Wireless charging system and detection device, detection method and charging method thereof

Abstract

The present invention discloses a wireless charging system and its detection device, detection method and charging method. The detection device includes: a coil matrix, a circuit matrix, a controller and a power supply. The circuit matrix is ​​connected to the coil matrix and the controller; the coil matrix includes a first coil group and a second coil group, the first coil group includes a plurality of first coils, and the second coil group includes a plurality of second coils; the first coil group and the second coil group are overlapped, and the non-covered area between any adjacent second coils is within the coverage area of ​​the first coil; the circuit matrix includes a first circuit and a second circuit; the power supply at least supplies power to the controller, the second circuit and the second coil group. The non-covered area of ​​the second coil is within the coverage area of ​​the first coil, ensuring that foreign objects in the area can be detected. At the same time, the second circuit has an independent power supply, which can realize the judgment of charging frequency changes, misalignment and other situations.

Description

Technical Field

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

[0002] Wireless charging technology for electric vehicles is safe, environmentally friendly, and easy to use. With the gradual popularization of technologies such as automatic parking, automatic driving, and intelligent connected vehicles, wireless charging has been widely recognized as a highly advantageous automatic charging method. However, when a metal foreign body appears above the transmitting coil of the wireless charging system, the metal foreign body will generate heat due to the eddy current effect, which will have a serious impact on the transmission of power in the system and may even cause safety hazards due to the sharp increase in temperature. Therefore, metal foreign body detection is an important protection function required for wireless charging transmitting coils and wireless charging technology. During wireless charging, in addition to considering the impact of foreign objects entering, it is also required to ensure that the receiving coil and the transmitting coil are aligned when the vehicle is parked to improve charging efficiency.

[0003] In the prior art, multiple parallel detection coils are generally used, and the detection coils are set between the transmitting coil and the receiving coil, and the detection coils are placed inside the plane where the energy transmitting coil is located. When there is a foreign object, the current, voltage or phase of the foreign object detection coil changes, and the foreign object detection sensor detects the foreign object based on the current, voltage or phase change of the foreign object detection coil. Of course, the foreign objects mentioned here mainly refer to metal foreign objects, and of course foreign objects of other conductive materials are also included.

[0004] When foreign objects are present at the adjacent edges of multiple coils, there is a problem of missed detection. At the same time, the detection coil is placed on the transmitting coil, and generates current and voltage through electromagnetic induction with the transmitting coil, and detects the current and voltage changes when foreign objects enter to achieve foreign object detection. However, when the electric vehicle is charging, the charging power of the transmitting coil will be adjusted with factors such as charging time, which will cause the foreign object detection coil to change, resulting in misjudgment. Summary of the invention

[0005] The present invention provides a wireless charging system and a detection device, a detection method and a charging method thereof, which can accurately detect foreign objects and avoid interference of other factors in judgment.

[0006] The detection device of the wireless charging system of the present invention includes: a coil matrix, a circuit matrix, a controller and a power supply, wherein the circuit matrix is ​​connected to the coil matrix and the controller; the coil matrix includes a first coil group and a second coil group, the first coil group includes a plurality of first coils, and the second coil group includes a plurality of second coils; the first coil group and the second coil group are overlapped, and the non-covered area between any adjacent second coils is within the coverage area of ​​the first coil; the circuit matrix includes a first circuit and a second circuit, the first circuit connects the first coil group and the controller, and the second circuit connects the second coil group and the controller; the power supply at least supplies power to the controller, the second circuit and the second coil group.

[0007] Preferably, the second circuit includes a second switch module, a second filter module and a second conversion module that are connected; the second switch module is respectively connected to each of the second coils to control the connection state of each of the second coils; the second filter module is connected to the second switch module to filter each of the connected second coils to form a second filtered signal; the second conversion module is connected to the second filter module to convert the second filtered signal into a second processed signal, and the second conversion module is also connected to the controller to send the second processed signal to the controller.

[0008] Preferably, the first circuit includes a first switch module, a first rectifier module and a first conversion module that are connected; the first switch module is respectively connected to each of the first coils to control the connection state of each of the first coils; the first rectifier module is connected to the first switch module to rectify each of the connected first coils to form a first rectified signal; the first conversion module is connected to the first rectifier module to convert the first rectified signal into a first processed signal, and the first conversion module is also connected to the controller to send the first processed signal to the controller.

[0009] Preferably, the second conversion module includes: a signal generator, a reference element, an access element and a signal processor; the signal generator, the reference element and the access element are connected in series, the signal processor is connected in parallel with the reference element, and the signal processor is also connected in parallel with the access element; wherein the access element contains the second filtering module; the signal processor generates the second processed signal.

[0010] Preferably, the reference element is at least one of a coil and a resistor.

[0011] Preferably, it also includes: a communicator connected to the controller.

