Circular anti-offset coupling mechanism and wireless electric energy transmission system formed by same

Abstract

The invention provides a circular anti-offset coupling mechanism and a wireless power transmission system formed by the same. The problem that an anti-offset structure and a control strategy of an existing circular coil coupling mechanism are complex is solved. The circular anti-offset coupling mechanism comprises a transmitting end and a receiving end, the transmitting end comprises a first transmitting coil L1 and a second transmitting coil L2, and the receiving end comprises a first receiving coil L3 and a second receiving coil L4; the first transmitting coil L1 and the first receiving coil L3 are planar circular coils, the second transmitting coil L2 and the second receiving coil L4 are composite planar circular coils formed by winding a lead, each composite planar circular coil comprises four fan-shaped areas, and the winding directions of the leads in the adjacent fan-shaped areas are opposite. The transmitting end and the receiving end both comprise the planar circular coil and the composite planar circular coil, so that the system can achieve the anti-offset effect in the X, Y and Z directions, and it is ensured that the system can achieve stable output when offset occurs.

Description

Technical Field

[0001] The invention relates to the field of wireless power transmission, in particular to a circular anti-deviation coupling mechanism and a wireless power transmission system composed of the circular anti-deviation coupling mechanism. Background Art

[0002] With the rapid development of science and technology in the world, unmanned equipment based on artificial intelligence has gradually been integrated into all aspects of people's lives and production. The previous wired charging method can no longer meet the charging needs of current intelligent unmanned equipment. First of all, wired charging has the limitation of distance of the use location and the need to unplug and plug the charging plug. Once the plugging and unplugging are too frequent, the connection will be poor, which will lead to reduced charging efficiency, shortened life of electrical equipment, and short circuit leakage. In addition, the number of unmanned equipment in various fields is increasing, including the field of smart electric vehicles, smart homes, and smart detection. The use of wireless power transmission technology to power unmanned equipment can not only ignore the shortcomings of wired charging, but also increase the service life of unmanned equipment, and is more in line with unmanned management methods.

[0003] Symmetrical circular coils are widely used in the field of wireless power transmission for unmanned equipment. However, in practical applications, most electrical equipment requires stable power supply. The internal resistance of the equipment may change during the charging process. In order to ensure the stability of the power supply voltage or current, the output voltage or current of the system needs to be independent of the load. In addition, when the WPT system is working, changes in the load placement may affect the system output effect. Therefore, when designing a wireless charging system, not only the stable output characteristics but also the anti-drift characteristics should be considered.

[0004] At present, the main methods for improving the anti-offset characteristics of circular coils are omnidirectional wireless charging and compensating feedback circuits. The omnidirectional wireless charging method uses two or three mutually orthogonal transmitting coils to achieve omnidirectional wireless power transmission within a certain spatial range, thereby improving the anti-offset characteristics of the system. However, its transmitter control circuit and control strategy are relatively complex. The method of using a compensating feedback circuit uses various compensating electronic components to form a feedback circuit. Once a load offset is detected, the load will be fed back through the circuit to keep the output at both ends of the load stable. Since this method uses more electronic components, its circuit structure is often more complex and larger in size. Summary of the invention

[0005] The purpose of the present invention is to provide a circular anti-deviation coupling mechanism and a wireless power transmission system composed of the same, so as to solve the technical problems of the anti-deviation structure and the complex control strategy of the existing circular coil coupling mechanism.

[0006] A circular anti-deviated coupling mechanism comprises a transmitting end and a receiving end, wherein the transmitting end comprises a first transmitting coil L 1 and the second transmitting coil L 2 , the receiving end includes a first receiving coil L 3 and the second receiving coil L 4 ;

[0007] The first transmitting coil L 1 and the first receiving coil L 3 are all planar circular coils, the second transmitting coil L 2 and the second receiving coil L 4 All of them are composite planar circular coils, which include four sector-shaped areas, and the winding directions of the wires in adjacent sector-shaped areas are opposite.

