Wireless charging method and apparatus therefor

Abstract

To provide a wireless charging method and an apparatus therefor for accurately determining a foreign object to prevent a heat generation phenomenon, a decrease in charging efficiency, and waste of consumed power.SOLUTION: A wireless charging method in a wireless power transmitter includes the steps of: sensing an object in a charging region; measuring a Q value (quality factor value); receiving information including a reference Q value; detecting a foreign object using the measured Q value and the reference Q value; and transmitting a response signal that includes ACK or NAK information depending on whether the foreign object has been detected. The wireless power transmitter transmits information including a first guaranteed power value when the response signal includes the ACK information, and transmits information including a second guaranteed power value when the response signal includes the NAK information. The first guaranteed power value is greater than the second guaranteed power value.SELECTED DRAWING: Figure 14a

Description

[Technical Field]

[0001] The present invention relates to wireless power transmission technology, and in particular to a wireless charging method and a This relates to the device. [Background technology]

[0002] Portable devices such as mobile phones and laptops have batteries that store power and charge and discharge batteries. In order for the battery of such a device to be charged, an external charger is required. The power must be supplied by the device.

[0003] Generally, the electrical connection between the battery and the charging device that charges the battery As an example of a connection method, commercial power supply is received and converted into voltage and current corresponding to the battery. and a terminal supply method for supplying electrical energy to the battery through the terminals of the battery. Such terminal supply methods can be implemented using physical cables or Therefore, if you handle a lot of equipment that uses terminal supply, you will need to use a lot of cables. The boxes take up a considerable amount of work space, making it difficult to organize and also unsightly. The power supply method is designed to prevent instantaneous discharges caused by different potential differences between terminals, burns caused by foreign substances, and fires. This can cause problems such as wear, self-discharge, and reduced battery life and performance.

[0004] Recently, in order to solve these problems, charging methods that use wireless power transmission have been developed. A wireless charging system and a control method are presented. In the past, some mobile devices were not equipped with charging systems, and consumers had to purchase them separately. The wireless charging receiver accessory had to be purchased separately, so However, the demand for wireless charging is expected to increase rapidly, and in the future, However, it is expected that it will basically have wireless charging functionality.

[0005] Generally, a wireless charging system is a wireless power supply that supplies electrical energy by wireless power transmission. It receives the electrical energy supplied by the power transmitter and wireless power transmitter to charge the battery. It consists of a wireless power receiver.

[0006] Such a wireless charging system includes at least one wireless power transmission method (e.g., electromagnetic induction). It can transmit power by various methods (induction, electromagnetic resonance, RF wireless power transmission, etc.). do.

[0007] For example, a wireless power transmission system generates a magnetic field from a power transmitter coil, and The electromagnetic induction method uses the principle of electromagnetic induction, where electricity is induced in the receiving coil by the influence of the Various wireless power transmission standards based on electromagnetic induction are used. The standards are the Wireless Power Consortium (WPC) and the Air Fuel Alliance (formerly PMA, Power Matters All) This includes electromagnetic induction wireless charging technology as defined in the IEEE 802.11 standard.

[0008] As another example, the wireless power transmission method uses a transmission coil of a wireless power transmitter. The magnetic field is tuned to a specific resonant frequency to transmit power to a wireless power receiver located in close proximity. The electromagnetic resonance method is sometimes used. The method is based on the Air Fuel Alliance (formerly A4WP, Alliance for Wireless Charging), a standard organization for wireless charging technology. This may include resonant wireless charging technology as defined by the (Ess Power) standards organization.

[0009] As another example, wireless power transmission systems transmit low-power energy over long distances using RF signals. RF wireless power transmission methods may also be used to transmit power to a wireless power receiver located in the do.

[0010] On the other hand, in wireless charging systems, magnetic fields such as metals are present between the wireless power transmitter and the wireless power receiver. If there are foreign substances that absorb the charge, problems such as heat generation, reduced charging efficiency, and increased power consumption may occur. Therefore, an accurate method for detecting foreign substances is required. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been devised to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a wireless charging method and an apparatus and system therefor.

[0012] Another object of the present invention is to provide a wireless charging method and a method therefor that accurately determine whether a foreign substance is present. The present invention aims to provide an apparatus and system for:

[0013] Another object of the present invention is to provide a method for preventing wireless charging from being performed due to a conventional method of erroneously recognizing the presence of a foreign substance. To provide a wireless charging method and a device and system therefor that solve the problem of wireless charging not being possible is located.

[0014] The technical problems to be solved by the present invention are not limited to the above-mentioned technical problems. Another technical problem that has not been solved is that the present invention can be realized by those skilled in the art from the following description. It should be clearly understood by those who have it. [Means for solving the problem]

[0015] In order to solve the above technical problems, a wireless charging method according to an embodiment provides a wireless power receiving device. In a wireless charging method for a wireless power transmitter that wirelessly transmits power to a receiver, It includes the steps of detecting an object, measuring the Q value (Quality Factor Value), and determining the reference Q value. receiving information including the measured Q value and a reference Q value; and detecting a foreign substance using the measured Q value and a reference Q value. If the foreign substance is not detected, the first guaranteed power value is set to and if the foreign substance is detected, transmit information including a second guaranteed power value. and wherein the first guaranteed power value is greater than the second guaranteed power value.

[0016] In addition, the wireless charging method according to the embodiment may include measuring an internal temperature of the wireless power transmitter. and if the foreign substance is detected, the sensed temperature is maintained at a predetermined temperature for a predetermined period of time. and transmitting a guaranteed power having a third guaranteed power value if the temperature is lower than the predetermined temperature. The third guaranteed power value may be greater than the second guaranteed power value.

[0017] In a wireless charging method according to an embodiment, the second guaranteed power value is set to the maximum power of the wireless power transmitter. It may also have a low guaranteed power.

[0018] In the wireless charging method according to the embodiment, the step of detecting the foreign matter further comprises using the reference Q value. determining a critical Q value using a method for determining a critical Q value; and if the measured Q value is equal to or greater than the critical Q value, If the measured Q value is less than the critical Q value, the substance is determined to be undetected. and determining that the substance has been detected.

[0019] In addition, in the wireless charging method according to the embodiment, the critical Q value is reduced by 10% of the reference Q value. The value may be different.

[0020] In addition, in the wireless charging method according to the embodiment, when the foreign substance is detected, wireless charging is performed. If it is determined that wireless charging is to be performed, a second guaranteed power value is determined. If the user decides not to use wireless charging, the wireless charging can be stopped. Cut.

[0021] In addition, in the wireless charging method according to the embodiment, when the foreign substance is detected, wireless charging is performed. The step of determining whether or not the measurement is performed includes a step of determining an allowable Q value using the critical Q value and a step of determining an allowable Q value using the measurement. If the determined Q value is equal to or greater than the allowable Q value, it is determined to perform wireless charging, and and determining not to perform wireless charging if the value is less than the allowable Q value. Cut.

[0022] In addition, in the wireless charging method according to the embodiment, the allowable Q value is reduced by 20% of the critical Q value. The value may be different.

[0023] In addition, in the wireless charging method according to the embodiment, the sensed temperature is maintained at a predetermined temperature for a predetermined period of time. transmitting a guaranteed power having a third guaranteed power value when the temperature is lower than the temperature set for the first temperature; This can be done at the renegotiation stage.

[0024] In addition, in the wireless charging method according to the embodiment, when the foreign substance is not detected, the first guaranteed voltage When the information including the force value is transmitted, the correction step is performed and the power transmission step is started. If detected, transmitting information including the second guaranteed power value will allow the power transmission to continue without performing the correction step. The process can then proceed to the transport stage.

[0025] The wireless charging method according to the embodiment includes a wireless power transmitter that wirelessly transmits power to a wireless power receiver. Detecting an object in a charging area and measuring a Q value in the wireless charging method receiving information including a reference Q value; and determining whether the reference Q value is less than 50. and if the reference Q value is less than 50, using the measured Q value and the reference Q value. If the reference Q value is 50 or more, the measured Q value is performing a second foreign substance detection using a reference Q value; If the foreign substance is not detected, information including the first guaranteed power value is transmitted. If the second foreign substance is detected, the second foreign substance detection unit 100 transmits information including the second guaranteed power value. If no substance is detected, information including the first guaranteed power value is transmitted. and stopping wireless charging when the first guaranteed power value is equal to or greater than the second guaranteed power value. It may be greater than the power value.

[0026] In addition, the wireless charging method according to the embodiment may include measuring an internal temperature of the wireless power transmitter. and if the foreign substance is detected through the first foreign substance detection, for a predetermined time period. If the sensed temperature is lower than the preset temperature, a third guaranteed power value is supplied to the power supply. The method further includes transmitting a guaranteed power value, wherein the third guaranteed power value is greater than the second guaranteed power value. It's okay to listen.

[0027] The wireless charging device according to the embodiment includes one or more transmitting coils and an externally applied DC power. The power conversion unit converts the intensity of the signal, the communication unit exchanges information with external devices, and the sensor measures the Q value. The sensing unit receives information including the reference Q value through the communication unit and performs foreign substance detection. and a control unit, wherein the control unit detects foreign substances using the measured Q value and a reference Q value. If the foreign substance is not detected, the information including the first guaranteed power value is transmitted. If a substance is detected, information including a second guaranteed power value is transmitted, and the first guaranteed power value is the same as the previous It may be greater than the second guaranteed power value.

[0028] In the wireless charging device according to the embodiment, the sensing unit is provided inside the wireless power transmitter. The temperature is measured, and when the foreign substance is detected, the control unit If the sensed temperature is lower than the preset temperature, a guaranteed power value having a third guaranteed power value is set. may be transmitted, and the third guaranteed power value may be greater than the second guaranteed power value.

[0029] In a wireless charging device according to an embodiment, the second guaranteed power value is set to the maximum power of the wireless power transmitter. It may also have a low guaranteed power.

[0030] In the wireless charging device according to the embodiment, the foreign substance detection is performed by the control unit determining the reference Q value. If the measured Q value is equal to or greater than the critical Q value, the foreign material is If the measured Q value is less than the critical Q value, the foreign substance is determined to be undetected. It can be determined that it has been detected.

[0031] In addition, in the wireless charging device according to the embodiment, the critical Q value is reduced by 10% of the reference Q value. The value may be any value.

[0032] In addition, in the wireless charging device according to the embodiment, when the foreign substance is detected, the control unit: A determination is made as to whether or not to perform wireless charging, and if it is determined that wireless charging is to be performed, a second guaranteed power value is included. If the user decides not to use wireless charging, the wireless charging can be stopped. .

[0033] In addition, the wireless charging device according to the embodiment performs wireless charging when the foreign substance is detected. The control unit determines the allowable Q value using the critical Q value, and the measured If the measured Q value is equal to or greater than the allowable Q value, it is determined to perform wireless charging. If the Q value is less than the allowable Q value, it can be determined that wireless charging will not be performed.

[0034] In addition, in the wireless charging device according to the embodiment, the allowable Q value is reduced by 20% of the critical Q value. The value may be different.

[0035] In addition, the wireless charging device according to the embodiment may detect the detected temperature for the predetermined period. and transmitting a guaranteed power having a third guaranteed power value when the temperature is lower than the preset temperature. The floor can be renegotiated at a later stage.

[0036] In the wireless charging device according to the embodiment, when the foreign substance is not detected, the control unit In this case, when information including the first guaranteed power value is transmitted, the correction stage is executed and the power transmission stage is started. If the foreign substance is detected, the information including the second guaranteed power value is transmitted, and the correction step is performed. It is possible to move to the power transfer stage without any interruption.

[0037] The wireless charging device according to the embodiment includes one or more transmitting coils and an externally applied DC power. The power conversion unit converts the intensity of the signal, the communication unit exchanges information with external devices, and the sensor measures the Q value. and receiving information including a reference Q value through the communication unit, and the reference Q value is less than 50. and a control unit that determines whether the reference Q value is less than 50. If so, the first foreign substance detection is performed using the measured Q value and the reference Q value, and the reference Q value is If the Q value is 50 or more, the second foreign substance detection is performed using the measured Q value and the reference Q value. If the foreign substance is not detected through the first foreign substance detection, transmit information including a first guaranteed power value, and if the foreign substance is detected, transmit information including a second guaranteed power value. If the foreign substance is not detected through the second foreign substance detection, transmits information including a guaranteed power value, and when the foreign substance is detected, stops wireless charging, The first guaranteed power value may be greater than the second guaranteed power value.

[0038] In the wireless charging device according to the embodiment, the sensing unit is provided inside the wireless power transmitter. When the foreign substance is detected through the first foreign substance detection, If the sensed temperature is below a predetermined temperature for a predetermined period of time, a third A guaranteed power having a guaranteed power value is transmitted, and the third guaranteed power value is greater than the second guaranteed power value. It can be big.

[0039] The wireless charging method according to the embodiment includes a wireless power transmitter that wirelessly transmits power to a wireless power receiver. In the wireless charging method, a step of measuring a Q value is performed before a ping phase. receiving a FOD status packet including a reference Q value in a negotiation phase; determining a critical Q value using the critical Q value; and determining an allowable Q value using the critical Q value. and detecting a first foreign substance based on the measured Q value and the allowable Q value. can.

[0040] In addition, in the wireless charging method according to the embodiment, the critical Q value is reduced by 10% of the reference Q value. The acceptable Q value may be a value that is reduced by 20% of the critical Q value.

[0041] In addition, in the wireless charging method according to the embodiment, the step of detecting the first foreign substance comprises: It can be determined whether the value is equal to or greater than the allowable Q value.

[0042] In addition, in the wireless charging method according to the embodiment, if the measured Q value is equal to or greater than the allowable Q value, The method may further include transmitting an ACK for performing wireless charging.

[0043] In addition, in the wireless charging method according to the embodiment, since the measured Q value is equal to or greater than the critical Q value, and after moving to the correction step, determining whether the measured Q value is equal to or greater than the critical Q value. If so, perform correction; if the measured Q value is less than the critical Q value, perform correction; The method may further include the step of:

[0044] In addition, the wireless charging method according to the embodiment may include detecting a second foreign substance after the power transmission step. The method may further include the step of performing

[0045] In the wireless charging method according to the embodiment, the second foreign substance detection is performed by detecting a received power value and a transmitted power value. If the power loss value determined based on the It can be determined that:

[0046] In the wireless charging method according to the embodiment, the second foreign substance detection is performed when the measured internal temperature value is If a predetermined critical temperature value is exceeded, it can be determined that foreign matter is present.

[0047] In the wireless charging method according to the embodiment, the FOD status packet further includes a reference frequency value. and, before the ping step, measuring a frequency value, and, in the negotiation step, determining a critical frequency value using the critical frequency value; and determining an allowable frequency value using the critical frequency value. and determining the first foreign matter based on the measured frequency value. and the allowable frequency value.

[0048] In the wireless charging method according to the embodiment, the critical frequency value is 10% of the reference frequency value. The allowable frequency value is an increased value of 20% of the critical frequency. That's fine.

[0049] In addition, in the wireless charging method according to the embodiment, the step of detecting the first foreign substance further comprises: It can be determined whether the wave number value is equal to or less than the allowable frequency value.

[0050] In addition, in the wireless charging method according to the embodiment, the measured frequency value is equal to or less than the allowable frequency value. If so, the method may further include transmitting an ACK for wireless charging.

[0051] In addition, in the wireless charging method according to the embodiment, the measured frequency value is equal to or less than the critical frequency value. After the step of determining whether the measured frequency value is the critical value or not and the step of correcting the measured frequency value, If the measured frequency value is less than the critical frequency value, a correction is performed to reduce the measured frequency value to the critical frequency value. If exceeded, not performing the correction.

[0052] In the wireless charging method according to the embodiment, the FOD status packet further includes a reference frequency value. and measuring an equivalent series resistance value before the ping step, and measuring the reference Q value and the equivalent series resistance value before the ping step. determining a critical equivalent series resistance value using the reference frequency value; and determining an allowable equivalent series resistance value using the resistance value of the first foreign material. The step of determining the equivalent series resistance may be based on the measured equivalent series resistance value and the allowable equivalent series resistance value. can.

[0053] In the wireless charging method according to the embodiment, the critical equivalent series resistance is The allowable equivalent series resistance is a value that is increased by 10% of the critical equivalent series resistance. The value may be increased by 20%.

[0054] In addition, in the wireless charging method according to the embodiment, the step of detecting the first foreign substance further comprises: It can be determined whether the equivalent series resistance is equal to or less than the allowable equivalent series resistance.

[0055] In addition, in a wireless charging method according to an embodiment, the measured equivalent series resistance is If the resistance is equal to or less than the string resistance value, the step of transmitting an ACK for wireless charging may be further included. can be done.

[0056] In addition, in the wireless charging method according to the embodiment, the measured equivalent series resistance is After the step of determining whether the resistance is equal to or less than the column resistance value and the step of correcting the resistance, the measured equivalent If the series resistance is less than or equal to the critical equivalent series resistance, a correction is performed and the measured equivalent series resistance is and not performing the correction when the series resistance exceeds the critical equivalent series resistance. It is possible.

[0057] The wireless charging device according to the embodiment includes one or more transmitting coils and an externally applied DC power. The power conversion unit converts the intensity of the signal, the communication unit exchanges information with external devices, and the sensor measures the Q value. a first difference detecting unit, ... and a control unit for performing material detection, the control unit determining a critical Q value using the reference Q value. and determining an allowable Q value using the critical Q value, and the first foreign substance detection is The Q value can be based on the determined Q value and the acceptable Q value.

[0058] In addition, in the wireless charging device according to the embodiment, the critical Q value is reduced by 10% of the reference Q value. The acceptable Q value may be a value that is reduced by 20% of the critical Q value.

[0059] In addition, in the wireless charging device according to the embodiment, the first foreign substance detection is performed by the control unit. It can be determined whether the obtained Q value is equal to or greater than the allowable Q value.

[0060] In a wireless charging device according to an embodiment, the control unit determines whether the measured Q value is within the allowable Q value. If the value is equal to or greater than this, an ACK can be sent to perform wireless charging.

[0061] In addition, in the wireless charging device according to the embodiment, after the transition to the correction stage, the control unit If the measured Q value is equal to or greater than the critical Q value, a correction is performed to adjust the measured Q value to the critical Q value. If it is less than the Q value, no correction is required.

[0062] In addition, in the wireless charging device according to the embodiment, after the transition to the power transmission stage, the control unit Quality detection can be performed.

[0063] In a wireless charging device according to an embodiment, the second foreign substance detection is performed by the control unit detecting a received power value If the power loss value determined based on the transmission power value exceeds a predetermined critical power loss value, the foreign object It can be determined that quality exists.

[0064] In the wireless charging device according to the embodiment, the second foreign substance detection is performed by the control unit. If the internal temperature value exceeds a predetermined critical temperature value, it can be determined that a foreign substance is present.

[0065] In a wireless charging device according to an embodiment, the FOD status packet further includes a reference frequency value. the sensing unit measures a frequency value, and the control unit uses the reference frequency value. determining a critical frequency value using the critical frequency value; determining an allowable frequency value using the critical frequency value; The first foreign substance detection may be based on the measured frequency value and the allowed frequency value.

[0066] In addition, in a wireless charging device according to an embodiment, the critical frequency value is 10% of the reference frequency value. The allowable frequency value is an increased value of 20% of the critical frequency. That's fine.

[0067] In addition, in the wireless charging device according to the embodiment, the first foreign substance detection is performed by the control unit. It can be determined whether the detected frequency value is equal to or less than the allowable frequency value.

[0068] In a wireless charging device according to an embodiment, the control unit determines whether the measured frequency value is within the permitted range. If the frequency is equal to or lower than the allowable frequency value, an ACK for wireless charging can be transmitted.

[0069] In addition, in the wireless charging device according to the embodiment, after the transition to the correction stage, the control unit If the measured frequency value is less than or equal to the critical frequency value, a correction is performed and the measured frequency If the value exceeds the critical frequency value, no correction may be performed.

[0070] In a wireless charging device according to an embodiment, the FOD status packet further includes a reference frequency value. The sensing unit measures an equivalent series resistance value, and the control unit determines the value of the equivalent series resistance value in a negotiation step. The critical equivalent series resistance is determined using the quasi-Q value and the reference frequency value. The first foreign substance detection is performed by determining an allowable equivalent series resistance value using the measured equivalent series resistance value. The allowable equivalent series resistance can be based on the equivalent series resistance value and the allowable equivalent series resistance value.

[0071] In the wireless charging device according to the embodiment, the critical equivalent series resistance is The allowable equivalent series resistance is a value that is increased by 10% of the critical equivalent series resistance. The value may be increased by 20%.

[0072] In addition, in the wireless charging device according to the embodiment, the first foreign substance detection is performed by the control unit. It can be determined whether the measured equivalent series resistance is equal to or less than the allowable equivalent series resistance.

