KR20230074968A - Wireless power transfer system including relay coil and mitigating frequency splitting phenomena using transmitter matching capacitor and method of operating the same - Google Patents

Abstract

A wireless power transmission system of the present invention may comprise: a transmitter; a receiver; and a control unit controlling the operations of the transmitter and the receiver. The transmitter may comprise: a source coil having a transmission voltage applied thereto and having a transmission capacitance; and a relay coil electrically separated from the source coil and having a relay capacitance. The relay coil can increase the wireless power transmission distance between the transmitter and the receiver. In addition, the wireless power transmission system of the present invention may alleviate a frequency division phenomenon which occurs in the wireless power transmission system by using a transmitter-matching capacitor. According to the present invention, the wireless power transmission system may increase wireless power transmission efficiency by improving the positional freedom of wireless power transmission and reception by using the relay coil and alleviating the frequency division phenomenon by using the transmitter matching capacitor.

Description

A wireless power transmission system including a relay coil and mitigating the frequency division phenomenon using a transmitter matching capacitor and an operating method thereof

The present invention relates to a wireless power transmission system and an operating method thereof, and more particularly, to improve the positional freedom of wireless charging using a relay coil, and to a frequency division phenomenon occurring in a wireless power transmission system using a transmitter matching capacitor. It relates to a wireless power transmission system and method of operating the same that improve wireless power transmission efficiency by mitigating.

Recently, wireless power transfer (WPT) technology has been developed and commercialized in various fields such as portable electronic devices, medical devices, electric vehicles, and robots due to increased convenience and stability due to a simplified charging structure.

In particular, in electric vehicles such as automated guided vehicles (AGVs) used in the plant, automobile, and train industries, research on wireless power transmission technology that delivers a large output of several kW to several tens of kW with high power transmission efficiency is being conducted. It's going on.

In the existing wireless power transmission system, charging is performed only when the location of the receiver is placed in the correct position of the charging pad. there was.

Therefore, in order to increase the wireless power transmission efficiency of the magnetic resonance wireless power transmission system, it is necessary to increase the spatial range in which wireless charging is possible so that wireless power transmission or wireless charging is possible even when the position of the receiver is away from the center by a certain distance.

In addition, in order to increase the wireless power transmission efficiency of the magnetic resonance wireless power transmission system, the coupling coefficient between the coil of the transmitter (Tx) and the coil of the receiver (Rx) must be increased by increasing the size of the coil or reducing the air gap.

In a wireless power transmission system using magnetic coupling, the efficiency of the system improves as the coupling coefficient between the coil of the transmitter and the coil of the receiver increases.

However, if the coupling coefficient is increased, a frequency division phenomenon in which output power is greatly reduced may occur between the coil of the transmitter and the coil of the receiver.

That is, as the coupling coefficient increases, the coil of the transmitter and the coil of the receiver are coupled, and thus a frequency division phenomenon in which the magnitude of transmitted power is rapidly reduced at an operating frequency may occur. This frequency division phenomenon has several adverse effects on system operation.

The wireless power transmission system according to the prior art is designed so that the frequency division does not occur when designing the coil of the transmitter and the coil of the receiver, but the prior art has limitations in improving system efficiency and restricts coil design. do.

That is, research on eliminating the frequency division phenomenon in the prior art has disadvantages of reducing the efficiency of wireless power transmission and reducing the degree of freedom in coil design because the coil structure is designed to reduce the coupling coefficient value.

Therefore, in the wireless power transmission system, the positional freedom of wireless power transmission and reception is improved for efficiency of wireless message transmission, and the operating state of the wireless power transmission system is determined through current sensing in the transmission unit to mitigate the frequency division phenomenon, thereby operating in case of abnormal operation. A technology capable of frequency tuning is required.

US Patent No. 10637,292, "CONTROLLING WIRELESS POWER TRANSFER SYSTEMS" Korean Patent Publication No. 2020-0058808, "Wireless Power Transmitter" Korean Patent Publication No. 2020-0046313, "Wireless transmission coil and wireless power transmitter including the same" Korean Patent Registration No. 1680997, "Wireless power transmission device and method"

An object of the present invention is to provide a wireless power transmission system and method of operating the same that increase the efficiency of wireless power transmission by improving the degree of freedom of the position of wireless power transmission and reception.

In addition, an object of the present invention is to provide a wireless power transmission system and method of operating the same that mitigate the frequency division phenomenon by using a transmitter matching capacitor.

An object of the present invention is to alleviate the frequency division phenomenon of a wireless power transmission system by changing only the transmission capacitor value designed in the wireless power transmission system without additional circuit design.

An object of the present invention is to achieve a high wireless power transmission rate while securing stability of a wireless power transmission system even when a coupling coefficient is increased to improve the efficiency of wireless power transmission during wireless power transmission.

The present invention is a wireless power transmission system using a formula for determining a range of transmission capacitor values for mitigating the frequency division phenomenon based on the analysis after analyzing the system in a circuit manner to mitigate the frequency division phenomenon, and a method of operating the same is intended to provide

In order to achieve one object of the present invention, a wireless power transmission system according to embodiments of the present invention may include a transmission unit, a reception unit, and a control unit that controls operations of the transmission unit and the transmission unit. The transmission unit may include a source coil to which a transmission voltage is applied and having a transmission capacitance, and a relay coil electrically separated from the source coil and having a relay capacitance. The relay coil may increase a wireless power transmission distance between the transmitter and the receiver.

In one embodiment, the center of the source coil coincides with the center of the relay coil, the outer diameter of the relay coil is larger than the outer diameter of the source coil, the relay coil surrounds the source coil, and the outer diameter of the source coil is 42 mm to 48 mm, and the outer diameter of the relay coil may be 54 mm to 60 mm.

In one embodiment, the distance between the center of the source coil and the center of the relay coil is 8 mm to 12 mm, the outer diameter of the relay coil is the same as the outer diameter of the source coil, and the relay coil is the source coil and the receiving part. It is disposed between the receiving coils, and the outer diameter of the source coil may be 42 mm to 48 mm.

In one embodiment, the relay coil includes a first relay coil and a second relay coil, the center of the first relay coil is spaced apart from the center of the source coil by 8 mm to 12 mm in a first direction, and the second relay coil The center of the relay coil is spaced apart from the center of the source coil by 8 mm to 12 mm in a second direction opposite to the first direction, and the outer diameters of the first relay coil and the second relay coil are outer diameters of the source coil. , and the outer diameter of the source coil may be 42 mm to 48 mm.

