Electric vehicle wireless charging system based on magnetic coupling resonance mode

Abstract

The invention discloses an electric vehicle wireless charging system based on a magnetic coupling resonant mode. An electric vehicle comprises a driving motor and a power storage battery. A receiving coil is arranged on a chassis of the electric automobile; a power transmission guide rail is arranged below the road surface of a road where the electric vehicle runs in the running direction of the electric vehicle and connected with a public power grid through a primary electric energy conversion facility, and electric energy is provided by the public power grid. By adopting the technical scheme and applying the magnetic coupling resonant wireless power transmission technology, the electricity storage capacity of the storage battery does not need to be further improved, meanwhile, the potential safety hazard of the battery is reduced, the utilization rate of the automobile battery is improved, and the manufacturing cost of the automobile is reduced; the efficient wireless charging technology of the long-distance electric vehicle avoids environmental pollution caused by insufficient fuel oil of a fuel oil vehicle, and has a wide market prospect, so that the purposes of energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicle charging. More specifically, the present invention relates to an electric vehicle wireless charging system based on magnetic coupling resonance. Background Art

[0002] With the development of science and technology and the growth of social demand, the electric vehicle industry and market have developed rapidly. However, the corresponding services have not followed up in a timely manner, and problems such as difficulty in parking and charging are very prominent.

[0003] The increasing market share of electric vehicles is due to the support of national policies.

[0004] In terms of braking and handling performance, electric vehicles are also far superior to fuel vehicles. Braking and handling performance mainly test the brake system and chassis. In fact, there is no essential difference between fuel vehicles and electric vehicles for these two systems. However, since the motor has a powerful reverse energy conversion function (that is, converting kinetic energy back into electrical energy), it can provide an additional braking force while braking, so the braking performance is more advantageous. In addition, since the huge battery of electric vehicles is installed at the bottom of the vehicle body, the center of gravity of the entire vehicle is lower, which is more conducive to control and vehicle stability.

[0005] With the increasing number of cars, the problems of difficulty in charging cars and battery life are becoming more and more serious.

[0006] The "distance trouble" that electric vehicles bring to people today is a major factor slowing down their development. The main reason for this problem is that the energy density of batteries that can be manufactured with existing technology is slowly increasing, which makes the driving distance of electric vehicles limited. Battery replacement technology is also not popularized due to its high price, which brings great trouble to consumers.

[0007] In the case that the existing technology cannot improve the battery energy density, the best way to solve the "mileage problem" is to use indirect charging mode to solve the short range of electric vehicles. With the continuous attention of car companies and the country, I believe that we will soon see the full application of wireless charging technology.

[0008] Using keywords such as "electric vehicle; wireless charging; electromagnetic induction; mobile charging" to search existing public technical literature, the following search results were obtained:

[0009] 1. Chinese patent document: "A vehicle-mounted wireless charging system for electric vehicles", patent (application) number: 201810871618.3; the technical solution recorded is:

[0010] "The underbody wireless charging system for electric vehicles includes a power part, a mobile charging platform, an air pressure control part, and a wireless charging receiving part located at the bottom of the electric vehicle. The wireless charging receiving part includes a wireless charging receiving coil, and permanent magnets are arranged at the four corners of the wireless charging receiving coil; a wireless charging transmitting coil is arranged on the top of the mobile charging platform, and magnetic field sensors corresponding to the permanent magnets are arranged at the four corners. The power part is connected to the mobile charging platform through a connecting rod, and the air pressure control part is connected to the mobile charging platform through an air pressure pipeline. The wireless charging receiving coil and the wireless charging transmitting coil exchange energy through electromagnetic induction, and transfer the electric energy in the charging station to the car battery";

[0011] The technical effects recorded are:

[0012] "This wireless charging system not only provides a new technical reference for high-efficiency wireless charging of electric vehicles in the future, but also prevents the impact of wireless charging of electric vehicles on the surrounding environment."

[0013] 2. Chinese patent document: "A method for passive automatic wireless charging of a ground mobile charging device", patent (application) number: 202110631479.9; the technical solution recorded is:

[0014] “The passive automatic wireless charging mode only requires the installation of a charging transmitter at one end of the charging pile, and uses image recognition and rangefinder technology to achieve high-precision docking between the mobile charging device and the charging pile”;

[0015] The technical effects recorded are:

[0016] "It can complete efficient and automated wireless charging of ground mobile charging equipment."

