A single-layer array sensing coil type foreign object detection system applied to magnetic coupling resonant wireless power transmission and a blind elimination method thereof

Abstract

The application discloses a single-layer array sensing coil type foreign matter detection system applied to magnetic coupling resonant wireless electric energy transmission and a blind area elimination method thereof. The detection system comprises a transmitting end and a receiving end. The transmitting end comprises a foreign matter detection single-layer array sensing coil, a transmitting coil, a transmitting end magnetic shielding layer and a transmitting end magnetic core. The receiving end comprises a receiving coil, a receiving end magnetic shielding layer and a receiving end magnetic core. The foreign matter detection single-layer array sensing coil is composed of a plurality of small-size sensing units. The plurality of sensing units are uniformly and densely distributed and completely cover the whole detection area without any spare space, so that the direct blind area is eliminated. In the working time of the foreign matter detection system, each array type sensing unit presents dynamic working and stopping according to a certain frequency and rule. When a certain foreign matter falls in the indirect blind area of a certain specific anti-series connection sensing unit, other anti-series connection sensing units can effectively detect the foreign matter, so that the indirect blind area is eliminated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wireless power transmission foreign object detection, and particularly relates to a single-layer array sensing coil type foreign object detection system applied to magnetic coupling resonance wireless power transmission and a detection method thereof. BACKGROUND

[0002] Wireless power transmission technology breaks through the constraints of cables, does not require electrical connection, has no exposed interface, has no problems such as contact spark and wear and aging, has strong adaptability to bad weather or environment such as rain and snow, and an energy emission device almost does not occupy ground space, has less land resources and low maintenance cost. The technology not only can promote the alleviation of the endurance problem of electric vehicles and the strengthening of the interaction ability of vehicles and power grids, but also has been widely concerned by the academic and industrial circles at home and abroad in the application fields of consumer electronics, unmanned aerial vehicles, robots and the like.

[0003] A foreign object is any object between the transmitting end and the receiving end of a wireless power transmission system that does not belong to the system itself. Among many kinds of foreign objects, metal foreign objects and biological foreign objects can have serious adverse effects on the transmission power, efficiency and safety of the system. Foreign object detection technology is an indispensable auxiliary function to ensure the safe and stable operation of a magnetic coupling resonance type wireless power transmission system. The method of using a sensing coil for foreign object detection has become the main technology for realizing the foreign object detection function due to its low cost and easy integration with a wireless power transmission system. At present, in order to improve the detection precision and sensitivity, the foreign object detection method based on a sensing coil usually adopts an array type sensing coil and a reverse series connection mode of two sensing units to offset the interference of the energy transmission magnetic field on detection and further increase the sensing coil's perception ability to foreign objects. However, when a foreign object with uniform texture (such as a coin or other regular-shaped metal sheet) happens to cover the same area of the two sensing units in reverse series connection (such as Figure 1: foreign object is symmetrical about plane β geometry, the detection unit is also symmetrical about plane β geometry, and the foreign object is directly above the detection unit, or in the case of the electromagnetic influence of the foreign object on the two anti-serial sensing units cancels out, this detection method will fail due to decoupling between the coil and the foreign object, that is, this method will naturally cause a detection blind area, which is called an indirect blind area, the size of the indirect blind area is related to the structure of the sensing unit and the structure and properties of the foreign object, so the time and space of the occurrence of the indirect blind area have a certain randomness, and therefore its influence on the safety of the system is bad and significant, and engineering applications absolutely cannot allow such a situation to occur. In order to solve the above problems, the engineering usually adopts the technology of double-layer sensing coil cooperative work, specifically, the double-layer coil is arranged by parallel misplacement and overlapping to stagger the blind area points of the two layers of sensing coils, so that when one layer of sensing coil triggers the indirect blind area, the other layer of sensing coil can normally identify the foreign object, although the method is effective, but it will significantly increase the cost and complexity of the system, and will sacrifice the valuable energy transmission distance of the wireless power transmission system. SUMMARY

