Foreign object detection sensor of wireless power transmission system

Abstract

The present invention relates to a foreign object detection sensor for detecting a foreign object or an organism, applied to a wireless power transmission system. The foreign object detection sensor of a wireless power transmission system, according to the present invention, is located between a power transmission end coil and a power reception end coil in the wireless power transmission system so as to generate and detect a voltage or current change caused by capacitance generated between a foreign object and the foreign object detection sensor if the foreign object approaches or makes contact with the foreign object detection sensor. In the wireless power transmission system to which the foreign object detection sensor according to the present invention is applied, a foreign object can be detected with high reliability regardless of the type and size of the foreign object, and the foreign object or an organism can be detected across a wide user-specified range by adjusting the size or position of the foreign object detection sensor without affecting wireless power transmission.

Description

Foreign body detection sensor for wireless power transfer systems

[0001] The present invention relates to a sensor for detecting foreign substances or living organisms applied to a wireless power transmission system, and more particularly, to a sensor for detecting foreign substances or living organisms in a wireless power transmission device in a contact or non-contact manner.

[0002] When metallic foreign objects (metailic FOs) exist between the power transmitting (TX) terminal and the power receiving (RX) terminal for wireless power transfer, the coil of the transmitting (TX) terminal may heat up due to impedance mismatch, which may cause damage to the circuit and problems with the stability of the system. In particular, in the case of wireless charging systems for electric vehicles, since high power is required, the heating of the coil can lead to overheating of the entire system. In addition to metallic foreign objects, the presence of living objects (LOs) can pose a threat to life. For this reason, foreign object detection (FOD) technology is essential for wireless charging products.

[0003] Another conventional technology is to place a detection coil between a transmitter coil and a receiver coil, so that when a metallic foreign substance is inserted, the inductance (L) of the detection coil changes, and this change is compared with a reference value (a mutually symmetrical L). However, in this case, although it recognizes relatively well when the metallic foreign substance is large, it is difficult to use because the change in L is very small to detect when a small metal is inserted. In addition, the higher the power transmission output of the transmitter, the higher the false recognition rate. This is because when a detection coil is used in a high-output power transmission wireless charging system, there is a high possibility that the mutual balance will be broken due to the phase change of the detection coil as the temperature rises. Therefore, there is a problem that the detection coil must be compensated for the temperature rise as the output of the transmitter is higher in order to detect accurate FO.

[0004] In addition, in the case of another prior art, a technology for detecting foreign substances by measuring the surface temperature of a transmission coil and the temperature of foreign substances, there was a problem that it was affected by the temperature of the external environment, and thus the detection time could be delayed.

[0005] (Patent Document 1) Korean Patent Publication No. 10-2022-0076328

[0006] The present invention provides a sensor for detecting foreign substances in a wireless power transmission system using a contact or non-contact detection method that solves the above-described problems.

[0007] A foreign substance detection sensor of a wireless power transmission system according to the present invention for solving the above problem is located between a transmitting coil and a receiving coil of the wireless power transmission system, and detects the approach or contact of a foreign substance by generating a voltage or current change due to capacitance generated between the foreign substance and the sensor.

[0008] In addition, a foreign substance detection sensor of a wireless power transmission system according to the present invention may include a plurality of ring parts in which a change in voltage or current is generated by static electricity formed on the surface of the foreign substance, a plurality of extension parts formed to be long and extended from one end of the ring parts, and a signal transmission part connected to the extension parts to transmit a signal of a change in voltage or current generated in the ring parts.

[0009] In addition, the ring portion of the foreign substance detection sensor of the wireless power transmission system according to the present invention may have a gap formed in a part thereof that is opened so that an induced current is not generated by a magnetic field generated from the transmission coil.

[0010] In addition, the ring portion of the foreign substance detection sensor of the wireless power transmission system according to the present invention may have a polygonal shape.

[0011] Additionally, the ring portion of the foreign substance detection sensor of the wireless power transmission system according to the present invention can be formed in a circular shape.

[0012] By using a contact or non-contact sensor according to the present invention, foreign substances can be detected with high reliability regardless of the type and size of the foreign substances in a wireless power transmission system, and by adjusting the size or location of the foreign substance detection sensor without affecting wireless power transmission, there is an effect that foreign substances or living organisms can be detected in a wide range desired by users.

[0013] Figure 1 is a block diagram of a foreign substance detection device in a wireless power transmission system according to the present invention.

[0014] Figure 2 is a configuration diagram of a foreign substance detection sensor in a foreign substance detection device according to the present invention.

[0015] Figure 3 is an example of the shape of a foreign substance detection sensor of a foreign substance detection device according to the present invention.

[0016] Figure 4 is a detailed configuration diagram of a foreign substance detection sensor according to one embodiment of the present invention.

[0017] Figure 5 is a detailed configuration diagram of a foreign substance detection sensor according to another embodiment of the present invention.

[0018] The advantages and features of the present invention, and the methods for achieving them, will become clear with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Meanwhile, the terminology used in this specification is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated in the phrase. The terms "comprises" and / or "comprising" as used in the specification do not exclude the presence or addition of one or more other components, steps, operations, and / or elements mentioned.

[0019] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0020]

[0021] The present invention will be described in detail with reference to the drawings below.

[0022] FIG. 1 is a block diagram of a foreign substance detection device in a wireless power transmission system according to the present invention, and its components may include a power transmission unit (100), a transmission coil (200), a control unit (300), a foreign substance detection unit (400), a foreign substance detection sensor (500), and an antenna (600).

[0023] The power transmission unit (100) performs the function of supplying power to the transmission coil (200) so that power can be transmitted wirelessly.

