Design method of electric vehicle wireless charging station with high offset resistance

Abstract

The invention relates to the field of electric vehicle wireless charging station design, in particular to a design method of an electric vehicle wireless charging station with high offset resistance. According to the scheme, the method comprises the following steps: constructing a wireless charging single coil model and a Helmholtz coil model; setting emission current, and performing real-time comparative analysis on magnetic field distribution generated by the wireless charging single coil model and the Helmholtz coil model; changing the distance between the Helmholtz coils, and performing real-time analysis on the magnetic field distribution generated by the Helmholtz coil model; the emission current is changed, and the magnetic induction intensity distribution on the central horizontal plane of the Helmholtz coil is analyzed; according to the analysis result, obtaining the emission current, the coil spacing and the coil radius when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal; helmholtz coils are installed on the ground of a charging station and the top of a shed, and the Helmholtz coils are used to obtain emission current, coil spacing and coil radius. The method is suitable for the electric vehicle wireless charging station.

Description

Technical Field

[0001] The invention relates to the field of design of wireless charging stations for electric vehicles, and in particular to a design method of wireless charging stations for electric vehicles with strong anti-deviability. Background Art

[0002] New energy electric vehicles have little impact on the environment because they do not produce automobile exhaust and greenhouse gas emissions, which helps reduce air pollution and mitigate the greenhouse effect. Therefore, their development has positive significance for promoting national economic growth and promoting economic diversification. New energy electric vehicles can be mainly used in private applications, commercial transportation, and transportation. They can greatly reduce air pollution and improve air freshness, making them a more environmentally friendly choice. However, since new energy vehicles are not yet popular, many places do not have charging piles and their charging systems are not mature enough, which makes charging difficult and slow, and the driving range is short. The charging power and charging efficiency are always difficult to meet people's daily use requirements, which restricts the further use and development of new energy electric vehicles.

[0003] The main shortcomings of traditional wired charging technology are the hardware facilities for energy replenishment, the need to charge the car battery through cables, the problems of safety and reliability, the long charging time, and the inconvenience of long-distance self-driving tours. Wireless charging technology has the advantages of high safety, easy use, and high interface durability. Wireless charging transmits power through electromagnetic induction without direct contact with the power supply, which not only reduces safety hazards and makes operation more convenient, but also reduces the interface wear caused by frequent plugging and unplugging of charging cables, extending the service life of the device.

[0004] However, the misalignment of the receiving and transmitting coils of electric vehicles during parking is caused by the offset, which further reduces the charging efficiency. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a design method for an electric vehicle wireless charging station with strong anti-drift performance, thereby avoiding misalignment of the receiving and transmitting coils of the electric vehicle due to drift during parking and improving the charging efficiency.

[0006] The present invention adopts the following technical scheme to achieve the above-mentioned purpose. The present invention provides a design method of an electric vehicle wireless charging station with strong anti-deviability, comprising: S1. Construct a single coil model and a Helmholtz coil model for wireless charging; S2. Setting the transmitting current, and performing real-time comparative analysis on the magnetic field distribution generated by the single coil model of wireless charging and the Helmholtz coil model; S3, changing the spacing between the Helmholtz coils, and performing real-time analysis on the magnetic field distribution generated by the Helmholtz coil model; S4, changing the emission current, and analyzing the distribution of magnetic induction intensity on the horizontal plane at the center of the Helmholtz coil; S5. According to the analysis results of steps S2 to S4, the transmitting current, coil spacing and coil radius when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal are obtained; S6. Install Helmholtz coils on the ground of the charging station and on the top of the carport. The Helmholtz coils use step S5 to obtain the emission current, coil spacing, and coil radius.

[0007] Furthermore, in step S1, the radius r of the single coil and the Helmholtz coil is set to 1 meter, the number of turns is 10, and the distance between the single coil and the Helmholtz coil is 2 meters.