[0073] In a wireless charging device according to an embodiment, the control unit is configured to If the equivalent series resistance is equal to or less than the allowable equivalent series resistance, an ACK for wireless charging can be transmitted. can.

[0074] In addition, in the wireless charging device according to the embodiment, after the transition to the correction stage, the control unit If the measured equivalent series resistance is equal to or less than the critical equivalent series resistance, a correction is performed. If the calculated equivalent series resistance exceeds the critical equivalent series resistance, correction may not be performed. .

[0075] In order to solve the above technical problems, the wireless charging method according to the embodiment is In a wireless charging method for a wireless power transmitter that wirelessly transmits power to a power receiver, The steps of sensing an object in the area, measuring an equivalent series resistance value and a peak frequency value, and receiving information including a Q value and a reference peak frequency value; and determining a critical peak frequency value; The peak frequency value, the first critical equivalent series resistance value and the critical peak frequency value are used to calculate different and detecting a substance, wherein the wireless power transmitter detects that the measured equivalent series resistance value is The measured peak frequency is equal to or greater than the first critical equivalent series resistance value, and If the frequency is above this threshold, it is determined that a foreign substance is present and power transmission is stopped. .

[0076] In addition, in the wireless charging method according to the embodiment, the step of determining the first critical equivalent series resistance value includes: determining a reference equivalent series resistance value using the reference Q value and the reference peak frequency value; The first critical equivalent series resistance is a value obtained by decreasing the reference equivalent series resistance by a predetermined ratio. The step of determining a value can be included.

[0077] In the wireless charging method according to the embodiment, the critical peak frequency value is a reference peak frequency value It may be larger.

[0078] In addition, in the wireless charging method according to the embodiment, the measured peak frequency value is the measured equivalent series resistance is equal to or less than the first critical equivalent series resistance value. If so, transmit information indicating that no foreign substance has been detected to the wireless power receiver. It is possible.

[0079] The wireless charging device according to the embodiment includes an inverter that converts DC power into AC power, a resonant capacitor, and a a resonant circuit including a capacitor and a transmitting coil, to which the AC power is applied, and a wireless power receiver A communication unit that demodulates the modulated in-band signal and a sensor that measures the voltage of the resonant circuit. The control unit detects an object in the charging area, and the sensing unit The Q value and the peak frequency value are determined based on the measured voltage, and the reference Q value is transmitted through the communication unit. and receiving information including a reference peak frequency value, and determining a first critical equivalent series resistance value and a critical peak determining a frequency value, and comparing the measured equivalent series resistance value, the measured peak frequency value, and the The first critical equivalent series resistance value and the critical peak frequency value are used to detect foreign matter. The wireless power transmitter is configured to: the measured peak frequency value is greater than or equal to the critical peak frequency value; If this is the case, it can be determined that a foreign substance is present and power transmission can be stopped.

[0080] In a wireless charging device according to an embodiment, the first critical equivalent series resistance value is determined based on the reference Q value and and the reference peak frequency value. [Effects of the Invention]

[0081] The effects of the wireless charging method and the device and system therefor according to the present invention will be explained as follows. It seems.

[0082] The present invention can provide a wireless charging method and an apparatus and system therefor. .

[0083] Furthermore, the present invention can accurately determine the presence of foreign substances.

[0084] In addition, the present invention accurately detects foreign substances and prevents heat generation, reduced charging efficiency, and wasted power consumption. It can prevent waste.

[0085] In addition, the present invention solves the conventional problem of wireless charging not being performed due to the incorrect recognition that a foreign substance is present. It can be decided.

[0086] In addition, the present invention increases the charging distance between the wireless power transmitter and the wireless power receiver. By distinguishing and determining the presence of foreign substances, the problem of unnecessary wireless charging is eliminated. can be solved. [Brief explanation of the drawings]

[0087] The drawings attached below are provided to aid in understanding the present invention and are included to illustrate the principles of the present invention. However, the technical features of the present invention are not limited to the specific drawings. The features disclosed in the drawings are not intended to be combined with one another to form new embodiments. It can be achieved. [Figure 1] 1 is a block diagram illustrating a wireless charging system according to an embodiment. [Figure 2] 1 is a state transition diagram for explaining a wireless power transmission procedure defined in the WPC standard. [Figure 3] 1 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment; [Figure 4] 4 is a block diagram illustrating the structure of a wireless power receiver that is linked to the wireless power transmitter of FIG. 3. [Figure 5] 1 is a diagram illustrating a wireless charging method in a wireless charging system according to an embodiment; [Figure 6] 1 is a diagram illustrating a wireless charging method in a wireless power transmitter according to an embodiment; [Figure 7] 10 is a diagram for explaining a method for detecting foreign matter according to a Q value. [Figure 8] 10 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment. [Figure 9] 10 is a diagram for explaining a method for detecting foreign matter according to a frequency value; [Figure 10] 10 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment. [Figure 11] 10 is a diagram illustrating a method for detecting foreign matter according to an equivalent series resistance value; [Figure 12a] 10 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment. [Figure 12b] 10 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment. [Figure 13] 10 is a diagram illustrating a wireless charging method in a wireless charging system according to another embodiment. [Figure 14a] 14 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 13; [Figure 14b] 14 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 13; [Figure 15a] 14b is a diagram illustrating a method for detecting a foreign substance in the wireless charging method of FIG. 14a. [Figure 15b] 14b is a diagram illustrating a method for determining whether to perform wireless charging in the wireless charging method of FIG. 14a. [Figure 16] 10 is a diagram illustrating a wireless charging method in a wireless charging system according to another embodiment. [Figure 17a] 17 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 16; [Figure 17b]17 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 16; [Figure 18] 10 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment. [Figure 19] 10 is a diagram illustrating a wireless charging method in a wireless charging system according to another embodiment. [Figure 20] 20 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 19; [Figure 21] 21 is a diagram for explaining a method of detecting foreign matter according to the Q value in FIG. 20. [Figure 22] 10 is a diagram illustrating a wireless charging method in a wireless charging system according to another embodiment. [Figure 23] 23 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 22; [Figure 24] 10 is a diagram illustrating a method for detecting foreign matter according to an equivalent series resistance value; [Figure 25] 10 is a diagram illustrating a wireless charging method in a wireless charging system according to another embodiment. [Figure 26] 26 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 25; [Figure 27] 10 is a diagram for explaining a method for detecting foreign matter according to a frequency value; [Figure 28] 10 is a diagram illustrating a wireless charging method in a wireless charging system according to another embodiment. [Figure 29] 29 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment of FIG. 28. DETAILED DESCRIPTION OF THE INVENTION

[0088] The apparatus and various methods to which the embodiments are applied will be described in more detail below with reference to the drawings. The suffixes "module" and "section" for components used in the following description are , are merely given or mixed to facilitate the drafting of specifications, and in themselves, They do not have mutually distinct meanings or roles.

[0089] All the components constituting the embodiment are combined into one or operate in combination. Although the present invention has been described as an embodiment, it is not necessarily limited to such an embodiment. Within the scope of the embodiment, all of the components may be selectively coupled to one or more other components. All of the components may be implemented as separate pieces of hardware. Although some or all of the components may be selectively combined to form one or more components, A program module that performs some or all of the functions combined with multiple hardware The computer program may be embodied as a computer program having the following structure: The code and code segments that make up the example can be easily understood by a person skilled in the art. Such a computer program is computer readable It is stored on a computer-readable medium and can be read by a computer. The computer program can be executed to implement the embodiments. Examples of the recording medium include magnetic recording media, optical recording media, carrier wave media, and the like.

[0090] In the description of the embodiment, it is assumed that the components are formed "above or below" or "before or after" each component. When used, "above or below" and "before or after" refer to the area where two components are directly adjacent to each other. It may also be formed by two components that are in contact with each other or by one or more other components being placed between the two components. include.

[0091] Furthermore, the terms "including," "comprise," or "have" used above are particularly Unless stated to the contrary, it means that the element can be inherent. It is understood that other elements are not excluded and that other elements may be included. All terms, including technical or scientific terms, are intended to be used without limitation. Insofar as the examples are concerned, the meanings are those that are commonly understood by a person having ordinary skill in the art to which the examples belong. Commonly used terms, like dictionary-defined terms, have the same meaning as the relevant It should be interpreted in accordance with the context of the technology, and in the examples, it is not explicitly defined. as long as it is not interpreted as idealized or overly formal.

[0092] In addition, in the description of the components of the embodiment, terms such as first, second, A, B, (a), and (b) are used. Such terms may be used to distinguish the component from other components. The term does not limit the essence, order, or sequence of the components. It is not intended that one component be "coupled," "coupled," or "connected" to another component. When a component is described as being connected to another component, the component is not directly connected or attached to the other component. However, it is not permitted to "connect," "couple," or "bond" any other components between the components. It should be understood that the term "connected" can also be used interchangeably.

[0093] In the description of the embodiments, the related publicly known techniques are well known to those skilled in the art. If it is determined that there is a risk of unnecessarily obscuring the gist of the embodiment as a matter of obviousness, , the detailed description of which will be omitted.

[0094] In the description of the embodiment, the device transmitting wireless power in the wireless power charging system is For the sake of clarity, the following description will be given of a wireless power transmitter, a wireless power transmitting device, a wireless power transmitter, a transmitting end, and a transmitter. , transmitting device, transmitting side, wireless power transmission device, wireless power transmitter, wireless charging device, etc. Also, the term "wireless power receiving device" will be used to express a device that receives wireless power from a wireless power transmitting device. For convenience of explanation, a wireless power receiving device, a wireless power receiver, a wireless power receiving device, a wireless power receiver The terms transmitter, receiving terminal, receiving side, receiving device, receiver terminal, etc. may be used interchangeably.

[0095] The wireless charging device according to the embodiment may be in the form of a pad, a stand, an AP (Access Point), or a small It can be configured as a base station, stand, ceiling-mounted, or wall-mounted. One transmitter can also transmit power to multiple wireless power receiving devices.

[0096] For example, a wireless power transmitter is typically placed on a desk or table. It has also been developed and applied to automobiles and can be used inside the vehicle. The wireless power transmitter is mounted on a stand that can be easily and stably fixed and installed. It is provided in the form.

[0097] The terminal according to the embodiment may be a mobile phone, a smartphone, a laptop, or the like. laptop computers, digital broadcasting terminals, PDAs (Personal Digital Assistants) ts), PMP (Portable Multimedia Player), navigation, MP3 player, electric toothbrush, It can be used in small electronic devices such as electronic tags, lighting devices, remote controls, and floats. However, the present invention is not limited to these, and the wireless power receiving means according to the embodiment may be installed and the battery may be charged. Any mobile device capable of transmitting data (hereinafter referred to as a "device") may be used, and a terminal or device may be used. The terms "device" and "device" are sometimes used interchangeably. It can also be mounted on unmanned aerial vehicles and air drones.

[0098] The wireless power receiver according to the embodiment is provided with at least one wireless power transmission method, and It is also possible to receive wireless power from the above wireless power transmitters simultaneously. The transmission method is at least one of the electromagnetic induction method, the electromagnetic resonance method, and the RF wireless power transmission method. Generally, a wireless power system includes a wireless power transmitter and a wireless power The power receiver receives control signals through in-band communication or BLE (Bluetooth Low Energy) communication. Here, in-band communication, BLE communication, is performed using pulse width modulation ( Pulse Width Modulation, Frequency Modulation, Phase Modulation, Amplitude Modulation, Amplitude and For example, the wireless power receiver may have a receiving coil. The current induced through the feedback signal (feedbackAC) is switched on and off in a predetermined pattern. By generating a K signal, various control signals and information can be transmitted to the wireless power transmitter. The information transmitted by the wireless power receiver can be used to determine various conditions, including the received power strength. In this case, the wireless power transmitter can determine whether the wireless power transmitter is connected to the power source or not based on the received power strength information. The charging efficiency or power transmission efficiency can be calculated using the above.

[0099] FIG. 1 is a block diagram illustrating a wireless charging system according to an embodiment.

[0100] Referring to FIG. 1, the wireless charging system mainly includes a wireless power transmitting terminal that transmits power wirelessly. 10, a wireless power receiving terminal 20 for receiving the transmitted power, and a The electronic device 30 is configured as follows.

[0101] For example, the wireless power transmitting end 10 and the wireless power receiving end 20 are used for wireless power transmission. In-band communication is performed to exchange information using the same frequency band as the operating frequency. As another example, the wireless power transmitting end 10 and the wireless power receiving end 20 may be Out-of-band communication is a method of exchanging information using a separate frequency band that is different from the operating frequency used for transmission. (Out-of-band) communication is also possible.

[0102] For example, the information exchanged between the wireless power transmitting end 10 and the wireless power receiving end 20 is It may contain not only status information but also control information. The state and control information will become more apparent from the description of the embodiments below.

[0103] The in-band and out-of-band communications may provide two-way communications, In other embodiments, the communication may be one-way or half-duplex. can also be provided.

[0104] For example, one-way communication is when the wireless power receiving end 20 transmits information only to the wireless power transmitting end 10. However, the present invention is not limited to this. It may also be a device for transmitting information to the line power receiving end 20.

[0105] The half-duplex communication method allows two-way communication between the wireless power receiving end 20 and the wireless power transmitting end 10. However, it has the characteristic that information can be transmitted by only one device at a time.

[0106] The wireless power receiving end 20 according to the embodiment can also acquire various status information of the electronic device 30. For example, the status information of the electronic device 30 may include current power consumption information, identifying the application being executed, and the like. information for distinguishing between battery, CPU usage information, battery charge status information, battery output voltage / The information may include, but is not limited to, current information from the electronic device 30. Any information that can be acquired and used for wireless power control may be used.

[0107] FIG. 2 is a state transition diagram for explaining a wireless power transmission procedure.

[0108] Referring to FIG. 2, according to the wireless power transmission procedure, the power transmission from the transmitter to the receiver is as follows: The main phases are Selection Phase 210, Ping Phase 220, Identification and Identification and Configuration Phase 230, Negotiation Phase se) 240, Calibration Phase 250, Power Transfer Phase It is divided into a 260 phase and a 270 renegotiation phase.

[0109] A selection step 210 is performed to determine whether a particular error or When a specific event is detected, the transition to the next step is made, for example, S202, S204, S2 08, S210, S212, where specific errors and specific events This will become more clear from the following description. Also, in the selection step 210, the transmitter It can monitor whether an object is present on the interface surface. When it is detected that an object has been placed on the surface of the interface, the process proceeds to step 220. In selection step 210, the transmitter sends out a very short pulse of Analog Ping. ) signal and generates an output based on the current change in the transmitting coil or primary coil. It can detect whether an object is present in the active area of ​​the surface. do.

[0110] If an object is detected in the selection step 210, the wireless power transmitter selects a wireless power resonant circuit, e.g. For example, the Q of one end and / or the other end of a transmitting coil and / or a resonant capacitor for wireless power transmission. The quality factor can be measured.

[0111] The wireless power transmitter includes a wireless power resonant circuit (e.g., a power transmission coil and / or a resonant capacitor). The peak frequency of the capacitor can be measured.

[0112] The Q value and / or peak frequency may be used to determine whether or not a foreign substance is present in a subsequent negotiation step 240. It is used to make judgments.

[0113] In the ping step 220, when the transmitter detects an object, it wakes up the receiver and sends a Digital Ping to identify whether the detected object is a wireless power receiver In the ping step 220, the transmitter transmits a response signal to the digital ping (S201). If a null, e.g., signal strength packet, is not received from the receiver, the process returns to selection step 210. Also, in the ping step 220, the transmitter receives a signal indicating that power transmission has been completed from the receiver. If a signal indicating that the charging has been completed is received, i.e., a charging completion packet, the process proceeds to selection step 210. This can also be done (S202).

[0114] Once the ping step 220 is complete, the transmitter identifies the receiver and returns receiver configuration and status information. The process may proceed to an identification and configuration step 230 to collect information (S203).

[0115] During the identification and configuration step 230, the transmitter detects if an unexpected packet is received. cket), if the desired packet is not received for a predefined period of time (time out), If there is a power transmission error or no power transmission contract is established power transfer contract), the process can proceed to selection step 210 (S204).

[0116] The transmitter receives the configuration packet in the identification and configuration step 230. Entry into the negotiation phase 240 is required based on the value of the Negotiation Field of You can check whether it exists or not.

[0117] If the result of the check indicates that negotiation is necessary, the transmitter can proceed to the negotiation stage 240 ( S205). During negotiation stage 240, the transmitter may perform a predetermined FOD detection procedure.

[0118] On the other hand, if the confirmation result indicates that negotiation is not necessary, the transmitter can directly proceed to the power transmission step 260. This is also possible (S206).

[0119] In the negotiation stage 340, the transmitter receives a Foreign Object Detection (FOD) signal containing a reference Q value. A status packet can be received, or a FOD status packet containing the reference peak frequency value can be received. Alternatively, a packet containing the reference Q value and the reference peak frequency value can be received. At this time, the transmitter can receive the status packet based on the reference Q value. The critical Q value for detection can be determined. The transmitter is based on the reference peak frequency value. The critical peak frequency value for FO detection can be determined using the

[0120] The transmitter uses the determined critical Q value for FO detection and the currently measured Q value, e.g., It is possible to determine whether FO exists in the charging area by using the Q value measured before the charging stage. It is possible to detect the F0 and control the power transmission according to the F0 detection result. This includes, but is not limited to, terminating power transmission when FO is detected. .

[0121] The transmitter determines the critical peak frequency value for FO detection and the currently measured peak frequency. The peak frequency value can be, for example, the peak frequency value measured before the ping stage. It is possible to detect whether FO is present in the charging area and transmit power according to the FO detection result. For example, if FO is detected, power transmission is stopped. However, it is not limited to this.

[0122] If FO is detected, the transmitter can return to the selection step 210 (S208). If the F0 is not detected, the transmitter goes through a correction stage 250 and then to a power transmission stage 260. Specifically, the transmitter detects the FO and If not, the transmitter receives the power intensity received at the receiving end in a correction step 250 and calculates the power intensity. The power loss at the receiving and transmitting ends can be measured by comparing the power intensity transmitted at each end. That is, the transmitter performs a correction step 250 to correct the difference between the transmission power at the transmitting end and the reception power at the receiving end. The power loss can be predicted based on the difference. The power loss threshold for detecting FOD can be adjusted to reflect the power loss. ,In the correction stage, since there is no FO, the coupling state of the receiver and the Determine the power loss due to the friendly metal component and calculate the predetermined power When additional power loss occurs other than the power loss, it can be determined that a foreign substance is present.

[0123] During the power transmission step 260, the transmitter detects if an unexpected packet is received. ), if the desired packet is not received for a predefined time (time out), A power transfer contract violation occurs. If charging is complete, the process may proceed to selection step 210 (S210).

[0124] In the power transmission step 260, the transmitter may renew the power transmission contract due to a change in the transmitter state, etc. If it is necessary to configure, the process may proceed to the renegotiation step 270 (S211). If the renegotiation is successfully completed, the transmitter can return to the power transfer stage 260 ( S213).

[0125] The power transfer agreement described above is set based on the status and characteristics information of the transmitter and receiver. For example, the transmitter status information may include information on the maximum amount of power that can be transmitted, the maximum amount of power that can be received, and the like. The receiver status information may include information on the number of receivers that can be accommodated, and the receiver status information may include information on the required power. It can include information such as:

[0126] If the renegotiation is not completed successfully, the transmitter will stop transmitting power to the receiver and restart the selection stage. It is also possible to move to floor 210 (S212).

[0127] FIG. 3 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment.

[0128] Referring to FIG. 3, the wireless power transmitter 300 includes a power supply unit 360, a DC-DC converter (DC DC-DC Converter 310, Inverter 320, Resonant Circuit 330, Sensing Unit 350, a communication unit 340, an alarm unit 370, and a control unit 380.

[0129] The resonant circuit 330 includes a resonant capacitor 331 and an inductor (or a transmitting coil) 332. ), and the communication unit 340 includes at least one of a demodulation unit 341 and a modulation unit 342. It is composed of:

[0130] The power supply unit 360 receives DC power from an external power terminal or a battery and converts DC to DC. The battery can be transferred to the converter 310. Here, the battery can be connected to the wireless power transmitter 30. 0 and is configured to be rechargeable, but this is only one example. or an external battery, and a power supply unit 360 of the wireless power transmitter 300 is connected to the power supply unit 360 via a predetermined cable. may be connected via

[0131] The DC-DC converter 310 receives the input from the power supply unit 360 under the control of the control unit 380. The intensity of the DC power to be supplied can be converted into DC power of a specific intensity. The DC converter 310 is configured as a variable voltage generator capable of adjusting the voltage intensity. However, it is not limited to the above.

[0132] The inverter 320 can convert the converted DC power into AC power.

[0133] The inverter 320 receives the DC power signal through a plurality of switch controls. can be converted into an AC power signal and output.

[0134] As an example, the inverter 320 is configured to include a full bridge circuit. However, it is not limited to this, and may be configured to include a half bridge. That's fine.

