Intelligent tracking type dynamic wireless electric energy transmission system suitable for high-speed driving electric automobile

Abstract

The invention provides an intelligent tracking type dynamic wireless electric energy transmission system suitable for a high-speed driving electric vehicle. The intelligent tracking type dynamic wireless electric energy transmission system comprises an inverter power supply end, a ground transmitting end, a vehicle-mounted receiving end and a position detection end. The ground transmitting end is composed of a plurality of transmitting units, the transmitting units are connected to the same inverter power supply end through a change-over switch, and each transmitting unit comprises a plurality of transmitting ends connected in parallel. The position detection end is responsible for detecting the running position of the vehicle and controlling the on-off of the switch; and the vehicle-mounted receiving end and the ground transmitting end are both subjected to magnetic shielding and magnetic confinement by adopting a high-permeability magnetic material. The beneficial effects of the invention are that the parallel transmitting terminal realizes automatic following tuning based on the influence of a ferromagnetic material on equivalent electrical parameters and the comprehensive design of the resonant topology, can automatically follow the driving position of the electric vehicle and actively adjust the transmission power distribution of the parallel transmitting terminal; the intelligent tracking dynamic wireless power transmission suitable for the high-speed driving electric automobile is realized.

Description

Technical Field

[0001] The invention belongs to the field of wireless power transmission, and in particular relates to an intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles. Background Art

[0002] Electric vehicles can effectively reduce the consumption rate of fossil energy and improve environmental stability. However, the range anxiety of electric vehicles is an important obstacle to their promotion. Energy batteries are an important part of the cost of electric vehicles. To extend their range, more batteries are needed. The cost of electric vehicles will increase. Reducing the capacity of on-board batteries can reduce the price of vehicles and attract more consumers. However, the range of electric vehicles will be reduced at the same time. How to reduce the cost of electric vehicles while ensuring sufficient range is the key to improving the competitiveness of electric vehicles.

[0003] Wireless power transmission can achieve contactless energy transfer. It removes the restrictions of conductor connection between power supply and load. If the transmitter is infinitely expanded, that is, dynamic wireless power transmission, it can provide power for mobile loads. The power supply characteristics of dynamic wireless power transmission provide a relatively perfect solution for reducing the cost of electric vehicles and improving battery life. In theory, when the power required for electric vehicles to travel is equal to the power provided by dynamic wireless power transmission, electric vehicles can achieve unlimited battery life without batteries. However, dynamic wireless power transmission is currently only applicable to low-speed electric vehicles. When the vehicle speed increases, the control technology requirements such as switching of multiple transmitting units and power distribution are very high. Summary of the invention

[0004] In view of this, the present invention aims to provide an intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles in order to solve at least one of the above-mentioned problems.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] An intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles, characterized by:

[0007] It includes an inverter power supply end, a ground transmitting end, a vehicle-mounted receiving end and a position detecting end.

[0008] Furthermore, the inverter power supply end includes an AC power supply, an inverter circuit and a resonant matching circuit; the ground transmitting end is composed of multiple transmitting units, each transmitting unit includes multiple parallel transmitting ends; the vehicle-mounted receiving end receives the high-frequency AC power emitted by the transmitting end and converts it into electricity for the electric vehicle through a load conversion circuit; the position detection end is used to detect the driving position of the vehicle and control the on and off of the switch.

[0009] Furthermore, the multiple transmitting units are connected to the same inverter power supply terminal through a switching switch; when the car drives to the transmitting unit n-1, the position detection terminal will close the switch of the transmitting unit n-1 and open the switch of the transmitting unit n.

[0010] Furthermore, the transmitting end includes a transmitting coil, a high magnetic permeability material and an acrylic plate; the receiving end structure is the same as the transmitting end; the transmitting coil is a multi-turn Litz coil, and the shape of the coil includes but is not limited to circular, rounded, square, elliptical and other shapes; the high magnetic permeability material is a ferrite material, which is laid on the back side of the coil energy transmission direction for magnetic shielding and magnetic confinement; the transmitting coil adjusts the inductance value in the equivalent connection circuit topology by adjusting the number of turns, radius, turn spacing, and series-parallel connection.

[0011] Furthermore, the spacing between adjacent transmitting ends is the same, including adjacent transmitting ends of different transmitting units.

[0012] Furthermore, when the relative spatial position of the high magnetic permeability material and the coil changes, the equivalent self-inductance and mutual inductance of the coil will also change; there are appropriate transmission distance H and transmitter spacing D, so that when the receiving end moves within the selected section, the impedance modulus value of the corresponding main transmitting end is minimized and the full section range is maximized.

[0013] Furthermore, the parallel transmitting end realizes automatic follow-up tuning based on the influence of ferromagnetic materials on equivalent electrical parameters and the comprehensive design of resonant topology, and can automatically follow the driving position of the electric vehicle to actively adjust the transmission power distribution of the parallel transmitting end.

