Wireless power transmitter robust to distance from wireless power receiver, and wireless power transmission method using same

Abstract

According to one aspect of the present invention, a mewireless power transmission method using a wireless power transmitter robust to distance from a wireless power receiver is provided, the wireless power transmission method comprising the steps of: calculating an estimated coupling coefficient; calculating a threshold quality factor on the basis of the calculated estimated coupling coefficient; and detecting an external object by referring to the calculated threshold quality factor.

Description

A wireless power transmitter robust to distance from a wireless power receiver and a wireless power transmission method using the same

[0001] The present invention relates to a wireless power transmission method using a wireless power transmitter that is robust to distance from a wireless power receiver.

[0002] The Wireless Power Consortium (WPC), an international standards organization for wireless power transmission, is developing the Qi standard for wireless charging. When developing wireless power transmitters and receivers, compliance with the Qi standard is essential to ensure compatibility, increase product adoption, and ensure stability and quality.

[0003] According to the Qi standard, the power signal of a wireless power transmitter should only interact with a wireless power receiver. However, metallic objects such as coins, paper clips, keys, or aluminum foil can often be placed next to or between a wireless power receiver and a wireless power transmitter. These metallic objects that interfere with power transfer are called foreign objects. According to the Qi standard, a process called foreign object detection (FOD) must be performed to detect these foreign objects to prevent a decrease in power transfer efficiency or the occurrence of accidents such as fire due to these foreign objects.

[0004] Meanwhile, the wireless power transmitter includes an interface, which is a portion where a coil for performing wireless power and a wireless power receiver are placed, and the coil-interface gap, which is defined as the distance between the coil and the upper portion of the interface, can have a significant impact on the accuracy of the aforementioned external material detection process.

[0005] Unlike home wireless chargers, vehicle wireless chargers require a larger coil-interface gap, primarily due to heat dissipation within the vehicle or various mechanical / structural issues. Specifically, the coil-interface gap for home wireless chargers is typically 1.2 mm as exemplified by the Qi standard, whereas there is a strong industry demand for increasing the coil-interface gap for vehicle wireless chargers to 2.0 mm due to the aforementioned issues. However, the inventors of the present invention have confirmed that although conventional foreign substance detection methods can detect foreign substances with effective accuracy when the coil-interface gap is 1.2 mm, the accuracy drops drastically to the point where it becomes unapplicable when the coil-interface gap is changed to, for example, 2.0 mm.

[0006] Accordingly, the inventors of the present invention propose a method for detecting a foreign substance that can always detect a foreign substance with high accuracy regardless of the distance between a wireless power transmitter and a wireless power receiver or the coil-interface gap, and a wireless power transmitter that can perform the method and is robust to the coil-interface gap, and propose a method for performing wireless power transmission robustly regardless of the distance to a wireless power receiver using the wireless power transmitter.

[0007] The purpose of the present invention is to solve all of the problems of the above-mentioned prior art.

[0008] In addition, another object of the present invention is to provide a method for detecting a foreign substance that is robust to the distance between a wireless power receiver and a wireless power transmitter or the coil-interface gap.

[0009] In addition, another object of the present invention is to provide a method for detecting a foreign substance with high accuracy regardless of the distance between a wireless power receiver and a wireless power transmitter or a change in the coil-interface gap, thereby providing a method for variously changing the coil-interface gap in a wireless power transmitter.

[0010] A representative configuration of the present invention to achieve the above purpose is as follows.

[0011] According to one aspect of the present invention, a wireless power transmission method is provided, including a step of calculating an estimated coupling coefficient, a step of calculating a limit quality factor based on the calculated estimated coupling coefficient, and a step of detecting a foreign substance with reference to the calculated limit quality factor.

[0012] According to another aspect of the present invention, a wireless power transmission system is provided, including an estimated coupling coefficient calculation unit for calculating an estimated coupling coefficient, a limit quality coefficient calculation unit for calculating a limit quality coefficient based on the calculated estimated coupling coefficient, and a foreign substance detection unit for detecting a foreign substance with reference to the calculated limit quality coefficient.

[0013] According to another aspect of the present invention, a wireless power transmission method is provided, including the steps of calculating an estimated coupling coefficient in response to a wireless power transmitter receiving a first packet containing information necessary for calculating an estimated coupling coefficient from a wireless power receiver, calculating a marginal quality factor based on the second packet and the calculated estimated coupling coefficient in response to a wireless power receiver receiving a second packet containing information necessary for calculating a marginal quality factor, and detecting a foreign substance with reference to the calculated marginal quality factor.

[0014] According to another aspect of the present invention, a wireless power transmitter is provided that calculates an estimated coupling coefficient in response to receiving a first packet containing information necessary for calculating an estimated coupling coefficient from a wireless power receiver, calculates a marginal quality factor based on the second packet and the calculated estimated coupling coefficient in response to receiving a second packet containing information necessary for calculating a marginal quality factor from the wireless power receiver, and detects a foreign substance with reference to the calculated marginal quality factor.

[0015] According to another aspect of the present invention, a wireless power transmission method is provided, including a step of transmitting a first packet containing information necessary for calculating an estimated coupling coefficient to a wireless power transmitter, a step of transmitting a second packet containing information necessary for calculating a marginal quality factor to the wireless power transmitter, and a step of requesting transmission of a detection result of a foreign substance calculated by the wireless power transmitter.

[0016] According to another aspect of the present invention, a wireless power receiver is provided that transmits a first packet containing information necessary for calculating an estimated coupling coefficient to a wireless power transmitter, transmits a second packet containing information necessary for calculating a marginal quality factor, and requests transmission of a detection result of an external substance calculated by the wireless power transmitter.

[0017] In addition, other wireless power transmitters, other wireless power receivers and other wireless power transmission methods for implementing the present invention are further provided.

[0018] According to the present invention, it is possible to provide a method for detecting external substances that is robust to the distance between a wireless power receiver and a wireless power transmitter or the coil-interface gap.

[0019] In addition, the present invention provides a method for detecting a foreign substance with high accuracy regardless of the distance between a wireless power receiver and a wireless power transmitter or changes in the coil-interface gap, thereby providing a method for variously changing the coil-interface gap in a wireless power transmitter.

[0020] FIG. 1 is a drawing exemplarily showing an exploded view of a wireless power transmitter according to one embodiment of the present invention.

[0021] FIG. 2 is a drawing exemplarily showing the configuration of a wireless power transmission system according to one embodiment of the present invention.

[0022] FIG. 3 is a diagram exemplarily showing coefficients of a kQ slope implemented according to one embodiment of the present invention.

[0023] FIG. 4 is a diagram exemplifying a scaling factor that can be applied to a kQ slope implemented according to one embodiment of the present invention.