In one embodiment, the control unit extracts electrical characteristics of the transmission unit and the reception unit, calculates a frequency value at which a differential reactance value of an input impedance converges to 0 using the extracted electrical characteristics, and calculates the calculated frequency value A transmit capacitor value having a reactance value of the input impedance greater than 0 may be calculated using , and a preset transmit capacitor value of the transmit unit may be changed to the calculated transmit capacitor value.

In one embodiment, the control unit uses the following [Equation 6] as an equation for calculating the reactance value of the input impedance, substitutes the extracted electrical characteristic into [Equation 6] and differentiates to obtain the differential reactance The frequency value at which the value converges to 0 can be calculated.

[Equation 6]

In one embodiment, the control unit uses the following [Equation 6] as an equation for calculating the reactance value of the input impedance, substitutes the calculated frequency value into ω in the following [Equation 6], and C With ₁ as an unknown, the range of C ₁ in which X is greater than or equal to 0 can be determined.

[Equation 6]

In one embodiment, the control unit may calculate the range of the transmit capacitor value to be 152.57 kF or more.

In order to achieve another object of the present invention, a method of operating a wireless power transmission system according to embodiments of the present invention includes extracting electrical characteristics of a transmitter and a receiver, differential reactance of input impedance using the extracted electrical characteristics Calculating a frequency value at which the value converges to 0, calculating a transmit capacitor value having a reactance value of the input impedance greater than 0 using the calculated frequency value, and calculating a transmit capacitor value set in advance of the transmit unit A step of changing the calculated transmit capacitor value may be included.

In one embodiment, the step of calculating the frequency value at which the differential reactance value of the input impedance converges to 0 using the extracted electrical characteristics includes the extracted electrical characteristics in an equation for calculating the reactance value of the input impedance. The method may include calculating a frequency value at which the differential reactance value converges to 0 by substituting and differentiating the differential reactance value.

In one embodiment, the step of substituting the extracted electrical characteristic into an equation for calculating the reactance value of the input impedance and differentiating the calculating a frequency value at which the differential reactance value converges to 0 may include reactance of the input impedance A step of using the following [Equation 6] as an equation for calculating the value may be included.

[Equation 6]

In an embodiment, the extracting of the electrical characteristics of the transmitter and the receiver may include extracting electrical characteristics related to at least one of transmission internal resistance, transmission capacitance, and transmission inductance of the transmission unit, the reception unit Extracting as an electrical characteristic related to at least one of a reception internal resistance, a reception capacitance, a reception inductance, and a load resistance, and the transmission inductance, the reception inductance, and the coupling coefficient ) and extracting electrical characteristics related to mutual inductance.

In an embodiment, electrical characteristics related to the transmit capacitance may correspond to the preset transmit capacitor value.

In one embodiment, the step of calculating the transmit capacitor value having a reactance value of the input impedance greater than 0 using the calculated frequency value includes the extracted electrical value in the equation for calculating the reactance value of the input impedance. The method may include calculating a range of transmission capacitor values in which a reactance value of the input impedance is greater than 0 by substituting the calculated frequency value and electrical characteristics other than the capacitor value of the transmitting unit among the characteristics.

In an embodiment, the reactance value of the input impedance is obtained by substituting the calculated frequency value and the electrical characteristics other than the capacitor value of the transmitting unit among the extracted electrical characteristics into the equation for calculating the reactance value of the input impedance. In the step of calculating the range of the transmission capacitor value having a value greater than 0, the following [Equation 6] is used as an equation for calculating the reactance value of the input impedance, and ω in the following [Equation 6] Substituting the calculated frequency value, making C ₁ an unknown, and determining a range of C ₁ in which X is greater than or equal to 0.

[Equation 6]

In one embodiment, the calculating of the transmit capacitor value having the reactance value of the input impedance greater than 0 using the calculated frequency value includes calculating a range of the transmit capacitor value to be 152.57 kF or more. can do.

The present invention can provide a wireless power transmission system and method of operating the same that increase wireless power transmission efficiency by improving the degree of freedom of wireless power transmission and reception using a relay coil.

The present invention can provide a wireless power transmission system and method of operating the same that mitigate a frequency division phenomenon by using a transmitter matching capacitor.

The present invention can alleviate the frequency division phenomenon of the wireless power transmission system by changing only the transmission capacitor value designed in the wireless power transmission system without additional circuit design.

The present invention can achieve a high wireless power transfer rate while securing the stability of a wireless power transfer system even if a coupling coefficient is increased to improve the efficiency of wireless power transfer during wireless power transfer.

The present invention is a wireless power transmission system using a formula for determining a range of transmission capacitor values for mitigating the frequency division phenomenon based on the analysis after analyzing the system in a circuit manner to mitigate the frequency division phenomenon, and a method of operating the same can provide.

1 is a diagram illustrating an equivalent circuit of a wireless power transmission system according to an embodiment of the present invention.
2A to 2C are diagrams illustrating a frequency division phenomenon of a wireless power transmission system.
3 is a diagram illustrating an operating method of a wireless power transfer system according to an embodiment of the present invention.
4A is a diagram illustrating a block diagram of a wireless power transmission system according to an embodiment of the present invention.
4B is a diagram illustrating a block diagram of a wireless power transfer system according to another embodiment of the present invention.
4c and 4d are diagrams illustrating an example of a structure of a transmitter in the wireless power transmission system of FIG. 4b.
4E and 4F are diagrams illustrating an example of a structure of a transmitter in the wireless power transfer system of FIG. 4B.
4g and 4h are diagrams illustrating an example of a structure of a transmitter in the wireless power transfer system of FIG. 4b.
4i and 4j are graphs comparing wireless power transmission efficiency according to embodiments in the case of FIGS. 4c to 4h.
5A and 5B are diagrams illustrating results of capacitor matching in a transmitter of a wireless power transmission system according to an embodiment of the present invention.
6A and 6B are diagrams illustrating matching results of capacitor values of a transmitter in a wireless power transfer system according to an embodiment of the present invention.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification are only illustrated for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention These may be embodied in various forms and are not limited to the embodiments described herein.

