CN111835095A

CN111835095A - Foreign matter detection device and wireless charging transmitting terminal equipment

Info

Publication number: CN111835095A
Application number: CN202010565349.5A
Authority: CN
Inventors: 陈双全; 武志贤; 刘彦丁
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2020-10-27

Abstract

The application provides a foreign matter detection device, which is arranged between a power transmitting device and a power receiving device. The foreign matter detection device comprises an excitation source, a resonance module and a detection control module, wherein the resonance module is respectively connected with the excitation source and the detection control module; the resonance module comprises at least two resonance units which are connected in parallel, one resonance unit comprises an inductance coil, a first capacitor and a change-over switch, the inductance coil of any resonance unit is connected with the first capacitor in parallel to obtain a resonance network, and the resonance network of any resonance unit is connected with the change-over switch in series; the inductance coil of any resonance unit and the inductance coils of at least one other resonance unit form a decoupling coil group, and the mutual inductance coefficient between the inductance coils in the decoupling coil group is zero; the excitation source provides an excitation current; the detection control module is used for determining whether foreign matters exist between the power transmitting device and the power receiving device. By adopting the method and the device, the stability of foreign matter detection can be enhanced, and the safety of foreign matter detection is high.

Description

Foreign matter detection device and wireless charging transmitting terminal equipment

Technical Field

The application relates to the technical field of electromagnetic induction, in particular to a foreign matter detection device and wireless charging transmitting terminal equipment.

Background

The magnetic coupling type wireless charging is to realize the transfer of electric energy by taking a coupled electromagnetic field as a medium, and a wireless charging system generally comprises two separated components, namely a power transmitting device and a power receiving device, wherein the power transmitting device is connected with a power supply, and the power receiving device is connected with a load. The power transmitting device and the power receiving device transmit energy through electromagnetic induction between the transmitting coil and the receiving coil, an air gap is formed between the transmitting coil and the receiving coil, and when metal foreign matters enter the air gap, the electromagnetic induction between the transmitting coil and the metal foreign matters can generate an eddy current effect on the metal foreign matters, so that the temperature of the metal foreign matters is increased rapidly, and dangers such as fire disasters are possibly caused. Therefore, when charging a device such as a vehicle by a wireless charging system, it is necessary to detect a metal foreign object in order to secure safety of the wireless charging system and the device such as the vehicle.

The inventor of this application discovers in research and practice process, and prior art carries out the foreign matter through a plurality of foreign matter detection coils and detects, and foreign matter detection coil integration is on power transmitting device's transmitting coil, and power transmitting device's transmitting coil during operation, and the magnetic field of transmitting coil can be induced to foreign matter detection coil, can have induced voltage on the foreign matter detection coil this moment. In the foreign matter detection process, if the foreign matter detection coil is switched, the broken foreign matter detection coil can be changed into no current from a large current in a short time, and at the moment, a very large peak voltage can be generated on the foreign matter detection coil, so that the foreign matter detection fails due to the fact that the change-over switch of the foreign matter detection coil is easily damaged, the stability of the foreign matter detection is poor, and the safety is low.

Disclosure of Invention

The application provides a foreign matter detection device and wireless transmitting terminal equipment that charges can strengthen the stability that the foreign matter detected, and the security that the foreign matter detected is high, and the suitability is strong.

In a first aspect, the present application provides a foreign object detection apparatus disposed between a power transmitting apparatus and a power receiving apparatus of a wireless charging system. Here, the foreign object detection device may be integrated in a power transmitting coil of the wireless charging system and the foreign object detection device may be disposed at a side of the power transmitting coil facing the power receiving coil. Alternatively, the foreign object detection device may be integrated in a power receiving coil of the wireless charging system and the foreign object detection device may be disposed at a side of the power receiving coil facing the power transmitting coil. The foreign matter detection device comprises an excitation source, a resonance module and a detection control module, wherein the resonance module is respectively connected with the excitation source and the detection control module; the resonance module comprises at least two resonance units which are connected in parallel, one resonance unit comprises an inductance coil, a first capacitor and a change-over switch, the inductance coil of any resonance unit is connected with the first capacitor in parallel to obtain a resonance network, and the resonance network of any resonance unit is connected with the change-over switch in series. The inductance coil of any resonance unit and the inductance coil of at least one other resonance unit in at least two resonance units form a decoupling coil group, and the mutual inductance coefficient between the inductance coils in the decoupling coil group is zero. The excitation source is used for providing excitation current for the resonance module; and the detection control module is used for determining whether foreign matters exist between the power transmitting device and the power receiving device according to the electrical parameters of each resonant network in the resonant module under the action of the excitation current provided by the excitation source.

In the foreign matter detection device that this application provided, because mutual decoupling zero between each inductance coils, the voltage stress on the change over switch is showing and is reducing when resonant network switches over to effectively protected change over switch can not overvoltage damage, improved foreign matter detection device's circuit stability, the security that the foreign matter detected is higher, thereby improved and carried out the stability that the foreign matter detected based on this foreign matter detection device, the suitability is strong. The foreign matter detection device judges whether metal foreign matters exist in the area covered by the inductance coil of the resonant network or not through detecting the voltage at the two ends of the resonant network, and the foreign matter detection device is simple to operate and high in applicability. The foreign matter detection device can also obtain the change of impedance through the voltage at two ends of the resonance network and the current flowing through the resonance network, and the accuracy rate of judging whether the area covered by the inductance coil has the metal foreign matter or not through the change of the impedance is higher, and the flexibility is high.

With reference to the first aspect, in a first possible implementation manner, the inductance coil of any one of the resonance units is an 8-shaped coil, and current flows in two turns of the 8-shaped coil are opposite. Here, the 8-shaped coil is formed by winding the coil in the inductor coil in an 8-shaped winding manner, so that magnetic fields of two turns in the inductor coil are mutually cancelled. The shape of the inductance coil can be rectangular, square, hexagonal, octagonal, circular and the like.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner, the decoupling coil set includes two inductance coils, and magnetic fields of the two inductance coils cancel each other and are arranged in a matrix of the decoupling coils in two rows or two columns. Here, two figure-8 coils (e.g. figure-8 coil (r) and figure-8 coil (r)) may form a vertical column matrix, and figure-8 coil (r) may also form a vertical row matrix, where the positions of figure-8 coil (r) and figure-8 coil (r) may be interchanged. Here, the up-down vertical may be a vertical along the y-direction of the coordinate axis, and the left-right vertical may be a vertical along the x-direction of the coordinate axis. It is understood that the two inductors may be arranged in a matrix, such that the coil planes of the two inductors are on the same plane, for example, two figure-8 coils are both laid on the same table or the same PCB. The 8-shaped coil I and the 8-shaped coil II can be perpendicular to each other, and the central axes of the two 8-shaped coils can be perpendicular to each other.

With reference to the first possible implementation manner of the first aspect, in a third possible implementation manner, the decoupling coil set includes one first inductance coil and two second inductance coils; the two second inductance coils are arranged into an inductance coil group, and the magnetic field directions of the two second inductance coils in the inductance coil group are the same; the magnetic field of the inductance coil group and the magnetic field of the first inductance coil are mutually offset and are arranged in a decoupling coil matrix of two rows or two columns in a matrix manner. Here, the two second inductor coils may be arranged in parallel as one inductor coil group.

With reference to the second possible implementation manner of the first aspect or the third possible implementation manner of the first aspect, in a fourth possible implementation manner, the inductor coils of each of the resonance units form at least two decoupling coil sets; the at least two decoupling coil sets are arranged in a matrix in a multi-row and/or multi-column coil matrix, and the magnetic fields of two inductance coils in adjacent rows and/or adjacent columns in the coil matrix are mutually counteracted.

With reference to the second possible implementation manner of the first aspect or the third possible implementation manner of the first aspect, in a fifth possible implementation manner, the inductor coils of each of the resonance units form at least two decoupling coil sets; the at least two decoupling coil groups are arranged in a laminated mode to form at least two layers of coil matrixes, and magnetic fields of two adjacent inductance coils at the same positions of an upper layer and a lower layer in the coil matrixes are mutually offset.

With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner, an upper layer inductor coil and a lower layer inductor coil of the coil matrix are overlapped; or the upper layer inductance coil and the lower layer inductance coil of the coil matrix are partially overlapped. When the decoupling coil matrixes of the upper layer and the lower layer are stacked together, a single-layer detection blind area can be eliminated. Optionally, when the decoupling coil matrixes of the upper layer and the lower layer are stacked together, the decoupling coil matrixes of the upper layer and the lower layer can be staggered by a certain distance in the stacking process, so that a detection blind area when the coil matrixes are single layers can be eliminated better.

With reference to any one of the first to the sixth possible implementation manners of the first aspect, in a seventh possible implementation manner, the excitation source includes a power source, a first switch, a second switch, a first inductor, and a third capacitor; the first switch and the second switch are connected in series and then connected in parallel at two ends of the power supply, one end of the first inductor is connected with the first switch and the second switch respectively, the other end of the first inductor is connected with the third capacitor and serves as one end of the excitation source to be connected with the resonance module, and the other end of the third capacitor is connected with the power supply and the second switch respectively and serves as the other end of the excitation source to be connected with the resonance module. Here, the power source, the first switch, the second switch, the first inductor, and the third capacitor form a current source generator, which provides a current at port A, B, and AB is equivalent to an excitation source.

