first current loop, the second current loop, the third current loop, and the fourth current loop. The current flow directions of these four current loops are all counterclockwise. The current in the lower layer coil flows along the winding wire, and the overall region of the lower layer coil forms a fifth current loop in the counterclockwise direction. The current in the upper layer coil flows along the winding wire, and the overall region of the upper layer coil forms a sixth current loop in the counterclockwise direction.

[0084] The overall current of the optimized coupler is emitted from the power supply module, flows from the sixth current loop to the first current loop, then to the second current loop, then to the third current loop, then to the fourth current loop, then to the fifth current loop, and finally flows out to the transmitting end compensation capacitor C. T The overall current of the optimized coupler flows in the counterclockwise direction.

[0085] In this embodiment, the optimized coupler is composed of three layers of 5-mm-thick coils spliced together. The outer diameter of the upper layer coil is 120 mm, and the inner diameter is 80 mm. The middle layer coil consists of four equal isosceles right triangles with a right-angled side outer diameter of 200 mm and an inner diameter of 120 mm. The lower layer coil wraps the outer frame of the central region of the middle layer coil, and the difference between its inner and outer diameters is 20 mm. Both the receiving coil and the transmitting coil are composed of optimized couplers and have the same size.

[0086] To verify the correctness of the inference that the optimized coupler has high efficiency and high deviation tolerance capabilities, a system model is built in the finite element simulation software for simulation verification, and an experimental prototype is established to verify the correctness of the simulation and the experiment. The relevant experiments are as Figure 7 shown.

[0087] The simulation and experimental parameters used are shown in Table 1.

[0088] Table 1 Performance Parameters of the Magnetic Coupling Mechanism

[0089]

[0090] To demonstrate the superiority of the transmission efficiency of the optimized coupler during longitudinal and lateral offsets, the DD coil and the square coil are used as controls under the same parameters in Table 1. As shown in (a), (b), and (c) Figure 8 , by combining numerical calculations and through simulation analysis and experimental verification, the transmission efficiency change diagrams as shown in Figure 9 , the transmission efficiency change diagram as shown in Figure 10 , and the efficiency change amplitude diagram can be obtained respectively. It can be found that when the receiving coil is offset, the transmission efficiency of the optimized coupler basically remains stable, and the efficiency change amplitude is much smaller than that of the DD coil and the square coil.

[0091] This method can take into account both the anti-offset characteristics of the system and the overall transmission efficiency, and has higher application value;

[0092] The same or similar reference numerals correspond to the same or similar components; the descriptions of the positional relationships in the drawings are for illustrative purposes only and should not be construed as limitations on the present invention.

[0093] Apply a three-layer composite wireless charging coupler with high-efficiency energy transmission and high anti-offset ability of the present invention to the energy transmitting coil and the energy receiving coil. The wireless charging platform realizes the mutual inductance coupling between its transmitting coil resonant network and receiving coil resonant network, and is used to transmit electric energy from the wireless charging platform part to the output load part. The present invention realizes the optimization and improvement of the wireless charging system in multiple objectives such as high transmission efficiency and high anti-offset characteristics, and has good practicability and application prospects in the field of wireless charging.

[0094] Obviously, the above examples of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A three-layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti-offset ability, characterized in that It includes an upper-layer coil, a middle-layer coil, and a lower-layer coil stacked in sequence from top to bottom. The upper-layer coil, the middle-layer coil, and the lower-layer coil are connected in series in sequence. The upper-layer coil is connected to the power supply module, and the lower-layer coil is connected to the transmitting-end compensation capacitor. The middle-layer coil includes four isosceles right triangles of the same size, namely the first isosceles right triangle, the second isosceles right triangle, the third isosceles right triangle, and the fourth isosceles right triangle. The four isosceles right triangles of the same size are spliced to form a square with the right angle as the center point, and the right-angle sides of the four isosceles right triangles of the same size form a central cross region. The lower-layer coil is a compensation coil for the central cross region of the middle-layer coil, and the lower-layer coil horizontally wraps the central cross region of the middle-layer coil. The upper-layer coil is a compensation coil for the central square region of the lower-layer coil, and the upper-layer coil horizontally wraps the central square region of the lower-layer coil.