[0012] A detection method for a wireless charging device, comprising obtaining a first electrical parameter value of each first coil through a first circuit; obtaining a second electrical parameter value of each second coil through a second circuit; prefabricating a first standard value for each first coil and a second standard value for the second coil; when the second electrical parameter value deviates from the second standard value and part of the first electrical parameter values ​​deviate from the first standard value, it is judged that there is a foreign object; when the second electrical parameter value deviates from the second standard value and all of the first electrical parameter values ​​meet the first standard value, it is judged that there is a foreign object; when the second electrical parameter value meets the second standard value and part of the first electrical parameter values ​​deviate from the first standard value, it is judged that there is a foreign object; when the second electrical parameter value meets the second standard value and part of the first electrical parameter values ​​deviate from the first standard value, it is judged that there is a foreign object; When the parameter value conforms to the second standard value and all the first electrical parameter values ​​are offset from the first standard value by a pre-made offset value, it is judged that the charging power has changed; when the second electrical parameter value conforms to the second standard value and the first electrical parameter value in a continuous area is offset from the first standard value, and in the initial stage of charging, it is judged that the alignment is not fully aligned; wherein the pre-made offset value refers to: when the charging power needs to change, the offset of all the first electrical parameters corresponding to the charging power change; the first electrical parameter value includes one or more of the voltage value, current value, inductance value, frequency value, and phase value; the second electrical parameter value includes one or more of the voltage value, current value, inductance value, frequency value, and phase value.

[0013] Preferably, when it is determined that the alignment is inaccurate, the voltage value of each of the first electrical parameter values ​​is obtained or calculated, and when all the voltage values ​​are within the voltage threshold range, charging continues, otherwise charging is not performed; when it is determined that there is a foreign object, an alarm is issued and / or charging is not performed.

[0014] The present invention also provides a detection method for a wireless charging device, comprising obtaining a second electrical parameter value of each second coil through a second circuit; prefabricating a second standard value of each second coil; and determining that there is a foreign object when the second electrical parameter value deviates from the second standard value.

[0015] The charging method of the wireless charging system of the present invention includes applying a small power to the transmitting coil when charging starts, and performing detection using the detection method of the wireless charging system described above.

[0016] The wireless charging system of the present invention comprises a transmitting coil and a housing, and is characterized in that it also comprises the above-mentioned detection device of the wireless charging system, and the detection device of the wireless charging system is arranged between the transmitting coil and the housing.

[0017] The detection device, detection method and charging method of the wireless charging system of the present invention have two coil groups, a first coil group and a second coil group, and the non-covered area of ​​the second coil is within the covered area of ​​the first coil, ensuring that foreign objects in the area can be detected. At the same time, the second circuit has an independent power supply, so it is less affected by the frequency change of the transmitting coil, and in conjunction with the first coil group, it can realize the judgment of charging frequency changes, misalignment and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a detection device of a wireless charging system of the present invention;

[0019] Figure 2 is a schematic diagram of a second conversion module in a detection device of a wireless charging system of the present invention;

[0020] Figure 3 It is a partial schematic diagram of the coil matrix in the detection device of the wireless charging system of the present invention.

[0021] Reference numerals:

[0022] Coil matrix A, circuit matrix B, controller C, power supply D, communicator E, first coil group 1, second coil group 2, first circuit 3, second circuit 4, first coil 11, second coil 21, first switch module 31, first rectifier module 32, first conversion module 33, second switch module 41, second filter module 42, second conversion module 43, signal generator 431, reference element 432, access element 433, signal processor 434. 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 detection device of the wireless charging system of the present invention (hereinafter referred to as the detection device) is shown in FIG. Figure 1 It includes: coil matrix A, circuit matrix B, controller C and power supply D. Circuit matrix B is connected to coil matrix A and controller C, and circuit matrix B can send the electrical parameters of coil matrix A to controller C in the form of electrical signals or other signals that controller C can recognize.

[0025] The coil matrix A includes a first coil group 1 and a second coil group 2, hereinafter collectively referred to as coil groups, both of which are composed of multiple coils: the first coil group 1 includes multiple first coils 11, and the second coil group 2 includes multiple second coils 21. The first coil 11 and the second coil 21 are collectively referred to as coils hereinafter.

[0026] The first coil group 1 and the second coil group 2 are stacked, and the non-covered area between any adjacent second coils 21 is within the coverage area of ​​the first coil 11. In other words, the identification blind area between the second coils 21 is covered by the first coil 11. As shown in Figure 3, in this more regular wiring method (arrangement method of the coils), a non-covered area, or identification blind area, is formed between every four second coils 21. This area is within the coverage area of ​​the first coil group 1, that is, within the identification area of ​​the first coil 11. In this way, foreign objects entering the identification blind area of ​​the second coil 21 will also be identified by the first coil 11.