[0135] As another example, the inverter 320 may include both a half-bridge circuit and a full-bridge circuit. In this case, the control unit 380 controls the inverter 320 to be a half-block. It is possible to dynamically determine and control whether to operate in a bridge or full-bridge configuration. can.

[0136] The wireless power transmitter according to one embodiment may transmit power in response to the strength of the power required by the wireless power receiver. The bridge mode of the inverter 320 can be adaptively controlled accordingly.

[0137] Here, the bridge mode includes a half-bridge mode and a full-bridge mode. For example, if the wireless power receiver requires a low power of 5 W, the control unit 380 The inverter 320 can be controlled to operate in half-bridge mode.

[0138] On the other hand, if the wireless power receiver requires 15W of power, the control unit 380 operates in the full-bridge mode. As another example, the wireless power transmitter can be controlled to operate in a sensing mode. The bridge mode is adaptively determined according to the temperature, and the bridge mode is adjusted according to the determined bridge mode. The inverter 320 can also be driven by the same.

[0139] As an example, while transmitting wireless power in half-bridge mode, If the temperature of the device exceeds a predetermined reference value, the control unit 380 deactivates the half-bridge mode. Therefore, the full-bridge mode can be activated. The device increases the voltage through a full bridge circuit to transmit the same amount of power, The strength of the current flowing through the oscillation circuit 330 is reduced, so that the internal temperature of the wireless power transmission device is reduced to a desired level. It can be controlled to maintain a constant reference value or less.

[0140] Generally, the amount of heat generated in an electronic component mounted in an electronic device depends on the amount of heat applied to the electronic component. It is more sensitive to the strength of the current than to the strength of the voltage applied.

[0141] In addition, the inverter 330 can not only convert DC power to AC power, but also convert AC power The strength of the can also be changed.

[0142] As an example, the inverter 320 is used to generate AC power under the control of the control unit 380. The frequency of the Reference Alternating Current Signal is adjusted to The inverter 320 can also adjust the strength of the AC power being supplied. The frequency oscillator generates a reference AC signal having a frequency of 1 / 2 Hz. Another example, by way of example only, is where the frequency oscillator is configured separately from the inverter 320 to generate wireless power. It may be attached to one side of the transmitter 300 .

[0143] As another example, the wireless power transmitter 300 may be configured to operate the switch provided in the inverter 320. It further includes a gate driver (not shown) for controlling In this case, the gate driver receives at least one pulse width modulation signal from the control unit 380. and controlling the switches of the inverter 320 in response to the received pulse width modulated signal. The control unit 380 controls the duty cycle of the pulse width modulation signal. That is, the duty rate and phase are controlled to output the inverter 320. The control unit 360 can control the intensity of the power received from the wireless power receiving device. Adaptively adjusting the duty cycle and position of the pulse width modulated signal based on the feedback signal The phase can be controlled.

[0144] The sensing unit 350 measures the voltage / current of the DC-converted power and outputs the voltage / current to the control unit 380. In addition, the sensing unit 350 can determine whether overheating has occurred. In order to cut off the power, the internal temperature of the wireless power transmitter 300 or the internal temperature of the charging interface (surface) The side can be measured and the measurement result can be provided to the control unit 380. 80 is based on the voltage / current value or internal temperature value measured by the sensing unit 350. Therefore, the power supply from the power supply unit 380 can be cut off adaptively. A predetermined voltage is provided on one side of the current converter 310 to cut off the power supplied from the power supply unit 360. A power cut-off circuit may also be provided.

[0145] The sensing unit 350 senses the Q value, frequency value, equivalent series resistance value, etc. The sensing unit 350 may include various sensing elements for sensing The Q value, frequency value, equivalent series resistance value, etc. can be provided to the control unit 380. The sensing method of the sensing unit 350 will be described below with reference to FIGS.

[0146] The control unit 380 receives the sensed Q value, frequency value, equivalent series resistance value, etc. Using FOD status information including at least one of the reference Q value and the reference frequency value The method of detecting foreign substances by the control unit 380 will be described below with reference to FIGS. 6 to 18. This will be explained with reference to the following.

[0147] The modulation unit 342 modulates the control signal generated by the control unit 380 to modulate the resonance coil 33 Here, the modulation method for modulating the control signal is FSK (Frequency Shift Keying). ncy Shift Keying modulation method, Manchester Coding modulation method , PSK (Phase Shift Keying) modulation method, Pulse Width Modulation method, Dif This may include, but is not limited to, ferential bi-phase modulation. .

[0148] When the signal received through the transmission coil is detected, the demodulator 341 demodulates the detected signal. The demodulated signal can be transmitted to the control unit 380. For example, the demodulated signal can include a signal Signal strength indicator, Error Correction (EC) indicator for power control during wireless power transmission indicator, end of charge (EOC) indicator, overvoltage / overcurrent / overtemperature indicator, etc. However, various status information for identifying the status of the wireless power receiver may be used, without being limited to this. As another example, the demodulated signal may include information on a reference Q value and a reference frequency value. FOD status information including one or more of these values ​​may be included.

[0149] As an example, the wireless power transmitter 300 may use the same frequency as that used for wireless power transmission. The signal strength indicator is transmitted through in-band communication to a wireless power receiver. can be acquired.

[0150] In the above description of FIG. 3, the wireless power transmitter 300 and the wireless power receiver perform in-band communication. However, this is merely an example and may be used for wireless power signal transmission. Short-distance two-way communication can be performed using a frequency band different from the frequency band used. For short-range two-way communication, low-power Bluetooth communication, RFID communication, UWB communication, and ZigBee communication are used. It may be either one.

[0151] FIG. 4 is a diagram illustrating the structure of a wireless power receiver that is connected to the wireless power transmitter of FIG. 3. FIG.

[0152] Referring to FIG. 4, the wireless power receiver 400 includes a receiving coil 410, a rectifier 420, a DC / DC / DC Converter 430, Load 440, Sensing Unit 450, Communication Unit The communication unit 460 includes a demodulation unit 460 and a main control unit 470. 1 and modulation section 462.

[0153] The wireless power receiver 400 shown in the example of FIG. 4 wirelessly transmits power through in-band communication. Although shown as being able to exchange information with a power transmitter, this is only one example and other The communication unit 460 according to one embodiment may be configured to transmit a signal in a frequency band different from the frequency band used for wireless power signal transmission. It can also provide short-range two-way communication over frequency bands.

[0154] The AC power received through the receiving coil 410 can be transferred to the rectifier 420. The rectifier 420 converts the AC power into DC power and transmits it to the DC / DC converter 430. The DC / DC converter 430 can adjust the intensity of the DC power output by the rectifier. It can be converted into a specific intensity required by the load 440 and transmitted to the load 440 . The receiving coil 410 is made up of a plurality of receiving coils (not shown), i.e., first to nth receiving coils. In one embodiment, the signal is transmitted to each receiving coil (not shown). The frequencies of the AC power supplied may be different from each other, and in another embodiment, the LC resonance characteristics are set for each receiving coil. Each receiver is controlled by a predetermined frequency controller that has the function of adjusting the frequency differently. It is also possible to set different resonance frequencies for each receiving coil.

[0155] The sensing unit 450 measures the intensity of the DC power output from the rectifier 420 and outputs it to the main control For example, the sensing unit 450 may provide a wireless power receiving unit. The intensity of the current applied to the receiving coil 410 is measured by the 70. As another example, the sensing unit 450 may transmit the signal to the wireless power receiver 4 The internal temperature of the device can be measured and the measured temperature value can be provided to the main control unit 470. Cut.

[0156] For example, the main control unit 470 may determine whether the measured intensity of the DC power output by the rectifier is a desired value. It is possible to determine whether an overvoltage has occurred by comparing the detected voltage with a fixed reference value. If an overvoltage occurs, a specified packet is generated and modulated to notify the occurrence of the overvoltage. The signal modulated by the modulation unit 462 can be transmitted to the receiving unit 462. The power is transmitted to the wireless power transmitter through the receiving coil 410 or a separate coil (not shown). In addition, the main control unit 470 detects that the intensity of the DC power output by the rectifier is equal to or greater than a predetermined reference value. When the detection signal is received, it is determined that the detection signal is received. Controlling the signal strength indicator to be transmitted to the wireless power transmitter through the modulation unit 462. As another example, the demodulation unit 461 may be configured to demodulate the A between the receiving coil 410 and the rectifier 420. The DC power signal output from the rectifier 420 is demodulated to determine whether the sensing signal is received. The main control unit 470 can then provide the identification result. 470 is a signal strength indicator corresponding to the sensing signal transmitted through the modulation unit 462. It can be controlled.

[0157] Also, the main control unit 470 selects either one of the previously stored reference Q value and reference frequency value. The FOD status packet including one or more values ​​is transmitted to the wireless power transmitter through the modulation unit 462. It can be controlled so that it can be sent.

[0158] FIG. 5 is a diagram illustrating a wireless charging method in a wireless charging system according to an embodiment. is.

[0159] Referring to FIG. 5, the wireless power transmitter 610 transmits an analog signal to the wireless power receiver 620 in a selection step. A log ping can be transmitted (S601).

[0160] The wireless power transmitter 610 can measure the Q factor before the ping stage (S602). As an example, the wireless power transmitter 610 can measure the Q factor in the selection stage (S60 2).

[0161] Also, the wireless power transmitter 610 can measure the peak frequency value before the ping stage. As an example, the wireless power transmitter 610 measures the peak frequency value in the selection step (S603). As another example, the wireless power transmitter 610 may select a power source to be transmitted in the selection stage (S602). The peak frequency of the receiving coil can be measured to determine the inductance value. In essence, referring to Equation 1, the frequency value f is measured with a fixed capacitance value C. The inductance value can be used to determine the

[0162] (Equation 1) TIFF2025143356000002.tif2545 When an object is detected, the wireless power transmitter 610 transitions from the selection phase to the ping phase. The wireless power transmitter 610 activates the wireless power receiver 620 and A digital ping can be transmitted to identify the line power receiver 620. (S604). The wireless power receiver 620 sends a signal strength packet in response to the digital ping. The packet can be transmitted (S605).

[0163] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 620 receives the identification information transmitting an identification packet for informing the user of the configuration information and a configuration packet for informing the user of the configuration information; The wireless power transmitter 610 and the wireless power receiver 620 are configured as follows (S606 to S607). If the negotiation field value in the packet indicates that the negotiation phase is to be performed, It can be migrated.

[0164] During the negotiation phase, the wireless power receiver 620 transmits an FOD status packet to detect the FOD. The FOD status packet can be transmitted (S606). It can contain one or more of these values.

[0165] The wireless power transmitter 610 may perform a first foreign substance detection (S609). The detection is performed using the measured Q value, the measured frequency value, and the received FOD status packet information. The first foreign substance detection is performed by the wireless charging method shown in FIGS. See Ming.

[0166] When the wireless power transmitter 610 determines to perform wireless charging after performing the first foreign object detection, , transmitting an ACK to the wireless power receiver 620 in response to the FOD status packet. On the other hand, the wireless power transmitter 610 performs the first foreign substance detection and then wireless charging. When it decides to stop power supply, the wireless power receiver 6 sends a NAK in response to the FOD status packet. It can be transmitted to 20.

[0167] The wireless power receiver 620 receives a power transmission capability packet for a power transmission contract. The wireless power transmitter 62 may transmit a general request packet to request a power supply (S611). 0 can transmit a power transmitter power packet in response to a general request packet ( In this case, the guaranteed power of the power packet of the power transmission function is the first guaranteed power. It may also be a force value.

[0168] The potential power value is the power that a wireless power transmitter can transmit regardless of power limitations due to surrounding requirements, etc. For example, the first guaranteed power value may be a maximum transmission power value of the wireless power transmitter. The number of wireless power transmitters and the number of wireless power receivers are determined based on the power supply provided by the power source. Alternatively, the power consumption may be close to the potential power consumption that is not subject to the power limitations imposed by the first The guaranteed power value is determined based on the conditions (environment) such as power limitations due to the number of wireless power transmitters and the number of wireless power receivers. The maximum power that can be transmitted by the wireless power transmitter under the environmental conditions may be used. This includes the temperature of the transmitter, the available power source of the transmitter, the presence of foreign matter or friendly media. The wireless power receiver 620 can transmit power packets. Special requirements for proposing a guaranteed power value for a power transfer contract based on the first guaranteed power value of the contract It should be noted that the power transmission function can transmit a power request packet (S613). There is a distinction between the first guaranteed power of the grid and the guaranteed power of the power transmission contract. The line power receiver 620 receives a power signal equal to or smaller than the first guaranteed power value of the power transmission packet. For the sake of convenience, the guaranteed power value of the power transmission contract can be requested at a value. The power receiver 620 receives the first guaranteed power of the power packet from the power transmitter at the guaranteed power value of the power transmission contract. The wireless power transmitter 610 requests the guaranteed power value of the power transmission contract. An ACK packet can be transmitted in response to a special request packet to (S614) That is, the wireless power transmitter 610 receives the power transmission contract proposed by the wireless power receiver. In other words, the power transmission contract is completed at the first guaranteed power value. After that, when the power transmission contract is completed, the wireless power receiver 620 starts the negotiation stage. A special request packet for completing the floor may be transmitted (S615). The machine 610 sends an ACK packet in response to a special request packet to end the negotiation phase. That is, the wireless power transmitter 610 transmits the bit after the negotiation phase is completed (S616). An ACK packet can be transmitted as an acknowledgment for the

[0169] In the correction stage, the wireless power receiver 620 transmits the received power packet to the wireless power transmitter 610. In this case, the received power packet can be transmitted as a 24-bit received power packet (S617). The wireless power transmitter 610 may receive power packets to perform wireless charging. In response to the request, an ACK packet can be transmitted (S618).

[0170] The wireless power transmitter 610 may determine whether to perform correction (S619). The decision as to whether to perform the correction is made when entering the correction execution stage of FIGS. 6 to 13b. For example, when it is determined to perform the correction, the correction is performed by the wireless power transmitter 610 in step S617. The received power value of the wireless power receiver 610 of the received power packet received by The power loss can be predicted using the wireless power transmitter 610. The predicted power loss value is used for the second foreign object detection (S623) in the power transmission stage. The critical value of the power loss can be corrected. The strength of the transmission power can be increased by using the predicted power loss value of 0. The power transmitter 610 determines whether or not a foreign substance is present (if present), The correction does not have to be performed.

[0171] Once the correction step is completed, the power transmission step can be performed at the first guaranteed power. The transmitter 620 includes one or more controllers for controlling the current in the transmitting coil of the wireless power transmitter 610. The wireless power transmitter 610 can transmit a control error packet (S620). The current of the transmitting coil is controlled based on the control error packet transmitted from the power receiver 620. The wireless power receiver 620 can adjust the transmission power periodically or arbitrarily. A received power packet can be transmitted (S621).

[0172] The wireless power transmitter 610 may perform a second foreign substance detection (S622). , the wireless power transmitter 610 receives a power value that is the number of received power packets and a measured The transmission power value is used to determine the power loss, and the presence or absence of foreign matter is determined based on the power loss value. That is, if the power loss value exceeds a predetermined critical power loss value, the foreign object is detected. In this case, the wireless power transmitter 610 stops charging. In order to do so, the wireless power receiver 620 sends a NAK packet in response to the received power packet. After that, the wireless power transmitter 610 stops the wireless charging. As another example, the wireless power transmitter 610 may receive a power packet Whether or not a foreign object is present is detected using the internal temperature measured regardless of whether or not a signal is received. That is, if the internal temperature exceeds a predetermined critical temperature, it is possible to detect the presence of foreign matter. In this case, the wireless power transmitter 610 can stop wireless charging. This can be done.

[0173] Therefore, the wireless charging system according to the embodiment includes a wireless charging method and an apparatus therefor, and In addition, the wireless charging system according to the embodiment can provide a system for properly charging foreign substances. In addition, the wireless charging system according to the embodiment can accurately determine whether a foreign substance is present or not. As a result, heat generation, reduced charging efficiency, and wasted power consumption can be prevented.

[0174] FIG. 6 is a diagram illustrating a wireless charging method in a wireless power transmitter according to an embodiment. FIG. 7 is a diagram for explaining a method for detecting foreign matter according to the Q value.

[0175] Referring to FIG. 6, the wireless charging method in the wireless power transmitter calculates the Q value before the ping stage. In one example, the wireless power transmitter may include a measuring step (S701). The Q value can be measured using the sensing section.

[0176] The wireless charging method in the wireless power transmitter includes receiving an FOD status packet including a reference Q value. In one example, the wireless power transmitter may communicate during the negotiation stage (S702). The FOD status packet can be received using the unit. The Q value stored in the memory may be the Q value measured by a specific coil unit. The coil unit is the standard coil unit for comparing the Q value, and is The transmitter measures values ​​similar to those measured with a reference coil unit depending on the characteristics of the coil unit. The Q value must be calibrated accordingly. It is also possible to correct the reference Q value measured in the above to the value measured in the wireless power transmitter.

[0177] However, the reference Q value needs to be corrected (converted) or measured to match the characteristics of the wireless power transmitter. It is very difficult to correct (convert) the calculated value to fit the specific coil unit. The value is the intrinsic characteristic value of the coil unit, and energy storage and loss depend on the characteristic. Therefore, detecting foreign matter using the Q value can be subject to errors. For example, even when only the wireless power receiver is placed in the charging area, measurement errors and / or Due to calibration errors, it may be judged as a foreign substance. Wireless power receivers such as mobile phones The terminal equipped with the device has many components other than the wireless power receiver, and the standard Q value is very low. If the measured Q value or the corrected Q value is greater than the reference Q value (example: For example, if the material has a tolerance (exceeding the tolerance), it may generate a false alarm as a foreign material. Therefore, even if a foreign substance is detected in the first foreign substance detection stage, Additional actions can be taken without interrupting force transmission to determine whether or not a foreign object is present. This can be done.

[0178] The wireless charging method in the wireless power transmitter includes a step of determining a critical Q value (S703). More specifically, the wireless power transmitter can calculate the critical Q value by using the received reference Q value. As an example, the wireless power transmitter can calculate the reference Q value as follows: A value smaller than 10% can be determined as the critical Q value. 10% is the allowable limit for the reference Q value. If there is a foreign substance, the measured Q value will be smaller than the reference Q value by at least the allowable error. This can be used to detect foreign substances.

[0179] The wireless charging method in the wireless power transmitter includes a step of determining an allowable Q value (S704). More specifically, the wireless power transmitter can calculate the allowable Q by using the determined critical Q value. As an example, as shown in FIG. 7, the wireless power transmitter can calculate the critical Q value ( The value that decreases by 0% to 20% in Qth is determined as the allowable Q value (Qp). More specifically, wireless power transmitters can tolerate a 20% reduction in the critical Q value. The capacity Q can be determined as

[0180] The wireless charging method for the wireless power transmitter is to ensure that the measured Q value is equal to or greater than the determined allowable Q value. The step of determining whether to perform the operation (S705) may be included.

[0181] The wireless power transmitter can decide to perform wireless charging if the Q value is equal to or greater than the allowable Q value. If the Q value is less than the allowable Q value, the wireless power transmitter stops wireless charging (S706). For example, as shown in FIG. 8, if the frequency of the transmission power is the first When the frequency is 100 MHz, the wireless power transmitter measures the Q value as the first Q value (Q1), the second Q value (Q2), and the third Q value (Q3). If it is measured as the first Q value (Q1), the wireless power transmitter There is a very high probability that there is no foreign matter between the wireless power receiver and the If the third Q value (Q3) is measured, the third Q value (Q3) is considered to be clinically Since the Q value (Qth) is much lower than the standard Q value, there is no need to worry about the existence of foreign matter between the wireless power transmitter and the wireless power receiver. Since the probability of the presence of foreign matter is very high, it can be determined that foreign matter is present. 2), the second Q value (Q2) is between the critical Q value (Qth) and the allowable Q value (Qp). Therefore, there is a risk of misidentifying that a foreign substance exists between the wireless power transmitter and the wireless power receiver. To prevent this, the wireless power transmitter must ensure that the measured Q value is equal to or greater than the allowable Q value. Then, the wireless power transmitter performs the power transmission step S711. By performing a second foreign substance detection, it is possible to more accurately determine whether or not a foreign substance is present. Therefore, the wireless power transmitter determines to perform wireless charging if the Q value is equal to or greater than the allowable Q value. This allows the embodiment to accurately determine whether a foreign substance is present. In addition, one embodiment accurately detects foreign substances and prevents heat generation, reduced charging efficiency, and power consumption. In addition, in one embodiment, it is possible to prevent wasteful use of the material. This can solve the problem of wireless charging not working.

[0182] When the wireless power transmitter decides to perform wireless charging, it responds to the FOD status packet reception. In response, an ACK packet can be transmitted to the wireless power receiver (S707).