Embodiments according to the concept of the present invention can apply various changes and can have various forms, so the embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosures, and includes modifications, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component, for example, without departing from the scope of rights according to the concept of the present invention, a first component may be named a second component, Similarly, the second component may also be referred to as the first component.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle. Expressions describing the relationship between components, such as "between" and "directly between" or "directly adjacent to" should be interpreted similarly.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, but one or more other features or numbers, It should be understood that the presence or addition of steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this specification, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these examples. Like reference numerals in each figure indicate like elements.

1 is a diagram illustrating an equivalent circuit of a wireless power transmission system according to an embodiment of the present invention.

Referring to FIG. 1 , an equivalent circuit 100 of a wireless power transmission system may include a transmitter 110 and a receiver 120.

The transmitter 110 may include a transmit coil, and the receiver 120 may include a receive coil.

According to an embodiment of the present invention, the transmitter 110 transmits voltage (V ₁ ), transmit current (I ₁ ), transmit capacitance (C ₁ ), transmit resistance (R ₁ ) and transmit inductance (L ₁ ) according to electrical characteristics can be extracted.

For example, the transmit inductance (L ₁ ) of the transmitter may have a value of 5uH to 7uH. However, this range is only an example of the transmission inductance (L ₁ ) value, and does not limit the value of the transmission inductance (L ₁ ) of the present invention.

In addition, electrical characteristics of the receiving unit 120 may be extracted according to the receiving current (I ₂ ), the receiving capacitance (C ₂ ), the receiving resistance (R ₂ ), the receiving inductance (L ₂ ), and the load resistance (R _L ). .

According to an embodiment of the present invention, mutual inductance between the transmitter 110 and the receiver 120 may be calculated through [Equation 1] below.

[Equation 1]

In [Equation 1], M may represent mutual inductance, k may represent a coupling coefficient, L ₁ may represent the inductance of the transmitter, and L ₂ may represent the inductance of the receiver.

According to an embodiment of the present invention, the input impedance (Z _in ) may be derived as [Equation 2] according to Kirchhoff's circuit laws in the transmission unit 110 and the reception unit 120.

[Equation 2]

In [Equation 2], Z _in may represent the input impedance, R ₁ may represent the internal resistance of the transmitter, R ₂ may represent the internal resistance of the receiver, and R _L may represent the load resistance (inductance resistance), C ₁ may represent the capacitance of the transmitter, C ₂ may represent the capacitance of the receiver, L ₁ may represent the inductance of the transmitter, and L ₂ may represent the inductance of the receiver, ω may represent a frequency related to each frequency, and M may represent mutual inductance.

According to an embodiment of the present invention, the equivalent circuit 100 of the wireless power transmission system includes internal resistance of the transmitter, internal resistance of the receiver, load resistance (inductance resistance), capacitance of the transmitter, capacitance of the receiver, The inductance of the transmitter and the inductance of the receiver, ω, may provide at least one electrical characteristic related to frequency and mutual inductance related to each frequency.

For example, when the capacitance of the transmitter is changed to mitigate the frequency division phenomenon, the capacitor of the transmitter may be changed. In this case, the capacitor used may be a transmitter matching capacitor.

When the input impedance increases at the operating frequency, the output power can be maximum at the operating frequency because the impedance decreases at a frequency close to the operating frequency.

For example, the operating frequency may be referred to as the resonant frequency and may be approximately 60 kHz.

2A to 2C are diagrams illustrating a frequency division phenomenon of a wireless power transmission system.

2a compares and describes the phase and pole frequencies of the input impedance in relation to the frequency division phenomenon of the wireless power transmission system.

Referring to the graph 200 of FIG. 2A , the horizontal axis of the graph 200 may represent the magnitude of frequency, and the vertical axis may represent the phase of the input impedance.

In the graph 200, the phase of the input impedance is 0 at the operating frequency, but is located in the inductive region before the operating frequency and located in the capacitance region after the operating frequency.

In the graph 200, a frequency division phenomenon in which the first pole frequency (f ₁ ) and the second pole frequency (f ₂ ) is larger than 0 or smaller than 0 is divided at the phase value of the input impedance is confirmed.

Here, based on the operating frequency, it can be seen that the first pole frequency f ₁ is located in the inductive region, and the second pole frequency f ₂ is located in the capacitive region.

That is, as the phase value of the input impedance corresponding to the second pole frequency f ₂ is less than 0, a frequency division phenomenon may occur.

Meanwhile, FIG. 2B compares and describes the reactance and pole frequencies of the input impedance in relation to the frequency division phenomenon of the wireless power transmission system.

Referring to the graph 210 of FIG. 2A , the horizontal axis of the graph 210 may represent the magnitude of frequency, and the vertical axis may represent the reactance of the input impedance.

In the graph 210, the reactance of the input impedance is 0 at the operating frequency, but is located in the inductive region before the operating frequency and located in the capacitance region after the operating frequency.

In the graph 200, a frequency division phenomenon in which the first pole frequency (f ₁ ) and the second pole frequency (f ₂ ) are divided greater than 0 or less than 0 in the reactance value of the input impedance is confirmed.

Here, based on the operating frequency, it can be seen that the first pole frequency f ₁ is located in the inductive region, and the second pole frequency f ₂ is located in the capacitive region.

That is, as the reactance value of the input impedance corresponding to the second pole frequency f ₂ is less than 0, a frequency division phenomenon may occur.

Next, FIG. 2C compares and describes the phase change of the input impedance in the wireless power transmission system in which the frequency division phenomenon does not occur and the phase change in the input impedance in the wireless power transmission system in which the frequency division phenomenon occurs.

Referring to the graph 220 of FIG. 2C , a horizontal axis may represent the magnitude of a frequency, and a vertical axis may represent the phase of an input impedance.

The leader line 221 may indicate a phase change of input impedance in a wireless power transmission system in which the frequency division phenomenon does not occur, and the leader line 222 may indicate a phase change of input impedance in the wireless power transmission system.

The switching frequency of the inverter should be selected higher than the operating frequency for zero voltage switching and placed in the zero or inductive region of the input impedance.

If the inverter's switching frequency operates in the capacitive region where the phase of the input impedance is less than zero, switching losses occur and the device can be damaged.

In frequency division, it is difficult to select the switching frequency because the phase falls into the capacitive region after the operating frequency.

Therefore, in order to reduce the switching frequency selection sensitivity of the inverter and ensure stable operation of the system, the design of the wireless power transmission system is required so that the phase of the input impedance is in the inductive region even after the operating frequency.

