Wireless Charging System

Abstract

The present invention discloses a wireless charging system, which has a transmitting end and a receiving end, wherein the receiving end further includes: a receiving end detection system; the transmitting end detection system includes: a signal generator, a driver, a transmitting circuit and a detection transmitting coil which are connected in sequence; the receiving end detection system includes: a detection receiving coil, a detection circuit and an auxiliary charging circuit, wherein one of the detection circuit and the auxiliary charging circuit is connected to the detection receiving coil; the detection receiving coil is set at least in two positions; the detection transmitting coil is set at least in one position, and when it is in the working range, a mutual inductance is generated between the detection transmitting coil and the detection receiving coil; there are at most three detection receiving coils at one position, and they are oriented in different directions; there are at most three detection transmitting coils at one position, and they are oriented in different directions. On the one hand, it can realize the alignment judgment during wireless charging, and on the other hand, it can supply power to the auxiliary power supply to ensure the normal operation of wireless charging.

Description

Technical Field

[0001] The present invention relates to the field of charging, and in particular to a wireless charging system. Background Art

[0002] As an ideal power supply method for electric vehicles, high-power wireless charging has been rapidly developed and widely used in recent years due to its safety, convenience and high degree of automation. During wireless charging, the transmitting coil and the receiving coil need to be aligned as much as possible to obtain the maximum coupling coefficient and achieve the maximum energy transmission efficiency. Therefore, electric vehicles are generally equipped with an alignment detection system to provide coil alignment guidance for the driver or automatic driving system of the vehicle. The existing alignment technology generally uses the difference between the transmitting power and the receiving power to determine whether it is aligned. This method has large errors and is also greatly affected by the environment. In some solutions, cameras are installed to assist in alignment, but in this method, the working environment of the camera is not easy to guarantee and the cost is high.

[0003] In addition, once the device being charged is completely out of power, such as an electric car, there will be no power to activate the wireless charging function, because at this time the pairing, positioning, and interaction of the transmitting coil and the receiving coil will not work, and ultimately wireless charging will not be able to proceed normally. Summary of the invention

[0004] The present invention provides a wireless charging system, which can provide alignment judgment during wireless charging and has an auxiliary power supply to ensure normal wireless charging.

[0005] The wireless charging system of the present invention has a transmitter and a receiver, wherein the transmitter at least has a transmitter power supply system and a transmitter controller, and the receiver at least has a receiver power supply system and a receiver controller, wherein the transmitter further includes: a transmitter detection system; the receiver further includes: a receiver detection system; the transmitter detection system includes: a signal generator, a driver, a transmitter circuit and a detection transmitter coil connected in sequence; the receiver detection system includes: a detection receiver coil, a detection circuit and an auxiliary charging circuit, wherein one of the detection circuit and the auxiliary charging circuit is connected to the detection receiver coil, and the auxiliary charging circuit includes an auxiliary power supply, which is connected to the receiver controller; the detection receiver coil is arranged at least in two positions, respectively located on both sides of the receiver power supply system; the detection transmitter coil is arranged at least in one position, and when in the working range, mutual inductance is generated between the detection transmitter coil and the detection receiver coil; the detection receiver coils at one position have at most three and are in different directions; the detection transmitter coils at one position have at most three and are in different directions; the working frequency of the detection transmitter coil is different from the working frequency of the transmitter power supply system.

[0006] Preferably, the transmitting circuit has at least one transmitting loop; in each transmitting loop, one detecting transmitting coil is connected; each transmitting loop also includes: a transmitting loop switch and a transmitting loop capacitor connected in series with the detecting transmitting coil.

[0007] Preferably, the X dimension, Y dimension and Z dimension are defined based on a three-dimensional rectangular coordinate system; two transmitting circuits or three transmitting circuits are taken as a group, and the orientations of the detection transmitting coils in the same group are not repeated in the X dimension, Y dimension and Z dimension.

[0008] Preferably, the detection circuit has at least one receiving circuit, and each receiving circuit is connected to one of the detection receiving coils; each receiving circuit also includes: a receiving circuit switch and a receiving circuit capacitor connected in series with the detection receiving coil.

[0009] Preferably, the X dimension, Y dimension and Z dimension are defined based on a three-dimensional rectangular coordinate system; two receiving loops or three receiving loops are used as a group, and the orientations of the detection receiving coils in the same group are not repeated in the X dimension, Y dimension and Z dimension.

[0010] Preferably, the auxiliary charging circuit includes: a working resonant network, a working rectifier, a working filter and an auxiliary power supply connected in sequence; the working resonant network is connected to or disconnected from the detection receiving coil via an auxiliary charging switch.

[0011] Preferably, the auxiliary charging circuit includes: a working resonant network, a working rectifier, a working filter and an auxiliary power supply connected in sequence; the working resonant network is connected or disconnected with the detection receiving coil through an auxiliary charging switch; the receiving circuit switch and the auxiliary charging switch are the same switch, and the above-mentioned detection receiving coil is selectively connected to the detection circuit or to the auxiliary charging circuit.

[0012] Preferably, the transmitter also includes: a transmitter controller and a transmitter communication system; the transmitter controller is respectively connected to the transmitter power supply system and the transmitter communication system.

[0013] Preferably, the receiving end also includes: a receiving end controller and a receiving end communication system; the receiving end controller is respectively connected to the receiving end power supply system, the detection circuit, the auxiliary charging circuit, and the receiving end communication system; the receiving end communication system is also connected to the auxiliary charging circuit.

[0014] In the wireless charging system of the present invention, the receiving end detection system has a detection circuit and an auxiliary charging circuit, which can realize alignment judgment during wireless charging on the one hand, and supply power to the auxiliary power supply on the other hand to ensure the normal operation of wireless charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural block diagram of the wireless charging system of the present invention;

[0016] Figure 2 It is a partial schematic diagram of the detection circuit and the auxiliary charging circuit in the wireless charging system of the present invention;

[0017] Figure 3 A schematic diagram of a transmitting circuit and a receiving circuit in a wireless charging system of the present invention;

[0018] Figure 4 A schematic diagram of the composite coil structure in the wireless charging system of the present invention;

[0019] Figure 5 A schematic diagram of the parking area.

