Radio power transmission control method and apparatus

Abstract

To provide a wireless power transmission control method and a device that are for wireless charging and can not only more effectively and accurately detect foreign objects but also minimize unnecessary charging interruptions.SOLUTION: A wireless power transmission control method for a wireless power transmitter includes: a first packet receiving step of receiving a foreign object detection status packet; a first determination step of determining whether a foreign object exists based on the foreign object detection status packet; and a power control step of controlling power based on a determination result in the first determination step. The power control step includes a first power transmission mode in which a first power is transmitted when it is determined that there is no foreign object as the determination result in the first determination step, and a second power transmission mode in which a second power is transmitted when it is determined that there is a foreign object as the determination result in the first determination step.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a wireless power transmission technology, and more particularly to a wireless power transmission control method for wireless charging. and relating to the device. [Background technology]

[0002] Recently, with the rapid development of information and communication technology, ubiquitous computing based on information and communication technology has become a reality. It is becoming a meeting.

[0003] In order for information and communication devices to be connected anytime and anywhere, all facilities in society must be equipped with communication functions. A sensor with a built-in computer chip must be installed. Therefore, the power supply problem for these devices and sensors has become a new issue. as well as Bluetooth handsets and music players like iPods With the rapid increase in the number of types of portable devices, the task of charging batteries is becoming increasingly time-consuming for users. This has required time and effort. The technology has recently gained interest.

[0004] Wireless power transmission technology wireless energy transfer) is a technology that uses the magnetic field induction principle to It is a technology that transmits electrical energy from a transmitter to a receiver by using a wire. Electric motors and transformers using the principle of magnetic induction began to be used, followed by high frequency and microwave. We are also trying to transmit electrical energy by emitting electromagnetic waves such as owave and laser. The electric toothbrushes and some wireless razors that we use often are actually charged using the electromagnetic induction principle. I'm electrified.

[0005] To date, energy transmission methods using wireless technology can be broadly classified into magnetic induction, magnetic resonance (Electromagnetic Resonance), and RF transmission using short-wavelength radio frequencies. and so on.

[0006] The magnetic induction method involves placing two coils adjacent to each other. When an electric current is passed through one coil, the magnetic flux generated at this time induces an electromotive force in the other coil. This technology, which mainly focuses on small devices such as mobile phones, has seen rapid commercialization. The magnetic induction method can transmit power of up to several hundred kilowatts (kW) with high efficiency. However, its maximum transmission distance is less than 1 centimeter (cm), so it generally has the drawback that it must be adjacent to a charger or the bottom.

[0007] The magnetic resonance method is characterized by using electric and magnetic fields instead of electromagnetic waves or currents. Since the magnetic resonance method is hardly affected by electromagnetic wave problems, it has the advantage of being safe for other electronic devices and the human body. On the other hand, it can only be utilized within a limited distance and space, and has the drawback of relatively low energy transmission efficiency.

[0008] The short-wavelength wireless power transmission method - simply, the RF transmission method - utilizes the fact that energy can be directly transmitted and received in the form of radio waves. This technology is an RF-based wireless power transmission method using a rectenna. A rectenna is a combination of an antenna and a rectifier, meaning an element that directly converts RF power into DC power. That is, the RF method converts AC radio waves into DC ​​​​​​​​​​​​​A technology to be converted and used, with its efficiency recently improved, leading to active research on commercialization. It is progressing.

[0009] Wireless power transmission technology can be utilized in various industries, not only in mobile, but also in IT, railway, home appliance industries, etc. It can be utilized.

[0010] When there is a conductor other than a wireless power receiver - that is, a foreign object (FO: Foreign Object) - in the wireless charging area, electromagnetic signals sent from the wireless power transmitter can be induced in the FO, causing the temperature to rise. As an example, the FO can include coins, clips, pins, ballpoint pens, etc. electromagnetic signals, and the temperature can rise. As an example, the FO can include coins, clips, pins, ballpoint pens, etc. It can include items such as coins, clips, pins, ballpoint pens, etc.

[0011] If there is an FO between the wireless power receiver and the wireless power transmitter, not only will the wireless charging efficiency drop significantly, but the temperatures of both the wireless power receiver and the wireless power transmitter can rise due to the increase in the surrounding temperature caused by the FO. If the FO located in the charging area is not removed, not only will power be wasted, but damage to the wireless power transmitter and the wireless power receiver can be caused by overheating. surrounding temperature rise due to the FO can cause the temperatures of both the wireless power receiver and the wireless power transmitter to rise. If the FO located in the charging area is not removed, not only will power be wasted, but damage to the wireless power transmitter and the wireless power receiver can be caused by overheating. If the FO located in the charging area is not removed, not only will power be wasted, but damage to the wireless power transmitter and the wireless power receiver can be caused by overheating. damage to the wireless power transmitter and the wireless power receiver can be caused by overheating. It can cause damage.

[0012] Also, even if there is actually no FO in the charging area, if the wireless power transmitter misjudges that there is a foreign object in the charging area, charging may be interrupted. charging may be interrupted.

[0013] Therefore, accurately detecting the FO located in the charging area has emerged as an important issue in the field of wireless charging technology. It has emerged as an important issue.

Summary of the Invention

Problems to be Solved by the Invention

[0014] The present invention was devised to solve the problems of the aforementioned prior art, and the object of the present invention is to provide a wireless power transmission control method and apparatus for wireless charging.

[0015] Another object of the present invention is to provide a wireless power transmitter capable of more accurately detecting foreign objects thereby.

[0016] Still another object of the present invention is to provide a wireless power transmission control method and apparatus capable of preventing unnecessary charging interruptions by minimizing foreign object detection errors thereby.

[0017] Still another object of the present invention is to provide a wireless power transmitter that prevents damage to equipment caused by foreign objects and enables continuous charging through adaptive transmission power control based on the presence or absence of foreign objects thereby. Still another object of the present invention is to provide a wireless power transmitter that prevents damage to equipment caused by foreign objects and enables continuous charging through adaptive transmission power control based on the presence or absence of foreign objects

[0018] The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary knowledge in the technical field to which the present invention pertains from the following description thereby.

Means for Solving the Problems

[0019] The present invention can provide a wireless power transmission control method and an apparatus therefor.

[0020] The wireless power transmission control method of a wireless power transmitter according to an embodiment of the present invention includes a first packet reception step of receiving a foreign object detection status packet, a first determination step of determining the presence or absence of a foreign object based on the foreign object detection status packet, and a power control step of controlling power based on the determination result of the first determination step. The power control step is when the determination result of the first determination step is that there is a foreign object and based on the determination result of the first determination step, a power control step of controlling power is included, and in the power control step, when the determination result of the first determination step is that there is a foreign object and A first power transmission mode that transmits the first power when judged, and a second power transmission mode that transmits the second power when judged that there is no foreign object as a result of the judgment in the first judgment stage can be included. When it is judged that there is no , a second power transmission mode that transmits the second power can be included.

[0021] Here, the second power is greater than the first power, and the power can be increased or decreased between the first power and the second power based on changes in the power transmission environment and then transmitted. Based on changes in the environment, the power can be increased or decreased between the first power and the second power and then transmitted. It can be transmitted.

[0022] Here, the first power can be 5W.

[0023] Also, the second power can be 15W.

[0024] Also, the wireless power transmission control method can include a second judgment stage for judging the presence or absence of a foreign object in the first power transmission mode. It can include a second judgment stage for judging the presence or absence of a foreign object.

[0025] Also, the second judgment stage can include at least one of a third judgment stage for judging the presence or absence of a foreign object based on transmission power loss and a fourth judgment stage for judging the presence or absence of a foreign object based on temperature change. It can include at least one of a third judgment stage for judging the presence or absence of a foreign object based on transmission power loss and a fourth judgment stage for judging the presence or absence of a foreign object based on temperature change. It can include at least one of them.

[0026] Here, the third judgment stage can include a stage of measuring the intensity of the transmission power, a stage of receiving information regarding the intensity of the received power corresponding to the transmission power from a wireless power receiver, a stage of estimating power loss based on the difference value between the intensity of the transmission power and the intensity of the received power, and a stage of comparing the estimated power loss with a predetermined power loss reference value for a certain period of time to judge the presence or absence of a foreign object. A stage of receiving information regarding the intensity of the received power corresponding to the transmission power from a wireless power receiver, a stage of estimating power loss based on the difference value between the intensity of the transmission power and the intensity of the received power, and a stage of comparing the estimated power loss with a predetermined power loss reference value for a certain period of time to judge the presence or absence of a foreign object can be included. Based on the difference value between the intensity of the transmission power and the intensity of the received power, a stage of estimating power loss, and a stage of comparing the estimated power loss with a predetermined power loss reference value for a certain period of time to judge the presence or absence of a foreign object can be included. A stage of comparing the estimated power loss with a predetermined power loss reference value for a certain period of time to judge the presence or absence of a foreign object can be included. It can include.

[0027] Also, the fourth judgment stage can include a stage of measuring the temperature of the charging area and a stage of judging the presence or absence of a foreign object based on the measured temperature. calculating a temperature change for a certain period of time based on the calculated temperature change and a temperature change standard; A step of comparing the values to determine whether or not a foreign object is present can be included.

[0028] If it is determined in the second determining step that a foreign object is present, the power transmission is interrupted. If it is determined that there is no foreign object as a result of the second determination step, the first power transmission mode is switched to the to the second power transfer mode.

[0029] A method for controlling wireless power transmission of a wireless power transmitter according to another embodiment of the present invention includes: a first packet receiving step of receiving a packet and determining whether a foreign object exists based on the foreign object detection status packet; A first determination step for determining whether or not a foreign object is present, and a second determination step for determining whether or not a foreign object is present. If the first power is transmitted, it is determined that there is no foreign object in the first determining step. and transmitting a power between the first power and the second power, and transmitting the first power. and a second determination step of determining whether or not a foreign object is present, the second determination step being based on a transmission power loss. The third judgment stage is to judge whether or not a foreign object is present based on the temperature change. It may include at least one fourth determination step for determining non-existence.

[0030] A wireless power transmitter according to yet another embodiment of the present invention includes an antenna for transmitting wireless power and a front a demodulator for demodulating a signal including a foreign object detection status packet received from the antenna; a controller that determines whether a foreign object is present or not based on the foreign object detection status packet; If the presence of a foreign object is determined as a result of the primary determination, the first power If it is determined that there is no foreign object as a result of the first determination step, It can be controlled such that electric power is transmitted from the first electric power to the second electric power.

[0031] Also, when the controller determines that there is a foreign object in the first determination result, during the transmission of the first electric power it is possible to make a secondary determination of the presence or absence of a foreign object.

[0032] Here, the secondary determination includes at least one of a third determination for determining the presence or absence of a foreign object based on transmission power loss and a fourth determination for determining the presence or absence of a foreign object based on temperature change. It can be done.

[0033] Also, the wireless power transmitter further includes a sensor that measures the intensity of the transmitted power and transmits it to the controller. In the third determination, the controller receives information regarding the intensity of the received power corresponding to the transmitted power through the demodulator, estimates the power loss based on the difference value between the intensity of the transmitted power and the intensity of the received power, and compares the estimated power loss with a predetermined power loss reference value over a certain period of time to determine the presence or absence of a foreign object. Furthermore, the sensor measures the temperature and transmits it to the controller. In the fourth determination, the controller calculates the temperature change over a certain period of time based on the measured temperature, and compares the calculated temperature change with a predetermined temperature change reference value to determine the presence or absence of a foreign object. Based on the difference value between the intensity of the transmitted power and the intensity of the received power, the power loss is estimated, and the estimated power loss over a certain period of time is compared with a predetermined power loss reference value to determine the presence or absence of a foreign object. Based on the difference value between the intensity of the transmitted power and the intensity of the received power, the power loss is estimated, and the estimated power loss over a certain period of time is compared with a predetermined power loss reference value to determine the presence or absence of a foreign object. Based on the difference value between the intensity of the transmitted power and the intensity of the received power, the power loss is estimated, and the estimated power loss over a certain period of time is compared with a predetermined power loss reference value to determine the presence or absence of a foreign object.

[0034] Also, when the controller determines that there is a foreign object in the determination result of the second determination stage, the power transmission is interrupted, and when it is determined that there is no foreign object in the determination result of the second determination stage, it can be controlled such that the electric power between the first electric power and the second electric power is transmitted. The controller calculates the temperature change over a certain period of time based on the measured temperature, and compares the calculated temperature change with a predetermined temperature change reference value to determine the presence or absence of a foreign object. Based on the calculated temperature change and a predetermined temperature change reference value, the presence or absence of a foreign object can be determined.

[0035] Also, when the controller determines that there is a foreign object in the determination result of the second determination stage, the power transmission is interrupted, and when it is determined that there is no foreign object in the determination result of the second determination stage, it can be controlled such that the electric power between the first electric power and the second electric power is transmitted. When it is determined that there is no foreign object in the determination result of the second determination stage, it can be controlled such that the electric power between the first electric power and the second electric power is transmitted. It can be controlled such that electric power is transmitted from the first electric power to the second electric power.

[0036] Also, the second power may be greater than the first power, and the first power may be 5W.

[0037] A method for controlling wireless power transmission in a wireless power transmitter according to still another embodiment of the present invention includes detecting a foreign object. a first packet receiving step of receiving an outgoing status packet and A first determination step for determining whether or not a foreign object is present, and a power supply control step for controlling the power supply based on the determination result of the first determination step. The first power adjusting stage may include adjusting the

[0038] Here, the first power adjustment step

[0039] If the result of the first determination step is that no foreign object is present, the guaranteed power is set to the second power, which is the initial setting. and if it is determined in the first determining step that a foreign object is present, the guaranteed power is maintained at the second The step of adjusting the power down from the first power to the second power can be included.

[0040] The first power may be 5W or less.

[0041] The second power may be 15W or less.

[0042] The wireless power transmission control method also includes a power supply that performs charging based on the adjusted power. The power transmission step and the power transmission step further include a second determination step for determining whether or not a foreign object is present. It is possible.

[0043] Here, the second determination step is

[0044] a third determination step of determining whether or not a foreign object is present based on the estimated power loss during charging; If a foreign object is detected as a result of the third determination step, the charging being performed is interrupted. obtain.

[0045] Here, the third determination step includes

[0046] a step of measuring the intensity of the transmitted power during charging and receiving information regarding the intensity of the received power corresponding to the transmitted power from the wireless power receiver, and a step of estimating power loss based on the difference value between the intensity before transmission and the intensity of the received power, and a step of comparing the estimated power loss with a predetermined power loss reference value for a certain period of time to determine the presence or absence of a foreign object. It can include a step of comparing the estimated power loss with a predetermined power loss reference value for a certain period of time to determine the presence or absence of a foreign object.

[0047] Also, the second determination step includes

[0048] a fourth determination step of determining the presence or absence of a foreign object based on the temperature change during charging. If the determination result of the fourth determination step is that a foreign object exists, the charging being performed can be interrupted.

[0049] Here, the fourth determination step includes

[0050] a step of measuring the temperature in the charging area, a step of calculating the temperature change over a certain period of time based on the temperature measurement result, and a step of comparing the calculated temperature change with a predetermined temperature change reference value to determine the presence or absence of a foreign object. It can include a step of comparing the calculated temperature change with a predetermined temperature change reference value to determine the presence or absence of a foreign object.

