Electric vehicle wireless charging device and road surface structure with large transmission distance

Abstract

The present invention relates to a wireless charging device for electric vehicles with a large transmission distance and a pavement structure, wherein the wireless charging device includes a primary device and a secondary device, wherein the primary device is composed of a primary coil, a primary ferrite plate and a primary aluminum plate from top to bottom, and the secondary device is composed of a secondary aluminum plate, a secondary ferrite plate and a secondary coil from top to bottom; the maximum transmission distance of the wireless charging device is 300mm, and the coupling coefficient between the primary coil and the secondary coil is not less than 0.1; the pavement structure is embedded with the primary device in the wireless charging device, and the pavement structure is composed of a pavement upper layer, a primary device layer, a pavement lower layer, a road base layer and a road cushion layer from top to bottom. The present invention can achieve a good coupling effect between the wireless primary coil and the secondary coil when the transmission distance is 300mm, thereby meeting the use requirements when buried in the pavement structure, and is widely used in various vehicle models.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging and roads, and in particular to a wireless charging device for electric vehicles with a large transmission distance and a road surface structure. Background Art

[0002] Electric vehicles are powered by onboard power and use motors to drive the wheels. They can use clean and renewable energy such as solar energy and wind energy to better solve the problems of motor vehicle emissions pollution and energy shortages. They are a strategic emerging industry in my country. At present, the charging of electric vehicles depends on wired charging piles and chargers. The wired charging method often has greater safety hazards and is prone to leakage and electric shock accidents. In addition, the limited capacity of the car battery will also cause users to have mileage anxiety.

[0003] Wireless charging technology is a new charging method that uses electromagnetic fields as a medium to achieve power transmission. Wireless charging is used to charge electric vehicles. It does not contain external leakage ports and does not require manual operation. It can be charged in both static and moving states. Compared with wired charging methods, it has the advantages of safe operation, flexible solution configuration, and no mileage anxiety.

[0004] The current problem with using wireless charging technology in road structures is that in order to protect the wireless charging device and meet the road surface flatness requirements, the wireless charging panel should be embedded in the road surface structure, but this increases the transmission distance between the wireless charging transmitting coil and the receiving coil, resulting in a decrease in the efficiency of wireless charging of electric vehicles. Therefore, in order to shorten the distance between the primary coil and the secondary coil, some studies have proposed the use of raised pavement, but this raised pavement not only affects driving comfort, but also creates safety hazards. In addition, since the primary coil is not currently considered to be buried in the road surface, the transmission distance of the coils used in most current electric vehicle wireless charging studies is less than 250mm. Furthermore, when the transmission distance of the existing primary and secondary coils increases to 300mm, the coupling effect between the coils is poor and cannot meet the use requirements. Summary of the invention

[0005] The purpose of the present invention is to provide an electric vehicle wireless charging device and pavement structure with long-distance transmission, so that the wireless primary coil and the secondary coil can still have a good coupling effect when the maximum transmission distance reaches 300mm, thereby meeting the use requirements when buried in the pavement structure and being widely used in various vehicle models.

[0006] A wireless charging device for electric vehicles with a large transmission distance comprises a primary device and a secondary device, wherein the primary device is composed of a primary coil, a primary ferrite plate and a primary aluminum plate from top to bottom, and the secondary device is composed of a secondary aluminum plate, a secondary ferrite plate and a secondary coil from top to bottom; the maximum transmission distance of the wireless charging device is 300 mm, and the coupling coefficient between the primary coil and the secondary coil is not less than 0.1.

[0007] Furthermore, the primary side device is arranged inside the pavement structure, and the secondary side device is arranged at the lower end of the car and is smaller than the size of the car chassis.

[0008] Furthermore, the primary coil and the secondary coil are wound using Litz wire with a wire diameter of 5 mm.

[0009] Furthermore, in the primary device, the dimensions of the primary coil are: the length and width of the outer diameter are 650mm and 500mm respectively, the length and width of the inner diameter are 290mm and 140mm respectively, the number of coil turns is 8 turns, double wire is wound in parallel, the turn spacing is 6.66mm, and the chamfers are 45° all around; the primary ferrite plate is made of manganese-zinc ferrite with a relative magnetic permeability of 3300, and the dimensions are: 650mm long, 500mm wide, and 5mm thick. It is placed directly under the primary coil with no air gap between the primary coil; the dimensions of the primary aluminum plate are 750mm long, 600mm wide, and 3mm thick, and the distance between the upper surface of the primary aluminum plate and the lower surface of the primary ferrite plate is 30mm.