[0008] Furthermore, step S2 specifically includes: The transmitting current was set to 15 amperes, and the COMSOL software was used to conduct a real-time comparative analysis of the magnetic field distribution generated by the single coil model and the Helmholtz coil model of wireless charging.

[0009] Furthermore, step S3 specifically includes: The spacing between the Helmholtz coils is set to 2 meters, 3 meters, and 4 meters. By comparing and analyzing the corresponding magnetic field distribution diagrams, the effect of the coil spacing on the performance of wireless charging is obtained.

[0010] Furthermore, step S4 specifically includes: The emission current of the Helmholtz coil is set to 10 amperes, 15 amperes and 20 amperes, and the specific influence trend of the emission current on the magnetic induction intensity is obtained through the distribution of the magnetic induction intensity on the horizontal plane at the center of the Helmholtz coil under the corresponding conditions.

[0011] Furthermore, in step S5, the transmitting current when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal is 15 amperes, the coil spacing is 2 meters, and the coil radius is 1 meter.

[0012] Furthermore, the Helmholtz coil is composed of two coaxial circular coils with the same radius, current magnitude and direction. The current direction of the two coaxial circular coils is the same as the magnetic field direction. After the magnetic fields of the two coaxial circular coils are superimposed, the magnetic field direction always remains consistent.

[0013] The beneficial effects of the present invention are: The present invention constructs a single coil model and a Helmholtz coil model for wireless charging, sets a transmitting current, performs a real-time comparative analysis on the magnetic field distribution generated by the single coil model and the Helmholtz coil model for wireless charging, changes the spacing between the Helmholtz coils, performs a real-time analysis on the magnetic field distribution generated by the Helmholtz coil model, changes the transmitting current, analyzes the magnetic induction intensity distribution on the central horizontal plane of the Helmholtz coil, obtains the transmitting current, coil spacing and coil radius when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal, and finally installs the Helmholtz coil on the ground and the top of the carport of the charging station, the optimal transmitting current, coil spacing and coil radius used by the Helmholtz coil, and the Helmholtz coil is composed of two coaxial circular coils with the same radius, the same current magnitude and direction, the current direction of the two coaxial circular coils is the same as the magnetic field direction, and after the magnetic fields of the two coaxial circular coils are superimposed, the magnetic field direction remains consistent. Therefore, an effective way is provided to solve the problem of misalignment of the receiving-transmitting coil caused by offset during parking of electric vehicles, thereby significantly improving the charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of a method for designing a wireless charging station for electric vehicles with strong anti-deviation performance provided by an embodiment of the present invention; Figure 2 Schematic diagram of a Helmholtz coil model provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0015] 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.

[0016] The present invention provides a design method for an electric vehicle wireless charging station with strong anti-deviability. Figure 1 As shown, specifically including: S1. Construct a single coil model and a Helmholtz coil model for wireless charging; The present invention constructs two coil models of wireless charging systems through COMSOL software. In the single coil model, the radius r is set to 1 meter and the number of turns is determined to be 10. In the Helmholtz coil model, the radius r is also set to 1 meter and the number of turns is also selected to be 10. The spacing d between the two coils is 2 meters. Both models are set with uniform multi-turn coils.

[0017] S2. Setting the transmitting current, and performing real-time comparative analysis on the magnetic field distribution generated by the single coil model of wireless charging and the Helmholtz coil model; The transmitting current was set to 15 amperes, and the COMSOL software was used to conduct a real-time comparative analysis of the magnetic field distribution generated by the single coil model and the Helmholtz coil model of wireless charging.

[0018] When in the same position, the magnetic induction intensity on the axis of the Helmholtz coil shows a significant advantage over the single coil. Specifically, the magnetic induction intensity of the single coil shows a clear downward trend with the increase of the distance from the coil, and this change is quite significant. Relatively speaking, the Helmholtz coil not only produces a higher magnetic induction intensity on its axis, but also can form a region with high magnetic induction intensity, wide range and uniform distribution in the middle of the two coils. This feature makes the Helmholtz coil have a higher application value in wireless charging systems, especially in scenarios where large-scale, efficient and stable wireless charging is required.