3 is a diagram illustrating an operating method of a wireless power transfer system according to an embodiment of the present invention.

3 illustrates an embodiment in which a method of operating a wireless power transmission system for mitigating the frequency division phenomenon using a transmitter matching capacitor according to an embodiment of the present invention alleviates the frequency division phenomenon by changing only the transmission capacitor value without additional circuit design. Explain.

Specifically, in the operating method of the wireless power transmission system according to an embodiment of the present invention, the frequency of the wireless power transmission system is calculated by using an equation to calculate the matching capacitor value of the transmitter, and changing the capacitor value of the transmitter to the matching capacitor value. alleviate splitting.

In step 301, the operating method of the wireless power transmission system according to an embodiment of the present invention extracts electrical characteristics of a transmitter and a receiver.

That is, the operating method of the wireless power transmission system according to an embodiment of the present invention relates to electrical characteristics related to at least one of transmission internal resistance, transmission capacitance, and transmission inductance of a transmission unit, reception internal resistance of a reception unit, and reception Electrical characteristics related to at least one of capacitance, receiving inductance, and load resistance, and electrical characteristics related to mutual inductance related to transmitting inductance, receiving inductance, and coupling coefficient may be extracted. can

In step 302, the operating method of the wireless power transmission system according to an embodiment of the present invention calculates a frequency value at which the differential reactance value converges to 0 using the electrical characteristics extracted in step 301.

Here, the operating method of the wireless power transmission system derives the following [Equation 3] composed of an imaginary part and a real part in order to calculate a frequency value at which the differential reactance value converges to 0.

[Equation 3]

[Equation 3] is replaced with letters (A, B, C, D, E, F) as shown in parentheses to simplify the expression.

In [Equation 3], Z _in may represent the input impedance, R ₁ may represent the internal resistance of the transmitter, R ₂ may represent the internal resistance of the receiver, and R _L may represent the load resistance ( inductance resistance), C ₁ may represent the capacitance of the transmitter, C ₂ may represent the capacitance of the receiver, L ₁ may represent the inductance of the transmitter, and L ₂ is Inductance of the receiver may be represented, ω may represent frequency, and M may represent mutual inductance.

[Equation 3] may represent the resistance and reactance of the input impedance, the following [Equation 4] in [Equation 3] may represent the phase of the input impedance, and [Equation 5] represents the reactance of the input impedance can indicate

[Equation 4]

[Equation 4] is replaced with letters (A, B, C, D, E, F) as shown in parentheses to simplify the expression.

In [Equation 4], phase of Z _in may represent the phase of the input impedance, R ₁ may represent the internal resistance of the transmitter, R ₂ may represent the internal resistance of the receiver, and R _L may represent the load resistance (inductance resistance), C ₁ may represent the capacitance of the transmitter, C ₂ may represent the capacitance of the receiver, L ₁ may represent the inductance of the transmitter, , L ₂ may represent inductance of the receiver, ω may represent frequency, and M may represent mutual inductance.

[Equation 5]

[Equation 5] is replaced with letters (A, B, C, D, E, F) as shown in parentheses to simplify the expression.

In [Equation 5], X may represent the reactance of the input impedance, R ₁ may represent the internal resistance of the transmitter, R ₂ may represent the internal resistance of the receiver, and R _L may represent the load resistance (inductance resistance), C ₁ may represent the capacitance of the transmitter, C ₂ may represent the capacitance of the receiver, L ₁ may represent the inductance of the transmitter, and L ₂ May represent inductance of the receiver, ω may represent frequency, and M may represent mutual inductance.

When the simplified letters (A, B, C, D, E, F) in [Equation 5] are applied to the equation, the following [Equation 6] can be derived.

[Equation 6]

In [Equation 6], X may represent the reactance of the input impedance, R ₁ may represent the internal resistance of the transmitter, R ₂ may represent the internal resistance of the receiver, and R _L may represent the load resistance (inductance resistance), C ₁ may represent the capacitance of the transmitter, C ₂ may represent the capacitance of the receiver, L ₁ may represent the inductance of the transmitter, and L ₂ may represent the inductance of the receiver, ω may represent a frequency related to each frequency, and M may represent mutual inductance.

More specifically, the operating method of the wireless power transmission system calculates the frequency value at which the differential reactance value converges to 0 by substituting the extracted electrical characteristics into the equation for calculating the reactance value of the input impedance and differentiating the input impedance. [Equation 6] described above is used as an equation for calculating the reactance value of the impedance.

That is, the present invention uses [Equation 6] to obtain a range of transmission capacitor values for mitigating the frequency division phenomenon based on the analysis after analyzing the system in a circuit manner to mitigate the frequency division phenomenon.

Therefore, the present invention can alleviate the frequency division phenomenon by changing only the transmit capacitor value designed in the existing high-efficiency resonant wireless power transmission system without additional circuit design.

In addition, according to the present invention, even when a coupling coefficient is increased for high efficiency in wireless power transmission, the system can stably and transmit high power.

In step 303, the operating method of the wireless power transmission system according to an embodiment of the present invention calculates a transmit capacitor value having a reactance value greater than 0 using the frequency value calculated in step 302.

That is, in the operating method of the wireless power transmission system, the reactance value of the input impedance is obtained by substituting the electrical characteristics other than the capacitor value of the transmitter and the calculated frequency value among the electrical characteristics extracted in the equation for calculating the reactance value of the input impedance. Calculate the range of transmit capacitor values with values greater than zero.

Specifically, the operating method of the wireless power transmission system uses the above-described [Equation 6] as an equation for calculating the reactance value of the input impedance, substitutes the calculated frequency value into ω in [Equation 6], , C ₁ is unknown, the range of C ₁ in which X is greater than 0 is determined, and the smallest value in the range of C ₁ is determined as the transmit capacitor value for high efficiency of the system among the range of C ₁ .

For example, the operating method of the wireless power transmission system may calculate a transmission capacitor value range of 152.57 kF or more.

In step 304 of the operating method of the wireless power transmission system according to an embodiment of the present invention, the preset transmission capacitor value is replaced with the transmission capacitor value calculated in step 303.

That is, the operating method of the wireless power transmission system uses a transmitter matching capacitor corresponding to the transmit capacitor value calculated in step 303.