[0024] FIG. 5 is a diagram exemplarily showing standard deviation and fitting error implemented according to one embodiment of the present invention.

[0025] FIG. 6 is a drawing exemplarily showing a kQ slope implemented according to one embodiment of the present invention.

[0026] FIG. 7 is a diagram exemplarily showing the structure of a first packet according to one embodiment of the present invention.

[0027] FIG. 8 and FIG. 9 are diagrams exemplarily showing the structure of a second packet according to one embodiment of the present invention.

[0028] FIG. 10 is a diagram exemplarily showing the structure of a request packet that a receiver can transmit to a transmitter according to one embodiment of the present invention.

[0029] FIG. 11 is a diagram exemplarily showing the structure of a response packet to a request packet according to one embodiment of the present invention.

[0030] FIG. 12 is a drawing exemplarily showing the results of evaluating the accuracy of a foreign substance detection method according to one embodiment of the present invention and a conventional foreign substance detection method.

[0031] <Explanation of symbols>

[0032] 110 Transmitter interface section

[0033] 120 Transmitter Coil

[0034] 130 Bottom part of the transmitter

[0035] 200 Wireless Power Transfer System

[0036] 210 Estimated Coupling Coefficient Calculation Section

[0037] 220 Limit Quality Factor Calculation Section

[0038] 230 Foreign Material Detection Unit

[0039] 240 Communications Department

[0040] 250 Control Unit

[0041] The following detailed description of the present invention refers to the accompanying drawings, which illustrate specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention, while different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be modified and implemented from one embodiment to another without departing from the spirit and scope of the present invention. Furthermore, it should be understood that the positions or arrangements of individual components within each embodiment may also be modified without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is to be construed to encompass the scope of the claims and all equivalents thereof. Like reference numerals in the drawings represent the same or similar elements throughout the several aspects.

[0042] Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the attached drawings so that a person having ordinary skill in the art to which the present invention pertains can easily practice the present invention.

[0043] Conventional foreign substance detection methods

[0044] The foreign object detection or foreign object detection method according to one embodiment of the present invention may refer to a method for detecting a foreign object (FO) that may affect transmission efficiency or cause excessive heat generation when performing wireless power transfer. Conventionally, foreign object detection could be performed through the Mated-Q method or the Mated-Q-Distance method.

[0045] First, the Mated-Q method may refer to a method of detecting a foreign substance by comparing the cases where a wireless power receiver (hereinafter, a "receiver" or "PRx") is not placed on a wireless power transmitter (hereinafter, a "transmitter" or "PTx") and the cases where a wireless power receiver (hereinafter, a "receiver" or "PRx") is placed. Specifically, the Mated-Q method may refer to a method of detecting a foreign substance by using an Open-Air Q-test algorithm that detects a foreign substance in response to the receiver not being coupled to the transmitter, mapping resonant frequency and Q deflection data to a two-dimensional space for the cases where there is no foreign substance and the cases where there is a foreign substance, respectively, and calculating a threshold using a logistic regression analysis method, and comparing the threshold and the measured value.

[0046] Next, the mated-Q-distance method can mean a method of detecting external substances by mapping the resonance frequency and resistance deflection data to a two-dimensional space in the case of no external substances, calculating a linear curve using a linear regression analysis method, applying an error margin to the calculated linear curve to calculate a threshold, and comparing the threshold and measured values.

[0047] However, all of the conventional foreign substance detection methods described above have an accuracy that can be practically applied only when the distance between the transmitter and receiver or the coil-interface gap has a specific value (e.g., 1.2 mm), and have a problem in that the accuracy drops significantly when the gap described above changes.

[0048] Coil-interface gap

[0049] A wireless power transmission method according to one embodiment of the present invention can robustly detect external substances in response to changes in the distance (interval) between a receiver and a transmitter. The distance between the receiver and the transmitter is referred to as the "coil-interface gap ( ) can be defined as.

[0050] A coil according to one embodiment of the present invention may refer to a coil included in a transmitter, which may refer to a component for generating a magnetic field to wirelessly transmit energy, and an interface may refer to a component on which a receiver is placed when the receiver is coupled (contacted) to perform wireless power transmission as a part of the transmitter.

[0051] Referring to Fig. 1, which exemplarily illustrates an exploded view of a transmitter, the interface part (110) of the transmitter is an upper part distinct from the lower part (130) of the transmitter, between which the coil (120) of the transmitter can be positioned, and each part can have a layered structure and be assembled. Here, the distance between the interface part (110) of the transmitter and the coil (120) of the transmitter, corresponding to the final proper assembly of each part, is the coil-interface gap ( ) can mean.

[0052] Meanwhile, the above-mentioned coil-interface gap ( ) needs to be larger in vehicle wireless chargers compared to home wireless chargers. This is due to the coil-interface gap ( ) inside the vehicle, due to heat dissipation and mechanical or structural issues (e.g., different housing thicknesses or need for anti-slip pads). ) needs to be designed to be larger than the example (i.e., 1.2 mm) presented in the conventional Qi standard. For example, foreign material detection according to one embodiment of the present invention may be performed by using a coil-interface gap ( ) can also be applied when the coil-interface ( ) spacing is only exemplary, and the wireless power transmission method or the external material detection method according to one embodiment of the present invention may have various coil-interface spacings ( ) can be applied to all.

[0053] Wireless power transmission according to the present invention

[0054] Hereinafter, in relation to a wireless power transmission method according to one embodiment of the present invention, a wireless power transmission system, a wireless power transmitter and a wireless power receiver capable of implementing the wireless power transmission system, and a wireless power transmission method using the same will be examined.

[0055] Wireless Power Transfer System

[0056] Below, the internal configuration and functions of each component of the wireless power transmission system (200) that performs important functions for implementing the present invention will be examined.

[0057] FIG. 2 is a drawing showing in detail the internal configuration of a wireless power transmission system (200) according to one embodiment of the present invention.

[0058] As illustrated in FIG. 2, a wireless power transmission system (200) according to an embodiment of the present invention may be configured to include an estimated coupling coefficient calculation unit (210), a marginal quality factor calculation unit (220), a foreign material detection unit (230), a communication unit (240), and a control unit (250). According to an embodiment of the present invention, at least some of the estimated coupling coefficient calculation unit (210), the marginal quality factor calculation unit (220), the foreign material detection unit (230), the communication unit (240), and the control unit (250) may be program modules that communicate with an external system (not shown). These program modules may be included in the wireless power transmission system (200) in the form of an operating system, an application program module, or other program modules, and may be physically stored in various known memory devices. In addition, these program modules may also be stored in a remote memory device capable of communicating with the wireless power transmission system (200). Meanwhile, these program modules include, but are not limited to, routines, subroutines, programs, objects, components, data structures, etc. that perform specific tasks or execute specific abstract data types, as described later in accordance with the present invention.