[0004] In order to solve the problems in the prior art, the purpose of the present application is to provide a single-layer array sensing coil type foreign object detection system applied to magnetic coupling resonant wireless power transmission and a blind area elimination method thereof.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A single-layer array sensing coil type foreign object detection system applied to magnetic coupling resonant wireless power transmission, the detection system comprising a transmitting end and a receiving end, the transmitting end comprising a foreign object detection single-layer array sensing coil, a transmitting coil, a transmitting end magnetic shielding layer and a transmitting end magnetic core, the receiving end comprising a receiving coil, a receiving end magnetic shielding layer and a receiving end magnetic core; the foreign object detection single-layer array sensing coil is composed of a plurality of small-size sensing units, the plurality of sensing units are uniformly and densely distributed and completely cover the entire detection area without any spare space, so as to eliminate the direct blind area of foreign object detection; the overall size of the foreign object detection single-layer array sensing coil is equal to or slightly larger than the effective area of the energy transmitting plane.

[0007] Further, the receiving end and the transmitting end are arranged opposite to each other, the receiving end magnetic shielding layer is laid on the upper end of the receiving end magnetic core, the receiving coil is laid under the receiving end magnetic core, the receiving coil and the foreign object detection single-layer array sensing coil are arranged opposite to each other, the foreign object detection single-layer array sensing coil is closely laid above the transmitting coil, and the transmitting end magnetic core and the transmitting end magnetic shielding layer are sequentially laid under the transmitting coil.

[0008] Further, the foreign object detection single-layer array sensing coil is printed by a PCB process.

[0009] Further, the sensing unit is a planar spiral coil, and the outer contour of the planar spiral coil is a triangle, a quadrilateral, a pentagon, a hexagon, or other various shapes suitable for close arrangement without gaps.

[0010] Further, each of the plurality of sensing units contains a resonant capacitor matched with the foreign object detection sensing unit, and the resonant capacitor is arranged outside the wireless charging energy coupling area by a PCB layout.

[0011] Further, the output end of each of the plurality of sensing units is connected to a switch switching module, and the switch switching module is used to realize reverse connection of different sensing units, and can ensure that any two sensing units are connected in reverse connection with an external alternating excitation source u and a current limiting protection resistor in series to realize active detection and ensure safe operation of detection.

[0012] Further, the frequency of the external alternating excitation source u is consistent with the intrinsic frequency of the reverse connection sensing unit.

[0013] Further, a blind elimination method for magnetic coupling resonant wireless power transmission using the above detection system for single-layer array sensing coil foreign object detection, comprising the following steps:

[0014] (1) Set the detection accuracy as δu, and ideally δu is set to 0, but considering the influence of the energy transmission system on the foreign object detection system and environmental noise, δu is reasonably set according to the actual application scene;

[0015] (2) Set the integer variable as q=2;

[0016] (3) In the standby state of the wireless power transmission system, continuously monitor whether the system receives a charging instruction;

[0017] (4) If a charging instruction is received, charging starts, and the foreign object detection system starts to work at the same time;

[0018] (5) In the switch switching module corresponding to each row of sensing units, the switch connecting the external alternating excitation source and the first sensing unit is closed, specifically, in the switch switching module corresponding to the pth row of sensing units, the switch S p1 is closed;

[0019] (6) In the switch switching module corresponding to each row of sensing units, the switch connecting the first sensing unit and the qth sensing unit in the same row is closed, and the reverse connection of the two sensing units should be realized, specifically, in the pth row of switch switching modules, the switch S pqClose, realize the anti-serial connection of the sensing unit p1 and the sensing unit pq;

[0020] (7) Detect the voltage of the output end of each switch switching module, and compare the detected voltage with delta u. If the detected voltage exceeds delta u, it is determined that there is a foreign object in the range covered by the anti-serial sensing unit at this time, and step (8) is entered. If the detected voltage does not exceed delta u, it is determined that there is no foreign object in the range covered by the anti-serial sensing unit at this time, and step (9) is entered. Specifically, the switch switching module corresponding to the Pth row of sensing units should detect the output voltage of OUT pa and OUT pb , and compare it with delta u.