Therefore, the present invention can alleviate the frequency division phenomenon of the wireless power transmission system by changing only the transmission capacitor value designed in the wireless power transmission system without additional circuit design.

In addition, the present invention can achieve a high wireless power transmission rate while securing stability of a wireless power transmission system even when a coupling coefficient is increased to improve the efficiency of wireless power transmission in wireless power transmission.

4A is a diagram illustrating a block diagram of a wireless power transmission system according to an embodiment of the present invention.

4A illustrates components of a wireless power transfer system according to an embodiment of the present invention.

Referring to FIG. 4A , a wireless power transfer system 400 according to an embodiment of the present invention may include a transmitter 410, a receiver 420, and a controller 430.

The wireless power transmission system 400 according to an embodiment of the present invention changes only the transmission capacitor value without additional circuit design to mitigate the frequency division phenomenon by using the above-mentioned capacitor value corresponding to the capacitor value of the matching capacitor of the transmitter [Equation 6], and the frequency division phenomenon in the wireless power transmission system 400 can be mitigated by selectively using the transmitter matching capacitor corresponding to the calculated capacitor value.

For example, the transmitter 410 may transmit wireless power to the receiver 420 .

For example, the transmitter 410 may include a transmit coil, and the receiver 420 may include a receive coil.

4B is a diagram illustrating a block diagram of a wireless power transfer system according to another embodiment of the present invention.

4B illustrates a case in which the transmitter 410 of the wireless power transfer system includes a source coil 411 and a relay coil 412.

Referring to FIG. 4B , the transmitter 410 may include a source coil 411 and a relay coil 412 . The source coil 411 may have a transmit voltage and transmit capacitance. The relay coil 412 may be electrically separated from the source coil and may have a relay capacitance.

In the existing wireless power transmission system, charging is performed only when the receiver 420 is placed in the correct position of the charging pad. There is an impossible problem.

Therefore, in order to increase the wireless power transmission efficiency of the wireless power transmission system, it is necessary to increase the spatial range in which wireless charging is possible so that wireless power transmission or wireless charging is possible even when the location of the receiver 420 is away from the center by a certain distance. .

By including the relay coil 412 in the transmitter 410, a transmission distance of wireless power transmitted to the receiver 420 can be increased. That is, the relay coil 412 may increase a wireless power transmission distance between the transmitter 410 and the receiver 420 .

4C and 4D are diagrams illustrating an example of a structure of a transmitter 410a in the wireless power transfer system of FIG. 4B.

Specifically, FIG. 4C is a plan view of the transmitter 410a viewed from above in a horizontal direction, and FIG. 4D is a cross-sectional view of the transmitter 410a viewed from the side in a vertical direction.

Referring to FIGS. 4C and 4D , the source coil 411 may be surrounded by the relay coil 412 . The relay coil 412 may be disposed on the same layer as the source coil 411 and may be disposed in a form surrounding the source coil 411 .

For example, the center of the source coil 411 and the center of the relay coil 412 may coincide, and the outer diameter of the relay coil 412 may be larger than the outer diameter of the source coil 411 .

In one embodiment, the outer diameter of the source coil 411 may be 42 mm to 48 mm, and the outer diameter of the relay coil 412 may be 54 mm to 60 mm.

In this way, according to the structure of the transmission unit 410a in which the relay coil 412 is arranged in a form surrounding the source coil 411, the transmission unit 410a and the transmission unit 410a are more likely than when the transmission unit 410 is composed of a single source coil. A wireless power transmission distance between the receivers 420 may increase.

Therefore, since wireless power transmission or wireless charging is possible even when the location of the receiver is out of the center by a predetermined distance, the wireless power transmission efficiency of the wireless power transmission system can be increased in all directions.

4E and 4F are diagrams illustrating an example of a structure of a transmitter 410b in the wireless power transmission system of FIG. 4B.

Specifically, FIG. 4E is a plan view of the transmitter 410b viewed from above in a horizontal direction, and FIG. 4F is a cross-sectional view of the transmitter 410b viewed from the side in a vertical direction.

Referring to FIGS. 4E and 4F , the relay coil 412 may be disposed between the source coil 411 and the receiving coil of the receiver 420 . For example, the relay coil 412 may be disposed above the source coil 411 .

The relay coil 412 may be displaced from the source coil 411 by a predetermined distance. For example, the distance between the center of the source coil 411 and the center of the relay coil 412 may be 8 mm to 12 mm.

The outer diameter of the relay coil 412 may be the same as that of the source coil 411 . For example, the outer diameter of the source coil 411 may be 42 mm to 48 mm, and the outer diameter of the relay coil 412 may be 42 mm to 48 mm.

In this way, the center of the relay coil 412 and the center of the source coil 411 are separated by a certain distance, and the relay coil 412 and the source coil 411 are arranged in the same size in the structure of the transmitter 410b. Accordingly, a wireless power transmission distance between the transmitter 410b and the receiver 420 may be increased compared to a case in which the transmitter 410 includes a single source coil.

Therefore, since wireless power transmission or wireless charging is possible even when the location of the receiver 420 is away from the center by a certain distance, the wireless power transmission efficiency of the wireless power transmission system can be increased in one direction.

4G and 4H are diagrams illustrating an example of a structure of a transmitter 410c in the wireless power transfer system of FIG. 4B.

Specifically, FIG. 4g is a plan view of the transmitter 410c viewed from above in a horizontal direction, and FIG. 4h is a cross-sectional view of the transmitter 410c viewed from the side in a vertical direction.

Referring to FIGS. 4G and 4H , the relay coil 412 may include a first relay coil and a second relay coil.

The first relay coil and the second relay coil may be disposed between the source coil 411 and the receiving coil of the receiver 420 . For example, the first relay coil may be disposed above the source coil 411 . The second relay coil may be disposed above the first relay coil.

The center of the first relay coil is separated from the center of the source coil 411 by a predetermined distance in a first direction, and the center of the second relay coil is opposite to the center of the source coil 411 in the first direction. It may be separated by a predetermined distance in the second direction.

For example, the center of the first relay coil may be 8 mm to 12 mm apart from the center of the source coil 411 in the first direction. The center of the second relay coil may be spaced apart from the center of the source coil 411 by 8 mm to 12 mm in the second direction.

The outer diameters of the first relay coil and the second relay coil may be the same as those of the source coil 411 . For example, the outer diameter of the source coil 411 may be 42 mm to 48 mm, and the outer diameters of the first relay coil and the outer diameter of the second relay coil may be 42 mm to 48 mm.