[0020] Reference numerals:

[0021] Transmitting end T; receiving end R; transmitting loop switch TK; transmitting loop capacitor TC; transmitting loop inductor TL; transmitting loop resistor TR; receiving loop switch RK; receiving loop capacitor RC; receiving loop inductor RL; receiving loop resistor RR; auxiliary switch WK; switch K;

[0022] Parking area 0; transmitter detection system 1; transmitter power supply system 2; transmitter controller 3; transmitter communication system 4; receiver detection system 5; receiver power supply system 6; receiver controller 7; receiver communication system 8; signal generator 11; driver 12; transmitter circuit 13; detection transmitter coil 14; power supply 21; transmitter DC converter 22; transmitter inverter 23; transmitter resonant network 24; power transmitter coil 15; detection receiver coil 51; working resonant network 52; working rectifier 53; working filter 54; auxiliary power supply 55; detection circuit 56; load 61; receiver filter 62; receiver rectifier 63; receiver resonant network 64; power receiver coil 65. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0024] The present invention discloses a wireless charging system, such as Figure 1As shown, the wireless charging system is divided into a transmitting end T and a receiving end R. For the convenience of explanation, the following description will be made by taking an electric car as an example. At this time, the transmitting end T is the ground end, which is used to provide wireless power output, and the receiving end R is the vehicle end, which is used to receive wireless power. It should be noted that the wireless charging of electric vehicles is only an example of this application and is not intended to limit the scope of use of this application.

[0025] The transmitting end T has a transmitting end detection system 1, a transmitting end power supply system 2, a transmitting end controller 3 and a transmitting end communication system 4. The receiving end R has a receiving end detection system 5, a receiving end power supply system 6, a receiving end controller 7 and a receiving end communication system 8.

[0026] The transmitting end power supply system 2 is used for power supply, including a power supply 21, a transmitting end DC converter 22, a transmitting end inverter 23, a transmitting end resonant network 24 and a power transmitting coil 15. The receiving end power supply system 6 is used to cooperate with the transmitting end power supply system 2 to obtain electrical energy. The receiving end power supply system 6 includes a load 61, a receiving end filter 62, a receiving end rectifier 63, a receiving end resonant network 64 and a power receiving coil 65. For the convenience of explanation, the transmitting end power supply system 2 and the receiving end power supply system 6 can be collectively referred to as a power module.

[0027] The transmitting end detection system 1 is used to detect whether the transmitting end T and the receiving end R are aligned during wireless charging (also called positioning detection). The receiving end detection system 5 cooperates with the above-mentioned transmitting end detection system 1 to detect whether the transmitting end T and the receiving end R are aligned during wireless charging. At the same time, the transmitting end detection system 1 and the receiving end detection system 5 respectively have coils - a detection transmitting coil 14 and a detection receiving coil 51. The two coils can also transmit electrical energy to charge the auxiliary power supply 55 (see the detailed description below for details). Because it can realize the two functions of alignment detection and auxiliary charging (different from the charging of the power module, here it only means charging the auxiliary power supply 55), for the convenience of explanation below, the transmitting end detection system 1 and the receiving end detection system 5 are collectively referred to as dual-use modules.

[0028] The transmitter controller 3 exchanges information with the transmitter communication system 4, adjusts the working state of the transmitter power supply system 2 according to the information received by the transmitter communication system 4, and can also share the working state information of the transmitter power supply system 2 with the transmitter communication system 4, and the transmitter communication system 4 sends the corresponding information to other receivers (such as the receiving communication system 8 of the receiving end R). The receiving controller 7 is connected to the receiving communication system 8, the receiving detection system 5, and the receiving power supply system 6 respectively for control. The receiving communication system 8 and the transmitter communication system 4 communicate signals and exchange information. The receiving communication system 8 also sends the exchanged information to the receiving controller 7. It can be seen that the transmitter communication system 4 and the receiving communication system 8 realize the information exchange and sharing between the transmitter T and the receiver R.

[0029] Taking an electric vehicle as an example, the working mode of the power module is explained. The receiving end R is installed on the electric vehicle. When the power receiving coil 65 is aligned with the power transmitting coil 15 (or the offset between the two coils meets the working range), under the control of the transmitting end controller 3, the AC power output by the power supply 21 is converted into DC power by the transmitting end DC converter 22. The transmitting end DC converter 22 may include a filter circuit, a rectifier circuit and a power factor adjustment circuit. Then the DC power is converted into high-frequency AC power by the transmitting end inverter 23 and applied to the transmitting end resonant network 24. The power transmitting coil 15 excites the upper space to form a high-frequency alternating magnetic field. The power receiving coil 65 generates AC current through magnetic field coupling, and then converted into DC power after passing through the receiving end rectifier 63 and the receiving end filter 62. The output DC power is input to the load 61 (generally a vehicle-mounted power battery) for charging.

[0030] During the entire charging process, the transmitter T and the receiver R exchange information through their respective communication systems (transmitter communication system 4 and receiver communication system 8), and the communication modes between the communication modules include WIFI, radio frequency communication, Zigbee, Bluetooth, millimeter wave, optical communication, etc. The controllers at both ends collect control signals such as current and voltage at their respective ends through sensors. The transmitter controller 3 adjusts the output of the transmitter DC converter 22 and the transmitter inverter 23 according to the charging demand, thereby transmitting the required output power.

[0031] The transmitting end detection system 1 and the receiving end detection system 5 are described below.