[0027] Generally, the coil is wound, and because of the thickness (diameter) of the wire harness itself, it is bound to cause rounded corners, such as Figure 3 As shown, even a square coil will have arcs at the four corners, and the signals of multiple coils will produce cross interference, and a blind spot will appear at the intersection. Figure 3 The arrow Z in FIG. 1 shows the blind area. Figure 3 There are multiple blind areas at the junction of the second coil 21, and the blind areas are covered by the first coil 11 (shown by dotted lines in the figure for distinction). It should be noted that Figure 3 This is only for illustration and is not intended to limit the shape, arrangement, quantity, etc. of the first coil 11 and the second coil 21 .

[0028] The circuit matrix B includes a first circuit 3 and a second circuit 4, wherein the first circuit 3 connects the first coil group 1 and the controller C, and the second circuit 4 connects the second coil group 2 and the controller C. The first circuit 3 sends the electrical parameters of each first coil 11 in the first coil group 1 to the controller C. Correspondingly, the second circuit 4 sends the electrical parameters of each second coil 21 in the second coil group 2 to the controller C.

[0029] Generally, the electrical parameters of each coil are sent one by one, of course according to certain rules, to ensure that it is possible to determine which coil group the coil belongs to and its position, so as to provide better support for subsequent foreign object detection or judgment of other scenarios.

[0030] The power source D at least supplies power to the controller C, the second circuit 4 and the second coil group 2. That is to say, the second coil group 2 is powered by an independent power source D instead of obtaining power from the transmitting coil.

[0031] The detection device of the present application is mainly arranged at the transmitting coil end of the wireless charging system, and is arranged above the transmitting coil. For wireless charging of electric vehicles, the detection device is arranged at the ground end.

[0032] The second circuit 4 includes a second switch module 41, a second filter module 42 and a second conversion module 43 that are connected; the second switch module 41 is respectively connected to each second coil 21 to control the connection state of each second coil 21; the second filter module 42 is connected to the second switch module 41 to filter each connected second coil 21 to form a second filtered signal; the second conversion module 43 is connected to the second filter module 42 to convert the second filtered signal into a second processed signal, and the second conversion module 43 is also connected to the controller C to send the second processed signal to the controller C.

[0033] The second switch module 41 enables each second coil 21 to emit electrical parameters one by one. The purpose of the second switch module 41 is to distinguish the electrical parameters of each second coil 21 from each other to ensure subsequent judgment and use. The electrical parameters of any second coil 21 will be filtered by the second filter module 42 to form a second filtered signal. It can be known from the position where the above-mentioned detection equipment is placed that because it is on the transmitting coil, the transmitting coil will also affect the electrical parameters of the second coil 21. Therefore, the role of the second filter module 42 is to filter out the electrical signal formed by the electromagnetic induction of the second coil 21 and the transmitting coil. Filtering of different frequencies can be used here to filter out the influencing signal generated by the transmitting coil.

[0034] The second conversion module 43 is connected to the second filtering module 42 to convert the second filtered signal into a second processed signal. The second conversion module 43 is also connected to the controller C to send the second processed signal to the controller C.

[0035] The specific structure of the second conversion module 43 is described below. Figure 2 The second conversion module 43 includes: a signal generator 431, a reference element 432, an access element 433 and a signal processor 434; the signal generator 431, the reference element 432 and the access element 433 are connected in series, the signal processor 434 is connected in parallel with the reference element 432, and at the same time, the signal processor 434 is connected in parallel with the access element 433; wherein the access element 433 includes the second filtering module 42; the signal processor 434 generates a second processed signal.

[0036] Preferably, the power source D supplies power to the second coil group 2, which can be realized by the signal generator 431. The signal generator 431 supplies electric energy of specified electrical parameters (frequency, voltage, current, etc.) to the second coil group 2, and the electrical parameters are different from the electrical parameters of the transmitting coil, so that the electrical parameters of each second coil 21 are different from the electrical parameters induced by the transmitting coil, so as to be filtered by the second filtering module 42. The reference element 432 is at least one of the second coil and the resistor.

[0037] The purpose of the access element 433 is to substitute the electrical parameters of the second coil 21 into the second conversion module 43 and compare it with the reference element 432. Therefore, the access element 433 includes the second filter module 42, that is, the second filter module 42 is connected to the second conversion module 43, that is, the second filter module 42, the second filter signal is connected to the second conversion module 43, the second filter signal is compared with the electrical parameters of the reference element 432, and finally compared and processed by the signal processor 434 to generate the above-mentioned second processed signal. In principle, the structure, size and other parameters of each second coil 21 are the same, and the inductance and resistance of the reference element 432 and the access element 433 are also consistent. However, there may be deviations in the application, so the reference element 432 tries to keep the above consistency, and in the case of inconsistency, the predictability of the difference can be guaranteed. For example, due to different inductances, the expression of other electrical parameters may be affected, such as the period of the reference element 432 and the period of the access element 433 are different, but the two periods have a fixed difference, which can be detected, and the difference will be maintained as a criterion for judgment.