In this way, the first relay coil and the second relay coil are disposed apart from each other in opposite horizontal directions based on the center of the source coil 411, and the size of the first relay coil and the second relay coil is the same as the source coil 411 According to the structure of the transmitter 410c disposed in the same size as the size of the transmitter 410c, the wireless power transmission distance between the transmitter 410c and the receiver 420 may be increased compared to the case where the transmitter is composed of a single source coil.

Therefore, since wireless power transmission or wireless charging is possible even when the location of the receiver 420 is away from the center by a certain distance, the wireless power transmission efficiency of the wireless power transmission system can be increased in the first and second directions.

4i and 4j are graphs comparing wireless power transmission efficiency according to embodiments in the case of FIGS. 4c to 4h.

Specifically, FIG. 4I is a graph showing a change in wireless power transmission efficiency according to a separation distance between a receiver and a transmitter according to a coil configuration of each transmitter 410a, 410b, and 410c at an operating frequency of 110 kHz. 4J is a graph showing a change in wireless power transmission efficiency according to a distance between a receiver and a transmitter according to a coil configuration of each of the transmitters 410a, 410b, and 410c at an operating frequency of 140 kHz.

Referring to FIG. 4I , at an operating frequency of 110 kHz, when the transmission unit is composed of a single source coil, wireless power transmission efficiency may rapidly decrease in a section where the separation distance between the reception unit and the transmission unit is 10 mm or more.

In addition, when the transmitter is composed of a single source coil, the wireless power transmission efficiency of the transmitter may be significantly reduced to about 70% at a separation distance of 15 mm.

On the other hand, in the case of the structure of the transmitter 410a in which the relay coil surrounds the source coil, the wireless power transfer efficiency is about 89% when the distance between the receiver and the transmitter is 10 mm, and when the distance is 15 mm, the wireless Power transfer efficiency may be 80% or more.

In addition, in the case of the structure of the transmitter 410b in which the center of the relay coil and the center of the source coil are separated by a predetermined distance and the relay coil and the source coil are arranged in the same size, when the distance between the receiver and the transmitter is 10 mm, wireless The power transmission efficiency is about 91%, and the wireless power transmission efficiency can be maintained as high as about 86% when the separation distance is 15 mm.

In addition, the first relay coil and the second relay coil are arranged to be spaced apart in opposite horizontal directions based on the center of the source coil, and the size of the first relay coil and the second relay coil is the same as the size of the source coil. In the case of the structure of the transmitter 410c, the wireless power transmission efficiency may be about 89% when the separation distance between the reception unit and the transmission unit is 10 mm, and the wireless power transmission efficiency may be 80% or more when the separation distance is 15 mm.

That is, when the transmission units 410a, 410b, and 410c include relay coils, the transmission distance of wireless power between the transmission unit and the reception unit is increased at an operating frequency of 110 kHz, and the transmission unit has a single source coil. Power transfer efficiency can be increased.

Referring to FIG. 4J , at an operating frequency of 140 kHz, when the transmission unit is composed of a single source coil, wireless power transmission efficiency may rapidly decrease in a section where the separation distance between the reception unit and the transmission unit is 10 mm or more.

In addition, when the transmitter is composed of a single source coil, the wireless power transmission efficiency of the transmitter may be significantly reduced to about 73% at a separation distance of about 13 mm. When calculated at the same ratio, it can be expected that the wireless power transmission efficiency of the transmitter decreases to about 64% or less at a separation distance of about 15 mm.

On the other hand, in the case of the structure of the transmitter 410a in which the relay coil is arranged to surround the source coil, the wireless power transfer efficiency is about 86% when the distance between the receiver and the transmitter is 10 mm, and the wireless power transfer efficiency is about 15 mm when the distance is 15 mm. The power transfer efficiency may be about 73%. That is, in this case, the decrease in wireless power transmission efficiency can be minimized compared to the case where the transmission unit is composed of a single source coil.

In addition, in the case of the structure of the transmitter 410b in which the center of the relay coil and the center of the source coil are separated by a predetermined distance and the relay coil and the source coil are arranged in the same size, when the distance between the receiver and the transmitter is 10 mm, wireless The power transmission efficiency is about 92%, and the wireless power transmission efficiency can be maintained as high as about 88% when the separation distance is 15 mm.

In addition, the first relay coil and the second relay coil are arranged to be spaced apart in opposite horizontal directions based on the center of the source coil, and the size of the first relay coil and the second relay coil is the same as the size of the source coil. In the case of the structure 410c of the transmitter, the wireless power transmission efficiency may be about 87% when the distance between the receiver and the transmitter is 10 mm, and the wireless power transmission efficiency may be 80% or more when the distance is 15 mm.

That is, when the transmission units 410a, 410b, and 410c include relay coils, the transmission distance of wireless power between the transmission unit and the reception unit increases at an operating frequency of 140 kHz, and the transmission unit has a single source coil. Power transfer efficiency can be increased.

According to an embodiment of the present invention, the control unit 430 extracts the electrical characteristics of the transmitter 410 and the receiver 420, and uses the extracted electrical characteristics as a frequency value at which the differential reactance value of the input impedance converges to zero. can be calculated.

In addition, the control unit 430 calculates a transmit capacitor value having a reactance value of the input impedance greater than 0 using the calculated frequency value, and calculates the preset transmit capacitor value of the transmit unit 410 by [Equation 6]. Change to the calculated transmit capacitor value using

That is, the controller 430 calculates the transmission capacitor value of the transmission matching capacitor so that the transmission matching capacitor can be used, and presents the calculated transmission capacitor value.

According to an embodiment of the present invention, the control unit 430 uses [Equation 6] as an equation for calculating the reactance value of the input impedance, substitutes the electrical characteristics extracted in [Equation 6], and differentiates by differentiating. Calculate the frequency value at which the reactance value converges to zero.

에 계산된 주파수 값을 대입하고, C₁을 미지수로 하며, X가 0 이상이 되는 C₁의 범위를 결정할 수 있다.For example, the control unit 430 uses [Equation 6] as an equation for calculating the reactance value of the input impedance, and in [Equation 6]

By substituting the calculated frequency value into C 1 , the range of C ₁ in which X is greater than or equal to 0 can be determined with C ₁ as an unknown.