[0010] Furthermore, in the secondary device, the secondary coil adopts a square structure with chamfers, and its dimensions are: outer diameter 480mm, inner diameter 210mm, number of turns 9 turns, turn spacing 11.25mm, and chamfers of 45° on all sides; the secondary ferrite plate is square, and manganese-zinc ferrite is selected, with a relative magnetic permeability of 3300, dimensions: side length 500mm, thickness 5mm, directly placed on the secondary coil, and there is no air gap between the secondary coil; the secondary aluminum plate is square, with dimensions: side length 520mm, thickness 8mm, directly placed on the secondary ferrite plate, and there is no air gap between the secondary ferrite plate.

[0011] Furthermore, the primary device is first encapsulated with resin to achieve waterproof effect, and then encapsulated with cement concrete to bear the traffic load. The encapsulation thickness of the resin should be at least 5mm, and the encapsulation thickness of the cement concrete should be at least 30mm. The resin is epoxy resin or polyurethane.

[0012] Furthermore, the secondary device is packaged in a plastic shell.

[0013] A wireless charging pavement structure, wherein the primary device in the wireless charging device is embedded in the pavement structure, and the pavement structure comprises, from top to bottom, an upper pavement layer, a primary device layer, a lower pavement layer, a road base layer and a road cushion layer.

[0014] Furthermore, the wireless charging primary device layer is arranged at the center line of each lane, embedded in the lower layer of the road surface, arranged adjacent to each other in sequence along the length direction of the lane, and connected to the power grid line; when the wireless charging primary device layer is arranged, the prefabricated cement concrete is first placed in the ditch, and then the lower layer material of the road surface is poured to lay the road surface structure.

[0015] Furthermore, the upper layer, lower layer and road cushion layer of the road surface use conventional road surface materials; the road base layer uses a soil-rock roadbed that has been waterproofed.

[0016] Beneficial effects of the present invention:

[0017] 1. By modifying the structure of the primary coil and the secondary coil, the problem of limited transmission distance of the electromagnetic coupling structure is overcome, the power loss is effectively reduced, and the charging efficiency is improved.

[0018] 2. At the same time, a rectangular coil structure with chamfers is arranged inside the road surface. Compared with the circular coil, a rectangular coil with chamfers is arranged in the road surface structure to form a uniform magnetic field in space, ensuring the stability of energy transmission during dynamic driving of electric vehicles.

[0019] 3. The wireless charging pavement structure proposed in the present invention buries the wireless charging equipment underground. On the one hand, it will not affect the flatness of the road and ensure the normal passage of vehicles; on the other hand, the pavement structure bears the traffic load and environmental loads such as rain and sunlight, ensuring that the wireless charging equipment is not damaged and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 (a) is a front view of the wireless charging primary device of the present invention;

[0022] Figure 1 (b) is a side view of the wireless charging primary device of the present invention;

[0023] Figure 1 (c) is a top view of the wireless charging primary device of the present invention;

[0024] Figure 1 (d) is a vertical view of the wireless charging primary device of the present invention;

[0025] Figure 2 (a) is a front view of the wireless charging secondary device of the present invention;

[0026] Figure 2 (b) is a side view of the wireless charging secondary device of the present invention;

[0027] Figure 2 (c) is a top view of the wireless charging secondary device of the present invention;

[0028] Figure 2 (d) is a vertical view of the wireless charging secondary device of the present invention;

[0029] Figure 3 A simplified cross-sectional view of a road surface structure in which a wireless charging device is embedded in the present invention;

[0030] Figure 4 A schematic longitudinal cross-sectional view of a road surface structure in which a wireless charging device is embedded in the present invention;

[0031] Figure 5 A schematic diagram of a wireless charging highway lane of the present invention;

[0032] Figure 6 This is a schematic diagram of a car of the present invention traveling on a wireless charging road surface.