[0051] Also, if the determination result in the third determination step or the fourth determination step is that no foreign object exists, a renegotiation step of renegotiating the power transmission contract to reset the guaranteed power may be further included.

[0052] Also, the second determination step includes

[0053] a third determination step of determining the presence or absence of a foreign object based on the power loss estimated during charging, and if the determination result of the third determination step is that a foreign object exists, based on the temperature change measured during charging including a fourth determination step of determining the presence or absence of a foreign object, and if the determination result of the fourth determination step is that a foreign object exists, power transmission for charging may be interrupted within the predetermined time.

[0054] Further, the wireless power transmission control method further includes a step of transmitting a response based on the determination result of the first determination step, wherein the response is a response indicating the presence of a foreign object, and when the currently set guaranteed power exceeds the first power, the intensity of the power can be downward adjusted to below the first power.

[0055] Here, the first power may be 5W.

[0056] Further, the first determination step

[0057] includes a step of determining a quality factor threshold based on the reference quality factor value included in the foreign object detection status packet, and comparing the pre-measured quality factor value with the quality factor threshold to determine the presence or absence of a foreign object.

[0058] A wireless power transmitter according to another embodiment of the present invention includes a transmission antenna for transmitting wireless power, a demodulator for demodulating a signal of the transmission antenna to receive a foreign object detection status packet, and a controller for determining the presence or absence of a foreign object based on the demodulated foreign object detection status packet, and the controller can adjust the intensity of the wireless power based on the determination result regarding the presence or absence of the foreign object.

[0059] Further, if the controller determines that no foreign object exists, it maintains the guaranteed power at a second power which is the initial setting, and if the controller determines that a foreign object exists, it can downward adjust the guaranteed power from the second power to the first power.

[0060] ​​​​​​​​ Here, the first power may be 5 W or less.

[0061] Also, during charging with the adjusted intensity of the wireless power, the controller can additionally determine the presence or absence of a foreign object.

[0062] In one aspect, the controller determines the presence or absence of a foreign object based on the power loss estimated during charging, and if the determination result based on the power loss indicates the presence of a foreign object, the power transmission for charging can be interrupted.

[0063] Here, the wireless power transmitter further includes a sensor that transmits information regarding the intensity of the transmitted power to the controller, and the controller estimates the power loss based on the information regarding the intensity of the transmitted power and the information regarding the intensity of the received power received from the wireless power receiver corresponding to the transmitted power during charging, and can determine the presence or absence of a foreign object by comparing the estimated power loss with a preset power loss reference value.

[0064] In another aspect, the wireless power transmitter further includes a sensor that transmits information regarding the measured temperature to the controller, and the controller determines the presence or absence of a foreign object based on the temperature change calculated using the information regarding the measured temperature during charging, and if the determination result based on the temperature change indicates the presence of a foreign object, the power transmission for charging can be interrupted.

[0065] In still another aspect, the controller determines the presence or absence of a foreign object based on the power loss estimated during charging, and if the determination result based on the power loss indicates the presence of a foreign object, during charging ​​​​​​​​​​​​Based on the measured temperature change, determine the presence or absence of foreign matter, and based on the temperature change, if the determination result is that foreign matter is present, interrupt the power transmission for charging within a predetermined time. This is possible.

[0066] Also, if the additional determination result is that no foreign matter is present, the controller can renegotiate the power transmission contract with the corresponding wireless power receiver and reset the guaranteed power.

[0067] Further, according to the determination result of the controller regarding the presence or absence of the foreign matter, the controller transmits a response instructing that foreign matter is present, and if the currently set guaranteed power exceeds the first power, the power intensity can be downward adjusted to be equal to or less than the first power.

[0068] Still another embodiment of the present invention provides a computer-readable recording medium recording a program for executing any one of the wireless power transmission control methods.

[0069] The aspects of the present invention are only a part of the preferred embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood based on the following detailed description of the present invention detailed by those having ordinary knowledge in the technical field.

Advantages of the Invention

[0070] The effects of the method, apparatus, and system according to the present invention will be described as follows.

[0071] The present invention has the advantage of providing a wireless power transmission control method and apparatus for wireless charging.

[0072] Also, the present invention has the advantage of providing a wireless power transmitter capable of more accurately detecting foreign matter. There is.

[0073] In addition, the present invention has an advantage of providing a wireless power transmission control method and apparatus that can prevent unnecessary charging interruptions by minimizing foreign object detection errors. There is.

[0074] In addition, the present invention has an advantage of providing a wireless power transmitter that prevents damage to equipment caused by foreign objects and enables continuous charging through adaptive transmission power control based on the presence or absence of foreign objects. There is. There is.

[0075] In addition, the present invention has an advantage of being able to provide a wireless power transmitter that can stably transmit a wide range of wireless power depending on the type of receiver and the power transmission environment. There is.

[0076] The effects obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention pertains from the following description. There is. There is.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0096] A wireless power transmission control method of a wireless power transmitter according to an embodiment includes a first packet receiving step of receiving a foreign object detection state packet, a first determination step of determining the presence or absence of a foreign object based on the foreign object detection state packet, and a power control step of controlling power based on the determination result of the first determination step. The power control step includes, when it is determined in the first determination step that there is a foreign object and a first packet receiving step of receiving a foreign object detection state packet, and a first determination step of determining the presence or absence of a foreign object based on the foreign object detection state packet, and a power control step of controlling power based on the determination result of the first determination step. and a first determination step of determining the presence or absence of a foreign object based on the foreign object detection state packet, and a power control step of controlling power based on the determination result of the first determination step. The power control step includes, when it is determined in the first determination step that there is a foreign object and a power control step of controlling power based on the determination result of the first determination step. The power control step includes, when it is determined in the first determination step that there is a foreign object When there is no foreign object as determined in the first determination step, a first power transmission mode for transmitting the first power and a second power transmission mode for transmitting the second power when it is determined that there is no foreign object may be included.

[0097] Hereinafter, apparatuses and various methods to which embodiments of the present invention are applied will be described in more detail with reference to the drawings. The suffixes “module” and “unit” for components used in the following description are given or mixed for the sake of ease of specification writing only, and they do not have meanings or roles that are distinguished from each other by themselves.

[0098] Also, the suffixes “module” and “unit” for components used in the following description may be implemented by hardware components - for example, circuit elements, microprocessors, memories, sensors, etc. - but this is only one example, and part or all of the functions of the corresponding components may be implemented by software.

[0099] In the description of the embodiments, when it is described that something is formed “above or below” each component, “above or below” includes all cases where two components are in direct contact with each other or one or more other components are arranged between the two components. Also, when expressed as “above or below”, it may include the meaning not only in the upper direction but also in the lower direction with respect to one component.

[0100] In the description of the embodiments, a device equipped with a function of transmitting wireless power on a wireless charging system is, for the sake of convenience of explanation, a wireless power transmitter, a wireless power transmission device, a wireless power transmission device, ​​​​​​​​​​​​A radio power transmitter, a transmission stage, a transmitter, a transmission device, a transmission side, a wireless power transmission device, a wireless power transmitter, etc. will be used interchangeably. Also, as an expression for a device equipped with a function of receiving wireless power from a wireless power transmission device, for the sake of convenience of explanation, a wireless power receiving device, a wireless power receiver, a wireless power receiving device, a wireless power receiver, a receiving terminal device, a receiving side, a receiving device, a receiver, etc. may be used interchangeably. The transmitter according to the present invention may be configured in the form of a pad, a pedestal, an AP (Access Point), a small base station, a stand, a ceiling-embedded form, a wall-mounted form, etc., and one transmitter may transmit power to a plurality of wireless power receiving devices. For this purpose, the transmitter may include at least one wireless power transmission means. Here, the wireless power transmission means may use various wireless power transmission standards based on the electromagnetic induction method of charging using the principle of electromagnetic induction in which an electric field is generated by a power transmission stage coil and electricity is induced in the receiving stage coil by the influence of the magnetic field. As an example, the wireless power transmission standard may include, but is not limited to, the standard technology of the electromagnetic induction method defined by WPC (Wireless Power Consortium) Qi and PMA (Power Matters Alliance), which are wireless charging technology standard organizations. Also, the receiver according to an embodiment of the present invention may be provided with at least one wireless power receiving means and may receive wireless power from one or more transmitters. The receiver according to the present invention may be a mobile phone, a smartphone, etc.

[0101] The transmitter according to the present invention may be configured in the form of a pad, a pedestal, an AP (Access Point), a small base station, a stand, a ceiling-embedded form, a wall-mounted form, etc., and one transmitter may transmit power to a plurality of wireless power receiving devices. For this purpose, the transmitter may include at least one wireless power transmission means. Here, the wireless power transmission means may use various wireless power transmission standards based on the electromagnetic induction method of charging using the principle of electromagnetic induction in which an electric field is generated by a power transmission stage coil and electricity is induced in the receiving stage coil by the influence of the magnetic field. As an example, the wireless power transmission standard may include, but is not limited to, the standard technology of the electromagnetic induction method defined by WPC (Wireless Power Consortium) Qi and PMA (Power Matters Alliance), which are wireless charging technology standard organizations. Also, the receiver according to an embodiment of the present invention may be provided with at least one wireless power receiving means and may receive wireless power from one or more transmitters. The receiver according to the present invention may be a mobile phone, a smartphone, etc.

[0102] Here, the wireless power transmission means may use various wireless power transmission standards based on the electromagnetic induction method of charging using the principle of electromagnetic induction in which an electric field is generated by a power transmission stage coil and electricity is induced in the receiving stage coil by the influence of the magnetic field. As an example, the wireless power transmission standard may include, but is not limited to, the standard technology of the electromagnetic induction method defined by WPC (Wireless Power Consortium) Qi and PMA (Power Matters Alliance), which are wireless charging technology standard organizations. The transmitter according to the present invention may be configured in the form of a pad, a pedestal, an AP (Access Point), a small base station, a stand, a ceiling-embedded form, a wall-mounted form, etc., and one transmitter may transmit power to a plurality of wireless power receiving devices. For this purpose, the transmitter may include at least one wireless power transmission means. Also, the receiver according to an embodiment of the present invention may be provided with at least one wireless power receiving means and may receive wireless power from one or more transmitters. The receiver according to the present invention may be a mobile phone, a smartphone, etc. Here, the wireless power transmission means may use various wireless power transmission standards based on the electromagnetic induction method of charging using the principle of electromagnetic induction in which an electric field is generated by a power transmission stage coil and electricity is induced in the receiving stage coil by the influence of the magnetic field. As an example, the wireless power transmission standard may include, but is not limited to, the standard technology of the electromagnetic induction method defined by WPC (Wireless Power Consortium) Qi and PMA (Power Matters Alliance), which are wireless charging technology standard organizations. The transmitter according to the present invention may be configured in the form of a pad, a pedestal, an AP (Access Point), a small base station, a stand, a ceiling-embedded form, a wall-mounted form, etc., and one transmitter may transmit power to a plurality of wireless power receiving devices. For this purpose, the transmitter may include at least one wireless power transmission means.

[0103] Also, the receiver according to an embodiment of the present invention may be provided with at least one wireless power receiving means and may receive wireless power from one or more transmitters. The receiver according to the present invention may be a mobile phone, a smartphone, etc.

[0104] The receiver according to the present invention may be a mobile phone, a smartphone, etc. art phone), laptop computer , digital broadcast terminal, PDA (Personal Digital Assista nts), PMP (Portable Multimedia Player), navigation -tion, MP3 player, electric toothbrush, electronic tag, lighting device, remote control, float It can be used for small electronic devices such as wearable devices such as smart watches, but it is not limited to this, and any device equipped with the wireless power receiving means according to the present invention and capable of charging the battery is sufficient.

[0105] FIG. 1 is a block diagram for explaining a wireless charging system according to an embodiment of the present invention .

[0106] Referring to FIG. 1, the wireless charging system generally includes a wireless power transmission stage 1 0 that wirelessly transmits power, a wireless power reception stage 20 that receives the transmitted power, and an electronic device 30 that receives the supplied received power and may be configured.

[0107] As an example, the wireless power transmission stage 10 and the wireless power reception stage 20 perform in-band communication that exchanges information using the same frequency band as the operating frequency used for wireless power transmission and can be performed.

[0108] In in-band communication, when the power signal 41 transmitted by the wireless power transmission stage 10 is received by the wireless power reception stage 20, the wireless power reception stage 20 modulates the received power signal, and the modulated signal 42 can be transmitted to the wireless power transmission stage 10.

[0109] As another example, the wireless power transmission stage 10 and the wireless power reception stage 20 are used for wireless power transmission​ Out-of-band communication that exchanges information using a separate frequency band different from the operating frequency may be performed.

[0110] As an example, the information exchanged between the wireless power transmission stage 10 and the wireless power reception stage 20 may include not only mutual state information but also control information.

[0111] Here, the state information and control information exchanged between the transmission and reception stages will become clearer through the description of the embodiments described later.

[0112] The in-band communication and out-of-band communication can provide two-way communication, but are not limited thereto, and in other embodiments, one-way communication or half-duplex communication may be provided.

[0113] As an example, one-way communication may be such that the wireless power reception stage 20 transmits information only to the wireless power transmission stage 10, but is not limited thereto, and the wireless power transmission stage 10 may transmit information only to the wireless power reception stage 2 0.

[0114] The half-duplex communication method enables two-way communication between the wireless power reception stage 20 and the wireless power transmission stage 10, but has the characteristic that information can be transmitted only by one device at any one time.

[0115] The wireless power reception stage 20 according to an embodiment of the present invention may acquire various state information of the electronic device 30.

[0116] As an example, the state information of the electronic device 30 is current power consumption information, information for identifying the application being executed, CPU usage information, battery charge state information, battery output voltage ​​​​​​​​​It can include current information etc., but is not limited thereto, and can be obtained from the electronic device 30, and any information that can be utilized for the control of wireless power is acceptable.

[0117] In particular, the wireless power transmission stage 10 according to an embodiment of the present invention can transmit a specified packet indicating the presence or absence of high-speed charging support to the wireless power reception stage 20.

[0118] When it is confirmed that the connected wireless power transmission stage 10 supports the high-speed charging mode, the wireless power reception stage 20 can notify the electronic device 30 of this.

[0119] The electronic device 30 can display that high-speed charging is possible through the provided specified display means - for example, it can be a liquid crystal display.

[0120] FIG. 2 is a block diagram for explaining a wireless charging system according to another embodiment of the present invention.

[0121] As an example, as illustrated by reference numeral 200a in the drawing, the wireless power reception stage 20 can be composed of a plurality of wireless power reception devices, and a plurality of wireless power reception devices can be connected to one wireless power transmission stage 10 to perform wireless charging.

[0122] At this time, the wireless power transmission stage 10 can distribute and transmit power to a plurality of wireless power reception devices in a time-division manner, but is not limited thereto. As another example, the wireless power transmission stage 10 can distribute and transmit power to a plurality of wireless power reception devices by using different frequency bands assigned to each wireless power reception device.