2. The three-layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti-offset ability according to claim 1, wherein It is stipulated that the right angle of the first isosceles right triangle faces downward in the page, and the hypotenuse is above the right angle. The left side of the right angle of the first isosceles right triangle is denoted as the first right-angle side (1), and the right side is denoted as the second right-angle side (2). The four isosceles right triangles forming the square region are denoted as the first isosceles right triangle, the second isosceles right triangle, the third isosceles right triangle, and the fourth isosceles right triangle in clockwise order. The winding method of the middle-layer coil is as follows: The first right-angle side (1) of the first right triangle is the starting point. From the first right-angle side (1) of the first right triangle to the second right-angle side (2) of the first right triangle, to the first right-angle side (3) of the second right triangle, to the second right-angle side (4) of the second right triangle, to the first right-angle side (5) of the third right triangle, to the second right-angle side (6) of the third right triangle, to the first right-angle side (7) of the fourth right triangle, to the second right-angle side (8) of the fourth right triangle. At this time, the internal cross winding is completed. Then it is connected to the hypotenuse (9) of the fourth right triangle, then to the hypotenuse (10) of the third right triangle, then to the hypotenuse (11) of the second right triangle, then to the hypotenuse (12) of the first right triangle. The hypotenuse (12) of the first right triangle is not connected to the first right-angle side (1) of the first right triangle, and they are respectively used to connect the upper-layer coil and the lower-layer coil in series.

3. The three - layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti - offset ability according to claim 2, wherein, The current in the middle-layer coil flows along the winding wire. The first, second, third, and fourth isosceles right triangle regions respectively form the first current loop, the second current loop, the third current loop, and the fourth current loop. The current flow directions of these four current loops are all counterclockwise.

4. A three-layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti-offset ability according to claim 2, wherein, The lower-layer coil segment of the first right-angled side (1) of the first isosceles right triangle along the inner direction of the first isosceles right triangle is the thirteenth segment (13) of the lower-layer coil. The lower-layer coil segment of the second right-angled side (2) of the first isosceles right triangle along the inner direction of the first isosceles right triangle is the twenty-fourth segment (24) of the lower-layer coil. The lower-layer coil segment of the first right-angled side (3) of the second isosceles right triangle along the inner direction of the second isosceles right triangle is the twenty-second segment (22) of the lower-layer coil. The lower-layer coil segment of the second right-angled side (4) of the second isosceles right triangle along the inner direction of the second isosceles right triangle is the twenty-first segment (21) of the lower-layer coil. The lower-layer coil segment of the first right-angled side (5) of the third isosceles right triangle along the inner direction of the third isosceles right triangle is the nineteenth segment (19) of the lower-layer coil. The lower-layer coil segment of the second right-angled side (6) of the third isosceles right triangle along the inner direction of the third isosceles right triangle is the eighteenth segment (18) of the lower-layer coil. The lower-layer coil segment of the first right-angled side (7) of the fourth isosceles right triangle along the inner direction of the fourth isosceles right triangle is the sixteenth segment (16) of the lower-layer coil. The lower-layer coil segment of the second right-angled side (8) of the fourth isosceles right triangle along the inner direction of the fourth isosceles right triangle is the fifteenth segment (15) of the lower-layer coil. The lower-layer coil segment connecting the thirteenth segment (13) and the fifteenth segment (15) of the lower-layer coil is the fourteenth segment (14) of the lower-layer coil. The lower-layer coil segment connecting the twenty-second segment (22) and the twenty-fourth segment (24) of the lower-layer coil is the twenty-third segment (23) of the lower-layer coil. The lower-layer coil segment connecting the nineteenth segment (19) and the twenty-first segment (21) of the lower-layer coil is the twentieth segment (20) of the lower-layer coil. The lower-layer coil segment connecting the sixteenth segment (16) and the eighteenth segment (18) of the lower-layer coil is the seventeenth segment (17) of the lower-layer coil; The winding method of the lower-layer coil is as follows: in the horizontal direction, the lower-layer coil is wound closely along the inner diameter of the right-angle side of the isosceles right-angled triangle area of the middle-layer coil, and the number of turns is increased along the inner direction of the right-angled triangle; the fourteenth section (14), the fifteenth section (15), the sixteenth section (16), the seventeenth section (17), the eighteenth section (18), the nineteenth section (19), the twentieth section (20), the twenty-first section (21), the twenty-second section (22), the twenty-third section (23), the twenty-fourth section (24), and the thirteenth section (13) of the lower-layer coil are wound in sequence along the counterclockwise direction. The fourteenth section (14) of the lower-layer coil is not connected to the thirteenth section (13) of the lower-layer coil, and they are respectively connected in series with the middle-layer coil and the transmitting-end compensation capacitor C T ; the fourteenth section (14) of the lower-layer coil is connected to the hypotenuse (12) of the first isosceles right-angled triangle of the middle-layer coil, and the thirteenth section (13) of the lower-layer coil is connected to the transmitting-end compensation capacitor C T .