With reference to the seventh possible implementation manner of the first aspect, in an eighth possible implementation manner, each resonant unit further includes a second capacitor, and an inductor of each resonant unit is connected in series with the second capacitor and then connected in parallel with the first capacitor to obtain a resonant network of each resonant unit. Here, the series capacitances (e.g. capacitances Cc1, Cc2, … …, Ccn) added on the branches of the respective inductors (e.g. inductors L1, L2, … …, Ln) on the respective resonant networks (e.g. resonant cell 1, resonant cell 2, … …, resonant network 1 in resonant cell n, resonant network 2, … …, resonant network n) can be used to adjust the inductance of inductors L1, L2, … …, Ln. When inductor L1 is connected in series with capacitor Cc1, the equivalent inductance of inductor L1 is

In this case, the equivalent inductance of the inductor L1 may be used to calculate the impedance of the parallel resonant network.

With reference to the seventh possible implementation manner of the first aspect or the eighth possible implementation manner of the first aspect, in a ninth possible implementation manner, the excitation source further includes a fifth capacitor, and the third capacitor is connected after the first inductor and the fifth capacitor are connected in series. Here, the fifth capacitor Cs1 may be used to adjust the inductance of the first inductance Lm. When the first inductor Lm is connected in series with the fifth capacitor Cs1, the equivalent inductance of the first inductor Lm is

Where ω is the resonant angular frequency, Lm is the inductance of the first inductor Lm, and Cs1 is the capacitance of the fifth capacitor Cs 1.

With reference to the seventh possible implementation manner of the first aspect or the eighth possible implementation manner of the first aspect, in a tenth possible implementation manner, the excitation source further includes a sixth capacitor, one end of the sixth capacitor is connected to the first inductor and the third capacitor, respectively, and the other end of the sixth capacitor, serving as one end of the excitation source, is connected to the resonance module. Here, the sixth capacitance Cs2 is a dc blocking capacitance, and plays a role in protecting the resonant network.

With reference to the seventh possible implementation manner of the first aspect or the eighth possible implementation manner of the first aspect, in an eleventh possible implementation manner, the excitation source further includes a fifth capacitor and a sixth capacitor, the first inductor and the fifth capacitor are connected in series and then connected to the third capacitor, one end of the sixth capacitor is connected to the fifth capacitor and the third capacitor, respectively, and one end of the sixth capacitor, which serves as the excitation source, is connected to the resonance module. Here, the fifth capacitor and the sixth capacitor added to the excitation source may be added separately or simultaneously, and the adjusting capacitor of the inductor in the parallel resonant network may also be added separately. The fifth capacitor, the sixth capacitor and the adjusting capacitor of the inductance coil in the parallel resonant network can be added in various combinations, and the operation is flexible.

In a second aspect, the present application provides a wireless charging transmitting terminal device, which includes a power transmitting device and the foreign object detection device provided in the first aspect, where the power transmitting device includes a power transmitting coil, and the foreign object detection device is disposed on a side of the power transmitting coil facing a wireless charging power receiving device. Here, the power transmitting device may also be referred to as a wireless charging transmitting device, and the wirelessly charged power receiving device may also be referred to as a wireless charging receiving device. The wireless charging receiving device comprises a power receiving coil, and the foreign matter detection device can be arranged on one side of the power transmitting coil facing the power receiving coil.

Drawings

Fig. 1 is a schematic diagram of an architecture of a wireless charging system provided in the present application;

fig. 2 is a schematic structural diagram of a wireless charging system provided in the present application;

FIG. 3 is a schematic view of a position of the foreign object detection apparatus provided in the present application;

fig. 4 is a schematic circuit configuration diagram of a wireless charging system and a foreign object detection device provided in the present application;

FIG. 5 is a circuit diagram of a foreign object detection apparatus provided in the present application;

fig. 6 is an equivalent circuit schematic diagram of a foreign object detection apparatus provided in the present application;

FIG. 7 is another circuit schematic of the foreign object detection apparatus provided herein;

FIG. 8 is another circuit schematic of the foreign object detection apparatus provided herein;

fig. 9 is a schematic diagram of a winding manner and a direction of magnetic force lines of the 8-shaped coil provided by the present application;

FIG. 10 is a schematic diagram of a decoupling coil assembly provided herein;

FIG. 11 is another schematic structural view of a decoupling coil assembly provided herein;

FIG. 12 is another schematic structural view of a decoupling coil assembly provided herein;

FIG. 13 is another structural schematic of a de-coupling coil assembly provided herein;

FIG. 14 is another schematic structural view of a decoupling coil assembly provided herein;

FIG. 15 is another schematic structural view of a decoupling coil assembly provided herein;

FIG. 16 is another schematic structural view of a decoupling coil assembly provided herein;

FIG. 17 is another structural schematic of a de-coupling coil assembly provided herein;

FIG. 18 is another structural schematic of a de-coupling coil assembly provided herein;

FIG. 19 is another structural schematic of a de-coupling coil assembly provided herein;

FIG. 20 is a schematic view of an arrangement of an inductor coil in the foreign object detection apparatus;

fig. 21 is a schematic view of an embodiment of a foreign object detection method provided in the present application;

fig. 22 is a schematic diagram of another embodiment of the foreign object detection method provided in the present application.

Detailed Description

The application provides a foreign matter detection device is applicable to electric automobile's wireless field of charging, also is applicable to all other fields of using wireless charging technique outside the electric automobile, for example mobile terminal's such as panel computer wireless field of charging, or intelligent robot, electric fork truck etc. wireless field of charging etc. do not do the restriction here. In other words, the foreign object detection device provided by the application can be applied to a wireless charging system of an electric vehicle, a wireless charging system of a mobile device such as a tablet computer, or a wireless charging system of an intelligent robot or an electric forklift, and can be specifically determined according to an actual application scenario, which is not limited herein. For convenience of description, the foreign object detection device and the foreign object detection method based on the foreign object detection device provided by the present application will be exemplified by a wireless charging system applied to an electric vehicle.

With the shortage of energy and the aggravation of environmental pollution in modern society, electric vehicles have been widely paid attention to as new energy vehicles once they are launched. The electric automobile is a vehicle which takes a vehicle-mounted power supply as power, utilizes a motor to drive wheels to run and meets various requirements of road traffic and safety regulations. A battery charging method for an electric vehicle generally includes: contact charging and wireless charging. The contact charging adopts the metal contact of a plug and a socket to conduct electricity, and the wireless charging realizes the transmission of electric energy by taking a coupled electromagnetic field as a medium. Compared with contact charging, wireless charging has the advantages of convenience in use, no spark, no electric shock hazard, no mechanical abrasion, adaptability to various severe environments and weathers, convenience in realizing unmanned automatic charging, movable charging and the like, and can become the mainstream mode of charging of future electric vehicles. The following describes an example of a wireless charging system applied to an electric vehicle, and an example of an architecture of the wireless charging system to which the foreign object detection apparatus provided in the present application is applied is described.

Architecture of the wireless charging system:

referring to fig. 1, fig. 1 is a schematic diagram of an architecture of a wireless charging system provided in the present application. As shown in fig. 1, the wireless charging system may include at least: an electric vehicle 100 and a wireless charging station 101. The electric vehicle 100 may include a wireless charging receiving apparatus 1000, and the wireless charging station 101 may include a wireless charging transmitting apparatus 1010. Currently, the wireless charging system performs a charging process on the electric vehicle by using a wireless charging receiving device 1000 located in the electric vehicle 100 and a wireless charging transmitting device 1010 located in the wireless charging station 101 to perform a non-contact charging. Here, the wireless charging receiving device 1000 may also be referred to as a power receiving device, and the wireless charging transmitting device 1010 may also be referred to as a power transmitting device, which may be determined according to an actual application scenario, and is not limited herein.

Optionally, in some possible embodiments, the wireless charging station 101 may be a fixed wireless charging station, a fixed wireless charging parking space, or a wireless charging road, and may be determined according to an actual application scenario, which is not limited herein. The wireless charging transmitting device 1010 may be disposed on the ground or buried under the ground (fig. 1 shows a case where the wireless charging transmitting device 1010 is buried under the ground), and may wirelessly charge the electric vehicle 100 located above the wireless charging transmitting device 1010. The wireless charging receiving device 1000 may be specifically integrated into the bottom of the electric vehicle 100, and when the electric vehicle 100 enters the wireless charging range of the wireless charging transmitting device 1010, the electric vehicle 100 may be charged in a wireless charging manner. The power receiving coil and the rectifying circuit of the wireless charging receiving device 1000 may be integrated together, or may be separated, and when separated, the rectifying circuit is usually placed in the vehicle, and fig. 1 shows that the power receiving coil and the rectifying circuit are integrated together. The wireless charging transmitter 1010 also has two ways of integrating and separating a power transmitting coil and an inverter circuit, and fig. 1 shows a form that the power transmitting coil and the inverter circuit are integrated together.

Optionally, in some feasible embodiments, the non-contact charging may be that the wireless charging receiving device 1000 and the wireless charging transmitting device 1010 perform wireless energy transmission in a magnetic field coupling manner, specifically may be in an electromagnetic induction manner and a magnetic resonance manner, and may be determined according to an actual application scenario, which is not limited specifically herein. Optionally, the electric vehicle 100 and the wireless charging station 101 may also be charged bidirectionally, that is, the wireless charging station 101 charges the electric vehicle 100 through the power supply, or discharges the power supply from the electric vehicle 100, which may be determined according to an actual application scenario, and is not limited herein. The structures of the wireless charging transmitting device and the wireless charging receiving device in the wireless charging system shown in fig. 1 will be described below with reference to fig. 2.