[0008] Optionally, the first transmitting coil L 1 and the second transmitting coil L 2 The first receiving coil L is stacked. 3 and the second receiving coil L 4 Cascade settings.

[0009] Optionally, the four sector-shaped areas of the composite planar circular coil are all wound by the same conducting wire.

[0010] A wireless power transmission system comprises the circular anti-deviating coupling mechanism mentioned above.

[0011] Optionally, a DC power supply U IN , full-bridge inverter and primary side compensation circuit;

[0012] The primary compensation circuit includes a primary LCC topology circuit and a primary compensation capacitor C P2 The two input ends of the primary LCC topology circuit are respectively connected to the two output ends of the full-bridge inverter, and the two output ends of the primary LCC topology circuit are respectively connected to the first transmitting coil L 1 Connect both ends of the

[0013] The primary compensation capacitor C P2 One end of the primary compensation capacitor C is connected to an output end of the full-bridge inverter. P2 The other end is connected to the second transmitting coil L 2 One end of the second transmitting coil L is connected to 2 The other end is connected to the other output end of the full-bridge inverter.

[0014] Optionally, it also includes a secondary compensation circuit, a rectifier, and a filter capacitor C connected in sequence. f and load R L ;

[0015] The secondary side compensation circuit includes a secondary side LCC topology circuit and a secondary side compensation capacitor C S1 The two input terminals of the secondary side LCC topology circuit are respectively connected to the second receiving coil L 4 The two ends of the secondary LCC topology circuit are connected, one output end of the secondary LCC topology circuit is connected to an input end of the rectifier, and the other output end of the secondary LCC topology circuit is connected to the first receiving coil L 3 One end of the connection;

[0016] The secondary side compensation capacitor C S1 One end of the first receiving coil L 3 The other end of the secondary compensation capacitor C S1 The other end is connected to the other input end of the rectifier.

[0017] Optionally, the primary LCC topology circuit includes a primary compensation inductor L f1 , primary compensation capacitor C f1 And the primary compensation capacitor C P1 ;

[0018] The primary compensation inductor L f1 One end of the primary compensation capacitor C f1 One end is connected to the primary compensation capacitor C P1 One end of the primary compensation inductor L f1 The other end is connected to an output end of the full-bridge inverter, and the primary compensation capacitor C f1 The other end of the first transmitting coil L 1 One end of the primary compensation capacitor C is connected to the other output end of the full-bridge inverter. P1 The other end of the first transmitting coil L 1 The other end of the connection.

[0019] Optionally, the secondary side LCC topology circuit includes a secondary side compensation inductor L f2 , secondary compensation capacitor C f2 And the secondary compensation capacitor C S2 ;

[0020] The primary compensation inductor L f1 One end of the first receiving coil L 3 One end of the primary compensation inductor L f1 The other end is connected to the secondary compensation capacitor C f2 One end is connected to the secondary compensation capacitor C S2 One end of the secondary compensation capacitor C f2 The other end is connected to the second receiving coil L 4One end of the rectifier is connected to an input terminal of the rear rectifier, and the secondary compensation capacitor C S2 The other end is connected to the second receiving coil L 4 The other end of the connection.

[0021] Optionally, the voltage gain G of the wireless power transfer system VVh for:

[0022]

[0023] In the formula, is the output current of the system, is the inverter output voltage of the system, R L For load R L Resistance value, M 13 is the first transmitting coil L 1 With the first receiving coil L 3 Mutual inductance value, M 24 The second transmitting coil L 2 With the second receiving coil L 4 Mutual inductance value, L f1 The primary compensation inductor L f1 The inductance value, L f2 For the secondary side compensation inductor L f2 The inductance value.

[0024] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0025] The transmitting end and the receiving end of the coupling mechanism of the present application both include a planar circular coil and a composite planar circular coil. Through the design of the coupling mechanism and the design of the system topology, the entire wireless power transmission system can achieve anti-offset effects in the three directions of X, Y, and Z, ensuring that the system can achieve stable output when offset occurs.