[0033] Description of reference numerals:

[0034] 1-primary aluminum plate, 2-primary ferrite plate, 3-primary coil, 4-secondary aluminum plate, 5-secondary ferrite plate, 6-secondary coil, 7-primary device, 8-secondary device, 9-pavement upper layer, 10-pavement lower layer, 11-pavement base layer, 12-pavement cushion layer, 13-power supply grid. DETAILED DESCRIPTION

[0035] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0036] Example 1

[0037] like Figure 1 and 2As shown, a wireless charging device for electric vehicles with a large transmission distance includes a primary device 7 and a secondary device 8. The coupling coefficient of the device proposed by the present invention is 0.011 when the transmission distance is 300mm using an LCR tester, which meets the use requirements. The power grid 13 is used to input a 65V high-frequency AC voltage to the primary device 7, and the load of the electric vehicle is 10Ω. After the magnetic field transmission, the power received by the electric vehicle is tested to be 3.23kW, and the transmission efficiency is 86.54%, which meets the specification requirements.

[0038] Among them, the primary device 7 is composed of a primary coil 3, a primary ferrite plate 2 and a primary aluminum plate 1 from top to bottom, and the secondary device is composed of a secondary aluminum plate 4, a secondary ferrite plate 5 and a secondary coil 6 from top to bottom; the maximum transmission distance of the wireless charging device is 300mm, and the coupling coefficient between the primary coil 3 and the secondary coil 6 is not less than 0.1.

[0039] The primary device 7 is arranged inside the pavement structure, and the secondary device 8 is arranged at the lower end of the vehicle and is smaller than the size of the vehicle chassis.

[0040] The primary coil 3 and the secondary coil 6 are wound with Litz wire, and the wire diameter is 5 mm.

[0041] The dimensions of the primary coil 3 are: the length and width of the outer diameter are 650mm and 500mm respectively, the length and width of the inner diameter are 290mm and 140mm respectively, the number of coil turns is 8 turns, double wire is wound in parallel, the turn spacing is 6.66mm, and the chamfers are 45° all around; the primary ferrite plate 2 is made of manganese-zinc ferrite with a relative magnetic permeability of 3300, and the dimensions are: 650mm long, 500mm wide, and 5mm thick. It is placed directly under the primary coil 3 with no air gap between the primary coil 3; the dimensions of the primary aluminum plate 1 are 750mm long, 600mm wide, and 3mm thick, and the distance between the upper surface of the primary aluminum plate and the lower surface of the primary ferrite plate 2 is 30mm.

[0042] In the secondary device 8, the secondary coil 6 adopts a square structure with chamfers, and its dimensions are: outer diameter 480mm, inner diameter 210mm, number of turns 9 turns, turn spacing 11.25mm, and chamfers of 45° on all sides; the secondary ferrite plate 5 is made of manganese-zinc ferrite with a relative magnetic permeability of 3300, and its dimensions are: side length 500mm, thickness 5mm, and it is directly placed on the secondary coil 6 without an air gap between the secondary coil 6; the secondary aluminum plate 5 has a side length of 520mm and a thickness of 8mm, and is directly placed on the secondary ferrite plate 5 without an air gap between the secondary ferrite plate 5.

[0043] The primary device 7 is first encapsulated with resin to achieve waterproof effect, and then encapsulated with cement concrete to bear the traffic load. The encapsulation thickness of the resin should be at least 5mm, and the encapsulation thickness of the cement concrete should be at least 30mm. The resin is epoxy resin or polyurethane.

[0044] The secondary device 8 is packaged in a plastic shell.

[0045] Example 2

[0046] like Figure 3 and 4 As shown, a wireless charging highway includes a pavement system and a wireless charging system. The pavement system includes, from top to bottom, a pavement upper layer 9, a wireless charging primary device 7, a pavement lower layer 10, a pavement base layer 11, and a pavement cushion layer 12. The wireless charging primary device is arranged in the middle of each lane and embedded in the pavement lower layer 10. The power supply grid 13 is arranged below the wireless charging primary device 7.

[0047] The power supply grid 13 includes a power supply source, and also has an energy storage power station and a grid switching device arranged on the road side, which are connected to the power supply grid to supply power.

[0048] In the specific implementation of the present invention, firstly, a wireless charging primary device 7 and a power line 13 are laid on the road, and a secondary device 8 is installed at the lower end of an electric car. The electric car travels along the center of the road. When it travels to the road surface paved with the primary device 7, magnetic induction coupling occurs between the secondary coil 6 and the primary coil 3, realizing the transmission of electric energy from the ground end to the car end, thereby charging the electric car while driving.