[0021] (8) Turn off S p1 , S pq , and stop charging, and send an alarm message indicating the number of anti-serial sensing units, thereby indicating the location of the foreign object.

[0022] (9) The variable q is incremented by 1, and steps (6)-(8) are repeated. In this way, the switch switching module corresponding to each row of sensing units is turned off and turned on through the built-in switch to realize the anti-serial connection of different sensing units and the first sensing unit in the row.

[0023] (10) When q is incremented to greater than the total number of sensing units in the row, it is reset to 2, and steps (6)-(8) are repeated.

[0024] (11) Until the charging is completed or a shutdown instruction is received, the system is shut down, and the foreign object detection system is shut down.

[0025] Further, in step (6), when the sensing unit p1 and the sensing unit pq are connected in anti-series, the resonance capacitance value of the sensing unit pq is calculated according to the following formula:

[0026]

[0027] Where C p1 is the resonance capacitance value of the first sensing unit in the Pth row of sensing units; f d is the foreign object detection frequency; L p1 is the inductance value of the first sensing unit in the Pth row of sensing units; L pq is the inductance value of the qth sensing unit in the Pth row of sensing units, and C p1 , f d , L p1 , L pq are known values that need to be determined first during the design and production of the system.

[0028] Compared with the prior art, the present application has the following positive and beneficial effects:

[0029] (1) The array type sensing coil is used for foreign matter detection, under the action of an external alternating excitation source, when there is no foreign matter in the detection area, the detection circuit resonates, the output voltage is a certain value and is 0 in theory, when there is foreign matter in the detection area, the resonance property of the detection circuit is destroyed, the output voltage increases significantly, according to which a threshold is reasonably set and the detection output voltage is compared with the threshold to judge, so that the foreign matter detection of the wireless charging system can be realized.

[0030] (2) The array type sensing coil densely arranged on the whole energy emission plane is used for foreign matter detection, so that the elimination of the direct blind area of the foreign matter detection system can be realized, and since a sensing unit with a smaller size compared with the whole energy emission plane is used, the precision of the foreign matter detection can reach a high level.

[0031] (3) The single-layer coil array type coil is used, compared with the double-layer or multi-layer foreign matter detection system, the structural complexity of the sensing coil is reduced, and since the foreign matter detection coil is generally laid on the energy emission coil, the single-layer structure can effectively avoid the sacrifice of the energy transmission distance of the wireless power transmission system caused by the foreign matter detection sensing coil;

[0032] (4) The array type sensing coil is made of the PCB process, the process is mature, the production precision is high, the design requirements can be met, and the resonant capacitor matched with the sensing unit can be placed outside the energy transmission area through reasonable PCB layout, so that the system has high integration, small size, and is easy to produce and put into use;

[0033] (5) The output ends of the array type sensing units are connected to the switch switching modules, and each row of sensing units corresponds to a switch switching module, the switch switching modules in each row realize the anti-serial connection of different sensing units and the first sensing unit in the row through the turn-off and turn-on of the built-in switch, so that during the working time of the foreign matter detection system, the array type sensing units present the dynamic working and stopping state in a certain frequency and rule, when a certain foreign matter happens to fall in the indirect blind area of a certain anti-serial sensing unit, other anti-serial sensing units can effectively detect the foreign matter, that is, the elimination of the indirect blind area is realized. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a detection indirect blind area schematic diagram of the array type sensing coil and the two sensing units for foreign matter detection in the application;

[0035] Figure 2 It is a layout schematic diagram of the magnetic coupling mechanism and the foreign matter detection single-layer array type sensing coil of the wireless power transmission system in the application;

[0036] Figure 3Fig. 1 is a schematic diagram of the anti-serial single-layer array sensing coil printed by PCB according to the present application (a, square anti-serial; b, trapezoidal anti-serial; c, rectangular anti-serial; d, triangular anti-serial);