The structures of the wireless charging transmitting device and the wireless charging receiving device in the wireless charging system are as follows:

referring to fig. 2, fig. 2 is a schematic structural diagram of a wireless charging system provided in the present application. The wireless charging system provided by the present application includes the wireless charging receiving apparatus 1000 and the wireless charging transmitting apparatus 1010 in the wireless charging system shown in fig. 1. The wireless charging receiver 1000 and the wireless charging transmitter 1010 transfer energy through electromagnetic induction between the transmitter coil and the receiver coil.

In some possible embodiments, the wireless charging transmitting apparatus 1010 includes: the system comprises a transmission conversion module 1011, a power transmission module 1012, a transmission control module 1013 connected with the transmission conversion module 1011 and the power transmission module 1012, a transmission communication module 1014 connected with the transmission control module 1013, an authentication management module 1015 connected with the transmission communication module 1014, a storage module 1016 connected with the authentication management module 1015, and the like. It is to be understood that the power transmitting module 1012 may be specifically a power transmitting coil (or simply a transmitting coil), and is not limited herein.

In some possible embodiments, the emission conversion module 1011 can be connected to a power source for obtaining energy from the power source and converting ac or dc power provided by the power source into high frequency ac power. Here, when the current input by the power supply is ac, the transmitting and transforming module 1011 may be composed of a power factor correction unit (not shown in fig. 2), an inverter unit (or inverter circuit, not shown in fig. 2) and a transmitting terminal compensation network (not shown in fig. 2). When the current input by the power supply is dc, the transmission conversion module 1011 is composed of an inverter unit (not shown in fig. 2) and a transmission end compensation network (not shown in fig. 2). The power factor correction unit can ensure that the input current phase of the wireless charging system is consistent with the voltage phase of the power grid, reduce the harmonic content of the system and improve the power factor value, so that the pollution of the wireless charging system to the power grid is reduced and the reliability is improved. The power factor correction unit can also increase or decrease the output voltage of the power factor correction unit according to the requirement of the later stage circuit in the actual application scene, and when the variable range of the output voltage of the power factor correction unit does not meet the requirement, the transmission conversion module 1011 can also be added with a direct current conversion unit for adjusting the voltage output to the later stage circuit so that the variable range of the voltage output to the later stage circuit meets the requirement of the actual application scene. The inversion unit can convert the voltage output by the power factor correction unit into high-frequency alternating-current voltage, and the high-frequency alternating-current voltage acts on the power transmitting module through the transmitting terminal compensation network, so that the transmitting efficiency and the transmission distance of the power transmitting module can be greatly improved. It should be noted that the power source may be a power source inside the wireless charging transmitting device 1010, or an external power source externally connected to the wireless charging transmitting device 1010, which may be determined according to an actual application scenario, and is not limited herein.

And the power transmitting module 1012 is used for transmitting the high-frequency alternating current provided by the transmitting and converting module 1011 in a magnetic field mode.

And the transmission control module 1013 is configured to control the voltage, the current, and the frequency conversion parameter of the transmission conversion module 1011, and control the voltage and the current of the high-frequency alternating current in the power transmission module 1012 according to the transmission power requirement of the wireless charging in an actual application scenario.

The transmitting and communicating module 1014 is configured to perform wireless communication between the wireless charging transmitting device 1010 and the wireless charging receiving device 1000, and includes communication transmission of information such as power control information, fault protection information, startup and shutdown information, and mutual authentication information. On one hand, the wireless charging transmitting device 1010 may receive the attribute information, the charging request and the mutual authentication information of the electric vehicle, which are sent by the wireless charging receiving device 1000; on the other hand, the wireless charging transmitting device 1010 may also transmit wireless charging transmitting control information, mutual authentication information, wireless charging history data information, and the like to the wireless charging receiving device 1000. Specifically, the above-mentioned wIreless communication mode may include, but is not limited to, any one or more of bluetooth (bluetooth), wIreless broadband (WiFi), Zigbee (Zigbee), Radio Frequency Identification (RFID), long range (Lora), and Near Field Communication (NFC). Optionally, the transmitting communication module 1014 may further communicate with an intelligent terminal of an affiliated user of the electric vehicle, and the affiliated user realizes remote authentication and user information transmission through a communication function.

And the authentication management module 1015 is used for the interactive authentication and authority management between the wireless charging transmitting device 1010 and the electric vehicle in the wireless charging system.

A storage module 1016, configured to store charging process data, mutual authentication data (e.g., mutual authentication information), and rights management data (e.g., rights management information) of the wireless charging transmitting device 1010. The interactive authentication data and the rights management data may be factory settings or user settings, and may be determined according to an actual application scenario, which is not limited herein.

In some possible embodiments, the wireless charge receiving apparatus 1000 includes: a power reception module 1001, a reception conversion module 1002, a reception control module 1003 connected to both the power reception module 1001 and the reception conversion module 1002, and a reception communication module 1004 connected to the reception control module 1003. It is to be understood that the power receiving module 1001 may be specifically a power receiving coil (or simply a receiving coil), and is not limited herein. Optionally, the receiving and converting module 1002 may be connected to the energy storage module 1005, so as to use the energy received by the receiving and converting module to charge the energy storage module. The energy storage module 1005 may be connected to the energy storage management module 1006, and the energy storage management module 1006 may be connected to a vehicle driving device of the electric vehicle, for driving the electric vehicle. It should be noted that the energy storage management module 1006 and the energy storage module 1005 may be located inside the wireless charging receiving device 1000, or may be located outside the wireless charging receiving device 1000, and may be determined according to requirements of an actual application scenario, which is not limited herein.

The power receiving module 1001 is configured to receive active power and reactive power transmitted by the wireless charging transmitting apparatus 1010. Here, the power receiving module 1001 may be a power receiving coil that transfers energy by electromagnetic induction with a power transmitting coil (i.e., the power transmitting module 1012) in the wireless charging transmitting device 1010. The compensation network of the power transmitting end and the compensation of the power receiving end in the wireless charging system can be selectively combined at will, and common compensation network structure combination forms include an S-S (Series-Series) type, a P-P (Parallel-Parallel) type, an S-P (Series-Parallel) type, a P-S (Parallel-Series) type, an LCL-LCL (indicator-indicator) type, an LCL-P (indicator-indicator) type, an LCC-LCC (indicator-indicator) type and other structures.

The receiving and converting module 1002 is configured to convert the high-frequency resonant current and the high-frequency resonant voltage received by the power receiving module 1001 into a dc voltage and a dc current required for charging the energy storage module 1005. The receiving transformation module 1002 generally comprises a receiving end compensation network (not shown in fig. 2), a rectification unit (or rectification circuit, not shown in fig. 2); the rectifying unit converts the high-frequency resonant current and the high-frequency resonant voltage received by the power receiving module 1001 into a direct current voltage and a direct current, and if the voltage output by the rectifying unit cannot meet the requirement of the energy storage module, a direct current converting unit (not shown in fig. 2) is added for voltage regulation.

The receiving control module 1003 is configured to control voltage, current, and frequency conversion parameter adjustment of the receiving conversion module 1002 according to a receiving power requirement of wireless charging in an actual application scenario.

The receiving and communicating module 1004 is configured to wirelessly communicate between the wireless charging receiving device 1000 and the wireless charging transmitting device 1010, and includes communication transmission of information such as power control information, fault protection information, power on/off information, and mutual authentication information. Specifically, the role of the receiving communication module 1004 corresponds to the role of the transmitting communication module 1014 in the wireless charging transmitting device 1010, and for brevity, the detailed description thereof is omitted here.

The arrangement of the foreign matter detection device:

the application provides a wireless transmitting terminal equipment that charges, this wireless transmitting terminal equipment that charges include power transmitting device and foreign matter detection device, including power transmitting coil in this power transmitting device, this foreign matter detection device sets up in one side of the power receiving arrangement that power transmitting coil orientation is wireless to charge. Here, the power transmitter may be the wireless charging transmitter 1010 shown in fig. 2, the power transmitter coil may be the power transmitter module 1012 shown in fig. 2, the wireless charging power receiver may be the wireless charging receiver 1000 shown in fig. 2, the wireless charging receiver includes a power receiver coil (e.g., the power receiver module 1001 shown in fig. 2), and the foreign object detector may be disposed on a side of the power transmitter coil facing the power receiver coil. In other words, the foreign object detection device provided by the present application is disposed between the power transmitting device and the power receiving device of the wireless charging system. Alternatively, the foreign object detection device may be integrated in a power transmitting coil of the wireless charging system and the foreign object detection device may be disposed at a side of the power transmitting coil facing the power receiving coil. Alternatively, the foreign object detection device may be integrated in a power receiving coil of the wireless charging system and the foreign object detection device may be disposed at a side of the power receiving coil facing the power transmitting coil. The specific setting position of the foreign object detection device can be determined according to the requirements of the actual application scene, and is not limited herein.