[0017] However, the technical solutions recorded in the above technical documents and the related technical solutions currently in public use have not been able to solve the problems and defects of the difficulty in charging electric vehicles in the prior art. Summary of the invention

[0018] The present invention provides a wireless charging system for an electric vehicle based on magnetic coupling resonance, the purpose of which is to realize long-distance and efficient wireless charging of the electric vehicle during driving.

[0019] In order to achieve the above object, the technical solution adopted by the present invention is:

[0020] The present invention is a wireless charging system for electric vehicles based on magnetic coupling resonance. The electric vehicle comprises a driving motor and a power storage battery. A receiving coil is arranged on the chassis of the electric vehicle. A transmission rail is arranged below the road surface on which the electric vehicle travels and along the direction in which the electric vehicle travels. The transmission rail is connected to a public power grid through a primary power conversion facility, and electric energy is provided by the public power grid.

[0021] The receiving coil is input into the driving motor and the power battery respectively after being rectified and stabilized by the voltage circuit.

[0022] Furthermore, transmitting coils are continuously arranged along the direction of vehicle travel, and each of the transmitting coils is connected to the power transmission rail through a power line.

[0023] Over the entire length of the electric vehicle driving road, the transmission rail is divided into a plurality of independent rail sections, and the transmitting coils are evenly distributed on each rail section; each rail section is connected to the public power grid via a primary power conversion facility.

[0024] A proximity induction switch is arranged on the power line connecting each transmitting coil and the power transmission rail.

[0025] Along the entire length of the electric vehicle driving road, the guide rail section is divided into multiple guide rail groups, each guide rail group is connected to the public power grid through an electric energy conversion device; each guide rail group includes multiple guide rail sections; each guide rail section is connected to the electric energy conversion device of the corresponding guide rail group through a commutation switch and a resonant compensator.

[0026] The primary electric energy conversion facility passes through an industrial frequency rectifier and a high-frequency inverter, and then converts the high-frequency current into a high-frequency magnetic field through a transmitting coil, and a high-frequency current is induced by a receiving coil.

[0027] The wireless charging system uses the positioning device on the electric vehicle to realize big data analysis of road traffic conditions and provide the best route for drivers and passengers.

[0028] The wireless charging system is combined with the Internet of Vehicles to achieve network connection between different electric vehicles and between electric vehicles and road pavement facilities, provide real-time road condition data for electric vehicles, and provide full and strong support for autonomous driving.

[0029] The present invention adopts the above technical solution and uses magnetic coupling resonant wireless power transmission technology. There is no need to further improve the storage capacity of the battery, while reducing the safety hazards of the battery, improving the utilization rate of the vehicle battery, and reducing the manufacturing cost of the vehicle; the efficient long-distance electric vehicle wireless charging technology avoids the environmental pollution caused by insufficient fuel in fuel vehicles, and has broad market prospects, thereby achieving the purpose of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The contents shown in the attached drawings and the symbols in the drawings are briefly described as follows:

[0031] Figure 1 This is a schematic diagram of the structure of the single-stage rail charging mode adopted in the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of the multi-level rail charging mode adopted in the present invention;

[0033] Figure 3 for Figure 2 A schematic diagram of the rail circuit for the charging mode shown;

[0034] Figure 4 This is a schematic diagram of the structure of the double-layer multi-level rail charging mode adopted in the present invention;

[0035] Figure 5 It is a circuit schematic diagram of the electric energy conversion of the present invention.

[0036] The markings in the figure are:

[0037] 1. Electric vehicle, 2. Road surface, 3. Driving motor, 4. Energy conversion and control unit, 5. Power battery, 6. Receiving coil, 7. High-frequency magnetic field, 8. Primary power conversion facility, 9. Public power grid, 10. Transmission rail, 11. Transmitting coil, 12. Rail section, 13. Rail assembly. DETAILED DESCRIPTION

[0038] The specific implementation modes of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0039] like Figures 1 to 5 The structure of the present invention is a wireless charging system for electric vehicles based on magnetic coupling resonance, wherein the electric vehicle 1 comprises a driving motor 3 and a power battery 5. Wireless charging technology originates from wireless power transmission technology, and uses magnetic resonance to transmit charge in the air between the charger and the device, and the coil and the capacitor form resonance between the charger and the device to achieve efficient transmission of electric energy.

