A method for designing the spacing of wireless charging resonant coils for electric vehicles

Abstract

The present invention relates to the field of dynamic wireless power transmission technology, and more particularly to a method for designing the spacing of wireless charging resonant coils for electric vehicles. The energy transmitting coil and the energy receiving coil are designed as rectangular coils with the same width; when the road is a ramp, if the length of the energy receiving coil L s Not greater than the energy transmitting coil length L p When the spacing D between the energy transmitting coils is 1.25 times pri Designed to be 0; when the road is a slope, if the energy receiving coil length L s Greater than the energy transmitting coil length L p When the spacing D between the energy transmitting coils is 1.25 times pri The design is #imgabs0#, where #imgabs1#α is the slope of the ramp. According to different energy receiving coil sizes, different primary energy transmitting coil placement spacings are adopted on the ramp to ensure that the mutual inductance fluctuation rate is at a low level and the stability and efficiency of the transmission power are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic wireless power transmission, and in particular to a method for designing the placement spacing of wireless charging resonant coils for electric vehicles. Background Art

[0002] Traditional electric vehicle charging uses a wired plug-in charging mode, which causes equipment wear and aging during long-term outdoor operation, and manual operation of heavy equipment and high-voltage plugs also poses risks. As an emerging technology, wireless charging systems improve charging energy efficiency and work safety, and will gradually replace traditional plug-in wired charging.

[0003] The battery of electric vehicles is large in size, heavy in weight, low in energy density, long in charging time and short in life. It is difficult to achieve a breakthrough in battery energy storage technology in the short term, so dynamic wireless charging is generally adopted. This technology can supply energy to the energy receiving device during its movement by pre-laying an energy transmitting device under the route where the energy receiving device moves, greatly reducing the energy receiving device's demand for battery performance.

[0004] At present, in the segmented dynamic wireless power transmission system of wireless charging technology, an urgent problem to be solved is that the roads are complex during the driving of electric vehicles, the energy receiving device is in motion, and the relative positions between the transmission coils are often in a state of rapid and frequent changes, which will cause fluctuations in the mutual inductance between the transmission coils, thereby causing fluctuations in the output power of the wireless charging system. Summary of the invention

[0005] The purpose of the present invention is to address the defects of the prior art and provide a method for designing the placement spacing of electric vehicle wireless charging resonant coils. Starting from the energy coil placement spacing, different primary energy transmitting coil placement spacings are adopted on the ramp for different energy receiving coil sizes, thereby ensuring that the mutual inductance fluctuation rate is at a low level and ensuring the stability and efficiency of the transmission power.

[0006] The present invention provides a method for designing the placement spacing of wireless charging resonant coils for electric vehicles, and the technical solution is as follows:

[0007] The energy transmitting coil and the energy receiving coil are designed to be rectangular coils with the same width;

[0008] When the road is a slope, if the energy receiving coil length L s Not greater than the energy transmitting coil length L p When the spacing D between the energy transmitting coils is 1.25 times pri Design is 0;

[0009] When the road is a slope, if the energy receiving coil length L sGreater than the energy transmitting coil length L p When the spacing D between the energy transmitting coils is 1.25 times pri Designed for in, α is the slope of the ramp;

[0010] Also includes

[0011] When the road is curved, if the length of the energy receiving coil is L s Not greater than the energy transmitting coil length L p When the energy transmitting coils are 1.25 times of the original value, the angle difference θ between the energy transmitting coils is designed to be The distance between the energy transmitting coils is D pri Designed for

[0012] When the road is curved, if the length of the energy receiving coil is L s Greater than the energy transmitting coil length L p When the energy transmitting coils are 1.25 times of the original value, the angle difference θ between the energy transmitting coils is designed to be The distance between the energy transmitting coils is D pri Designed for Where r is the distance between the center of the energy transmitting coil and the center of the curve, W p is the width of the energy transmitting coil.

[0013] More preferably, it also includes

[0014] When the road is both curved and ramped, if the length of the energy receiving coil is L s Not greater than the energy transmitting coil length L p 1.25 times of the original value, and the angle difference θ between the energy transmitting coils is designed to be Set the distance D between the energy transmitting coils pri Designed for

[0015] When the road is both curved and ramped, if the length of the energy receiving coil is L s Greater than the energy transmitting coil length L p 1.25 times of the original value, and the angle difference θ between the energy transmitting coils is designed to be And according to the formula The larger value of is designed to design the spacing D between the energy transmitting coils pri .

[0016] Preferably, the energy transmitting coil and the energy receiving coil are wound in a plane spiral from outside to inside using multiple strands of Litz wire, and the magnetic flux directions of the primary coils of the energy transmitting coils are the same at the same time.

[0017] Preferably, the energy transmitting coil includes a first coil and a first ferrite core located above the first coil, and the energy receiving coil includes a second coil and a second ferrite core located above the second coil.

[0018] Preferably, the magnetic flux density of the ferrite core is lower than 0.3T.

