KR20220161906A - Wireless charging apparatus with dynamic coil compensation capability and wireless charging method using thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for wirelessly charging a battery. To solve problems of wireless charging devices and methods of conventional technology, which have a limitation of decreasing efficiency of wireless charging efficiency due to application of a fixed coil compensation method for a predetermined case when a spacing or degree of alignment between a power transmitting coil and a power receiving coil or the shape of the power receiving coil changes, a wireless charging apparatus with a dynamic coil compensation function and a wireless charging method using the same are configured to measure a received voltage, a received current, a transmitted voltage, and a transmitted current and calculate a received power and a transmitted power to calculate and continuously monitor a charging efficiency so that each compensation capacitor is set to a capacitance value of a power receiving coil compensation capacitor and a transmission coil compensation capacitor, which have a maximum charging efficiency when the charging efficiency decreases, thereby maintaining optimal wireless charging efficiency at all times by controlling the compensation capacitor for resonating the power transmitting coil and the power receiving coil dynamically according to a situation. The wireless charging apparatus with a dynamic coil compensation function comprises a power transmitting unit and a power receiving unit.

Description

Wireless charging apparatus with dynamic coil compensation capability and wireless charging method using the same

The present invention relates to an apparatus and method for wireless charging of a battery, and more particularly, in order to maximize wireless charging efficiency in wireless charging of a battery, a capacitor is used so that a transmission coil and a power reception coil resonate at a magnetic field alternating frequency. Dynamic compensation is required, but since the fixed coil compensation method is applied only when the structure of the transmission coil and the reception coil is determined or the distance between the transmission coil and the reception coil is determined, the distance or alignment between the transmission coil and the reception coil is not In order to solve the problem of wireless charging devices and methods of the prior art, which have limitations in that the wireless charging efficiency is reduced because coil compensation is not properly performed when the shape of the power receiving coil changes or the shape of the power receiving coil changes, the alignment of the power transmitting coil and the power receiving coil A wireless charging device having a dynamic coil compensation function configured to automatically optimize wireless charging efficiency by automatically matching impedance according to circumstances when power is transmitted from a single power transmission coil to multiple power receiving coils, and a wireless charging device having the same It is about the wireless charging method used.

In addition, the present invention, as described above, when the distance or alignment between the power transmission coil and the power reception coil changes or the shape of the power reception coil changes, coil compensation is not properly performed, resulting in a decrease in wireless charging efficiency. In order to solve the problems of wireless charging devices and methods of technology, the received power is calculated by measuring the received voltage and received current, the transmitted power is calculated by measuring the transmitted voltage and transmitted current, and the received power is divided by the transmitted power to charge. By calculating the efficiency and continuously monitoring the charging efficiency, when the charging efficiency decreases, each compensation capacitor is configured to set the capacitance value of the receiving coil compensation capacitor and the transmission coil compensation capacitor where the charging efficiency is maximized, A wireless charging device having a dynamic coil compensation function configured to always maintain optimal wireless charging efficiency by controlling a compensation capacitor for dynamically resonating a power transmission coil and a power receiving coil according to the present invention and a wireless charging method using the same.

Recently, with the development of information and communication technology, for example, the demand for portable personal information and communication devices such as smart phones, tablet PCs, or laptops is increasing, and along with this, the demand for eco-friendly technologies is increasing The supply and demand for electric vehicles is increasing.

In addition, as the demand for information communication devices and electric vehicles increases as described above, the demand for batteries provided in various information communication devices or electric vehicles is rapidly increasing, and in addition, to improve the performance and efficiency of such batteries The demand for technology development for

In addition, in recent years, wireless charging technology has been developed to solve the disadvantages of existing charging devices that had the inconvenience of having to connect a charging line to charge the battery, and its application range is gradually expanding. Demand for technology development to improve the performance and efficiency of these wireless charging devices is also increasing.

Here, as an example of the prior art related to an apparatus and method for improving the performance and efficiency of wireless charging as described above, first, for example, as presented in Korean Patent Publication No. 10-2021-0061030, "wireless There is a charging pad, a wireless charging device, and an electric vehicle including the same.

More specifically, the above Korean Patent Publication No. 10-2021-0061030 discloses a coil including a conductive wire; a shield unit disposed on the coil; a first magnetic material disposed between the coil and the shield unit; and a second magnetic material disposed on one surface of the shield unit facing the first magnetic material, so that charging efficiency and heat dissipation characteristics can be improved by having two kinds of magnetic materials. , a wireless charging device, and an electric vehicle including the same.

In addition, another example of the prior art related to an apparatus and method for improving the performance and efficiency of wireless charging as described above is, for example, a "wireless charging module" as presented in Korean Patent Registration No. 10-1792134. there is

More specifically, the above Korean Patent Registration No. 10-1792134 discloses a first magnetic sheet, a second magnetic sheet, a wireless charging antenna unit for receiving wireless power from a wireless charging transmitter, and an NFC antenna for short-range communication. A wireless charging module comprising a unit, wherein the second magnetic sheet includes an opening, an inner surface of the opening is disposed to surround an outer surface of the first magnetic sheet, and a wireless charging antenna unit is disposed on the first magnetic sheet, An NFC antenna unit is disposed on the second magnetic sheet, an adhesive material is disposed between the wireless charging antenna unit and the first magnetic sheet and between the NFC antenna unit and the second magnetic sheet, and the NFC antenna unit and the wireless charging antenna unit are spaced apart from each other The outer surface of the first magnetic sheet and the inner surface of the second magnetic sheet are disposed to face each other, the first magnetic sheet and the second magnetic sheet have different permeability and area, and the wireless charging antenna unit and the NFC antenna An integral composite magnetic sheet configured to maximize wireless charging efficiency while strengthening the communication distance by simultaneously supplementing the NFC antenna function and the wireless charging antenna function, further including a third antenna unit disposed apart from the unit, and a configuration including the same It relates to a wireless charging module that becomes.

As described above, various technical details have been proposed with respect to devices and methods for improving the performance and efficiency of wireless charging, but the contents of the prior art as described above have the following problems.