5. The three-layer composite wireless charging optimized coupler capable of achieving efficient energy transmission and having high anti-offset ability according to claim 4, characterized in that, The current in the lower-layer coil flows along the winding wire, and the overall area of the lower-layer coil forms a fifth current loop in the counterclockwise direction.

6. A three-layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti-offset ability according to claim 4, characterized in that, Denote the intersection point of the thirteenth segment (13) and the twenty-fourth segment (24) of the lower-layer coil as point A. Denote the intersection point of the twenty-first segment (21) and the twenty-second segment (22) of the lower-layer coil as point B. Denote the intersection point of the eighteenth segment (18) and the nineteenth segment (19) of the lower-layer coil as point C. Denote the intersection point of the fifteenth segment (15) and the sixteenth segment (16) of the lower-layer coil as point D. At the corresponding positions of points A, B, C, and D on the upper-layer coil, points E, F, G, and H are respectively set. The coil segment formed by connecting point E to point H is the twenty-sixth segment (26) of the upper-layer coil. The coil segment formed by connecting point H to point G is the twenty-seventh segment (27) of the upper-layer coil. The coil segment formed by connecting point G to point F is the twenty-eighth segment (28) of the upper-layer coil. The coil segment formed by connecting point F to point E is the twenty-fifth segment (25) of the upper-layer coil; The winding method of the upper-layer coil is as follows: in the horizontal direction, the number of turns of the upper-layer coil expands from the inside to the outside; the 26th section (26), 27th section (27), 28th section (28) and 25th section (25) of the upper-layer coil are wound counterclockwise respectively. The 26th section (26) and the 25th section (25) of the upper-layer coil are not connected and are used to connect the middle-layer coil and the power supply module in series respectively; the 25th section (25) of the upper-layer coil is connected to the first right-angled side (1) of the first isosceles right triangle of the middle-layer coil, and the 26th section (26) of the upper-layer coil is connected to the power supply module.

7. A three - layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti - offset ability, as claimed in claim 6, wherein The current of the upper-layer coil flows along the winding wire, and a sixth current loop in the counterclockwise direction is formed in the overall area of the upper-layer coil.

8. The three - layer composite wireless charging optimized coupler capable of achieving efficient energy transfer and having high anti - offset ability according to claim 7, wherein, The overall current of the optimized coupler is emitted from the power supply module, flows from the sixth current loop of the upper-layer coil to the first current loop of the first isosceles right triangle of the middle-layer coil, flows to the second current loop of the second isosceles right triangle, flows to the third current loop of the third isosceles right triangle, flows to the fourth current loop of the fourth isosceles right triangle, flows to the fifth current loop of the lower-layer coil, and then flows out to the transmitting-end compensation capacitor. The overall current of the optimized coupler flows in the counterclockwise direction.

9. The three - layer composite wireless charging optimized coupler capable of achieving efficient energy transmission and having high anti - offset ability according to claim 1, wherein, There is a certain proportional relationship among the number of turns of the upper, middle and lower layer coils of the optimized coupler. Specifically: Denote the wire diameter of a single wire as d, the independent variable x as the change amount of the corresponding coil turns, and the number of turns of the middle-layer coil as N2. Then the magnetic field strength in the central area of the isosceles right triangle coil is: where D is the distance from a point in space to the wire, A = μ0I / 4π, μ0 is the magnetic permeability of vacuum, and I is the magnitude of the current flowing through the wire; Denote the number of turns of the lower-layer coil as N3. Then the central magnetic field strength in the central cross area of the middle-layer coil under the compensation of the lower-layer coil is: Denote the number of turns of the upper-layer coil as N1. Then the central magnetic field strength in the central square area of the middle-layer coil under the compensation of the upper-layer coil is: To ensure that the magnetic field strength remains stable within the coverage area of the optimized coupler, it is necessary to satisfy B Pcoil1 = B Pcoil2 = B Pcoil3 . When the number of turns N2 of the middle layer coil is determined, the number of turns N1 and N3 of the upper and lower layer coils are also determined synchronously.

10. A wireless charging system, characterized in that, Both the transmitting coil at the transmitting end and the receiving coil at the receiving end of the system adopt the optimized coupler described in any one of claims 1-9, and the upper-layer coils of the receiving coil and the transmitting coil are arranged opposite to each other. The transmitting coil and the receiving coil are mutually inductively coupled to realize the transmission of electric energy between the transmitting end and the receiving end.

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