[0026] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings of the present invention are as follows.

[0028] Figure 1 It is a structural schematic diagram of the circular anti-deviating coupling mechanism of the present invention.

[0029] Figure 2 It is an exploded view of the circular anti-deviating coupling mechanism of the present invention.

[0030] Figure 3 This is a magnetic field distribution diagram of the composite planar circular coil of the present invention.

[0031] Figure 4 FIG. 4 is a circuit diagram of a wireless power transmission system of the present invention.

[0032] Figure 5 A simplified circuit model diagram of the wireless power transmission system of the present invention.

[0033] Figure 6 is the mutual inductance M in the simulation of the present invention 13 and M 24 Graph with positive X-axis offset.

[0034] Figure 7 is the mutual inductance M in the simulation of the present invention 13 and M 24 Graph of the displacement along the Z axis.

[0035] Figure 8 is the load voltage U in the simulation of the present invention L Graph with positive X-axis offset.

[0036] Fig. 9 is the load voltage U in the simulation of the present invention L Graph of the displacement along the Z axis. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0038] Embodiment 1:

[0039] like Figure 1 , Figure 2 and Figure 3 The circular anti-deviation coupling mechanism shown in the figure comprises a transmitting end and a receiving end, wherein the transmitting end comprises a first transmitting coil L arranged in a stacked manner. 1 and the second transmitting coil L 2 , the receiving end includes a first receiving coil L 3 and the second receiving coil L 4 ;

[0040] The first transmitting coil L 1 and the first receiving coil L 3 are all planar circular coils, the second transmitting coil L 2 and the second receiving coil L 4 All of them are composite planar circular coils wound by the same conducting wire. The composite planar circular coils include four sector-shaped areas, and the winding directions of the conducting wires in adjacent sector-shaped areas are opposite.

[0041] In this embodiment, if Figure 3 As shown, the diagonal sector regions are wound in the same manner, which are all wound clockwise or counterclockwise. Since the composite planar circular coil is a symmetrical structure, there is no cross coupling between the planar circular coils and the composite planar circular coils, which facilitates system analysis and system topology design.

[0042] In this embodiment, the first transmitting coil L 1 and the first receiving coil L 3的 The radius is 150mm, the number of turns is 25, and the coil self-inductance is 125uH; the second transmitting coil L 2 and the second receiving coil L 4 The radius is 150mm, the number of turns is 15, the coil self-inductance is 96uH, the diameter of all wires is 4mm, and the transmission distance of this circular anti-offset coupling mechanism is 100mm.

[0043] Embodiment 2:

[0044] like Figure 4 A wireless power transmission system is shown, characterized in that it includes a circular anti-deviating coupling mechanism as described in Example 1, and also includes a primary circuit and a secondary circuit;

[0045] like Figure 4 As shown, the primary circuit includes a DC power supply U connected in sequence IN , full-bridge inverter and primary side compensation circuit;

[0046] The primary compensation circuit includes a primary LCC topology circuit and a primary compensation capacitor C P2 The two input ends of the primary LCC topology circuit are respectively connected to the two output ends of the full-bridge inverter, and the two output ends of the primary LCC topology circuit are respectively connected to the first transmitting coil L 1 Connect both ends of the

[0047] The primary compensation capacitor C P2 One end of the primary compensation capacitor C is connected to an output end of the full-bridge inverter. P2 The other end is connected to the second transmitting coil L 2 One end of the second transmitting coil L is connected to 2 The other end is connected to the other output end of the full-bridge inverter.