[0123] At this time, the number of wireless power reception devices that can be connected to one wireless power transmission stage 10 is the wireless power Power demand per receiving device, battery charge state, power consumption of electronic devices, and wireless power transmission It can be adaptively determined based on at least one of the available power of the wireless power transmission device.

[0124] As another example, as shown by reference numeral 200b in the drawings, the wireless power transmission stage 10 may be composed of a plurality of wireless power transmission devices.

[0125] In this case, the wireless power reception stage 20 can be simultaneously connected to a plurality of wireless power transmission devices, and it may receive power simultaneously from the connected wireless power transmission devices to perform charging.

[0126] At this time, the number of wireless power transmission devices connected to the wireless power reception stage 20 is the required power of the wireless power reception stage 2 0, battery charge state, power consumption of electronic devices, available power of wireless power transmission devices, etc., and can be adaptively determined based on these.

[0127] FIG. 3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.

[0128] As an example, the wireless power transmitter may be equipped with three transmission coils 111, 112, and 113. Each transmission coil may partially overlap with different transmission coils, and the wireless power transmitter sequentially sends predetermined sensing signals 117, 127 - for example, digital pinging signals - for sensing the presence of the wireless power receiver through each transmission coil in a defined order.

[0129] As shown in FIG. 3, the wireless power transmitter sequentially sends the sensing signal 117 through the primary sensing signal transmission procedure illustrated by reference numeral 110 in the drawings, and the signal strength from the wireless power receiver 115 ​​​​The signal strength indicator (116) is received The transmission coils 111 and 112 can be identified.

[0130] Subsequently, the wireless power transmitter passes through the secondary sensing signal transmission procedure illustrated by drawing number 120 to sequentially transmit the sensing signal 127, and the transmission coil 111 where the signal strength indicator 126 is received , 112, among which the power transmission efficiency (or charging efficiency)-that is, the alignment state between the transmission coil and the reception coil -is good, is identified, and power can be transmitted through the identified transmission coil -that is, wireless charging can be performed- and controlled.

[0131] As shown in FIG. 3, the reason why the wireless power transmitter performs the two sensing signal transmission procedures is to more accurately identify which transmission coil the reception coil of the wireless power receiver is well-aligned with .

[0132] If, as shown by drawing numbers 110 and 120 in FIG. 3, signal strength indicators 116 and 126 are received by the first transmission coil 11 1 and the second transmission coil 112, the wireless power transmitter selects the most well-aligned transmission coil based on the signal strength indicators 126 received by the first transmission coil 111 and the second transmission coil 112 respectively, and performs wireless charging using the selected transmission coil .

[0133] FIG. 4 is a state transition diagram for explaining the wireless power transmission procedure according to an embodiment of the present invention .

[0134] Referring to FIG. 4, the transmission of power from the transmitter to the receiver according to an embodiment of the present invention is large Selection Phase (410), Ping Phase (420), Identification and Configuration Phase (430), Negotiation Phase (440), Calibration Phase (450), Power Transfer Phase (460), and Renegotiation Phase (470). can be divided into the following phases: During the Selection Phase 410, when starting or maintaining power transmission, it transitions when specific errors or specific events are detected - for example, including reference numerals S402, S404 , S408, S410, and S412.

[0135] Here, specific errors and specific events will become clear through the following description.

[0136]

[0137]

[0138] In addition, during the Selection Phase 410, the transmitter can monitor whether an object is present on the surface of the interface.

[0138] If the transmitter senses that an object has been placed on the surface of the interface, it can transition to the Ping Phase 420 (S403).

[0139] As an example, during the Selection Phase 410, the transmitter transmits a very short - pulse analog Ping signal and senses whether an object is present in the active area of the interface surface based on the current change in the transmission coil (or primary coil). Here, the active area is where the receiver is located (Primary Coil). on the surface of the interface. and may mean an area where wireless charging is possible.

[0140] As another example, at the selection stage 410, the transmitter may use the provided sensors to sense whether an object exists in the active area of the interface surface. .

[0141] As an example, the sensors can include Hall sensors, pressure sensors, capacitance sensors, current sensors, voltage sensors, light sensing sensors, etc., and at least one of these sensors can sense an object placed in the active area.

[0142] If an object is sensed at the selection stage 410, the wireless power transmitter can measure the quality factor corresponding to a provided LC resonance circuit - for example, the LC resonance circuit is composed of a coil (inductor) and a resonance capacitor connected in series - .

[0143] When an object is sensed at the selection stage 410, the transmitter according to an embodiment of the present invention can measure the quality factor (Quality F actor) value to determine whether a wireless power receiver is placed with a foreign object in the charging area.

[0144] Here, the quality factor value can be measured before entering the ping stage 420. Also, the quality factor value can be measured in a state where power transmission through the transmission coil is temporarily interrupted.

[0145] As an example, the quality factor value can be measured with respect to a predefined reference operating frequency.

[0146] As another example, the quality factor value is a constant frequency within the operating frequency band used for wireless power transmission. It may be measured by sampling in number units.

[0147] The transmitter according to an embodiment of the present invention confirms the frequency value corresponding to the quality factor value having the maximum value among the quality factor values measured within the operating frequency band, and can store this in the memory. For the convenience of the following explanation, the frequency at which the quality factor value within the operating frequency band is the maximum is referred to as the quality factor peak frequency (Quality Factor Peak Frequency) or simply named the peak frequency for the convenience of explanation.

[0148] The distribution of the quality factor values measured corresponding to the operating frequency band and the quality factor peak frequency may vary depending on the type of the wireless power transmitter.

[0149] In particular, the quality factor values measured using a transmitter - hereinafter named "authentication transmitter" for the convenience of explanation - and an LCR meter to authenticate a receiver for the same operating frequency may be different from the quality factor values measured by a commercial transmitter.

[0150] When the wireless power transmitter receives a signal strength packet in the ping stage 420, it can enter the identification and configuration stage 430 (S403).

[0151] When the identification and configuration procedure of the wireless power transmitter is completed normally, it can enter the negotiation stage 440 (S405).

[0152] Also, when the identification and configuration procedure of the wireless power transmitter is completed normally, it may enter the power transmission stage 460 according to the type of the receiver (S406).

[0153] ​​​​​​​​When the wireless power transmitter enters negotiation stage 440, it can receive a foreign object detection status packet containing a reference quality factor value from the wireless power receiver. including a foreign object detection status packet.

[0154] The wireless power transmitter can determine a quality factor threshold based on the received reference quality factor value. It can do so.

[0155] After that, the wireless power transmitter can compare the measured quality factor value with the quality factor threshold to determine the presence or absence of a foreign object. It can make such a determination.

[0156] However, when a foreign object detection method that simply compares the predetermined quality factor threshold determined based on the reference quality factor value with the measured quality factor value to detect the presence or absence of a foreign object is applied to a commercial transmitter, the accuracy for foreign object detection may be low. In this case, the accuracy for foreign object detection may decrease. Here, the reference quality factor value means the quality factor value at the reference operating frequency measured in a state where no foreign object is placed in the charging area of the authentication transmitter.

[0157] The reference quality factor value measured at negotiation stage 440 is compared with the quality factor value corresponding to the reference operating frequency measured before ping stage 420 - hereinafter named the current quality factor value for convenience of explanation - to determine the presence or absence of a foreign object. It can be used to make such a determination.

[0158] However, the transmitter at which the reference quality factor value is measured - that is, the authentication transmitter - and the transmitter at which the current quality factor value is measured may be different from each other. Therefore, the determined quality factor threshold for determining the presence or absence of a foreign object may not be accurate. It may not be accurate. It can be used to make such a determination.

[0159] However, the transmitter at which the reference quality factor value is measured - that is, the authentication transmitter - and the transmitter at which the current quality factor value is measured may be different from each other. Therefore, the determined quality factor threshold for determining the presence or absence of a foreign object may not be accurate. It may not be accurate. Therefore, the determined quality factor threshold for determining the presence or absence of a foreign object may not be accurate.

[0160] Therefore, the transmitter according to an embodiment of the present invention is a reference product corresponding to the type of the corresponding transmitter receives the quality factor value from the wireless power receiver, and may determine the quality factor critical value based on the received reference quality factor value threshold value.

[0161] The transmission coil may have its inductance and / or the series resistance component within the corresponding transmission coil decreased due to changes in the surrounding environment, whereby the resonant frequency of the corresponding transmission coil may be changed (shifted). That is, the quality factor peak frequency, which is the frequency at which the maximum quality factor value within the operating frequency band is measured, may be shifted moved.

[0162] As an example, since the wireless power receiver includes a magnetic shield (shielding material) having a high magnetic permeability, the high magnetic permeability can increase the inductance value measured by the transmission coil able. On the contrary, foreign objects of the metal type can decrease the inductance value able.

[0163] Generally, in the case of an LC resonance circuit, the resonance frequency (f_resonant) is

Equation

[0164] When only the wireless power receiver is placed in the charging area of the transmitter, the L value increases, so the resonance frequency number becomes smaller. That is, the resonance frequency will shift to the left on the frequency axis shift.

[0165] On the contrary, when a foreign object is placed in the charging area of the transmitter, the L value decreases, so the resonance frequency becomes large become. That is, the resonance frequency will shift to the right on the frequency axis

[0166] ​A transmitter according to another embodiment of the present invention may determine the presence or absence of a foreign object placed in a charging area based on a change in the quality factor peak frequency.

[0167] The transmitter can obtain information regarding a quality factor peak frequency - hereinafter, for convenience of explanation, referred to as "reference quality factor peak frequency (pf_reference)" or "reference peak frequency" - from the receiver or can maintain it in a predetermined recording area in advance.

[0168] When the transmitter senses that an object is placed in the charging area, before entering the ping stage 420 it measures the quality factor value within the operating frequency band and can identify the quality factor peak frequency based on the measurement result. Here, in order to distinguish the identified quality factor peak frequency from the reference quality factor peak frequency, it is named "measured quality factor peak frequency (pf_measured)" or "measured peak frequency".

[0169] In the negotiation stage 430, the transmitter may determine the presence or absence of a foreign object based on the reference quality factor peak frequency and the measured quality factor peak frequency.

[0170] If information regarding the reference quality factor peak frequency is received from the receiver, it can be received through a predetermined packet in the identification and configuration stage 430 or the negotiation stage 440.

[0171] As an example, in the identification and configuration stage 430, the transmitter can transmit information regarding the type of its own transmitter to the receiver. The receiver reads out the reference quality factor peak frequency stored in advance corresponding to the received transmitter type information from the corresponding memory, and the read ​​​​​​​Information regarding the reference quality factor peak frequency can be transmitted to the transmitter.

[0172] A transmitter according to still another embodiment of the present invention uses all of a foreign object detection method based on the quality factor peak frequency and a foreign object detection method based on the quality factor value to determine the presence or absence of a foreign object. For example, when comparing the reference quality factor value corresponding to the type of the transmitter with the measured quality factor value and there is no significant difference - for example, when the difference between the two values is 10% or less - the reference quality factor peak frequency corresponding to the type of the transmitter and the measured quality factor peak frequency may be compared to determine the presence or absence of a foreign object. On the contrary, when the difference between the two quality factor values exceeds 10%, the transmitter can immediately determine that a foreign object is present. In another example, when the comparison result between the quality factor threshold value determined based on the reference quality factor value corresponding to the type of the transmitter and the measured quality factor value indicates that there is no foreign object, the transmitter may compare the reference quality factor peak frequency corresponding to the type of the transmitter with the measured quality factor peak frequency to determine the presence or absence of a foreign object. When it is not easy for the transmitter to detect a foreign object based on the quality factor value, the transmitter may request the identified receiver for information regarding the reference quality factor peak frequency corresponding to the type of the transmitter. After that, when the transmitter receives information regarding the reference quality factor peak frequency from the receiver, the transmitter can use the reference quality factor peak frequency and the measured quality factor peak frequency to determine the presence or absence of a foreign object. Through this, the transmitter can more accurately detect a foreign object placed in the charging area.

[0173]

[0174]

[0175] When the transmitter senses an object, it enters the ping stage 420 to activate (Wake up) the receiver and can transmit a digital ping (Digital Ping) to identify whether the sensed object is a wireless power receiver.

[0176] If the transmitter does not receive a response signal to the digital ping - for example, a signal strength packet - from the receiver at the ping stage 420, it can transition back to the selection stage 410.

[0177] Also, if the transmitter receives a signal - that is, a charge - complete packet - from the receiver at the ping stage 420 indicating that the power transmission is complete, it may transition to the selection stage 410. When the ping stage 420 is complete, the transmitter can transition to the identification and configuration stage 430 to identify the receiver and collect receiver configuration and status information.

[0178] The transmitter may transmit information about the type of the transmitter to the receiver at the identification and configuration stage 430. The receiver may request information about the type of the transmitter from the transmitter at the identification and configuration stage 430, and the transmitter may transmit information about the type of the transmitter to the receiver in response to the receiver's request.

[0179] Also, at the identification and configuration stage 430, the transmitter may receive an unexpected packet, or no desired packet may be received within a predefined time (time out), or there may be a packet transmission error (transmission error), or no power transmission contract may be set (no power t or).

[0180] The receiver may request information about the type of the transmitter from the transmitter at the identification and configuration stage 430, and the transmitter may transmit information about the type of the transmitter to the receiver in response to the receiver's request. The receiver may request information about the type of the transmitter from the transmitter at the identification and configuration stage 430, and the transmitter may transmit information about the type of the transmitter to the receiver in response to the receiver's request. or.

[0181] Also, at the identification and configuration stage 430, the transmitter may receive an unexpected packet (un expected packet), or no desired packet may be received within a predefined time (time out), or there may be a packet transmission error (transm ission error), or no power transmission contract may be set (no power t ission error), or no power transmission contract may be set (no power t It can transition to the selection stage 410 of the transfer contract).

[0182] The transmitter can check whether it is necessary to enter the negotiation stage 440 based on the negotiation field value of the configuration packet (Configuration packet) received in the identification and configuration stage 430. ion packet) Based on this, it can be determined whether it is necessary to enter the negotiation stage 440.

[0183] If the confirmation result indicates that negotiation is necessary, the transmitter can enter the negotiation stage 440 and perform the subsequent steps of the predetermined FOD detection procedure. Continue to execute.

[0184] On the contrary, if the confirmation result indicates that negotiation is not necessary, the transmitter can immediately enter the power transmission stage 460. It may be.

[0185] If it is confirmed in the identification and configuration stage 430 that the corresponding wireless power receiver only supports the first power transmission mode, the wireless power transmitter according to an embodiment can enter the power transmission stage 460 immediately without performing the negotiation stage 440. 1 power transmission mode only, the negotiation stage 440 can be skipped and the power transmission stage 460 can be entered immediately. After entering the power transmission stage 460, the wireless power transmitter can periodically perform a predetermined foreign object detection procedure.

[0186] Here, the foreign object detection procedure may be a foreign object detection procedure based on the quality factor value, but is not limited thereto, and a foreign object detection procedure based on power loss may be applied. It can be executed.

[0187] The foreign object detection procedure based on power loss is a method of determining the presence or absence of a foreign object by comparing the difference between the transmission power of the wireless power transmitter and the received power of the wireless power receiver with a predetermined reference value. For details of the procedure It is not limited to this, and a foreign object detection procedure based on power loss may be applied. It can be applied.