[0183] The wireless charging method for the wireless power transmitter is such that the Q value of the wireless power transmitter is equal to or greater than the critical Q value. More specifically, the wireless power transmitter may include a step of determining whether After deciding to implement wireless charging in the negotiation phase, the process moves to the correction phase, where it is decided whether to make corrections or not. In order to do this, it is possible to determine whether the Q value is equal to or greater than the critical Q value.

[0184] The wireless charging method for wireless power transmitters is as follows: For example, the method may include a step of transitioning to a correction step and performing the correction (S709). The correction is performed by the wireless power transmitter measuring the received power value of the wireless power receiver in the received power packet. The power loss can be predicted using the transmission power value obtained by the The power transmitter can then use the predicted power loss value to increase the strength of its transmitted power.

[0185] The wireless charging method for the wireless power transmitter is as follows: If so, it is possible to move to the power transmission step (S710) without the correction step.

[0186] The wireless charging method in the wireless power transmitter is a method of receiving a power packet after entering a power transmission stage. If the power supply voltage is received, the method may include performing a second foreign substance detection (S711). The device will perform a second foreign substance detection and stop wireless charging if it determines that a foreign substance has been detected. In addition, the wireless power transmitter can perform a second foreign substance detection (S712, S713). If it is determined that no foreign matter is detected, the power transmission stage can be maintained and the receiving If the received power packet is received, the second foreign substance detection can be performed again (S712, S7 11). For example, in the power transmission stage, the wireless power transmitter The power loss is determined using the power value, which is a numerical value, and the measured transmission power value, and the The wireless power transmitter can detect whether or not a foreign object is present by measuring the power loss value. If a predetermined critical power loss value is exceeded, it can be determined that a foreign substance is present. , the wireless power transmitter sends a NAK in response to the received power packet to stop charging. The packet can be sent to the wireless power receiver. Then, the wireless power transmitter can As another example, the wireless power transmitter may stop receiving the received power packet. Detect whether or not a foreign substance is present by using the internal temperature value measured regardless of whether or not it is present. That is, if the internal temperature exceeds a predetermined critical temperature, it is determined that a foreign substance is present. In this case, the wireless power transmitter can stop wireless charging. Therefore, in one embodiment, even if foreign matter is suspected to be detected during the negotiation stage, wireless charging is not stopped and wireless charging is continued. After charging, foreign matter is detected again at the power transmission stage to accurately determine whether foreign matter is present. It can be judged as follows.

[0187] When the wireless power transmitter determines to stop wireless charging in S714, it sends an FOD status packet A NAK packet can be sent to the wireless power receiver in response to the reception (S7 15) After that, the wireless power transmitter can stop wireless charging (S713).

[0188] FIG. 8 is a diagram illustrating a wireless charging method in a wireless power transmitter according to another embodiment. FIG. 9 is a diagram for explaining a method for detecting foreign matter according to a peak frequency value.

[0189] Referring to FIG. 8, the wireless charging method in the wireless power transmitter is a peak before the ping stage. The method may include measuring a frequency value (S901). In the selection step, the peak frequency value of the transmission power can be measured using the sensing unit. .

[0190] The wireless charging method in the wireless power transmitter includes an FOD status packet including a reference peak frequency value. In one example, the wireless power transmitter may receive a negotiation request (S902). In this step, the FOD status packet can be received using the communication unit. The value may be the peak frequency value of the received power stored in the wireless power receiver.

[0191] The wireless charging method in the wireless power transmitter includes the step of determining a critical peak frequency value (S90 3) can be included. More specifically, the wireless power transmitter can include: The numerical values ​​can be used to calculate the critical peak frequency value. The machine determines the critical peak frequency value as a value that is 10% higher than the reference peak frequency value. 10% is the tolerance for the reference peak frequency value, and if there is a foreign substance, The measured peak frequency value must be greater than the reference peak frequency value by at least the allowable error. It can be used to detect foreign substances.

[0192] The wireless charging method for the wireless power transmitter includes the step of determining an allowable peak frequency value (S90 4) More specifically, the wireless power transmitter may include: The allowable peak frequency value can be calculated using the wave number value. For example, as shown in Figure 9, In addition, the wireless power transmitter should be designed to increase the critical peak frequency (Fth) by 0% or more and 20% or less. The value obtained can be determined as the allowable peak frequency value (fp). For power transmitters, the allowable peak frequency value is 20% above the critical peak frequency value. This can be determined.

[0193] The wireless charging method in the wireless power transmitter is to measure the peak frequency value and determine the allowable peak frequency. The step of determining whether the frequency is equal to or less than the peak frequency value (S905) may be included.

[0194] The wireless power transmitter will perform wireless charging if the peak frequency value is below the allowable peak frequency value. The wireless power transmitter may determine that the peak frequency value is within the allowable peak value (S906). If the frequency value is exceeded, it may be determined to stop wireless charging (S914). 9, the wireless power transmitter determines whether the measured peak frequency is a first peak frequency value (f1), a second peak frequency value (f2), or a third peak frequency value (f3). The first peak frequency may be a second peak frequency value (f2), a third peak frequency value (f3), or the like. If the value is measured as (f1), there is a foreign object between the wireless power transmitter and the wireless power receiver. Since the probability of this not occurring is very high, it can be concluded that no foreign substances are present. If the frequency value (f3) is measured, the third peak frequency value (f3) is the critical peak frequency Since it is much higher than the value (Fth), there is a foreign object between the wireless power transmitter and the wireless power receiver. Since the probability of this occurring is very high, it can be determined that a foreign substance is present. If the second peak frequency value (f2) is measured to be the critical peak frequency value (Q th) and the allowable peak frequency value (fp), so the To prevent this, the wireless power transmitter If the measured peak frequency value is equal to or greater than the allowable peak frequency value, wireless charging is permitted. After that, the wireless power transmitter performs the second foreign object detection in the power transmission step S911. Therefore, it is possible to more accurately determine whether or not a foreign substance is present. The device may determine to perform wireless charging if the peak frequency value is equal to or less than the allowable peak frequency value. This allows another embodiment to accurately determine whether a foreign substance is present. In another embodiment, the foreign substance is accurately detected, and the heat generation phenomenon, the decrease in charging efficiency phenomenon, and the power consumption are eliminated. In another embodiment, the present invention can prevent wasteful use of the substance. This solves the problem of wireless charging not working.

[0195] When the wireless power transmitter decides to perform wireless charging, it responds to the FOD status packet reception. In response, an ACK packet can be transmitted to the wireless power receiver (S907).

[0196] The wireless charging method in the wireless power transmitter is such that the peak frequency value of the wireless power transmitter is equal to or exceeds the critical peak. The method may further include determining whether the frequency is equal to or less than the threshold frequency (S908). In the negotiation stage, the wireless power transmitter decides to perform wireless charging, then moves to the correction stage. To determine whether to perform a correction, the peak frequency value is checked to see if it is below the critical peak frequency value. It is possible to make a judgment.

[0197] The wireless charging method in the wireless power transmitter is such that the peak frequency value of the wireless power transmitter is equal to or exceeds the critical peak. If the frequency is equal to or less than the threshold frequency, the step of performing the correction is performed (S909). As an example, the correction can be performed by the wireless power transmitter receiving the received power packet. The power loss can be predicted using the received power value of the device and the measured transmitted power value. ,The correction execution is performed by the wireless power transmitter ,using the predicted power loss value to increase the intensity of the ,transmission power. It can be done.

[0198] The wireless charging method in the wireless power transmitter is such that the peak frequency value of the wireless power transmitter is equal to or exceeds the critical peak. If the frequency exceeds the threshold, the power transfer step (S910) can be performed without the correction step.

[0199] The wireless charging method in the wireless power transmitter is a method of receiving a power packet after entering a power transmission stage. If the power supply voltage is received, the method may include performing a second foreign substance detection (S911). The device will perform a second foreign substance detection and stop wireless charging if it determines that a foreign substance has been detected. In addition, the wireless power transmitter can perform a second foreign substance detection (S912, S913). If it is determined that no foreign matter is detected, the power transmission stage can be maintained and the receiving If the received power packet is received, the second foreign substance detection can be performed again (S912, S9 11). For example, in the power transmission stage, the wireless power transmitter The power loss is determined using the power value, which is a numerical value, and the measured transmission power value, and the The wireless power transmitter can detect whether or not a foreign object is present by measuring the power loss value. If a predetermined critical power loss value is exceeded, it can be determined that a foreign substance is present. , the wireless power transmitter sends a NAK in response to the received power packet to stop charging. The packet can be sent to the wireless power receiver. Then, the wireless power transmitter can As another example, the wireless power transmitter may stop receiving the received power packet. Detect whether or not a foreign substance is present by using the internal temperature value measured regardless of whether or not it is present. That is, if the internal temperature exceeds a predetermined critical temperature, it is determined that a foreign substance is present. In this case, the wireless power transmitter can stop wireless charging. Therefore, in another embodiment, even if foreign matter is suspected during the negotiation stage, wireless charging is not stopped and the device is not used. After line charging, foreign matter is detected again at the power transmission stage to determine whether or not foreign matter is present. can be judged accurately.

[0200] When the wireless power transmitter determines to stop wireless charging in S914, it sends an FOD status packet A NAK packet can be sent to the wireless power receiver in response to the reception (S9 15) After that, the wireless power transmitter can stop wireless charging (S913).

[0201] FIG. 10 is a diagram illustrating a wireless charging method in a wireless power transmitter according to yet another embodiment. FIG. 11 is a diagram for explaining a method for detecting foreign matter according to an equivalent series resistance value. is.

[0202] Referring to FIG. 10, the wireless charging method in the wireless power transmitter is equivalent to the ping step. The method may include measuring a series resistance (S1101). The device can measure the equivalent series resistance value using the sensing unit in the selection step.

[0203] The wireless charging method in the wireless power transmitter is a F The method may include receiving an OD status packet (S1102). The power transmitter can receive FOD status packets using the communication unit during the negotiation phase. The reference Q value and reference peak frequency value are the Q value and peak frequency value stored in the wireless power receiver. It's okay to have one.

[0204] The wireless charging method for the wireless power transmitter includes a step of determining a critical equivalent series resistance (S11 03). More specifically, the wireless power transmitter may include a received reference Q value and The reference peak frequency value can be used to determine the reference equivalent series resistance value. In other words, the reference equivalent series resistance (ESRr) is the reference peak frequency (fr), the reference Q value (Qr) The reference inductance value (Lr) can be calculated by substituting the reference inductance value (Lr) into Equation 2. For reference, the reference inductance value (Lr) is the fixed capacitance of the wireless power receiver. The peak frequency (Cr) can be determined using the received reference peak frequency (fr).

[0205] (Equation 2) TIFF2025143356000003.tif2460(Formula 3) TIFF2025143356000004.tif2556 For example, a wireless power transmitter may set a critical value that is 10% higher than the reference equivalent series resistance. It can be determined as the equivalent series resistance (ESRth). The maximum value of the reference equivalent series resistance (ESRmax) is set as the critical equivalent series resistance (ESRth). 10% is the tolerance of the reference equivalent series resistance value, and it can be determined by the presence of foreign matter. When the measured equivalent series resistance is greater than the reference equivalent series resistance by at least the allowable error, This can be used to detect foreign substances.

[0206] The wireless charging method for the wireless power transmitter includes the step of determining an allowable equivalent series resistance (S11 04). More specifically, the wireless power transmitter may include a determined critical equivalent current. The allowable equivalent series resistance can be calculated using the column resistance. Therefore, the wireless power transmitter must have a critical equivalent series resistance (ESRth) of 0% to 20%. The lower increased value can be determined as the allowable equivalent series resistance (ESRp). Specifically, the wireless power transmitter tolerates a 20% increase in the critical equivalent series resistance. It can be determined as a series resistance.

[0207] The wireless charging method for the wireless power transmitter is to determine the tolerance of the measured equivalent series resistance. The step of determining whether the resistance is equal to or less than the valence series resistance (S1105) may be included.

[0208] The wireless power transmitter performs wireless charging if the equivalent series resistance is equal to or less than the allowable equivalent series resistance. The wireless power transmitter can determine whether the equivalent series resistance is within the allowable range (S1106). If the series resistance value is exceeded, it may be determined to stop wireless charging (S1114). ,As shown in FIG. 11, the wireless power transmitter,measured equivalent series resistance value is the first equivalent series resistance value ( ESR1), the second equivalent series resistance (ESR2), and the third equivalent series resistance (ESR3) If the first equivalent series resistance (ESR1) is measured, the wireless power transmitter and Since there is a very high probability that no foreign matter exists between the input and receiver, it is judged that no foreign matter exists. If the third equivalent series resistance (ESR3) is measured, the third equivalent series The resistance value (ESR3) is much higher than the critical equivalent series resistance (ESRth), so wireless power transmission There is a very high probability that foreign objects exist between the device and the wireless power receiver. If the second equivalent series resistance (ESR2) is measured, it can be determined that the The equivalent series resistance (ESR2) is calculated by dividing the critical equivalent series resistance (ESRth) by the allowable equivalent series resistance (ES Rp), it is mistakenly assumed that there is a foreign object between the wireless power transmitter and the wireless power receiver. To prevent this, the wireless power transmitter uses the measured equivalent series resistance If the value is equal to or greater than the allowable equivalent series resistance, wireless charging can be performed. The receiver performs a second foreign substance detection during the power transmission stage of S1111 to more accurately detect the presence of foreign substances. Therefore, the wireless power transmitter can determine whether the equivalent series resistance is acceptable. If the equivalent series resistance is equal to or less than the allowable equivalent series resistance, it can be determined that wireless charging is to be performed. In yet another embodiment, foreign substances can be accurately determined. Accurately detects foreign substances to prevent heat generation, reduced charging efficiency, and wasted power consumption Furthermore, in still another embodiment, a conventional method for detecting the presence of a foreign substance by mistake can be used. This can solve the problem of no charging.

[0209] When the wireless power transmitter decides to perform wireless charging, it responds to the FOD status packet reception. In response, an ACK packet can be transmitted to the wireless power receiver (S1107).

[0210] The wireless charging method for the wireless power transmitter is to The method may further include determining whether the resistance is equal to or less than the series resistance value (S1108). In the example, the wireless power transmitter determines to perform wireless charging in the negotiation stage, and then transitions to the correction stage. Whether the equivalent series resistance is less than the critical equivalent series resistance to determine whether correction should be performed It is possible to determine the following.

[0211] The wireless charging method for the wireless power transmitter is to If the resistance is equal to or less than the series resistance value, the step of transitioning to a correction step and performing the correction (S1109) may be included. As an example, the correction can be performed by the wireless power transmitter adjusting the wireless power reception of the received power packet. The power loss can be predicted by using the received power value of the receiver and the measured transmitted power value. In addition, the correction execution is performed by the wireless power transmitter increasing the strength of the transmission power using the predicted power loss value. It can be added.

[0212] The wireless charging method for the wireless power transmitter is to If the series resistance value is exceeded, the power transfer step (S910) can be entered without a correction step.

[0213] The wireless charging method in the wireless power transmitter is a method of receiving a power packet after entering a power transmission stage. If the signal is received, the method may include a step of detecting a second foreign substance (S1111). The receiver performs a second foreign substance detection and stops wireless charging if it determines that a foreign substance has been detected. In addition, the wireless power transmitter can detect a second foreign object (S1112, S1113). If it is determined that no foreign matter is detected, the power transfer stage can be maintained. If the received power packet is received, the second foreign substance detection can be performed again (S111 2, S1111). For example, in the power transmission stage, the wireless power transmitter receives the received power The power value, which is the number of packets, and the measured transmission power value are used to determine the power loss. The presence or absence of a foreign substance can be detected based on the error value. If the power loss value exceeds a predetermined critical power loss value, it can be determined that a foreign substance is present. In this case, the wireless power transmitter sends a response to the received power packet to stop charging. Then, the wireless power transmitter can send a NAK packet to the wireless power receiver. As another example, the wireless power transmitter may receive a power packet and then stop wireless charging. Whether or not a foreign object is present is determined using the internal temperature measured regardless of whether or not a signal is received. That is, if the internal temperature exceeds a predetermined critical temperature, it is determined that a foreign substance exists. In this case, the wireless power transmitter can stop wireless charging. Therefore, in a further embodiment, even if foreign matter is suspected to be detected during the negotiation stage, wireless If there is a foreign object, the device will continue wireless charging without stopping charging and then detect the foreign object again during the power transmission stage. You can accurately determine whether or not to do so.

[0214] When the wireless power transmitter decides to stop wireless charging in S1114, it sends an FOD status packet. A NAK packet can be sent to the wireless power receiver in response to the received packet (S 1115). After that, the wireless power transmitter can stop wireless charging (S1113).

[0215] 12a and 12b show a wireless charging system in a wireless power transmitter according to yet another embodiment. 1 is a diagram for explaining a method.

[0216] Referring to FIG. 12a and FIG. 12b, the wireless charging method in the wireless power transmitter is Before the step of measuring, a step (S1201) of measuring a Q value, a peak frequency value, and an equivalent series resistance value is performed. As an example, the wireless power transmitter may include: The Q value, peak frequency value and equivalent series resistance value can be measured.

[0217] The wireless charging method in the wireless power transmitter is a FOD condition including a reference Q value and a reference frequency value. The method may include receiving a status packet (S1202). The device can receive FOD status packets using the communication unit during the negotiation phase. The Q value and the reference peak frequency value are the Q value and the peak frequency value stored in the wireless power receiver. Good too.

[0218] The wireless charging method for wireless power transmitters requires the critical Q value, critical frequency value, and critical equivalent series resistance. The wireless power transmitter may include a step of determining a value (S1203). The critical Q value can be calculated using the received reference Q value. The transmitter may determine the critical Q value to be a value that is 10% less than the reference Q value. 10% is the tolerance for the standard Q value. If there is a foreign substance, the measurement must be at least equal to the tolerance. Foreign substances can be detected by utilizing the fact that the Q value is smaller than the reference Q value. The line power transmitter may use the received reference frequency value to calculate the critical peak frequency value. As an example, a wireless power transmitter may set a 10% increase in the reference frequency value as the critical value. The frequency value can be determined as 10%. The tolerance of the reference peak frequency value is If there is foreign matter, the measured peak frequency value must be at least equal to the reference peak frequency value. The larger size can be used to detect foreign objects. , determining a reference equivalent series resistance value using the received reference Q value and reference peak frequency value; As an example, a wireless power transmitter may be designed to have a 10% increase in reference equivalent series resistance. The value obtained can be determined as the critical equivalent series resistance (ESRth). The wireless power transmitter sets the maximum value of the reference equivalent series resistance (ESRmax) to the critical equivalent series resistance (E SRth) where 10% is the tolerance of the reference equivalent series resistance. If there is a foreign substance, the measured equivalent series resistance is at least equal to the tolerance. Foreign substances can be detected by utilizing the fact that the value is greater than the threshold value.

[0219] The wireless charging method for wireless power transmitters requires the following: allowable Q value, allowable frequency value, allowable equivalent series resistance The wireless power transmitter may include a step of determining a value (S1204). The allowable Q value can be calculated using the critical Q value determined in step S704 of FIG. 6. In addition, the wireless power transmitter determines the critical peak frequency value determined in step S904 of FIG. The allowable peak frequency value can be calculated using the above. The allowable equivalent series resistance is calculated using the critical equivalent series resistance determined as in S1104. It can be put out.

[0220] The wireless charging method for the wireless power transmitter is to ensure that the measured Q value is equal to or greater than the determined allowable Q value. The wireless power transmitter may include a step of determining whether the Q value is acceptable (S1205). If the value is not equal to or greater than the Q value, it may be determined to stop wireless charging (S1218).

[0221] The wireless charging method for wireless power transmitters is equivalent to the measured value if the Q value is greater than or equal to the allowable Q value. Step S1206: determining whether the series resistance is equal to or less than the determined allowable equivalent series resistance. The wireless power transmitter may include a If not, it may be determined to stop wireless charging (S1218).

[0222] The wireless charging method for wireless power transmitters requires that the equivalent series resistance is below the allowable equivalent series resistance. If so, determine whether the measured peak frequency is equal to or less than the determined allowable peak frequency. The wireless power transmitter may include a step of: If the frequency is not equal to or less than the peak frequency value, it may be determined to stop wireless charging (S121 8).

[0223] The wireless charging method for wireless power transmitters is to ensure that the peak frequency is below the allowable peak frequency. If there is a wireless power supply, it can determine to perform wireless charging (S1208). Although the measurement value used for detecting foreign matter may not reach the critical value that is the standard for wireless charging, Once the capacity is reached, it can decide to perform wireless charging. In one embodiment, the foreign substance can be accurately determined. Accurately judge the temperature and prevent heat generation, reduced charging efficiency, and wasteful power consumption. Furthermore, in still another embodiment, a device that has been conventionally erroneously recognized as having a foreign substance and wireless charging has been performed is provided. No problem can be solved.