[0038] When working, the signal generator 431 generates a constant current sine wave, which is applied to the reference element and can also be applied to the second coil group 2, including each second coil 21. After the second coil 21 is connected to the constant current sine wave, the electrical parameters of each second coil 21 are counted into the second conversion module 43 under the cooperation of the second switch module 41 and the second filter module 42, and compared with the reference element 432. When there is no metal foreign matter within the effective range of the second coil group 2, the voltage amplitude and phase applied to the reference element 432 and each second coil 21 should be consistent (or in a fixed difference ratio. Consistency here does not mean that they are completely the same, but can also mean that they are within an acceptable range of variation. Here, the voltage amplitude and phase are both electrical parameters). When there is a metal foreign matter within the effective range of the second coil group 2, the voltage amplitude and phase of the second coil 21 at the corresponding position will differ from the reference element. When the difference value exceeds a certain threshold, it can be judged that there is a metal foreign matter above the transmitting coil, and the position of the metal foreign matter above the transmitting coil can be determined according to the position of the changed second coil 21.

[0039] The first circuit 3 is described below, which includes a first switch module 31, a first rectifier module 32 and a first conversion module 33 that are connected.

[0040] The first switch module 31 is respectively connected to each first coil 11 to control the connection state of each first coil 11; the first rectifier module 32 is connected to the first switch module 31 to rectify each connected first coil 11 to form a first rectified signal; the first conversion module 33 is connected to the first rectifier module 32 to convert the first rectified signal into a first processed signal. The first conversion module 33 is also connected to the controller C to send the first processed signal to the controller C.

[0041] The first switch module 31 and the second switch module 41 have similar functions. The first switch module 31 is to enable each first coil 11 to emit electrical parameters one by one so that each electrical parameter can be distinguished. The first rectifier module 32 rectifies the electrical parameters of each first coil 11 to form a first rectified signal. Subsequently, the first rectified signal is converted into a first processed signal that can be recognized by the controller C through the first conversion module 33.

[0042] The first processing signal and the second processing signal are sent to the controller C independently of each other.

[0043] Preferably, a communicator E is also included, which is connected to the controller C. The controller C determines whether there is a foreign object, the working condition of charging, etc. according to the first processing signal and the second processing signal, and sends the judgment result through the communicator E. For example, if a foreign object is detected, the relevant information is sent through the communicator E. The communicator E can be a reminder to personnel, such as sending it to the dashboard of the vehicle, mobile phone application, etc., to notify the driver (or other personnel). The communicator E can also communicate with other components, such as communicating with the battery module of the vehicle, or communicating with the receiving coil on the vehicle to turn off wireless charging. In other words, the communication objects of the communicator E can be multiple, as long as the information after detection, judgment and processing by the controller C is sent out, it can be called the function of the communicator E.

[0044] Taking electric vehicle wireless charging as an example, the ground end mainly includes the upper shell, transmitting coil, ferrite and bottom plate, etc. The transmitting coil is generally made of high-frequency Litz wire, and the upper shell and bottom plate are made of engineering plastics, which are mainly used to encapsulate the coil and improve the mechanical strength.

[0045] The detection equipment of the wireless charging system mentioned in the present application is installed between the upper shell and the transmitting coil. A metal sheet made of aluminum alloy is generally installed between the bottom plate and the ferrite to play the role of electromagnetic field shielding and heat conduction. After the coil is assembled, the inside will also be filled with epoxy resin potting glue to play the role of curing, insulation, heat conduction, waterproofing, etc. of the coil.

[0046] The two main parts of the detection equipment, namely the coil matrix A and the circuit matrix B mentioned above, are described in detail.

[0047] The coil matrix A is fixed to the inner surface of the upper shell, and the coil matrix A includes two coil groups, namely, the first coil group 1 and the second coil group 2, both of which are composed of a plurality of wound coils (the first coil 11 and the second coil 21). The first coil 11 and the second coil 21 may have the same structure, size, etc.

[0048] The first coil 11 and the second coil 21 are small-sized coils. The "small size" here refers to the transmission coil. Generally, the diameter of the first coil 11 and the second coil 21 (collectively referred to as coils) affects the detection accuracy. The size should be set according to the actual use requirements. The coil is composed of a detection coil wound by metal wire or printed on PCB. The shape can be circular, rectangular, polygonal or other regular shapes. The coil matrix A is laid as a whole above the transmission coil and other areas that need to be detected.

[0049] The circuit matrix B is arranged on the bottom plate at the bottom of the transmitting coil and outside the power transmission magnetic field.

[0050] Each first coil 11 of the first coil group 1 of the coil matrix A is individually connected to the first switch module 31, and each second coil 21 of the second coil group 2 of the coil matrix A is individually connected to the second switch module 41 of the detection circuit matrix B. The first switch module 31 and the second switch module 41 may be referred to as switch modules hereinafter. Both switch modules may cyclically switch coils through internal switch chips, and each time a corresponding coil is connected to the subsequent functional circuit (i.e., the subsequent first switch module 31, the first rectifier module 32, the first conversion module 33, the second switch module 41, the second filter module 42, the second conversion module 43, etc.).