[0037] Figure 4 Fig. 2 is a schematic diagram of the internal structure of the sensing unit according to the present application;

[0038] Figure 5 Fig. 3 is a schematic diagram of the circuit structure of the output terminal of the sensing unit connected to the switching module according to the present application;

[0039] Figure 6 Fig. 4 is a schematic diagram of the anti-serial connection of the sensing unit p1 and the sensing unit pq according to the present application;

[0040] Figure 7 Fig. 5 is a flowchart of the process of the single-layer array sensing coil foreign object detection system for the magnetic coupling resonant wireless power transmission according to the present application;

[0041] In the figure, the components represented by the respective reference numerals are as follows:

[0042] 1, receiving end magnetic shielding layer; 2, receiving end magnetic core; 3, receiving coil; 4, transmitting end magnetic core; 5, transmitting end magnetic shielding layer; 6, foreign object detection single-layer array sensing coil; 7, transmitting coil. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as a limitation of the present application.

[0044] EMBODIMENT

[0045] A single-layer array sensing coil foreign object detection system for magnetically coupled resonant wireless power transmission is disclosed. The system includes a transmitter and a receiver. The transmitter includes a single-layer array sensing coil 6 for foreign object detection, a transmitting coil 7, a transmitting magnetic shielding layer 5, and a transmitting magnetic core 4. The receiver includes a receiving coil 3, a receiving magnetic shielding layer 1, and a receiving magnetic core 2. The receiver and transmitter are positioned vertically opposite each other. The receiving magnetic shielding layer 1 is placed above the receiving magnetic core 2, and the receiving coil 3 is placed below the receiving magnetic core 2. The receiving coil 3 and the single-layer array sensing coil 6 for foreign object detection are positioned vertically opposite each other. The single-layer array sensing coil 6 is closely positioned above the transmitting coil 7, and the transmitting magnetic core 4 and the transmitting magnetic shielding layer 5 are sequentially placed below the transmitting coil 7. The overall size of the single-layer array sensing coil 6 is equal to or slightly larger than the effective area of ​​the energy emission plane, thereby achieving effective coverage of the entire energy coupling area. The magnetic coupling mechanism and the layout of the single-layer array sensing coil for foreign object detection in the wireless power transmission system are as follows: Figure 2 As shown.

[0046] The foreign object detection single-layer array sensing coil 6 consists of several small sensing units. These sensing units are evenly and densely distributed, completely covering the entire detection area without leaving any gaps, thereby minimizing the direct blind zone of foreign object detection. Each sensing unit is a planar spiral coil, and its outer contour can be triangular, quadrilateral, pentagonal, hexagonal, or any other shape suitable for close arrangement without gaps. The other shapes suitable for close arrangement without gaps do not include circles and ellipses. The specific dimensions of each sensing unit are determined according to the required accuracy and area. The single-layer array sensing coil is manufactured using PCB printing. Figure 3 The diagram shows a single-layer array of anti-series sensor coils printed on a PCB, where (a) is a square anti-series; (b) is a trapezoidal anti-series; (c) is a rectangular anti-series; and (d) is a triangular anti-series.

[0047] Each of the plurality of sensing units contains a resonant capacitor that matches the foreign object detection single-layer array sensing coil, specifically as follows: Figure 4 As shown, in Figure 4 In this diagram, L represents a planar wound sensing coil located within the energy coupling region of the wireless power transmission system. R is a protective resistor, and C is a resonant capacitor. Both R and C should be designed and positioned outside the energy coupling region. The specific calculation method for the capacitance value of the resonant capacitor C is described below.

[0048] The output of each of the plurality of sensing units is connected to a switch switching module, specifically as follows: Figure 5As shown, the switch switching power module is used to realize different sensing units in anti-series connection. Taking the switch switching module 1 as an example, the output terminals of the sensing units in the first row are connected to the switch switching module, the sensing unit 11 is connected to the sensing unit 12 through the switch S 12 , S 13 ……, S 1(n-1) , S 1n , S 12 , S……, S 1(n-1) , S 1n respectively, and the sensing unit 1n to realize anti-series connection, and can ensure that any two sensing units are in anti-series connection with an external alternating excitation source u and a current limiting protection resistor in series to realize active detection and ensure safe operation of detection.