For convenience of description, the wireless transmitting device may be exemplified by the wireless charging transmitting device 1010 shown in fig. 1, and the power receiving device may be exemplified by the wireless charging receiving device 1000 shown in fig. 1, so as to illustrate the position relationship between the foreign object detection device and the power transmitting device and the power receiving device provided in the present application. Referring to fig. 3, fig. 3 is a schematic view of an arrangement position of the foreign object detection device provided by the present application. For example, as shown in fig. 1, if the wireless charging transmitting device 1010 and the wireless charging receiving device 1000 of the wireless charging system are in a position relationship between the ground and the ground, and the energy transfer direction between the transmitting coil (not shown in fig. 1) of the wireless charging transmitting device 1010 and the receiving coil (not shown in fig. 1) of the wireless charging receiving device 1000 is a vertical direction from the ground to the ground, the foreign object detection device may be integrated in the wireless charging transmitting device 1010 and disposed on a side of the transmitting coil of the wireless charging transmitting device 1010 facing the receiving coil of the wireless charging receiving device. In other words, at this time, the foreign object detection device may be disposed above the transmission coil of the wireless charging transmission device 1010.

The circuit configurations of the wireless charging system and the foreign object detection device provided by the present application will be described below with reference to the wireless charging system shown in fig. 2. For convenience of description, in the circuit structure of the wireless charging system and the foreign object detection device provided in the present application, the power supply, the transmission conversion module 1011, and the power transmission module 1012 in the wireless charging transmitting device 1010 shown in fig. 2 will be taken as an example for the wireless transmitting device, and the power receiving module 1001 and the receiving conversion module 1002 in the wireless charging receiving device 1000 shown in fig. 2 will be taken as an example for the wireless receiving device.

Circuit structure of foreign matter detection device:

referring to fig. 4, fig. 4 is a schematic circuit structure diagram of the wireless charging system and the foreign object detection device provided in the present application. In the wireless charging system shown in fig. 4, the wireless transmitting device may include a power supply, an inverter (such as the above-mentioned inverter circuit, the inverter unit, etc.), the compensation network 1, and the transmitting coil Lp. The transmitting coil Lp may correspond to the power transmitting module 1012 in the wireless charging transmitting apparatus 1010 shown in fig. 2, and the compensation network 1 and the inverter may correspond to the transmitting conversion module 1011 in the wireless charging transmitting apparatus 1010 shown in fig. 2. The receiving coil Ls may correspond to the power receiving module 1001 in the wireless charging receiving apparatus 1000 shown in fig. 2, and the compensating network 2 and the rectifier (such as the above-mentioned rectifying circuit, rectifying unit, etc.) may correspond to the power receiving module 1001 in the wireless charging receiving apparatus 1000 shown in fig. 2. The load may be obtained by one or a combination of more than one of the energy storage module 1000, the energy storage management module 1006 and the station driving device in the wireless charging system shown in fig. 2, and may be determined according to an actual application scenario, which is not limited herein.

As shown in fig. 4, the foreign object detection apparatus provided by the present application includes a plurality of inductors, such as inductors L1, L2, … …, Ln, disposed above the transmitting coil Lp of the power transmitting apparatus, where n is an integer greater than 2. The foreign object detection apparatus further includes a plurality of switches (e.g., S1, S2, … …, Sn), a plurality of resonance capacitors (e.g., C1, C2, … …, Cn), an excitation source, and a detection control module. An inductance coil and a resonance capacitor form a resonance network (or parallel resonance network), a selector switch is connected with the resonance network in series to obtain a resonance unit, and a plurality of resonance units are connected in parallel at two ends of an excitation source. For example, the inductance coils L1, L2, … … and Ln can be respectively connected with the resonance capacitors C1, C2, … … and Cn in parallel to form n resonance networks, one parallel resonance network and one switch are connected in series to form one resonance unit, for example, the resonance unit 1, the resonance unit 2 and … … and the resonance unit n, and the n resonance units are connected in parallel to two ends of the excitation source. Referring to fig. 5, fig. 5 is a circuit schematic diagram of the foreign object detection apparatus provided in the present application. In other words, the foreign object detection apparatus provided by the present application includes an excitation source 501, a resonance module 502, and a detection control module 503, and the resonance module 502 is connected to the excitation source 501 and the detection control module 503, respectively. The resonant module 502 includes at least two resonant units (e.g., resonant unit 1, resonant unit 2, … …, and resonant unit n, n is an integer greater than 2) connected in parallel, where one resonant unit includes an inductor (e.g., inductor L1 in resonant unit 1), a first capacitor (for convenience of description, the resonant capacitor will be exemplified below, e.g., resonant capacitor C1 in resonant unit 1), and a switch (e.g., S1 in resonant unit 1), the inductor (i.e., L1) and the first capacitor (i.e., C1) of any resonant unit (e.g., resonant unit 1) are connected in parallel to obtain a resonant network, and the resonant network of any resonant unit (e.g., resonant unit 1) is connected in series with the switch (i.e., S1). The detection control module is used for determining whether foreign matters exist between the power transmitting device and the power receiving device according to the electrical parameters of each resonant network in the resonant module under the action of the excitation current.

Optionally, the switch is composed of metal-oxide-semiconductor field-effect transistors (MOSFETs) connected in series in an inverted manner, and metal foreign object detection can be performed on the areas covered by all coils connected in the switch by alternately switching the switches S1 and S2 … Sn. For example, when the changeover switch S1 is closed, metal foreign matter detection can be performed on the area covered by the connected inductor L1. As shown in fig. 6, fig. 6 is an equivalent circuit schematic diagram of the foreign object detection device provided in the present application. When the switch S1 is closed, the inductor L1 and the resonant capacitor C1 are connected in parallel to obtain the resonant network 1 (not shown in fig. 6), the excitation source may provide an excitation current for the resonant network 1, and the detection control module may acquire an electrical parameter of the resonant network 1. The inductance coil L1 and the resonance capacitor C1 form a parallel resonance network, and when resonance occurs, the inductance coil L1 and the resonance capacitor C1 satisfy the following formula (1):

where ω is a resonance angular frequency, ω is 2 pi f in relation to the resonance angular frequency ω, L1 is an inductance value of the inductor L1, and C1 is a capacitance value of the resonant capacitor C1.

In the theoretical design of a hardware circuit, the resonant frequency of a resonant network in the foreign object detection device is determined, but due to the tolerance of a device, a deviation exists between a design value and an actual value, so that in the debugging process, the inductance value of each inductance coil is measured first, and the resonant frequency of each resonant network is calculated when no metal foreign object exists. Alternatively, the resonant frequency may be detected by a frequency sweep, where the frequency sweep is obtained by changing the frequency excited by the excitation source to change the frequency within a range, and the corresponding frequency is the resonant frequency when the voltage on the resonant network is the maximum. Since the deviation of the design value from the actual value is usually not very large, the frequency sweep is usually performed around the design value of the resonance frequency, e.g. in the vicinity of the estimated resonance frequency.

Optionally, in some possible embodiments, the detection control module may include a measurement circuit and a foreign object detection controller. The measuring circuit can be used for detecting the electrical parameters of each resonant network in the resonant module of the foreign matter detection device. Optionally, the electrical parameters of the resonant networks may be voltages at two ends of the resonant network, currents flowing through the resonant network, impedances of the resonant networks, and the like, and may be determined according to actual application scenarios, which is not limited herein. The detection of the electrical parameters of each resonant network in the resonant module by the measuring circuit further includes processing procedures of signal sampling, filtering, amplifying and the like, and the detection can be specifically determined according to an actual application scenario, which is not limited herein. The measurement circuit outputs a signal proportional to the voltage across the resonant network, or the current through the resonant network, or the impedance of the resonant network. The foreign matter detection controller can be used for processing signals measured by the measuring circuit and initial signals prestored in a register of the foreign matter detection controller when no metal foreign matter exists, carrying out corresponding calculation and judging whether metal foreign matter exists in an area covered by an inductance coil of the resonance network according to a calculation result.

Referring to fig. 7, fig. 7 is another circuit schematic diagram of the foreign object detection apparatus provided in the present application.

In some possible embodiments, the excitation source (such as the excitation source 701 shown in fig. 7) in the foreign object detection apparatus includes a power source, a first switch K1, a second switch K2, a first inductor Lm, and a third capacitor Cm. The first switch K1 and the second switch K2 are connected in series and then connected in parallel to two ends of the power supply, one end of the first inductor Lm is connected with the first switch K1 and the second switch K2 respectively, the other end of the first inductor Lm is connected with the third capacitor Cm and connected with the resonance module 502 as one end of the excitation source, and the other end of the third capacitor Cm is connected with the power supply and the second switch K2 respectively and connected with the resonance module 502 as the other end of the excitation source. The power supply, the first switch K1, the second switch K2, the first inductor Lm and the third capacitor Cm form a current source generator, the current is provided at the port A, B, and AB is equivalent to an excitation source. Here, the first switch and the second switch are controllable switches, such as MOSFET transistors. In the foreign object detection apparatus shown in fig. 7, the resonance module 702 may be the same as the resonance module 502 in the foreign object detection apparatus shown in fig. 5, and the detection control module 703 may be the same as the detection control module 503 in the foreign object detection apparatus shown in fig. 5.

Referring to fig. 8, fig. 8 is another circuit schematic diagram of the foreign object detection apparatus provided in the present application.