[0059] Meanwhile, although the wireless power transmission system (200) has been described as above, this description is exemplary, and it is obvious to those skilled in the art that at least some of the components or functions of the wireless power transmission system (200) may be realized within a server (not shown) or included within an external system (not shown) as needed.

[0060] First, the estimated coupling coefficient calculation unit (210) according to one embodiment of the present invention can perform a function of calculating an estimated coupling coefficient.

[0061] The coupling coefficient according to one embodiment of the present invention is a coefficient indicating the degree of coupling between two coils or inductors. Specifically, the coupling coefficient ( )Is It can be obtained according to the following formula ( is the mutual inductance when the transmitter and receiver are coupled, is the self-inductance of the transmitter when the transmitter and receiver are coupled, is the self-inductance of the receiver when the transmitter and receiver are coupled.

[0062] Estimated coupling coefficient according to one embodiment of the present invention ( ) may mean a coupling coefficient estimated corresponding to a general transmitter and a general receiver.

[0063] According to one embodiment of the present invention, a general transmitter (general PTx) or a general receiver (general PRx) may refer to an unknown transmitter device or receiver device whose specific details are unknown. Meanwhile, a general transmitter may be expressed as "T" or a general device, and a general receiver may be expressed as "R" or (same as a general transmitter) a general device.

[0064] Additionally, compared to the above-described general transmitter and general receiver, a reference transmitter (reference PTx) or reference receiver (reference PRx), which may also be referred to as a system-model transmitter or system-model receiver, may refer to a transmitter device or receiver device that knows specific details. Meanwhile, a reference transmitter or reference receiver may be expressed identically as "G" or a reference device.

[0065] Continuing, in the case where both the transmitter and the receiver are general devices, it is necessary to accurately estimate coefficients, formulas or numerical values ​​that can be used for wireless power transmission or foreign material detection, since all specific details about both devices are unclear. Therefore, various coefficients, formulas or numerical values ​​used in connection with the wireless power transmission method, the wireless power transmission system, the wireless power transmitter and the wireless power receiver according to an embodiment of the present invention can be basically calculated by experimentally obtaining coefficients, formulas or numerical values ​​corresponding to the case where both the transmitter and the receiver are reference devices, and then estimating coefficients, formulas or numerical values ​​corresponding to the case where at least one of the transmitter and the receiver is a general device (i.e., reflecting actual usage patterns).

[0066] Continuing, specifically, the estimated coupling coefficient ( )Is and It can be estimated through the following formula. Specifically, are the coefficients (unique coefficients) calculated for the reference transmitter and reference receiver, and the x-axis is , y-axis It can mean the slope of a linear curve produced through linear regression analysis on multiple measurement values. can mean the intercept of the above-mentioned straight line. Meanwhile, may refer to the digital ping voltage reported by the receiver, may refer to the measured peak to peak transmitter resonant capacitor voltage (peak to peak CTX voltage), may refer to the measured DC voltage for the inverter.

[0067] More specifically, the estimated coupling coefficient ( ) can be estimated by further utilizing an eco-system scaling factor together with the above-described intrinsic coefficient. The eco-system scaling factor may refer to a coefficient applied to correct for differences in the slope and intercept of the above-described straight line derived in response to the case where at least one of the transmitter and the receiver is a general device, considering that such differences are different from the above-described intrinsic coefficient. That is, by additionally utilizing the eco-system scaling factor based on the intrinsic coefficient, the slope and intercept of the straight line in the case where both the transmitter and the receiver are reference devices can be corrected, thereby estimating the slope and intercept of the straight line in the case where at least one of the transmitter and the receiver is a general device.

[0068] Meanwhile, the estimated coupling coefficient when further utilizing the above-mentioned ecosystem scaling factor ( )Is, can be obtained through the formula. Here, the unique coefficient is , and a being 0 means that the corresponding eigencoefficient is for the slope of the straight line, a being 1 means that the corresponding eigencoefficient is for the intercept of the straight line, b being g means that the eigencoefficient is for the transmitter being a reference device, b being x means that the eigencoefficient is for the transmitter being a general device, c being g means that the eigencoefficient is for the receiver being a reference device, and c being y means that the eigencoefficient is for the receiver being a general device. That is, can mean that the unique coefficient representing the slope of the straight line when the transmitter is a general device and the receiver is a reference device, may mean that the unique coefficient representing the intercept of the straight line when the transmitter is a general device and the receiver is a reference device.

[0069] Meanwhile, in the above formula and may refer to the ecosystem scaling factor used to estimate the coupling coefficient. Specifically, the estimated coupling coefficient ( ) is the ecosystem scaling factor for It can be expressed as , and d being 0 can mean that the corresponding ecosystem scaling coefficient is for the slope of the straight line, and d being 1 can mean that the corresponding ecosystem scaling coefficient is for the intercept of the straight line. Is It can be calculated by the following formula: Is It can be determined according to the following formula.

[0070] Next, the limit quality coefficient calculation unit (220) according to one embodiment of the present invention calculates the estimated coupling coefficient ( ) based on the marginal quality factor ( ) can perform the function of producing.

[0071] Quality factor according to one embodiment of the present invention ( ) is generally a coefficient indicating a measure of the quality of a circuit or system, and may specifically mean a coefficient indicating the quality of wireless power transmission according to one embodiment of the present invention.

[0072] Limit quality factor according to one embodiment of the present invention ( ) is the measurement quality factor ( ) can mean a quality factor (or its value) that serves as a standard for judging the presence of external substances by comparing it with the limit quality factor ( ) will be described in detail later.

[0073] Continuing, the marginal quality factor calculation section calculates the estimated coupling factor ( ) based on the estimated quality factor ( ) and the estimated quality factor ( ) based on the marginal quality factor ( ) can perform the function of producing.

[0074] Estimated quality factor according to one embodiment of the present invention ( ) may mean an estimated value of the quality factor. The estimated coupling coefficient ( ), estimating the quality factor can be derived in a way that the quality factor is estimated in the case where both the transmitter and the receiver are general devices based on experimental values ​​in the case where at least one of the transmitter and the receiver is a reference device.

[0075] Below, the estimated quality factor ( ) is to be described. A quality factor ( according to one embodiment of the present invention ) is the coupling coefficient ( ) can be expressed as a straight line with a specific slope and a specific intercept (i.e., ) In this way, the quality factor ( ) and coupling coefficient ( ) for the slope of the straight line function ( ) and intercept ( ), the estimated coupling coefficient ( ) based on the estimated quality factor ( ) can be produced.