[0032] The transmitting end detection system 1 includes: a signal generator 11, a driver 12, a transmitting circuit 13 and a detection transmitting coil 14 which are connected in sequence; the receiving end detection system 5 includes: a detection receiving coil 51, a detection circuit 56 and an auxiliary charging circuit, and one of the detection circuit 56 and the auxiliary charging circuit is connected to the detection receiving coil 51. Figure 1 As shown, the switch K is used to realize the selection of the two circuits for detecting the receiving coil 51. The use of the switch K here is only an optional method, which will be described in detail below.

[0033] When the detection receiving coil 51 and the detection circuit 56 are connected, it is used to detect whether the transmitting end T and the receiving end R are aligned, or whether they are within the working range. When they are within the working range, mutual inductance is generated between the detection transmitting coil 14 and the detection receiving coil 51, and the mutual inductance coefficient of the mutual inductance is M. After processing by the detection circuit 56, the positioning judgment is realized.

[0034] When the detection receiving coil 51 is connected to the auxiliary charging circuit, mutual inductance is generated between the detection transmitting coil 14 and the detection receiving coil 51 (of course, it is also within the working range), which is similar to the power module, realizing wireless power transmission. However, the power transmission in the dual-use module is to power the auxiliary power supply 55. Taking the car as an example, the auxiliary power supply 55 can be a vehicle-mounted level. When the battery of the electric car is completely out of power, it may be impossible to charge (for example, the receiving end controller 7 cannot be started and charging cannot be achieved). At this time, the auxiliary power supply 55 can supply power to ensure the start of wireless charging. Of course, the auxiliary power supply 55 can also be connected to other devices that need power supply, such as the receiving end communication system 8, or the auxiliary charging switch WK, receiving circuit switch RK and other components that need to be electrically driven as mentioned below.

[0035] The following describes the detection function of the dual-use module and the "auxiliary charging" function. These two functions are switched by switches, and there are many different ways to set the switch in different implementations. In the following description of the detection of the transmitting coil 14 and the detection of the receiving coil 51, no matter which function is universal, because they all use the same detection receiving coil 51, but are connected to different circuits.

[0036] Both the detection transmitting coil 14 and the detection receiving coil 51 can have multiple ones, facing different dimensions, to ensure that more detection data is obtained. In some embodiments, at least two detection receiving coils 51 are set, respectively located on both sides of the receiving end power system 6, generally on both sides of the power receiving coil 65. The detection transmitting coil 14 is set at least in one position, which can be guaranteed to work (it can generate mutual inductance with the detection receiving coil 51 within the working range), generally near the power transmitting coil 15, and can also be shared with the power transmitting coil 15, that is, the power transmitting coil 15 can be used as the detection transmitting coil 14. Whether it is a detection transmitting coil 14 or a detection receiving coil 51, at most three can be set in one position, and the three directions are different, generally three directions perpendicular to each other. Please refer to the following description for details.

[0037] The transmitting circuit 13 has at least one transmitting circuit; in each transmitting circuit, a detection transmitting coil 14 is connected; each transmitting circuit also includes: a transmitting circuit switch TK and a transmitting circuit capacitor TC connected in series with the detection transmitting coil 14. In other words, the transmitting circuit 13 may have multiple transmitting circuits, each transmitting circuit corresponds to a detection transmitting coil 14, and the switching between working and stopping is realized by the transmitting circuit switch TK. Generally, when there are multiple detection transmitting coils 14, each detection transmitting coil 14 can work in sequence, and generally do not work at the same time.

[0038] The X dimension, Y dimension and Z dimension (hereinafter referred to as "dimension") are defined based on a three-dimensional rectangular coordinate system; two transmitting loops or three transmitting loops are used as a group, and the orientation of the detection transmitting coil 14 in the same group is not repeated in the X dimension, Y dimension and Z dimension. Taking an electric car as an example, the X dimension is generally the direction of the vehicle's travel, and the Y dimension is the left and right direction of the vehicle, which is perpendicular to the X dimension. The Z dimension is perpendicular to the other two dimensions and generally refers to the direction perpendicular to the vehicle chassis.

[0039] When there are three transmitting loops as a group, the three detecting transmitting coils 14 are respectively in the X dimension, Y dimension and Z dimension, that is, there is a corresponding detecting transmitting coil 14 in each dimension. When there are two transmitting loops as a group, generally in the X dimension and Y dimension, because the Z dimension is generally the distance between the ground end and the vehicle end, that is, the distance between the transmitting end T and the receiving end R in the vertical direction. Near the working range, the difference in this distance is generally not too large, because the height of the vehicle chassis is relatively fixed, even if the vehicle is of different types, there will not be a huge difference in the height of the chassis.

[0040] Correspondingly, in the receiving end detection system 5, the detection circuit 56 has at least one receiving circuit, each receiving circuit is connected to a detection receiving coil 51; each receiving circuit also includes: a receiving circuit switch RK and a receiving circuit capacitor RC connected in series with the detection receiving coil 51. It should be noted that at the receiving end R, the detection receiving coil 51 will be connected to either the detection circuit 56 or the auxiliary charging circuit, and the receiving circuit switch RK will be connected when the detection receiving coil 51 needs to be connected to the detection circuit 56. Of course, in different embodiments, the receiving circuit switch RK may be set in different ways.

[0041] With two receiving loops or three receiving loops as a group, the directions of the detection receiving coils 51 in the same group are not repeated in the X dimension, Y dimension and Z dimension. This is similar to the arrangement of the detection transmitting coil 14, so it is not repeated here.

[0042] In order to ensure that there is no mutual influence with the power transmission, the working frequency of the detection transmitting coil 14 is different from the working frequency of the transmitting end power supply system 2, that is, different from the working frequency of the power transmitting coil 15. Even when the detection transmitting coil 14 and the power transmitting coil 15 are shared, the two functions are performed separately and work at different powers.