[0049] The present application will be explained in detail as follows: Figure 5

[0050] ① The gray area represents the energy emission plane. For the convenience of display, the gray gap shown in the picture is large. In the real situation, each sensing unit should be densely distributed in the entire energy emission plane without gap or with a small gap that can be ignored.

[0051] ② The sensing array size is m x n, m represents the total number of array coils, and n represents the total number of sensing units contained in each row of sensing coils. The geometric design of each sensing unit is the same, and the same purpose is to ensure that any two sensing units are in anti-series connection to realize the decoupling of the foreign matter detection magnetic field and the energy emission magnetic field.

[0052] ③ The output of each row of sensing units is connected to a switch switching module, and the output of each switch module is connected to an external alternating excitation u.

[0053] ④ For the convenience of representation, only the circuit diagram of the switch switching module 1 is shown in the figure, and the rest of the switch switching modules are shown in corresponding colors, and are not detailed, but the overall situation is the same as that of the switch switching module 1, and different switch switching modules corresponding to each row of sensing units are connected in parallel.

[0054] ⑤ In the switch switching module 1, S 12 , S……, S 1(n-1) , S 1n and other switches are AC switches such as bidirectional thyristors, and have the ability to pass high-frequency AC power. The same is true for other switch switching modules.

[0055] ⑥ The IN port represents the input end of each switch switching module (also the output end of the sensing unit), the OUT port represents the output end of each switch switching module, and the lower right corner mark represents the serial number, that is, each switch switching module has 2n inputs and 2 outputs without considering other controls.

[0056] The frequency of the external alternating excitation source u is consistent with the detection frequency to achieve resonance, and the resonance frequency should be far away from the frequency of wireless charging power transmission and the possible split frequency point, so as to minimize the mutual interference between the power transmission frequency and the foreign matter detection frequency.

[0057] Taking the pth(p≤m) row of each sensing unit as an example, the calculation method of the resonance capacitance value is described as follows:

[0058] 1) The inductance value L of each sensing unit p1 , L p2 , … are known, and the protection resistances R p1 , R p2 , … are known;

[0059] 2) The foreign matter detection frequency f d is a fixed value;

[0060] 3) Each sensing unit is an LCR series circuit, and in the sensing unit p1, the resonance capacitance value C

[0061]

[0062] 4) When the sensing unit p1 and the sensing unit pq(q≠1, and q≤n) realize anti-series, as shown in Figure 6 , set

[0063]

[0064] wherein, C p1 is the resonance capacitance value of the first sensing unit in the pth row of sensing units; f d is the foreign matter detection frequency; L p1 is the inductance value of the first sensing unit in the pth row of sensing units; L pq is the inductance value of the qth sensing unit in the pth row of sensing units, and C p1 , f d , L p1 , L pq are known values that need to be determined first when the system is designed and produced;

[0065] 5) The protection resistances R p1 , R p2 , … can be appropriately valued.

[0066] Generally, the inductance values of each sensing unit will have different degrees of differences due to various factors, and the above value method ensures that resonance can be achieved in any group of anti-series sensing units.

[0067] A blind elimination method for single-layer array sensing coil type foreign matter detection of magnetic coupling resonance wireless power transmission using the above detection system, comprising the following steps:

[0068] (1) Set the detection accuracy as δu, ideally δu is set to 0, but considering the influence of the energy transmission system on the foreign matter detection system and environmental noise, δu is reasonably set according to the actual application scene;

[0069] (2) Set the integer variable as q = 2;

[0070] (3) In the standby state of the wireless power transmission system, continuously monitor whether the system receives a charging instruction;

[0071] (4) If a charging instruction is received, charging begins, and the foreign matter detection system also begins to work;