That is, in the wireless charging of the magnetic induction method, the distance between the transmitting coil and the receiving coil is minimized and the transmitting coil and the receiving coil are properly aligned so that the magnetic field of the transmitting coil is maximally wound around the receiving coil. efficiency is maximized.

However, when using a wireless charger for actual industrial use, the spacing and alignment between the transmission coil and the reception coil may not be optimal, and it is necessary to transmit power to various receivers using one transmitter.

In addition, in this case, dynamic compensation using a capacitor is required so that the transmission coil and the power reception coil resonate at the magnetic field alternating frequency, but in general, wireless charging devices and methods of the prior art are mostly used when the structure of the transmission coil and the power reception coil is determined or The fixed coil compensation method is applied only when the distance between the transmission coil and the reception coil is determined, and as a result, the prior art wireless charging devices and methods are used when the distance or alignment between the transmission coil and the reception coil changes or When the shape of the receiving coil is changed, coil compensation is not properly performed, resulting in a decrease in wireless charging efficiency.

Therefore, in order to solve the problems of the prior art as described above, when the wireless charging device is used, when the distance between the power transmission coil and the power reception coil is changed or the degree of alignment is changed or the shape of the power reception coil is changed, dynamic It is desirable to provide a wireless charging device and method with a new structure configured to always maintain optimal wireless charging efficiency by controlling a compensation capacitor for resonating a power transmission coil and a power receiving coil, but all such requests have not yet been met. A satisfactory device or method has not yet been presented.

Korean Patent Publication No. 10-2021-0061030 (2021.05.27.) Korean Registered Patent Publication No. 10-1792134 (2017.10.25.)

The present invention is to solve the problems of the prior art as described above, and therefore, an object of the present invention is to apply a fixed coil compensation method with respect to a predetermined structure or interval between a transmission coil and a reception coil, so that the transmission coil and the reception coil In order to solve the problems of the prior art wireless charging devices and methods, which have limitations in that the wireless charging efficiency is reduced because proper coil compensation is not performed when the coil spacing or alignment or the shape of the receiving coil is changed, the transmitting coil and the receiving coil A wireless charging device having a dynamic coil compensation function configured to automatically optimize wireless charging efficiency by automatically matching impedances according to circumstances when the degree of arrangement of coils changes or when power is transmitted from a single transmitting coil to multiple receiving coils, and It is intended to provide a wireless charging method using this.

In addition, another object of the present invention is, as described above, when the distance or alignment between the power transmission coil and the power reception coil is changed or the shape of the power reception coil is changed, coil compensation is not properly performed, thereby reducing wireless charging efficiency. In order to solve the problems of the prior art wireless charging devices and methods, the received power is calculated by measuring the received voltage and received current, the transmitted power is calculated by measuring the transmitted voltage and transmitted current, and the received power is transmitted. The charging efficiency is calculated by dividing by , and the charging efficiency is continuously monitored to set each compensation capacitor to the capacitance value of the receiving coil compensation capacitor and the transmission coil compensation capacitor, in which the charging efficiency is maximized when the charging efficiency decreases. , A wireless charging device having a dynamic coil compensation function configured to always maintain optimal wireless charging efficiency by controlling a compensation capacitor for resonating a power transmission coil and a power receiving coil dynamically according to circumstances, and a wireless charging method using the same that you want to provide.

In order to achieve the above object, according to the present invention, in a wireless charging device having a dynamic coil compensation function, a power transmission unit configured to wirelessly transmit power through a power transmission coil; and a power receiving unit receiving power transmitted from the power transmitting unit through a power receiving coil, wherein the power transmitting unit includes: a power transmission voltage measurement unit for measuring a power transmission voltage; Transmission current measuring unit for measuring the transmission current; a power transmission coil compensator for controlling inductance of the power transmission coil; a power transmission and communication unit for transmitting and receiving various data including voltage and current measurement values; and controlling the overall operation of the power transmission unit, calculating and monitoring the charging efficiency based on the measured values measured by the transmission voltage measurement unit and the transmission current measurement unit and the data transmitted from the power reception unit. A wireless charging device with a dynamic coil compensation function is provided, characterized in that it comprises a power transmission control unit in which a process of controlling the power transmission coil compensator is performed so that the power transmission coil compensation unit is maximized.

Here, the power receiving unit may include a receiving current measuring unit for measuring a receiving current; a receiving voltage measuring unit for measuring a receiving voltage; a power receiving coil compensator for controlling inductance of the power receiving coil; A receiving communication unit for transmitting and receiving various data including voltage and current measurement values; and controlling the overall operation of the power receiving unit, calculating received power based on respective measurement values measured by the receiving voltage measuring unit and the receiving current measuring unit, and transmitting the received power to the power transmission unit, and transmitting the receiving power to the power transmitting unit, and the receiving coil compensation unit. It is characterized in that it is configured to include a power reception control unit that performs a process of obtaining an optimum value at which charging efficiency is maximized by controlling and transmitting the value to the power transmission unit.

In addition, the transmission unit may include a power transmission power unit for supplying power; and a switching circuit for constantly controlling charging current and voltage, wherein the power receiving unit includes: a rectifying unit for rectifying the received power signal; and a battery in which the received power is stored.

In addition, the power receiving control unit measures the receiving voltage and the receiving current through the receiving voltage measuring unit and the receiving current measuring unit, calculates the receiving power from the measured values, and transmits the received power to the power transmission control unit through the power receiving communication unit. The transmission control unit measures the transmission voltage and transmission current through the transmission voltage measurement unit and the transmission current measurement unit, calculates the transmission power from the measured values, and calculates the transmission power received by the power reception control unit It is characterized in that the processing of monitoring the charging efficiency is performed by repeatedly performing the process of calculating the charging efficiency based on the value divided by the transmitted power according to a predetermined setting.