In some possible embodiments, the excitation source (such as the excitation source 801 shown in fig. 8) in the foreign object detection apparatus may further include a fifth capacitor (such as the capacitor Cs 1). The first inductor Lm and the fifth capacitor Cs1 are connected in series and then connected to the third capacitor Cm. The fifth capacitor Cs1 may be used to adjust the inductance of the first inductance Lm. When the first inductor Lm is connected in series with the fifth capacitor Cs1, the equivalent inductance of the first inductor Lm is

Optionally, in some possible embodiments, the excitation source (such as the excitation source 801 shown in fig. 8) in the foreign object detection apparatus may further include a sixth capacitor (such as the capacitor Cs 2). One end of the sixth capacitor Cs2 is connected to the first inductor Lm and the third capacitor Cm, respectively, and the other end of the sixth capacitor Cs2 is connected to the resonant module 802 as one end of the driving source 801. The sixth capacitor Cs2 is a dc blocking capacitor, and plays a role in protecting the resonant network.

Optionally, in some possible embodiments, the excitation source (such as the excitation source 801 shown in fig. 8) in the foreign object detection apparatus may further include a fifth capacitor (such as the capacitor Cs1) and a sixth capacitor (such as the capacitor Cs2), the third capacitor Cm is connected after the first inductor Lm and the fifth capacitor Cs1 are connected in series, one end of the sixth capacitor Cs2 is connected to the fifth capacitor Cs1 and the third capacitor Cm, respectively, and the other end of the sixth capacitor Cs2, which is used as one end of the excitation source 801, is connected to the resonance module 802.

Optionally, in some possible embodiments, any resonant unit in the resonant module (such as the resonant module 802 shown in fig. 8) in the foreign object detection apparatus may further include a second capacitor (such as the capacitor Cc1 in the resonant unit 1), and any resonant unit (such as the resonant unit 1)) Is connected in series with a second capacitor (e.g. capacitor Cc1) and then in parallel with a first capacitor (e.g. capacitor C1) to obtain a resonant network (e.g. resonant network 1, not shown in fig. 8) of the resonant unit 1. Series capacitances (such as capacitances Cc1, Cc2, … … and Ccn) added on branches of each inductance coil (such as inductance coils L1, L2, … … and Ln) on each resonance network (such as the resonance unit 1, the resonance unit 2 and … …, the resonance network 1 (not shown in FIG. 8) in the resonance unit n, the resonance network 2 (not shown in FIG. 8), … … and the resonance network n (not shown in FIG. 8) can be used for adjusting the inductance of the inductance coils L1, L2, … … and Ln, and after the inductance coil L1 is connected with the capacitance Cc1 in series, the equivalent inductance of the inductance coil L1 is equal to the inductance of the inductance coil L1

In the foreign object detection apparatus shown in fig. 8, the detection control module 803 may be the same as the detection control module 503 in the foreign object detection apparatus shown in fig. 5. The capacitances Cs1 and Cs2 added to the excitation source can be added separately or simultaneously, and the adjusting capacitance of the inductor in the parallel resonant network can also be added separately, and the circuit configuration shown in fig. 8 is only one possible implementation. The Cs1 and Cs2 and the addition of the adjusting capacitor of the inductor in the parallel resonant network may be variously combined, and may be determined according to the actual application scenario, which is not exhaustive here.

Decoupling the coil assembly:

the foreign matter detection device provided by the application has the advantages that the inductance coils and the resonance capacitors in the resonance units are connected in parallel to obtain the parallel resonance networks, each parallel resonance network is connected with the corresponding change-over switch in series, and then the change-over switches of the resonance units are switched among the resonance networks of different resonance units. In other words, the metal foreign object detection can be performed on the area covered by all the connected induction coils through the alternate switching of the switches (such as the switches S1 and S2 … Sn) in different resonance units. However, when switching an accessed resonant network by a switch, different resonant networks may interfere with each other if adjacent resonant networks are not decoupled. The reasons for mutual interference caused when the accessed resonant network is switched by the switch are as follows: when any switch (such as the switch S1) is closed, the corresponding resonant network (such as the resonant network 1) connected in series with the switch S1 works in parallel resonance, while the other switched off resonant networks (such as the resonant network 2, the resonant network 3, … …, and the resonant network n) form series resonance, the inductor coil (i.e., the inductor coil L1) working in parallel resonance will induce an induced voltage on the inductor coil (i.e., the inductor coils L2, … …, and the inductor coil Ln) in series resonance, the induced voltage respectively acts on the respective resonant network of each inductor coil, and the impedance of the resonant network in series resonance is small, and the induced voltage will cause a large resonant current in the resonant network in series resonance.

In order to solve the problem of mutual interference between different resonant networks caused when a switch is switched to access the resonant network (or a parallel resonant network is switched for short), each inductance coil in the foreign matter detection device provided by the application can form a decoupling coil group, and the interference between the different resonant networks caused when the parallel resonant network is switched is avoided in a mode that each inductance coil forms the decoupling coil group. The inductance coil of any resonance unit in the foreign matter detection device provided by the application and the inductance coil of at least one other resonance unit in the foreign matter detection device form a decoupling coil group, and the mutual inductance coefficient between the inductance coils in the decoupling coil group is zero. It should be noted that the manner in which the inductance coils form the decoupling coil group provided by the present application is applicable to the foreign object detection device shown in any one of the circuit schematic diagrams of fig. 5 to 8. For convenience of description, a decoupling coil set (hereinafter, referred to as a decoupling coil set) composed of any two or more than two inductors is simply exemplified below.

The inductance coils included in the decoupling coil group provided by the application can be 8-shaped coils, and the current flow directions in two coils of the 8-shaped coils are opposite. Here, the 8-shaped coil is formed by winding the coil in the inductor coil in an 8-shaped winding manner, so that magnetic fields of two turns in the inductor coil are mutually cancelled. Referring to fig. 9, fig. 9 is a schematic diagram of a winding manner and a direction of magnetic lines of the 8-shaped coil provided by the present application. In other words, the 8-shaped coil means that the winding of the inductor coil is formed in a 8 shape. As shown in fig. 9, the 8-shaped coil includes two turns of the 8 shape, such as a turn 1 and a turn 2, wherein the current direction in the turn 1 is clockwise, and the current direction in the turn 2 is counterclockwise, that is, the current flow directions in the two turns of the 8-shaped coil are opposite. The direction of the magnetic lines of force in the two turns can be judged to be opposite from each other by the right-hand spiral rule, as shown in fig. 9, where "●" indicates the direction in which the magnetic lines of force are coming out, and "x" indicates the direction in which the magnetic lines of force are coming in. The directions of the magnetic lines of force in the two coils of the 8-shaped coil are opposite, the magnetic lines of force in the 8-shaped coil are in and out one by one, and the magnetic fields are just counteracted with each other, so that the 8-shaped coil is in a state of magnetic balance.

The shape of the inductance coil in the foreign matter detection device provided by the application can be rectangular, square, hexagonal, octagonal, circular and the like, and can be determined according to practical application scenes, and the device is not limited herein. For convenience of description, a rectangle will be exemplified below, such as the rectangle shown by the dotted line in fig. 9, and will not be described again below. A decoupling coil group comprises at least two inductance coils, and the magnetic fields of the inductance coils are mutually offset. For convenience of description, the following description will be given by taking an example in which one decoupling coil group includes two inductance coils and one decoupling coil group includes 3 inductance coils as an example.

In some possible embodiments, when two inductors are included in one set of decoupling coils, the magnetic fields of the two inductors cancel each other and are arranged in a matrix of decoupling coils in two rows or two columns. Referring to fig. 10, fig. 10 is a schematic diagram of a decoupling coil assembly provided in the present application. As shown in fig. 10, two 8-shaped coils (e.g., the 8-shaped coil (r) and the 8-shaped coil (r) may form a vertical column matrix (as shown in fig. 10 (a)), and the 8-shaped coil (r)) may also form a vertical row matrix (as shown in fig. 10 (b)), where the positions of the 8-shaped coil (r) and the 8-shaped coil (r) may be interchanged. Here, the up-down vertical may be a vertical along the y-direction of the coordinate axis, and the left-right vertical may be a vertical along the x-direction of the coordinate axis. It is understood that the two inductors may be arranged in a matrix, such that the coil planes of the two inductors are on the same plane, for example, two figure-8 coils are both laid on the same table or the same PCB. As shown in fig. 10, the figure-8 coil (r) includes two turns, i.e., a turn 11 and a turn 12, respectively, and the figure-8 coil (r) includes two turns, i.e., a turn 21 and a turn 22, respectively. Here, the mutually perpendicular of the 8-shaped coil (i) and the 8-shaped coil (ii) may be that central axes of the two 8-shaped coils are mutually perpendicular, for example, as shown in (a) of fig. 10, a central line of two loops (e.g., the loop 11 and the loop 12) in the 8-shaped coil (i) is a central axis of the 8-shaped coil (i.e., the central axis 1, which is not shown in the figure, is along a direction of a coordinate axis y), a central line of two loops (e.g., the loop 21 and the loop 22) in the 8-shaped coil (i.e., the central axis 2, which is not shown in the figure, is a central axis of the 8-shaped coil (i.e., the central axis 2 is along a direction of.