[0051] The first coil 11 of the first coil group 1 is connected to the first rectifier module 32, and then connected to the first conversion module 33. During the wireless charging process, the magnetic field generated by the power transmission passes through each first coil 11 of the first coil group 1, and induced alternating current is generated inside each first coil 11. The alternating current signal (that is, the electrical parameter) is rectified by the first rectifier module 32 and converted into direct current. The first conversion module 33 converts the direct current voltage into a valid signal (that is, a signal that can be recognized by the controller C) and sends it to the controller C.

[0052] The second coil 21 of the second coil group 2 is connected to the second filtering module 42, preferably a high-order filtering module (high-order filter), and then connected to the second conversion module 43. The second filtering module 42 can filter out interference signals in the electrical parameters of the connected second coil 21, especially the AC signal generated by the power transmission magnetic field (i.e., the interference of the transmitting coil).

[0053] The second conversion module 43 is composed of a signal generator 431, a signal processor 434 (the signal processor 434 can be implemented by a signal processing circuit), a reference element 432, etc. The access element 433 and the reference element are connected in series, and the access element 433 includes the second filtering module 42, but the electrical parameters it reflects are the electrical parameters of the second coil 21, which can be simply understood as the second coil 21 is counted into the counting element 433.

[0054] The inductance and resistance of each second coil 21 when there is no metal foreign matter are set to be consistent with the reference element 432 (or to be in a fixed difference ratio. Consistent here does not mean just being completely identical, but can also mean being within an acceptable range of variation. The voltage amplitude and phase generated here are both electrical parameters). The signal generated by the signal generator 431 is applied to both ends of the reference element 432 and the second coil 21. Metal foreign matter can be equivalent to inductance and resistance, and when the metal foreign matter is close to the second coil 21, there is an equivalent mutual inductance between the inductance of the second coil 21 and the metal foreign matter. Therefore, when a metal foreign matter falls on a second coil 21, the equivalent inductance and resistance of the corresponding second coil 21 will change.

[0055] When there is interference in the signal (electrical parameters) on the second coil 21, such as the second filter module 42 cannot completely eliminate the interference of the power transmission magnetic field (interference of the transmitting coil), the phase and voltage amplitude of the sinusoidal signal on the reference element 432 and the second coil 21 may also have a certain deviation when there is no foreign matter, but this deviation value is fixed or regular and should be controlled within a certain range during design. When a metal foreign matter appears, the deviation exceeds a certain threshold (the threshold may be referred to as the second standard value hereinafter), and it can also be determined that there is a metal foreign matter above the transmitting coil.

[0056] The detection signal on the second coil group 2 is generated by an independent signal generator 431, with no or little interference from the power transmission magnetic field. When the signal of the second coil 21 deviates from the normal threshold, it can be determined that there is a metal foreign body; while the detection signal on the first coil group 1 is applied by the power transmission magnetic field (transmitting coil), and the change in its induced voltage may be caused by the presence of a metal foreign body, or it may be caused by the parking position being offset, or the change in the charging power of the wireless charging transmission. When there is a metal foreign body, if the foreign body covers multiple coils in the first coil group 1 and the second coil group 2, the foreign body can be found only by the second coil group 2; if the foreign body only covers the intersection of each second coil 21 in the second coil group 2, the second coil group 2 may not be able to find the foreign body, and the assistance of the first coil 11 is required. The induced voltage of the first coil 11 or several adjacent first coils 11 at the corresponding foreign body of the first coil group 1 will change, but the voltage of other first coils 11 will not change. The foreign body can also be found by the combination of the first coil group 1 and the second coil group 2.

[0057] When there is no metal foreign matter on the transmitting coil, but the parking position is offset, or the transmission power changes, the induced voltage of the first coil 11 of the first coil group 1 will also change, but this change is regular, that is, all coils or the first coil 11 of an area may change at the same time, but the second coil group 2 does not find foreign matter. At this time, it can be judged that there is no foreign matter, and the induced voltage of the coil of the first coil group 1 at this time is used as a judgment of the charging situation. The charging situation includes whether the alignment is accurate and whether there is a change in charging power. The change in charging power may be a charging strategy for wireless charging, which needs to be adjusted according to the saturation of the battery being charged, temperature, charging time, etc.

[0058] A detection method for a wireless charging system is described below, which can at least detect foreign objects, detect whether charging is aligned, and detect whether charging power changes. It should be noted that the "foreign objects" mentioned below mainly refer to metal foreign objects or conductive foreign objects.