[0043] The auxiliary charging circuit is described below. The auxiliary charging circuit includes the following connected in sequence: a working resonant network 52, a working rectifier 53, and a working filter 54. The working resonant network 52 is connected or disconnected with the detection receiving coil 51 through the auxiliary charging switch WK.

[0044] The settings of the receiving loop switch RK and the auxiliary switch WK can be as follows: Figure 2 As shown, the general auxiliary charging switch WK is a normally closed switch, and the receiving circuit switch RK is a normally open switch. Only when alignment judgment is required, the open and closed states are switched, the receiving circuit switch RK is closed, and the auxiliary charging switch WK is opened, so that the detection circuit 56 works. At other times, the auxiliary charging circuit works to ensure the power of the auxiliary power supply 55.

[0045] In some embodiments, the receiving circuit switch RK and the auxiliary charging switch WK are the same switch, and the detection receiving coil 51 is selectively connected to the detection circuit 56 or to the auxiliary charging circuit. Regardless of the switch setting method, as long as the detection receiving coil 51 can be connected to two different circuits, it can be used in this application.

[0046] The auxiliary power supply 55 can supply power to the low-voltage equipment of the receiving end R, which is generally a car battery. The power of the car battery is generally managed and replenished by the vehicle controller and the battery management system (BMS). In some usage scenarios, the car battery of an electric vehicle cannot be used, such as when the car is idle in a parking space for a long time, the car battery is exhausted due to long-term standby, or because the car battery is damaged.

[0047] Since the receiving end control system 7 and the receiving end communication system 8 need to be started when wireless charging is started, the wireless charging cannot be started if the above situation occurs.

[0048] The auxiliary charging circuit in the dual-use module can solve the above problems.

[0049] The signal generator 11 generates a (sinusoidal) signal, and sends the signal to the driver 12 for processing (processing includes power amplification, etc.). The processed signal drives one or more transmitting circuits to work. The corresponding detection transmitting coil 14 in the transmitting circuit excites the space in the corresponding dimension to form a high-frequency alternating magnetic field. One or more detection receiving coils 51 generate an alternating current through magnetic field coupling, which is then converted into direct current after passing through a working rectifier 53 and a working filter 54. The output direct current is input to an auxiliary power supply 55 to power the auxiliary power supply. If the auxiliary power supply is a vehicle-mounted battery, it is to charge the battery. When the battery has a certain amount of power, the normal wireless charging process is started. The filter can also be directly electrically connected to the low-voltage device to directly power the voltage device. Since the operating frequency of the signal generator is different from the operating frequency of the wireless charging, the alternating magnetic fields emitted by the two systems will not interfere with each other even if they are in the same transmission space.

[0050] In some embodiments, the auxiliary power supply 55 may not be used. After the coil alignment detection process is completed, during the startup of the wireless charging system and the entire charging process, the low-voltage components such as the vehicle controller are powered by the detection of the transmitting coil 14 and the detection of the receiving coil 51. The principle is similar to the charging of the auxiliary power supply 55 mentioned above. At this time, the use of the auxiliary power supply 55 can be cancelled, or the auxiliary power supply 55 is not charged, but the power is directly supplied to the electrical components.

[0051] When the detection transmitting circuit works in the auxiliary power supply mode, the power transmitting coil and the receiving coil are in an aligned state and can transmit energy at high power. The alternating magnetic field emitted by the energy transmission system is mainly concentrated in the working area at the bottom of the vehicle. At this time, the emitted magnetic field strength can be higher than the strength during the coil alignment detection, in order to meet the power transmission needs of the auxiliary power supply. However, the magnetic field strength leaked to the charging protection area outside the vehicle is still subject to the magnetic field strength value allowed by national regulations.

[0052] See also Figure 3 Since both the transmitting circuit and the receiving circuit can have multiple switches, "RK1, RK2...RKn" represent different receiving circuit switches RK, and similarly "WK1, WK2...WKn" represent different auxiliary switches WK. "TK1, TK2...TKn" are transmitting circuit switches TK.

[0053] In general, multiple transmission circuit switches TK will not be closed at the same time, but closed in sequence. However, the receiving end detection system 5 is different, which can synchronize the opening and closing states of multiple switches, that is, multiple receiving circuit switches RK such as "RK1, RK2...RKn" are linked, and multiple auxiliary switches WK such as "WK1, WK2...WKn" are also linked, and they are "closed or opened at the same time". It is also possible to set only one linked switch to close and open multiple receiving circuits at the same time.

[0054] As mentioned above, the detection transmitting coil 14 and the detection receiving coil 51 can be arranged in multiple dimensions, so there may be a situation where the three detection transmitting coils 14 are located at the same position, that is, three detection transmitting coils 14 are arranged at one position, corresponding to three dimensional directions respectively. Similarly, there is also a situation where one position includes three detection receiving coils 51. Figure 4 As shown, a composite coil structure is shown, which has detection and transmitting coils 14 in three dimensions at the same time.

[0055] In one embodiment, the detection transmitting coil 14 in the Z dimension generally adopts an independent winding. In another embodiment, the detection transmitting coil 14 in the Z dimension can also be shared with the power transmitting coil 15, that is, the power transmitting coil 15 generates a detection electromagnetic field during the positioning detection process, and at this time, the detection transmitting coils 14 in other dimensions can be wound on the power transmitting coil 15.

[0056] When applied to electric vehicles, the detection transmitting coil 14 and the detection receiving coil 51 can be set at one position or multiple positions. For example, in one embodiment, the detection transmitting coil 14 is set at one position, and the detection receiving coil 51 is set at two positions. In this case, it is generally near the power transmitting coil 15. One position can have one to three dimensional directions. When only one dimensional direction is set at one position, it is generally the Z dimension direction; the detection receiving coil 51 is on both sides of the power receiving coil 65. In a preferred embodiment, the detection receiving coil 51 can be symmetrically set at four positions on the periphery of the power receiving coil 65.

