Foreign object detection device of wireless power transmission system

Abstract

The present invention relates to a foreign object detection device for detecting a foreign object or a living object, which is applied to a wireless power transmission system. The foreign object detection device in a wireless power transmission system according to the present invention includes: a foreign object detection sensor which is disposed between a transmission terminal coil and a reception terminal coil and corresponds to a contact or non-contact detection sensor; and a foreign object detection unit for determining whether a foreign object exists according to whether a voltage or a current generated from the foreign object detection sensor is changed when a predetermined foreign object approaches or contacts. According to the present invention, a foreign object can be detected with high reliability regardless of the type and size of the foreign object in a wireless power transmission system, and a foreign object and a living object can be detected in a wide range desired by users by adjusting the size or position of the foreign object detection sensor without affecting wireless power transmission.

Description

Foreign body detection device for wireless power transmission system

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

[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] One prior art technique, the Q-factor, which characterizes the characteristics of wireless power transmission systems, was used to determine the presence of foreign matter affecting the transmitter and receiver. However, as we move toward high-power power transmission systems, simple Q-factor measurement becomes increasingly difficult to use to detect FOD across a wide range of sizes (especially very small metals) and at varying distances.

[0004] In addition, another conventional technology, when a detection coil is placed between a transmitter coil and a receiver coil, the inductance (L) of the detection coil changes when a metallic foreign substance is inserted, and the operation is performed by comparing this change with a reference value (mutually symmetrical L). However, in this case, although it recognizes relatively well when a 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 more rapidly the false recognition rate increases. 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.

[0005] 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.

[0006] (Patent Document 1) Korean Patent Publication No. 10-2022-0076328

[0007] The present invention provides a device for detecting foreign substances in a wireless power transmission system using a contact or non-contact detection method that solves the above-described problems.

[0008] In order to solve the above problem, a foreign substance detection device of a wireless power transmission system according to the present invention is disposed between a transmitting coil and a receiving coil and includes a foreign substance detection sensor which is a contact or non-contact detection sensor and a foreign substance detection unit which determines whether a foreign substance exists based on whether a voltage or current generated in the foreign substance detection sensor changes when a predetermined foreign substance approaches or comes into contact with it.

[0009] In addition, the foreign substance detection device of the wireless power transmission system may further include an antenna that applies a predetermined electromagnetic wave to the foreign substance.

[0010] In addition, the foreign substance detection device of the wireless power transmission system may further include a control unit that stops wireless power transmission performed through the transmission coil when the foreign substance detection unit determines that a foreign substance is present.

[0011] In addition, the foreign substance detection device of the wireless power transmission system may form a capacitance of a predetermined size between the foreign substance detection sensor and the foreign substance.

[0012] In addition, the foreign substance detection device of the wireless power transmission system may be formed in a shape that does not include a closed loop shape so that an induced current is not generated by the magnetic field generated from the transmission coil.

[0013] According to the present invention, in a wireless power transmission system, foreign substances can be detected with high reliability regardless of the type and size of the foreign substances, and the size or position of a foreign substance detection sensor can be adjusted without affecting wireless power transmission, thereby enabling detection of foreign substances or living organisms in a wide range desired by users.

[0014] Figure 1 is a block diagram of a foreign substance detection device in a wireless power transmission system according to the present invention.

[0015] Figure 2 is a configuration diagram of a foreign substance detection sensor in a foreign substance detection device according to the present invention.

[0016] 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.

[0017]

[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] 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.

[0035] [Explanation of symbols]

[0036] 100: power transmission unit, 200: transmitter coil, 300: control unit, 400: foreign substance detection unit

[0037] 500: Foreign substance detection sensor, 600: Antenna

Claims

1. In a wireless power transmission system, A foreign matter detection sensor, which is a contact or non-contact detection sensor, is placed between the transmission coil and the receiving coil. A foreign substance detection unit that determines whether a foreign substance exists based on whether there is a change in voltage or current generated in the foreign substance detection sensor when a certain foreign substance approaches or comes into contact with the foreign substance. A foreign matter detection device of a wireless power transmission system including a .

2. In paragraph 1, A foreign substance detection device of a wireless power transmission system further equipped with an antenna that applies a predetermined electromagnetic wave to the foreign substance.

3. In paragraph 1, A foreign substance detection device of a wireless power transmission system further comprising an antenna that generates an electric field of a predetermined size in the surroundings and induces static electricity of a predetermined size in the foreign substance.

4. In paragraph 1, A foreign substance detection device of a wireless power transmission system further comprising a control unit that stops wireless power transmission performed through the transmission coil when the foreign substance detection unit determines that a foreign substance is present.

5. In paragraph 1, The above foreign substance detection sensor is a foreign substance detection device of a wireless power transmission system formed in a shape that does not include a closed loop shape so that an induced current is not generated by a magnetic field generated from the above transmission coil.

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