[0059] The detection method needs to obtain the first electrical parameter of the first coil 11 and the second electrical parameter of the second coil 21. In combination with the above detection equipment, it can be known that directly using the first circuit 3 and the second circuit 4 is the most convenient and quickest way to obtain the above electrical parameters. The above first electrical parameter value includes the electrical parameters of each first coil 11, that is, the first electrical parameter is a set of data. Similarly, the second electrical parameter also includes the electrical parameters of each second coil 21. In addition, the first standard value of the first coil 11 (the first standard value of each first coil 11) and the second standard value of the second coil 21 (the second standard value of each second coil 21) are prefabricated. It should be noted that the "first" and "second" mentioned in the above "first electrical parameter", "second electrical parameter", "first standard value" and "second standard value" are for the convenience of distinction, and do not indicate that there is a data association between the two, especially without limiting the order of obtaining them one after another. The first standard value and the second standard value can be reference values ​​that are considered to be set, which can be adjusted with the change of power during the charging process, or they can be fixed values. That is, the first standard value and the second standard value may change with the charging process.

[0060] During the judgment process, the first electrical parameter value needs to be compared with the first standard value, and the second electrical parameter value needs to be compared with the second standard value. The following lists several judgment results.

[0061] 1. When the second electrical parameter value deviates from the second standard value and part of the first electrical parameter value deviates from the first standard value, it is determined that there is a foreign object. In other words, the foreign object is detected by the first coil 11 in the first coil group 1 and the second coil 21 in the second coil group 2 at the same time. In general applications, the presence of foreign objects mostly belongs to the type case.

[0062] 2. When the second electrical parameter value is offset from the second standard value and all the first electrical parameter values ​​meet the first standard value, it is judged that there is a foreign object. This situation may occur because the foreign object falls at the junction of the first coil 11, that is, in the blind area detected by the first coil group 1, and the first electrical parameter value meets the first standard value. Due to the way the first coil group 1 and the second coil group 2 are set, the foreign object in the blind area of ​​the first coil group 1 can be detected by the second coil group 2. Another possibility is that the electrical parameters of the first coil 11 itself are not completely stable and unchanged under the action of the transmitting coil, and there may be some fluctuations. The influence of the foreign object on the first electrical parameter may be masked by its own fluctuations and ignored. The above two are possibilities that may occur, and do not limit the application of this judgment. In general, even if the foreign object falls into the blind area of ​​the first coil group 1, it will also affect the first coil 11 due to the conductivity of the foreign object.

[0063] 3. When the second electrical parameter value meets the second standard value and some of the first electrical parameter values ​​deviate from the first standard value, it is determined that there is a foreign object. This situation indicates that the foreign object falls into the detection blind area of ​​the second coil group 2, but can be detected by the first coil 11 of the first coil group 1.

[0064] 4. When the second electrical parameter value meets the second standard value, and all the first electrical parameter values ​​are offset from the first standard value by a pre-set offset value, it is determined that the charging power changes. In this case, no foreign matter has entered, and it is a normal charging power adjustment during the charging process. Because the power supply D supplies power to the signal generator 431 and is loaded onto the second coil 2, the power adjustment at the transmitting coil has limited effect on the second coil group 2. Even if there is an effect, it will be filtered out by the second filter module 42 because the power supply frequency at the transmitting coil is different from the frequency of the electricity applied to the second coil group 2.

[0065] Of course, in this case, the offset of the first electrical parameter has a preset offset value, which is related to the power adjustment data. The offset of the first electrical parameter is regular and predictable, otherwise it is not considered as a judgment of charging power change. Irregular changes, that is, no changes with pre-set offsets, may be caused by foreign objects entering, or foreign objects entering during the charging power change process. These are all manifestations that do not conform to the judgment of charging power change.

[0066] The prefabricated offset value is the offset of all first electrical parameters corresponding to the change of charging power only when the charging power needs to change. There may be slight differences between the electrical parameters of each first coil 11, but for the charging power change rate, the effect of this change on each first coil 11 is the same, so they have the same change law, so the offset value can be prefabricated. For example, when the charging power is reduced by 50%, the change in the electrical parameters of each first coil 11 is also a 50% power reduction, and the prefabricated offset value is about 50%. It should be noted that this is only an example and does not mean that the change in charging power is equal to the change in charging power of the first coil 11. The prefabricated offset value preferably adopts a range value. The change in electrical parameters is more affected, so it is necessary to have a fault tolerance space, and the specific range ratio should be set according to actual needs. And the prefabricated offset value of each first coil 11 is independent, which is related to the position, size, etc. of the first coil 11.

[0067] The charging power change is the power change that exists in the normal operation of the wireless charging system. The above-mentioned first standard value and second standard value may change with the charging process and may also occur in the process. When the charging power changes, the first standard value can change with it to ensure the subsequent comparison with the first electrical parameter. Of course, the first standard value can also remain unchanged, but when compared with the first electrical parameter, the setting of the offset value changes so that the judgment result can conform to the law of charging parameter changes. It should be noted that in this process, more first standard values ​​change. For the second standard value, because the second coil group 2 is not suitable for the transmitting coil to obtain electrical energy, it is powered by a stable power supply D (or signal generator 431), so it is not necessary to consider whether the second standard value changes, and it can be set according to actual needs.