[0188] The foreign object detection procedure based on power loss is a method of determining the presence or absence of a foreign object by comparing the difference between the transmission power of the wireless power transmitter and the received power of the wireless power receiver with a predetermined reference value. Specifically The radio power of the receiver is compared with a predetermined reference value to determine the presence or absence of a foreign object. For detailed procedures The continuation will become clearer through the description of the drawings to be described later.

[0189] As an example, at the negotiation stage 440, the transmitter can receive a foreign object detection status packet (FOD (Foreign Object Detection) Status Packet) containing a reference quality factor value. Or it can receive an FOD Status Packet containing a reference peak frequency value corresponding to the type of the transmitter. packet) Or it can receive an FOD Status Packet containing a reference peak frequency value corresponding to the type of the transmitter. packet)

[0190] As another example, at the negotiation stage 440, the transmitter may receive a status packet containing a reference quality factor value and a reference peak frequency value corresponding to the type of the transmitter. At this time, the transmitter can determine a quality factor threshold for foreign object detection based on the reference quality factor value corresponding to the type of the transmitter. And a reference peak frequency value corresponding to the type of the transmitter. At this time, the transmitter can determine a quality factor threshold for foreign object detection based on the reference quality factor value corresponding to the type of the transmitter. And a reference peak frequency value corresponding to the type of the transmitter. At this time, the transmitter can determine a quality factor threshold for foreign object detection based on the reference quality factor value corresponding to the type of the transmitter. determine.

[0191] The transmitter may determine a quality factor peak frequency threshold for foreign object detection based on the reference quality factor peak frequency value corresponding to the type of the transmitter. determine.

[0192] The transmitter can compare the determined quality factor threshold and / or the determined quality factor peak frequency threshold with the measured quality factor value - meaning the quality factor value measured before the ping stage 420 - and / or the measured quality factor peak frequency value to detect foreign objects placed in the charging area. - and / or the measured quality factor peak frequency value to detect foreign objects placed in the charging area. - and / or the measured quality factor peak frequency value to detect foreign objects placed in the charging area. detect.

[0193] The transmitter can control power transmission based on the foreign object detection result. As an example, when a foreign object is detected, the transmitter transmits a negative acknowledge packet to the receiver as a response to the foreign object detection status packet. When a foreign object is detected, the transmitter transmits a negative acknowledge packet to the receiver as a response to the foreign object detection status packet. packet) This can be done. Along with this, power transmission can be interrupted, but is not limited thereto.

[0194] The transmitter can detect foreign objects placed in the charging area by comparing the determined quality factor peak frequency threshold value and the measured quality factor peak frequency value. The transmitter can control power transmission according to the foreign object detection result. As an example, when a foreign object is detected, the transmitter can transmit a NACK packet (Negative acknowledge packet) to the receiver as a response to the foreign object detection status packet (FOD Status Packet). Along with this, power transmission can be interrupted, but is not limited thereto. packet (Negative acknowledge packet) to the receiver. This can be done. Along with this, power transmission can be interrupted, but is not limited thereto.

[0195] When a foreign object is detected, the transmitter can receive an end of charge message (End of Ch arge Message) from the receiver, and thereby enter the selection step 410. This can be done.

[0196] When a foreign object is detected during the negotiation step 440 by the transmitter according to another embodiment of the present invention, the transmitter may enter the power transmission step 460 (S415). This can be done.

[0197] On the contrary, when no foreign object is detected, the transmitter may complete the negotiation step 440 for the transmission power, and enter the power transmission step 460 through the correction step 450 (S407 and S409). This can be done.

[0198] Specifically, when no foreign object is detected, when the transmitter enters the correction step 450, it determines the intensity of the power received in the reception stage, and measures the power loss between the transmission stage and the reception stage in order to determine the intensity of the power to be transmitted in the transmission stage. This can be done. This can be done.

[0199] As an example, the transmitter can determine the intensity of the received power to the receiver based on the intensity information of the received power fed back from the receiving stage during power transmission. That is, the transmitter can predict (or calculate) the power loss based on the intensity difference between the transmission power at the transmission stage and the received power at the receiving stage in the correction stage 450. In the power transmission stage 460, the transmitter can enter the selection stage 410 (S410) when an unexpected packet is received, the desired packet is not received within a predefined time (time out), a violation of the preset power transmission contract occurs (power transfer contract violation), or the charging is completed. Also, in the power transmission stage 460, when the transmitter needs to reconfigure the power transmission contract due to a change in the state of the transmitter or the like, it can transition to the renegotiation stage 470 (S411). At this time, when the renegotiation is successfully completed, the transmitter can return to the power transmission stage 460 (S413). The above-mentioned power transmission contract can be set based on the state and characteristic information of the transmitter and the receiver. As an example, the transmitter state information can include information on the maximum transmissible power, information on the number of the maximum receivable receivers, etc., and the receiver state information can include information on the required power.

[0200] The wireless power transmitter according to the embodiment of the present invention operates in any one of the second power transmission modes among the first power transmission modes based on the guaranteed power required by the wireless power receiver.

[0201]

[0202]

[0203] ​​​​​​​​​​​​​​ It can operate in mode D.

[0204] The wireless power transmitter according to another embodiment of the present invention can operate in any one of the operation modes of the second power transmission mode among the first power transmission modes based on the determination result regarding the presence or absence of a foreign object. It can operate.

[0205] The wireless power receiver connected to the wireless power transmitter can be a receiver that supports only the first power transmission mode or a receiver that supports both the first power transmission mode and the second power transmission mode. .

[0206] Here, the guaranteed power that can be set corresponding to the second power transmission mode may be greater than the guaranteed power that can be set in the first power transmission mode.

[0207] As an example, the guaranteed power that can be set in the first power transmission mode is the first power - for example, 5W or 5W or less - and the guaranteed power that can be set in the second power transmission mode is greater than the first power and may be less than the second power - for example, 15W.

[0208] FIG. 5 is a flowchart for explaining a foreign object detection procedure in a wireless power transmission system according to an embodiment of the present invention.

[0209] Specifically, FIG. 5 is a drawing for explaining a foreign object detection procedure in the second power transmission mode. .

[0210] Referring to FIG. 5, when an object is sensed at the selection stage, the wireless power transmitter 510 can measure the quality factor value at a predetermined reference operating frequency before entering the ping stage (S501). . Here, the reference operating frequency is the resonance frequency. It is possible, but not limited to this. The wireless power transmitter 510 can store the measured quality factor value in the internal memory (S502).

[0211] The wireless power transmitter 510 can enter the ping stage and perform the sensing signal transmission procedure described in FIG. 3 (S503).

[0212] When the wireless power receiver 520 is sensed, the wireless power transmitter 510 can enter the identification and configuration stage and receive the identification packet and the configuration packet (S504 and S5 05).

[0213] The wireless power transmitter 510 can enter the negotiation stage and receive the foreign object detection status packet from the wireless power receiver 5 20 (S506). Here, the foreign object detection status packet can include the reference quality factor value.

[0214] The wireless power receiver 510 can determine a threshold value for determining the presence or absence of a foreign object based on the reference quality factor value included in the foreign object detection status packet (S507).

[0215] As an example, the threshold value can be determined to be a value that is smaller than the reference quality factor value by a predetermined ratio.

[0216] The wireless power transmitter 510 can compare the measured quality factor value with the determined threshold value to detect a foreign object (S508). Here, if the measured quality factor value is smaller than the threshold value , the wireless power transmitter 510 can determine that there is a foreign object in the charging area.

[0217] The wireless power transmitter 510 can send an ACK response or a NACK response or an ND ​​(No Decision) The response can be transmitted to the wireless power receiver 520 (S5 09).

[0218] When the wireless power receiver 520 receives a NACK response or an ND response from the wireless power transmitter 510 until the power transmission by the wireless power transmitter 510 is completely interrupted, it can control so that power of a certain intensity or more is not supplied to the electronic device (or battery / load) through its output terminal

[0219] Here, the power of a certain intensity or more may be based on 5W, but is not limited thereto, and may be differently defined by the design of those skilled in the art and the electronic device equipped with the wireless power receiver 510 and (or the battery / load connected to the wireless power receiver 510).

[0220] FIG. 6 is a block diagram for explaining the structure of a wireless power transmission device according to an embodiment of the present invention

[0221] Referring to FIG. 6, the wireless power transmission device 600 may include a controller 610, a gate driver (Gate Driver, 620), an inverter (Invertor, 630), a transmission antenna 640, a power source 650, a power supply (Power Supply, 660), a sensor 670 and a demodulator 680.

[0222] The power supply 660 can convert the DC power or AC power applied from the power source 650 and provide it to the inverter 630. Hereinafter, for convenience of explanation, the voltage supplied from the power supply 660 to the inverter 630 will be named the inverter input voltage or the V rail (V_r ail).

[0223]

[0223] ​​​​​​ The power supply 660 may be configured to include at least one of an AC / DC converter (AC / DC Converter) and a DC / DC converter (DC / DC Conve rter) depending on the type of power applied from the power source 650.

[0224] As an example, the power supply 660 may be a Switching Mode Power Supply (SMPS), and may use a switching control method such as a switching transistor , a filter, and a rectifier to convert an AC power source into a DC power source. Here, the rectifier and the filter may be independently configured and disposed between the AC power source and the SMPS.

[0225] The SMPS is a power supply device that controls the on / off time ratio of semiconductor switch elements to supply a DC power source with a stabilized output to the corresponding device or circuit element, and is widely used in many electronic devices and equipment because of its high efficiency, small size, and light weight.

[0226] In many cases, the stability and precision of the operation of an electronic circuit are affected by the quality of the power supply. Generally, the methods for stably converting and supplying power from a battery and a commercial AC power source are broadly classified into a series regulator method and a switched mode method.

[0227] The series regulator method used in TV receivers, CRT monitors, etc. has the disadvantages of simple peripheral circuits and low cost, but generates a lot of heat, has low power efficiency, and is large in volume.

[0228] ​​​​​On the one hand, the switching mode method has the advantages of almost no heat generation, high power efficiency, and small volume. On the other hand, it has the disadvantages of high price, complex circuit, and possible output noise and electromagnetic wave interference caused by high-frequency switching. For another example, the power supply 660 may use a variable SMPS (Variable Switching Mode Power Supply). The variable SMPS switches and rectifies the AC voltage in the tens of Hz band output from an AC power supply (AC Power Supply) to generate a DC voltage. The variable SMPS (Variable SMPS) may output a constant level of DC voltage or adjust the output level of the DC voltage according to a predetermined control of a transmission controller (Tx Controller). The variable SMPS can control the supply voltage according to the output power level of the power amplifier - that is, the inverter 530 - so that the power amplifier can always operate in a highly efficient saturation region and maintain maximum efficiency at all output levels.

[0229] On the one hand, the switching mode method has the advantages of almost no heat generation, high power efficiency, and small volume. On the other hand, it has the disadvantages of high price, complex circuit, and possible output noise and electromagnetic wave interference caused by high-frequency switching. For another example, the power supply 660 may use a variable SMPS (Variable Switching Mode Power Supply). The variable SMPS switches and rectifies the AC voltage in the tens of Hz band output from an AC power supply (AC Power Supply) to generate a DC voltage. (AC Power Supply) from the output of the dozens of Hz band of the AC voltage switching And rectify to generate a DC voltage.

[0230] The variable SMPS (Variable SMPS) may output a constant level of DC voltage or adjust the output level of the DC voltage according to a predetermined control of a transmission controller (Tx Controller). The variable SMPS can control the supply voltage according to the output power level of the power amplifier - that is, the inverter 530 - so that the power amplifier can always operate in a highly efficient saturation region and maintain maximum efficiency at all output levels. (Tx Controller) of a predetermined control of the DC voltage output level It may be adjusted. The variable SMPS can make the power amplifier of the wireless power transmitter always operate in a highly efficient saturation region So that, according to the output power level of the power amplifier - that is, the inverter 530 - the supply voltage is controlled to maintain maximum efficiency at all output levels. It can be done.

[0231] When using a commercial SMPS commonly used instead of the variable SMPS, a variable DC / DC converter (Variable DC / DC) can be used. The commercial SMPS And the variable DC / DC converter can control the supply voltage according to the output power level of the power amplifier so that the power amplifier can operate in a highly efficient saturation region and maintain maximum efficiency at all output levels. In one embodiment, the power amplifier may be of Class E type, but is not limited thereto. In one embodiment, the power amplifier may be of Class E type, but is not limited thereto. It may be used, but is not limited thereto.

[0232] ​ The inverter 630 can generate AC power transmitted wirelessly by converting a DC voltage (V_rail) at a certain level into an AC voltage by means of a switching pulse signal in the range of several MHz to several tens of MHz received through the gate driver 620 - that is, a Pulse Width Modulated (PWM) signal.

[0233] At this time, the gate driver 620 can generate a plurality of PWM signals SC_0 to SC_N for controlling a plurality of switches included in the inverter 630 by using the reference clock Ref_CLK signal supplied from the controller 610.

[0234] Here, when the inverter 630 includes a half - bridge circuit, N is 1, and when the inverter 630 includes a full - bridge circuit, N can be 3, but is not limited thereto. Depending on the design form of the inverter 630, different numbers of PWM signals may be supplied according to the type of inverter.

[0235] For example, in the embodiment of FIG. 6, when the inverter 630 includes a full - bridge circuit with 4 switches, the inverter 630 can receive 4 PWM signals SC_0, SC_1, SC_2, SC_3 from the gate driver 620 for controlling each switch.

[0236] On the contrary, in the embodiment of FIG. 6, when the inverter 630 includes a half - bridge circuit with 2 switches, the inverter 630 can receive 2 PWM signals SC_0, SC_1 from the gate driver 620 for controlling each switch.

[0237] ​​​​​​​​​​​​​The transmission antenna 640 wirelessly transmits the AC power signal received from the inverter 630. It may include at least one power transmission antenna (not shown) - for example, an LC resonance circuit - and also a matching circuit (not shown) for impedance matching. It can be configured to include these.

[0238] Also, when the transmission antenna 640 is provided with a plurality of transmission coils, the transmission antenna 640 may further include a coil selection circuit (not shown) for selecting the transmission coil used for wireless power transmission among the plurality of transmission coils. It may further include a coil selection circuit (not shown).

[0239] The sensor 670 measures the intensity of power / voltage / current input from the inverter 630 or (and) the intensity of power / voltage / current flowing through the transmission coil provided in the transmission antenna 640, and can include various sensing circuits for measuring the temperature and (or) temperature change at a specific position inside the wireless power transmitter - for example, including the transmission coil, the charging bed, the control circuit board, etc. Here, the information sensed by the sensor 670 can be transmitted to the controller 610. It can include various sensing circuits for measuring the temperature and (or) temperature change at a specific position inside the wireless power transmitter - for example, including the transmission coil, the charging bed, the control circuit board, etc. Here, the information sensed by the sensor 670 can be transmitted to the controller 610. It can be transmitted to the controller 610.

