KR20230077351A - Wireless power charging apparatus for efficient managing of charging state and method thereof - Google Patents

Abstract

The present invention relates to a wireless power charging device for efficiently managing charging status, and a method therefor. The present invention comprises: at least one transmitting end that transmits power using power provided from a power supply unit and each includes a transmitting resonator unit including one capacitor and one inductor; at least one receiving end that receives power transmitted from the at least one transmitting end and each including a receiving resonator including one capacitor and one inductor, and a load performing charging using the received power; and a control unit that proceeds with wireless charging by determining the output current of the at least one transmitting end using the mutual inductance between the at least one transmitting end and the at least one receiving end, and adjusts the output current of the at least one transmitting end by using the importance of the at least one receiving end with respect to the at least one transmitting end depending on whether the current receiving power of the at least one receiving end reaches the target receiving power, and the received power control direction for adjusting the received power of the at least one receiving end.

Description

Wireless power charging device and method for efficiently managing charging state

The present invention relates to a wireless power charging device and method for efficiently managing a charging state, and to a wireless power charging device and method capable of maximizing the power required by a receiving end by monitoring the received power of the receiving end.

Wireless power transmission refers to supplying power to electronic devices wirelessly instead of wired, and since devices requiring power can be charged wirelessly without connecting to a power outlet, related research is being actively conducted. Magnetic induction method, magnetic resonance method, microwave method, etc. are being studied for wireless power transmission technology.

A wireless power transmitter includes a transmitter that wirelessly transmits power and a receiver that receives the transmitted power. The transmitter transmits power to the receiver by generating a magnetic field and radiating it to the receiver. For power transmission, a transmitter and a receiver use coils, and when they have the same resonant frequency, maximum power transfer can occur in a wireless power transmitter.

On the other hand, wireless charging may be performed by configuring one or more transmitters and receivers. In this case, one transmitter can transmit power to a plurality of receivers, and one receiver can receive power from a plurality of transmitters. In this situation, when the power received from a receiving end is smaller or greater than the required power and needs to be adjusted, the transmitting end supplying power to the receiving end needs to control the transmit power. However, there is more than one transmitter that supplies power to the receiver that needs to adjust the received power, and the received power due to the power transmitted from one transmitter is different for each receiver, and each transmitter transmits power to other receivers in addition to the corresponding receiver. There is a problem that it is difficult to determine whether to control the transmission power of .

The present invention relates to a wireless power charging device and method for efficiently managing a charging state capable of maximally providing required power in a receiving end by monitoring received power of a receiving end.

In addition, the present invention relates to a wireless power charging device and method capable of controlling transmission power of a transmission end and received power of a reception end in consideration of the extent to which power transmitted from a transmission end affects a reception end.

The present invention transmits power using power supplied from the power supply unit and includes at least one transmitting end each including a transmission resonator unit including one capacitor and one inductor; at least one receiving end each including a reception resonator that receives the power transmitted from the at least one transmitting end and includes a capacitor and an inductor and a load that performs charging using the received power; Wireless charging is performed by determining the output current of the at least one transmitting end using mutual inductance between the at least one transmitting end and the at least one receiving end, and whether the current received power of the at least one receiving end reaches the target received power. A control unit for adjusting the output current of the at least one transmitting end using the importance of the at least one receiving end to the at least one transmitting end and a received power control direction for adjusting the received power of the at least one receiving end according to It relates to a wireless power charging device that does.

Here, the control unit may determine the importance by considering the degree of influence of the power transmitted from the transmitting end on each receiving end between one transmitting end and at least one receiving end.

In addition, the control unit determines the level of importance according to the magnitude of mutual inductance between any one transmitting end and at least one receiving end, and has a non-zero mutual inductance between any one transmitting end and at least one receiving end. The level of importance may be determined by setting the total number of receiving ends to be the highest value of the importance and subtracting a predetermined value from the highest value for the next rank.

In addition, the control unit maintains the output current of the at least one transmitting end at the current state when the current received power of the at least one receiving end reaches the target receiving power, and the current receiving power of the at least one receiving end reaches the target reception power. When all of the power falls below or exceeds the power, the output current of the at least one transmitter may be adjusted.

In addition, the control unit may determine whether the current reception power of the at least one receiving terminal reaches the target reception power by using [Equation 4].

[Equation 4]

At this time, d _k is any one of (+1), 0, and (-1) in the received power control direction for the k-th receiving end.

In addition, the control unit may determine whether the current reception power of the at least one receiving terminal falls short of or exceeds the target reception power by using [Equation 5].