Accordingly, the control unit 430 may calculate the range of the transmit capacitor value to be 152.57 kF or more.

The range of the value of the transmission capacitor described above can be selectively determined in consideration of efficiency in the range of 152.57 ㎋ or more. That is, the calculated transmission capacitor value may be determined to be 152.57 kF or more.

In other words, the transmission capacitor value may be determined as the minimum value within the range of the transmission capacitor value calculated by considering the efficiency of the wireless power transmission system.

According to an embodiment of the present invention, the control unit 430 uses a transmission unit matching capacitor having a transmission capacitor value provided by providing a range of transmission capacitor values.

According to an embodiment of the present invention, the control unit 430 may extract electrical characteristics related to at least one of transmission internal resistance, transmission capacitance, and transmission inductance of the transmission unit 410 .

In addition, the control unit 430 may extract electrical characteristics related to at least one of the receiving internal resistance, receiving capacitance, receiving inductance, and load resistance of the receiving unit 420 .

In addition, the control unit 430 may extract electrical characteristics related to mutual inductance related to transmission inductance, reception inductance, and coupling coefficient.

Therefore, the present invention is a wireless power transmission system using a formula for determining the range of transmission capacitor values for mitigating the frequency division phenomenon based on the analysis after analyzing the system in a circuit manner to mitigate the frequency division phenomenon, and the wireless power transmission system and the same operation method can be provided.

5A and 5B are diagrams illustrating results of capacitor matching in a transmitter of a wireless power transmission system according to an embodiment of the present invention.

Specifically, FIGS. 5A and 5B illustrate results in which the frequency division phenomenon is mitigated by using a transmitter matching capacitor in a wireless power transmission system.

Referring to the graph 500 of FIG. 5A , the horizontal axis of the graph 500 represents a frequency change, and the vertical axis represents a phase change of the input impedance.

The graph 500 compares the phase change of the input impedance when the transmit capacitor value C1 is 114 kF and 153 kF.

Referring to the graph 500, the case where the transmission capacitor value is 114 ㎋ corresponds to the existing transmission capacitor calculated considering the resonant frequency at which the frequency division phenomenon occurs, and the case where the transmission capacitor value is 153 ㎋ is one of the present invention. Depending on the embodiment, this may correspond to a case where a matching capacitor value of the transmitter is used.

When the transmission capacitor value is 114 ㎋, the phase of the input impedance is lower than zero at one of the frequencies having two poles based on the operating frequency.

On the other hand, when the transmit capacitor value is 153 ㎋, the phases of input impedances of frequencies having two poles are all greater than zero based on the operating frequency.

Therefore, when the transmission capacitor value is 153 kF, switching loss does not occur because it does not operate in the capacitive region where the phase of the input impedance is less than 0.

In other words, when the transmission capacitor value is 153 kF, the phase of the input impedance does not go below 0, so the frequency division phenomenon is alleviated.

Meanwhile, referring to the graph 510 of FIG. 5B , a horizontal axis of the graph 510 represents a frequency change, and a vertical axis represents a reactance change of input impedance.

The graph 510 compares the change in reactance of the input impedance when the transmit capacitor value (C ₁ ) is 114 kF and 153 kF.

Referring to the graph 510, when the transmission capacitor value is 114 ㎋, it may correspond to an existing capacitor where frequency division occurs, and when the transmission capacitor value is 153 ㎋, the transmission unit matching according to an embodiment of the present invention. This may correspond to a case where a capacitor value is used.

When the transmit capacitor value is 114 ㎋, the reactance of the input impedance is lower than 0 at one of the frequencies having two poles based on the operating frequency.

On the other hand, when the transmit capacitor value is 153 ㎋, the reactance of the input impedance is greater than 0 at all frequencies having two poles based on the operating frequency.

Therefore, when the transmission capacitor value is 153 kF, switching loss does not occur because it does not operate in the capacitive region where the reactance of the input impedance is less than 0.

In other words, when the transmit capacitor value is 153 kF, the frequency division phenomenon is alleviated compared to the case where the transmit capacitor value is 114 kF.

6A and 6B are diagrams illustrating matching results of capacitor values of a transmitter in a wireless power transfer system according to an embodiment of the present invention.

Specifically, FIGS. 6A and 6B compare simulation results and actual measurement results according to the transmission unit capacitor value in the wireless power transmission system according to an embodiment of the present invention.

Referring to FIG. 6A, a graph 600 illustrates a case where the capacitor value of the transmitter of the wireless power transmission system is 108 kF, the horizontal axis represents the frequency change, and the vertical axis represents the phase change of the input impedance.

Referring to the graph 600, both the actual measurement result and the simulation result confirm that the frequency division phenomenon occurs when the capacitor value of the transmitter of the wireless power transmission system is 108 kF.

Referring to FIG. 6B, a graph 610 illustrates a case where the capacitor value of the transmitter of the wireless power transmission system is 156 kF, the horizontal axis represents a frequency change, and the vertical axis represents a phase change of input impedance.

Referring to the graph 610, both the actual measurement result and the simulation result confirm that the frequency division phenomenon is alleviated for the case where the capacitor value of the transmission unit of the wireless power transmission system is 185 kF.

For example, if the capacitor value of the transmitter of the wireless power transmission system is 156 ㎋, the simulation result can confirm that the coil-to-coil performance is 90.55%, and the actual measurement result can confirm that the coil-to-coil performance is 92.47%. there is.

The devices described above may be implemented as hardware components, software components, and/or a combination of hardware components and software components. For example, devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. A processing device may run an operating system (OS) and one or more software applications running on the operating system. A processing device may also access, store, manipulate, process, and generate data in response to execution of software. For convenience of understanding, there are cases in which one processing device is used, but those skilled in the art will understand that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that it can include. For example, a processing device may include a plurality of processors or a processor and a controller. Other processing configurations are also possible, such as parallel processors.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program commands recorded on the medium may be specially designed and configured for the embodiment or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. - includes hardware devices specially configured to store and execute program instructions, such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Software may include a computer program, code, instructions, or a combination of one or more of the foregoing, which configures a processing device to operate as desired or processes independently or collectively. The device can be commanded. Software and/or data may be any tangible machine, component, physical device, virtual equipment, computer storage medium or device, intended to be interpreted by or provide instructions or data to a processing device. , or may be permanently or temporarily embodied in a transmitted signal wave. Software may be distributed on networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer readable media.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques may be performed in an order different from the method described, and/or components of the described system, structure, device, circuit, etc. may be combined or combined in a different form than the method described, or other components may be used. Or even if it is replaced or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