[0072] (5) In the switch switching module corresponding to each row of sensing units, the switch connecting the external alternating excitation source and the first sensing unit is closed, specifically, in the switch switching module corresponding to the pth row of sensing units, switch Sp1 is closed; p1 ;

[0073] (6) In the switch switching module corresponding to each row of sensing units, the switch connecting the first sensing unit and the qth sensing unit in the row is closed, and the anti-serial connection of the two sensing units should be realized, specifically, in the pth row of switch switching modules, switch Spq is closed, realizing the anti-serial connection of sensing unit p1 and sensing unit pq; pq ;

[0074] (7) Detect the voltage at the output end of each switch switching module, and compare the detected voltage with δu, if the detected voltage exceeds δu, it is determined that there is foreign matter in the range covered by the anti-serial sensing units at this time, step (8) is entered, if the detected voltage does not exceed δu, it is determined that there is no foreign matter in the range covered by the anti-serial sensing units at this time, step (9) is entered, specifically, the switch switching module corresponding to the pth row of sensing units should detect the output voltage at the OUT pa and OUT pb ends, and compare it with δu;

[0075] (8) S p1 , S pq are opened, and charging is stopped, alarm information is sent, indicating the anti-serial sensing unit number, so as to show the position of the foreign matter;

[0076] (9) The variable q is incremented by 1, and steps (6)-(8) are repeated, so that the switch switching module corresponding to each row of sensing units realizes the anti-serial connection of different sensing units and the first sensing unit in the row through the turn-off and turn-on of the built-in switch respectively;

[0077] (10) When q is accumulated to be greater than the total number of sensing units in the row, it is reset to 2, and steps (6)-(8) are repeated;

[0078] (11) Until the charging is completed or the shutdown instruction is received, the system is shut down, and the foreign matter detection system is shut down.

[0079] The above detailed the structure, features and effects of the present application according to the embodiments shown in the drawings. The above description is only the preferred embodiments of the present application, but the present application is not limited to the embodiments shown in the drawings. Any changes or modifications made in accordance with the concept of the present application, or equivalent embodiments with equivalent changes, are still within the scope of the present application.

Claims

1. A single layer array of sensor coil type foreign object detection system applied to magnetic coupled resonant wireless power transfer, characterized by, The detection system comprises a transmitting end and a receiving end, the transmitting end comprises a foreign matter detection single-layer array sensing coil (6), a transmitting coil (7), a transmitting end magnetic shielding layer (5) and a transmitting end magnetic core (4), and the receiving end comprises a receiving coil (3), a receiving end magnetic shielding layer (1) and a receiving end magnetic core (2); the foreign matter detection single-layer array sensing coil (6) is composed of a plurality of small-size sensing units, the plurality of sensing units are uniformly and densely arranged, and the entire detection area is completely covered without any spare space; the overall size of the foreign matter detection single-layer array sensing coil is equal to or slightly larger than the effective area of the energy transmitting plane. A blind elimination method for foreign matter detection of a magnetic coupling resonant wireless power transmission system by using the detection system, comprising the following steps: (1) set the detection accuracy as δu, and ideally δu is set as 0, but considering the influence of the energy transmission system on the foreign matter detection system and environmental noise, δu is reasonably set according to the actual application scene; (2) preset the integer variable as q=2; (3) continuously monitor whether the system receives a charging instruction in the standby state of the wireless power transmission system; (4) if the charging instruction is received, the charging starts, and the foreign matter detection system starts to work at the same time; (5) In the switch switching module corresponding to each row of sensing units, the switch connected with the first sensing unit is closed, specifically, in the switch switching module corresponding to the pth row of sensing units, the switch S p1 is closed. (6) In the switch switching module corresponding to each row of sensing units, the switch connected between the first sensing unit and the qth sensing unit of the current row is closed, and the anti-series connection of the two sensing units should be realized. Specifically, in the pth row switch switching module, the switch S pq is closed to realize the anti-series connection of the sensing unit p1 and the sensing unit pq. (7) detecting the voltage at the output end of each switch switching module, and comparing the detected voltage with δu, if the detected voltage exceeds δu, it is determined that there is a foreign object in the range covered by the anti-serial sensing unit at this time, step (8) is entered, if the detected voltage does not exceed δu, it is determined that there is no foreign object in the range covered by the anti-serial sensing unit at this time, step (9) is entered, specifically, the switch switching module corresponding to the Pth row of sensing unit should detect the output voltage of OUT pa and OUT pb end, and compare it with δu; (8) disconnect S p1 , S pq and stop charging, send alarm information, indicating anti-series sensing unit number, thereby showing the location of foreign matter. (9) the variable q is increased by 1, and steps (6)-(8) are repeated, so that the switch switching module corresponding to each row of sensing units is realized by the rotation of the built-in switch to realize the anti-series connection and voltage detection of different sensing units and the first sensing unit in the row; (10) when q is added to more than the total number of sensing units in the row, q is reset to 2, and steps (6)-(8) are repeated; (11) until the charging is completed or a shutdown instruction is received, the system is shut down, and the foreign matter detection system is shut down.