[0057] Taking electric vehicles as an example, the workflow and method are described. It should be noted that the electric vehicle is used as an example for the convenience of description and understanding, and does not limit the solution of the present application to only electric vehicles.

[0058] When an electric car that needs to be charged approaches or enters a wireless charging area (such as a parking lot that can be wirelessly charged), the transmitting end communication system 4 and the receiving end communication system 8 establish communication, and the transmitting end T and the receiving end R exchange the required information and data through communication.

[0059] When the alignment detection of the power transmitting coil 15 and the power receiving coil 65 is to be performed, the control receiving circuit switch RK is closed and the auxiliary charging switch WK is opened (which can be controlled by the receiving end controller 7). The signal generator 11 generates a (sinusoidal) signal and sends the signal to the driver 12 for processing (processing includes power amplification, etc.). The processed signal drives a transmitting circuit to work, and the corresponding detection transmitting coil 14 in the transmitting circuit emits the detection electromagnetic field required for alignment to the spatial excitation in the corresponding dimensional direction (the same as the high-frequency alternating magnetic field mentioned when explaining the auxiliary charging circuit above. These two places are distinguished in name to distinguish different functions, that is, the "electromagnetic field" emitted by the transmitting coil 14 can be used for positioning detection and for charging the auxiliary power supply 55). The intensity of the detected electromagnetic field is subject to the magnetic field intensity value allowed to be exposed in the public environment by the national regulations during wireless charging. The frequency of the detected electromagnetic field can be different from the frequency of the magnetic field generated by the power transmission of the charging module. That is, the detection electromagnetic field and the electromagnetic field generated during wireless charging have different frequencies.

[0060] The detection transmitting coil 14 emits a detection electromagnetic field according to a fixed period. When the detection transmitting coil 14 does not emit the detection electromagnetic field, the detection receiving coil 51 receives the environmental electromagnetic field (which belongs to the interference magnetic field). When the detection transmitting coil 14 emits the detection electromagnetic field, the receiving detection coil 51 receives the superposition of the environmental electromagnetic field and the transmitting electromagnetic field. The data detected during the working period of the detection transmitting coil 14 is subtracted from the data detected during the non-working period, and the actual transmission value of the transmitting coil 14 can be obtained.

[0061] When the transmitting loop is greater than 1 (there are multiple transmitting coils 14), in order to avoid mutual interference, only one transmitting loop works at the same time in each working cycle. In some embodiments, the transmitting coils 14 in three dimensions are set at the same position. Even so, only one transmitting coil 14 in one dimension works, and generally, the transmitting coils 14 in different dimensions at the same position work in sequence. If detection transmitting coils 14 are set at multiple positions, it is necessary to complete one position before the detection transmitting coil 14 at another position works in sequence. To avoid interference, only one detection transmitting coil 14 in one dimension at one position works at a time, that is, at the same time, only one transmitting coil 14 works as the emission source of the detection electromagnetic field.

[0062] It should be noted that when one of the transmitting coils 14 is working, it may include one or more working cycles, that is, each detection transmitting coil 14 may work for one cycle or multiple cycles in turn.

[0063] During the entire alignment detection process, all the switches RK of the receiving circuit are turned on (RK1 to RKn are all turned on). At this time, all the receiving circuits work simultaneously, and the measured data are sent to the receiving end controller 7 at the same time.

[0064] When the electric vehicle gradually approaches the power transmitting coil, the strength of the detection electromagnetic field signal emitted by the detection transmitting coil 14 received by the detection receiving coil 51 gradually increases, and the magnetic field strength received by each receiving circuit (detection receiving coil 51) is sufficient to measure the voltage U1 to Un through the detection circuit 56.

[0065] See also Figure 3 In a receiving loop, when the receiving coil 51 is connected, the receiving loop has a receiving loop inductance RL, a receiving loop resistance RR and a receiving loop capacitance RC (when there are multiple receiving loops, they are represented by RL1 to RLn, RR1 to RRn, RC1 to RCn respectively). In the transmitting loop, there is a transmitting loop inductance TL, a transmitting loop resistance TR and a transmitting loop capacitance TC (when there are multiple transmitting loops, they are represented by TL1 to TLn, TR1 to TRn, TC1 to TCn respectively).

[0066] The transmitting loop capacitance TC, transmitting loop inductance TL, transmitting loop resistance TR, receiving loop capacitance RC, receiving loop inductance RL, and receiving loop resistance RR mentioned above generally refer to equivalent values ​​in the receiving loop. For example, the resistance provided by the receiving coil 51 and the wires in the circuit is detected as the receiving loop resistance RR.

[0067] The receiving circuit and the transmitting circuit are both in a "LC series-series" resonant topology. The mutual inductance coefficient M for realizing mutual inductance between the detection transmitting coil 14 and the detection receiving coil 51 is:

[0068]

[0069] Where U is the measured voltage of the receiving circuit; I is the AC voltage U loaded by the driver 12 when the transmitting coil 14 is unloaded. 0 The current generated in the transmitting loop after the oscillation frequency is a known value. I can be a fixed value predetermined by the system or a value measured before positioning. f is the oscillation frequency of the AC signal sent by the signal generator 11, which is also a known value. I and f can be transmitted between the receiving end communication system 8 and the transmitting end communication system 4.

[0070] When there are multiple detection receiving coils 51, there are multiple receiving circuits, so each receiving circuit has a corresponding measurement voltage, and the measurement voltage of each receiving circuit is represented by U1 to Un. Similarly, the current of each transmitting circuit under the above-mentioned limited conditions is represented by I1 to In.