[0224] When the wireless power transmitter decides to perform wireless charging, it responds to the FOD status packet reception. In response, an ACK packet can be transmitted to the wireless power receiver (S1209).

[0225] The wireless charging method for the wireless power transmitter is such that the Q value of the wireless power transmitter is equal to or greater than the critical Q value. The wireless power transmitter may include a step of determining whether the wireless power transmitter is configured to transmit wireless power. If the Q value of the device is not equal to or greater than the critical Q value, the device will proceed to the power transmission stage (S1214) without the correction stage. It is possible.

[0226] The wireless charging method for wireless power transmitters is as follows: if the Q value is greater than or equal to the critical Q value, The machine performs a step (S1211) of determining whether the equivalent series resistance is equal to or greater than the critical equivalent series resistance. The wireless power transmitter may include a power supply having an equivalent series resistance not less than a critical equivalent series resistance. If not, the process can proceed to the power transmission step (S1214) without the correction step.

[0227] The wireless charging method for wireless power transmitters requires that the equivalent series resistance is less than the critical equivalent series resistance. If so, the wireless power transmitter determines whether the peak frequency value is equal to or greater than the critical peak frequency value. The wireless power transmitter may include a step of transmitting a power to a power supply when the wireless power transmitter detects a peak frequency. If the wave number value is not less than the critical peak frequency value, the power transmission step (S121) is performed without the correction step. 4) can be transitioned to.

[0228] The wireless charging method in the wireless power transmitter is such that the peak frequency value of the wireless power transmitter is equal to or exceeds the critical peak. If the frequency is equal to or less than the threshold frequency value, the step of transitioning to a correction step and performing correction (S1213) may be included. This can be done.

[0229] The wireless charging method in the wireless power transmitter is a method of receiving a power packet after entering a power transmission stage. If the signal is received, the method may include a step of detecting a second foreign substance (S1215). The receiver performs a second foreign substance detection and stops wireless charging if it determines that a foreign substance has been detected. In addition, the wireless power transmitter can detect a second foreign object (S1216, S1217). If it is determined that no foreign matter is detected, the power transfer stage can be maintained. If the received power packet is received, the second foreign substance detection can be performed again (S121 6, S1215). For example, in the power transmission stage, the wireless power transmitter receives the received power The power value, which is the number of packets, and the measured transmission power value are used to determine the power loss. The presence or absence of a foreign substance can be detected based on the error value. If the power loss value exceeds a predetermined critical power loss value, it can be determined that a foreign substance is present. In this case, the wireless power transmitter sends a response to the received power packet to stop charging. Then, the wireless power transmitter can send a NAK packet to the wireless power receiver. As another example, the wireless power transmitter may receive a power packet and then stop wireless charging. Whether or not a foreign object is present is determined using the internal temperature measured regardless of whether or not a signal is received. That is, if the internal temperature exceeds a predetermined critical temperature, it is determined that a foreign substance exists. In this case, the wireless power transmitter can stop wireless charging. Therefore, another embodiment allows wireless charging to be performed even if foreign matter is suspected during the negotiation stage. If a foreign object is detected during the power transmission stage after wireless charging is continued without interruption, It can be accurately determined whether or not

[0230] When the wireless power transmitter decides to stop wireless charging in S1218, it sends an FOD status packet. A NAK packet can be sent to the wireless power receiver in response to the received packet (S 1219). After that, the wireless power transmitter can stop wireless charging (S1217).

[0231] FIG. 13 illustrates a wireless charging method in a wireless charging system according to yet another embodiment. This is a drawing for

[0232] Referring to FIG. 13, the wireless power transmitter 1310 selects the wireless power receiver 1320. An analog ping can be transmitted to the mobile station (S1301).

[0233] The wireless power transmitter 1310 can measure the Q factor before the ping stage (S130 2). As an example, the wireless power transmitter 1310 can measure the Q factor during the selection stage ( S1302).

[0234] The wireless power transmitter 1310 transitions from the selection phase to the ping phase when an object is detected. The wireless power transmitter 1310 activates the wireless power receiver 1320 and receives Transmitting a digital ping to identify the device as a wireless power receiver 1320 In response to the digital ping, the wireless power receiver 1320 A signal strength packet can be transmitted (S1304).

[0235] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 1320 receives the identification information The identification packet for informing the information and the configuration packet for informing the configuration information are transmitted. (S1305 to S1306). 0 if the negotiation field value in the configuration packet indicates that the negotiation phase is to be performed You can move to the negotiation stage.

[0236] During the negotiation phase, the wireless power receiver 1320 sends an FOD status packet to detect the FOD. The FOD status packet may include a reference Q value. do.

[0237] The wireless power transmitter 1310 may perform foreign substance detection (S1308). detects foreign substances using the measured Q value and the information of the received FOD status packet. For foreign object detection, please refer to the description of the wireless charging method in Figures 14a and 15a. do.

[0238] If the wireless power transmitter 1310 determines that a foreign substance is present after detecting the foreign substance, A NAK may be transmitted to the wireless power receiver 1320 in response to the OD status packet. On the other hand, the wireless power transmitter 1310 detects the foreign matter and then determines whether the foreign matter is present (S1309). If it determines that it does not exist, it sends an ACK in response to the FOD status packet. The data can be transmitted to the device 1320.

[0239] When the wireless power transmitter 1310 transmits a NAK, it determines whether to perform wireless charging. The determination of whether to perform wireless charging is based on the measured Q value, the received The information in the FOD status packet can be used to determine whether to perform wireless charging. Please refer to the description of the wireless charging method in Figures 14a and 15b.

[0240] The wireless power receiver 1320 receives a power transmission capability packet for a power transmission contract. A general request packet can be transmitted to request a packet (S1311).

[0241] If the wireless power transmitter 1320 determines to perform wireless charging after transmitting NAK, In response to the request packet, the power transmitter can transmit a power packet (S1312). In this case, the guaranteed power of the power transmission function power packet is the second guaranteed power value. On the other hand, if the wireless power transmitter 1320 transmits ACK in S1309, the power transmission The guaranteed power of the functional power packet may be a first guaranteed power value. The first guaranteed power value may be greater than the second guaranteed power value. In particular, the second guaranteed power value may be greater than the It may be the minimum guaranteed power strength of the line power transmitter 1310. As another example, the first guaranteed power The second guaranteed power value may be 5 W or more and 15 W or less. .

[0242] The wireless power receiver 1320 transmits the power based on the second guaranteed power value of the power transmission packet. A special request packet can be transmitted to propose a guaranteed power value for the power transmission contract ( S1313). It should be noted that the second guaranteed power and power transmission of the power packet The contracted guaranteed power is distinguished. For example, the wireless power receiver 1320 The guaranteed power value of the power transmission contract is the same as or smaller than the second guaranteed power value of the transmission function power packet. For convenience of explanation, the wireless power receiver 1320 may be configured to transmit power. The guaranteed power value in the transmission contract is requested to be the same as the second guaranteed power value in the power transmission function power packet. The line power transmitter 1310 sends a special request packet to request the guaranteed power value of the power transmission contract. In response to the received packet, an ACK packet can be transmitted (S1314). The power transmitter 1310 accepts the guaranteed power value of the power transmission contract proposed by the wireless power receiver. In other words, the power transmission contract can be completed at the second guaranteed power value. , the wireless power receiver 1320 performs a negotiation to end the negotiation phase once the power transfer agreement is completed. The wireless power transmitter 1310 can transmit a special request packet (S1315). Transmitting an ACK packet in response to a special request packet to terminate the negotiation phase That is, the wireless power transmitter 1310 can receive the reception signal for the end of the negotiation phase (S1316). An ACK packet can be transmitted as an acknowledgment.

[0243] After the wireless power transmitter 1310 has entered the power transmission stage, the wireless power transmitter 1310 In particular, the wireless power transmitter 1310 can measure the internal temperature of the If a NAK is sent in response to an FOD status packet during the negotiation phase, the It is possible to transition to the power transfer phase rather than the forward phase.

[0244] The wireless power transmitter 1310 can determine whether to increase the transmission power strength. The decision to increase the transmission power intensity is based on the measured internal temperature, the stored preset temperature, and the The transmission power intensity increase decision can be made using a predetermined time period and a preset temperature. 14b for the wireless charging method. If a decision is made to increase the level, a renegotiation step can be performed. The power receiver 1320 can transmit the received power packet to the wireless power transmitter 1310. In this case, the received power packet is a 24-bit received power packet. When the wireless power transmitter 1310 determines to increase the transmission power strength, it may In response to the packet, a NAK packet can be transmitted (S1320). , the wireless power transmitter 1310 receives the renegotiation packet and accepts the transition to the renegotiation phase. The wireless power receiver 13 can transmit an ACK packet (S1321 to S1322). 20 can transmit a general request packet requesting a power transmission function power packet ( S1323). The wireless power transmitter 1310 transmits the power transmission function in response to the general request packet. In this case, the power transmitting function can transmit the power packet (S1324). The guaranteed power may be a third guaranteed power value. As another example, the third guaranteed power value may be greater than or equal to 5 W and less than or equal to 15 W. The wireless power receiver 1320 may determine whether the power transmission function is capable of transmitting power based on the third guaranteed power value of the power packet. Based on this, a special request packet is transmitted to propose a guaranteed power value for the power transmission contract. It is important to note that the power transmission function is The guaranteed power of the transmission contract is different. For example, the wireless power receiver 1320 The power transmission function guarantees the power transmission contract with a value equal to or smaller than the third guaranteed power value of the power packet. For convenience of explanation, the wireless power receiver 1320 may propose a power - The guaranteed power value of the transmission contract is proposed to be the same as the third guaranteed power value of the power transmission function packet. The wireless power transmitter 1310 receives a special request parameter to propose a guaranteed power value for the power transmission contract. In response to the ACK packet, an ACK packet can be transmitted (S1326). The wireless power transmitter 1310 receives the guaranteed power value of the power transmission contract proposed by the wireless power receiver. That is, the power transmission contract can be completed at the third guaranteed power value. Thereafter, the wireless power receiver 1320 ends the renegotiation phase when the power transfer agreement is completed. The wireless power transmitter 1310 may transmit a special request packet for the wireless power transmitter 1310 (S1327). sends an ACK packet in response to a special request packet to terminate the renegotiation phase. That is, the wireless power transmitter 1310 can transmit the The wireless power transmitter 1310 can transmit an ACK packet as an acknowledgement to the wireless power transmitter 1310. The line power receiver 1320 transitions to the power transmission stage and performs wireless charging at the third guaranteed power. This can be done.

[0245] Therefore, the wireless charging system according to the embodiment includes a wireless charging method and an apparatus therefor, and In addition, the wireless charging system according to the embodiment can provide a system for properly charging foreign substances. In addition, the wireless charging system according to the embodiment can accurately determine whether a foreign substance is present or not. As a result, heat generation, reduced charging efficiency, and wasted power consumption can be prevented.

[0246] 14a and 14b are diagrams illustrating a wireless power transmitter according to another embodiment of the present invention; 15a is a diagram illustrating a wireless charging method, and FIG. 15a is a diagram illustrating a foreign object in the wireless charging method of FIG. 14a. 15b is a diagram illustrating a quality detection method of the wireless charging method of FIG. 14a. 10 is a diagram illustrating a method for determining whether to perform power supply.

[0247] Referring to FIG. 14a and FIG. 14b, the wireless charging method in the wireless power transmitter is The method may include detecting an object in a region (S1401). The transmitter sends analog pings to sense objects based on changes in current in the transmit coil. This can be done.

[0248] The wireless charging method in the wireless power transmitter includes a step of measuring a Q value (S1 402). In one example, the wireless power transmitter may include a sensing unit in the selection step. The Q value can be measured using

[0249] The wireless charging method in the wireless power transmitter includes the step of receiving information including a reference Q value (S14 03). More specifically, the wireless power transmitter may include a FOD including a reference Q value. A status packet can be received.

[0250] The wireless charging method in the wireless power transmitter uses the measured Q value and the reference Q value to The method may include steps of detecting a substance (S1404 to S1405). As in a, the step of detecting foreign matter may include a step of determining a critical Q value (S1511). More specifically, the wireless power transmitter calculates the critical Q value using the received reference Q value. The wireless power transmitter should have a reference Q value of at least 10% lower. can be determined as the critical Q value. 10% is the tolerance for the reference Q value, and If there is a problem, the measured Q value will be smaller than the reference Q value by at least the allowable error. In addition, the foreign substance detection step is performed when the measured Q value is equal to or greater than the critical Q value. The wireless power transmitter may include a step of determining whether the power supply is above the power supply voltage (S1512). If the detected Q value is equal to or greater than the critical Q value, it can be determined that no foreign matter has been detected. (S1513). In addition, if the measured Q value is less than the critical Q value, the wireless power transmitter detects the presence of a foreign object. It can be determined that quality has been detected (S1514).

[0251] If the wireless charging method in the wireless power transmitter determines that no foreign matter is detected, The wireless power transmitter can transmit the CK to the wireless power receiver (S1406). Send an ACK packet to the wireless power receiver in response to receiving the FOD status packet. It is possible.

[0252] In the wireless charging method in the wireless power transmitter, if an ACK is sent, the first guaranteed power value is included. The method may include transmitting the information to a wireless power transmitter (S1407). The power transmitter and the wireless power receiver enter into a power transmission contract based on the first guaranteed power value. As an example, the first guaranteed power value may be greater than 5W.

[0253] In the wireless charging method for the wireless power transmitter, when information including a first guaranteed power value is transmitted, The method may include a step of transitioning to a correction step and performing correction (S1408). In the correct execution, the wireless power transmitter measures the received power value of the wireless power receiver in the received power packet. The transmission power value can be used to predict power loss. The transmitter can use the predicted power loss value to increase the strength of the transmission power.

[0254] The wireless charging method in the wireless power transmitter performs correction and then transitions to the power transmission stage to achieve the first guarantee. In this case, the first guaranteed power may be used for wireless charging (S1409). Wireless charging is guaranteed by the power transmission contract concluded based on the first guaranteed power value. This may mean performing wireless charging according to a power value.

[0255] In the wireless charging method for the wireless power transmitter, it is determined that a foreign substance is detected in step S1405. Then, the NAK can be transmitted to the wireless power receiver (S1410). The device sends a NAK packet to the wireless power receiver in response to receiving the FOD status packet. It can be trusted.

[0256] The wireless charging method in the wireless power transmitter determines whether to perform wireless charging when it sends NAK. For example, the step of determining whether the Thus, the step of determining whether to perform wireless charging is the step of determining the allowable Q value (S15 21). More specifically, the wireless power transmitter may include: As an example, as shown in Figure 7, The allowable Q value (Qp) is the value that is reduced by 0% or more and 20% or less from the critical Q value (Qth). More specifically, the wireless power transmitter can be determined to have a 20% reduction in critical Q value. The value can be determined as the allowable Q value. The decision on whether to perform wireless charging is based on the measurement. and determining whether the determined Q value is equal to or greater than the determined allowable Q value (S1522). If the measured Q value of the wireless power transmitter is equal to or greater than the allowable Q value, wireless charging will be performed. In addition, the wireless power transmitter determines whether the measured Q value is within the allowable Q value (S1523). If the battery voltage is less than 100V, it can be determined that wireless charging is not to be performed (S1524). As shown, when the frequency of the transmission power is the first frequency, the wireless power transmitter measures the Q value as It may be a first Q value (Q1), a second Q value (Q2), or a third Q value (Q3). If it is measured that there is no foreign object between the wireless power transmitter and the wireless power receiver, Since it is so high, it can be determined that no foreign matter is present. When measured, the third Q value (Q3) is much lower than the critical Q value (Qth), so wireless power transmission There is a very high probability that foreign objects exist between the device and the wireless power receiver. If the second Q value (Q2) is measured, the second Q value (Q2) is considered to be critical. Since it is between the Q value (Qth) and the allowable Q value (Qp), To prevent this, the wireless power transmitter must: If the measured Q value is equal to or greater than the allowable Q value, wireless charging can be performed. The transmitter can re-judge whether to stop wireless charging based on the internal temperature in S1417. Therefore, the wireless power transmitter performs wireless charging if the Q value is equal to or greater than the allowable Q value. Thus, in yet another embodiment, the foreign substance can be accurately determined. In addition, in still another embodiment, the foreign substance can be accurately determined and the heat generation phenomenon, the charging efficiency, etc. This can prevent the phenomenon of reduced power consumption and waste of power. This solves the problem of wireless charging not being performed due to the device being mistakenly recognized as having a foreign substance.

[0257] The wireless charging method in the wireless power transmitter determines that the wireless power transmitter does not perform wireless charging. If so, the step of stopping wireless charging (S1413) may be included. In this case, the wireless power transmitter will move to the selection phase after a predetermined time has elapsed in the negotiation phase. can be done.

[0258] The wireless charging method in the wireless power transmitter includes: The method may include transmitting information including the value to the wireless power receiver (S1414). In this case, the wireless power transmitter and the wireless power receiver establish a power transmission agreement based on the second guaranteed power value. As an example, the first guaranteed power value may be greater than the second guaranteed power value. The second guaranteed power value may be the minimum guaranteed power intensity of the wireless power transmitter. The second guaranteed power value may be 5W or less.

[0259] In the wireless charging method in the wireless power transmitter, when information including the second guaranteed power value is transmitted, If so, the step of transitioning to the power transmission step without the correction step and wirelessly charging with the second guaranteed power (S14 In this case, wireless charging at the second guaranteed power may include the second guaranteed power. Wireless charging is performed according to the guaranteed power value in the power transmission contract concluded based on the power value. It can mean:

[0260] The following is a summary of the process of detecting foreign matter before the power transmission stage and the process of detecting foreign matter during the power transmission stage. When it is determined that a foreign substance is present, the foreign substance generates heat. Further overheating may occur, so overheat protection measures must be strengthened. Since there is a possibility that the amount of power absorbed by the material is large, the receiver receives a preset power loss value. The difference between the received power and the transmitted power can be compared to detect foreign matter. The determined power loss value may be smaller than the critical power loss value in the absence of foreign matter. good.

[0261] Due to the enhanced overheat protection, the wireless charging method in the wireless power transmitter is The method may include measuring the temperature of the wireless power transmitter, such as the area (S1416). The temperature may refer to a surface temperature or a temperature sensed by a sensor in the transmitter.

[0262] The wireless charging method in the wireless power transmitter is such that the internal temperature measured for a predetermined period of time is The method may include determining whether the temperature is lower than a preset temperature (S1417). The preset time period and preset temperature may be stored values.

[0263] The wireless charging method in the wireless power transmitter is to keep the internal temperature at a predetermined value for a predetermined period of time. If the temperature reaches or exceeds the predetermined temperature, the step of stopping wireless charging (S1418) may be included. Specifically, in this case, the wireless power transmitter selects the power source after a predetermined time has elapsed during the power transmission stage. That is, the wireless power transmitter can move to the internal selection stage for a preset period. If the temperature exceeds a preset level, it will determine that a foreign object is present and stop wireless charging. Or, renegotiation can be performed to lower the transmission power. The wireless power transmitter then sends a NAK packet in response to the received power packet. The wireless power transmitter then transmits a renegotiation packet to the wireless power receiver. That is, the wireless power transmitter can transmit the preset If the internal temperature is above a preset temperature during this period, it is determined that a foreign substance is present and transmission The power intensity can be reduced.

[0264] The wireless charging method in the wireless power transmitter is to keep the internal temperature at a predetermined value for a predetermined period of time. If the temperature is lower than the predetermined temperature, a renegotiation step (S1419) may be performed. As a result, the wireless power transmitter sends a NAK packet in response to a received power packet. The wireless power transmitter then sends a renegotiation packet to the wireless power receiver. In other words, the wireless power transmitter can transmit the preset If the internal temperature remains below a preset temperature for the specified period, it is determined that no foreign matter is present. The transmitted power intensity can be increased.

[0265] When the wireless charging method in the wireless power transmitter enters the renegotiation stage, the third guaranteed power value is In this case, the method may include transmitting information including: The wireless power transmitter and the wireless power receiver enter into a power transmission contract based on the third guaranteed power value. As an example, the third guaranteed power value may be greater than the second guaranteed power value. The third guaranteed power value may be greater than 5W.

[0266] The wireless charging method in the wireless power transmitter is to move to the power transmission stage and wirelessly charge with the third guaranteed power. In this case, the wireless charging may be performed at the third guaranteed power. The purpose of this is to comply with the guaranteed power value in the power transmission contract concluded based on the third guaranteed power value. This means that the wireless power transmitter can exchange In the interference stage, it determines that a foreign substance has been detected and reduces the transmission power strength to protect the system. At the power transmission stage, it is determined that no foreign matter is detected and the transmission power strength is increased to The line charging efficiency can be increased.

[0267] In yet another embodiment, in the NAK transmission step (S1410), the wireless power receiver can request the transmitter to provide the minimum power required to charge the battery (negotiating stage) floor).