[0040] Wireless charging technology is a choice under the rapid development of the times and technology. Wireless charging or wireless power supply technology is a technology that uses radio waves or electromagnetic fields as carriers to charge power batteries in free space. Compared with the direct contact charging technology widely used in existing technologies, wireless charging technology can not only reduce or even save the cost of direct connection devices such as power cords, but also cleverly avoid wear or electric shock caused by repeated plugging and unplugging of wires during use, and embody multiple characteristics such as freedom, convenience, efficiency and safety in power transmission; wireless charging technology has the characteristics of high adaptability, high reliability and high safety when transmitting energy, and will not be affected by changes in the external environment, and can meet people's needs for car charging in today's rapidly developing cities.

[0041] With the continuous development of wireless charging technology and supporting industries, both buses and small family cars will continue to develop with the goal of high efficiency, versatility, intelligence, integration, and networking. After decades of discovery, wireless charging technology is now moving towards commercialization. High-efficiency and intelligent wireless charging technology has gradually become the mainstream of development and has become an indispensable technology for autonomous driving and automatic parking.

[0042] 1. Wireless charging mode of the present invention:

[0043] The guide rail mode of the electric vehicle wireless charging system of the present invention is divided into a single-stage guide rail charging mode and a multi-stage guide rail charging mode, which are described in detail as follows:

[0044] 1. Single-stage rail charging mode:

[0045] In order to solve the problems existing in the prior art and overcome its defects, and realize the invention purpose of long-distance and efficient wireless charging of electric vehicles during driving, the technical solution adopted by the present invention is:

[0046] like Figure 1 and Figure 2 As shown, the magnetically coupled resonance-based wireless charging system for electric vehicles of the present invention has a receiving coil 6 disposed on the chassis of the electric vehicle 1; a transmission rail 10 is disposed below a road surface 2 on which the electric vehicle 1 is traveling and along the direction in which the electric vehicle 1 is traveling, and the transmission rail 10 is connected to a public power grid 9 via a primary power conversion facility 8, and the public power grid 9 provides power.

[0047] Furthermore, if Figure 2 As shown, the transmitting coils 11 are continuously arranged along the direction of vehicle travel, and each of the transmitting coils 11 is connected to the power transmission rail 10 through a power line.

[0048] For the single-stage rail charging mode, when the system is working, there is only one rail and one set of primary power conversion devices in the primary circuit. Figure 1 , Figure 2 shown.

[0049] The present invention provides a vehicle that can realize contactless charging of electric vehicles while driving, solving the endurance problem of pure electric vehicles. Mainly based on the principle of magnetic coupling resonant wireless power transmission, the electric vehicle is charged contactlessly. The magnetic coupling resonant wireless power transmission system is mainly composed of four parts: power circuit, communication, control and control coil. By using the resonance principle, two or more transmitting coils and receiving coils with the same resonant frequency resonate at a specific power supply frequency, thereby achieving the purpose of medium-distance wireless power transmission.

[0050] The present invention utilizes a magnetic coupling resonant wireless power transmission system, and can continue to use the current battery technology, without the need for further research and development of the battery's power storage capacity, while reducing the potential safety hazards of the battery, improving the utilization rate of the car battery, and reducing the cost of car manufacturing. The use of electric vehicles can avoid environmental pollution caused by insufficient fuel, save 27 billion degrees of electricity each year, and reduce carbon dioxide emissions by 40 million tons, which has a large market, thereby achieving the effect of energy conservation and emission reduction.

[0051] When the resonant coil parameters resonate, the system has a higher energy transmission efficiency and can achieve efficient power transmission over medium distances while ensuring a higher transmission efficiency. This technical solution also ensures the transmission efficiency of wireless charging of electric vehicles.

[0052] A large number of transmitting coils connected to the high-frequency current of the power grid are laid on the road surface. The current is changed through power conversion control - magnetic coupling transformer, which then charges the electric vehicles.

[0053] A receiving coil is installed at the bottom of the vehicle body, which is connected to the vehicle's drive device through a coupling transformer, a control unit, a diode, a temperature control conductor, and a parameter identification device to realize wireless charging of the electric vehicle. A thermostat and a pressure sensor are also required to be installed on the road surface to monitor the impact of temperature and vehicle weight on the transmitting coil in real time.

[0054] The advantages of the single-stage rail charging mode are: simple structure, easy control and maintenance.