[0014] Compared with the prior art, the intelligent tracking dynamic wireless power transmission system adapted to high-speed electric vehicles described in the present invention has the following beneficial effects:

[0015] (1) The present invention designs a multi-transmitter parallel type transmitting unit type control (including a branch type LCC compensation topology), and reduces the waste of power resources and the power supply burden of the power supply by controlling the on and off of the switch, which is suitable for wireless power transmission of high-speed electric vehicles;

[0016] (2) The present invention utilizes the influence of high magnetic permeability materials on the equivalent electrical parameters of the coupling mechanism to design the parallel transmitter resonant topology so that multiple parallel transmitters automatically follow the power distribution to achieve intelligent tracking wireless power transmission for high-speed electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 The overall structure function diagram of the embodiment is as follows

[0019] Figure 2 Schematic diagram of the transmitting end structure described in the embodiment

[0020] Figure 3 A simplified diagram of the coupling state between the transmitting end and the receiving end described in the embodiment

[0021] Figure 4 The simplified equivalent circuit of the transmitting unit and the receiving end described in the embodiment

[0022] Figure 5 Schematic diagram of the coupling state of the transmitting end and the receiving end according to the embodiment

[0023] Figure 6 The figure shows the change of the transmitter reactance modulus and its equivalent self-inductance with the receiver position.

[0024] Reference numerals and descriptions: TX1: transmitter 1, TX2: transmitter 2, TX3: transmitter 3, RX1: receiver, L pi : Equivalent self-inductance of the coil at the main transmitting end, C pi : Main transmitter resonant compensation capacitor, R pi : Main transmitter resistance, L pi ′The equivalent self-inductance of the coil at the secondary main transmitting end, C pi ′: sub-transmitter resonant compensation capacitor, R pi ′: secondary emitter resistance, I pi and I pi ′: transmitter current, M pi·s and M pi·s ′: Mutual inductance between the transmitter and the receiver, M pi·s : Mutual inductance between two transmitters, D: Transmitter spacing, H: Height between transmitter and receiver, L RX : Receiver parameters, L TX1 : Transmitter 1 parameters, L TX2 : Transmitter 2 parameters, L TX3 : Transmitter 3 parameters. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0027] An intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles Figure 1As shown, it includes an inverter power supply end, a ground transmitting end, a vehicle-mounted receiving end and a position detection end. The inverter power supply end includes an AC power supply, an inverter circuit and a resonant matching circuit. The ground transmitting end is composed of multiple transmitting units; multiple transmitting units are connected to the same inverter power supply end through a switching switch. Different transmitting units are switched to work according to the position of the vehicle during driving. Each transmitting unit includes multiple parallel transmitting ends; the vehicle-mounted receiving end receives the high-frequency AC power emitted by the transmitting end and converts it into electricity for electric vehicles through a load conversion circuit; the position detection end is used to detect the driving position of the car and control the on and off of the corresponding transmitting unit switch.

[0028] The structure of the transmitter is as follows Figure 2 As shown, it includes a transmitting coil, a high magnetic permeability material and an acrylic plate. The transmitting coil is a multi-turn Litz coil, and the receiving end and the transmitting end have the same structure. The shape of the coil includes but is not limited to circular, rounded, square, elliptical and other shapes; the high magnetic permeability material is ferrite, which is laid on the back side of the coil energy transmission direction, and the magnetic field is more concentrated in the energy transmission direction, while reducing the magnetic field strength on the back side to achieve a shielding effect; the inductance value in the equivalent connection circuit topology is adjusted by adjusting the number of coil turns, radius, turn spacing, and series-parallel connection; when the relative spatial position of the high magnetic permeability material and the coil changes, the equivalent self-inductance and mutual inductance of the coil will also change.

[0029] When in working state, multiple transmitting units switch working state according to the position of the electric vehicle, and only one transmitting unit works at a time. Multiple transmitting ends in parallel transmit energy through coupling with the receiving end. When the receiving end is facing a certain transmitting end, if the number of transmitting ends in the transmitting unit is large enough (or the situation when the receiving end is located at both ends of the transmitting unit is not considered), the coupling state between different transmitting ends and receiving ends is the same. The continuous movement of the receiving end relative to the transmitting unit can be regarded as the continuous repetition of the change process of the coupling state between the multiple transmitting ends and the receiving end. That is, Figure 3 As shown in the figure, when the receiving end moves in the three ranges of [d1, d2], [d2, d3] and [d3, d4], the coupling changes between the transmitting unit and the receiving end are the same. The transmission performance changes of the system are also repeated.

[0030] The equivalent circuits of the transmitting unit and the receiving end in the working state are simplified. The simplified equivalent circuits are as follows: Figure 4 There are only two transmitters, namely the transmitter included in the selected segment range (called the main transmitter) and the equivalent transmitter of all transmitters outside the selected segment range (called the secondary transmitter). pi , C pi and R pi are the equivalent self-inductance, resonant compensation capacitance and resistance of the coil at the main transmitting end, L pi ′、C pi ′ and R pi′ are the equivalent self-inductance, resonant compensation capacitance and resistance of the coil at the secondary transmitting end, I pi and I pi ′ is the transmitting end current, M pi·s and M pi·s ' is the mutual inductance between the transmitter and the receiver, M pi·s is the mutual inductance between the two transmitting ends. Therefore, there is a relatively complex coupling relationship between the transmitting unit and the receiving end.