2. The single-layer array of sensor coils foreign object detection system for use in a magnetically coupled resonant wireless power transfer of claim 1, wherein, The receiving end and the transmitting end are arranged oppositely, wherein the receiving end magnetic shielding layer (1) is laid above the receiving end magnetic core (2), the receiving coil (3) is laid below the receiving end magnetic core (2), the receiving coil (3) and the foreign matter detection single-layer array sensing coil (6) are arranged oppositely, the foreign matter detection single-layer array sensing coil (6) is closely laid above the transmitting coil (7), and the transmitting coil (7) is sequentially laid below the transmitting end magnetic core (4) and the transmitting end magnetic shielding layer (5).

3. The single-layer array of sensor coils foreign object detection system for use in a magnetically coupled resonant wireless power transfer of claim 1, wherein, The foreign matter detection single-layer array sensing coil is printed by a PCB process.

4. The single-layer array of sensor coils foreign object detection system for use in a magnetically coupled resonant wireless power transfer of claim 1, wherein, The sensing unit is a planar spiral coil, and the outer contour of the planar spiral coil is a triangle, a quadrilateral, a pentagon, a hexagon or other various shapes suitable for close arrangement without gaps.

5. A single layer array of sensor coils foreign object detection system for use in a magnetically coupled resonant wireless power transfer according to claim 4, wherein, Each of the plurality of sensing units contains a resonant capacitor matched with the foreign matter detection sensing unit, and the resonant capacitor is arranged outside the wireless charging energy coupling area by a PCB layout.

6. The single-layer array of sensor coils foreign object detection system for use in a magnetically coupled resonant wireless power transfer of claim 5, wherein, The output end of each of the plurality of sensing units is connected to a switch switching module, the switch switching module is used to realize reverse series connection of different sensing units, and can ensure that any two sensing units are in reverse series connection with an applied alternating excitation source u and a current limiting protection resistor in series to realize active detection and ensure safe operation of detection.

7. A single layer array of sensor coils foreign object detection system for use in a magnetically coupled resonant wireless power transfer according to claim 6, wherein, The frequency of the applied alternating excitation source u is consistent with the intrinsic frequency of the reverse series connection sensing unit.

8. The single-layer array sensing coil type foreign object detection system applied to magnetic coupling resonant wireless power transmission according to claim 1, wherein when the sensing unit p1 and the sensing unit pq are in reverse series connection in step (6), the resonance capacitance value of the sensing unit pq is calculated according to the following formula: wherein C p1 is the resonant capacitance value of the first sensor unit in the pth row of sensor units; f d is the foreign object detection frequency; L p1 is the inductance value of the first sensor unit in the pth row of sensor units; L pq is the inductance value of the qth sensor unit in the pth row of sensor units, and C p1 、 f d 、 L p1 , L pq are known values that need to be determined first when the system is designed and produced.

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