[0049] Example 3

[0050] Different models of electric vehicles have different ground clearances. When the present invention is implemented, it can also be applied to the case where the transmission distance between the primary side device and the secondary side device is less than 300 mm. A communication module and an electronic control module can be added to the secondary side device 8 to enable the driver to monitor the charging status of the car through the in-car device or mobile phone, and decide whether to continue driving on the wireless charging road surface.

[0051] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled 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 list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A wireless charging device for electric vehicles with a large transmission distance, characterized in that: It includes a primary device and a secondary device, wherein the primary device is composed of a primary coil, a primary ferrite plate and a primary aluminum plate from top to bottom, and the secondary device is composed of a secondary aluminum plate, a secondary ferrite plate and a secondary coil from top to bottom; the maximum transmission distance of the wireless charging device is 300mm, and the coupling coefficient between the primary coil and the secondary coil is not less than 0.1; the primary coil and the secondary coil are wound with Litz wire, and the wire diameter of the Litz wire is 5mm; In the primary device, the dimensions of the primary coil are: the length and width of the outer diameter are 650mm and 500mm respectively, the length and width of the inner diameter are 290mm and 140mm respectively, the number of coil turns is 8 turns, double wire is used for winding, the turn spacing is 6.66mm, and the chamfers are 45° all around; the primary ferrite plate is made of manganese-zinc ferrite, with a relative magnetic permeability of 3300, and the dimensions are: 650mm long, 500mm wide, and 5mm thick. It is placed directly under the primary coil, and there is no air gap between the primary coil; the dimensions of the primary aluminum plate are 750mm long, 600mm wide, and 3mm thick, and the distance between the upper surface of the primary aluminum plate and the lower surface of the primary ferrite plate is 30mm; In the secondary device, the secondary coil adopts a square structure with chamfers, and its dimensions are: outer diameter 480mm, inner diameter 210mm, number of turns 9 turns, turn spacing 11.25mm, and chamfers of 45° on all sides; the secondary ferrite plate is square, manganese-zinc ferrite is selected, the relative magnetic permeability is 3300, the dimensions are: side length 500mm, thickness 5mm, directly placed on the secondary coil, and there is no air gap between the secondary coil; the secondary aluminum plate is square, the dimensions are: side length 520mm, thickness 8mm, directly placed on the secondary ferrite plate, and there is no air gap between the secondary ferrite plate.

2. The electric vehicle wireless charging device with a large transmission distance according to claim 1 is characterized in that: The primary side device is arranged inside the pavement structure, and the secondary side device is arranged at the lower end of the vehicle and is smaller than the size of the vehicle chassis.

3. The electric vehicle wireless charging device with a large transmission distance according to claim 2 is characterized in that: The primary device is first encapsulated with resin to achieve waterproof effect, and then encapsulated with cement concrete to bear the traffic load. The encapsulation thickness of the resin should be at least 5mm, and the encapsulation thickness of the cement concrete should be at least 30mm. The resin is epoxy resin or polyurethane.

4. The electric vehicle wireless charging device with a large transmission distance according to claim 3 is characterized in that: The secondary side device is packaged in a plastic shell.

5. A wireless charging pavement structure, characterized in that: The pavement structure is embedded with the primary device of the wireless charging device as described in any one of claims 1 to 4, and the pavement structure comprises, from top to bottom, an upper pavement layer, a primary device layer, a lower pavement layer, a road base layer and a road cushion layer.

6. A wireless charging pavement structure according to claim 5, characterized in that: The wireless charging primary device layer is arranged at the center line of each lane, embedded in the lower layer of the road surface, arranged adjacent to each other in sequence along the length direction of the lane, and connected to the power supply grid line; when the wireless charging primary device layer is arranged, the prefabricated cement concrete is first placed in the ditch of the road surface, and then the lower layer material of the road surface is poured to lay the road surface structure.

7. A wireless charging pavement structure according to claim 6, characterized in that: The upper layer, lower layer and road cushion layer of the road surface use conventional road surface materials; the road base layer uses a soil and stone roadbed that has been waterproofed.

Images