[0048] like Figure 4 As shown, the primary LCC topology circuit includes a primary compensation inductor L f1 , primary compensation capacitor C f1 And the primary compensation capacitor C P1 ;

[0049] The primary compensation inductor L f1One end of the primary compensation capacitor C f1 One end is connected to the primary compensation capacitor C P1 One end of the primary compensation inductor L f1 The other end is connected to an output end of the full-bridge inverter, and the primary compensation capacitor C f1 The other end of the first transmitting coil L 1 One end of the primary compensation capacitor C is connected to the other output end of the full-bridge inverter. P1 The other end of the first transmitting coil L 1 The other end of the connection.

[0050] In this embodiment, the full-bridge inverter is composed of four power MOSFET tubes.

[0051] like Figure 4 As shown, the secondary circuit includes a secondary compensation circuit, a rectifier, and a filter capacitor C connected in sequence. f and load R L ;

[0052] The secondary side compensation circuit includes a secondary side LCC topology circuit and a secondary side compensation capacitor C S1 The two input terminals of the secondary side LCC topology circuit are respectively connected to the second receiving coil L 4 The two ends of the secondary LCC topology circuit are connected, one output end of the secondary LCC topology circuit is connected to an input end of the rectifier, and the other output end of the secondary LCC topology circuit is connected to the first receiving coil L 3 One end of the connection;

[0053] The secondary side compensation capacitor C S1 One end of the first receiving coil L 3 The other end of the secondary compensation capacitor C S1 The other end is connected to the other input end of the rectifier.

[0054] like Figure 4 As shown, the secondary side LCC topology circuit includes a secondary side compensation inductor L f2 , secondary compensation capacitor C f2 And the secondary compensation capacitor C S2 ;

[0055] The primary compensation inductor L f1 One end of the first receiving coil L 3 One end of the primary compensation inductor L f1 The other end is connected to the secondary compensation capacitor C f2 One end is connected to the secondary compensation capacitor C S2 One end of the secondary compensation capacitor C f2 The other end is connected to the second receiving coil L4 One end of the rectifier is connected to an input terminal of the rear rectifier, and the secondary compensation capacitor C S2 The other end is connected to the second receiving coil L 4 The other end of the connection.

[0056] In this embodiment, the rectifier is composed of four diodes, the primary side LCC topology circuit and the secondary side compensation capacitor C S1 The LCC-S topology is formed, and the primary compensation capacitor C P2 Together with the secondary LCC topology circuit, it forms an S-LCC topology. The mutual inductances between the four coils are M 12 、M 13 、M 14 、M 23 、M 24 and M 34 .

[0057] Figure 4 The circuit diagram shown can be simplified to Figure 5 The circuit shown is driven by a sinusoidal voltage source with an angular frequency of ω. This topology can be represented by the following equation:

[0058]

[0059] According to Kirchhoff's laws, the circuit can be expressed as:

[0060]

[0061] Where:

[0062] Z 00 =jωL f1 +1 / (jωC f1 ),Z 01 =Z 10 =-1 / (jωC f1 )

[0063] Z 02 =Z 20 =0,Z 03 =Z 30 =0,Z 04 =Z 40 =0

[0064] Z 11 =1 / (jωC f1 )+1 / (jωC p1 )+jωL 1

[0065] Z 12 =Z 21 =-jωM 13

[0066] Z 13 =Z 31 =jωM 12 ,Z 14 =Z 41 =-jωM 14

[0067] Z 22 =jωL 3 +1 / (jωC s1 )+jωL f2 +1 / (jωC f2 )+R L

[0068] Z 23 =Z 32 =-jωM 23 ,Z 24 =Z 42 =jωM 34 -1 / (jωC f2 )

[0069] Z 33 =jωL 2 +1 / (jωC p2 ),Z 34 =Z 43 =-jωM 24

[0070] Z 44 =jωL 4 +1 / (jωC s2 )+1 / (jωC f2 )

[0071] In this embodiment, due to the planar circular coil and the composite planar circular coil structure designed in this system, the cross coupling (M 12 、M 14 、M 23 and M 34 ) has a much smaller impact on the system output than the main coupling (M 13 and M 24 ) on the system output. Therefore, the cross coupling (M 12 、M 14 、M 23 and M 34 ). By solving, we get:

[0072]

[0073] Then the voltage gain G of the wireless power transmission system is VVh for:

[0074]

[0075] In the formula, is the output current of the system, is the inverter output voltage of the system, R L For load R L Resistance value, M 13 is the first transmitting coil L 1 With the first receiving coil L 3 Mutual inductance value, M 24 The second transmitting coil L 2 With the second receiving coil L 4 Mutual inductance value, L f1 The primary compensation inductor L f1 The inductance value, L f2 For the secondary side compensation inductor L f2 The inductance value.

[0076] From the above formula, we can know that when the load is offset, the main coupling M 13 and M 24 will decrease, which leads to M 13 / L f1 Reduce and L f2 / M 24 Increase. If the parameters are properly selected, M can be offset. 13 and M 24 The effect of increasing or decreasing the voltage gain G VVh It can remain relatively constant within a certain range, that is, the output stable load voltage can be maintained within a certain offset range.

[0077] Simulation verification:

[0078] In order to verify the effectiveness of this method for multi-directional anti-deviation of circular coils, according to Figure 4 The circuit diagram shown in the figure is used to build a Simulink simulation model, and its circuit parameters are shown in Table 1.

[0079] Table 1 Simulink circuit simulation model parameters

[0080] parameter Parameter Value parameter Parameter Value <![CDATA[L 1 ]]> 125uH <![CDATA[C P1 ]]> 34nF <![CDATA[L 3 ]]> 125uH <![CDATA[C P2 ]]> 36.5nF <![CDATA[L 2 ]]> 96uH <![CDATA[C S1 ]]> 28nF <![CDATA[L 4 ]]> 96uH <![CDATA[C S2 ]]> 38.2nF <![CDATA[L f1 ]]> 22.1uH <![CDATA[C f1 ]]> 158.6nF <![CDATA[L f2 ]]> 4.4uH <![CDATA[C f2 ]]> 796.8nF <![CDATA[R L ]]> 5Ω <![CDATA[U IN ]]> 100V

[0081] Since the coils designed in the present invention are completely symmetrical, the effects of the receiving coils offset along the positive direction of the X-axis, the negative direction of the X-axis, the positive direction of the Y-axis, and the negative direction of the Y-axis are completely consistent. Therefore, this time, only the position offset of the receiving coils along the positive direction of the X-axis (D = 100mm fixed) and the Z-axis direction (i.e., the receiving distance D changes) is simulated and verified. First, the mutual inductance M between the planar circular coils 13 Mutual inductance M between the composite planar circular coil 24 As the receiving coil deflects, Figure 6 and Figure 7 shown.

[0082] Bring all the data into the Simulink simulation model to observe how the output voltage at the load end changes with the mutual inductance. The final data is summarized as follows: Figure 8 and Fig. 9 shown.

[0083] from Figure 8 It can be seen that when the load is offset in the positive direction of the X-axis (0-70mm, 100-210mm) or the receiving distance D changes between 10-160mm, the system output voltage can always output 200V±10%, and based on the symmetry, it can be inferred that the anti-offset performance in the negative direction of the X-axis, the positive direction of the Y-axis, and the negative direction of the Y-axis is consistent with the anti-offset performance in the positive direction of the X-axis, which greatly improves the anti-offset performance of the circular coupling mechanism in the three directions of X, Y, and Z.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A circular anti-deviating coupling mechanism, comprising a transmitting end and a receiving end, characterized in that: The transmitting end includes a first transmitting coil L1 and a second transmitting coil L2, and the receiving end includes a first receiving coil L3 and a second receiving coil L4; The first transmitting coil L1 and the first receiving coil L3 are both planar circular coils, and the second transmitting coil L2 and the second receiving coil L4 are both composite planar circular coils. The composite planar circular coil includes four sector-shaped areas, and the winding directions of the wires in adjacent sector-shaped areas are opposite.