[0019] S3, changing the spacing between the Helmholtz coils, and performing real-time analysis on the magnetic field distribution generated by the Helmholtz coil model; The present invention sets the transmitting current of a coil with 10 turns and a radius of 1 meter to 15 amperes, and sets the spacing between the upper and lower coils to 2 meters, 3 meters, and 4 meters, respectively. Under these conditions, the obtained magnetic field distributions are compared. By comparing and analyzing these magnetic field distribution diagrams, we can have a deeper understanding of the impact of the coil spacing on the performance of the wireless charging system, thereby providing an important basis for the optimal design of the system.

[0020] Reducing the distance between the two Helmholtz coils can effectively increase the magnetic induction intensity, but it will also lead to a decrease in the uniformity of the magnetic field. As the distance between the Helmholtz coils gradually decreases, the magnetic induction intensity on the central horizontal plane shows an increasing trend. However, as the spacing is further reduced, the uniformity of the magnetic induction intensity on the central horizontal plane shows a downward trend. In the case of comprehensively considering the balance between the magnetic induction intensity and the uniformity of the magnetic field, the present invention can conclude that the most suitable distance between the two coils is 2 meters, which can maintain a relatively high uniformity of the magnetic field while ensuring a strong magnetic induction intensity.

[0021] S4, changing the emission current, and analyzing the distribution of magnetic induction intensity on the horizontal plane at the center of the Helmholtz coil; The present invention sets a Helmholtz coil with 10 turns, a radius of 1 meter and a distance between two coils of 2 meters. On this basis, we set the emission current to 10 amperes, 15 amperes and 20 amperes respectively, and record the distribution of magnetic induction intensity on the horizontal plane at the center of the Helmholtz coil under the corresponding conditions. The specific influence trend of the emission current on the magnetic induction intensity can be obtained.

[0022] As the coil transmitting current gradually increases, the magnetic induction intensity generated on the horizontal plane at the center of the Helmholtz coil shows an increasing trend. However, this growth is not unlimited, because as the transmitting current further increases, the uniformity of the magnetic field generated on the horizontal plane at the center of the Helmholtz coil will also decrease accordingly. This phenomenon shows that when optimizing the performance of the wireless charging system, the present invention needs to comprehensively consider the balance between the magnetic induction intensity and the magnetic field uniformity to find the optimal transmitting current value. It can be seen that the coil transmitting current of 15 amperes is most suitable.

[0023] S5. According to the analysis results of steps S2 to S4, the transmitting current, coil spacing and coil radius when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal are obtained; After modeling the traditional single coil and Helmholtz coil models using COMSOL simulation software and analyzing and comparing them using MATLAB, it is concluded that the Helmholtz coil not only produces a higher magnetic induction intensity on its axis, but also can form a region with high magnetic induction intensity, wide range and uniform distribution in the middle of the two coils. This feature makes the Helmholtz coil have a higher application value in the wireless charging system. By analyzing the influence of the change of the structural parameters of the Helmholtz coil on the magnetic induction intensity, it is found that when the transmitting current of the wireless charging system is 15 amperes, the distance between the two transmitting coils is 2 meters, and the coil radius is 1m, the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal and the charging efficiency is the highest. The wireless charging station designed by the present invention can still maintain the charging efficiency of the electric vehicle even when the car is parked offset, proving the strong anti-offset property of the electric vehicle wireless charging station.

[0024] S6. Install Helmholtz coils on the ground of the charging station and on the top of the carport. The Helmholtz coils use step S5 to obtain the emission current, coil spacing, and coil radius.

[0025] To ensure the efficiency, safety and stability of the charging process, the size of the electric vehicle must be fully considered. According to the size parameters of common electric vehicles, the radius of the charging coil should be set to at least 1 meter to ensure sufficient charging coverage. At the same time, because the height of ordinary electric vehicles is about 1.6 meters, the distance between the two coils set at the bottom and top of the platform should be at least 2 meters.