Furthermore, when the power transmission control unit detects that the charging efficiency is out of a predetermined reference value or a reference range while monitoring the charging efficiency, the power reception control unit transmits a compensation command for the power reception coil to the power reception control unit, and the power reception control unit responds to the compensation command. Based on this, the capacitance of the receiving coil compensating capacitor of the receiving coil compensating unit is controlled to obtain an optimum value at which the charging efficiency is maximized among the values from the minimum value to the maximum value of the receiving coil compensating capacitor, and transmits the optimum value to the power transmission control unit. Based on the received optimum value of the power receiving coil compensation unit, the control unit determines the power failure of the power transmission coil compensation capacitor with the optimum value at which the charging efficiency is maximized among the values from the minimum value to the maximum value of the power transmission coil compensation capacitor of the power transmission coil compensation unit. It is characterized in that it is configured so that processing for controlling the capacity is performed.

In addition, the power transmission coil compensator includes a fixed capacitor C ₁ having a predetermined capacitance, a variable capacitor C _A including a plurality of capacitors having different capacitances connected in parallel and a switch connected to each capacitor. and a variable capacitor C _B comprising a fixed capacitor C ₂ having a predetermined capacitance, a plurality of capacitors having different capacitances and connected in parallel, and a switch connected to each capacitor. Thus, it is characterized in that the compensation capacitance value is changed and controlled by shorting or opening each capacitor of the variable capacitor through each switch.

In addition, in the power transmission coil compensation unit (reception coil compensation unit), fs is the switching frequency of the switching circuit, L ₁ (L ₂ ) is the inductance of the transmission coil (reception coil), and L _1max (L _2max ) is the transmission coil (reception coil) Coil) The maximum value of inductance, C ₁ (C ₂ ), is the value of the fixed capacitor C ₁ (C ₂ ) when it is assumed that the transmission coil (reception coil) compensation capacitance when the inductance of the transmission coil (reception coil) is the largest It is characterized in that it is set to a value that satisfies the following equation.

Moreover, when the minimum value of the inductance L ₁ (L ₂ ) of the transmitting coil (receiving coil) is assumed to be L _1min (L _2min ), the transmitting coil compensator (receiving coil compensating unit), the variable capacitor C _A (C _B ) is characterized in that the maximum value C _A,max (C _B,max ) is set to a value that satisfies the following equation.

In addition, in the transmitting coil compensator (receiving coil compensator), the value of each capacitor of the variable capacitor C _A (C _B ) is a multiple of the basic capacitance C ₀ (C ₀ , 2C ₀ , 4C ₀ , 8C ₀ , ...), and the basic capacitance C ₀ is characterized in that it is calculated using the following equation.

(Here, N means the total number of cases that can be combined with the fixed capacitor C ₁ (C ₂ ) according to the number of individual capacitors provided in the variable capacitor C _A (C _B ))

In addition, when charging starts, the wireless charging device measures the values of the power receiving voltage V ₂ and the receiving current I ₂ through the power receiving voltage measuring unit and the receiving current measuring unit, respectively, and uses the following equation to perform the switching. Receiving voltage values V 2 (t 1 ), V ₂ (t ₂ ), ..., V measured at each point in time t ₁ , t ₂ , ..., t _N at equal intervals during _the switching period T of _the circuit ₂ (t _N ) and the received current values I ₂ (t ₁ ), I ₂ (t ₂ ), ..., I ₂ (t _N ) to calculate the average received power P _2,av and transmit it to the transmission control unit Processing is performed through the faucet control unit,

Through the power transmission control unit, the average transmission power P _1,av is calculated in the same manner as the power reception control unit based on the measured values measured through the transmission voltage measurement unit and the transmission current measurement unit, and through the power reception control unit The charging efficiency is continuously monitored by repeating the process of calculating the charging efficiency E using the transmitted average received power P _2,av and the following equation according to a predetermined setting,

During monitoring, when it is detected that the charging efficiency is out of a predetermined reference value or standard range, it is determined that compensation of the power transmission coil and the power reception coil is necessary, and the variable capacitor of the power reception coil compensator is controlled to obtain a minimum value C ₂ to a maximum value C _{2 + CB.} Optimal capacitance C _{2,opt having the maximum efficiency among power receiving coil compensation capacitances up to , max} is obtained, and in a state where the capacitance of the receiving coil compensation unit is fixed to the optimum capacitance C _2,opt, the optimum capacitance C _{1 of the power transmission coil compensation unit; opt} is obtained in the same way as the power transmission coil compensator, and a process of controlling the capacitances of the power transmission coil compensator and the power reception coil compensator is performed according to each obtained optimum capacitance value.

Furthermore, according to the present invention, in the wireless charging method using the wireless charging device having the dynamic coil compensation function described above, the power receiving voltage measuring unit and the receiving current measurement of the wireless charging device are measured through the power receiving control unit of the wireless charging device. a receiving power calculation step of measuring the values of the receiving voltage and receiving current through the unit and calculating the average received power based on the measured values; The processing of measuring the values of the transmission voltage and the transmission current through the transmission voltage measurement unit and the transmission current measurement unit of the wireless charging device through the transmission control unit of the wireless charging device, respectively, and calculating the average transmission power based on the measured values a transmission power calculation step performed; a charging efficiency calculation and monitoring step in which charging efficiency is calculated and continuously monitored based on values of each received power and transmitted power through the power transmission control unit; Through the transmission control unit, when it is detected that the charging efficiency is out of a predetermined reference value or range during monitoring, optimal compensation capacitance for the transmission coil compensation unit and the reception coil compensation unit of the wireless charging device is calculated, and based on the calculated value There is provided a wireless charging method characterized in that it comprises a compensation step in which a process of controlling each compensation capacitance to an optimum value is performed.

As described above, according to the present invention, the received power is calculated by measuring the received voltage and the received current, the transmitted power is calculated by measuring the transmitted voltage and the transmitted current, the received power is divided by the transmitted power to calculate the charging efficiency, , Wireless having a dynamic coil compensation function configured to continuously monitor the charging efficiency and set each compensation capacitor to the capacitance value of the receiving coil compensation capacitor and the transmitting coil compensation capacitor, in which the charging efficiency is maximized when the charging efficiency decreases. By providing a charging device and a wireless charging method using the same, optimal wireless charging efficiency can always be maintained by dynamically controlling a compensation capacitor for resonating a power transmission coil and a power reception coil according to circumstances.