2. A circular anti-deviating coupling mechanism according to claim 1, characterized in that: The first transmitting coil L1 and the second transmitting coil L2 are stacked, and the first receiving coil L3 and the second receiving coil L4 are stacked.

3. A circular anti-deviating coupling mechanism according to claim 1, characterized in that: The four sector-shaped areas of the composite planar circular coil are all wound by the same conducting wire.

4. A wireless power transmission system, characterized in that: It comprises a circular anti-deviating coupling mechanism as described in any one of claims 1 to 3.

5. A wireless power transmission system according to claim 4, characterized in that: Also includes a DC power supply U connected in sequence IN , full-bridge inverter and primary side compensation circuit; The primary compensation circuit includes a primary LCC topology circuit and a primary compensation capacitor C P2 , the two input ends of the primary LCC topology circuit are respectively connected to the two output ends of the full-bridge inverter, and the two output ends of the primary LCC topology circuit are respectively connected to the two ends of the first transmitting coil L1; The primary compensation capacitor C P2 One end of the primary compensation capacitor C is connected to an output end of the full-bridge inverter. P2 The other end of is connected to one end of the second transmitting coil L2, and the other end of the second transmitting coil L2 is connected to the other output end of the full-bridge inverter.

6. A wireless power transmission system according to claim 4, characterized in that: It also includes a secondary compensation circuit, a rectifier, and a filter capacitor C connected in sequence. f and load R L ; The secondary side compensation circuit includes a secondary side LCC topology circuit and a secondary side compensation capacitor C S1 , the two input ends of the secondary LCC topology circuit are respectively connected to the two ends of the second receiving coil L4, an output end of the secondary LCC topology circuit is connected to an input end of the rectifier, and the other output end of the secondary LCC topology circuit is connected to one end of the first receiving coil L3; The secondary side compensation capacitor C S1 One end of the secondary side compensation capacitor C is connected to the other end of the first receiving coil L3. S1 The other end is connected to the other input end of the rectifier.

7. A wireless power transmission system according to claim 5, characterized in that: The primary side LCC topology circuit includes a primary side compensation inductor L f1 , primary compensation capacitor C f1 And the primary compensation capacitor C P1 ; The primary compensation inductor L f1 One end of the primary compensation capacitor C f1 One end is connected to the primary compensation capacitor C P1 One end of the primary compensation inductor L f1 The other end is connected to an output end of the full-bridge inverter, and the primary compensation capacitor C f1 The other end of the primary compensation capacitor C is connected to one end of the first transmitting coil L1 and then to the other output end of the full-bridge inverter. P1 The other end of is connected to the other end of the first transmitting coil L1.

8. A wireless power transmission system according to claim 6, characterized in that: The secondary side LCC topology circuit includes a secondary side compensation inductor L f2 , secondary compensation capacitor C f2 and the secondary compensation capacitor C S2 ; The primary compensation inductor L f1 One end of the primary compensation inductor L is connected to one end of the first receiving coil L3. f1 The other end is connected to the secondary compensation capacitor C f2 One end is connected to the secondary compensation capacitor C S2 One end of the secondary compensation capacitor C f2 The other end of the second receiving coil L4 is connected to an input end of the rectifier, and the secondary compensation capacitor C S2 The other end of is connected to the other end of the second receiving coil L4.

9. A wireless power transmission system according to claim 4, characterized in that: Voltage gain G of wireless power transmission system VVh for: In the formula, is the output current of the system, is the inverter output voltage of the system, R L For load R L Resistance value, M 13 is the mutual inductance between the first transmitting coil L1 and the first receiving coil L3, M 24 is the mutual inductance between the second transmitting coil L2 and the second receiving coil L4, L f1 The primary compensation inductor L f1 The inductance value, L f2 For the secondary side compensation inductor L f2 The inductance value.

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