[0068] 5. When the second electrical parameter value meets the second standard value, and the first electrical parameter value in the continuous area is offset from the first standard value, and in the initial stage of charging, it is judged that the alignment is inaccurate. For wireless charging of automobiles, it may be that the charging position is not aligned when parking. In this case, the formal charging has not yet started, so this judgment needs to be carried out in the initial stage of charging. Taking electric vehicles as an example, after the vehicle is parked, the initial stage of charging begins. This initial stage is a necessary process for the wireless charging system. For technicians in the field of wireless charging, the principle is known. In this initial stage, the transmitting coil will operate at low power. Low power refers to power that is far less than normal operation. The working power is different for different charging products, so the specific power value will not be limited, but the approximate range can be less than 10% of the working power. It should be noted that the judgment of the misalignment is limited to the initial stage of charging. The judgment during the charging process can be achieved by other components or structures of the wireless charging system.

[0069] The continuous area mentioned in the above “the first electrical parameter value in the continuous area is offset from the first standard value” may be the entire area, that is, the first electrical parameter values ​​of all the first coils 11 may be changed. This change is different from the change with a pre-set value in the fourth type. This change has no pre-set value and is caused by misalignment.

[0070] Among the above five types of judgment, except the fifth type used in the initial stage, the remaining four types can be judged at any stage of charging and can be throughout the entire wireless charging process.

[0071] The first electrical parameter value includes one or more of a voltage value, a current value, an inductance value, and a frequency value; the second electrical parameter value includes one or more of a voltage value, a current value, an inductance value, and a frequency value. And the electrical parameters of each first coil 11 and the electrical parameters of the second coil 21 are independent. Each first coil 11 has a unique corresponding first standard value. Each second coil 21 also has a unique corresponding second standard value. The first standard value and the second standard value are preferably range values ​​to provide fault tolerance. The above-mentioned "offset" is also for the range value. It is "offset" only when it exceeds the range, otherwise it is "compliant". And in different working states, especially when the charging power changes, the first standard value and the second standard value may change. In other words, the function of the first standard value and the second standard value is to provide a comparison standard for each coil, and the range of the specific standard can be adjusted as long as the occurrence of the offset can be determined.

[0072] There will also be corresponding processing methods for the results of the above five judgments.

[0073] When it is judged to be misaligned, the voltage value of each first electrical parameter value is obtained or calculated. When all voltage values ​​are within the voltage threshold range, charging continues, otherwise not charging. In other words, misalignment also has a fault tolerance range. Misalignment of a small distance does not affect charging and there is no safety hazard, so charging can be performed. Otherwise, it cannot be charged. When it is judged that there is a foreign object, an alarm is issued and / or charging is not performed. The "not charging" here includes two meanings. For the initial stage, when misalignment is detected and the above voltage value is not within the voltage threshold, not charging means that the subsequent charging function will no longer be performed. For charging that has already started (non-initial stage), if a foreign object is detected, charging is stopped. The above-mentioned acquisition or calculation of the voltage value of the first electrical parameter value is a preferred method, and is not limited to the use of voltage values. Other electrical parameters that can reflect the corresponding title can also be applied to this application.

[0074] In addition to the above five judgments, the present application also provides a simpler detection method for wireless charging equipment, which includes obtaining the second electrical parameter value of each second coil 21 through a second circuit; prefabricating the second standard value of each second coil; and judging that there is a foreign object when the second electrical parameter value deviates from the second standard value.

[0075] This method is similar to the above method, but is simpler. As long as the second electrical parameter deviates from the second standard value, it can be judged that there is a foreign object, and the judgment of charging power change, misalignment, etc. can be omitted. The present invention also discloses a charging method for a wireless charging system, including:

[0076] When charging starts, a low power is applied to the transmitting coil and the detection method of the wireless charging system is used for detection. That is, each of the above five judgments can be performed when charging starts. When charging starts, that is, the initial stage of charging, it runs at a low power. Only when there is no alarm or no charging action in these five judgments, will charging continue.

[0077] During the charging process, the specified power is used. At this time, the alignment work has been completed in the above judgment. Only when there is no problem with the alignment, the subsequent charging action will be entered. In the subsequent charging process, the above judgments 1-4 are used, and the alignment judgment is no longer performed. Of course, it does not exclude the wireless charging system from judging the alignment of the charging process in other ways, but the above judgment method 5 is not applicable.

[0078] Finally, the present invention also provides a wireless charging system, which includes a transmitting coil and a housing, and also includes the detection device of the wireless charging system, and the detection device of the wireless charging system is arranged between the transmitting coil and the housing. The detection device of the wireless charging system used can use the above detection method. The wireless charging system can also use the above charging method.