Referring to fig. 11, fig. 11 is another structural schematic diagram of the decoupling coil assembly provided in the present application. As shown in fig. 11, two inductors included in one decoupling coil group may be arranged in a decoupling coil matrix in two rows in a matrix, the two inductors in the decoupling coil matrix are perpendicular to each other, one of the inductors may be placed in a horizontal direction (for example, along the x direction of the coordinate axis), the other one of the decoupling coils may be placed in a vertical direction (for example, along the y direction of the coordinate axis), and the two 8-shaped coils placed in the horizontal direction and the vertical direction are arranged in a longitudinal direction. In the decoupling coil set shown in fig. 11 (a), (b), (c) and (d), two turns in the upper 8-shaped coil are horizontally oriented (the line connecting the centers of the two turns is along the y direction of the coordinate axis), two turns in the lower 8-shaped coil are vertically oriented (the line connecting the centers of the two turns is along the x direction of the coordinate axis), and the inward "cross (i.e., x)" and the outward "point (i.e., ●)" of the magnetic force lines are interchangeable (i.e., the direction of current flow in the 8-shaped coil can be changed), without affecting the decoupling of the two coils. Similarly, in the decoupling coil set shown in fig. 11 (e), (f), (g) and (h), two loops of 8-shaped coils placed in the vertical direction can be placed on the upper side, two loops of 8-shaped coils placed in the horizontal direction can be placed on the lower side, and the two 8-shaped coils are also decoupled.

Referring to fig. 12, fig. 12 is another structural schematic diagram of the decoupling coil assembly provided herein. As shown in fig. 12, the two inductors included in one decoupling coil set may be arranged in a matrix as a two-row decoupling coil matrix in which the two inductors are perpendicular to each other. Wherein. The two circles of 8-shaped coils arranged in the horizontal direction and the two circles of 8-shaped coils arranged in the vertical direction are transversely arranged. In the decoupling coil set shown in fig. 12 (a), (b), (c) and (d), two turns of the left figure-8 coil are horizontally disposed, two turns of the right figure-8 coil are vertically disposed, and inward "crosses" and outward "points" of the magnetic lines are interchangeable (i.e., the direction of current in the figure-8 coil can be changed), which does not affect the decoupling of the two coils. Similarly, the position interchange of the left figure-8 coil and the right figure-8 coil is also decoupled from each other, and no further illustration is given here.

In some possible embodiments, when there are more than one decoupling coil set formed by the inductance coils of each resonance unit in the resonance module (i.e., each inductance coil in the resonance module forms at least two decoupling coil sets), the at least two decoupling coil sets are arranged in a matrix as a coil matrix with a plurality of rows or columns, and the magnetic fields of two inductance coils in adjacent rows or adjacent columns in the coil matrix are mutually cancelled. Referring to fig. 13, fig. 13 is another structural schematic diagram of the decoupling coil assembly provided by the present application. As shown in (a) and (b) of fig. 13, when a plurality of sets of decoupling coils (assuming 2 sets of decoupling coils) form a coil matrix (a coil matrix with 2 rows and 2 columns) to cover all positions above the transmitting coil of the power transmitting device, the principle of the same decoupling of adjacent coil sets is followed, as shown in (a) and (b) of fig. 13, no matter how the direction of current in the 8-shaped coils is changed, the 8-shaped coils are placed up, down, left, right, and the like, the 8-shaped coils in the same decoupling coil set are decoupled from each other, and two 8-shaped coils in the same position in the adjacent decoupling coil sets are decoupled from each other. That is, (a) and (b) in fig. 13, 2 decoupling coil sets are arranged in a matrix as a 2-row 2-column coil matrix and the magnetic fields of two inductive coils in adjacent rows and adjacent columns in the coil matrix cancel each other out. When the resonant network is switched, no voltage is induced in the adjacent inductor coil by any inductor coil in the coil matrix.

In some possible embodiments, when the number of the decoupling coil sets formed by the inductance coils of each resonance unit in the resonance module is more than one (i.e., each inductance coil in the resonance module forms at least two decoupling coil sets), the at least two decoupling coil sets may also be stacked to form a coil matrix of at least two layers, and the magnetic fields of two adjacent inductance coils at the same position of the upper layer and the lower layer in the coil matrix are mutually cancelled. Referring to fig. 14, fig. 14 is another structural schematic diagram of the decoupling coil assembly provided by the present application. As shown in fig. 14, it is assumed that the resonant module includes 4 decoupling coil sets, and the 4 decoupling coil sets may form a two-layer coil matrix, where (a) in fig. 14 is an upper decoupling coil matrix, and (b) in fig. 14 is a lower decoupling coil matrix, and the upper and lower layers are both 2 rows and 2 columns of decoupling coil matrices. When the decoupling coil matrixes of the upper layer and the lower layer are stacked together, a single-layer detection blind area can be eliminated. Optionally, when the decoupling coil matrixes of the upper layer and the lower layer are stacked together, the decoupling coil matrixes of the upper layer and the lower layer can be staggered by a certain distance in the stacking process, so that a detection blind area when the coil matrixes are single layers is eliminated. In other words, the inductor coil of the upper layer in the coil matrix composed of a plurality of decoupling coil sets overlaps with the inductor coil of the lower layer; or the inductor coil of the upper layer is partially overlapped with the inductor coil of the lower layer.

In some possible embodiments, taking fig. 14 (a) as an example, the detection blind area of the single-layer decoupling coil matrix is located at the middle position of the figure-8 coil (i.e., the position in the middle of two turns of the figure-8 coil), and at the position of the boundary of different figure-8 coils, as shown by the dotted line in fig. 15, and fig. 15 is another structural schematic diagram of the decoupling coil set provided by the present application. And eliminating the detection blind areas, and covering the positions of the corresponding detection blind areas in the decoupling coil matrix of the layer by using the decoupling coil matrix of the other layer. Optionally, in order to better eliminate the detection blind area, the decoupling coil matrix on the upper layer and the decoupling coil matrix on the lower layer may be staggered by a certain distance when stacked, that is, the inductor coils in the decoupling coil matrix on the upper layer are partially overlapped with the inductor coils in the decoupling coil matrix on the lower layer. Alternatively, the two decoupling coil matrixes may be staggered by a quarter of the distance of the 8-shaped coil in the up-down-left-right direction, see fig. 16, and fig. 16 is another structural schematic diagram of the decoupling coil set provided by the present application. It can be understood that the distance of the upper decoupling coil matrix and the lower decoupling coil matrix staggered in the up-down, left-right direction may also be a distance of other dimensions, and may be determined specifically according to an actual application scenario, which is not limited herein. Here, the resonant network of the upper and lower stacked structures may perform detection of the metal foreign object in the same manner as the single-layer resonant network, and the resonant frequencies may be the same or different, and may be determined specifically according to an actual application scenario, which is not limited herein.

Alternatively, in some possible embodiments, when three inductors are included in one decoupling coil set, the three inductors may include one first inductor and two second inductors. Here, the first inductor winding may have a size larger than that of the second inductor winding. The two second inductance coils are arranged into an inductance coil group, the directions of the magnetic fields of the two second inductance coils in the inductance coil group are the same, the magnetic fields of the inductance coil group and the magnetic fields of the first inductance coils are mutually offset, and the two second inductance coils are arranged into a decoupling coil matrix in two rows or two columns in a matrix manner. Here, when the inductor winding is rectangular, the length of the second inductor winding may be the same as the length of the first inductor winding, and the width of the second inductor winding is smaller than the width of the first inductor winding. The two second inductance coils are arranged in parallel to form an inductance coil group, the magnetic field directions of the two second inductance coils in the inductance coil group are the same, the length of the inductance coil group can be the same as that of the first inductance coil, and the width of the inductance coil group is the same as that of the first inductance coil.

Referring to fig. 17, fig. 17 is another structural schematic diagram of the decoupling coil assembly provided by the present application. As shown in (a), (b), (c), (d), (e) and (f) of fig. 17, the decoupling coil set is composed of one large figure-8 coil (assumed as the first inductance coil) and two small figure-8 coils (assumed as the second inductance coil), wherein the two small figure-8 coils constitute one inductance coil set, and the magnetic field directions of the two small figure-8 coils in the inductance coil set are the same. Here, two small figure-8 coils can be wound from the same wire to form two figure-8 coils, and the magnetic field directions in the two figure-8 coils are the same. In other words, two 8-shaped coils included in one inductance coil group are wound by the same wire, and the small two 8-shaped coils and the large 8-shaped coil form a decoupling coil group all the time as a whole. As shown in fig. 17 (a), two turns of the large figure-8 coil are vertically disposed (two turns of the large figure-8 coil are disposed along the direction of the coordinate axis y, when the central connecting line of the two turns is parallel to the coordinate axis x), and two turns of each of the small figure-8 coil are horizontally disposed (i.e., two turns of the small figure-8 coil are disposed along the direction of the coordinate axis x, when the central connecting line of the two turns of the small figure-8 coil is parallel to the coordinate axis y). The small two figure-8 coils form an inductance coil group. As shown in (a), (b), (c), (d) of fig. 17, the large figure-8 coil and the inductance coil group composed of two small figure-8 coils may be in a vertical structure arranged up and down (in this case, the large figure-8 coil and the inductance coil group are arranged in a matrix as a decoupling coil matrix of 2 columns), and as shown in (e) and (f) of fig. 17, the large figure-8 coil and the inductance coil group composed of two small figure-8 coils may also be in a horizontal structure arranged left and right (in this case, the large figure-8 coil and the inductance coil group are arranged in a matrix as a decoupling coil matrix of 2 rows). The upper, lower, left and right structures in each decoupling coil matrix are interchangeable, in other words, the upper, lower, left and right inductors in each decoupling coil matrix are interchangeable, and the current directions in the inductors are also changeable, because the combination forms are various, which is not exhaustive here. It can be understood that the composition principle of each inductor in any decoupling coil matrix is that the magnetic field generated by any 8-shaped coil to the adjacent inductor is cancelled, so that interference to other inductors due to electromagnetic induction is avoided when any resonant network is switched, and the combination mode of the inductors in each decoupling coil matrix can be determined according to the requirements of practical application scenes, without limitation.