In addition, according to the present invention, as described above, when the degree of alignment between the transmission coil and the reception coil is changed or when power is transmitted from a single transmission coil to a plurality of reception coils, the impedance is automatically matched to automatically optimize the wireless charging efficiency. By providing a wireless charging device having a dynamic coil compensation function configured to be configured and a wireless charging method using the same, a fixed coil compensation method is applied to a predetermined structure or interval between a transmission coil and a reception coil, so that the transmission coil and the reception coil It is possible to solve the problems of the prior art wireless charging devices and methods, which have limitations in that wireless charging efficiency is reduced because proper coil compensation is not performed when the coil spacing or alignment or the shape of the power receiving coil is changed.

1 is a diagram schematically showing the overall configuration of a wireless charging device having a dynamic coil compensation function according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing specific configurations of a transmission voltage measurement unit and a reception voltage measurement unit of a wireless charging device having a dynamic coil compensation function according to an embodiment of the present invention shown in FIG. 1 .
FIG. 3 is a diagram schematically showing specific configurations of a transmission current measurement unit and a reception current measurement unit of a wireless charging device having a dynamic coil compensation function according to an embodiment of the present invention shown in FIG. 1 .
4 is a diagram schematically illustrating a charging operation of a wireless charging device having a dynamic coil compensation function according to an embodiment of the present invention shown in FIG. 1 .
FIG. 5 is a diagram schematically showing specific configurations of a transmitting coil compensating unit and a receiving coil compensating unit of a wireless charging device having a dynamic coil compensating function according to an embodiment of the present invention shown in FIG. 1 .
FIG. 6 is a diagram schematically showing a specific configuration of a variable capacitor of the compensation circuit shown in FIG. 5;
7 is a flowchart schematically showing the overall configuration of a wireless charging method using a wireless charging device having a dynamic coil compensation function according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, specific embodiments of a wireless charging device having a dynamic coil compensation function and a wireless charging method using the same according to the present invention will be described.

Here, it should be noted that the contents described below are only one embodiment for carrying out the present invention, and the present invention is not limited to the contents of the embodiments described below.

In addition, in the following description of the embodiments of the present invention, for parts that are the same as or similar to the contents of the prior art or are determined to be easily understood and implemented at the level of those skilled in the art, the detailed descriptions are provided to simplify the description. It should be noted that .

That is, in the present invention, as will be described later, since a fixed coil compensation method is applied to a predetermined structure or interval between the transmission coil and the reception coil, the distance or alignment between the transmission coil and the reception coil or the shape of the reception coil is changed. In order to solve the problems of the prior art wireless charging devices and methods, which had limitations in reducing wireless charging efficiency due to failure to properly compensate the coil, when the alignment degree of the transmission coil and the reception coil changed or multiple transmission coils were changed, The present invention relates to a wireless charging device having a dynamic coil compensation function configured to automatically optimize wireless charging efficiency by automatically matching impedances according to situations when power is transmitted to a power receiving coil, and a wireless charging method using the same.

In addition, as will be described later, the present invention has limitations in reducing wireless charging efficiency because coil compensation cannot be properly performed when the distance or alignment between the power transmission coil and the power reception coil changes or the shape of the power reception coil changes. In order to solve the problems of the prior art wireless charging devices and methods, the received power is calculated by measuring the received voltage and received current, the transmitted power is calculated by measuring the transmitted voltage and transmitted current, and the received power is divided by the transmitted power. By calculating the charging efficiency and continuously monitoring the charging efficiency, when the charging efficiency decreases, each compensation capacitor is configured to set the capacitance value of the receiving coil compensation capacitor and the transmission coil compensation capacitor where the charging efficiency is maximized, The present invention relates to a wireless charging device having a dynamic coil compensation function configured to always maintain optimal wireless charging efficiency by controlling a compensation capacitor for dynamically resonating a transmission coil and a power reception coil according to, and a wireless charging method using the same. .

Subsequently, with reference to the drawings, specific details of a wireless charging device having a dynamic coil compensation function and a wireless charging method using the same according to the present invention will be described.

First, referring to FIG. 1, FIG. 1 is a diagram schematically showing the overall configuration of a wireless charging device 10 having a dynamic coil compensation function according to an embodiment of the present invention.

As shown in FIG. 1, the wireless charging device 10 having a dynamic coil compensation function according to an embodiment of the present invention is roughly divided into a power transmission unit 11 that transmits power and a power transmission unit 11 that transmits power. It may be configured to include a power receiver 21 that receives power.

More specifically, the power transmission unit 11 includes a transmission power supply unit 12 for supplying power, a transmission voltage measurement unit 13 for measuring transmission voltage, and a transmission current measurement unit for measuring transmission current ( 14), a switching circuit 15 for constantly controlling the charging current and voltage, a power transmission coil compensator 16 for controlling the inductance of the power transmission coil 17, a power transmission coil 17 for transmitting a power signal, It may include a power transmission control unit 18 for controlling the overall operation of the power transmission unit 11 and a power transmission and communication unit 19 for transmitting and receiving various data including power and current measurement values.

In addition, the power receiving unit 21 includes a power receiving coil 27 for receiving a power signal transmitted from the power transmitting unit 11, a power receiving coil compensation unit 26 for controlling the inductance of the power receiving coil 27, A rectifying unit 25 for rectifying the received power signal, a receiving current measuring unit 24 for measuring receiving current, a receiving voltage measuring unit 23 for measuring receiving voltage, and a battery 22 storing the received power ), a power reception control unit 28 for controlling the overall operation of the power reception unit 21, and a power reception communication unit 29 for transmitting and receiving various data including power and current measurement values.