[0240] Also, the sensor 670 can measure the intensity of the current flowing through the transmission coil while the analog ping is being transmitted in the selection stages 410 and 510 and transmit it to the controller 610. The controller 610 compares the intensity information of the power flowing through the transmission coil with a predetermined reference value in the selection stage and can sense the presence or absence of an object placed in the charging area. compares the intensity information of the power flowing through the transmission coil with a predetermined reference value in the selection stage and can sense the presence or absence of an object placed in the charging area. It can sense the presence or absence of an object placed in the charging area.

[0241] When the wireless power transmitter 600 performs in-band communication with the wireless power receiver, the wireless power transmitter 600 can include a demodulator 680 connected to the transmission antenna 640.

[0242] The demodulator 680 can demodulate the amplitude-modulated in-band signal and transmit it to the controller 610. It can be done.

[0243] As an example, based on the demodulated signal received from the demodulator 680, the controller 610 can confirm the presence or absence of the reception of a signal strength indicator corresponding to the transmitted digital ping. The demodulator 680 can demodulate the amplitude-modulated in-band signal and transmit it to the controller 610. It can be done.

[0244] When the controller 610 senses an object placed in the charging area in the selection stage 410, it can enter the ping stage 420 and control the transmission of a digital ping through the transmission antenna 640. It can be controlled so that a digital ping is transmitted through the transmission antenna 640 when entering the ping stage 420. It can be done.

[0245] When the controller 610 senses an object placed in the charging area in the selection stage 410, it can temporarily interrupt the power transmission and measure the quality factor value before entering the ping stage. Here, the measured quality factor value can be maintained in a predetermined memory (not shown) provided in the wireless power transmitter 600. It can be measured before entering the ping stage. The measured quality factor value can be maintained in a predetermined memory (not shown) provided in the wireless power transmitter 600. It can be maintained.

[0246] When the controller 610 confirms the reception of the signal strength indicator in the ping stage, it can interrupt the digital ping transmission and enter the identification and configuration stage 430 to receive the identification packet and the configuration packet. It can enter the identification and configuration stage 430 to receive the identification packet and the configuration packet. It can be done.

[0247] When the controller 610 receives a power transmission end packet after entering the power transmission stage 460, it can interrupt the power transmission and enter the selection stage 410. It can interrupt the power transmission and enter the selection stage 410.

[0248] Also, when there is a foreign object in the charging area, the controller 610 may interrupt the power transmission and enter the selection stage 410. It may enter the selection stage 410.

[0249] In one embodiment, the controller 610 can calculate (or estimate) the power loss on the wireless power transmission path based on the received signal strength packet received from the wireless power receiver. The controller 610 may determine the presence or absence of foreign matter based on the calculated (or estimated) power loss.

[0250] In another embodiment, the controller 610 can measure the temperature change based on the temperature sensing information received from the sensor 670 or the temperature measurement information received from the wireless power receiver. The controller 610 may determine the presence or absence of foreign matter based on the measured temperature change.

[0251] In yet another embodiment, the controller 610 estimates the power loss and may perform the procedure of determining the presence or absence of foreign matter based on the temperature change according to the determination result of the presence or absence of foreign matter based on the estimated power loss.

[0252] In yet another embodiment, the controller 610 may perform the procedure of determining the presence or absence of foreign matter based on the power loss according to the determination result of the presence or absence of foreign matter based on the temperature change.

[0253] Also, when the controller 610 according to the present invention receives the FOD status packet in the negotiation stage 440, it determines a threshold value for foreign object detection based on the received FOD status packet, and may determine the presence or absence of foreign matter based on the determined threshold value.

[0254] Here, the FOD status packet may include at least one of a reference quality factor value, a resonance frequency, and a quality factor value at the resonance frequency.

[0255] ​​​​​​​​​​​When the controller 610 receives a power transmission end packet including a ripping code or a thermal code through the demodulator 680 in the power transmission stage 460, it may interrupt the power transmission and enter the selection stage 410 to drive the ripping timer. When the controller 610 receives a power transmission end packet including a ripping code or a thermal code through the demodulator 680 in the power transmission stage 460, it may interrupt the power transmission and enter the selection stage 410 to drive the ripping timer. For example, the guaranteed power in the first power transmission mode is 5W or less, which is named the first power.

[0256] The controller 610 can suppress the transmission of analog pinging and the output of the beep signal until the driven ripping timer expires. After that, when the ripping timer expires, the controller 610 can enter the pinging stage 420 and control the transmission of digital pinging through the transmission antenna 640. After that, when the ripping timer expires, the controller 610 can enter the pinging stage 420 and control the transmission of digital pinging through the transmission antenna 640. After that, when the ripping timer expires, the controller 610 can enter the pinging stage 420 and control the transmission of digital pinging through the transmission antenna 640.

[0257] After the controller 610 completes the identification and configuration of the sensed receiver, when it receives a power transmission end packet including a ripping code or a thermal code, it can reset the ripping time and then return to the selection stage 410. After the controller 610 completes the identification and configuration of the sensed receiver, when it receives a power transmission end packet including a ripping code or a thermal code, it can reset the ripping time and then return to the selection stage 410. After the controller 610 completes the identification and configuration of the sensed receiver, when it receives a power transmission end packet including a ripping code or a thermal code, it can reset the ripping time and then return to the selection stage 410.

[0258] The operation modes of the wireless power transmitter 600 according to the embodiments of the present invention may include a first power transmission mode and a second power transmission mode. The operation modes of the wireless power transmitter 600 according to the embodiments of the present invention may include a first power transmission mode and a second power transmission mode.

[0259] Based on the judgment result of the presence or absence of foreign objects in the negotiation stage 440, the controller 610 can operate in either the first power transmission mode or the second power transmission mode. Based on the judgment result of the presence or absence of foreign objects in the negotiation stage 440, the controller 610 can operate in either the first power transmission mode or the second power transmission mode. Based on the judgment result of the presence or absence of foreign objects in the negotiation stage 440, the controller 610 can operate in either the first power transmission mode or the second power transmission mode.

[0260] Here, the guaranteed power in the second power transmission mode may be greater than the guaranteed power (or the maximum transmission power) in the first power transmission mode. Here, the guaranteed power in the second power transmission mode may be greater than the guaranteed power (or the maximum transmission power) in the first power transmission mode.

[0261] For example, the guaranteed power in the first power transmission mode is 5W or less, which is named the first power. Yes, the guaranteed power in the second power transmission mode can be 15 W or less and is named the second power. It can be.

[0262] As another example, the guaranteed power in the first power transmission mode is 5 W, and the guaranteed power in the second power transmission mode can be a value between the first power and the second power, but is not limited thereto. It should be noted that the guaranteed power corresponding to each operation mode may be set differently according to the design of those skilled in the art. However, it is not limited thereto, and the guaranteed power corresponding to each operation mode may be set differently according to the design of those skilled in the art. It should be noted that the guaranteed power corresponding to each operation mode may be set differently according to the design of those skilled in the art. This must be noted.

[0263] If the determination result regarding the presence or absence of a foreign object in negotiation stage 440 is that a foreign object is present, the controller 610 can change the level of the guaranteed power from the second level corresponding to the second power transmission mode to the first level corresponding to the first power transmission mode. That is, when it is determined that a foreign object is present in negotiation stage 440, the controller 610 can adjust the guaranteed power downward. Through this, it is possible to prevent the device from being damaged by overheating due to a foreign object during high-power transmission. It can be changed to the first level corresponding to the first power transmission mode.

[0264] That is, when it is determined that a foreign object is present in negotiation stage 440, the controller 610 can adjust the guaranteed power downward. Through this, it is possible to prevent the device from being damaged by overheating due to a foreign object during high-power transmission. It can be prevented in advance.

[0265] When the controller 610 enters the first power transmission mode, it can control so that the correction stage 450 in FIG. 4 is not executed. It can be controlled so that it is not executed.

[0266] If the correction stage 450 is executed in the first power transmission mode even though a foreign object is present in the charging area, there is a problem that the accuracy of the foreign object detection method based on the power loss decreases. There is a problem that the accuracy drops.

[0267] Generally, the correction stage 450 is a procedure executed under the assumption that no foreign object is present. Therefore, when the correction stage 450 is executed even though a foreign object is present in the charging area, the power The foreign object detection method based on power loss has a problem that its accuracy is low and it is not reliable.

[0268] If, after entering the first power transmission mode, no foreign object is detected through the foreign object detection method based on the power loss and ( or) the foreign object detection method based on the temperature change, the controller 610 can enter the renegotiation stage 470 of FIG. 4.

[0269] When the power transmission contract is determined according to the renegotiation result with the wireless power receiver, the controller 610 may change the operation mode according to the determined power transmission contract.

[0270] As an example, the power transmission contract can include guaranteed power, and the controller 610 can change and set the guaranteed power through the renegotiation procedure with the wireless power receiver.

[0271] If the guaranteed power required by the wireless power receiver as a result of the renegotiation is changed from the first guaranteed power corresponding to the first power transmission mode to the second guaranteed power corresponding to the second power transmission mode when, the controller 610 may also switch the operation mode from the first power transmission mode to the second power transmission mode. As described in the above embodiments, the wireless power transmitter 600 according to the present invention can continuously charge even when it is determined that a foreign object exists, although there is actually no foreign object.

[0272] Specifically, when the wireless power transmitter 600 is operating in the initial second power transmission mode and it is determined that a foreign object exists although there is actually no foreign object, the charging is not immediately interrupted, and the power transmission mode is switched from the second power transmission mode to the first power transmission mode for charging.

[0273] ​​​​​​can be maintained.

[0274] As an example, even when the wireless power receiver is disposed in the charging area without foreign matter, due to the alignment state between the transmission coil and the reception coil, it may be determined that there is foreign matter in the charging area. It may be determined that there is foreign matter in the charging area.

[0275] The wireless power transmitter 600 according to the present invention has an advantage that foreign matter can be detected more accurately by performing an additional foreign matter detection procedure even after conversion to the first power transmission mode. Here, the additional foreign matter detection procedure may include at least one of a foreign matter detection procedure based on power loss and a foreign matter detection procedure based on temperature change. the additional foreign matter detection procedure may include at least one of a foreign matter detection procedure based on power loss and a foreign matter detection procedure based on temperature change. the additional foreign matter detection procedure may include at least one of a foreign matter detection procedure based on power loss and a foreign matter detection procedure based on temperature change.

[0276] FIG. 7 is a diagram for explaining the configuration of the transmission antenna of FIG. 6 according to an embodiment of the present invention. is.

[0277] Referring to FIG. 7, the transmission antenna 640 may include a coil selection circuit 710, a coil assembly 7 20 and a resonance capacitor 730.

[0278] The coil assembly 720 may include at least one transmission coil - that is, the first to Nth coils -.

[0279] The coil selection circuit 710 may include a switching circuit configured such that the inverter output current I_coil is transmitted to any one or at least any one of the transmission coils included in the coil assembly 720. The coil selection circuit 710 may include a switching circuit configured such that the inverter output current I_coil is transmitted to any one or at least any one of the transmission coils included in the coil assembly 720. The coil selection circuit 710 may include a switching circuit configured such that the inverter output current I_coil is transmitted to any one or at least any one of the transmission coils included in the coil assembly 720.

[0280] As an example, one end of the coil selection circuit 710 is connected to the inverter output stage, and the other end is It may be configured to include first to Nth switches connected to corresponding coils.

[0281] The first to Nth coils included in the coil assembly 720 may have one end thereof connected to the corresponding switch of the coil selection circuit 71 0 and the other end thereof may be connected to the resonance capacitor 730.

[0282] The demodulator 680 can demodulate a signal between the coil assembly 720 and the resonance capacitor 730 - here, the signal is an amplitude-modulated signal - and transmit it to the controller 610.

[0283] FIG. 8 is a block diagram for explaining the structure of a wireless power receiving device that operates in conjunction with the wireless power transmitting device according to FIG. 6 of the present invention. It is a block diagram for explaining the structure of a wireless power receiving device that operates in conjunction with the wireless power transmitting device according to FIG. 6 of the present invention.

[0284] Referring to FIG. 8, the wireless power receiver 800 may include a receiving antenna 810, a rectifier 820, a direct current / direct current converter (DC / DC Converter, 830), a switch 840, a load 85 0, a sensing unit 860, a modulation unit 870, and a main control unit 870.

[0285] The wireless power receiver 800 illustrated in the example of FIG. 8 can exchange information with the wireless power transmitter through in-band communication.

[0286] The receiving antenna 810 may be configured to include an inductor and at least one capacitor. It can be configured to include an inductor and at least one capacitor.

[0287] The AC power transmitted by the wireless power transmitter 600 can be transmitted to the rectifier 820 through the receiving antenna 810. The rectifier 820 can convert the AC power transmitted through the receiving antenna 810 into DC power and transmit it to the DC / DC converter 830.

[0288] The DC / DC converter 830 can convert the intensity of the output DC power of the rectifier 820 into DC power with a specific intensity required by the load 850. It can be converted into DC power with a specific intensity required by the load 850.

[0289] The sensing unit 840 can measure the intensity of the output DC power of the rectifier 820 and provide the measurement result to the main control unit 880. It can provide the measurement result to the main control unit 880.

[0290] The main control unit 880 can perform power control based on the output DC power of the rectifier 820. It can perform power control based on the output DC power of the rectifier 820.

[0291] In addition, the sensing unit 840 can measure the intensity of the current applied to the receiving antenna 810 by wireless power reception and transmit the measurement result to the main control unit 880. It can measure the intensity of the current applied to the receiving antenna 810 by wireless power reception and transmit the measurement result to the main control unit 880.

[0292] In addition, the sensing unit 840 can measure the internal temperature of the wireless power receiver 800 or the electronic device on which the wireless power receiver 800 is mounted and provide the measured temperature value to the main control unit 880. It can measure the internal temperature of the wireless power receiver 800 or the electronic device on which the wireless power receiver 800 is mounted and provide the measured temperature value to the main control unit 880. It can provide the measured temperature value to the main control unit 880.

[0293] As an example, the main control unit 880 can compare the measured intensity of the output DC power of the rectifier with a predetermined reference value to determine the presence or absence of overvoltage generation. If the determination result is that overvoltage has occurred, the main control unit 880 can transmit a predetermined packet notifying that overvoltage has occurred to the wireless power transmitter 600 through the modulation unit 870. It can transmit a predetermined packet notifying that overvoltage has occurred to the wireless power transmitter 600 through the modulation unit 870. It can transmit a predetermined packet notifying that overvoltage has occurred to the wireless power transmitter 600 through the modulation unit 870.

[0294] When a packet is received from the main control unit 880, the modulation unit 870 can generate an amplitude modulation signal corresponding to the received packet using the AC power received through the receiving antenna 810 and the provided switch. At this time, the wireless power transmitter 600 can wirelessly receive It can generate an amplitude modulation signal corresponding to the received packet using the AC power received through the receiving antenna 810 and the provided switch. It can generate an amplitude modulation signal corresponding to the received packet using the AC power received through the receiving antenna 810 and the provided switch. It can be demodulated through a demodulator 680 provided with a signal amplitude-modulated by a signal transmitter 800. Yes.

[0295] As an example, when the modulation unit 870 receives a signal strength packet from the main control unit 880 during the ping stage, it can amplitude-modulate the digital ping received through the receiving antenna 1010 to correspond to the received signal strength packet. The digital ping received through the receiving antenna 1010 can be amplitude-modulated to correspond to the received signal strength packet. Yes.