[0076] If we continue, the estimated quality factor ( ) is the estimated coupling coefficient ( ) and estimated quality factor ( ) and estimated coupling coefficient ( ) can be calculated based on the first coefficient representing the relationship.

[0077] As described above, the estimated quality factor according to one embodiment of the present invention ( )Is, = can be expressed as a linear function for the coupling coefficient, i.e., the first coefficient described above is and can mean. Here, can mean the slope of a straight line as a coefficient corresponding to the fact that both the transmitter and receiver are general devices, can mean the intercept of a straight line as a coefficient corresponding to the fact that both the transmitter and receiver are general devices.

[0078] According to one embodiment of the present invention, an estimated quality factor ( ) is produced as described above. and By estimating the above formula = This may mean estimating.

[0079] Specifically, the first coefficient may be calculated based on one or more second coefficients and a scaling factor calculated through regression analysis corresponding to at least one of the wireless power transmitter and the wireless power receiver being a reference device.

[0080] Specifically, the second coefficient and scaling factor can be derived by applying regression analysis to experimental values ​​for each of the following cases: when both the transmitter and receiver are reference devices, when the transmitter is a general device and the receiver is a reference device, and when the transmitter is a reference device and the receiver is a general device. The regression method described above may include, but is not limited to, linear regression and logistic regression methods.

[0081] First, according to the linear regression analysis method, the first coefficient ( and ) is derived by (1) the relationship between the quality factor and the coupling factor in the case where both the transmitter and the receiver are reference devices (i.e., ), (2) The relationship between the quality factor and the coupling factor in the case where the transmitter is a general device and the receiver is a reference device (i.e., ), and (3) the relationship between the quality factor and the coupling factor in the case where the transmitter is a reference device and the receiver is a general device (i.e., ) is first derived, and the second coefficient derived through this, i.e. the slope in (1) to (3) above ( , , ) and intercept ( , , ) can be performed by calculating based on the following.

[0082] Specifically, is a scaling factor (or ecosystem scaling factor) derived based on the slope and intercept of (1) to (3) described above. and can be produced through, and more specifically, silver (Here, ) can be calculated through the relationship, silver (Here, ) can be calculated through the relationship. In summary, the estimated quality factor ( )Is = It can be calculated through a formula such as:

[0083] one side, Is Instead of the relationship, It can also be obtained through the relationship. In this case, the estimated quality factor ( )Is = It can be calculated through a formula such as:

[0084] Continuing, the first coefficient ( according to the logistic regression analysis method) , and ) is derived from (1) the decision boundary coefficients in the case where both the transmitter and receiver are reference devices. , , , (2) The decision boundary coefficient in the case where the transmitter is a general device and the receiver is a reference device. , , and (3) the decision boundary coefficient in the case where the transmitter is a reference device and the receiver is a general device. , , This can be done by first deriving the scaling factor, the ecosystem scaling factor, from which the scaling factor is derived.

[0085] Specifically, the first coefficient ( , and ) and the corresponding ecosystem scaling factor ( , and ) is obtained, and among the second coefficients, the decision boundary coefficient in the case where the transmitter is a general device and the receiver is a reference device , , By applying each of them, the first coefficient can be finally obtained. More specifically, Is It can be obtained by the following formula, silver It can be obtained according to the following formula: Is It can be obtained according to the following formula. Meanwhile, in case of using the logistic regression method, the error margin ( ) is not necessary, so the marginal quality factor ( ) can be derived. In conclusion, the marginal quality factor ( determined by the logistic regression method) ) can be expressed as follows:

[0086]

[0087] Continuing, the marginal quality factor calculation section calculates the estimated coupling factor ( ) with error margin ( ) based on the marginal quality factor ( ) can perform the function of producing.

[0088] The error margin according to one embodiment of the present invention may refer to a margin of error designed to compensate for the variability and uncertainty of measured values ​​and ensure safe and reliable operation of the system. By applying the error margin, the occurrence of false negative and false positive results in foreign substance detection can be minimized. Furthermore, this error margin applies only when the second and first coefficients described above are calculated through linear regression analysis, and may not apply when calculated through logistic regression analysis.

[0089] According to one embodiment of the present invention, the estimated coupling coefficient ( ) with error margin ( ) based on the marginal quality factor ( ) is calculated by calculating the estimated coupling coefficient ( ) through the estimated quality factor ( ) is calculated, and the error margin ( is calculated from the quality factor. ) by subtracting the marginal quality factor ( ) can mean finding the marginal quality factor ( )Is, It can be calculated using the following formula.

[0090] Continuing, the error margin according to one embodiment of the present invention ( ) is, for example, (1) , or (2) can be defined as follows.

[0091] Hereinafter, the above-described (1) is referred to as the “first error margin calculation method”, and the above-described (2) is referred to as the “second error margin calculation method”.

[0092] Specifically, in the first error margin calculation method described above, is the measured actual quality factor ( ) and the estimated quality factor ( calculated using the above formula) ) can mean the standard deviation between is when both the transmitter and receiver are reference devices (GG). and if the transmitter is a reference device and the receiver is a general device (GR). It can mean the maximum value among, is when the transmitter is a general device and the receiver is a reference device (TG). It can mean the maximum value among them. That is, silver and It can mean the value obtained by multiplying the maximum value by 3.

[0093] Continuing, in the second error margin calculation method described above, is the measured actual quality factor ( ) and the estimated quality factor ( calculated using the above formula) ) can mean the maximum value among the deviations between (i.e., the maximum fitting error), is when both the transmitter and receiver are reference devices (GG). (in other words, ) and if the transmitter is a reference device and the receiver is a general device (GR). (in other words, ) can mean the maximum value, is when the transmitter is a general device and the receiver is a reference device (TG). (in other words, ) can mean the maximum value, may imply additional transmitter manufacturing tolerance, may mean the fitting error margin, can mean the standard deviation of a distribution in Monte-Carlo simulation, may mean the scaling error margin. Meanwhile, the above-mentioned can have a default value of 0.2, as described above. can have a default value of 5.

[0094] In conclusion, the estimated quality factor ( ) to offset the effect of estimation errors that occur in the process of producing the error margin ( ) can be used, and specifically, the error margin ( calculated by the first error margin calculation method or the second error margin calculation method described above) ) is the estimated quality factor ( ) is the marginal quality factor calculated by subtracting from ) can be used to offset the effects of estimation errors.

[0095] Next, the external material detection unit (230) according to one embodiment of the present invention calculates the calculated limit quality factor ( ) can perform the function of detecting external substances.

[0096] Foreign object detection (FOD) according to one embodiment of the present invention may mean detecting a metallic substance (i.e., a foreign substance) that exists near or between a transmitter and a receiver before or during wireless power transmission, thereby interfering with the power signal transmitted by the wireless power transmitter and generating excessive heat upon receiving the power signal. Such a metallic substance may be an everyday metallic substance that may be placed near the wireless power transmitter and receiver, such as, but not limited to, coins, paper clips, keys, or aluminum foil.