[0071] In operation, a detection transmitting coil 14 and each detection receiving coil 51 have mutual inductance, and their mutual inductance coefficients are also different. For the sake of clarity, the above mutual inductance coefficient M can also be expressed as

[0072]

[0073] That is, the mutual inductance coefficient between the Xth detection transmitting coil 14 and the Yth detection receiving coil 51. Through the above, the mutual inductance coefficient between each detection transmitting coil 14 and each detection receiving coil 51 can be known.

[0074] It should be noted that the above formula for the mutual inductance coefficient M is calculated based on the data on both sides when the mutual inductance occurs between the detection transmitting coil 14 and the detection receiving coil 51, which can be understood as "real-time data". It should be noted that the above formula for calculating the mutual inductance coefficient M is a preferred embodiment and does not limit other ways to obtain the mutual inductance coefficient M, such as using a measuring instrument to directly measure in real time.

[0075] The following text may also involve the calculation of the theoretical mutual inductance coefficient M'. The theoretical mutual inductance coefficient M' is obtained by artificial calculation based on a mathematical model. Even if there is no mutual inductance between the coils, the theoretical mutual inductance coefficient M' can be obtained. Corresponding to the above-mentioned "real-time data", the theoretical mutual inductance coefficient M' can be used as the basis for verification. By comparing with the "real-time data", it can be determined whether the coils are aligned. For details, please refer to the following text, which will explain the method of positioning detection.

[0076]

[0077] in:

[0078]

[0079] The meanings of the letters in the above formula are as follows:

[0080] μ 0 : vacuum permeability;

[0081] r 1 : Detect the radius of the transmitting coil 14;

[0082] r 2 : Detect the radius of the receiving coil 51;

[0083] n 1 : Detect the number of winding turns of the transmitting coil 14;

[0084] n 2 : Detect the number of winding turns of the receiving coil 51;

[0085] l: the distance between the center points of the detection transmitting coil 14 and the detection receiving coil 51 in a plane, where the plane is the plane where the X dimension and the Y dimension are located;

[0086] h: the offset distance between the detection transmitting coil 14 and the detection receiving coil 51 in the Z dimension direction.

[0087] The above method can obtain the theoretical mutual inductance between each detection transmitting coil 14 and each detection receiving coil 51. XY That is, it can represent the theoretical mutual inductance coefficient between the Xth detection transmitting coil 14 and the Yth detection receiving coil 51 .

[0088] We can know from l and h in the formula that M' can be known at any position between the detection transmitting coil 14 and the detection receiving coil 51 (the mutual inductance is 0 at the position where the detection electromagnetic field cannot be received).

[0089] The theoretical mutual inductance coefficient M' can be used to compare with the above mutual inductance coefficient M to assist in determining the position. See below for details.

[0090] In other embodiments, the theoretical mutual inductance coefficient M' is obtained by calibrating the feature library in advance, that is, at each position where the detection transmitting coil 14 is provided, the mutual inductance coefficient M between the detection receiving coil 51 and the detection transmitting coil 14 in three dimensions is actually measured by the above-mentioned calculation method, thereby establishing a feature library of the mutual inductance system number M of all positions, and using the data of the feature library as the theoretical mutual inductance coefficient M' (it can be understood as performing an actual measurement, and using the result of the actual measurement as the theoretical mutual inductance coefficient M', and the result of the one measurement can be used multiple times).

[0091] The above two methods of obtaining the theoretical mutual inductance coefficient M' can also be used in combination, that is, actual measurements are carried out on site to obtain data to verify the accuracy of Formula 3 and Formula 4, and through computer simulation and interference factor analysis, feasible mathematical methods are obtained to change parameter values ​​or even functional relationships, and correct Formula 3 and Formula 4 so that the calculated value of the formula and the error value calibrated on site are within the required accuracy. The on-site measurement method can also verify Formula 1 and Formula 2.

[0092] Since the operating frequency of the signal generator 11 is different from the frequency of the transmitting end power supply system, the dual-use module can also be used as a no-load protection mechanism for the power transmitting coil 15. During the wireless charging process, it is verified that the relative position between the power transmitting coil 15 and the power receiving coil 65 has not changed. When the vehicle is moved from the charging position, such as being knocked away or the vehicle slipping due to the slope of the parking space, etc., the dual-use module is used for positioning detection. Once the vehicle is found to have deviated from the working range, the power transmission of the transmitting end power supply system 2 can be immediately cut off, and an alarm is issued to the system background. Of course, this requires the cooperation of multiple components such as the transmitting end controller 3, the transmitting end communication system 4, the receiving end controller 7 and the receiving end communication system 8. In this case of use, the aforementioned method of using the detection transmitting coil 14 and the detection receiving coil 51 to power low-voltage components such as the vehicle-mounted controller during the wireless charging process cannot be adopted (the auxiliary power supply 55 cannot be charged).

[0093] The following uses an electric car as an example to illustrate the positioning detection method of the wireless charging system of the present application.

[0094] A parking area is defined, and the transmitter T is installed in the parking area. Based on the wireless charging car, the receiver R is generally installed in the middle and rear position of the vehicle chassis, and the transmitter T is also preferably set in the center and rear of the parking area.

[0095] like Figure 5As shown, the charging area 0 is virtually gridded, and then a feature library of the theoretical mutual inductance coefficient M' is established. The grid division and the establishment of the feature library are called pre-steps. The establishment of this feature library can not only be obtained through theoretical calculations, but also by actually parking the vehicle at various locations for data collection, or by separately disassembling the detection receiving coil 51 and the corresponding detection circuit 56 originally installed on the vehicle receiving end R, and placing them in the corresponding grid for data collection. The pre-step can be simply understood as establishing a foundation, forming corresponding data access, and using it in the subsequent positioning steps.

[0096] The above grid is for the convenience of positioning, and can clearly detect the location of the receiving coil 51. The use of coordinates can play the same function.