[0019] Preferably, the width W of the energy transmitting coil is p In the range of 100mm~600mm, length L p In the range of 100mm to 600mm.

[0020] Preferably, the vertical distance between the energy transmitting coil and the energy receiving coil is in the range of 50 mm to 200 mm.

[0021] The beneficial effects of the present invention are:

[0022] 1. Based on the rectangular coil structure design, the mutual inductance value changes frequently and rapidly due to the movement of the coil under different road conditions, resulting in serious fluctuations in output power. Starting from the placement spacing of the coil, the energy transmitting coil placement spacing that minimizes the change in mutual inductance value under different energy receiving coil sizes is designed, so that the mutual inductance value fluctuation of the wireless energy receiving device is at a low level during the movement of the flat road or ramp, ensuring that the output power efficiency is optimized under the condition of magnetic field resonance transmission. In addition, the dynamic placement of the transmitting coil spacing in this method increases the gap between the emitter coils and reduces the amount of raw materials used. The spacing avoids the phenomenon that traditional dynamic wireless charging systems use a large number of raw materials such as coils, magnetic cores, and control boards. Maximize the transmission power at the lowest economic cost and reduce power loss.

[0023] 2. Based on the rectangular coil structure design, in order to solve the problem that the mutual inductance value changes frequently and rapidly due to the movement of the coil under different road conditions, resulting in serious fluctuations in the output power, starting from the coil placement angle offset, the energy transmitting coil placement angle that minimizes the change in mutual inductance value under different energy receiving coil sizes is designed, so that the mutual inductance value fluctuation of the wireless energy receiving device is at a low level during the movement of straight roads or curves, ensuring that the output power efficiency is optimized under the condition of magnetic field resonance transmission of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the energy transmitting coil of the present invention;

[0025] Figure 2 It is a schematic diagram of the energy receiving coil of the present invention;

[0026] Figure 3 A schematic diagram showing the relationship between the dimensions of the energy transmitting coil and the energy receiving coil of the present invention;

[0027] Figure 4 A schematic diagram for designing the spacing between energy transmitting coils when the road is a slope;

[0028] Figure 5 A schematic diagram showing the design of the angle difference between energy transmitting coils when the road is curved.

[0029] In the figure: 1-energy transmitting coil, 101-first coil, 102-first ferrite core, 2-energy receiving coil. , 201-second coil, 202-second ferrite core. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" means "two or more".

[0035] Embodiment 1

[0036] This embodiment provides a better method for designing the placement spacing of wireless charging resonant coils for electric vehicles, which is suitable for scenarios where both the energy transmitting coil and the energy receiving coil are rectangular coils. It is a method for designing the placement spacing of transmitting coils in a dynamic wireless charging system that takes road conditions into consideration. It takes into account complex road conditions. When passing through a ramp, the coil spacing is changed according to the slope α, and the placement spacing of the transmitting coils is determined according to different receiving coil lengths. When passing through a curve, the spacing is changed according to the difference in the curve angle θ, and the placement angle and spacing of the transmitting coils are determined according to different receiving coil lengths. The applicable wireless power transmission system transmitter and wireless power transmission system receiver have the same structure, both are rectangular coils, and are covered with ferrite cores on the back. The size of the ferrite is the same as the outer size of the rectangular coil, and the vertical distance between the energy transmission coils is in the range of 50mm to 200mm. The width W of the energy transmitting coil p In the range of 100mm~600mm, length L p In the range of 100mm to 600mm.

[0037] When the energy receiving coil is in a ramp motion state, the slope is α, the energy transmitting coils are placed side by side along the ramp angle, and the spacing between the energy transmitting coils is D pri ,definition:

[0038]

[0039] like Figures 1 to 3 As shown, the energy transmitting coil 1 includes a first coil 101 and a first ferrite core 102 located above the first coil 101 , and the energy receiving coil 2 includes a second coil 201 and a second ferrite core 202 located above the second coil 201 .

[0040] A method for designing the placement spacing of wireless charging resonant coils for electric vehicles is as follows:

[0041] The energy transmitting coil 1 and the energy receiving coil 2 are both designed to be rectangular coils with the same width;

[0042] like Figure 4 As shown, when the road is a slope, if the length of the energy receiving coil 2 is L s Not greater than the length L of the energy transmitting coil 1 p When the spacing D between the energy transmitting coils 1 is 1.25 times pri Design is 0;

[0043] When the road is a slope, if the length of the energy receiving coil 2 is L s Greater than the length L of the energy transmitting coil 1 p When the spacing D between the energy transmitting coils 1 is 1.25 times pri Designed for in, α is the slope of the ramp.