[0055] However, since the guide rail structure is a single long guide rail, it also has the following disadvantages:

[0056] (1) When the number of cars running on the guide rail is small, the transmission efficiency of the system will decrease;

[0057] (2) The system is not stable enough and is sensitive to parameter changes. Any slight parameter change may cause the system to fail to operate stably.

[0058] 2. Multi-level rail charging mode:

[0059] The multi-level rail charging mode is specifically divided into a single-layer multi-level rail charging mode and a double-layer multi-level rail charging mode, where:

[0060] (1) Single-layer multi-level rail charging mode:

[0061] like Figure 3 As shown, over the entire length of the road on which the electric vehicle 1 travels, the transmission rail 10 is divided into a plurality of independent rail sections 12, and the transmitting coils 11 are evenly distributed on each rail section 12; each of the rail sections 12 is connected to the public power grid 9 via a primary power conversion facility 8.

[0062] For the single-layer multi-level rail charging mode, when the system is working, there are multiple rails and multiple sets of power conversion devices in the primary coil. When the electric vehicle drives onto a rail, the rail will supply power to the electric vehicle, and the other rails are in standby state. Figure 3 shown.

[0063] When the car travels to the next section of the guide rail, the previous section of the guide rail is turned off and the next section of the guide rail is turned on to supply power to the electric car.

[0064] In the single-layer multi-level rail charging mode, the system power supply rail is divided into N sections, each of which is equipped with its own power conversion device, resonance compensation device and commutation switch, such as Figure 3 As shown. The electric energy is output from the power grid, and the power frequency AC is converted into high-frequency AC through the power conversion device of each power supply rail. It is injected into the resonant compensation network under the control of the commutation switch, and a high-frequency excitation current is generated in each power supply rail. Finally, the energy is transmitted to the secondary circuit of the system through the coupling mechanism.

[0065] Depend on Figure 3 It can be seen that the single-layer multi-level rail charging mode has the following advantages:

[0066] 1) It realizes the time-sharing power supply of multi-level guide rails and improves the transmission efficiency of the system;

[0067] 2) When a certain section of the guide rail fails, it does not affect the normal operation of other guide rails;

[0068] 3) Reduce the system's sensitivity to parameter changes and improve the system's stability;

[0069] However, this single-layer multi-level rail charging mode also has some problems:

[0070] If the guide rail length is designed to be very short, the system loss can be greatly reduced and the system transmission efficiency can be improved. However, due to the addition of many power conversion devices, the difficulty of system control and maintenance is increased, and the stability of the system is reduced;

[0071] If the guide rail length is designed to be longer, the number of electric energy conversion devices can be greatly reduced, but the single-unit capacity of the electric energy conversion device increases, and higher requirements are placed on electronic devices; at the same time, the system's sensitivity to parameter changes is increased, and the system's stability is reduced.

[0072] (2) Double-layer multi-level rail charging mode:

[0073] like Figure 4As shown, over the entire length of the road on which the electric vehicle 1 travels, the guide rail segment 12 is divided into a plurality of guide rail groups 13, each guide rail group 13 is connected to the public power grid 9 via an electric energy conversion device; each guide rail group 13 includes a plurality of guide rail segments 12; each guide rail segment 12 is connected to the electric energy conversion device of the corresponding guide rail group 13 via a commutation switch and a resonant compensator.

[0074] On the basis of the single-layer multi-level rail charging mode, several rail groups are set, and each rail group is provided with several rail sections; in each rail group there is only one set of power conversion device which converts industrial frequency alternating current into high-frequency alternating current and then injects it into the power supply rail.

[0075] Each guide rail group is divided into n small guide rail sections, each of which is equipped with its own resonance compensation device and commutation switch. They adaptively switch to the guide rail power supply state according to their own load conditions, thus realizing hierarchical control of double-layer multi-level guide rails.

[0076] The double-layer multi-level rail charging mode has the following advantages:

[0077] 1) It realizes the time-sharing and segmented power supply of the guide rail, reduces system loss and improves system transmission efficiency;

[0078] 2) The number of electric energy conversion devices is small, which is easy to control and maintain;

[0079] 3) The power level of the electric energy conversion device is small, which reduces the requirements for electronic devices;

[0080] 4) Reduces the system's sensitivity to parameter changes and improves system stability.