[0296] The modulation unit 870 according to one embodiment may be provided with a modulation switch for amplitude-modulating an AC power signal received through the receiving antenna 810. In this case, the main control unit 880 may transmit a pulse width modulation signal corresponding to the transmission target packet to the modulation unit 870 to directly control the modulation switch. Yes. The modulation switch may be directly controlled by transmitting a pulse width modulation signal corresponding to the transmission target packet to the modulation unit 870. Yes.

[0297] In addition, when the intensity of the output DC power of the rectifier is equal to or greater than a predetermined reference value, the main control unit 880 can determine that a sensing signal - for example, a digital ping - has been received. When the sensing signal is received, it can be controlled so that a signal strength packet corresponding to the corresponding sensing signal can be transmitted to the wireless power transmitter through the modulation unit 870. Yes. When the sensing signal is received, the main control unit 880 can control the signal strength packet corresponding to the corresponding sensing signal to be transmitted to the wireless power transmitter through the modulation unit 870. Yes.

[0298] As an example, when the internal temperature exceeds a predetermined reference value, the main control unit 880 can control the switch 840 - for example, turn off the switch - so that the output DC power of the DC / DC converter 830 is not transmitted to the load 850. At this time, the main control unit 880 can transmit a power transmission interruption packet including an overheat code to the wireless power transmitter 600 through the modulation unit 1070. Yes. The main control unit 880 can control the switch 840 to turn off so that the output DC power of the DC / DC converter 830 is not transmitted to the load 850. Yes. Yes.

[0299] As another example, the main control unit 880 is the internal part of an electronic device to which the wireless power receiver 800 is attached. A power management element for controlling power - for example, it can be interlocked with a PMIC (Power Management IC).

[0300] In this case, the output DC power of the DC / DC converter 1030 can be transmitted to the power management element through the switch 840, and the power management element can control the charging of the battery and the power supply to the internal components of the electronic device.

[0301] The power management element can provide the charging state information of the battery to the main control unit 880. Based on the charging state information and the internal temperature information of the battery, the main control unit 880 can judge whether the charging can proceed.

[0302] When the wireless power receiver 800 according to an embodiment of the present invention enters the negotiation stage 440, it can generate a foreign object detection state packet and transmit it to the wireless power transmitter 600.

[0303] As an example, the foreign object detection state packet can include a reference quality factor value.

[0304] As another example, the foreign object detection packet can include a reference quality factor value and the resonance frequency corresponding to the corresponding wireless power receiver.

[0305] As still another example, the foreign object detection packet may include a resonance frequency and a quality factor value corresponding to the resonance frequency.

[0306] Based on the reference quality factor value included in the foreign object detection state packet, the wireless power transmitter 600 can determine a predetermined threshold for judging the presence or absence of a foreign object.

[0307] The wireless power receiver 800 according to the embodiment of FIG. 8 above is the one transmitted by the wireless power It may further include a demodulation unit (not shown) for demodulating the packet.

[0308] Through this, the wireless power transmitter 600 and the wireless power receiver 800 can perform two-way communication as well. In one embodiment, the two-way communication may be time-division communication in which the packet transmission available time at the wireless power transmitter and the packet transmission available time at the wireless power receiver are divided, but it is not limited thereto.

[0309] FIG. 9 is a drawing for explaining a method of controlling power transmission according to the presence or absence of foreign object detection in a wireless power transmitter according to the prior art.

[0310] When the wireless power transmitter receives a negotiation request packet from the wireless power receiver, it can transmit an approval packet ( Grant Packet) and enter the negotiation stage 440.

[0311] Referring to FIG. 9, in the negotiation stage 440, the wireless power transmitter can receive a foreign object detection status packet (FOD (Foreign Object Detection) Status Packet) from the wireless power receiver (S901).

[0312] As an example, as shown in FIG. 10 below, the wireless power transmitter can receive a foreign object detection status packet including a reference quality factor value (Reference Quality Factor Va lue, 1031) in the message field 1030.

[0313] The wireless power transmitter can determine the presence or absence of a foreign object (S902). Here, after detecting an object in the selection stage 410, the wireless power transmitter is measured before entering the ping stage 420 ​​​​The quality factor determined based on the target quality factor value and the quality factor value received in negotiation stage 440 By comparing the threshold value, it is possible to determine the presence or absence of a foreign object.

[0314] In the following embodiments, as a method for detecting a foreign object after entering negotiation stage 44, a foreign object detection method based on the quality factor value will be described as an example. However, this is only one embodiment, and different foreign object detection methods may be applied by those skilled in the art according to the design or standard definition. It should be noted that this is only one example, and different methods may be applied by those skilled in the art according to the design or standard definition. It should be noted that different foreign object detection methods may be applied by those skilled in the art according to the design or standard definition. Attention must be paid to this.

[0315] If the determination result is that there is no foreign object, the wireless power transmitter can transmit an ACK signal to the corresponding wireless power receiver (S903). Transmit.

[0316] After that, the wireless power transmitter can receive a safeguard power packet containing information about the safeguard power required by the wireless power receiver (S904). Received.

[0317] The wireless power transmitter can receive a negotiation end packet from the wireless power receiver (S9 05).

[0318] When the wireless power transmitter receives the negotiation end packet, it can enter correction stage 450 in negotiation stage 440 Enter.

[0319] The wireless power transmitter can enter correction stage 450 and perform a predetermined correction procedure (S906 ).

[0320] When the power transmission contract is completed through the correction procedure, the wireless power transmitter can enter power transmission stage 460 Start charging (S907).

[0321] If it is determined in step 902 that a foreign object is present, the wireless power transmitter enters a foreign object detection state. In response to the state packet, a NACK signal can be transmitted (S908).

[0322] The wireless power receiver receives a NACK signal as a response to the foreign object detection status packet. and at its own output stage until the power signal received from the wireless power transmitter is completely removed. The power does not exceed a predetermined threshold, which may be, but is not limited to, 5W. It is possible to control it so that

[0323] The wireless power transmitter transmits a NACK signal within a predefined time period, e.g., 5 seconds. If necessary, the power transmission can be interrupted (S909).

[0324] When power transmission is interrupted, the wireless power transmitter may enter a selection stage 410 ( S910).

[0325] Transmitting power corresponding to a second power transmission mode when a foreign object is placed in the charging area. may increase the risk of equipment overheating.

[0326] Therefore, when a foreign object is detected in a conventional wireless power transmitter, the power transmission stage Blocking access to floor 460 and interrupting power transmission within a predefined time period before selecting Selection step 410 has been entered.

[0327] However, the wireless power transmitter is subject to the measurement error of the LCR meter installed, The difference in the mechanical design of the power supply and the wireless power receiver and the design of the coils attached to each Quality Factor Cross Calibration Error ration Error), the separation distance between the transmission coil and the reception coil - that is, Z d istance - and the position of the wireless power receiver disposed in the charging area - that is, XY displacement - etc., may cause a misjudgment that there is a foreign object when there is actually no foreign object. There is a possibility of misjudging as if there is one.

[0328] If, despite the fact that there is actually no foreign object, the power transmission is interrupted anyway and then returns to the selection stage This may cause serious inconvenience to the user.

[0329] In particular, a wireless power receiver applied to a smartphone etc. applies a shielding agent with a high magnetic permeability in order to reduce the thickness of the corresponding product, and is designed so that the thickness of the reception coil can be made as small as possible. It can be designed to be as small as possible. It can be.

[0330] In this case, the resistance R can become very large and the quality factor Q can become very small. Also, when a metal housing is applied to the corresponding product, the quality factor Q can become even lower. It can be even lower.

[0331] This can increase the probability of error in determining the presence or absence of a foreign object in the wireless power transmitter. It can increase.

[0332] For example, when an error occurs in determining the presence of a foreign object, a situation where the quality factor Q is measured low and judged as a foreign object even though the smartphone is placed in the charging area, a situation where not only the foreign object but also the smartphone are both placed in the charging area, etc. can be included. Even though it is placed in the charging area, a situation where the quality factor Q is measured low and judged as a foreign object, a situation where not only the foreign object but also the smartphone are both placed in the charging area, etc. can be included. It can include situations such as when both the foreign object and the smartphone are placed in the charging area.

[0333] Therefore, in order to solve the above-described problems of the prior art, a method for controlling power transmission in a wireless power transmitter that can prevent damage to the device due to overheating and minimize user inconvenience is required. While preventing damage to the device due to overheating, a method for controlling power transmission in a wireless power transmitter that can minimize user inconvenience is required. is required.

[0334] FIG. 10 is a drawing for explaining a packet format according to an embodiment of the present invention. .

[0335] The wireless power transmission stage 10 and the wireless power reception stage 20 according to the embodiment of the present invention can exchange packets through in-band communication, but this is only one example, and the corresponding packets may be exchanged through out-of-band communication. Referring to FIG. 10, the packet format 1000 used for information exchange between the wireless power transmission stage 10 and the wireless power reception stage 20 includes synchronization acquisition for demodulation of the corresponding packet and a preamble (Preamble, 101 0) field for identifying the exact start bit of the corresponding packet, a header (

[0336] Header, 1020) field for identifying the type of message included in the corresponding packet, a message (Message, 1030) field for transmitting the content (or payload) of the corresponding packet, and a checksum (Check sum, 1040) field for checking whether an error has occurred in the corresponding packet. The packet receiving stage may identify the size of the message 1 030 included in the corresponding packet based on the header 1020 value. Also, the types of stage-by-stage transmissible packets in FIG. 4 above may be defined by the header 1020 value, and in part, the value of the header 1020 may be defined to be shared at different stages of the wireless power transmission procedure. As an example, in the ping stage 420 and the power transmission stage 460

[0337]

[0338] .

[0338] Also, the types of stage-by-stage transmissible packets in FIG. 4 above may be defined by the header 1020 value, and in part, the value of the header 1020 may be defined to be shared at different stages of the wireless power transmission procedure. For example, in the ping stage 420 and the power transmission stage 460 ​An end power transfer packet for interrupting the power transmission of a wireless power transmitter may be defined by the same header 1020. The message 1030 includes data to be transmitted at the transmission stage of the corresponding packet. As an example,

[0339] the data included in the message 1030 field may be a report, a request, or a response to the other party, but is not limited thereto.

[0340] The packet format 1000 according to another embodiment of the present invention may further include at least one of transmission stage identification information for identifying the transmission stage at which the corresponding packet is transmitted and reception stage identification information for identifying the reception stage at which the corresponding packet is received.

[0341] Here, the transmission stage identification information and the reception stage identification information may include IP address information, MAC (Medium Access Control) address information, product identification information, etc., but are not limited thereto, and any information that can distinguish the reception stage and the transmission stage on the wireless charging system may be used.

[0342]

[0343] The packet format 1000 according to still another embodiment of the present invention may further include predetermined group identification information for identifying the corresponding reception group when the corresponding packet must be received by a plurality of devices.

[0343]

[0344] FIG. 11 is a flowchart for explaining a power transmission control method in a wireless power transmitter according to an embodiment of the present invention.

[0344] When the wireless power transmitter receives a negotiation request packet from the wireless power receiver, it can transmit an approval packet ( Grant Packet) and enter the negotiation stage 440.

[0345] Referring to FIG. 11, in the negotiation stage 440, the wireless power transmitter can receive a foreign object detection status packet (FOD (Foreign Object Detection) Stat us Packet) from the wireless power receiver (S1110).

[0346] As an example, as shown in FIG. 10, the wireless power transmitter can receive a foreign object detection status packet including a reference quality factor value (Reference Quality Factor Val ue, 1031) in the message field 1 030.

[0347] The foreign object detection in the negotiation stage 440 is a procedure of comparing a reference value received from the receiver with a measured value, and the reference value and the measured value can be various types of parameters. The reference value and the measured value can include, for example, a resonance frequency, a resistance, an inductance, etc., but are not limited thereto.

[0348]

[0349] The wireless power transmitter 710 can calculate a measured equivalent series resistance (Measure d ESR (Equivalent Series Resistance), ESR _ measured ) using the previously stored measured peak frequency (PF_measured) and

[0350] Here, ESR is a series resistance component parasitic on a capacitor or the like in an RLC series circuit. Elec The actual capacitors and inductors used in the air circuit are not ideal components with only capacitance or inductance. However, when connected in series with a resistor, they can be regarded as very approximately ideal capacitors and inductors. This resistor is defined as the equivalent series resistance (ESR). When connected in series with a resistor, they can be regarded as very approximately ideal capacitors and inductors. This resistor is defined as the equivalent series resistance (ESR). ESR).

[0351] The wireless power transmitter 710 can calculate the reference equivalent series resistance (Reference ESR, ESR using the received reference peak frequency (PF_reference) and reference quality factor value (Q_reference). nce ESR, ESR reference )(S708).

[0352] The wireless power transmitter 710 can detect foreign objects using ESR _measured and ESR reference (S709). As an example, the wireless power transmitter 710 can compare the ratio of ESR and ESR with a predetermined critical value to determine the presence or absence of foreign objects reference and ESR _measured . The presence or absence of foreign objects can be determined.

[0353] The wireless power transmitter can transmit an ACK response or a NACK response to the wireless power receiver according to the foreign object detection result.

[0354] When a NACK response is received from the wireless power transmitter, the wireless power receiver can control the electronic device (or battery / load) through the output terminal so that power with a certain intensity or higher is not supplied until the wireless power transmitter completely interrupts power transmission. Here, the power with a certain intensity or higher may be based on 5W, but is not limited thereto. until the wireless power transmitter completely interrupts power transmission. Here, the power with a certain intensity or higher is not supplied until the wireless power transmitter completely interrupts power transmission. Here, the power with a certain intensity or higher may be based on 5W, but is not limited thereto.

[0355] Hereinafter, the relationship between ESR, the quality factor value Q, and the frequency will be described.​

[0356] The quality factor value Q in an ideal RLC series circuit and a tuned radio frequency (TRF) receiver is given by the following Equation 1: where R, L, and C represent resistance, inductance, and capacitance respectively,

[0357] [Number]

[0358] and [Number] is [Number] the resonant frequency.

[0359] [Number] Since [Number] it follows that

[0360] ESR is always the AC resistance measured at the standard frequency, and a high ESR can increase component aging, heat generation and the ripple current.

[0361] [Number] can be calculated by

[0362] Therefore, in the above embodiment, ESR reference is [Number] calculated by _measured is

Number

[0363]

Number

[0364]

Number

[0365]

Number

[0366]

Number

[0367]

Number

[0368] At this time, the ratio of ESR referenc and ESR _measured can be calculated as follows

[0369]

Number

[0370]

Number

[0371] A wireless power transmitter according to an embodiment has an ESR referenc and an ESR _measured If the ratio exceeds a defined ratio threshold, it can be determined that a foreign object is present. Here, the ratio threshold can be determined based on experimental results. As an example,

Equation

[0372] In the following description, an embodiment will be mainly described in which the wireless power transmitter determines the presence or absence of a foreign object based on the measured quality factor value and the determined quality factor threshold. Based on this, the presence or absence of a foreign object can be determined by comparing the measured quality factor value and the determined quality factor threshold.