[0024] The transmission coil (200) performs the function of enabling wireless power transmission by forming a magnetic field when receiving power from the power transmission unit (100) and transmitting power to the receiving coil of the electric vehicle through this field.

[0025] The control unit (300) receives information when the foreign substance detection unit (400) detects the presence of a foreign substance or a living organism, and performs a function of controlling the power transmission unit (100) to stop wireless power transmission.

[0026] The foreign substance detection unit (400) performs the function of detecting whether a foreign substance approaches or comes into contact with the foreign substance detection sensor (500) and providing the information to the control unit (300).

[0027] It can perform a function of applying electromagnetic waves to a foreign substance through an antenna (600) or applying an electric field of a predetermined size to form static electricity of a predetermined size on the surface of the foreign substance.

[0028] Meanwhile, the detailed configuration and operating principle of the foreign substance detection sensor (500) are similar to the principle of the touch pad, and the detailed structure and operating principle thereof are described in detail in Korean Patent Registration No. 10-2072647, so a detailed description thereof is omitted in this specification.

[0029] FIG. 2 is a configuration of a foreign substance detection sensor in a foreign substance detection device according to the present invention, and the configuration includes a transmission coil (200), an antenna (600), a foreign substance detection sensor (500), and an electric vehicle receiving coil.

[0030] The transmission coil (200) generates a magnetic field and performs the function of wirelessly transmitting power to the receiving coil of the electric vehicle.

[0031] The antenna (600) can emit electromagnetic waves of a predetermined size and frequency to the surrounding area or form an electric field of a predetermined size to generate static electricity on the surface of a foreign substance that approaches or comes into contact with it.

[0032] The foreign substance detection sensor (500) generates a capacitance of a predetermined size between itself and the foreign substance when the foreign substance approaches or comes into contact with the foreign substance, and as a result, a change in voltage or current occurs, enabling the foreign substance detection unit (400) to determine whether or not the foreign substance is present.

[0033] FIG. 3 is an example of the shape of a foreign substance detection sensor (500) of a foreign substance detection device according to the present invention. The foreign substance detection sensor (500) according to the present invention may be formed to be the same size as the transmission coil or larger if necessary, and may be installed to the outside of the transmission coil. It is preferable that the shape of the foreign substance detection sensor (500) according to the present invention not include a closed loop shape so as to prevent an induced current from being generated by a magnetic field generated from the transmission coil (200). This can prevent energy loss and fire hazards.

[0034] FIG. 4 is a detailed configuration diagram of a foreign substance detection sensor according to one embodiment of the present invention, and FIG. 5 is a detailed configuration diagram of a foreign substance detection sensor according to another embodiment of the present invention.

[0035] A foreign substance detection sensor according to the present invention includes a ring portion (501), a gap (502), an extension portion (503), and a signal transmission portion (504).

[0036] The ring part (501) causes a change in voltage or current when a capacitance of a predetermined size is formed between the ring part (501) and the foreign substance or living substance due to static electricity formed on the surface of the foreign substance or living substance that is approaching or in contact with the ring part (501). Here, in order to prevent an induced current from being generated by a magnetic field generated by a transmission coil (200), a gap (502) may be formed at a predetermined location so that an electrical closed loop is not formed. It is preferable that the ring part (501) be formed in multiple pieces as needed, and the size thereof may also be changed and applied.

[0037] The above ring portion (501) can be formed in various polygonal shapes such as a triangle, square, pentagon, hexagon, or circular shape.

[0038] The extension part (503) is formed to be extended long from one end of the ring part (501) so as to transmit a signal of change in voltage or current generated in the ring part (501) to the outside.

[0039] The signal transmission unit (504) is connected to a plurality of extension units (503) to transmit voltage or current change signals generated from the ring units (501) to the foreign substance detection unit (400) so as to determine whether a foreign substance is present.

[0040] While the composition of the present invention has been described in detail with reference to the accompanying drawings, this is merely an example, and it will be apparent to those skilled in the art that various modifications and changes may be made within the technical scope of the present invention. Therefore, the scope of protection of the present invention is determined by the claims described below rather than the detailed description above, and all changes or modifications derived from the claims and their equivalent concepts should be interpreted as being included within the technical scope of the present invention.

[0041] [Explanation of symbols]

[0042] 100: power transmission unit, 200: transmitter coil, 300: control unit, 400: foreign substance detection unit

[0043] 500: Foreign substance detection sensor, 600: Antenna,

[0044] 501: ring part, 502: gap, 503: extension part, 504: signal transmission part

Claims

1. In a wireless power transmission system, A foreign substance detection sensor of a wireless power transmission system, which is located between a transmitting coil and a receiving coil and detects the approach or contact of a foreign substance by generating a voltage or current change due to capacitance generated between the foreign substance and the sensor.

2. In paragraph 1, A plurality of ring parts in which changes in voltage or current occur due to static electricity formed on the surface of the foreign substance, A plurality of extensions formed by extending from one end of the above-mentioned ring sections, and A foreign substance detection sensor of a wireless power transmission system including a signal transmission unit that is connected to the above extension units and transmits a signal of change in voltage or current generated in the ring unit.

3. In paragraph 2, A foreign substance detection sensor of a wireless power transmission system in which the above-mentioned ring portion has a gap formed that opens a portion thereof to prevent an induced current from being generated by a magnetic field generated from the above-mentioned transmission coil.

4. In paragraph 2, The above ring part is a foreign substance detection sensor of a wireless power transmission system having a polygonal shape.

5. In paragraph 2, The above ring part is a foreign substance detection sensor of a wireless power transmission system having a circular shape.

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