[0097] Let's take the example of actually parking the vehicle at various locations to obtain the theoretical mutual inductance coefficient M'. For example, in a 10X10 grid, when a detection receiving coil 51 is in the first row and first column of the grid, the mutual inductance coefficient M between it and all the detection transmitting coils 14 can be used as part of a feature library, and each grid is used as a part to constitute the entire feature library. The mutual inductance coefficient M at this time will be used as the theoretical mutual inductance coefficient M', that is, the actual measurement result in the previous step is used as the theoretical mutual inductance coefficient M'. In the embodiment where the vehicle is not actually parked at various locations, the theoretical mutual inductance coefficient M' can be directly obtained by calculation.

[0098] In actual measurement, the calculation method of the mutual inductance coefficient M can refer to the above formula 1 and formula 2.

[0099] The method of directly calculating the theoretical mutual inductance coefficient M' can refer to the above formula 3 and formula 4.

[0100] It should also be noted that the detection receiving coils 51 may be set at multiple locations on the vehicle, and the data in the grid corresponding to the detection receiving coils 51 at each location will be stored in the feature library.

[0101] At the same time, the detection receiving coil 51 at a position may also have three dimensional directions, so each grid may contain a large number of mutual inductance coefficients M. Even if it is obtained by calculation, each theoretical mutual inductance coefficient M' will be calculated according to the number of coils and the number of dimensional directions, thereby forming a complete feature library.

[0102] Similarly, because the detection transmitting coil 14 can also have multiple positions and multiple dimensional directions, but the position and dimensional direction of the detection transmitting coil 14 are fixed. In simple terms, when each detection receiving coil 51 is in each grid area, all the mutual inductance coefficients M between it and all the detection transmitting coils 14 are made into a set, and this set is the feature library. When using the calculation method, the theoretical mutual inductance coefficients M' of all coils corresponding to each grid are also calculated.

[0103] The feature library of the theoretical mutual inductance coefficient M' can be obtained by actually measuring each mutual inductance coefficient M and then sorting the set, or can be obtained by theoretical calculation using the above formula 3 and formula 4.

[0104] In the embodiment obtained by calculation, because the acquisition of the theoretical mutual inductance coefficient M' includes two data of l and h (see above), these two data can determine the position of the electric vehicle, therefore, the theoretical mutual inductance coefficient M' can have: the data when the vehicle meets the charging position requirements. That is, when the parking position of the vehicle ensures that the power transmitting coil and the power receiving coil are aligned, the theoretical mutual inductance coefficient M' between any detection transmitting coil 14 and each detection receiving coil 51. For the convenience of description, we refer to the theoretical mutual inductance coefficient M' when the vehicle is parked accurately as the determined theoretical mutual inductance coefficient M'. When the vehicle is actually parked at various positions for measurement, the mutual inductance coefficient M obtained when the parking is accurate is referred to as the determined theoretical mutual inductance coefficient M'.

[0105] There are multiple ways to perform positioning detection, and two of them are used as examples below. Corresponding to the above-mentioned pre-steps, the following two methods are called positioning steps.

[0106] The first one:

[0107] A set of mutual inductance coefficients M is obtained. At this time, a vehicle actually needs to be wirelessly charged, and is parked in the charging area 0. Here, "a set" refers to the mutual inductance coefficients of the detection receiving coil 51 and all the detection transmitting coils 14 in all dimensional directions at one position based on the detection receiving coil 51.

[0108] The mutual inductance coefficient M is compared with the feature library. When the comparison results are the same or within the allowable error range, the grid corresponding to the theoretical mutual inductance coefficient M' is mapped through the feature library as the basic grid. The basic grid is the position of the current detection receiving coil 51, or the position of the detection receiving coil 51 can be determined through the basic grid.

[0109] Assume that detection receiving coils 51 are respectively arranged at the four corners of the power receiving coil 65, and the detection receiving coil 51 at each position has three directions (for example Figure 4At the same time, the detection transmitting coil 14 set on the ground, and the detection receiving coil 51 at each position have three directions, but there will be more ground setting positions. For the convenience of explanation, we assume that the detection receiving coil 51 is set at two positions in the ground power transmitting coil 15, and each position has three directions.

[0110] At this time, a set of mutual inductance coefficients M should have 18, namely M 11 、M 21 、M 31 、M 41 、M 51 、M 61 、M 12 、M 22 、M 32 、M 42 、M 52 、M 62 、M 13 、M 23 、M 33 、M 43 、M 53 、M 63 , where the first subscript 1-3 represents the three-dimensional orientation of the detection receiving coil 51 at one position, 4-6 represents the three-dimensional orientation of the detection transmitting coil 14 at the second position, and the second subscript 1-3 represents the three-dimensional orientation of the detection receiving coil 51 at one position. For example, M 63 Represents the mutual inductance M between the detection transmitting coil 14 in the third dimension orientation at the second position and the detection receiving coil 51 in the third dimension orientation at the first position.

[0111] Then, the mutual inductance coefficients M of other positions are measured according to the number of positions where the receiving coil 51 is installed. According to the above example, one position has 18 mutual inductance coefficients M, which can be four groups in total, with a total of 72 mutual inductance coefficients M.

[0112] When these mutual inductance coefficients M are the same as or within the allowable error range of a corresponding set of theoretical mutual inductance coefficients M' in the determined theoretical mutual inductance coefficients M', it is considered that the parking position of the vehicle is accurate. Each detection transmitting coil 14 and detection receiving coil 51 has its own number, so it is convenient to find a set of theoretical mutual inductance coefficients M' that need to be compared.

[0113] The mutual inductance coefficient M in some groups (18 in the example) is consistent with the theoretical mutual inductance coefficient M' in the feature library, or is within the allowable error range. The grid corresponding to the theoretical mutual inductance coefficient M' is mapped through the feature library as the basic grid. At this time, a location where a detection receiving coil 51 is installed can be determined (here "one" refers to a location, and there can be three detection receiving coils 51 at this location). The basic grid is the location of the current detection receiving coil 51.