[0097] Meanwhile, a metallic material that interferes with the same power signal but is part of the transmitter and receiver and is not an external material that interferes with the power signal can be called a friendly metal (FM). Unlike the aforementioned external materials, the friendly metal should not be detected by external material detection. In other words, in the external material detection, it may be necessary to detect only the external materials that interfere with the actual wireless power transmission, excluding the friendly metal.

[0098] Meanwhile, a method for detecting a foreign substance according to one embodiment of the present invention is provided by a method for detecting a foreign substance by a distance between a transmitter and a receiver or a coin-interface distance ( ) is a coefficient that includes the variable as a coupling coefficient ( ) to detect external substances, unlike the conventional external substance detection method described above, the coin-interface gap ( ) can always perform detection of foreign substances with high accuracy even if the distance between the coin and the interface is changed. For example, the conventional foreign substance detection method described above can detect foreign substances with high accuracy at the coin-interface distance ( defined as an example in the Qi standard. ) can detect foreign substances with relatively high accuracy for cases where the size is 1.2 mm, but the coin-interface gap ( ) is not 1.2 mm, i.e., in the case of 2.0 mm, the accuracy is drastically reduced, and the frequency of false negatives or false positives is so high that it cannot be applied to an actual foreign substance detection method. However, the foreign substance detection method according to one embodiment of the present invention is applicable to various coin-interface intervals ( ), i.e., the coin-interface gap ( ) can detect foreign substances with high accuracy for both 1.2 mm and 2.0 mm.

[0099] If we continue, the foreign material detection unit will have a measurement quality factor ( ) is the calculated limit quality factor ( ) can detect external substances.

[0100] Specifically, the external material detection unit has a measurement quality factor ( ) is the marginal quality factor ( ) is judged to be free of foreign substances, and the measurement quality factor ( ) is the marginal quality factor ( ) can be judged to be an external substance corresponding to something smaller than that.

[0101] A method for detecting foreign substances according to one embodiment of the present invention is a method for detecting foreign substances using a limit quality factor derived in the above-described manner. ), the measurement quality factor ( ) can be compared with this to determine the presence of external substances. That is, the measurement quality factor ( ) is the limit quality factor ( ) is less than (i.e., < ) can be judged to exist in response to the external substance, and the measurement quality factor ( ) is the limit quality factor ( ) is greater than or equal to (i.e., ≥ ) can be determined that no external material exists. That is, the limit quality factor ( according to one embodiment of the present invention) ) is the combination coefficient through regression analysis ( ) and quality factor ( ) is derived as a linear relationship (i.e., ), and thus the measurement quality factor ( kQ slope form). ) and marginal quality factor ( ) is compared to the size of the coupling coefficient ( ) is the marginal quality factor calculated for the same case. ) and measurement quality factor ( ) can mean comparing the coupling coefficients ( ) and one axis (e.g., y-axis) is the quality factor ( ) based on the kQ slope shown on the plane, the point located at the top is the measurement quality factor ( ) is the limit quality factor ( ) can mean a case where the point located at the bottom is the measurement quality factor ( ) is the limit quality factor ( ) can mean a case where it is less than .

[0102] Continuing, the estimated coupling coefficient described above ( ) is the coil-interface gap ( ) has a negative correlation with the estimated quality coefficient ( ) is the coil-interface gap ( ) may have a positive correlation.

[0103] Coil-interface gap according to one embodiment of the present invention ( ) has already been explained in detail above, so its description is omitted to avoid excessive duplication.

[0104] Estimated coupling coefficient according to one embodiment of the present invention ( ) includes mutual inductance as a variable, and mutual inductance is a function of coil-interface spacing ( ) decreases as the estimated coupling coefficient ( ) is also the coil-interface gap ( ) may decrease as the coefficient of coupling increases, and consequently, the estimated coupling coefficient ( ) is the coil-interface gap ( ) may have a negative correlation.

[0105] Meanwhile, the estimated quality factor ( ) is the coil-interface gap ( ) increases, the gap between the affinity metal (FM) present in the receiver and the transmitter also increases, so the coil-interface gap ( ) may have a positive correlation.

[0106] If we continue, as described above, the quality factor ( ) is the coupling coefficient ( ) can be expressed as a straight line with a specific slope and a specific intercept (i.e., ), and accordingly the quality factor ( ) and coupling coefficient ( ) may have a negative linear relationship with each other (i.e., (is negative).

[0107] Example of deriving marginal quality factor

[0108] Below, the limit quality factor (which is the final judgment criterion) is described in relation to the foreign substance detection method according to one embodiment of the present invention. ) is to be explained by way of example. However, the content described below is only an example, and it is self-evident that each figure and specific calculation method can be changed as needed.

[0109] (1) Derivation of the second coefficient

[0110] First, for each of the cases where the transmitter and receiver are both reference devices (GG), the transmitter is a general device and the receiver is a reference device (TG), and the transmitter is a reference device and the receiver is a general device (GR), the coupling coefficient ( ), and the quality factor for measuring the axis ( ) can be used to derive the second coefficient through regression analysis. For example, the second coefficient derived for each of the above-described cases can be as shown in Fig. 3, and the second coefficient (slope) and (Intercept) can be expressed as follows. In this embodiment, a linear regression analysis method was used to perform the above-described regression analysis, but the present invention is not limited thereto and various regression analysis methods can be applied. For example, a logistic regression method can also be applied.

[0111] (2) Derivation of the first coefficient

[0112] From the second coefficient described above, an ecosystem scaling factor that can be used to derive a first coefficient, which is a coefficient for the case where both the transmitter and the receiver are general devices (TR), can be derived. Applying the ecosystem scaling factor to the second coefficient described above (e.g., the derived ecosystem scaling factor is a coefficient of the first coefficient when the transmitter is a general device and the receiver is a reference device (TG)) , ) by multiplying it by the first coefficient that can be applied when both the transmitter and the receiver are general devices whose specific details are unknown because they have different designs from the reference device. Specifically, among the second coefficients, Eco-system scaling factor applied to (slope) is using the second coefficient described above. It can be obtained through a formula such as , and among the second coefficients Eco-system scaling factor applied to (intercept) is using the second coefficient described above. It can be obtained through a formula such as the following. The finally derived ecosystem scaling factor can be, for example, as shown in Fig. 4.