In addition, referring to FIGS. 2 and 3, FIG. 2 is a transmission voltage measurement unit 13 and a reception voltage measurement unit of the wireless charging device 10 having a dynamic coil compensation function according to the embodiment of the present invention shown in FIG. (23) is a diagram schematically showing the specific configuration, and FIG. 3 is a transmission current measurement unit 14 and a current reception current of the wireless charging device 10 having a dynamic coil compensation function according to the embodiment of the present invention shown in FIG. It is a drawing schematically showing the specific configuration of the measuring unit 24, respectively.

As shown in FIGS. 2 and 3 , the transmission voltage measurement unit 13 and the reception voltage measurement unit 23 may include a voltage multiplier amplifier for amplifying the voltage by a predetermined multiple, and the The transmission current measurement unit 14 and the reception current measurement unit 24 may include a current measurement amplifier for amplifying the current by a predetermined multiple.

Moreover, the wireless charger 10 having a dynamic coil compensation function according to an embodiment of the present invention may be configured to charge in stages according to the state of charge of the battery.

In more detail, referring to FIG. 4 , FIG. 4 is a diagram schematically illustrating a charging operation of the wireless charging device 10 having a dynamic coil compensation function according to the embodiment of the present invention shown in FIG. 1 .

As shown in FIG. 4, in the wireless charger 10 having a dynamic coil compensation function according to an embodiment of the present invention, the constant current charging step and constant voltage charging determined according to the type of battery under the control of the power transmission controller 18 described above. The battery may be configured to be charged in steps.

That is, the power transmission control unit 18 controls the switching circuit 16 to control the battery charging current to be a constant value in the constant current charging step, and to control the battery charging voltage to be a constant value in the constant voltage charging step.

In addition, in general, in wireless charging in a band of 10 kHz to 30 MHz, the charging efficiency can be increased by compensating the inductance of the power transmission coil and the inductance of the power receiving coil using a capacitor so that the inductor and the capacitor resonate.

At this time, the inductance of the transmission coil and the reception coil changes according to the relative position of the two coils and the relative shape of the two coils, and the transmission coil and the reception coil are not precisely aligned to a predetermined degree, or a single transmission coil receives various powers. Since the inductances of the transmission coil and the reception coil have various values when power is to be transmitted to the coil, charging efficiency can be increased by appropriately compensating the transmission coil and the reception coil dynamically each time charging occurs.

To this end, in the wireless charging device 10 having a dynamic coil compensation function according to an embodiment of the present invention, first, in the power receiving control unit 28, through the power receiving voltage measuring unit 23 and the receiving current measuring unit 24 The received voltage and received current are measured, and the received power is calculated from the measured values and transmitted to the power transmission control unit 18 through the power receiving communication unit 29.

In addition, the transmission control unit 18 measures the transmission voltage and transmission current through the transmission voltage measurement section 13 and the transmission current measurement section 14, calculates the transmission power from the measured values, and the power reception control section 28 The charging efficiency is calculated based on the value obtained by dividing the received power received by the calculated transmitted power, and the calculated charging efficiency is continuously monitored.

Continuously, during the monitoring of the charging efficiency, when it is detected that the charging efficiency is lowered to a certain level or more based on a predetermined standard, the power transmission control unit 18 commands the power receiving control unit 28 to compensate the power receiving coil 27, and power receiving The control unit 28 controls the power receiving coil compensation unit 26 based on this command to adjust the capacitance of the power receiving coil compensation capacitor.

At this time, the power reception control unit 28 communicates with the power transmission control unit 18 in each processing step to set the power reception coil compensation capacitor to the capacitance value of the power reception coil compensation capacitor at which the charging efficiency is maximized.

Next, the power transmission control unit 18 controls the power transmission coil compensation unit 26 to calculate the capacitance of the power transmission coil compensation capacitor having the maximum charging efficiency, and sets the power transmission coil compensation capacitor according to this value.

Therefore, through the process described above, the capacitance of the transmission coil compensation capacitor and the reception coil compensation capacitor are respectively controlled according to the capacitance at which the charging efficiency is maximized through the monitoring of the charging efficiency, so that the optimum charging efficiency is always obtained. can keep

More specifically, referring to FIG. 5, FIG. 5 shows a power transmission coil compensation unit 16 and a power reception coil compensation unit of a wireless charging device 10 having a dynamic coil compensation function according to the embodiment of the present invention shown in FIG. It is a diagram schematically showing the specific configuration of (26).

Here, in the circuit configuration shown in FIG. 5, R ₁ is the resistance obtained by adding the resistance of the power transmission coil 17 and the internal resistance of the power transmission power supply unit 12, R ₂ is the resistance of the power receiving coil 27, and R _L is the rectifying unit ( 25) and the battery 22, L ₁ is the inductance of the transmission coil 17, L ₂ is the inductance of the power reception coil 27, C ₁ is the case where the inductance of the transmission coil 17 is the largest Power transmission coil compensation capacitance, C ₂ is the power receiving coil compensation capacitance when the inductance of the power receiving coil 27 is the largest, C _A is a variable capacitance for dynamically compensating the power transmission coil 17, C _B is the power receiving coil 27 A variable capacitance, M, for dynamically compensating for , represents mutual inductances of the transmitting coil 17 and the receiving coil 27, respectively.

First, in a wireless charging device without a dynamic coil compensation function, the power transmission coil compensation capacitance C ₁ and the power reception coil compensation capacitance C ₂ are each at the switching frequency fs of the switching circuit 15 as shown in [Equation 1] below. It is set to form a series resonant circuit with the transmission coil inductance L ₁ and the reception coil inductance L ₂ .

[Equation 1]

In addition, the transmission coil inductance L ₁ and the reception coil inductance L ₂ are the maximum values L _1max and L _2max respectively when the structures of the two coils are the same and the distance between the two coils is the smallest and when the two coils are precisely overlapped and aligned, respectively. When the counterpart coil is removed, it has minimum values L _1min and L _2min , respectively.

That is, assuming that the rate of change of inductance L ₁ is m, m can be expressed as shown in [Equation 2] below, and typically has a value in the range of about 1.5 to 3.