[0026] like Figure 2As shown, the Helmholtz coil provided by the present invention has a common axis as the x-axis, and the y and z axes are perpendicular to the x-axis to form a right-hand system. The radius and spacing of the two coils are R, the number of turns is N, and a current I in the same direction is passed through them. The Helmholtz coil has extremely high magnetic field uniformity. Due to the unique structure and positioning method of the coil, the magnetic field strength and direction of the two coils are very uniform, thereby providing a magnetic field area with constant size and direction. Because the current directions of the two coils are the same, their magnetic field directions are also the same, so that after the magnetic fields of the two coils are superimposed, the magnetic field directions remain consistent. Therefore, the Helmholtz coil provides an effective way to solve the problem of misalignment of the receiving-transmitting coils caused by offset during parking of electric vehicles, thereby significantly improving the charging efficiency.

[0027] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A design method for an electric vehicle wireless charging station with strong anti-deviability, characterized in that: include: S1. Construct a single coil model and a Helmholtz coil model for wireless charging; S2. Setting the transmitting current, and performing real-time comparative analysis on the magnetic field distribution generated by the single coil model of wireless charging and the Helmholtz coil model; S3, changing the spacing between the Helmholtz coils, and performing real-time analysis on the magnetic field distribution generated by the Helmholtz coil model; S4, changing the emission current, and analyzing the distribution of magnetic induction intensity on the horizontal plane at the center of the Helmholtz coil; S5. According to the analysis results of steps S2 to S4, the transmitting current, coil spacing and coil radius when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal are obtained; S6. Install Helmholtz coils on the ground of the charging station and on the top of the carport. The Helmholtz coils use step S5 to obtain the emission current, coil spacing, and coil radius.

2. The method for designing a wireless charging station for electric vehicles with strong anti-deviability according to claim 1, characterized in that: In step S1 , the radius r of the single coil and the Helmholtz coil is set to 1 meter, the number of turns is 10, and the distance between the single coil and the Helmholtz coil is 2 meters.

3. The method for designing a wireless charging station for electric vehicles with strong anti-deviability according to claim 1, characterized in that: Step S2 specifically includes: The transmitting current was set to 15 amperes, and the COMSOL software was used to conduct a real-time comparative analysis of the magnetic field distribution generated by the single coil model and the Helmholtz coil model of wireless charging.

4. The method for designing a wireless charging station for electric vehicles with strong anti-deviability according to claim 1, characterized in that: Step S3 specifically includes: The spacing between the Helmholtz coils is set to 2 meters, 3 meters, and 4 meters. By comparing and analyzing the corresponding magnetic field distribution diagrams, the effect of the coil spacing on the performance of wireless charging is obtained.

5. The method for designing a wireless charging station for electric vehicles with strong anti-deviability according to claim 1, characterized in that: Step S4 specifically includes: The emission current of the Helmholtz coil is set to 10 amperes, 15 amperes and 20 amperes, and the specific influence trend of the emission current on the magnetic induction intensity is obtained through the distribution of the magnetic induction intensity on the horizontal plane at the center of the Helmholtz coil under the corresponding conditions.

6. The method for designing a wireless charging station for electric vehicles with strong anti-deviability according to claim 1, characterized in that: In step S5, the transmitting current when the magnetic induction intensity generated by the Helmholtz coil on the central horizontal plane is optimal is 15 amperes, the coil spacing is 2 meters, and the coil radius is 1 meter.

7. The method for designing a wireless charging station for electric vehicles with strong anti-deviability according to claim 1, characterized in that: The Helmholtz coil is composed of two coaxial circular coils with the same radius, current magnitude and direction. The current direction of the two coaxial circular coils is the same as the magnetic field direction. After the magnetic fields of the two coaxial circular coils are superimposed, the magnetic field direction always remains consistent.

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