[0044] In one embodiment, it further includes:

[0045] When the road is curved, if the length of the energy receiving coil 2 is L s Not greater than the length L of the energy transmitting coil 1 p When the energy transmitting coils 1 are 1.25 times of the original value, the angle difference θ between the energy transmitting coils 1 is designed to be The distance D between the energy transmitting coils 1 pri Designed for

[0046] When the road is curved, if the length of the energy receiving coil 2 is L s Greater than the length L of the energy transmitting coil 1 p When the energy transmitting coils 1 are 1.25 times of the original value, the angle difference θ between the energy transmitting coils 1 is designed to be The distance D between the energy transmitting coils 1 pri Designed for Where r is the distance between the center of the energy transmitting coil 1 and the center of the curve, W p is the width of the energy transmitting coil.

[0047] In one embodiment, it further includes:

[0048] like Figure 5 As shown, when the road is both curved and ramped, if the length of the energy receiving coil 2 is L s Not greater than the length L of the energy transmitting coil 1 p 1.25 times of the energy transmitting coil 1, the placement angle difference θ is designed to be The distance D between the energy transmitting coils 1 pri Designed for

[0049] When the road is both curved and ramped, if the length of the energy receiving coil 2 is L s Greater than the length L of the energy transmitting coil 1 p 1.25 times of the energy transmitting coil 1, the placement angle difference θ is designed to be And according to the formula The larger value of is designed to design the distance D between the energy transmitting coils 1 pri .

[0050] In one embodiment, the energy transmitting coil 1 and the energy receiving coil 2 are wound in a plane spiral from outside to inside using multiple strands of Litz wire, and the placement direction of the energy transmitting coil needs to be kept consistent to ensure that the magnetic flux direction generated in the primary coil of the energy transmitting coil 1 is the same at the same time.

[0051] In one embodiment, the magnetic flux density of the ferrite core is lower than 0.3T.

[0052] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0053] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0054] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0055] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including" is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0056] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for designing the spacing of wireless charging resonant coils for electric vehicles. Features: The energy transmitting coil (1) and the energy receiving coil (2) are both designed to be rectangular coils with the same width; When the road is a slope, if the length of the energy receiving coil (2) is L s Not greater than the length L of the energy transmitting coil (1) p When the spacing D between the energy transmitting coils (1) is 1.25 times of pri Design is 0; When the road is a ramp, if the length L of the energy receiving coil (2) s is greater than 1.25 times the length L of the energy transmitting coil (1) p the spacing D between the energy transmitting coils (1) is designed to be pri wherein α is the slope of the ramp; ​ Also includes When the road is curved, if the length of the energy receiving coil (2) is L s Not greater than the length L of the energy transmitting coil (1) p When the energy transmitting coils (1) are 1.25 times larger, the placement angle difference θ between the energy transmitting coils (1) is designed to be The distance D between the energy transmitting coils (1) pri Designed for When the road is curved, if the length of the energy receiving coil (2) is L s Greater than the length L of the energy transmitting coil (1) p When the energy transmitting coils (1) are 1.25 times larger, the placement angle difference θ between the energy transmitting coils (1) is designed to be The distance D between the energy transmitting coils (1) pri Designed for Where r is the distance between the center of the energy transmitting coil (1) and the center of the curve, W p is the width of the energy transmitting coil.

2. The method for designing the placement spacing of the wireless charging resonant coils for electric vehicles according to claim 1, Features: Also includes When the road is both curved and ramped, if the length of the energy receiving coil (2) is L s Not greater than the length L of the energy transmitting coil (1) p 1.25 times of the energy transmitting coils (1), the placement angle difference θ between the energy transmitting coils (1) is designed to be The distance D between the energy transmitting coils (1) is pri Designed for When the road is both curved and ramped, if the length of the energy receiving coil (2) is L s Greater than the length L of the energy transmitting coil (1) p 1.25 times of the original value, the placement angle difference θ between the energy transmitting coils (1) is designed to be And according to the formula The larger value of is designed to design the spacing D between the energy transmitting coils (1) pri .

3. The method for designing the placement spacing of wireless charging resonant coils for electric vehicles according to claim 1, Features: The energy transmitting coil (1) and the energy receiving coil (2) are wound in a plane spiral from outside to inside using multiple strands of Litz wire, and the magnetic flux directions generated in the primary coils of the energy transmitting coil (1) at the same time are the same.

4. The method for designing the placement spacing of wireless charging resonant coils for electric vehicles according to claim 1, Features: The energy transmitting coil (1) comprises a first coil (101) and a first ferrite core (102) located above the first coil (101), and the energy receiving coil (2) comprises a second coil (201) and a second ferrite core (202) located above the second coil (201).

5. The method for designing the placement spacing of wireless charging resonant coils for electric vehicles according to claim 4, Features: The magnetic flux density of the ferrite core is lower than 0.3T.

6. The method for designing the placement spacing of wireless charging resonant coils for electric vehicles according to claim 1, Features: The width W of the energy transmitting coil (1) p In the range of 100mm~600mm, length L p In the range of 100mm to 600mm.

7. The method for designing the placement spacing of wireless charging resonant coils for electric vehicles according to claim 1, Features: The vertical distance between the energy transmitting coil (1) and the energy receiving coil (2) is within the range of 50 mm to 200 mm.

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