[Equation 2]

In addition, in the case of dynamic coil compensation, the value of the fixed capacitor C ₁ shown in FIG. 2 may be set to a value that satisfies the following [Equation 3].

[Equation 3]

The relationship as described above is equally applied to the receiving coil L ₂ , and it should be noted that in the embodiment of the present invention, redundant descriptions are omitted for simplicity.

Continuing to refer to FIG. 6 , FIG. 6 is a diagram schematically illustrating a specific configuration of the variable capacitors C _A and C _B of the compensation circuit shown in FIG. 5 .

As shown in FIG. 6 , the adjustment of the compensation capacitor C _A can be configured such that the sum of C ₁ and C _A has a total of 16 values by connecting four capacitors in parallel, for example.

More specifically, the maximum value C _{A ,max} of the compensation capacitance C A can be determined as shown in [Equation 4] below by the expected minimum value L _1min of the inductance L ₁ .

[Equation 4]

That is, the compensation capacitor is, for example, as shown in FIG. 6, the four capacitances C ₀ , _{2C 0} , _{4C 0} , _{8C 0} are short-circuited _or By opening, the compensation capacitance value for the inductance L ₁ can be controlled to have a total of 16 values from C ₁ to C ₁ + C _A,max .

At this time, in FIG. 6 , C ₀ described above may be calculated using the following [Equation 5].

[Equation 5]

Here, in the above [Equation 5], the denominator may be changed according to the number of capacitors provided in the variable capacitor, that is, when N is the total number of combinations of compensation capacitances that can be derived according to the number of capacitors , the denominator of [Equation 5] may be determined as N-1.

In addition, compensation capacitors C ₂ and C _B of the power receiving coil compensator 26 may be set in the same manner as described above.

Here, in the embodiment shown in FIG. 6, the present invention has been described by taking as an example the case where the compensation capacitors (C _A , C _B ) are configured by connecting four capacitors in parallel, but the present invention is not necessarily limited to this case. That is, it should be noted that the present invention, in addition to the configurations shown in the embodiments of the present invention, can be configured by various modifications and changes as needed by those skilled in the art within the scope of not departing from the spirit and essence of the present invention.

Next, control of the power transmission coil compensator 16 and the power reception coil compensator 26 may be performed as follows.

First, when charging starts, the values of the receiving voltage V ₂ and the receiving current I ₂ are measured through the receiving voltage measuring unit 23 and the receiving current measuring unit 24, respectively, and based on the measured values, the average receiving power P _2, A process of calculating _av is performed through the power faucet control unit 28 .

More specifically, using the following [Equation 6], starting from the signal period starting point during the switching period T of the switching circuit 15, at equal intervals t ₁ , t ₂ , ..., at t _N time points, respectively Measured receiving voltage values V ₂ (t ₁ ), V ₂ (t ₂ ), ..., V ₂ (t _N ) and receiving current values I ₂ (t ₁ ), I ₂ (t ₂ ), ... , the average received power P _2,av is obtained from I ₂ (t _N ).

[Equation 6]

At the same time, the power transmission control unit 18 obtains the average transmitted power P _1,av in the same manner through the transmitted voltage measuring unit 13 and the transmitted current measuring unit 14, and the average transmitted through the power receiving control unit 28. The charging efficiency E is calculated using the received power P _2,av and the following [Equation 7], and the charging efficiency is continuously monitored by periodically repeating this process at predetermined intervals.

[Equation 7]

Continuously, during the monitoring of the charging efficiency, for example, when the charging efficiency falls below a predetermined reference value or a change exceeding the predetermined reference range is detected, dynamic compensation of the power transmission coil 17 and the power reception coil 27 is performed. If it is determined that this is necessary, the following processing is performed.

More specifically, first, the compensation capacitor of the power receiving coil compensation unit 26 is controlled to obtain C 2 _,opt having the maximum efficiency among a total of 16 power receiving coil compensation capacitances from the minimum value C ₂ to the maximum value C _2+CB,max . save

Then, in a state where the capacitance of the power receiving coil compensation unit 26 is fixed to C _2,opt, the optimum capacitance C _1,opt of the power transmission coil compensation unit 16 is obtained in the same way, and the power transmission coil 17 is obtained according to each optimum capacitance obtained. ) and the value of the receiving coil 27 can be controlled to compensate, so that the optimum charging efficiency can always be obtained, thereby improving the overall performance and efficiency of the wireless charging device.

Here, data exchange between the power transmission control unit 18 and the power reception control unit 28 is performed through the power transmission communication unit 19 and the power reception communication unit 29 in the process as described above.

Therefore, as described above, it is possible to implement the wireless charging device 10 having a dynamic coil compensation function according to an embodiment of the present invention, whereby coil compensation is automatically performed according to the position and shape of the charging coil and the receiving coil A wireless charging method can be implemented.

That is, referring to FIG. 7 , FIG. 7 is a flowchart schematically showing the overall configuration of a wireless charging method using the wireless charging device 10 having a dynamic coil compensation function according to an embodiment of the present invention.

As shown in FIG. 7, the wireless charging method according to an embodiment of the present invention is broadly divided, first, a wireless charging device (10) having a dynamic coil compensation function according to an embodiment of the present invention configured as shown in FIG. The processing of measuring the values of the receiving voltage and the receiving current through the receiving voltage measuring unit 23 and the receiving current measuring unit 24 of the ) and calculating the average receiving power based on the measured values is performed by the receiving control unit 28. The received power calculation step (S10) performed through the transmission voltage measurement unit 13 and the transmission current measurement unit 14 measures the values of the transmission voltage and transmission current, respectively, and calculates the average transmission power based on the measured values. The transmission power calculation step (S20) in which the calculation process is performed through the power transmission control unit 18 and the process of obtaining and continuously monitoring the charging efficiency based on the calculated values of each received power and transmitted power are performed by the transmission control unit 18 ), the charging efficiency calculation and monitoring step (S30), and when it is detected that the charging efficiency is out of a predetermined reference value or range during the monitoring, the optimal It may include a compensation step (S40) in which a process of calculating compensation capacitance and controlling each compensation capacitance to an optimal value based on the calculated value is performed through the power transmission control unit 18.