Referring to fig. 18, fig. 18 is another structural schematic diagram of the decoupling coil assembly provided by the present application. Similarly, when a plurality of decoupling coil groups form a decoupling coil matrix covering all positions above the transmitting coil, the principle that adjacent decoupling coil groups are decoupled similarly is followed, as shown in (a) and (b) in fig. 18, no matter how the direction of current in the 8-shaped coils is changed, the 8-shaped coils are placed up, down, left and right, the 8-shaped coils in the same decoupling coil group are decoupled from each other, and two 8-shaped coils at the same position in the adjacent decoupling coil groups are decoupled from each other. When the resonant network is switched, no voltage is induced in the adjacent inductor coil by any inductor coil in the coil matrix. When the plurality of decoupling coil sets are arranged in a stacked manner as a coil matrix with at least two layers, the magnetic fields of two adjacent inductance coils at the same position of the upper layer and the lower layer in the coil matrix are mutually offset. Specifically, reference may be made to the corresponding implementation manner in the structural schematic diagram of the decoupling coil set described in fig. 14, which is not described herein again. Similarly, when the decoupling coil matrixes of the upper layer and the lower layer are stacked together, the decoupling coil matrixes of the upper layer and the lower layer can be staggered by a certain distance when being stacked, so that a detection blind area when the coil matrixes are single layers is eliminated. Fig. 19 is another schematic structural diagram of the decoupling coil assembly provided by the present application, as shown in fig. 19. Specifically, reference may be made to the corresponding implementation manner in the structural schematic diagram of the decoupling coil set described in fig. 16, which is not described herein again.

It should be noted that the structural diagrams of the decoupling coil sets shown in fig. 10 to fig. 19 are only the structure of a simple decoupling coil set, in practical applications, the area of the transmitting coil of the power transmitting device is generally relatively large, many sets of inductance coils need to be arranged in the foreign object detection device, and the inductance coils of the foreign object detection device cover all the surfaces of the transmitting coil of the power transmitting device, as shown in fig. 20, and fig. 20 is a schematic configuration diagram of the inductance coils in the foreign object detection device.

The foreign matter detection method can be applied to the wireless charging system before the wireless charging system charges the electric automobile, and can also be applied to the wireless charging system in the process of charging the electric automobile, and the method is used for detecting the metal foreign matters between the wireless charging transmitting device and the wireless charging receiving device. The foreign object detection method provided by the present application may be performed based on any circuit structure of the foreign object detection device shown in fig. 5 to 8 and based on any structure of the decoupling coil assembly shown in fig. 10 to 19, and may be specifically determined according to requirements of an actual application scenario, which is not limited herein. For convenience of description, the foreign object detection method provided by the present application will be described below with reference to fig. 21 to 22 by taking the foreign object detection device shown in fig. 5 as an example.

The foreign matter detection method based on the foreign matter detection device provided by the application comprises the following steps:

in some possible embodiments, when detecting a metallic foreign object between a power transmitting device and a power receiving device of a wireless charging system by using a foreign object detection device, the metallic foreign object detection may be performed on an area (an area between the power transmitting device and the power receiving device) covered by all the connected inductive coils by alternately switching switches (such as the switches S1 and S2 … Sn) in different resonant units of the foreign object detection device. Since the detection method for detecting metal foreign objects based on all the inductance coils in the foreign object detection device is the same, the foreign object detection method provided by itself will be described below by taking one inductance coil (such as the inductance coil L1) as an example, and will not be described by way of alternate switching. In other words, the following procedure of detecting foreign objects is performed for one inductor (e.g., inductor L1), the inductors in the foreign object detection apparatus have many sets (e.g., n sets of inductors L1, L2, … …, Ln), and all inductors are traversed by switching alternately for the other inductors in the same manner. It can be understood that when the switch S1 is closed in the foreign object detection apparatus, the inductor L1 and the capacitor C1 form a parallel resonant network (e.g., resonant network 1), the switches S2, … …, and Sn are opened, and the inductors L2, … …, and Ln form a series resonance with the capacitors C2, … …, and Cn, respectively. Since the following foreign object detection process is performed on the inductor L1, the resonant network described in the following process is exemplified by the resonant network 1.

Referring to fig. 21, fig. 21 is a schematic view of an embodiment of a foreign object detection method provided in the present application. The foreign matter detection method based on the foreign matter detection device provided by the application can comprise the following steps:

s210, determining the working resonant frequency f1 of the resonant network when no metal foreign matter exists.

In some possible embodiments, in the case where the area covered by the inductor coil 1, which is a part of the area of the transmitting coil of the power transmitting apparatus, is free of metallic foreign objects, a frequency sweep is performed around the design value of the resonant frequency of the resonant network (i.e., the resonant network 1), and the operating resonant frequency f1 of the resonant network 1 (i.e., the actual operating resonant frequency of the resonant network 1) at that time is determined.

S211, measuring the voltage Uwo1 at two ends of the resonant network under the excitation of current with the working resonant frequency f1 when no metal foreign matter exists.

In some possible embodiments, the excitation source emits a current excitation with an operating resonant frequency f1 in the case that the area covered by the inductor coil 1 is free of metallic foreign objects. Under the excitation of the current from the excitation source, the measurement circuit of the detection control module detects the voltage Uwo1 across the resonant network 1 in the foreign object detection device and stores the actual operating resonant frequency f1 of the resonant network 1 and the voltage Uwo1 across the resonant network 1 in the register of the foreign object detection controller of the detection control module.

And S212, determining the voltage Uw1 at two ends of the resonant network under the excitation of the current with the working resonant frequency f1 when the metal foreign matter exists.

In some possible embodiments, the excitation source emits a current excitation with an operating resonant frequency f1 during the detection of the metal foreign object. Under the excitation of the current from the excitation source, the measuring circuit detects the voltage Uw1 across the resonant network 1 and stores the actual operating resonant frequency f1 of the resonant network 1 and the voltage Uw1 across the resonant network 1 in the register of the foreign object detection controller.

And S213, determining whether metal foreign matters exist according to the change of the voltage at two ends of the resonant network.

In some possible embodiments, in the foreign object detection controller, when the foreign object detection controller is relatively free of metal foreign objects, the voltage difference Δ U1 between the voltage Uwo1 across the resonant network 1 when excited by the current with the operating resonant frequency f1 from the excitation source and the voltage Uw1 across the resonant network 1 when excited by the current with the operating resonant frequency f1 from the excitation source is detected, where Δ U1 is Uwo1-Uw 1.

In the foreign object detection controller, the voltage difference Δ U1 is compared with a preset voltage difference threshold Δ Uset1 stored in the foreign object detection controller. If the voltage difference Δ U1 is greater than the preset voltage difference threshold Δ Uset1, it is determined that the region covered by the inductor L1 has metal foreign objects. If the voltage difference Δ U1 is less than or equal to the preset voltage difference threshold Δ Uset1, it is determined that the area covered by the inductor L1 is free of metallic foreign objects.

The implementation manners provided in steps S210 to S213 may detect whether there is a metal foreign object in the area covered by any inductor, and the metal foreign object detection may be performed on the areas covered by all the connected inductors (i.e., all the areas of the transmitter coil) by alternately switching the switches (e.g., the switches S1, S2 … Sn), so as to determine whether there is a metal foreign object between the power transmitter and the power receiver.

In the foreign matter detection device that this application provided, because mutual decoupling zero between each inductance coils, the voltage stress on the change over switch is showing and is reducing when resonant network switches over to effectively protected change over switch can not overvoltage damage, improved foreign matter detection device's circuit stability, the security that the foreign matter detected is higher, thereby improved and carried out the stability that the foreign matter detected based on this foreign matter detection device, the suitability is strong. The foreign matter detection device judges whether metal foreign matters exist in the area covered by the inductance coil of the resonant network or not through detecting the voltage at the two ends of the resonant network, and the foreign matter detection device is simple to operate and high in applicability.

A second foreign object detection method based on the foreign object detection apparatus provided by the present application:

in the second foreign object detection method provided by the present application, the foreign object detection apparatus may detect the impedance of the resonant network through a measurement circuit in the detection control module. In case the excitation source is a current source, the voltage U across the resonant network is related to the impedance Z by U-I x Z, where I is the current provided by the excitation source. The most direct method is to detect the voltage at two ends of the resonant network and judge whether the area covered by the inductance coil of the resonant network has the metal foreign matter through the voltage. However, when the current of the excitation source is unstable and cannot be completely fixed at a certain fixed value, when the foreign object detection device detects a metal foreign object, the voltage at the two ends of the resonant network may be caused by the metal foreign object or the current of the excitation source, and therefore, in this case, the voltage at the two ends of the resonant network is used to determine whether there is a metal foreign object in the area covered by the inductance coil, which is prone to be misjudged. Therefore, the change of the impedance is obtained through the voltage at the two ends of the resonance network and the current flowing through the resonance network, the accuracy rate of judging whether the metal foreign matters exist in the area covered by the inductance coil through the change of the impedance is higher, and the applicability is stronger.