[0081] 2. The specific structure of the wireless charging system:

[0082] The electric vehicle wireless charging system based on magnetic coupling resonance of the present invention comprises a built-in receiving coil of the vehicle and a transmitting coil of the road. It also comprises a driving device, a control unit, etc. Figure 5 shown.

[0083] Contactless charging is based on magnetic coupling resonant contactless power transmission technology. The magnetic coupling resonant wireless power transmission system is mainly composed of four parts: power circuit, communication, control and power coil. The public power grid provides power, and the rectifier inverter circuit on the power supply side provides high-frequency AC power to the transmitting coil. The energy is injected into the transmitting coil after passing through the compensation network; the receiving coil in the electric vehicle is then converted into power, and the parameters are identified, and then transmitted to the control unit for supply to different loads.

[0084] The receiving coil 6 is input into the driving motor 3 and the power battery 5 respectively through the rectification and voltage stabilization circuit.

[0085] In addition to the core systems mentioned above, a series of auxiliary systems such as foreign object detection and coil positioning have been developed to ensure the safety and reliability of core power transmission.

[0086] The driving device is powered by a battery pack to drive the electric vehicle. The electric vehicle has a large number of built-in signal sensors. The signal processing system selects the required parameters and compares them with the built-in parameters to achieve signal feedback. The control unit realizes the battery charging and discharging process.

[0087] The primary power conversion facility 8 passes through an industrial frequency rectifier and a high-frequency inverter, and then converts the high-frequency current into a high-frequency magnetic field through a transmitting coil 11, and the receiving coil 6 induces a high-frequency current.

[0088] A proximity induction switch is provided on the power line connecting each transmitting coil 11 and the power transmission rail 10 .

[0089] Through the proximity induction switch, when the electric vehicle, that is, the receiving coil, approaches the transmitting coil, the transmitting coil 11 circuit is connected to realize time-divided power supply.

[0090] The wireless charging system uses the positioning device on the electric vehicle 1 to perform big data analysis on road traffic conditions and provide the best route for the driver and passengers.

[0091] The wireless charging system is combined with the Internet of Vehicles to achieve network connection between different electric vehicles 1 and between the electric vehicle 1 and the road surface 2 facilities, providing real-time road condition data for the electric vehicle 1 and providing full and strong support for autonomous driving.

[0092] The positioning device on the car can analyze the traffic situation through big data to provide the driver with the best route. At the same time, electric vehicles combined with the Internet of Vehicles can achieve network connection between cars and cars and road facilities, providing real-time road condition data for cars and providing powerful conditions for autonomous driving.

[0093] The intelligence of wireless charging technology includes intelligent optimization of the power receiving device and the charging device. For example, the battery can be automatically diagnosed and troubleshooted during charging, as well as the battery power management. At the same time, wireless charging electric vehicles can be driven and charged automatically through the positioning device of the wireless charging device. For public parking spaces, the parking space can be automatically moved out when charging is completed to be used by the next electric vehicle ready for charging.

[0094] 3. Working principle and performance analysis of the present invention:

[0095] The principle of magnetic coupling wireless charging technology is that the power of the power grid is transmitted in the form of electric power between the primary and secondary induction coils inside and outside the car in the form of magnetic field coupling. The biggest feature of this technology is that it can transmit energy at a higher frequency.

[0096] The present invention mainly performs contactless charging of electric vehicles based on the principle of magnetically coupled resonant wireless power transmission. The magnetically coupled resonant wireless power transmission system is mainly composed of four parts: power circuit, communication, control and control coil. By utilizing the resonance principle, two or more transmitting coils and receiving coils with the same resonant frequency resonate at a specific power supply frequency, thereby achieving the purpose of medium-distance wireless power transmission.

[0097] In the present invention, a receiving coil is installed in the electric vehicle, which is arranged at the chassis of the electric vehicle, and generates mutual induction with the transmitting coil in the road, and realizes contactless charging through the change of magnetic flux in the two coils. When the resonant coil parameters resonate, the system has a higher energy transmission efficiency, can realize efficient power transmission in medium distance, and can ensure a higher transmission efficiency.

[0098] To achieve continuous high-efficiency power transmission to shorten charging time, it is necessary to analyze the heat dissipation performance of the equipment and the utilization rate of the power grid and study the response strategy. At the same time, it is also necessary to solve the problem of small transmission area of ​​a single transmission device and high docking accuracy of the receiving device and the transmission device in the development of dynamic wireless charging.