[0031] The two transmitters are in parallel and have the same port voltage. When the total input power remains unchanged, the transmitter with smaller impedance has a greater share of transmission power. For wireless power transmission, the greater the coupling coefficient, the higher the transmission efficiency. The coupling between the main transmitter and the receiver corresponding to the selected segment range is obviously more advantageous. In order to ensure transmission efficiency and transmission power, it is expected that the main transmitter will receive more power, that is, when the receiver moves within the selected segment range, the impedance of the main transmitter is the smallest.

[0032] The transmission power of multiple parallel transmitters can be automatically distributed according to the position of the receiving end, which is the basis for the proposed solution to adapt to high-speed electric vehicles. Its essence is that the corresponding transmitter in each section is in a resonant state (the main transmitter has the smallest impedance), while the other transmitters are in a non-resonant state.

[0033] The schematic diagram of the coupling relationship between the transmitter and the receiver is as follows: Figure 5 According to the previous analysis, the appropriate transmission distance H and transmitter spacing D are the key to ensure the stability of the equivalent self-inductance corresponding to the segment range, and also the guarantee of the resonance of the corresponding transmitter within a certain segment range.

[0034] When the transmission distance H = 100mm and the spacing D = 150mm, the change of the transmitter reactance modulus value and its equivalent self-inductance is as follows: Figure 6 As shown in the figure, keeping the compensation capacitance and resonant frequency constant, the reactance modulus of the parallel transmitter changes symmetrically with the transmitter reactance modulus value at the receiving end position and its equivalent self-inductance. The corresponding impedance modulus value within the segment range is the smallest, and the value outside the full segment range is very large, which meets the design requirements of the active power distribution of the parallel transmitter mentioned above.

[0035] According to the maximum equivalent self-inductance, all transmitters are resonantly matched. Transmitters that are not within the range of the receiving end must be capacitive. That is, the equivalent reactance of all transmitters at any time must be capacitive. The converter directly provides power to the capacitive coupling mechanism, which poses an overvoltage risk. Zero voltage switching is also impossible. Compensation inductance needs to be added for adjustment. Drawing on the structural mode of the LCC resonant topology, the following is designed: Figure 4 The branch type LCC compensation topology shown. The front end compensation inductor L pp and capacitor C ppThe equivalent capacitance C of all parallel emitters p satisfy

[0036]

[0037] Among them, the equivalent capacitance C of all parallel transmitters p for

[0038]

[0039] Those of ordinary skill in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0040] In the several embodiments provided in the present application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles, characterized by: It includes an inverter power supply end, a ground transmitting end, a vehicle receiving end and a position detecting end; The inverter power supply end includes an AC power supply, an inverter circuit and a resonant compensation topology; The ground transmitting end is composed of a plurality of transmitting units, each transmitting unit comprising a plurality of transmitting ends connected in parallel; The vehicle-mounted receiving terminal includes a receiving terminal and a load conversion circuit; The position detection end is used to detect the driving position of the car and control the on and off of the switch.

2. According to claim 1, the intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles is characterized by: The multiple transmitting units are connected to the same inverter power supply terminal via a switching switch; When the car drives to transmitting unit n-1, the position detection end closes the switch of transmitting unit n-1 and opens the switch of transmitting unit n.

3. According to claim 2, the intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles is characterized by: The transmitting end includes a transmitting coil, a high magnetic permeability material and an acrylic plate, and the receiving end has the same structure as the transmitting end; The transmitting coil is a multi-turn Litz coil, and the shape of the coil includes but is not limited to circular, rounded, square, elliptical and other shapes; The transmitting coil adjusts the inductance value in the equivalent connection circuit topology by adjusting the number of turns, radius, turn spacing, and series-parallel connection; The high magnetic permeability material is ferrite, which is laid on the back side of the coil in the energy transmission direction for magnetic shielding and magnetic confinement.

4. The intelligent tracking dynamic wireless power transmission system for high-speed electric vehicles according to claim 3 is characterized in that: The spacing between adjacent transmitting ends is the same, including adjacent transmitting ends of different transmitting units.

5. According to claim 3, the intelligent tracking dynamic wireless power transmission system suitable for high-speed electric vehicles is characterized by: When the relative spatial position of the high magnetic permeability material and the coil changes, the equivalent self-inductance and mutual inductance of the coil will also change; There are appropriate transmission distance H and transmitter spacing D, so that when the receiving end moves within the selected segment, the impedance modulus of the corresponding main transmitting end is the smallest and the full segment range is the largest.

6. The intelligent tracking dynamic wireless power transmission system for high-speed electric vehicles according to claim 5 is characterized in that: The parallel transmitting end realizes automatic follow-up tuning based on the influence of ferromagnetic materials on equivalent electrical parameters and the comprehensive design of resonant topology, and can automatically follow the driving position of the electric vehicle and actively adjust the transmission power distribution of the parallel transmitting end.

Images