400: wireless power transmission system
410: transmitter 411: source coil
412: relay coil 420: receiver
430: control unit

Claims (16)

In the wireless power transmission system for mitigating the frequency division phenomenon using a transmitter matching capacitor,
transmission unit;
receiver; and
Including the transmission unit and a control unit for controlling the operation of the transmission unit,
The sending unit,
a source coil to which a transmission voltage is applied and having a transmission capacitance; and
A relay coil electrically separated from the source coil and having a relay capacitance;
The relay coil,
Characterized in that the wireless power transmission distance between the transmitter and the receiver is increased,
A wireless power transfer system. According to claim 1,
The center of the source coil coincides with the center of the relay coil,
The outer diameter of the relay coil is larger than the outer diameter of the source coil,
The relay coil surrounds the source coil,
The outer diameter of the source coil is 42 mm to 48 mm,
Characterized in that the outer diameter of the relay coil is 54 mm to 60 mm,
wireless power transmission system According to claim 1,
The distance between the center of the source coil and the center of the relay coil is 8 mm to 12 mm,
The outer diameter of the relay coil is the same as the outer diameter of the source coil,
The relay coil is disposed between the source coil and the receiving coil of the receiving unit,
Characterized in that the outer diameter of the source coil is 42 mm to 48 mm,
wireless power transmission system According to claim 1,
The relay coil includes a first relay coil and a second relay coil,
The center of the first relay coil is spaced apart from the center of the source coil by 8 mm to 12 mm in a first direction;
The center of the second relay coil is spaced apart from the center of the source coil by 8 mm to 12 mm in a second direction opposite to the first direction,
The outer diameters of the first relay coil and the second relay coil are the same as those of the source coil,
Characterized in that the outer diameter of the source coil is 42 mm to 48 mm,
wireless power transmission system According to claim 1,
The control unit extracts electrical characteristics of the transmitting unit and the receiving unit, calculates a frequency value at which the differential reactance value of the input impedance converges to 0 using the extracted electrical characteristics, and uses the calculated frequency value to calculate the input impedance value. Calculating a transmit capacitor value having a reactance value greater than 0, and changing the preset transmit capacitor value of the transmit unit to the calculated transmit capacitor value.
A wireless power transfer system. According to claim 5,
The control unit uses the following [Equation 6] as an equation for calculating the reactance value of the input impedance, substitutes the extracted electrical characteristics into the following [Equation 6] and differentiates so that the differential reactance value is 0. Characterized in calculating the converging frequency value
A wireless power transmission system.
[Equation 6]

According to claim 5,
The control unit
[Equation 6] is used as an equation for calculating the reactance value of the input impedance, and the calculated frequency value is substituted for ω in the following [Equation 6], C ₁ is an unknown number, and X is Characterized in determining the range of C ₁ that is greater than or equal to 0
A wireless power transmission system.
[Equation 6]

According to claim 7,
The control unit
Characterized in that the range of the transmission capacitor value is calculated to be 152.57 ㎋ or more
A wireless power transfer system. A method of operating a wireless power transmission system that increases a wireless power transmission distance using a relay coil,
Extracting electrical characteristics of the transmitter and receiver;
calculating a frequency value at which a differential reactance value of an input impedance converges to 0 using the extracted electrical characteristics;
calculating a transmit capacitor value having a reactance value of input impedance greater than 0 using the calculated frequency value; and
And changing the preset transmission capacitor value of the transmission unit to the calculated transmission capacitor value.
A method of operating a wireless power transmission system. According to claim 9,
Calculating the frequency value at which the differential reactance value of the input impedance converges to 0 using the extracted electrical characteristics is
Calculating a frequency value at which the differential reactance value converges to 0 by substituting the extracted electrical characteristic into an equation for calculating a reactance value of the input impedance and differentiating the extracted electrical characteristic.
A method of operating a wireless power transmission system. According to claim 10,
Calculating a frequency value at which the differential reactance value converges to 0 by substituting the extracted electrical characteristics into the equation for calculating the reactance value of the input impedance and differentiating the extracted electrical characteristics,
Characterized in that it comprises the step of using the following [Equation 6] as an equation for calculating the reactance value of the input impedance
A method of operating a wireless power transmission system.
[Equation 6]

According to claim 11,
The step of extracting the electrical characteristics of the transmitter and receiver,
extracting electrical characteristics related to at least one of transmission internal resistance, transmission capacitance, and transmission inductance of the transmission unit;
extracting electrical characteristics related to at least one of a reception internal resistance, a reception capacitance, a reception inductance, and a load resistance of the receiver; and
Extracting electrical characteristics related to mutual inductance related to the transmission inductance, the reception inductance, and a coupling coefficient.
A method of operating a wireless power transmission system. According to claim 12,
Characterized in that the electrical characteristics related to the transmission capacitance correspond to the preset transmission capacitor value
A method of operating a wireless power transmission system. According to claim 9,
Calculating a transmit capacitor value having a reactance value of the input impedance greater than 0 using the calculated frequency value,
By substituting the calculated frequency value and the electrical characteristics other than the capacitor value of the transmitter from among the extracted electrical characteristics in the equation for calculating the reactance value of the input impedance, the reactance value of the input impedance has a value greater than 0. Comprising the step of calculating the range of the transmit capacitor value
A method of operating a wireless power transmission system. According to claim 14,
A value in which the reactance value of the input impedance is greater than 0 is obtained by substituting the calculated frequency value and the electrical characteristics other than the capacitor value of the transmitting unit among the extracted electrical characteristics in the equation for calculating the reactance value of the input impedance. Calculating the range of values of the transmit capacitor having
[Equation 6] is used as an equation for calculating the reactance value of the input impedance, the calculated frequency value is substituted for ω in [Equation 6], C ₁ is an unknown, and X is 0. Characterized in that it comprises the step of determining the range of C ₁ that is greater than
A method of operating a wireless power transmission system.
[Equation 6]

According to claim 14,
Calculating a transmit capacitor value having a reactance value of the input impedance greater than 0 using the calculated frequency value,
Comprising the step of calculating the range of the transmission capacitor value to be 152.57 ㎋ or more
A method of operating a wireless power transmission system.

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