Here, the specific processing of each of the above steps (S10 to S40) may be configured as described above with reference to FIGS. 1 to 6 and [Equation 1] to [Equation 7], so a brief description is given here It should be noted that the detailed description has been omitted for the sake of clarity.

In addition, in the above-described embodiments of the present invention, for example, specific operations or principles of wireless charging or coil compensation, etc., are obvious to those skilled in the art or are easily understood and implemented by those skilled in the art by referring to documents in the prior art. It should be noted that a detailed description of what can be done has been omitted to simplify the description.

Therefore, as described above, it is possible to implement a wireless charging device having a dynamic coil compensation function and a wireless charging method using the same according to an embodiment of the present invention, whereby, according to the present invention, power reception by measuring power reception voltage and power reception current Calculate power, measure transmission voltage and transmission current to calculate transmission power, divide received power by transmission power to calculate charging efficiency, and continuously monitor charging efficiency to maximize charging efficiency when charging efficiency decreases. A wireless charging device having a dynamic coil compensation function configured to set each compensation capacitor to a capacitance value of a power receiving coil compensation capacitor and a power transmission coil compensation capacitor, and a wireless charging method using the same, are provided, so that the power transmission coil is dynamically Optimum wireless charging efficiency can always be maintained by controlling the compensation capacitor for resonating the power receiving coil.

In addition, according to the present invention, as described above, when the degree of alignment between the transmission coil and the reception coil is changed or when power is transmitted from a single transmission coil to a plurality of reception coils, the impedance is automatically matched to automatically optimize the wireless charging efficiency. By providing a wireless charging device having a dynamic coil compensation function configured to be configured and a wireless charging method using the same, a fixed coil compensation method is applied to a predetermined structure or interval between a transmission coil and a reception coil, so that the transmission coil and the reception coil It is possible to solve the problems of the prior art wireless charging devices and methods, which have limitations in that wireless charging efficiency is reduced because proper coil compensation is not performed when the coil spacing or alignment or the shape of the power receiving coil is changed.

In the above, the details of the wireless charging device having a dynamic coil compensation function according to the present invention and the wireless charging method using the same have been described through the embodiments of the present invention as described above, but the present invention is the contents described in the above embodiments. It is not limited to, and therefore, the present invention is capable of various modifications, changes, combinations, and substitutions according to design needs and other various factors by those skilled in the art to which the present invention belongs. I'd say it's a natural thing.

10. Wireless charging device with dynamic coil compensation
11. Transmission section 12. Transmission power section
13. Transmission voltage measurement unit 14. Transmission current measurement unit
15. Switching circuit 16. Transmission coil compensator
17. Transmission coil 18. Transmission control unit
19. Power transmission and communication part 21. Power receiving part
22. Battery 23. Receiving voltage measuring unit
24. Receiving current measurement unit 25. Rectification unit
26. Receiving coil compensating part 27. Receiving coil
28. Reception control unit 29. Reception communication unit

Claims (11)

In the wireless charging device having a dynamic coil compensation function,
a power transmission unit configured to wirelessly transmit power through a power transmission coil; and
It is configured to include a power reception unit that receives power transmitted from the power transmission unit through a power reception coil,
The transmission unit,
a transmission voltage measurement unit for measuring transmission voltage;
Transmission current measuring unit for measuring the transmission current;
a power transmission coil compensator for controlling inductance of the power transmission coil;
a transmission and communication unit for transmitting and receiving various data including voltage and current measurement values; and
The overall operation of the power transmission unit is controlled, and the charging efficiency is calculated and monitored based on the measured values measured by the power transmission voltage measurement unit and the transmission current measurement unit and the data transmitted from the power reception unit, so that the charging efficiency is determined. A wireless charging device having a dynamic coil compensation function, characterized in that it comprises a power transmission control unit in which a process of controlling the power transmission coil compensator is performed to maximize the power transmission coil compensation unit.
According to claim 1,
The power supply unit,
a receiving current measurement unit for measuring a receiving current;
a receiving voltage measuring unit for measuring a receiving voltage;
a power receiving coil compensator for controlling inductance of the power receiving coil;
A receiving communication unit for transmitting and receiving various data including voltage and current measurement values; and
Controls the overall operation of the power receiving unit, calculates received power based on the measured values measured by the receiving voltage measuring unit and the receiving current measuring unit, transmits the received power to the power transmitting unit, and controls the receiving coil compensation unit. A wireless charging device having a dynamic coil compensation function, characterized in that it comprises a power reception control unit that performs a process of obtaining an optimum value for maximizing charging efficiency and transmitting it to the power transmission unit.
According to claim 2,
The transmission unit,
a transmission power unit for supplying power; and
It is configured to further include a switching circuit for constantly controlling the charging current and voltage,
The power supply unit,
a rectifier for rectifying the received power signal; and
A wireless charging device having a dynamic coil compensation function, characterized in that configured to further include a battery in which the received power is stored.
According to claim 3,
The power control unit,
The receiving voltage and the receiving current are measured through the receiving voltage measuring unit and the receiving current measuring unit, and processing of calculating received power from the measured values and transmitting the received power to the power transmission control unit through the receiving communication unit is performed,
The power transmission control unit,
The transmission voltage and transmission current are measured through the transmission voltage measurement unit and the transmission current measurement unit, transmission power is calculated from the measured values, and based on a value obtained by dividing the transmission power received by the transmission control unit by the calculated transmission power A wireless charging device with a dynamic coil compensation function, characterized in that the process of calculating the charging efficiency is repeatedly performed according to a predetermined setting to perform a process of monitoring the charging efficiency.
According to claim 4,
The power transmission control unit,
When it is detected that the charging efficiency is out of a predetermined reference value or reference range during the monitoring of the charging efficiency, a compensation command for the power receiving coil is transmitted to the power receiving control unit;
The power control unit,
Based on the compensation command, the capacitance of the receiving coil compensating capacitor of the receiving coil compensating unit is controlled to obtain an optimum value at which the charging efficiency is maximized among the values from the minimum value to the maximum value of the receiving coil compensating capacitor, and transmitted to the power transmission control unit. and
The power transmission control unit,
Controls the capacitance of the power transmission coil compensation capacitor to the optimum value at which the charging efficiency is maximized among the values from the minimum value to the maximum value of the power transmission coil compensation capacitor of the power transmission coil compensation unit based on the received optimum value of the power reception coil compensation unit. Wireless charging device having a dynamic coil compensation function, characterized in that configured to perform the processing of.
According to claim 5,
The transmission coil compensation unit,
It is configured to include a fixed capacitor C ₁ having a predetermined capacitance, a variable capacitor C _A including a plurality of parallel-connected capacitors having different capacitances and a switch connected to each capacitor,
The receiving coil compensation unit,
By including a fixed capacitor C ₂ having a predetermined capacitance, a variable capacitor C _B comprising a plurality of parallel-connected capacitors having different capacitances and a switch connected to each capacitor,
Wireless charging device having a dynamic coil compensation function, characterized in that configured to change and control the compensation capacitance value by shorting or opening each capacitor of the variable capacitor through each switch.
According to claim 6,
The transmission coil compensation unit (reception coil compensation unit),
fs is the switching frequency of the switching circuit, L ₁ (L ₂ ) is the inductance of the transmitting coil (receiving coil), L _1max (L _2max ) is the maximum value of the inductance of the transmitting coil (receiving coil), C ₁ (C 2 ) is the transmitting coil (C ₂ ) Characterized in that the value of the fixed capacitor C ₁ (C ₂ ) is set to a value that satisfies the following equation when the compensation capacitance of the transmitting coil (receiving coil) is the case where the inductance of the coil (receiving coil) is the largest. A wireless charging device with a dynamic coil compensation function.