[0114] When another set of mutual inductance coefficients M is consistent with the theoretical mutual inductance coefficients M' in the feature library, another position can be determined, and a connection line can be determined based on the mapping of the two positions on the grid. When there is a third set of mutual inductance coefficients M, a triangle can be formed, because each position is relatively fixed to the position of the power receiving coil 65, thereby determining the position of the power receiving coil 65.

[0115] This method can easily know whether the vehicle is parked accurately.

[0116] Second type:

[0117] In this embodiment, it is necessary to determine the data of the alignment status in the previous step - at least one of the grids is reserved as the standard grid. When the basic grid and the standard grid are the same grid, it is the wireless charging alignment position; otherwise, the mobile route planning data is generated based on the orientation between the basic grid and the standard grid.

[0118] When the standard grid and the base grid are not the same, that is, there is no alignment, by mapping on the grid, we can know how to move the vehicle to reach the aligned position. Therefore, this method can realize the parking guidance function.

[0119] When the vehicle is manually driven, the above mapping on the grid is converted into deviation data or vehicle operation prompts (forward, backward, turn, etc.) and sent to the vehicle console or mobile phone App and other operation interfaces; when the vehicle is automatically parked or automatically driven, it can directly cooperate with the parking system to automatically adjust the vehicle. Finally, the electric vehicle is driven to the allowable deviation range between the power transmitting coil and the power transmitting receiving coil.

[0120] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made according to the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present invention.

Claims

1. A wireless charging system, comprising a transmitter (T) and a receiver (R), wherein the transmitter (T) at least comprises a transmitter power supply system (2) and a transmitter controller (3), and the receiver (R) at least comprises a receiver power supply system (6) and a receiver controller (7), characterized in that: The transmitting end (T) further comprises: a transmitting end detection system (1); The receiving end (R) further comprises: a receiving end detection system (5); The transmitting end detection system (1) comprises: a signal generator (11), a driver (12), a transmitting circuit (13) and a detection transmitting coil (14) which are connected in sequence; The receiving end detection system (5) comprises: a detection receiving coil (51), a detection circuit (56) and an auxiliary charging circuit, wherein the detection receiving coil (51) is connected to one of the detection circuit (56) and the auxiliary charging circuit; the auxiliary charging circuit comprises an auxiliary power supply (55), and the auxiliary power supply (55) is connected to the receiving end controller (7); The detection receiving coil (51) is arranged at least at two positions, respectively located on two sides of the receiving end power supply system (6); The detection transmitting coil (14) is arranged at least at one position; When the detection receiving coil (51) and the detection circuit (56) are connected, it is used to detect whether the transmitting end (T) and the receiving end (R) are within the working range. When they are within the working range, mutual inductance is generated between the detection transmitting coil (14) and the detection receiving coil (51); When the detection receiving coil (51) is connected to the auxiliary charging circuit, mutual inductance is generated between the detection transmitting coil (14) and the detection receiving coil (51); There are at most three detection receiving coils (51) at one location, and they are oriented in different directions; There are at most three detection and transmission coils (14) at one location, and they are oriented in different directions; The operating frequency of the detection transmitting coil (14) is different from the operating frequency of the transmitting end power supply system (2).

2. The wireless charging system according to claim 1, characterized in that: The transmitting circuit (13) has at least one transmitting loop; in each transmitting loop, one detecting transmitting coil (14) is connected; Each of the transmitting loops also includes a transmitting loop switch (TK) and a transmitting loop capacitor (TC) connected in series with the detection transmitting coil (14).

3. The wireless charging system according to claim 2, characterized in that: Define the X dimension, Y dimension and Z dimension based on a three-dimensional rectangular coordinate system; With two transmitting loops or three transmitting loops as a group, the directions of the detection transmitting coils (14) in the same group are not repeated in the X dimension, the Y dimension and the Z dimension.

4. The wireless charging system according to claim 1, characterized in that: The detection circuit (56) has at least one receiving circuit, and each receiving circuit is connected to one of the detection receiving coils (51); Each receiving loop also includes: a receiving loop switch (RK) and a receiving loop capacitor (RC) connected in series with the detection receiving coil (51).

5. The wireless charging system according to claim 4, characterized in that: Define the X dimension, Y dimension and Z dimension based on a three-dimensional rectangular coordinate system; Two receiving loops or three receiving loops are taken as a group, and the directions of the detection receiving coils (51) in the same group are not repeated in the X dimension, the Y dimension and the Z dimension.

6. The wireless charging system according to claim 1, characterized in that: The auxiliary charging circuit also includes: a working resonant network (52), a working rectifier (53), and a working filter (54) which are connected in sequence; The working resonant network (52) is connected to or disconnected from the detection receiving coil (51) via an auxiliary charging switch (WK).

7. The wireless charging system according to claim 4, characterized in that: The auxiliary charging circuit comprises: a working resonant network (52), a working rectifier (53), and a working filter (54) which are connected in sequence; The working resonant network (52) is connected to or disconnected from the detection receiving coil (51) via an auxiliary switch (WK); The receiving circuit switch (RK) and the auxiliary charging switch (WK) are the same switch, and the detection receiving coil (51) is selectively connected to the detection circuit (56) or to the auxiliary charging circuit.

8. The wireless charging system according to claim 1, characterized in that: The transmitting end (T) further comprises: a transmitting end controller (3) and a transmitting end communication system (4); The transmitter controller (3) is respectively connected to the transmitter power supply system (2) and the transmitter communication system (4).

9. The wireless charging system according to claim 1, characterized in that: The receiving end (R) further comprises: a receiving end controller (7) and a receiving end communication system (8); The receiving end controller (7) is respectively connected to the receiving end power supply system (6), the detection circuit (56), the auxiliary charging circuit, and the receiving end communication system (8); The receiving end communication system (8) is also connected to the auxiliary power supply (55).

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