[0113] (3) Calculation of estimated quality factor

[0114] Using the second coefficient and the ecosystem scaling coefficient calculated above, the first coefficient is calculated, and through this, the coupling coefficient ( ) and quality factor ( ) and obtain the estimated quality factor ( ) can be calculated. For example, the estimated quality factor ( )Is = It can be expressed as follows, and by applying the ecosystem scaling factor and the second factor, the estimated quality factor ( )Is = It can be approximated as follows. If we apply the values ​​obtained above, the estimated quality factor ( ) is, for example, As the coupling coefficient ( ) can be expressed as a relational expression (refer to Figs. 3 and 4 for each figure).

[0115] (4) Calculating error margin

[0116] In response to the use of linear regression method in the calculation of the second coefficient described above, the error margin ( ) can be performed. First, an example of the "first error margin calculation method" among the above-described error margin calculation methods will be explained. In order to calculate the error margin, the standard deviation and the maximum fitting error can be calculated for each of the cases where the transmitter and receiver are both reference devices (GG), the transmitter is a general device and the receiver is a reference device (TG), and the transmitter is a reference device and the receiver is a general device (GR). For example, the calculated standard deviation (" in FIG. 5 ") and the maximum fitting error ("fitting error" in Fig. 5) may be as shown in Fig. 5, and when calculating the error margin using the first error margin calculation method, the standard deviation ( ) can only be used. The standard deviation ( shown in Fig. 5) ) may correspond to the maximum value of the standard deviation (i.e., 0.1999) in the case where both the transmitter and the receiver are reference devices (GG), the maximum value of the standard deviation (i.e., 0.1797) in the case where the transmitter is a general device and the receiver is a reference device (TG), and the maximum value of the standard deviation (i.e., 0.2413) in the case where the transmitter is a reference device and the receiver is a general device (GR). In conclusion, the error margin ( calculated based on the standard deviation of FIG. 5 through the first error margin calculation method) ) are as follows:

[0117]

[0118] Next, the error margin ( based on the maximum fitting error shown in Fig. 5) ) is as follows (used here) for the "second error margin calculation method" , , and is as described above):

[0119]

[0120] (5) Calculation of marginal quality factor

[0121] Finally, the estimated quality factor calculated above ( ) in the error margin ( ) and subtract the marginal quality factor ( ) is produced.

[0122] (6) Results

[0123] Referring to Fig. 6, the coil-interface gap ( ) is 2.0 mm, the kQ slope (650) (i.e., the marginal quality factor ( ) is shown (since the error margins calculated by the first error margin calculation method and the second error margin calculation method are almost the same, the two methods do not show a significant difference on the graph, and therefore, both methods can be used). That is, the measurement values ​​(610) located above the kQ slope (650) are in the case of no external material (no FO), and the measurement values ​​(620) located below are in the case of a foreign material (w / FO). Meanwhile, the corrected kQ slope (640) is obtained by correcting the kQ slope (630) to which the scaling factor is not applied by applying the scaling factor (eco-system scaling factor), and the error margin ( ) can be applied to obtain the kQ slope (650) that can be ultimately used for detecting external substances.

[0124] Below, a description will be given of a wireless power transmitter, a wireless power receiver, and a method for operating them, which perform wireless power transmission or external material detection according to an embodiment of the present invention described above. Meanwhile, any details not specifically mentioned in the description of the wireless power transmitter and wireless power receiver below can be understood to be essentially the same as those described in the wireless power transmission system section above, and their description may be omitted to avoid excessive duplication.

[0125] <Operation of a wireless power transmitter>

[0126] First, the transmitter according to one embodiment of the present invention estimates the coupling coefficient ( ) in response to receiving the first packet containing the information required for calculating the estimated coupling coefficient ( ) can be produced.

[0127] A first packet according to one embodiment of the present invention is a packet transmitted from a receiver to a transmitter, wherein the transmitter estimates a coupling coefficient ( ) may mean a packet containing information that can be obtained by the receiver among the information required to produce the packet.

[0128] The above-mentioned transmitter has an estimated coupling coefficient ( ) Among the information required to produce the information that the receiver can obtain, for example, , and It can be, and the meaning of each character is as described above.

[0129] Meanwhile, the transmitter stores the unique coefficients ( and ), voltage measurement ( and ) and the estimated coupling coefficient ( using the information contained in the first packet described above ) can be produced, and the specific production method is as described above.

[0130] Specifically, the first packet according to one embodiment of the present invention may be an extended identification packet (XID packet) that provides additional information about the ID of the receiver among packets transmitted from the receiver to the transmitter, and for example, the first packet may be a packet having a structure as illustrated in FIG. 7. However, the type or structure of the first packet illustrated in FIG. 7 is exemplary, and it is also possible to use a new packet or change the structure as needed.

[0131] Continuing, the transmitter according to one embodiment of the present invention receives a limit quality factor ( ) in response to receiving a second packet containing information necessary for the calculation of the second packet and the calculated estimated coupling coefficient ( ) based on the marginal quality factor ( ) can be produced.

[0132] A second packet according to one embodiment of the present invention is a packet in which the transmitter has a limit quality factor ( ) may refer to a packet containing information that the receiver can obtain among the information required to produce the quality factor ( ) . That is, the transmitter stores the quality factor ( ) in the transmitter. ) and the marginal quality factor ( based on the second packet received from the receiver. ) can be produced.

[0133] Meanwhile, the above-mentioned limit quality factor ( ) is the information required to calculate the estimated quality factor ( ) and the information required to produce the error margin ( ) may include information necessary to produce the result.

[0134] Continuing, the estimated quality factor (as described above) is included in the information contained in the second packet. ) may be a scaling factor for deriving a formula representing the kQ slope (i.e., a coefficient included in the kQ slope). Specifically, the scaling factor described above is an ecosystem scaling factor. and It could be.

[0135] In conclusion, the transmitter stores the and Wow, the ecosystem scaling factor included in the second packet and The estimated coupling coefficient produced with ( ) to estimate the quality factor ( ) can be produced.

[0136] Next, the error margin included in the second packet described above ( ) is used to calculate the information, if the above-described "first error margin calculation method" is used. It can be done, and if the "second error margin calculation method" described above is used, It can be, and their meanings are as described above.

[0137] Specifically, in response to using the "first error margin calculation method", the transmitter stores Wow, included in the second packet Using the error margin ( ) can be calculated, and corresponding to using the "second error margin calculation method", the transmitter stores the , , and Wow, included in the second packet Using the error margin ( ) can be calculated. Here, the meaning of each character is as described above. Finally, the transmitter calculates the estimated quality factor ( ) and error margin ( ) and the marginal quality factor ( ) can be derived, and external material detection can be performed through this.