[0373] The wireless power transmitter can determine the presence or absence of a foreign object (S1120). Here, After detecting an object in the selection stage 410, the wireless power transmitter can determine the presence or absence of a foreign object by comparing the measured quality factor value before entering the ping stage 420 with the quality factor threshold determined based on the reference quality factor value received in the negotiation stage 440. Based on this, the presence or absence of a foreign object can be determined by comparing the measured quality factor value and the determined quality factor threshold. If the determination result is that no foreign object is present, the wireless power transmitter can transmit a first response signal to the corresponding wireless power receiver (S1130). Here, the first response signal can be an ACK signal.

[0374] If the determination result is that no foreign object is present, the wireless power transmitter can transmit a first response signal to the corresponding wireless power receiver (S1130). Here, the first response signal can be an ACK signal. If the determination result is that no foreign object is present, the wireless power transmitter can transmit a first response signal to the corresponding wireless power receiver (S1130). Here, the first response signal can be an ACK signal. .

[0375] After transmitting the first response signal, the wireless power transmitter can perform a first power transmission control procedure (S11 40).

[0376] If the determination result at step 1120 is that a foreign object is present, the wireless power transmitter can transmit a second response signal (S1150). Here, the second response signal can be a NACK signal. If the determination result at step 1120 is that a foreign object is present, the wireless power transmitter can transmit a second response signal (S1150). Here, the second response signal can be a NACK signal.

[0377] The wireless power transmitter can perform a second power transmission control procedure after transmitting the second response signal (S11 60).

[0378] Here, the detailed configurations of the first power transmission control procedure and the second power transmission control procedure will become clearer through the description of the drawings described later.

[0379] FIG. 12 is a flowchart for explaining a power transmission control method in a wireless power transmitter according to another embodiment of the present invention for.

[0380] When the wireless power transmitter receives a negotiation request packet from the wireless power receiver, it can transmit an approval packet ( Grant Packet) and enter the negotiation stage 440.

[0381] Referring to FIG. 12, in the negotiation stage 440, the wireless power transmitter can receive a foreign object detection status packet (FOD (Foreign Object Detection) Stat us Packet) from the wireless power receiver (S1201). As an example, the wireless power trans mitter can receive a foreign object detection status packet including a reference quality factor value (Reference Quality Factor Value, 1031) in the message field 1030 as shown in FIG. 10 below .[[]END]

[0382] The wireless power transmitter can determine the presence or absence of a foreign object (S1202). Here, after detecting an object in the selection stage 410, the wireless power transmitter determines based on the quality factor value measured before entering the ping stage 420 and the reference quality factor value received in the negotiation stage 440 and compares it with the quality factor threshold value to determine the presence or absence of a foreign object. .[[]END]

[0383] If the determination result is that there is no foreign object, the wireless power transmitter can transmit a first response signal to the corresponding wireless power receiver . Here, the first response signal can be an ACK signal .

[0384] When the wireless power transmitter receives the first response signal, it can perform a first power transmission control procedure (S1140 ).

[0385] Hereinafter, the first power transmission control procedure (S1140) will be described in detail.

[0386] When the wireless power transmitter determines that there is no foreign object, it can set the guaranteed power to the maximum power (Maximum m or potential power). As an example, the maximum power can be 15W, but it is not limited to this, and it may be larger depending on the configuration and design of the wireless charger .

[0387] During the negotiation stage, the wireless power transmitter can transmit a transmitter power capability packet including the set guaranteed power to the wireless power receiver. Thereby, the wireless power receiver can determine the required power within the guaranteed power of the transmitter .

[0388] The wireless power transmitter can receive a guaranteed power packet including information about the guaranteed power (or required power) requested by the wireless power receiver (S1204).

[0389] The wireless power transmitter can receive a negotiation end packet from the wireless power receiver (S1 205).

[0390] When the wireless power transmitter receives the negotiation end packet, in negotiation stage 440, correction stage 450 It can enter.

[0391] The wireless power transmitter can enter the correction stage 450 and perform the correction procedure (S1206).

[0392] When the correction procedure of the wireless power transmitter is completed, it can enter the power transmission stage 460 and start charging (S1207).

[0393] If it is determined in the S1202 stage that there is a foreign object, the wireless power transmitter can transmit a second response signal as a response to the foreign object detection status packet (S1208). Here, the second response signal can be a NACK signal.

[0394] When the wireless power receiver receives the second response signal as a response to the foreign object detection status packet, it can perform the second power transmission control procedure (S1160). (S1160).

[0395] Hereinafter, the second power transmission control procedure (S1160) will be described in detail.

[0396] If it is determined that there is a foreign object, the wireless power transmitter can limit the guaranteed power to the first power, that is, the minimum guaranteed power (for example, 5W), and transmit the power (S1209 ). When the wireless power transmitter determines that there is a foreign object and sets the guaranteed power to 5W, it can determine the presence or absence of a foreign object based on a preset boundary value (or reference value) for power loss. Here, since 5W is the minimum power predetermined between the transmitter and the receiver, the wireless power transmitter can set a solid reference value to determine a foreign object. A foreign object detection method based on power loss and other foreign object detection methods may be applied.

[0397] ​​​​​​​ Here, the first power may be guaranteed power corresponding to the first power transmission mode. As an example, the first power can be set to 5W, but is not limited thereto, and may be set to a specific power smaller than 5W. At this time, it should be noted that the wireless power transmitter does not interrupt the transmission of the wireless power signal.

[0398] The wireless power transmitter can receive a guaranteed power packet (S1210). Here, the guaranteed power packet can include information regarding the required power determined by the wireless power receiver within the available guaranteed power of the wireless power transmitter.

[0399] When the wireless power transmitter receives a negotiation end packet from the wireless power receiver, it ends negotiation stage 44 0 and enters the power transmission stage (S460) to perform charging with the preset first power (S1212).

[0400] In the embodiment of FIG. 12, it is described that the wireless power transmitter receives a guaranteed power packet and a negotiation end packet during the execution of the second power transmission control procedure (S1160). However, this is only one embodiment, and in other embodiments, at least one of the guaranteed power packet and the negotiation end packet may not be received by the wireless power transmitter.

[0401] The wireless power transmitter according to the embodiment of the present invention may not perform correction stage 450 during the execution of the second power transmission control procedure (S1160).

[0402] Here, correction stage 450 may mean a process of comparing the transmission power of the transmitter and the reception power of the receiver so as to accurately measure values for the transmission power, reception power, and power loss between the transmitter and the receiver. ​​​​​​​​

[0403] At this time, in the second power transmission mode where the guaranteed power is 5 W or more, the greater the transmitted power, since the power loss may change, this is predicted (calculated) in advance, and when the transmitted power changes, the power loss can be calculated more accurately by reflecting the predicted value in advance. . However, in the first power transmission mode where the guaranteed power is set to the minimum power of 5 W, since it operates with a fixed power as the target, there is no need to perform a separate correction step 450. .

[0404] In addition, when correcting at least one of the transmitted power, received power, and loss power in the presence of a foreign object, since the correction is performed including the influence of the foreign object, in practice, there is a possibility of increasing the probability that the wireless power transmitter determines that there is no foreign object even though there is a foreign object. That is, the accuracy of foreign object determination may be reduced.

[0405] The present invention can improve the foreign object detection accuracy by controlling so that the correction step 450 is not performed during the execution of the second power transmission control procedure (S1160).

[0406] FIG. 13 is a diagram for explaining a power transmission control method in a wireless power transmitter according to still another embodiment of the present invention.

[0407] Referring to FIG. 13, the wireless power transmitter can enter the power transmission stage 460 (S1310) when the second power transmission control procedure (S1160) is completed.

[0408] The wireless power transmitter calculates the power loss based on the received power packet received during power transmission - that is, charging - in the power transmission stage 460. ​ The loss can be measured (or calculated or estimated) (S1320).

[0409] Hereinafter, for the sake of convenience of explanation, it will be described as if the wireless power transmitter measures the power loss. However, this is only one example, and it should be noted that the power loss can be calculated or estimated based on the transmission power measurement result in the wireless power transmission stage and the received power measurement result received from the wireless power reception stage. It must be noted.

[0410] As an example, during charging in the power transmission stage 460, based on the received power packet received from the wireless power receiver for a predetermined time, the power loss can be measured (or estimated).

[0411] Here, the power loss can include at least one of the first power loss measured based on the first received power value measured in a state where the wireless power receiver is not connected to the battery (or load), and the second power loss measured based on the second received power value measured in a state where the wireless power receiver is connected to the battery (or load).

[0412] As an example, the wireless power transmitter can measure the power loss every time a received power packet is received for a predetermined time, for example, 10 minutes, and determine the average value (or the smallest value or the largest value) of the measured power losses as the final power loss.

[0413] As another example, the wireless power transmitter may measure the power loss corresponding to N received power packets continuously received after entering the power transmission stage 460.

[0414] ​​​​​​​​​The wireless power transmitter can determine the presence or absence of foreign objects based on the measured power loss. (S1330).

[0415] As an example, when the measured power loss exceeds a predetermined power loss threshold value, the wireless power transmitter can determine that a foreign object is present. On the contrary, if the measured power loss is equal to or less than the predetermined power loss threshold value, it can be determined that no foreign object is present.

[0416] As another example, if the power loss estimated corresponding to N received power packets continuously received after entering the power transmission stage is all within the predetermined power loss threshold value, it can be determined that no foreign object is present. In the case where it is within the threshold value during a specific time, or when the power loss is within the threshold value after exceeding a specific time, it can also be determined that there is no foreign object. On the contrary, if the power loss estimated corresponding to at least one of the N received power packets continuously received after entering the power transmission stage exceeds the predetermined power loss threshold value, the wireless power transmitter can determine that a foreign object is present.

[0417] If it is determined that a foreign object is present, the wireless power transmitter can interrupt power transmission and enter the selection stage . (S1340 and S1350). If it is determined in the step 1330 that no foreign object is present, the wireless power transmitter can enter the renegotiation stage

[0418] and renegotiate the power transmission contract with the wireless power receiver. (S1360). At this time, the guaranteed power to be negotiated can be 5W or more.

[0419] If it is determined in the 1330 stage that no foreign object is present, the wireless power transmitter can enter the renegotiation stage and renegotiate the power transmission contract with the wireless power receiver. (S1360). At this time, the guaranteed power to be negotiated can be 5W or more.

[0420] The wireless power transmitter can re-enter the power transmission stage 460 according to the re-negotiation result and continue to perform charging on the corresponding wireless power receiver. Here, after re-negotiation, the wireless power transmitter can transmit power between the first power and the second power to perform charging. Here, the first power can be 5W and the second power can be 15W, but this is only one example, and the intensity of the second power can be greater or smaller than that. For example, if no foreign object is detected after the wireless power transmitter enters the power transmission stage, the transmission power intensity can be increased and the charging time can be shortened by converting from the first power transmission mode to the second power transmission mode through re-negotiation. As an example, after the wireless power transmitter enters the power transmission stage, if no foreign object is detected, the transmission power intensity can be increased and the charging time can be shortened by converting from the first power transmission mode to the second power transmission mode through re-negotiation. Here, the first power is 5W and the second power can be 15W, but this is only one example, and the intensity of the second power can be greater or smaller than that. Here, the first power is 5W and the second power can be 15W, but this is only one example, and the intensity of the second power can be greater or smaller than that.

[0421] For example, if no foreign object is detected after the wireless power transmitter enters the power transmission stage, the transmission power intensity can be increased and the charging time can be shortened by converting from the first power transmission mode to the second power transmission mode through re-negotiation. For example, if no foreign object is detected after the wireless power transmitter enters the power transmission stage, the transmission power intensity can be increased and the charging time can be shortened by converting from the first power transmission mode to the second power transmission mode through re-negotiation. For example, if no foreign object is detected after the wireless power transmitter enters the power transmission stage, the transmission power intensity can be increased and the charging time can be shortened by converting from the first power transmission mode to the second power transmission mode through re-negotiation.

[0422] FIG. 14 is a diagram for explaining a power transmission control method in a wireless power transmitter according to still another embodiment of the present invention. Referring to FIG. 14, the wireless power transmitter can enter the power transmission stage 460 after the second power transmission control procedure (S1160) is completed (S1410).

[0423] Referring to FIG. 14, the wireless power transmitter can enter the power transmission stage 460 after the second power transmission control procedure (S1160) is completed (S1410). Referring to FIG. 14, the wireless power transmitter can enter the power transmission stage 460 after the second power transmission control procedure (S1160) is completed (S1410).

[0424] The wireless power transmitter can measure the temperature change during power transmission in the power transmission stage 460 (S1420). The wireless power transmitter can measure the temperature change during power transmission in the power transmission stage 460 (S1420).

[0425] As an example, during power transmission in the power transmission stage 460, the wireless power transmitter can measure the amount of internal temperature change or the temperature change ratio per unit time. Here, the position where the temperature change is measured on the wireless power transmitter can be the transmission coil of the transmission antenna 640, but it is not limited thereto, and other positions of the wireless power transmitter - for example, equipped on the wireless power transmitter As an example, during power transmission in the power transmission stage 460, the wireless power transmitter can measure the amount of internal temperature change or the temperature change ratio per unit time. Here, the position where the temperature change is measured on the wireless power transmitter can be the transmission coil of the transmission antenna 640, but it is not limited thereto, and other positions of the wireless power transmitter - for example, equipped on the wireless power transmitter As an example, during power transmission in the power transmission stage 460, the wireless power transmitter can measure the amount of internal temperature change or the temperature change ratio per unit time. Here, the position where the temperature change is measured on the wireless power transmitter can be the transmission coil of the transmission antenna 640, but it is not limited thereto, and other positions of the wireless power transmitter - for example, equipped on the wireless power transmitter As an example, during power transmission in the power transmission stage 460, the wireless power transmitter can measure the amount of internal temperature change or the temperature change ratio per unit time. Here, the position where the temperature change is measured on the wireless power transmitter can be the transmission coil of the transmission antenna 640, but it is not limited thereto, and other positions of the wireless power transmitter - for example, equipped on the wireless power transmitter The obtained control circuit board and charging bed - may be measured.

[0426] The wireless power transmitter according to another embodiment may receive temperature information determined by the wireless power receiver at a predetermined cycle during power transmission. The wireless power transmitter may measure a temperature change based on the temperature information received from the wireless power receiver.

[0427] The wireless power transmitter according to still another embodiment of the present invention may determine a final temperature change based on a first temperature change measured internally and a second temperature change measured based on the temperature information received from the wireless power receiver.

[0428] The wireless power transmitter can determine the presence or absence of a foreign object based on the measured temperature change (S1430). As an example, when the measured temperature change exceeds a predetermined temperature change threshold value, the wireless power transmitter can determine that a foreign object is present.

[0429] On the contrary, if the measured temperature change is equal to or less than the predetermined temperature change threshold value, the wireless power transmitter can determine that no foreign object is present.

[0430] If the determination result is that a foreign object is present, the wireless power transmitter can interrupt power transmission and enter the selection stage (S1440 and S1450).

[0431] If the determination result at step 1430 is that no foreign object is present, the wireless power transmitter can enter the renegotiation stage and renegotiate the power transmission contract with the wireless power receiver (S1460).

[0432] The wireless power transmitter can re - enter the power transmission stage 460 according to the renegotiation result and continue charging.