[0099] The high-power wireless charging roads currently under trial need to be equipped with special wireless charging systems. The charging performance of different wireless charging systems is not exactly the same. However, as the wireless charging pavement technology matures, different power receiving devices and different power transmission devices will not match each other in actual applications. Therefore, in the development of wireless charging, attention should be paid to the compatibility between different systems.

[0100] 4. Analysis of the innovation and application prospects of the present invention:

[0101] The innovative features and positive effects of the present invention are as follows:

[0102] 1. Adopting the basic principle of magnetic coupling resonance, the transmitter converts electrical energy into relay energy in the form of a magnetic field. After transmitting it over a certain distance, the receiver converts the relay energy into electrical energy to realize wireless charging of the electric vehicle power supply.

[0103] 2. The power transmission components are not exposed and will not be corroded by moisture or oxygen in the air; the charging components are not in contact, so there will be no loss or potential failure caused by wear and sparking during connection and separation;

[0104] 3. The magnetic coupling resonant wireless power transmission system can continue to use the current battery technology without further improving the battery storage capacity. At the same time, it reduces the potential safety hazards of the battery, improves the utilization rate of the car battery, and reduces the vehicle manufacturing cost;

[0105] 4. Non-contact, one-to-many charging greatly reduces the potential safety hazards caused by poor contact due to frequent plugging and unplugging of data cables;

[0106] 5. Improve the manufacturing process of electric vehicle charging device components, reduce costs by about 20% to 30%, explore and develop contactless charging devices using inductive materials, and improve the endurance of electric vehicles.

[0107] Application prospect analysis of the present invention:

[0108] The wireless charging system of the present invention implements the concepts of energy conservation, environmental protection, sustainable development and low-carbon life, and is mainly aimed at transforming and utilizing the energy storage device of the automobile with long-term endurance, so as to construct an innovative wireless charging electric vehicle.

[0109] The charging system not only saves more energy for the car, but also greatly improves the durability and safety of the car during operation. At the same time, this product reduces material costs, saves resources, and can be widely used in today's electric vehicles.

[0110] The system is very stable and efficient in terms of both battery life and energy storage. It can improve the vehicle's electrical economy and fuel economy, increase the vehicle's range, reduce vehicle operating costs, and reduce exhaust emissions. It is in line with the current trend of energy conservation and emission reduction, so it has broad application prospects both at home and abroad.

[0111] V. Specific control technology involved in the present invention:

[0112] 1. Energy transmission robust control technology:

[0113] In terms of dynamic wireless power transmission control technology, there are three main methods: primary side control, secondary side control and bilateral control. The method of controlling the primary side resonant current by adjusting the duty cycle of the inverter drive signal simplifies the system structure.

[0114] In system design, primary-side constant current control is adopted, that is, a DC / DC converter is added to the front end of the inverter, and the inverter output constant current control is achieved by adjusting the primary DC bus voltage. The purpose of primary-side control is mainly to generate a constant alternating magnetic field on the power supply rail, thereby achieving robust control of the output power.

[0115] The dual-parameter synchronous control method of power and maximum efficiency without bilateral communication achieves maximum efficiency control by adjusting the equivalent AC impedance of the secondary side of the DC / DC converter, and achieves output constant power control by searching for the minimum value of the primary side input power.

[0116] For the robust control strategy of dynamic wireless power transmission, the PI control algorithm is generally used, and the control parameters are generally selected through the pole configuration method, which is relatively simple and easy to implement.

[0117] However, existing modeling and control research usually ignores the various uncertain disturbance information in the actual application of dynamic wireless power supply for electric vehicles. The dynamic response characteristics of the system and the design of fast and robust controllers under multi-parameter disturbances need further research.

[0118] 2. Electromagnetic compatibility technology:

[0119] Dynamic wireless power transmission uses high-frequency and strong magnetic fields to achieve wireless transmission of electrical energy. Its own operating frequency is high and the electromagnetic environment is complex. Therefore, electromagnetic compatibility design is an important content, which specifically includes magnetic shielding design, frequency configuration, grounding design, residual magnetism design, software anti-interference design, etc.

[0120] The electromagnetic interference suppression of wireless power transmission in electric vehicles can be divided into two categories: active shielding and passive shielding.