[0138] Continuing, the second packet described above may have a structure similar to the packet illustrated in FIG. 8 or FIG. 9, for example. Referring to FIG. 8, a packet configured by adding a new field (800) to an existing PLAP packet may be used as the second packet. Each piece of information included in the second packet may be divided and included in the new field (800) described above. Referring to FIG. 8, may be contained in a field containing B7 to B8 bytes and b0 to b7 bits, is B9 to B 10 It can be included in a field containing bytes and bits b0 to b7, Silver B 11 Inland B 12 It can be included in a field containing bytes and bits b0 to b7.

[0139] As another example, referring to FIG. 9, a packet configured by adding a new field (900) to an existing mated-Q coefficients packet can be used as a second packet. Each piece of information included in the second packet can be divided and included in the new field (900) described above. Referring to FIG. 9, may be contained in a field containing B7 to B8 bytes and b0 to b7 bits, is B9 to B 10 It can be included in a field containing bytes and bits b0 to b7, Silver B 11 Inland B 12 It can be included in a field containing bytes and bits b0 to b7.

[0140] However, the structures of the second packets described in FIGS. 8 and 9 are all exemplary, and it is obvious to those skilled in the art that new packets can be created and used as needed.

[0141] Continuing, the transmitter according to one embodiment of the present invention calculates the marginal quality factor ( ) can be used to detect external substances.

[0142] Wireless Power Transmitter

[0143] A transmitter according to one embodiment of the present invention is a transmitter that is robust to a distance from a receiver, and estimates a coupling coefficient ( ) in response to receiving the first packet containing the information required for calculating the estimated coupling coefficient ( ) and calculate the marginal quality factor ( ) in response to receiving a second packet containing information necessary for the calculation of the second packet and the calculated estimated coupling coefficient ( ) based on the marginal quality factor ( ) is calculated, and the calculated limit quality factor ( ) may be a device for detecting external substances.

[0144] <Operation of the wireless power receiver>

[0145] A receiver according to one embodiment of the present invention comprises an estimated coupling coefficient ( ) can be transmitted to the transmitter as a first packet containing information necessary for the production of the signal.

[0146] Continuing, a receiver according to one embodiment of the present invention has a limit quality factor ( ) can be transmitted to the transmitter as a second packet containing information necessary for the calculation.

[0147] The contents of the first packet and the second packet described above can be understood in the same way as described above with respect to the operation of the transmitter, and therefore, their description is omitted to avoid excessive duplication.

[0148] Continuing, a receiver according to one embodiment of the present invention may request transmission of a detection result of a foreign substance. Specifically, the detection result of the foreign substance described above may include at least one of information related to the presence of the foreign substance and the kQ slope calculated by the transmitter (i.e., the final kQ slope formula).

[0149] Specifically, according to one embodiment of the present invention, detection of a foreign substance is performed by a transmitter, and a receiver can request the transmitter to transmit the foreign substance detection result. This request can be performed by the receiver sending a request packet to the transmitter. Specifically, the above-described request packet can be a GET packet. This GET packet can have, for example, a structure similar to the packet illustrated in FIG. 10. Referring to FIG. 10, a foreign substance detection result can be requested by transmitting a request packet to the receiver with a specific value included in the parameter field (1000). The specific value included in this parameter can mean a numerical value indicating what content is to be requested through the GET packet. For example, a specific parameter value (specific value) for requesting a foreign substance detection result can be 13.

[0150] Continuing, a transmitter according to one embodiment of the present invention may respond by transmitting a packet containing information about the detection result to the receiver in response to receiving the above-described request packet (GET packet) from the receiver.

[0151] For example, a packet including information about a detection result may be a Mated-Q Result packet, and may have a structure such as a packet as specifically shown in FIG. 11. Referring to FIG. 11, the detection result may be included in a kQ slope result field (1100). Specifically, the kQ slope result may be expressed as a specific value assigned according to each result. For example, the value may be assigned as 0 for not able to compute or not able to compute the kQ slope coefficient, 1 for no foreign material (no FO), 2 for FO detected, and 3 for inconclusive. The above-mentioned specific values ​​may be included in the kQ slope result field (1100) of the packet as shown in FIG. 11 and transmitted to the receiver according to an actual foreign material detection result.

[0152] Wireless Power Receiver

[0153] A receiver according to one embodiment of the present invention comprises an estimated coupling coefficient ( ) transmits the first packet containing the information required for calculating the marginal quality factor ( ) may be a device that transmits a second packet containing information necessary for the production of the detection result of an external substance produced by the transmitter and requests the transmission of the detection result of the external substance produced by the transmitter.

[0154] Accuracy of the wireless power transmission system according to the present invention

[0155] A wireless power transmission system according to one embodiment of the present invention comprises a coil-interface gap ( ) can detect foreign substances with high accuracy even when they are large.

[0156] Referring to Fig. 12, the coil-interface gap ( ) is larger than the conventional one (i.e., 2.0 mm, which is larger than the conventional one 1.2 mm), the accuracy of the conventional foreign substance detection method (the mated-Q and mated-Q-distance methods) and the foreign substance detection method according to an embodiment of the present invention can be compared. Specifically, among the conventional methods, the mated-Q method showed a false positive detection result rate of 85.7%, and among the conventional methods, the mated-Q-distance method showed a false negative detection result rate of 100%, but under the same conditions, the foreign substance detection method according to an embodiment of the present invention (“proposal I” is the result by the linear regression analysis described above, and “proposal II” is the result by the logistic regression analysis described above) did not show any false negative or false positive results (i.e., 0%).

[0157] In addition, the coupling coefficient according to one embodiment of the present invention ( ) and quality factor ( ) can be calculated using values ​​already measured in the existing Qi standard (or Qi2 standard), so they can be directly applied to the existing Qi standard.

[0158] Furthermore, the wireless power transmission system according to one embodiment of the present invention is configured to have a distance from the receiver or a coil-interface gap ( ), so that the distance to the receiver or the coil-interface gap ( ) can detect external substances with high accuracy for all intervals, even if the gap is changed. Accordingly, the wireless power transmission system according to an embodiment of the present invention can be applied to an in-vehicle wireless charging system as described above, and a magnet is applied to detect external substances with high accuracy for all intervals. ) can also be applied to EPP wireless charging systems that can be diverse.

[0159] Although the present invention has been described above with specific details such as specific components and limited examples and drawings, these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and changes based on this description.

[0160] Therefore, the idea of ​​the present invention should not be limited to the embodiments described above, and not only the scope of the patent claims described below but also all scopes equivalent to or equivalently modified from the scope of the patent claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A wireless power transmission method using a wireless power transmitter that is robust to a distance from a wireless power receiver, Step for calculating the estimated coupling coefficient, A step of calculating a marginal quality factor based on the estimated coupling coefficient calculated above, and A step of detecting a foreign substance by referring to the above-determined limit quality factor is included. Method for wireless power transmission.