[0268] In addition, if the receiver determines that there is no foreign matter after a certain period of time has passed, it will renegotiate The guaranteed power can also be increased.

[0269] FIG. 16 illustrates a wireless charging method in a wireless charging system according to yet another embodiment. This is a drawing for

[0270] Referring to FIG. 16, a wireless power transmitter 1610 selects a wireless power receiver 1620. An analog ping can be transmitted to the (S1601).

[0271] The wireless power transmitter 1610 can measure the Q factor before the ping stage (S160 2). As an example, the wireless power transmitter 1610 can measure the Q factor during the selection stage ( S1602).

[0272] The wireless power transmitter 1610 transitions from the selection phase to the ping phase when an object is detected. The wireless power transmitter 1610 activates the wireless power receiver 1620 and receives Transmitting a digital ping to identify the device as a wireless power receiver 1620 In response to the digital ping, the wireless power receiver 1620 A signal strength packet can be transmitted (S1604).

[0273] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 1620 receives the identification information The identification packet for informing the information and the configuration packet for informing the configuration information are transmitted. (S1605 to S1606). 0 if the negotiation field value in the configuration packet indicates that the negotiation phase is to be performed You can move to the negotiation stage.

[0274] During the negotiation phase, the wireless power receiver 1620 sends an FOD status packet to detect the FOD. The FOD status packet may include a reference Q value. do.

[0275] The wireless power transmitter 1610 converts the received reference Q value into a predetermined Q value (e.g., less than 50). If the reference Q value is less than the preset Q value, it can be checked whether the reference Q value is less than the preset Q value (S1608). If so, the first foreign substance detection step is performed. If the reference Q value is equal to or greater than the preset Q value, If there is a second foreign substance, a step of detecting the second foreign substance is performed. That is, if the reference Q value is less than the set Q value, The lower the Q value, the greater the error in detecting foreign matter using the Q value. If the Q value is equal to or greater than the standard Q value, the error in detecting foreign matter using the Q value will be small. Depending on the Q value, each stage of the wireless power transmission method after detecting foreign matter is different. This can improve the accuracy of foreign substance detection and reduce unnecessary power consumption. According to the size of the foreign object, after detecting the foreign object, the wireless power transmission method is This will be explained with reference to the following.

[0276] If the reference Q value is less than the set Q value, the wireless power transmitter 1610 detects a first foreign substance. The first foreign substance detection can be performed (S1609). The first foreign substance detection is performed using the information in the state packet. Please refer to the description of the wireless charging method in Figs. 15a and 15a.

[0277] If the wireless power transmitter 1610 determines that a foreign substance is present after the first foreign substance detection, , and transmits a NAK to the wireless power receiver 1620 in response to the FOD status packet. On the other hand, after the first foreign substance detection, the wireless power transmitter 1610 If it determines that no foreign matter is present, it sends an ACK wirelessly in response to the FOD status packet. The power can be transmitted to a receiver 1620 .

[0278] When the wireless power transmitter 1610 transmits a NAK, it determines whether to perform wireless charging. The determination of whether to perform wireless charging is based on the measured Q value, the received The information in the FOD status packet can be used to determine whether to perform wireless charging. Please refer to the description of the wireless charging method in Figures 16a and 15b. If the wireless power transmitter 1610 transmits a NAK after the above, it determines whether to perform wireless charging. Wireless charging can be stopped without any steps.

[0279] As another example, if the reference Q value is less than a preset Q value of the wireless power transmitter, If the reference Q value is set to a value other than the predetermined value, the wireless charging can be stopped. If the Q value is equal to or greater than the set Q value, the first foreign substance detection can be performed.

[0280] The wireless power receiver 1620 receives a power transmission capability packet for a power transmission contract. The device may transmit a general request packet to request a connection (S1612).

[0281] If the wireless power transmitter 1620 determines to perform wireless charging after transmitting NAK, In response to the request packet, the power transmitter can transmit a power packet (S1613). In this case, the guaranteed power of the power transmission function power packet is the second guaranteed power value. On the other hand, if the wireless power transmitter 1620 transmits an ACK in S1610, the power transmission The guaranteed power of the functional power packet may be a first guaranteed power value. The first guaranteed power value may be greater than the second guaranteed power value. In particular, the second guaranteed power value may be greater than the It may be the minimum guaranteed power strength of the line power transmitter 1610. As another example, the first guaranteed power The second guaranteed power value may be 5 W or more and 15 W or less. .

[0282] The wireless power receiver 1620 transmits the power based on the second guaranteed power value of the power transmission packet. A special request packet can be transmitted to propose a guaranteed power value for the power transmission contract ( S1614). It should be noted that the second guaranteed power and power transmission of the power packet The contracted guaranteed power is distinguished. For example, the wireless power receiver 1620 The guaranteed power value of the power transmission contract is the same as or smaller than the second guaranteed power value of the transmission function power packet. For convenience of explanation, the wireless power receiver 1620 is The guaranteed power value in the transmission contract is requested to be the same as the second guaranteed power value in the power transmission function power packet. The line power transmitter 1610 sends a special request packet to request a guaranteed power value for the power transmission contract. In response to the received packet, an ACK packet can be transmitted (S1615). The power transmitter 1610 accepts the guaranteed power value of the power transmission contract proposed by the wireless power receiver. In other words, the power transmission contract can be completed at the second guaranteed power value. , the wireless power receiver 1620 performs a negotiation to end the negotiation phase once the power transfer agreement is completed. The wireless power transmitter 1610 can transmit a special request packet (S1616). Transmitting an ACK packet in response to a special request packet to terminate the negotiation phase That is, the wireless power transmitter 1610 can receive the reception for the end of the negotiation phase (S1617). An ACK packet can be transmitted as an acknowledgment.

[0283] After the wireless power transmitter 1610 has entered the power transmission stage, the wireless power transmitter 1610 is In particular, the wireless power transmitter 1610 can measure the internal temperature of the If a NAK is sent in response to a FOD status packet during the negotiation phase, the It is possible to transition to the power transfer phase rather than the forward phase.

[0284] The wireless power transmitter 1610 can determine whether to increase the transmission power strength. The decision to increase the transmission power intensity is based on the measured internal temperature, the stored preset temperature, and the The transmission power intensity increase decision can be made using the time period and the preset temperature. Please refer to the description of the wireless charging method in section b. If a decision is made to increase the power consumption, a renegotiation step can be performed. The receiver 1620 can transmit the received power packet to the wireless power transmitter 1610 ( In this case, the received power packet is a 24-bit received power packet. When the wireless power transmitter 1610 determines to increase the transmission power strength, it In response to the ACK packet, the NAK packet can be transmitted (S1621). The wireless power transmitter 1610 receives the renegotiation packet and accepts the transition to the renegotiation phase. The CK packet can be transmitted (S1622 to S1623). 0 can transmit a general request packet requesting a power transmission function power packet (S 1624). The wireless power transmitter 1610 may request a power transmission capability in response to the general request packet. In this case, the power transmission function can transmit the power packet (S1625). The interference power may be a third guaranteed power value. As another example, the third guaranteed power value may be greater than or equal to 5 W and less than or equal to 15 W. The wireless power receiver 1620 may transmit the power based on the third guaranteed power value of the power transmission packet. In this case, a special request packet can be transmitted to propose a guaranteed power value for the power transmission contract. It is important to note that the power transmission function is not guaranteed power and power transmission The guaranteed power of the transmission contract is different. For example, the wireless power receiver 1620 Guarantee the power transmission contract with a value equal to or smaller than the third guaranteed power value of the transmitter power packet For convenience of explanation, the wireless power receiver 1620 may propose a power value. The guaranteed power value in the transmission contract is proposed to be the same as the third guaranteed power value in the power transmission function packet. The wireless power transmitter 1610 sends a special request packet to propose a guaranteed power value for the power transmission contract. In response to the packet, an ACK packet can be transmitted (S1627). The line power transmitter 1610 accepts the guaranteed power value of the power transmission contract proposed by the wireless power receiver. In other words, the power transmission contract can be completed at the third guaranteed power value. After that, the wireless power receiver 1620 executes the renegotiation process to end the renegotiation phase when the power transfer contract is completed. The wireless power transmitter 1610 can transmit a special request packet for the purpose of ACK packet in response to a special request packet to terminate the renegotiation phase. That is, the wireless power transmitter 1610 can transmit the The wireless power transmitter 1610 and the wireless The power receiver 1620 transitions to the power transmission stage and performs wireless charging at the third guaranteed power. can be done.

[0285] Therefore, the wireless charging system according to the embodiment includes a wireless charging method and an apparatus therefor, and In addition, the wireless charging system according to the embodiment can provide a system for properly charging foreign substances. In addition, the wireless charging system according to the embodiment can accurately determine whether a foreign substance is present or not. As a result, heat generation, reduced charging efficiency, and wasted power consumption can be prevented.

[0286] 17a and 17b are diagrams illustrating a wireless power transmitter according to another embodiment of the present invention; 1 is a diagram illustrating a wireless charging method.

[0287] Referring to FIG. 17a and FIG. 17b, the wireless charging method in the wireless power transmitter is The method may include detecting an object in a region (S1701). The transmitter sends analog pings to sense objects based on changes in current in the transmit coil. This can be done.

[0288] The wireless charging method in the wireless power transmitter includes a step of measuring a Q value (S1 702). In one example, the wireless power transmitter may include a sensing unit in the selection step. The Q value can be measured using

[0289] The wireless charging method in the wireless power transmitter includes the step of receiving information including a reference Q value (S17 03). More specifically, the wireless power transmitter may include a FOD including a reference Q value. As an example, the wireless power transmitter may receive a status packet during the negotiation phase. The FOD status packet can be received using the unit. The Q value may be a Q value measured for a specific coil unit.

[0290] In the wireless charging method for the wireless power transmitter, the reference Q value is set to a predetermined Q value (for example, 50 The reference Q value may be set in advance. If the Q value is less than the predetermined Q value, the step of detecting the first foreign substance is performed. If the Q value is equal to or greater than the predetermined Q value, a second foreign substance detection step is performed. The lower the Q value (e.g., below 50), the greater the error in detecting foreign substances using the Q value. On the other hand, if the reference Q value is equal to or greater than the preset Q value, foreign matter detection using the Q value is possible. Therefore, the error of the wireless power transmission after detecting a foreign object is reduced depending on the magnitude of the reference Q value. By making each stage of the reception method different, the accuracy of foreign substance detection is improved and unnecessary power consumption is reduced. The force can be reduced.

[0291] In the wireless charging method of the wireless power transmitter, if the reference Q value is less than the preset Q value, , detecting a first foreign substance using the measured Q value and the reference Q value (S1705 to S1706). 1706).

[0292] As another example, if the reference Q value is less than a preset Q value of the wireless power transmitter, If the reference Q value is set to a predetermined value, the wireless charging can be stopped. If the value is equal to or greater than the Q value, the first foreign substance detection can be performed.

[0293] As another example, the wireless power transmitter may transmit a response signal to the foreign substance detection status packet. Positive acknowledge(ACK), Negative acknowledge(NAK), Not defined(ND), Cau The ACK signal can be modulated and transmitted to the wireless power receiver. It is a response signal to continue the wireless charging procedure when there is no quality. It may be a response signal that is determined to be present and causes the wireless charging procedure to be stopped. The signal can be used when it is difficult to determine whether a foreign substance is present. If it is difficult to determine whether the wireless power receiver is It may be less than 50. If the change in Q value is small due to friendly metal ( (The phenomenon in which Q-value damping due to power loss is blocked) and the comparison of the reference Q-value and the measured Q-value. In this case, it may be difficult to determine whether or not a foreign substance is present. This allows foreign matter detection based on power loss while charging at the minimum guaranteed power.

[0294] As another example, the Caution signal and NAK signal are based on the critical level of two types of reference Q values. The reference Q value received from the wireless power receiver is preset. If the value is between the first Q-value critical value and the preset second Q-value critical value (smaller than the first critical value), , a first foreign substance detection is performed, and if it is determined that a foreign substance is present as a result of the first foreign substance detection, If the received reference Q value is greater than the second Q value critical value, a Caution signal may be transmitted. If it is small, a NAK signal can be sent.

[0295] For example, as shown in FIG. 15a, the foreign substance detection step may include a step of determining a critical Q value (S15 11). More specifically, the wireless power transmitter uses the received reference Q value to The critical Q value can be calculated using the above formula. In any case, a value smaller than 10% can be determined as the critical Q value. 10% is the reference Q value. If there is a foreign substance, the measured Q value is smaller than the reference Q value by at least the allowable error. The foreign substance can be detected by utilizing the fact that the foreign substance is small. The step of determining whether the Q value is equal to or greater than the critical Q value (S1512) may be included. If the measured Q value of the wireless power transmitter is equal to or greater than the critical Q value, no foreign matter is detected. In addition, the wireless power transmitter can determine that the measured Q value is equal to or greater than the critical value (S1513). If it is less than the Q value, it can be determined that a foreign substance has been detected (S1514).

[0296] In the wireless charging method for the wireless power transmitter, a foreign substance is detected in the first foreign substance detection step. If it is determined that there is no such signal, an ACK can be transmitted to the wireless power receiver (S1707). , the wireless power transmitter wirelessly transmits an ACK packet in response to receiving the FOD status packet. Power can be transmitted to a receiver.

[0297] In the wireless charging method in the wireless power transmitter, if an ACK is sent, the first guaranteed power value is included. The method may include transmitting the information to a wireless power transmitter (S1708). The power transmitter and the wireless power receiver enter into a power transmission contract based on the first guaranteed power value. As an example, the first guaranteed power value may be 5W or more and 15W or less.

[0298] In the wireless charging method for the wireless power transmitter, when information including a first guaranteed power value is transmitted, The method may include a step of transitioning to a correction step and performing correction (S1709). In the correct execution, the wireless power transmitter measures the received power value of the wireless power receiver in the received power packet. The transmission power value can be used to predict power loss. The transmitter can use the predicted power loss value to increase the strength of the transmission power.

[0299] The wireless charging method in the wireless power transmitter performs correction and then transitions to the power transmission stage to achieve the first guarantee. The step of wirelessly charging the battery with power (S1710) may include the step of: Wireless charging is guaranteed by the power transmission contract concluded based on the first guaranteed power value. This may mean performing wireless charging according to a power value.

[0300] The wireless charging method for the wireless power transmitter is determined to be free of foreign matter by S1706. If the wireless power supply is disconnected, a NAK can be transmitted to the wireless power receiver (S1711). The power transmitter receives a NAK packet in response to the FOD status packet. can be transmitted to the machine.

[0301] The wireless charging method in the wireless power transmitter is that if NAK is sent in S1711, wireless charging For example, the method may include steps S1712 to S1713 for determining whether to perform the above-mentioned operation. As shown in FIG. 15b, the decision on whether to perform wireless charging is made in the step of determining the allowable Q value (S1 521). More specifically, the wireless power transmitter may include a As an example, as shown in Figure 7, The machine defines the allowable Q value (Qp) as the value that is reduced by 0% or more and 20% or less from the critical Q value (Qth). More specifically, the wireless power transmitter can be determined by the following formula: The reduced value can be determined as the allowable Q value. The decision on whether to perform wireless charging is made as follows: The method may include a step (S1522) of determining whether the measured Q value is equal to or greater than the determined allowable Q value. If the measured Q value is equal to or greater than the allowable Q value, the wireless power transmitter performs wireless charging. In addition, the wireless power transmitter determines whether the measured Q value is within the allowable Q value (S1523). If the value is less than the threshold, it can be determined that wireless charging is not to be performed (S1524). 8, when the frequency of the transmission power is the first frequency, the wireless power transmitter measures the Q value The first Q value (Q1), the second Q value (Q2), and the third Q value (Q3) may be used. If it is measured that there is no foreign object between the wireless power transmitter and the wireless power receiver, Since the value is very high, it can be determined that no foreign matter is present. When the third Q value (Q3) is measured, it is much lower than the critical Q value (Qth), so wireless power transmission is There is a very high probability that foreign matter exists between the transmitter and the wireless power receiver. If the second Q value (Q2) is measured, the second Q value (Q2) is considered to be clinically Since the Q factor (Qth) is between the boundary Q factor (Qth) and the allowable Q factor (Qp), To prevent this, the wireless power transmitter must If the measured Q value is equal to or greater than the allowable Q value, wireless charging can be performed. The power transmitter re-determines whether to stop wireless charging based on the internal temperature in S1718. Therefore, if the Q value of the wireless power transmitter is equal to or greater than the allowable Q value, wireless charging can be performed. This allows a further embodiment to accurately determine whether a foreign substance is present. Furthermore, in still another embodiment, the foreign substance can be accurately determined and the heat generation phenomenon, charging phenomenon, This can prevent the phenomenon of reduced efficiency and waste of power consumption. This solves the problem of wireless charging not working due to the previous misidentification of the presence of foreign matter. .

[0302] The wireless charging method in the wireless power transmitter determines that the wireless power transmitter does not perform wireless charging. If so, the step of stopping wireless charging (S1714) may be included. In this case, the wireless power transmitter will move to the selection phase after a predetermined time has elapsed in the negotiation phase. can be done.

[0303] The wireless charging method in the wireless power transmitter includes: The method may include transmitting information including the value to the wireless power receiver (S1715). In this case, the wireless power transmitter and the wireless power receiver establish a power transmission agreement based on the second guaranteed power value. As an example, the first guaranteed power value may be greater than the second guaranteed power value. The second guaranteed power value may be the minimum guaranteed power intensity of the wireless power transmitter. The second guaranteed power value may be 5W or less.

[0304] In the wireless charging method in the wireless power transmitter, when information including the second guaranteed power value is transmitted, If so, the step of transitioning to the power transmission step without the correction step and wirelessly charging with the second guaranteed power (S17 In this case, wireless charging at the second guaranteed power may include the second guaranteed power. Wireless charging is performed according to the guaranteed power value in the power transmission contract concluded based on the power value. It can mean:

[0305] The wireless charging method for the wireless power transmitter involves measuring the internal temperature of the wireless power transmitter, such as the charging area. A measuring step (S1717) may be included.

[0306] The wireless charging method in the wireless power transmitter is to keep the internal temperature at a predetermined value for a predetermined period of time. The method may include determining whether the temperature is lower than a predetermined temperature (S1718). The selected time period and the preset temperature may be stored values.

[0307] The wireless charging method in the wireless power transmitter is to keep the internal temperature at a predetermined value for a predetermined period of time. If the temperature reaches or exceeds the predetermined temperature, the step of stopping wireless charging (S1719) may be included. Specifically, in this case, the wireless power transmitter selects the power source after a predetermined time has elapsed during the power transmission stage. That is, the wireless power transmitter can move to the internal selection stage for a preset period. If the temperature exceeds a preset level, it will determine that a foreign object is present and stop wireless charging. It can be done.

[0308] The wireless charging method in the wireless power transmitter is to keep the internal temperature at a predetermined value for a predetermined period of time. If the temperature is lower than the predetermined temperature, a renegotiation step (S1720) may be performed. As a result, the wireless power transmitter sends a NAK packet in response to a received power packet. The wireless power transmitter then sends a renegotiation packet to the wireless power receiver. In other words, the wireless power transmitter can transmit the preset If the internal temperature remains below a preset temperature for the specified period, it is determined that no foreign matter is present. The transmitted power intensity can be increased.

[0309] When the wireless charging method in the wireless power transmitter enters the renegotiation stage, the third guaranteed power value is In this case, the method may include a step of transmitting information including: The wireless power transmitter and the wireless power receiver enter into a power transmission contract based on the third guaranteed power value. As an example, the third guaranteed power value may be greater than the second guaranteed power value. The third guaranteed power value may be 5 W or more and 15 W or less. Considering that a NAK was sent by the They may be the same.

[0310] The wireless charging method in the wireless power transmitter is to move to the power transmission stage and wirelessly charge with the third guaranteed power. In this case, the wireless charging may be performed at the third guaranteed power. The purpose of this is to comply with the guaranteed power value in the power transmission contract concluded based on the third guaranteed power value. This means that the wireless power transmitter can exchange In the interference stage, it determines that a foreign substance has been detected and reduces the transmission power strength to protect the system. At the power transmission stage, it is determined that no foreign matter is detected and the transmission power strength is increased to The line charging efficiency can be increased.

[0311] The wireless charging method for wireless power transmitters is S1704, and the reference Q value is not less than 50. , and may include a step of detecting a second foreign substance (S1723 to S1724). As shown in FIG. 15a, the foreign substance detection step includes a step of determining a critical Q value (S1511). More specifically, the wireless power transmitter can calculate the critical Q value by using the received reference Q value. The wireless power transmitter must have a reference Q factor of at least 10%. The smallest value can be determined as the critical Q value. 10% is the tolerance for the reference Q value, When foreign matter is present, the measured Q value will be smaller than the reference Q value by at least the allowable error. In addition, the foreign substance detection step is performed by determining whether the measured Q value is a critical value. The wireless power transmitter may include determining whether the Q value is equal to or greater than the Q value (S1512). If the measured Q value is equal to or greater than the critical Q value, it can be determined that no foreign matter has been detected. In addition, if the measured Q value is less than the critical Q value, the wireless power transmitter It can be determined that a foreign substance has been detected (S1514).