[0433] For example, if no foreign object is detected after entering the power transmission stage, the wireless power transmitter may By switching from the first power transmission mode to the second power transmission mode through negotiation, the transmission power The wireless power transmitter can increase the power intensity and shorten the charging time. In the transmission mode, the power can be transmitted between a first power and a second power, where the first power is The first power may be 5W and the second power may be 15W, but this is only one example. It may be less than or greater than 15W depending on the design and configuration of the wireless power transmitter by a person skilled in the art. .

[0434] FIG. 15 is a flow chart showing a power transmission control method in a wireless power transmitter according to still another embodiment of the present invention. 1 is a diagram for explaining the invention;

[0435] Referring to FIG. 15, the wireless power transmitter completes the second power transmission control procedure (S1160). Then, the power transmission step 460 can be started (S1510).

[0436] The wireless power transmitter receives a received power packet ( It is possible to measure the power loss of the Received Power Packet (S 1520).

[0437] As an example, in the power transmission step 460, feedback from the wireless power receiver during power transmission is The power is calculated based on the received power packet. The loss can be measured.

[0438] Here, the power loss is the loss when the wireless power receiver is not connected to the battery (or load). The first power loss measured based on the first received power value measured in the state, and the radio power receiver can include at least one of the second power losses measured based on the second received power value measured in the state of being connected to a battery (or load).

[0439] The radio power transmitter can determine the presence or absence of a foreign object based on the measured power loss (S1530). As an example, when the measured power loss exceeds a predetermined power loss threshold value, the radio power transmitter can determine that a foreign object is present. On the contrary, if the measured power loss is equal to or less than the predetermined power loss threshold value, it can be determined that no foreign object is present.

[0440] If the determination result is that a foreign object is present, the radio power transmitter can interrupt power transmission and enter the selection stage (S1540 and S1550).

[0441] If the determination result at step 1530 is that no foreign object is present, the radio power transmitter can measure the temperature change during power transmission in power transmission stage 4 60 (S1560).

[0442] As an example, during power transmission in power transmission stage 460, the radio power transmitter can measure the amount of internal temperature change or the temperature change ratio per unit time. Here, the position where the temperature change is measured on the radio power transmitter can be around the transmission coil, but is not limited thereto, and may be measured at other positions of the radio power transmitter according to the design of those skilled in the art.

[0443] The radio power transmitter according to other embodiments may receive temperature information determined by the radio power receiver at a predetermined cycle during power transmission. The radio power transmitter is the temperature received from the radio power receiver ​Temperature changes may be measured based on degree information.

[0444] A wireless power transmitter according to still another embodiment of the present invention determines a final temperature change based on a first temperature change measured internally and a second temperature change measured based on temperature information received from a wireless power receiver.

[0445] The wireless power transmitter can determine the presence or absence of a foreign object based on the measured temperature change (S1570). As an example, when the measured temperature change exceeds a predetermined temperature change threshold, the wireless power transmitter can determine that a foreign object is present. On the contrary, if the measured temperature change is equal to or less than the predetermined temperature change threshold, the wireless power transmitter can determine that no foreign object is present.

[0446]

[0447] If the determination result is that a foreign object is present, the wireless power transmitter can interrupt power transmission and enter the selection stage (S1540 and S1550).

[0448] If the determination result at step 1570 is that no foreign object is present, the wireless power transmitter can enter the renegotiation stage and renegotiate a power transmission contract with the wireless power receiver (S1580). The wireless power transmitter can re-enter the power transmission stage 460 according to the renegotiation result and continue charging.

[0449] As an example, when no foreign object is detected after the wireless power transmitter enters the power transmission stage, the transmission power can be increased and the charging time can be shortened by switching from the first power transmission mode to the second power transmission mode through renegotiation.

[0450] ​​​​​​​​​​​In the embodiment of FIG. 15, the wireless power transmitter performs a foreign object detection procedure based on power loss and then, as shown, performs a foreign object detection procedure based on temperature change according to the determination result However, this is only one embodiment, and the wireless power transmitter according to other embodiments performs a foreign object detection procedure based on temperature change and then, according to the determination result, may be embodied to perform a foreign object detection procedure based on power loss .

[0451] FIG. 16a is a flowchart for explaining a wireless power transmission control method by foreign object detection when the versions of the transmitter and the receiver are the same.

[0452] In the following description of the embodiment, it should be noted that the second version is a higher version than the first version and is the most recently released version.

[0453] Specifically, FIG. 16a is a flowchart for explaining a wireless power transmission control method by foreign object detection when the versions of both the transmitter and the receiver are lower versions - for example, 1.2V - and the same. Here, the version can be a version with respect to the WPC Qi standard.

[0454] Referring to FIG. 16a, when entering the negotiation stage, the first version transmitter 1610 can receive a FOD status packet from the first version receiver 1620 (S1601 ).

[0455] The first version transmitter 1610 determines the presence or absence of a foreign object based on the received FOD status packet, and if there is a foreign object in the determination result, it can transmit a NACK signal to the first version receiver 1620 (S1602 ). ​

[0456] The first-version receiver 1620 receives a NACK response signal for the FOD status packet Then, it can either not transmit any packets or transmit specific packets (S1 603).

[0457] When the first-version transmitter 1610 transmits a NACK signal to the first-version receiver 1620 it can interrupt power transmission within a certain time - for example, 5 seconds - (S160 4). At this time, the first-version transmitter 1610 can ignore any packets received from the first-version receiver 1620 .

[0458] FIG. 16b is a flowchart for explaining a wireless power transmission control method by foreign object detection when the versions of the transmitter and the receiver are different .

[0459] Specifically, FIG. 16b is a flowchart for explaining a wireless power transmission control method by foreign object detection when the receiver is of a higher version than the transmitter .

[0460] Referring to FIG. 16b, when entering the negotiation stage, the first-version transmitter 1630 can receive a FOD status packet from the second -version receiver 1640 (S1605 ).

[0461] The first-version transmitter 1630 determines the presence or absence of a foreign object based on the received FOD status packet, and if the determination result is that there is a foreign object, it can transmit a NACK signal to the second-version receiver 1640 (S1606).

[0462] The first-version receiver 1630 receives a NACK response signal for the FOD status packet ​Then, a general request packet (GRP: General Request Packet) containing power transmitter capability (PTC: Power Transmitter Capability) information can be transmitted to the first version transmitter 1630 (S1607). )

[0463] When the first version transmitter 1630 transmits a NACK signal to the second version receiver 1640 of a higher version than itself, it can ignore the received general request packet and interrupt power transmission within a certain time - for example, 5 seconds - (S1608).

[0464] FIG. 16c is a flowchart for explaining a wireless power transmission control method by foreign object detection when the versions of the transmitter and the receiver are the same.

[0465] Specifically, FIG. 16c is a flowchart for explaining a wireless power transmission control method by foreign object detection when the versions of the receiver and the transmitter are all higher versions - for example, 1.3V -

[0466] Referring to FIG. 16c, when entering the negotiation stage, the second version transmitter 1650 can receive an FOD status packet from the second version receiver 1660 (S1609). )

[0467] Based on the received FOD status packet, the second version transmitter 1650 determines the presence or absence of a foreign object. If there is a foreign object in the determination result, a NACK signal can be transmitted to the second version receiver 1660 (S1610).

[0468] The second version receiver 1660 receives a NACK response signal for the FOD status packet​​​​​​​​ Then, a general request packet (GRP: General Request Packet) containing power transmitter capability (PTC) information can be transmitted to the second version transmitter 1650 (S1611). Packet) can be transmitted to the second version transmitter 1650 (S1611). Packet) can be transmitted to the second version transmitter 1650 (S1611). )

[0469] When the second version receiver 1660 of the same version as itself receives a general request packet, a power transmission function packet with the guaranteed power set to the first power can be transmitted to the second version receiver 1660 (S1612). When the second version receiver 1660 of the same version as itself receives a general request packet, a power transmission function packet with the guaranteed power set to the first power can be transmitted to the second version receiver 1660 (S1612). When the second version receiver 1660 of the same version as itself receives a general request packet, a power transmission function packet with the guaranteed power set to the first power can be transmitted to the second version receiver 1660 (S1612).

[0470] At this time, the second version receiver 1660 can transmit a special request packet with the guaranteed power set to the first power to the second version transmitter 1650 (S1613). At this time, the second version receiver 1660 can transmit a special request packet with the guaranteed power set to the first power to the second version transmitter 1650 (S1613).

[0471] The second version transmitter 1650 transmits an ACK signal as a response to the special request packet (S1614), enters the power transmission stage, sets the guaranteed power to the first power, and can perform charging (S1615). The second version transmitter 1650 transmits an ACK signal as a response to the special request packet (S1614), enters the power transmission stage, sets the guaranteed power to the first power, and can perform charging (S1615). The second version transmitter 1650 transmits an ACK signal as a response to the special request packet (S1614), enters the power transmission stage, sets the guaranteed power to the first power, and can perform charging (S1615).

[0472] The wireless power transmitter according to the embodiment of FIG. 16c of the present invention has the advantage that even if a foreign object is detected during the negotiation stage, the guaranteed power can be adjusted downward to safely maintain the charging state. The wireless power transmitter according to the embodiment of FIG. 16c of the present invention has the advantage that even if a foreign object is detected during the negotiation stage, the guaranteed power can be adjusted downward to safely maintain the charging state.

[0473] In the embodiment of FIG. 16c, if the second version transmitter 1650 receives a special request packet with the guaranteed power set to a power greater than the first power at the 1613 stage, a NACK response can be transmitted to the second version receiver 1660 as a response to the special request packet. In the embodiment of FIG. 16c, if the second version transmitter 1650 receives a special request packet with the guaranteed power set to a power greater than the first power at the 1613 stage, a NACK response can be transmitted to the second version receiver 1660 as a response to the special request packet. In the embodiment of FIG. 16c, if the second version transmitter 1650 receives a special request packet with the guaranteed power set to a power greater than the first power at the 1613 stage, a NACK response can be transmitted to the second version receiver 1660 as a response to the special request packet. In the embodiment of FIG. 16c, if the second version transmitter 1650 receives a special request packet with the guaranteed power set to a power greater than the first power at the 1613 stage, a NACK response can be transmitted to the second version receiver 1660 as a response to the special request packet.

[0474] Figure 16d is a flowchart for explaining a radio power transmission control method by foreign object detection when the transmitter has a higher version than the receiver.

[0475] Specifically, Figure 16d is a flowchart for explaining a method of controlling radio power transmission during foreign object detection so that backward compatibility is maintained when the version of the receiver is a lower version than that of the transmitter - for example, at a first version - such as 1.2V.

[0476] Referring to Figure 16d, when entering the negotiation stage, the second - version transmitter 1670 can receive an FOD status packet from the first - version receiver 1680 (S1616).

[0477] The second - version transmitter 1670 determines the presence or absence of a foreign object based on the received FOD status packet. If the determination result is that there is a foreign object, a NACK signal can be transmitted to the first - version receiver 1680 (S1617).

[0478] As an example, when the first - version receiver 1680 receives a NACK response signal for the FOD status packet, it can transmit a general request packet (GRP: General Request Packet) containing power transmitter capability (PTC: Power Transmitter Capability) information to the second - version transmitter 1670 (S1618). As another example, depending on the type of the receiver, when the first - version receiver 1680 receives a NACK response signal for the FOD status packet, it may not transmit any packet to the second - version transmitter 1670. ​

[0479] When the second version transmitter 1670 transmits a NACK signal from the first version receiver 16 80 at a lower version than itself, the power transmitter capability with the guaranteed power set to the first power can transmit packets to the first version receiver 1680 (S1619).

[0480] As an example, the first version receiver 1680 can transmit a special request packet with the guaranteed power set to the first power to the second version transmitter 1670 (S1620). Other As another example, depending on the type of receiver, when the first version receiver 1680 receives a NACK response signal for the FOD status packet, it may not transmit any packets to the second version transmitter 1 670.

[0481] The second version transmitter 1650 transmits a NACK signal as a response to a special request packet (S1621) and can interrupt power transmission within a certain time - for example, 5 seconds, but not limited to this - period. By transmitting a NACK signal as a response to a special request packet, the second version transmitter 1650 can prevent the first version receiver 1680 from entering the correction phase after the negotiation phase ends.

[0482]

[0483] The method according to the above-described embodiment can be produced as a program for execution by a computer and stored in a computer-readable recording medium. Examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage devices, and the like.

[0483] A computer-readable recording medium may be distributed among computer systems connected to a network and computer-readable code may be stored and executed in a distributed manner. Thus, a functional program, code, and code segment for implementing the above-described method can be easily inferred by a programmer in the technical field to which the embodiments belong. It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention. Therefore, the above detailed description should not be construed in a limiting sense in all respects and should be considered as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

Industrial Applicability

[0484]

[0485]

[0486] ​

Claims

1. In a wireless power transmitter that transmits power to a wireless power receiver, a controller that determines the presence or absence of a foreign object; a transmission unit that transmits wireless power according to the presence or absence of the foreign object; and the controller receives a foreign object detection status packet including at least one of a reference quality factor and a reference peak frequency from the wireless power receiver, and detects the presence or absence of the foreign object based on the foreign object detection status packet, the controller transmits a NAK response indicating the presence of the foreign object to the wireless power receiver, or transmits an ACK response indicating the absence of the foreign object, the transmission unit transmits first power to the wireless power receiver in response to the transmitted NAK response, or transmits second power greater than the first power to the wireless power receiver in response to the transmitted ACK response, the power transmitter starts power transmission with fixed first power when the foreign object is present, or with the negotiated second power when the foreign object is absent, A wireless power transmitter.

2. The wireless power transmitter according to claim 1, wherein the transmission unit transmits third power between the first power and the second power based on a change in the power transmission environment.

3. The wireless power transmitter according to claim 1, wherein the first power is 5 W.

4. The wireless power transmitter according to claim 3, wherein the second power is 15 W.

5. The wireless power transmitter according to claim 1, wherein before transmitting power to the wireless power receiver, the foreign object detection status packet is received from the wireless power receiver to detect the presence or absence of the foreign object.

6. The wireless power transmitter according to claim 1, wherein the controller further detects the presence or absence of the foreign object based on a transmission power loss or a temperature change during transmission of the second power to the wireless power receiver.

7. The controller measures the intensity of the transmitted power transmitted to the power receiver, and receives intensity information of the received power corresponding to the measured intensity of the transmitted power from the wireless power receiver, estimates a power loss based on a difference value between the intensity of the transmitted power and the intensity of the received power, The wireless power transmitter according to claim 6, wherein the estimated power loss is compared with a preset power loss reference value to determine the presence or absence of the foreign object during a predetermined time interval.

8. The transmission unit transmits the first power to the wireless power receiver in response to the transmitted NAK response in order to prevent the power transmission to the wireless power receiver from being interrupted. The wireless power transmitter according to claim 1.

9. During the transmission of the first power, when the foreign object is detected again as being present, the transmission unit interrupts the power transmission. The wireless power transmitter according to claim 1.

10. During the transmission of the second power, when a state change of the wireless power transmitter occurs, the controller renegotiates the magnitude of the power transmission. The wireless power transmitter according to claim 1.

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