2. In paragraph 1, In the step of calculating the above limit quality factor, the estimated quality factor is calculated based on the calculated estimated coupling factor, and the limit quality factor is calculated based on the calculated estimated quality factor. Method for wireless power transmission.

3. In paragraph 2, The above estimated quality coefficient is calculated based on the calculated estimated coupling coefficient and the first coefficient indicating the relationship between the estimated quality coefficient and the estimated coupling coefficient. Method for wireless power transfer.

4. In paragraph 3, The above first coefficient is a coefficient corresponding to the fact that both the wireless power transmitter and the wireless power receiver are general devices. Method for wireless power transmission.

5. In paragraph 3, The first coefficient is calculated based on one or more second coefficients and a scaling factor calculated through regression analysis corresponding to at least one of the wireless power transmitter and the wireless power receiver being a reference device. Method for wireless power transmission.

6. In paragraph 1, In the step of calculating the above limit quality factor, the limit quality factor is calculated based on the error margin together with the calculated estimated coupling coefficient. Method for wireless power transmission.

7. In paragraph 1, In the step of detecting the above foreign substance, the measured quality factor is compared with the calculated limit quality factor to detect the foreign substance. Method for wireless power transmission.

8. In paragraph 7, In the step of detecting the above external substance, If the above measurement quality factor is greater than or equal to the above calculated limit quality factor, it is determined that there is no foreign material. If the above measurement quality factor is smaller than the calculated limit quality factor, it is judged that there is a foreign substance. Method for wireless power transmission.

9. A wireless power transmission system using a wireless power transmitter that is robust to a distance from a wireless power receiver, An estimated coupling coefficient calculation unit that calculates an estimated coupling coefficient, A marginal quality factor calculation unit that calculates a marginal quality factor based on the estimated coupling coefficient calculated above, and Includes a foreign substance detection unit that detects foreign substances by referring to the above-determined limit quality factor. Wireless power transfer system.

10. In paragraph 9, The above limit quality factor calculation unit calculates an estimated quality factor based on the calculated estimated coupling factor, and calculates a limit quality factor based on the calculated estimated quality factor. Wireless power transfer system.

11. In paragraph 10, The above estimated quality coefficient is calculated based on the calculated estimated coupling coefficient and the first coefficient indicating the relationship between the estimated quality coefficient and the estimated coupling coefficient. Wireless power transfer system.

12. In paragraph 11, The above first coefficient is a coefficient corresponding to the fact that both the wireless power transmitter and the wireless power receiver are general devices. Wireless power transfer system.

13. In paragraph 11, The first coefficient is calculated based on one or more second coefficients and a scaling factor calculated through regression analysis corresponding to at least one of the wireless power transmitter and the wireless power receiver being a reference device. Wireless power transfer system.

14. In paragraph 9, The above limit quality factor calculation unit calculates the limit quality factor based on the error margin together with the calculated estimated coupling coefficient. Wireless power transfer system.

15. In paragraph 9, The above foreign substance detection unit detects foreign substances by comparing the measured quality factor with the calculated limit quality factor. Wireless power transfer system.

16. In paragraph 15, The above external material detection unit, If the above measurement quality factor is greater than or equal to the above calculated limit quality factor, it is determined that there is no foreign material. If the above measurement quality factor is smaller than the calculated limit quality factor, it is judged that there is a foreign substance. Wireless power transfer system.

17. A method for transmitting wireless power using a wireless power transmitter that is robust to a distance from a wireless power receiver, A step of calculating an estimated coupling coefficient in response to the wireless power transmitter receiving a first packet containing information necessary for calculating an estimated coupling coefficient from a wireless power receiver, A step of calculating a marginal quality factor based on the second packet and the calculated estimated coupling factor in response to receiving a second packet containing information necessary for calculating a marginal quality factor from a wireless power receiver, and A step of detecting a foreign substance by referring to the above-determined limit quality factor is included. Method for wireless power transmission.

18. In paragraph 17, In the step of calculating the estimated coupling coefficient, the estimated coupling coefficient is calculated based on the eigen coefficient and the voltage measurement value measured by the wireless power transmitter together with the first packet. Method for wireless power transmission.

19. In paragraph 17, In the step of calculating the above limit quality factor, the limit quality factor is calculated based on the first coefficient indicating the relationship between the estimated combining coefficient and the estimated quality factor together with the second packet. Method for wireless power transmission.

20. In paragraph 17, In the step of calculating the above limit quality factor, the limit quality factor is further calculated based on the error margin calculated based on the standard deviation of the second packet and the wireless power transmitter. Method for wireless power transmission.

21. In paragraph 17, In the step of detecting the above foreign substance, the wireless power transmitter calculates a measurement quality factor and compares the calculated measurement quality factor with the calculated limit quality factor to detect the foreign substance. Method for wireless power transmission.

22. In paragraph 21, The calculation of the above measurement quality factor is performed by the wireless power transmitter measuring the quality factor corresponding to the positioning of the wireless power receiver on the interface surface of the wireless power transmitter. Method for wireless power transmission.

23. In paragraph 21, In the step of detecting the above external substance, The wireless power transmitter determines that there is no foreign matter in response to the above measurement quality factor being greater than or equal to the above calculated limit quality factor, The wireless power transmitter determines that there is a foreign substance in response to the above measurement quality factor being smaller than the above calculated limit quality factor. Method for wireless power transfer.

24. As a wireless power transmitter that is robust to distance from a wireless power receiver, In response to receiving a first packet containing information necessary for calculating an estimated coupling coefficient from a wireless power receiver, an estimated coupling coefficient is calculated, and in response to receiving a second packet containing information necessary for calculating a marginal quality factor from a wireless power receiver, a marginal quality factor is calculated based on the second packet and the calculated estimated coupling coefficient, and a foreign material is detected with reference to the calculated marginal quality factor. Wireless power transmitter.

25. A method for transmitting wireless power using a wireless power transmitter that is robust to a distance from a wireless power receiver, A step in which a wireless power receiver transmits a first packet containing information necessary for calculating an estimated coupling coefficient to a wireless power transmitter; A step of transmitting a second packet containing information necessary for calculating a limit quality factor to a wireless power transmitter by the wireless power receiver, and A step of requesting transmission of the detection result of an external substance produced by the wireless power transmitter. Method for wireless power transfer.

26. In paragraph 25, The detection result of the above external substance includes the presence or absence of the external substance. Method for wireless power transfer.

27. As a wireless power receiver, A first packet containing information necessary for calculating an estimated coupling coefficient is transmitted to a wireless power transmitter, a second packet containing information necessary for calculating a marginal quality factor is transmitted, and a request is made for transmitting the detection results of external substances calculated by the wireless power transmitter. Wireless power receiver.

Images