[0312] If the wireless power transmitter determines that no foreign substance is detected in the second foreign substance detection step, the wireless power transmitter You can move to the 707.

[0313] The wireless charging method for the wireless power transmitter is determined to be free of foreign matter by S1724. If the wireless power supply is disconnected, a NAK can be transmitted to the wireless power receiver (S1725). The power transmitter receives a NAK packet in response to the FOD status packet. can be transmitted to the machine.

[0314] The wireless charging method in the wireless power transmitter is that when NAK is sent by S1725, wireless charging That is, after the second foreign substance is detected, the step of terminating the wireless power transmission (S1726) may be included. If the receiver sends NAK, wireless charging will be stopped without determining whether to continue wireless charging. More specifically, in this case, the wireless power transmitter can be stopped by a predetermined After a certain time has passed, you can move on to the selection stage.

[0315] FIG. 18 is a diagram illustrating a wireless charging method in a wireless power transmitter according to yet another embodiment. This is a drawing for reference.

[0316] Referring to FIG. 18, the wireless charging method in the wireless power transmitter detects an object in the charging area. More specifically, the wireless power transmitter may include a step of transmitting an analog signal (S1801). The object can be sensed based on the change in current in the transmitting coil by transmitting a signal.

[0317] The wireless charging method in the wireless power transmitter includes a step of measuring a Q value (S1 802). In one example, the wireless power transmitter may include a sensing unit in the selection step. The Q value can be measured using

[0318] The wireless charging method in the wireless power transmitter includes the step of receiving information including a reference Q value (S18 03). More specifically, the wireless power transmitter may include a FOD including a reference Q value. A status packet can be received.

[0319] The wireless charging method in the wireless power transmitter uses the measured Q value and the reference Q value to The method may include steps of detecting a substance (S1804 to S1805). As in a, the step of detecting foreign matter may include a step of determining a critical Q value (S1511). More specifically, the wireless power transmitter calculates the critical Q value using the received reference Q value. The wireless power transmitter should have a reference Q value of at least 10% lower. can be determined as the critical Q value. 10% is the tolerance for the reference Q value, and If there is a problem, the measured Q value will be smaller than the reference Q value by at least the allowable error. In addition, the foreign substance detection step is performed when the measured Q value is equal to or greater than the critical Q value. The wireless power transmitter may include a step of determining whether the power supply is above the power supply voltage (S1512). If the detected Q value is equal to or greater than the critical Q value, it can be determined that no foreign matter has been detected. (S1513). In addition, if the measured Q value is less than the critical Q value, the wireless power transmitter detects the presence of a foreign object. It can be determined that quality has been detected (S1514).

[0320] The wireless charging method in the wireless power transmitter determines that no foreign substance is detected. The method may include transmitting information including a guaranteed power value to a wireless power transmitter (S1807). In this case, the wireless power transmitter controls the power based on the wireless power receiver and the first guaranteed power value. A transmission contract is concluded. For example, the first guaranteed power value may be greater than 5W. Then, the wireless power transmitter can transition to the power transmission stage and perform wireless charging at the first guaranteed power. In this case, wireless charging at the first guaranteed power is concluded based on the first guaranteed power value. This means that wireless charging is performed according to the guaranteed power value set by the power transmission contract. do.

[0321] The wireless charging method for the wireless power transmitter determines that a foreign substance is detected in step S1805. and transmitting information including the second guaranteed power value to the wireless power receiver (S1807). In this case, the wireless power transmitter can perform the following operation based on the wireless power receiver and the second guaranteed power value: A power transmission contract is concluded. For example, the first guaranteed power value is greater than the second guaranteed power value. In particular, the second guaranteed power value may be the minimum guaranteed power intensity of the wireless power transmitter. As another example, the second guaranteed power value may be 5 W or less. can transition to the power transmission stage without the correction stage and perform wireless charging at the second guaranteed power. In this case, wireless charging at the second guaranteed power is performed according to the second guaranteed power value. This may mean that wireless charging is performed according to the guaranteed power value according to the power transmission contract. In addition, if the receiver determines that there is no foreign matter after a certain period of time has passed, it will renegotiate and The interference power can also be increased.

[0322] FIG. 19 illustrates a wireless charging method in a wireless charging system according to yet another embodiment. This is a drawing for

[0323] Referring to FIG. 19, a wireless power transmitter 1910 selects a wireless power receiver 1920. An analog ping can be transmitted to (S1901).

[0324] The wireless power transmitter 1910 can measure the Q factor before the ping stage (S190 2) As an example, the wireless power transmitter 1910 can measure the Q factor during the selection stage. .

[0325] The wireless power transmitter 1910 transitions from the selection phase to the ping phase when an object is detected. The wireless power transmitter 1910 activates the wireless power receiver 1920 and receives Transmitting a digital ping to identify the device as a wireless power receiver 1920 In response to the digital ping, the wireless power receiver 1920 A signal strength packet can be transmitted (S1904).

[0326] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 1920 receives the identification information The identification packet for informing the information and the configuration packet for informing the configuration information are transmitted. (S1905 to S1906). 0 if the negotiation field value in the configuration packet indicates that the negotiation phase is to be performed You can move to the negotiation stage.

[0327] During the negotiation phase, the wireless power receiver 1920 sends an FOD status packet to detect the FOD. The FOD status packet may include a reference Q value. do.

[0328] The wireless power transmitter 1910 may perform foreign substance detection (S1908). detects foreign substances using the measured Q value and the information of the received FOD status packet. For foreign object detection, refer to the description of the wireless charging method in FIG. 20.

[0329] If the wireless power transmitter 1910 determines that a foreign substance is present after detecting the foreign substance, A NAK may be transmitted to the wireless power receiver 1920 in response to the OD status packet. On the other hand, the wireless power transmitter 1910 detects the foreign matter and then determines whether the foreign matter is present (S1909). If it determines that it does not exist, it sends an ACK in response to the FOD status packet. The wireless power transmitter 1910 can transmit the power to the device 1920. If the wireless power transmitter 1910 determines that the wireless charging is stopped, the wireless power transmitter 1910 can stop the wireless charging. After a predetermined time has elapsed in the negotiation phase, the selection phase can begin.

[0330] FIG. 20 is a diagram illustrating a wireless charging method in the wireless power transmitter according to the embodiment of FIG. 21 is a diagram for explaining a method for detecting foreign matter according to the Q value in FIG. 20. This is a drawing of the

[0331] Referring to FIG. 20, a wireless charging method in a wireless power transmitter according to an embodiment includes: More specifically, the wireless power transmission method may include a step of detecting an object in a wireless power transmission area (S2001). The receiver sends analog pings and senses objects based on the current changes in the transmitting coil. can be done.

[0332] The wireless charging method in the wireless power transmitter includes a step of measuring a Q value (S2 002). In one example, the wireless power transmitter may include a sensing unit in the selection step. The Q value can be measured using

[0333] The wireless charging method in the wireless power transmitter includes the step of receiving information including a reference Q value (S20 03). More specifically, the wireless power transmitter may include a FOD including a reference Q value. A status packet can be received.

[0334] The wireless charging method in the wireless power transmitter includes determining a critical Q value (S2004). More specifically, the wireless power transmitter can calculate the critical Q value by using the received reference Q value. As an example, as shown in FIG. 21, the wireless power transmitter can calculate the reference Q value. Determine the critical Q value (Qth) to be at least 10% less than (Qr). 10% is the tolerance of the standard Q value, and if there is a foreign substance, it is possible to Foreign substances can be detected by taking advantage of the fact that the measured Q value is smaller than the reference Q value. .

[0335] The wireless charging method for wireless power transmitters determines whether the measured Q value is below the critical Q value. The wireless power transmitter may include determining whether the measured Q value is a critical value. If the Q value is below the threshold, it can be determined that a foreign substance is present. If the measured Q value is not less than the critical Q value, it can be determined that no foreign matter is present. As an example, when the frequency of the transmission power is the first frequency (f1) as shown in FIG. In the wireless power transmitter, the measured Q value may be a first Q value (Q1) and a second Q value (Q2). Since the Q factor (Q1) is greater than the critical Q factor (Qth), It can be determined that no foreign matter exists in the Because it is so small, it is possible to determine that a foreign object exists between the wireless power transmitter and the wireless power receiver. can.

[0336] The wireless power transmitter may stop wireless charging if the measured Q value is below the critical Q value. In other words, if the wireless power transmitter determines that a foreign substance is present, it can On the other hand, the wireless power transmitter is designed to operate when the measured Q value is below the critical Q value. If not, wireless charging can be performed (S2007). That is, the wireless power transmitter If it is determined that no foreign matter is present, wireless charging can be performed.

[0337] Therefore, in one embodiment, it is possible to accurately determine whether a foreign substance is present. Accurately assess the quality to prevent heat generation, reduced charging efficiency, and wasted power consumption can be done.

[0338] FIG. 22 illustrates a wireless charging method in a wireless charging system according to yet another embodiment. This is a drawing for

[0339] Referring to FIG. 22, the wireless power transmitter 2210 selects the wireless power receiver 2220. An analog ping can be transmitted to (S2201).

[0340] The wireless power transmitter 2210 can measure the equivalent series resistance before the ping stage. (S2202). As an example, the wireless power transmitter 2210 measures the equivalent series resistance value in the selection step. It can be determined (S2202).

[0341] The wireless power transmitter 2210 transitions from the selection phase to the ping phase when an object is detected. The wireless power transmitter 2210 activates the wireless power receiver 2220 and receives Transmitting a digital ping to identify the device as a wireless power receiver 2220 In response to the digital ping, the wireless power receiver 2220 A signal strength packet can be transmitted (S2204).

[0342] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 2220 receives the identification information The identification packet for informing the information and the configuration packet for informing the configuration information are transmitted. (S2205 to S2206). 0 if the negotiation field value in the configuration packet indicates that the negotiation phase is to be performed You can move to the negotiation stage.

[0343] During the negotiation phase, the wireless power receiver 2220 sends an FOD status packet to detect the FOD. The FOD status packet can be transmitted (S2207). It may include a frequency value.

[0344] The wireless power transmitter 2210 may perform foreign substance detection (S2208). detects foreign substances using the measured equivalent series resistance and the received FOD status packet information. For foreign object detection, refer to the description of the wireless charging method in FIG.

[0345] If the wireless power transmitter 2210 determines that a foreign substance is present after detecting the foreign substance, A NAK may be transmitted to the wireless power receiver 2220 in response to the OD status packet. On the other hand, the wireless power transmitter 2210 detects the foreign matter and then If it determines that it does not exist, it sends an ACK in response to the FOD status packet. The wireless power transmitter 2210 can transmit power to the device 2220. If the wireless power transmitter 2210 determines that the wireless charging is stopped, the wireless power transmitter 2210 can stop the wireless charging. After a predetermined time has elapsed in the negotiation phase, the selection phase can begin.

[0346] FIG. 23 illustrates a wireless charging method in a wireless power transmitter according to another embodiment of FIG. FIG. 24 is a diagram for explaining a method for detecting foreign matter according to an equivalent series resistance value. This is a drawing.

[0347] Referring to FIG. 23, a wireless charging method in a wireless power transmitter according to an embodiment includes: More specifically, the wireless power transmission may include a step of detecting an object in a wireless power transmission area (S2301). The receiver sends analog pings and senses objects based on the current changes in the transmitting coil. can be done.

[0348] The wireless charging method for the wireless power transmitter measures the equivalent series resistance before the ping step In one example, the wireless power transmitter may include a sensor in the selection step. The equivalent series resistance can be measured using the sizing portion.

[0349] The wireless charging method in the wireless power transmitter includes information including a reference Q value and a reference peak frequency value. More specifically, the wireless power transmitter may include receiving information (S2303). , a FOD status packet including a reference Q value and a reference peak frequency value can be received. For example, the wireless power transmitter receives the FOD status packet using the communication unit during the negotiation stage. The reference Q value and the reference peak frequency value can be transmitted. The value and the peak frequency value may also be used.

[0350] The wireless charging method for the wireless power transmitter includes a step of determining a first critical equivalent series resistance value (S 2304), where the first critical equivalent series resistance value is a reference equivalent series resistance The reference equivalent series resistance value is determined based on the mathematical formulas 2 and 3. Since this has already been described, a detailed description thereof will be omitted.

[0351] Referring to FIG. 24, as an example, the wireless power transmitter has a reference equivalent series resistance (ESRr) The value increased by a predetermined percentage is determined to be the first critical equivalent series resistance (ESRth1). In this case, the predetermined ratio may be 10%. The value obtained by decreasing the reference equivalent series resistance (ESRr) by a specified percentage is called the second critical equivalent series resistance. The value (ESRth2) can be determined. At this time, the predetermined ratio is 10%. 10% is the tolerance of the reference equivalent series resistance value, and if there is foreign matter, The measured equivalent series resistance is greater than the reference equivalent series resistance by more than the allowable error. As another example, the wireless power transmitter can detect foreign matter by using a reference equivalent series resistance (ESR). The maximum value of (ESRr) is determined to be the first critical equivalent series resistance value (ESRth1), and the reference equivalent Determine the minimum value of series resistance (ESRr) to be the second critical equivalent series resistance value (ESRth2) As another example, the first critical equivalent series resistance (ESRth1) can be set to 50 mΩ. The second critical equivalent series resistance (ESRth2) is 500 mΩ or more. As another example, the first critical equivalent series resistance (ESRth1) may be It may be smaller than the series resistance value (ESRth2).

[0352] The wireless charging method in the wireless power transmitter is to measure the equivalent series resistance (ESR) of the first critical equivalent series resistance (ESR). The method may further include determining whether the resistance is greater than or equal to the string resistance value (S2305). If the measured equivalent series resistance is equal to or greater than the first equivalent series resistance, the device determines that a foreign substance is present. On the other hand, the wireless power transmitter can be judged as having a measured equivalent series resistance of 1st critical value. If the value is not greater than the equivalent series resistance of the field, it can be determined that no foreign matter is present. As shown in FIG. 24, the wireless power transmitter measures the equivalent series resistance of the first equivalent series resistance. The first equivalent series resistance value (ESR1) may be a first equivalent series resistance value (ESR2). Since the ESR1 is smaller than the first critical equivalent series resistance (ESRth1), It can be determined that there is no foreign material between the wireless power receiver and the second equivalent series resistance Since (ESR2) is larger than the first critical equivalent series resistance (ESRth1), It can be determined that a foreign object exists between the wireless power receivers.

[0353] If the measured equivalent series resistance value of the wireless power transmitter is equal to or greater than the first critical equivalent series resistance value, If the foreign matter is detected, the wireless power transmitter can stop the wireless charging (S2306). If it detects the presence of a wireless power source, it can stop wireless charging. If the measured equivalent series resistance is not equal to or greater than the first critical equivalent series resistance, wireless charging is stopped. That is, the wireless power transmitter can determine that no foreign substance is present (S2307). This allows wireless charging.

[0354] Therefore, in another embodiment, the presence of foreign matter can be accurately determined. Accurately detects foreign substances to prevent heat generation, reduced charging efficiency, and wasteful power consumption It is possible.

[0355] FIG. 25 illustrates a wireless charging method in a wireless charging system according to yet another embodiment. This is a drawing for

[0356] Referring to FIG. 25, a wireless power transmitter 2510 selects a wireless power receiver 2520. An analog ping can be transmitted to the mobile station (S2501).

[0357] The wireless power transmitter 2510 can measure the equivalent series resistance before the ping stage. (S2502). As an example, the wireless power transmitter 2510 measures the equivalent series resistance value in the selection step. It can be determined (S2502).

[0358] The wireless power transmitter 2510 may also measure the peak frequency value before the ping stage. In one example, the wireless power transmitter 2510 may select a peak frequency in the selection step (S2503). As another example, the wireless power transmitter 2510 may measure a selected value (S2502). The peak frequency of the transmitting coil can be measured during the selection stage to determine the inductance value. .

[0359] The wireless power transmitter 2510 transitions from the selection phase to the ping phase when an object is detected. The wireless power transmitter 2510 activates the wireless power receiver 2520 and receives Transmitting a digital ping to identify the device as a wireless power receiver 2520 In response to the digital ping, the wireless power receiver 2520 A signal strength packet can be transmitted (S2505).

[0360] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 2520 receives the identification information The identification packet for informing the information and the configuration packet for informing the configuration information are transmitted. (S2506 to S2507). 0 if the negotiation field value in the configuration packet indicates that the negotiation phase is to be performed You can move to the negotiation stage.

[0361] During the negotiation phase, the wireless power receiver 2520 sends an FOD status packet to detect the FOD. The FOD status packet can be transmitted (S2508). It may include any one or more of the frequency values.

[0362] The wireless power transmitter 2510 may perform foreign substance detection (S2509). is the measured peak frequency value, the measured equivalent series resistance value, and the received FOD status packet Foreign matter detection can be performed using the information from the wireless charging method shown in Figure 26. See the corresponding description.

[0363] If the wireless power transmitter 2510 determines that no foreign substance is present after detecting the foreign substance, Transmitting an ACK to the wireless power receiver 2520 in response to the FOD status packet On the other hand, the wireless power transmitter 2510 detects the foreign matter and then If it determines that FOD exists, it sends a NAK in response to the FOD status packet. The signal can be transmitted to the device 2520.

[0364] The wireless power receiver 2520 receives a power transmission capability packet for a power transmission contract. The wireless power transmitter can transmit a general request packet to request a power source (S2511). 2520 can transmit a power transmitter request packet in response to a general request packet. In this case, the guaranteed power of the power transmission function power packet is The wireless power receiver 1120 may transmit the first power value of the power packet. A special request packet for proposing a guaranteed power value for a power transmission contract based on the guaranteed power value. The wireless power transmitter 2510 can transmit the power transmission contract (S2513). An ACK packet is transmitted in response to a special request packet for requesting a power value. That is, the wireless power transmitter 2510 can receive the power of the wireless power receiver proposed by the In other words, the power transmission contract is a contract in which the guaranteed power value of the first The power transmission contract can be completed at the guaranteed power value. Once S is complete, a special request packet can be transmitted to end the negotiation phase (S 2515). The wireless power transmitter 2510 sends a special request packet to end the negotiation phase. In response to the request, an ACK packet can be transmitted (S2516). The transmitter 2510 may transmit an ACK packet as an acknowledgment for the end of the negotiation phase. Cut.

[0365] In the correction stage, the wireless power receiver 2520 transfers the received power packet to the wireless power transmitter 2510. In this case, the received power packet can be transmitted to the 24-bit reception The wireless power transmitter 2510 may transmit the received power packet to the power supply 2510 for wireless charging. An ACK packet can be transmitted in response to the input packet (S2518).

[0366] Once the correction step is completed, the power transmission step can be performed at the first guaranteed power. The receiver 2520 includes one or more control elements for controlling the transmission power of the wireless power transmitter 2510. The wireless power receiver 2520 can periodically transmit a packet (S2519). The received power packet may be transmitted either immediately or arbitrarily (S2520).

[0367] FIG. 26 illustrates a wireless charging method in a wireless power transmitter according to yet another embodiment of FIG. 27 is a diagram for explaining the method of detecting foreign matter according to the frequency value in FIG. 1 is a diagram for explanation.

[0368] Referring to FIG. 26, the wireless charging method in the wireless power transmitter according to the embodiment is The method may include detecting an object in a wireless area (S2601). The force transmitter sends analog pings to sense objects based on changes in current in the transmitting coil. It is possible.

[0369] The wireless charging method in the wireless power transmitter is to calculate the equivalent series resistance and peak resistance before the peak stage. For example, the step of measuring a frequency value of the wireless power transmission may include the step of measuring a frequency value of the wireless power transmission. The device can measure the equivalent series resistance value using the sensing unit in the selection step. In the selection step, the wireless power transmitter measures the peak frequency value of the transmission power using the sensing unit. It can be determined.

[0370] The wireless charging method in the wireless power transmitter includes information including a reference Q value and a reference peak frequency value. More specifically, the wireless power transmitter may include receiving information (S2603). , a FOD status packet including a reference Q value and a reference peak frequency value can be received. For example, the wireless power transmitter receives the FOD status packet using the communication unit during the negotiation stage. The reference Q value and the reference peak frequency value can be transmitted. The value and the peak frequency value may also be used.

[0371] The wireless charging method in the wireless power transmitter is The step of determining wave values ​​(S2604) may include determining a second critical equivalent wave value. The method for determining the series resistance is the same as the method for determining the second critical equivalent series resistance in Figure 23. The wireless power transmitter may calculate the critical peak frequency using the received reference peak frequency value. As an example, as shown in FIG. 27, the wireless power transmitter The peak frequency value (fr) is at least 5 kHz greater than the critical peak frequency value (Ft h) 5 kHz is the tolerance for the reference peak frequency value. If there is foreign matter, the measured peak frequency value must be at least equal to the reference peak frequency value. This larger size can be used to detect foreign substances.