[0121] In terms of passive shielding, ferromagnetic materials are mainly used to provide an alternative path for magnetic flux or to use low magnetic permeability metal conductor materials to generate a magnetic field opposite to the leakage magnetic field. The use of ferromagnetic materials can improve the self-inductance and mutual inductance coefficients of the magnetic coupling coil, and further optimize the spatial distribution constraints of the magnetic field on the basis of enhancing the coupling performance. The magnetic circuit loss is small, but the shielding effect is limited. Metal shielding is widely used in radio frequency occasions to suppress high-frequency magnetic field electromagnetic interference. In terms of magnetic shielding of metal conductor materials, low magnetic permeability metal conductors are used to reduce electromagnetic interference. The advantages of this solution are simple design and easy operation, but its limitations are that it cannot cover the entire transmitting coil and receiving coil. The exposure and wear of the conductive material on the ground and the eddy current loss directly affect the performance of the system.

[0122] In terms of active shielding, an active or passive active shielding coil is placed near the coupling mechanism to generate a canceling magnetic field, which occupies less space than metal shielding. The active magnetic field cancellation method of adding a resonant coil is adopted, and a resonant passive active shielding scheme with double coils and phase adjustment is implemented. The shielding coil is placed on one side of the coupling mechanism, and an induced current is generated through the leakage magnetic field to generate a canceling magnetic field opposite to the original magnetic field, thereby realizing the magnetic shielding function.

[0123] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A wireless charging system for electric vehicles based on magnetic coupling resonance, wherein the electric vehicle (1) comprises a drive motor (3) and a power storage battery (5), and is characterized in that: A receiving coil (6) is arranged on the chassis of the electric vehicle (1); a power transmission rail (10) is arranged below the road surface (2) on which the electric vehicle (1) is traveling and along the direction in which the electric vehicle (1) is traveling; the power transmission rail (10) is connected to a public power grid (9) via a primary power conversion facility (8), and electric energy is provided by the public power grid (9).

2. The wireless charging system for electric vehicles based on magnetic coupling resonance according to claim 1, characterized in that: The receiving coil (6) is input into the driving motor (3) and the power storage battery (5) respectively after passing through the rectification and voltage stabilization circuit.

3. The wireless charging system for electric vehicles based on magnetic coupling resonance according to claim 1 or 2, characterized in that: Transmitting coils (11) are arranged continuously along the direction of vehicle travel, and each of the transmitting coils (11) is connected to a power transmission rail (10) via a power line.

4. The electric vehicle wireless charging system based on magnetic coupling resonance according to claim 3 is characterized in that: Over the entire length of the road on which the electric vehicle (1) travels, the power transmission rail (10) is divided into a plurality of mutually independent rail sections (12), and the transmitting coils (11) are evenly distributed on each rail section (12); each rail section (12) is connected to a public power grid (9) via a primary power conversion facility (8).

5. The electric vehicle wireless charging system based on magnetic coupling resonance according to claim 3 is characterized in that: A proximity induction switch is provided on the power line connecting each transmitting coil (11) and the power transmission rail (10).

6. The wireless charging system for electric vehicles based on magnetic coupling resonance according to claim 4, characterized in that: Over the entire length of the road on which the electric vehicle (1) travels, the guide rail section (12) is divided into a plurality of guide rail groups (13), each guide rail group (13) being connected to a public power grid (9) via an electric energy conversion device; each guide rail group (13) includes a plurality of guide rail sections (12); and each guide rail section (12) is connected to the electric energy conversion device of the corresponding guide rail group (13) via a commutation switch and a resonant compensator.

7. The electric vehicle wireless charging system based on magnetic coupling resonance according to claim 1 is characterized in that: The primary electric energy conversion facility (8) passes through an industrial frequency rectifier and a high-frequency inverter, and then converts the high-frequency current into a high-frequency magnetic field through a transmitting coil (11), and the high-frequency current is induced by a receiving coil (6).

8. The electric vehicle wireless charging system based on magnetic coupling resonance according to claim 1 is characterized in that: The wireless charging system uses a positioning device on the electric vehicle (1) to perform big data analysis on road traffic conditions, thereby providing the best route for drivers and passengers.

9. The electric vehicle wireless charging system based on magnetic coupling resonance according to claim 8, characterized in that: The wireless charging system is combined with the Internet of Vehicles to achieve network connections between different electric vehicles (1) and between the electric vehicle (1) and road pavement (2) facilities, providing the electric vehicle (1) with real-time road condition data and providing full and powerful support for autonomous driving.

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