[0079] 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 detection device for a wireless charging system, characterized in that: include: A coil matrix (A), a circuit matrix (B), a controller (C) and a power supply (D), wherein the circuit matrix (B) is connected to the coil matrix (A) and the controller (C); The coil matrix (A) comprises a first coil group (1) and a second coil group (2), the first coil group (1) comprising a plurality of first coils (11), and the second coil group (2) comprising a plurality of second coils (21); the first coil group (1) and the second coil group (2) are stacked, and a non-covered area between any adjacent second coils (21) is within a covered area of ​​the first coil (11); The circuit matrix (B) comprises a first circuit (3) and a second circuit (4), the first circuit (3) connecting the first coil group (1) and the controller (C), and the second circuit (4) connecting the second coil group (2) and the controller (C); The power source (D) supplies power to at least the controller (C), the second circuit (4) and the second coil group (2); The second circuit (4) comprises a second conversion module (43), the second conversion module (43) comprises a signal generator (431), the signal generator (431) generates a constant current sine wave, and the constant current sine wave is applied to the second coil group (2); The detection signal on the first coil set (1) is applied by the power transmission magnetic field.

2. The detection device of the wireless charging system according to claim 1, characterized in that: The second circuit (4) comprises a second switch module (41), a second filter module (42) and a second conversion module (43) which are connected; The second switch module (41) is respectively connected to each of the second coils (21) to control the connection state of each of the second coils (21); The second filtering module (42) is connected to the second switch module (41) to filter each of the connected second coils (21) to form a second filtering signal; The second conversion module (43) is connected to the second filtering module (42) to convert the second filtered signal into a second processed signal. The second conversion module (43) is also connected to the controller (C) to send the second processed signal to the controller (C).

3. The detection device of the wireless charging system according to claim 1, characterized in that: The first circuit (3) comprises a first switch module (31), a first rectifier module (32) and a first conversion module (33) which are connected; The first switch module (31) is respectively connected to each of the first coils (11) to control the connection state of each of the first coils (11); The first rectifier module (32) is connected to the first switch module (31) to rectify each of the connected first coils (11) to form a first rectified signal; The first conversion module (33) is connected to the first rectifier module (32) to convert the first rectifier signal into a first processed signal. The first conversion module (33) is also connected to the controller (C) to send the first processed signal to the controller (C).

4. The detection device of the wireless charging system according to claim 2, characterized in that: The second conversion module (43) comprises: a signal generator (431), a reference element (432), an access element (433) and a signal processor (434); The signal generator (431), the reference element (432) and the access element (433) are connected in series, the signal processor (434) is connected in parallel with the reference element (432), and the signal processor (434) is also connected in parallel with the access element (433); wherein: The access element (433) includes the second filtering module (42); The signal processor (434) generates the second processed signal.

5. The detection device of the wireless charging system according to claim 4, characterized in that: The reference element (432) is at least one of a coil and a resistor.

6. A detection method for a wireless charging system, characterized in that: include: The signal generator (431) generates a constant current sine wave, and the constant current sine wave is applied to the second coil group (2); The detection signal on the first coil group (1) is applied by a power transmission magnetic field; the first electrical parameter value of each first coil (11) is obtained through the first circuit (3); Acquiring a second electrical parameter value of each second coil (21) through a second circuit (4); Prefabricating a first standard value of each of the first coils (11) and a second standard value of the second coils (21); When the second electrical parameter value deviates from the second standard value, and part of the first electrical parameter value deviates from the first standard value, it is determined that there is a foreign object; When the second electrical parameter value deviates from the second standard value and all the first electrical parameter values ​​meet the first standard value, it is determined that there is a foreign object; When the second electrical parameter value meets the second standard value and part of the first electrical parameter value deviates from the first standard value, it is determined that there is a foreign object; When the second electrical parameter value meets the second standard value, and all the first electrical parameter values ​​are offset from the first standard value by a preset offset value, it is determined that the charging power changes; When the second electrical parameter value meets the second standard value, and the first electrical parameter value in the continuous area deviates from the first standard value, and in the initial stage of charging, it is determined that the alignment is inaccurate; The prefabricated offset value refers to: when the charging power needs to be changed, the offset of all first electrical parameters corresponding to the change of the charging power; The first electrical parameter value includes one or more of a voltage value, a current value, an inductance value, a frequency value, and a phase value; The second electrical parameter value includes one or more of a voltage value, a current value, an inductance value, a frequency value, and a phase value.

7. The detection method of the wireless charging system according to claim 6, characterized in that: When it is determined that the alignment is inaccurate, the voltage value of each of the first electrical parameter values ​​is obtained or calculated, and when all the voltage values ​​are within the voltage threshold range, charging continues, otherwise charging is not performed; When it is determined that there is a foreign object, an alarm is issued and / or charging is stopped.

8. A charging method for a wireless charging system, characterized in that: include: When charging starts, a low power is applied to the transmitting coil, and detection is performed using the detection method of the wireless charging system described in any one of claims 6 to 7.

9. A wireless charging system, comprising a transmitting coil and a housing, characterized in that: It also includes a detection device for a wireless charging system according to any one of claims 1 to 5, wherein the detection device for the wireless charging system is arranged between the transmitting coil and the housing.

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