[0372] The wireless charging method in the wireless power transmitter is such that the measured peak frequency value is equal to or exceeds the critical peak frequency. The method may further include determining whether the value is equal to or greater than a predetermined value (S2605). A line-powered transmitter shall be deemed to be in an abnormal state if the measured peak frequency value is not greater than or equal to the critical peak frequency value. It can be determined that no substance is present. The wireless power transmitter is measured by S2605. If the peak frequency value is not the critical peak frequency value, wireless charging can be performed (S2 606) As an example, as shown in Figure 27, the wireless power transmitter has a measured peak frequency value of The first peak frequency value (f1) may be a critical peak frequency. Since the value is smaller than the value (Fth), it can be determined that no foreign matter is present. The wireless power transmitter ensures that the measured peak frequency value is not greater than the critical peak frequency value. It determines that no foreign substance is present and transmits information indicating that no foreign substance has been detected via wireless power. It can be transmitted to a receiver.

[0373] The wireless charging method in the wireless power transmitter is to measure the peak frequency value within the critical peak frequency range. If it is greater than the value, check whether the measured equivalent series resistance is less than the second critical equivalent series resistance. The wireless power transmitter may include a step of determining (S2607) the measured peak frequency. The wave number is equal to or greater than the critical peak frequency value, and the measured equivalent series resistance is equal to or greater than the second critical equivalent series resistance. If the resistance is equal to or less than the measured value, wireless charging can be performed (S2606). The peak frequency value measured is equal to or greater than the critical peak frequency value, and the equivalent series resistance measured is If the resistance is not equal to or less than the second critical equivalent series resistance, wireless charging can be stopped (S260 8) More specifically, the wireless power transmitter must ensure that the measured peak frequency is within the critical peak frequency range. If the measured equivalent series resistance is equal to or less than the second critical equivalent series resistance, The wireless power receiver determines that no foreign substance is present and sends information indicating that no foreign substance has been detected. The wireless power transmitter can transmit the measured peak frequency value to the critical peak. The measured equivalent series resistance is not less than the second critical equivalent series resistance. If a foreign substance is not detected, the device determines that a foreign substance is present and transmits information indicating that a foreign substance has been detected via wireless power. More specifically, the wireless power transmitter and the wireless power receiver can be charged. When the distance between the wireless power transmitter and the wireless power receiver increases, for example, the height of the wireless power transmitter increases. The peak frequency measured at the transmitter increases and the equivalent series resistance decreases. If there is any foreign material in the charging area of ​​the device and wireless power receiver, the peak frequency value will increase and the equivalent direct current The series resistance also increases. Therefore, the wireless power transmitter has a low measured equivalent series resistance. When the peak frequency value meets all the conditions, the wireless power transmitter and the wireless power receiver can be charged. The electrical distance has increased, and it can be determined that no foreign matter is present. The wireless power transmitter may mistakenly detect the presence of a foreign object due to an increase in the measured peak frequency. As an example, as shown in FIG. 27, the wireless power transmitter measures The peak frequency value may be a second peak frequency value (f2). 2) is greater than the critical peak frequency (Fth), so it is not suitable for situations where foreign matter is present or when the charging distance is short. At the same time, as shown in Figure 24, the wireless power transmitter The determined equivalent series resistance may be a third equivalent series resistance (ESR3). Since the resistance value (ESR3) is smaller than the second critical equivalent series resistance value (ESRth2), the foreign matter It can be determined that this is not a situation where quality exists, but a situation where the charging distance has increased.

[0374] Therefore, in yet another embodiment, foreign substances can be accurately determined. The embodiment accurately detects foreign substances and prevents heat generation, reduced charging efficiency, and wasted power consumption. In yet another embodiment, a wireless power transmitter and a wireless power receiver are connected to each other. By distinguishing between an increase in the charging distance and the presence of foreign matter, unnecessary This can solve the problem of wireless charging not working.

[0375] FIG. 28 illustrates a wireless charging method in a wireless charging system according to yet another embodiment. This is a drawing for

[0376] Referring to FIG. 28, a wireless power transmitter 2810 selects a wireless power receiver 2820. An analog ping can be transmitted to (S2801).

[0377] The wireless power transmitter 2810 determines the Q value, the equivalent series resistance, and the peak frequency before the ping stage. The wireless power transmitter 2810 can measure the value (S2802). In the selection step, the equivalent series resistance value can be measured (S2802). This may be the same as the description in FIG.

[0378] The wireless power transmitter 2810 transitions from the selection phase to the ping phase when an object is detected. The wireless power transmitter 2810 activates the wireless power receiver 2820 and receives Transmitting a digital ping to identify the device as a wireless power receiver 2820 In response to the digital ping, the wireless power receiver 2820 A signal strength packet can be transmitted (S2804).

[0379] Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 2820 receives the identification information The identification packet for informing the information and the configuration packet for informing the configuration information are transmitted. (S2805 to S2806). 0 if the negotiation field value in the configuration packet indicates that the negotiation phase is to be performed You can move to the negotiation stage.

[0380] During the negotiation phase, the wireless power receiver 2820 sends an FOD status packet to detect the FOD. The FOD status packet can be transmitted (S2808). It may include any one or more of the frequency values.

[0381] The wireless power transmitter 2810 may perform a first foreign substance detection (S2808). The detection is performed by measuring either the Q factor or the equivalent series resistance and the received FOD status parameter. The first foreign substance detection is performed by using the information from the foreign substance detection device shown in FIG. Please refer to the explanation of the foreign substance detection method in FIG. 23 and the wireless charging method in FIG. 29. .

[0382] The wireless power transmitter 2810 determines that no foreign substance is detected through the first foreign substance detection. Then, the second foreign substance detection can be performed (S2809). Foreign matter can be detected using the frequency value and information of the received FOD status packet. The second foreign substance detection is a method for detecting a foreign substance shown in FIG. 26 and a method for wireless charging shown in FIG. 29. See the instructions.

[0383] The wireless power transmitter 2810 determines that no foreign substance is present after performing the second foreign substance detection. and transmits an ACK to the wireless power receiver 2820 in response to the FOD status packet. On the other hand, the wireless power transmitter 2810 performs the second foreign substance detection. If it determines that foreign matter is present, it sends a NAK wirelessly in response to the FOD status packet. The power can be transmitted to a receiver 2820 .

[0384] The wireless power receiver 2820 receives a power transmission capability packet for a power transmission contract. The wireless power transmitter can transmit a general request packet to request a power source (S2811). 2820 can transmit a power transmitter request packet in response to a general request packet. In this case, the guaranteed power of the power transmission function power packet is The potential power value may be a guaranteed power value. The potential power value is regardless of power limitations due to peripheral requirements, etc. It may be the maximum transmission power value that the wireless power transmitter can transmit. The value is based on the power supply provided by the power supply unit of the wireless power transmitter. Even if the value is close to the potential power value that is not subject to power limitations due to the number of wireless power receivers, As another example, the first guaranteed power value may be set based on the number of wireless power transmitters or the number of wireless power receivers. The maximum power that a wireless power transmitter can transmit under certain conditions (environmental conditions) such as power limitations. Environmental conditions include the temperature of the transmitter, the available capacity of the transmitter's power source, and the presence of foreign matter. This can refer to the influence of the wireless power receiver 142. 0 is the guaranteed power of the power transmission contract based on the first guaranteed power value of the power transmission function power packet. A special request packet can be transmitted to propose a value (S2813). That is, the first guaranteed power of the power transmission function power packet and the guaranteed power of the power transmission contract are distinguished. For example, the wireless power receiver 2820 may transmit a first packet of power. You can request a guaranteed power value for the power transmission contract that is equal to or smaller than the interference power value. For convenience of explanation, it is assumed that the wireless power receiver 2820 receives power at the guaranteed power value of the power transmission contract. The wireless power transmitter 2810 requests the same value as the first guaranteed power value in the transmitter power packet. AC in response to a special request packet to request the guaranteed power value of a power transmission contract In other words, the wireless power transmitter 2810 can transmit K packets (S2814). This is the case when the line power receiver accepts the guaranteed power value of the power transmission contract proposed. The transmission contract can be completed at the first guaranteed power value. Once the power transfer agreement is completed, the The wireless power transmitter 2810 can execute a special command to complete the negotiation phase (S2815). An ACK packet can be transmitted as a response to another request packet (S2816). That is, the wireless power transmitter 2810 sends an ACK packet as an acknowledgment to the end of the negotiation phase. It can be transmitted.

[0385] In the correction stage, the wireless power receiver 2820 transmits the received power packet to the wireless power transmitter 2810. In this case, the received power packet can be transmitted to the 24-bit reception The wireless power transmitter 2810 may transmit the received power packet to the An ACK packet can be transmitted as a response to the input packet (S2818).

[0386] Once the correction step is completed, the power transmission step can be performed at the first guaranteed power. The receiver 2820 includes one or more control elements for controlling the transmission power of the wireless power transmitter 2810. The wireless power receiver 2820 can periodically transmit a packet (S2819). The received power packet may be transmitted either immediately or arbitrarily (S2820).

[0387] FIG. 29 illustrates a wireless charging method in a wireless power transmitter according to another embodiment of FIG. This is a drawing for

[0388] Referring to FIG. 29, the wireless charging method in the wireless power transmitter according to the embodiment is The method may include the step of detecting an object in a wireless area (S2901). The force transmitter sends analog pings to sense objects based on changes in current in the transmitting coil. It is possible.

[0389] The wireless charging method in the wireless power transmitter is to determine the Q value, equivalent series resistance and The method may include a step of measuring a peak frequency value (S2902). The power transmitter can measure the Q value using the sensing unit in the selection stage. The line power transmitter can measure the equivalent series resistance value using the sensing unit during the selection stage. In addition, the wireless power transmitter uses a sensing unit to determine the peak frequency of the transmission power during the selection stage. The wave number can be measured.

[0390] The wireless charging method in the wireless power transmitter includes information including a reference Q value and a reference peak frequency value. More specifically, the wireless power transmitter may include receiving information (S2903). , a FOD status packet including a reference Q value and a reference peak frequency value can be received. For example, the wireless power transmitter receives the FOD status packet using the communication unit during the negotiation stage. The reference Q value and the reference peak frequency value can be transmitted. The value and the peak frequency value may also be used.

[0391] The wireless charging method in the wireless power transmitter is based on the critical Q value, the first critical equivalent series resistance value, the second critical and determining a field equivalent series resistance value and a critical peak frequency value (S2904). The method for determining the critical Q value may be the same as the method for determining the critical Q value in FIG. The method for determining the first critical equivalent series resistance value and the second critical equivalent series resistance value is shown in FIG. The method for determining the first and second critical equivalent series resistance values ​​may be the same as that of 23. The method for determining the critical peak frequency value is the same as the method for determining the critical peak frequency value in FIG. It may be one.

[0392] The wireless charging method for the wireless power transmitter includes a first foreign matter detection step (S2905, S290 6) may be included. For example, the first foreign substance detection step may include the foreign substance detection method of FIG. That is, the wireless power transmitter can be configured to operate as long as the measured Q value is equal to or less than the critical Q value. In another example, the first foreign substance detection step may include: The foreign substance detection method may be the same as that of Fig. 23. That is, the wireless power transmitter detects the measured If the equivalent series resistance is equal to or greater than the first critical equivalent series resistance, it is determined that a foreign substance is present. If the S2906 detects the presence of a foreign substance, the wireless power transmitter will stop wireless charging. In this case, the wireless power transmitter detects the presence of a foreign substance and stops the operation (S2907). The information indicating that a foreign substance has been detected can be transmitted to the wireless power receiver. do.

[0393] In the wireless charging method for the wireless power transmitter, it is determined that no foreign matter is present in the first foreign matter detection. Then, a second foreign substance detection step (S2908, S2909) may be included. The detection step may be the same as the second foreign substance detection method of FIG. 26. That is, The measured peak frequency is not greater than the critical peak frequency, or the measured equivalent series resistance is The resistance is less than the second critical equivalent series resistance and the measured peak frequency is equal to the critical peak frequency. If the value is equal to or greater than the second foreign substance, it can be determined that no foreign substance is present. If it is determined through substance detection that no foreign substance is present, wireless charging can be performed (S2 910). In this case, the wireless power transmitter transmits information indicating that no foreign matter is detected. On the other hand, the wireless power transmitter can transmit the measured peak frequency to the wireless power receiver. The wave number is greater than or equal to the critical peak frequency and the measured equivalent series resistance is equal to the second critical equivalent series resistance. If the value is not less than the threshold, it can be determined that a foreign substance is present. 2. Wireless charging can be stopped if foreign matter is detected through foreign matter detection. (S2907). In this case, the wireless power transmitter transmits information indicating that a foreign substance has been detected. It can be transmitted to a wireless power receiver.

[0394] Therefore, in yet another embodiment, foreign substances can be accurately determined. The embodiment accurately detects foreign substances and prevents heat generation, reduced charging efficiency, and wasted power consumption. In yet another embodiment, a wireless power transmitter and a wireless power receiver are connected to each other. By distinguishing between an increase in the charging distance and the presence of foreign matter, unnecessary This can solve the problem of wireless charging not working.

[0395] The method according to the above-described embodiment is produced as a program to be executed by a computer. The computer can read the information and store it on a computer-readable recording medium. Examples of recording media that can be read by the computer include ROM, RAM, CD-ROM, magnetic These include magnetic tape, floppy disks, and optical data storage devices, as well as carrier wave This also includes those embodied in the form of (for example, transmission over the Internet).

[0396] The computer-readable recording medium is a computer program that can be read by computers connected via a network. distributed across a data system, storing computer-readable code in a distributed manner. The functional program for implementing the above-described method is stored and executed. The program, code, and code segments may be implemented by a programmer skilled in the art to which the embodiments pertain. It can be easily inferred.

[0397] The present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention. It will be understood by those skilled in the art that this is possible.

[0398] Therefore, the above detailed description should not be construed in any way as limiting, but as illustrative and exemplary. The scope of the present invention should be considered as a reasonable interpretation of the appended claims. The scope of the present invention is to be determined by the interpretation of the present invention, and all modifications within the scope of the present invention are within the scope of the present invention. is included in the bracket.

Claims

1. A wireless charging method for a wireless power transmitter, comprising: sensing an object in a charging area; Measuring a Quality Factor Value (QFV); receiving information including a reference Q value; detecting foreign matter using the measured Q value and a reference Q value; Depending on whether the foreign substance is detected, a response signal including ACK or NAK information is transmitted. The stage of believing, Including, If the response signal includes ACK information, the wireless power transmitter sets a first guaranteed power value (guaran If the response signal includes NAK information, the second protection transmit information including the certified power value; The first guaranteed power value is greater than the second guaranteed power value.

2. measuring an internal temperature of the wireless power transmitter; If the response signal includes NAK information, the temperature measured for a preset period is transmitting information including a third guaranteed power value when the temperature is lower than the predetermined temperature; The wireless charging method according to claim 1 , wherein the third guaranteed power value is greater than the second guaranteed power value. Law.

3. The wireless power transmitter according to claim 1 , wherein the second guaranteed power value is a minimum guaranteed power of the wireless power transmitter. Wireless charging method.

4. The step of detecting the foreign substance comprises: determining a critical Q value using the reference Q value; If the measured Q value is equal to or greater than the critical Q value, it is determined that no foreign matter is present. and determining that a foreign substance is present if the detected Q value is less than the critical Q value. Item 1. The wireless charging method according to item 1.

5. 5. The wireless communication device according to claim 4, wherein the critical Q value is smaller than the reference Q value by a first percentage. Line charging method.

6. comparing the reference Q value with a preset Q value of the wireless power transmitter; If the reference Q value is smaller than the preset Q value of the wireless power transmitter, wireless charging is stopped. and ceasing.

7. The step of stopping the wireless charging is performed when the response signal includes NAK information.

6. The wireless charging method according to claim 6.

8. The step of detecting the foreign substance comprises: If the measured Q value is smaller than a value that is smaller than the critical Q value by a second percentage, wireless charging is performed. The wireless charging method of claim 4 , further comprising the step of stopping charging.

9. When transmitting information including the second guaranteed power value, the measured Q value is equal to the critical Q value. and is greater than a value that is smaller than the reference Q value by a second percentage. The wireless charging method described.

10. 3. The step of transmitting the guaranteed power having the third guaranteed power value is performed in a renegotiation step. The wireless charging method described in

11. When the information including the first guaranteed power value is transmitted, the correction step is performed and then the power transmission step is performed. Go, When the information including the second guaranteed power value is transmitted, the power transmission step is performed without performing the correction step. The wireless charging method of claim 1 , wherein the step of

12. The correction step comprises: Received power information from a wireless power receiver, and determined loss power based on the received power information. The wireless charging method of claim 11 , comprising determining:

13. The power transfer step includes: receiving a control error signal from a wireless power receiver and controlling the transmission power, 12. The wireless charging method according to claim 11.

14. an inverter that converts DC power into AC power; a transmitting coil to which the AC power is applied; a communication unit that demodulates a signal modulated from the wireless power receiver; a sensing unit that senses the voltage of the transmitting coil; a control unit that receives information output from the communication unit and the sensing unit; Including, The control unit When an object in the charging area is detected, the Q value is calculated using the information output from the sensing unit. and storing at least one measurement variable of the peak frequency; At least one of the Q value and the peak frequency is determined by using the information output from the communication unit. receiving a foreign matter status packet including a reference factor; Detecting foreign substances using the reference factors and the measurement variables; Depending on whether the foreign substance is detected or not, a response signal including ACK or NAK information is transmitted. The wireless power signal is transmitted to the wireless power receiver. If the response signal includes ACK information, the response signal includes information including a first guaranteed power value. If the signal includes NAK information, transmitting information including a second guaranteed power value; The first guaranteed power value is greater than the second guaranteed power value.

15. the sensing unit measures an internal temperature of the wireless power transmitter; If the response signal includes NAK information, the control unit If the temperature is lower than the preset temperature, the wireless power receiver is requested to renegotiate. , and transmitting information including a third guaranteed power value to the wireless power receiver; The wireless power supply according to claim 14 , wherein the third guaranteed power value is greater than the second guaranteed power value. Transmitter.

16. 15. The method according to claim 14, wherein the second guaranteed power value is a minimum guaranteed power of the wireless power transmitter. Wireless power transmitter.

17. The control unit determines a critical Q value using a reference Q value constituting the reference factor, If the measured Q value is equal to or greater than the critical Q value, it is determined that there is no foreign material.

15. The wireless communication device of claim 14, wherein if the value is less than the critical Q value, it is determined that a foreign substance is present. Power transmitter.

18. 18. The method of claim 17, wherein the critical Q value is a value that is smaller than the reference Q value by a first percentage. Wireless power transmitter.

19. The control unit is configured to determine a reference Q value constituting the reference factor and a predetermined value of the wireless power transmitter. If the reference Q value is smaller than the preset Q value of the wireless power transmitter, 20. The wireless power transmitter of claim 17, wherein wireless charging is stopped when

20. The control unit controls the measured Q value to be smaller than a value that is smaller than the critical Q value by a second percentage.

20. The wireless power transmitter of claim 19, wherein wireless charging is discontinued if the power supply is not connected to the power source.

21. When the control unit transmits information including the second guaranteed power value, The measured Q value is less than the critical Q value and is less than the reference Q value by a second percentage.

21. The wireless power transmitter of claim 20, wherein the value is greater than the value.

22. the control unit receives a control error signal from the wireless power receiver and controls transmission power; When the control unit transmits information including a first guaranteed power value, the control unit controls the transmission power. before receiving the received power information from the wireless power receiver, The power loss is calculated and stored, and based on the calculated power loss, it is determined whether or not a foreign substance is present. 、 When the control unit transmits information including the second guaranteed power value, the control unit calculates the loss power. Whether or not a foreign substance exists is determined based on the received power information without extracting and storing the information. The wireless power transmitter of claim 14 .

23. a receiving coil for receiving wireless power; a rectifier coupled to the receiving coil; a converter coupled to the rectifier; The voltage output from the rectifier is sensed, and the sensed voltage is transmitted to the wireless power transmitter. a control unit that controls the intensity of the power applied to the Including, The control unit transmitting a foreign substance detection status packet from the wireless power transmitter; receiving a response signal corresponding to the foreign substance detection status packet; If the response signal is a NAK signal, the power request signal corresponding to the minimum guaranteed power is transmitted to the a power transmission step of transmitting to a line power transmitter and transmitting power to the wireless power transmitter without performing a correction step; Moving to If the response signal is an ACK signal, a power request signal equal to or greater than the minimum guaranteed power is transmitted to the wireless radio. and then performs a correction step with the wireless power transmitter, and then transitions to a power transmission step. A wireless power receiver.

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