In the second method, the difference between the foreign object detection process and the foreign object detection process in the first method is that only the voltages at two ends of the resonant network are detected in the first method, and whether the metal foreign object exists in the area covered by the inductance coil of the resonant network is judged by comparing the voltage difference between the two ends of the resonant network detected when no metal foreign object exists and no metal foreign object exists with a preset voltage difference threshold. And the second method for judging whether the metal foreign matter exists is to detect the voltage at two ends of the resonance network and the current flowing through the resonance network, calculate the impedance change of the resonance network according to the voltage at two ends of the resonance network and the current flowing through the resonance network, and then determine whether the metal foreign matter exists or not by comparing the impedance difference at two ends of the resonance network when no metal foreign matter and metal foreign matter are detected with a preset impedance difference threshold value.

Referring to fig. 22, fig. 22 is a schematic diagram of another embodiment of the foreign object detection method provided in the present application. The foreign matter detection method based on the foreign matter detection device provided by the application can comprise the following steps:

and S220, determining the working resonant frequency f2 of the resonant network when no metal foreign matter exists.

In some possible embodiments, in the absence of metallic foreign bodies in the area covered by the inductor 1, a frequency sweep is performed around the design value of the resonant frequency of the resonant network 1, and the actual operating resonant frequency f2 of the resonant network 1 is determined.

S221, measuring a voltage Uwo2 across the resonant network and a current Iwo2 flowing through the resonant network under current excitation at a power resonant frequency f2 when no metallic foreign object is present.

In some possible embodiments, the excitation source emits a current excitation with an operating resonant frequency f2 in the case that the area covered by the inductor coil 1 is free of metallic foreign objects. Under excitation by a current from the excitation source, the measurement circuit detects a voltage Uwo2 across the resonant network 1 and a current Iwo2 flowing through the resonant network 1. The impedance Zwo2 of the resonant network 1 at this time is calculated from the voltage Uwo2 across the resonant network 1 and the current Iwo2 flowing through the resonant network 1, and the operating resonant frequency f2 and the impedance Zwo2 are stored in registers in the foreign object detection controller.

S222, measuring the voltage Uw2 at two ends of the resonant network and the current Iw2 flowing through the resonant network under the current excitation of the power resonant frequency f2 when the metal foreign matter exists.

In some possible embodiments, the excitation source emits a current excitation with an operating resonant frequency f2 during metal foreign object detection. Under the excitation of the current emitted by the excitation source, the measurement circuit detects the voltage Uw2 across the resonant network 1 and the current Iw2 flowing through the resonant network 1. The impedance Zw2 of the resonant network 1 at this time is calculated from the voltage Uw2 across the resonant network 1 and the current Iw2 flowing through the resonant network 1, and the operating resonant frequency f2 and the impedance Zw2 are stored in a register in the foreign object detection controller.

And S223, determining whether metal foreign matters exist according to the change of the impedance of the resonant network.

In some possible embodiments, in the foreign object detection controller, when the foreign object detection controller is compared with the case of no metal foreign object, the difference Δ Z2 between the impedance Zwo2 of the resonant network 1 when excited by a current with the operating resonant frequency f2 emitted by the excitation source and the impedance Zw2 of the resonant network 1 when excited by a current with the operating resonant frequency f2 emitted by the excitation source when detecting the metal foreign object is Δ Z2 — Zwo2-Zw 2.

In the foreign object detection controller, the impedance difference Δ Z2 is compared with a preset impedance difference threshold Zset2 stored in the abnormality detection controller. If the impedance difference Δ Z2 is greater than Zset2, it may be determined that the area covered by the inductor L1 has metallic foreign substances. If the impedance difference Δ Z2 is less than or equal to Zset2, it may be determined that the area covered by the inductor L1 is free of metallic foreign matter.

In the foreign matter detection device that this application provided, because mutual decoupling zero between each inductance coils, the voltage stress on the change over switch is showing and is reducing when resonant network switches over to effectively protected change over switch can not overvoltage damage, improved foreign matter detection device's circuit stability, the security that the foreign matter detected is higher, thereby improved and carried out the stability that the foreign matter detected based on this foreign matter detection device, the suitability is strong. The foreign matter detection device can also obtain the change of impedance through the voltage at two ends of the resonance network and the current flowing through the resonance network, and the accuracy rate of judging whether the area covered by the inductance coil has the metal foreign matter or not through the change of the impedance is higher, and the flexibility is high.

Claims

1. A foreign matter detection device is characterized in that the foreign matter detection device is arranged between a power transmitting device and a power receiving device of a wireless charging system, the foreign matter detection device comprises an excitation source, a resonance module and a detection control module, and the resonance module is respectively connected with the excitation source and the detection control module;

the resonance module comprises at least two resonance units which are connected in parallel, one resonance unit comprises an inductance coil, a first capacitor and a change-over switch, the inductance coil of any resonance unit is connected with the first capacitor in parallel to obtain a resonance network, and the resonance network of any resonance unit is connected with the change-over switch in series; the inductance coil of any resonance unit and the inductance coil of at least one other resonance unit of the at least two resonance units form a decoupling coil group, and the mutual inductance coefficient between the inductance coils in the decoupling coil group is zero;

the excitation source is used for providing excitation current for the resonance module;

and the detection control module is used for determining whether foreign matters exist between the power transmitting device and the power receiving device according to the electrical parameters of each resonant network in the resonant module under the action of the excitation current.

2. The foreign object detection device according to claim 1, wherein the inductance coil of any one of the resonance units is a figure 8 coil, and current flows in opposite directions in two turns of the figure 8 coil.

3. The foreign object detection device according to claim 2, wherein the decoupling coil group includes two inductance coils whose magnetic fields cancel each other and are arranged in a matrix of the decoupling coils in two rows or two columns.

4. The foreign object detection device of claim 2, wherein the set of decoupling coils includes a first inductor coil and two second inductor coils; the two second inductance coils are arranged into an inductance coil group, and the magnetic field directions of the two second inductance coils in the inductance coil group are the same;

the magnetic fields of the inductance coil groups and the magnetic field of the first inductance coil are mutually offset and are arranged in a decoupling coil matrix of two rows or two columns in a matrix manner.

5. The foreign object detection device according to claim 3 or 4, wherein the induction coils of each of the resonance units constitute at least two decoupling coil groups;

the at least two decoupling coil groups are arranged in a matrix in a multi-row and/or multi-column coil matrix, and the magnetic fields of two inductance coils in adjacent rows and/or adjacent columns in the coil matrix are mutually counteracted.

6. The foreign object detection device according to claim 3 or 4, wherein the induction coils of each of the resonance units constitute at least two decoupling coil groups;

the at least two decoupling coil sets are arranged in a stacked mode to form at least two layers of coil matrixes, and magnetic fields of two adjacent inductance coils at the same positions of an upper layer and a lower layer in the coil matrixes are mutually offset.

7. The foreign object detection device according to claim 6, wherein an upper layer inductance coil of the coil matrix overlaps with a lower layer inductance coil; or

The upper layer of inductance coils and the lower layer of inductance coils of the coil matrix are partially overlapped.

8. The foreign object detection apparatus according to claims 1 to 7, wherein the excitation source includes a power source, a first switch, a second switch, a first inductance, and a third capacitance;

the first switch and the second switch are connected in series and then connected in parallel at two ends of the power supply, one end of the first inductor is connected with the first switch and the second switch respectively, the other end of the first inductor is connected with the third capacitor and serves as one end of the excitation source to be connected with the resonance module, and the other end of the third capacitor is connected with the power supply and the second switch respectively and serves as the other end of the excitation source to be connected with the resonance module.

9. The apparatus according to claim 8, wherein the resonant unit further comprises a second capacitor, and the inductor of the resonant unit is connected in series with the second capacitor and then connected in parallel with the first capacitor to obtain a resonant network of the resonant unit.

10. The foreign object detection device according to claim 8 or 9, wherein the excitation source further includes a fifth capacitor, and the first inductor and the fifth capacitor are connected in series and then connected to the third capacitor.

11. The foreign object detection device according to claim 8 or 9, wherein the excitation source further includes a sixth capacitor, one end of the sixth capacitor is connected to the first inductor and the third capacitor, respectively, and the other end of the sixth capacitor is connected to the resonance module as one end of the excitation source.

12. The foreign object detection device according to claim 8 or 9, wherein the excitation source further includes a fifth capacitor and a sixth capacitor, the third capacitor is connected to the first inductor and the fifth capacitor after being connected in series, one end of the sixth capacitor is connected to the fifth capacitor and the third capacitor, respectively, and the other end of the sixth capacitor, which is used as one end of the excitation source, is connected to the resonance module.

13. A wireless charging transmitting terminal device, characterized in that the wireless charging transmitting terminal device comprises a power transmitting device and a foreign object detection device according to any one of claims 1 to 12;

the power transmitting device comprises a power transmitting coil, and the foreign matter detection device is arranged on one side of the power transmitting coil, which faces the wireless charging power receiving device.