According to claim 7,
The transmission coil compensation unit (reception coil compensation unit),
When the minimum value of the inductance L ₁ (L ₂ ) of the transmitting coil (receiving coil) is L _1min (L _2min ), the maximum value of the variable capacitor C _A (C _B ) C _A,max (C _B,max ) A wireless charging device having a dynamic coil compensation function, characterized in that set to a value that satisfies the following equation.

According to claim 8,
The transmission coil compensation unit (reception coil compensation unit),
The value of each capacitor of the variable capacitor C _A (C _B ) is set to a multiple of the basic capacitance C ₀ (C ₀ , 2C ₀ , 4C ₀ , 8C ₀ ,...),
The basic capacitance C ₀ is a wireless charging device having a dynamic coil compensation function, characterized in that calculated using the following equation.

(Here, N means the total number of cases that can be combined with the fixed capacitor C ₁ (C ₂ ) according to the number of individual capacitors provided in the variable capacitor C _A (C _B ))
According to claim 9,
The wireless charging device,
When charging starts, the power receiving voltage V ₂ and the receiving current I ₂ are measured through the power receiving voltage measuring unit and the receiving current measuring unit, respectively, at equal intervals during the switching period T of the switching circuit by using the following equation. Receiving voltage values V ₂ (t ₁ ), V ₂ (t ₂ ), ..., V ₂ (t _N ) and receiving current measured at each time point t 1 , t ₂ , ..., _{t N} A process of calculating the average received power P _2,av from the values I ₂ (t ₁ ), I ₂ (t ₂ ), ..., I ₂ (t _N ) and transmitting the result to the power transmission control unit is performed through the power reception control unit. becomes,

Through the power transmission control unit, the average transmission power P _1,av is calculated in the same manner as the power reception control unit based on the measured values measured through the transmission voltage measurement unit and the transmission current measurement unit, and through the power reception control unit The charging efficiency is continuously monitored by repeating the process of calculating the charging efficiency E using the transmitted average received power P _2,av and the following equation according to a predetermined setting,

During monitoring, when it is detected that the charging efficiency is out of a predetermined reference value or standard range, it is determined that compensation of the power transmission coil and the power reception coil is necessary, and the variable capacitor of the power reception coil compensator is controlled to obtain a minimum value C ₂ to a maximum value C _{2 + CB.} Among the receiving coil compensation capacitances up to _,max, the optimal capacitance C _2,opt with the maximum efficiency is obtained,
In a state in which the capacitance of the power receiving coil compensation unit is fixed to the optimum capacitance C _2,opt, the optimum capacitance C _1,opt of the power transmission coil compensation unit is obtained in the same manner as in the power transmission coil compensation unit, and the optimum capacitance value A wireless charging device having a dynamic coil compensation function, characterized in that it is configured to perform processing for controlling the capacitance of the transmitting coil compensator and the receiving coil compensator, respectively.
In the wireless charging method using the wireless charging device having a dynamic coil compensation function according to any one of claims 1 to 10,
The processing of measuring the values of the receiving voltage and the receiving current through the receiving control unit of the wireless charging device, the receiving voltage measuring unit and the receiving current measuring unit of the wireless charging device, respectively, and calculating the average receiving power based on the measured values a receiving power calculation step performed;
The processing of measuring the values of the transmission voltage and the transmission current through the transmission voltage measurement unit and the transmission current measurement unit of the wireless charging device through the transmission control unit of the wireless charging device, respectively, and calculating the average transmission power based on the measured values a transmission power calculation step performed;
a charging efficiency calculation and monitoring step in which charging efficiency is calculated and continuously monitored based on values of each received power and transmitted power through the power transmission control unit; and
Through the transmission control unit, when it is detected that the charging efficiency is out of a predetermined reference value or range during monitoring, optimal compensation capacitance for the transmission coil compensation unit and the reception coil compensation unit of the wireless charging device is calculated, and based on the calculated value A wireless charging method characterized in that it comprises a compensation step in which a process of controlling each compensation capacitance to an optimum value is performed.

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