[Equation 5]

At this time, d _k is any one of (+1), 0, and (-1) in the received power control direction for the k-th receiving terminal.

In addition, if the current received power of a portion of the at least one receiving end falls short of or exceeds the target received power, the control unit determines whether the current received power of at least one receiving end having the highest importance for the at least one transmitting end reaches the target receiving power. The output current of the transmitter may be adjusted according to whether or not the

In addition, the control unit may determine whether the current reception power of at least one receiving end having the highest importance for the at least one transmitting end has reached a target reception power by using [Equation 6].

[Equation 6]

At this time, D _t is any one of (+1), 0, and (-1) in the received power control direction for the receiving end having the highest importance for the t-th transmitting end.

In addition, the control unit may adjust the output current of the at least one transmitting terminal using [Equation 7].

[Equation 7]

At this time, S _t is any one of increasing, decreasing, and maintaining in the current control direction of the t-th transmitter

W _tk is the importance of the k-th receiver to the t-th transmitter

d _k is any one of (+1), 0, and (-1) in the received power control direction for the k-th receiving terminal.

On the other hand, the present invention transmits power using power supplied from a power supply unit, and receives power transmitted from at least one transmitting end each including a transmission resonator including one capacitor and one inductor, and one transmitting end. determining a mutual inductance between a receiving resonator including a capacitor of and one inductor and at least one receiving end each including a load performing charging using the received power; determining an output current of the at least one transmitting end using mutual inductance between the at least one transmitting end and the at least one receiving end, and performing wireless charging; Receive power control direction for adjusting the importance of the at least one receiving end to the at least one transmitting end and the received power of the at least one receiving end according to whether the current received power of the at least one receiving end reaches the target receiving power. It relates to a wireless power charging method comprising the step of adjusting the output current of the at least one transmitting terminal by using.

Here, the process of adjusting the output current of the transmitting end includes: checking the total number of receiving ends having mutual inductance other than '0' between any one transmitting end and at least one receiving end; The step of setting the total number as the highest value of the importance and determining the level of importance by subtracting a predetermined value from the highest value as the next priority.

In addition, the process of adjusting the output current of the transmitting end may include maintaining the output current of the at least one transmitting end at the current state when the current reception power of the at least one receiving end reaches the target reception power; The method may include adjusting an output current of the at least one transmitting node when the current reception power of the at least one receiving node falls below or exceeds the target reception power.

In addition, the process of adjusting the output current of the transmitting end may include the current reception of at least one receiving end having the highest importance for the at least one receiving end when the current reception power of a portion of the at least one receiving end falls short of or exceeds the target receiving power. The method may include adjusting an output current of the transmitter depending on whether or not the power reaches a target reception power.

In the present invention, even when a receiving end receives power from a plurality of transmitting ends or when a transmitting end transmits power to a plurality of receiving ends, when the received power of the receiving end is less than or exceeds the target reception power, the transmit power of the transmitting end is controlled to control the receiving end. Received power can be adjusted. In addition, in the relationship between the transmitting end and the receiving end, the power supply can be efficiently controlled since the transmitting end and the receiving end having the highest influence are identified and power is supplied in consideration of the importance of the receiving end to the transmitting end.

1 is a diagram showing the configuration of a wireless power charging device according to an embodiment of the present invention.
2 is a diagram for explaining a transmitting end and a receiving end of a wireless power charging device according to an embodiment of the present invention.
3 is a diagram for explaining a connection relationship between a plurality of transmitting ends and a plurality of receiving ends of a wireless power charging device according to an embodiment of the present invention.
4 is a diagram for explaining a method of determining whether charging is in progress in a wireless power charging device according to an embodiment of the present invention.
5 is a diagram for explaining a method of determining mutual inductance in a wireless power charging device according to an embodiment of the present invention.
6 is a diagram for explaining a method of controlling an output current of a transmitter in a wireless power charging device according to an embodiment of the present invention.
7 is a flowchart for explaining the operation of the wireless power charging device 10 according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with drawings. In describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

1 is a diagram showing the configuration of a wireless power charging device 10 according to an embodiment of the present invention.

Referring to FIG. 1, the wireless power charging device 10 of the present invention includes a power supply unit 100, an amplification unit 110, a communication unit 120, a sensing unit 130, a resonator unit 140, a rectifier unit 150, It includes a conversion unit 160 and a control unit 170.

The power supply unit 100 supplies power to the wireless power charging device 10 of the present invention, and supplies AC (Alternating Current) or DC (Direct Current) power, for example.

The amplification unit 110 amplifies power supplied from the power supply unit 100 and may be configured as a power amplifier.

The communication unit 120 is for communication inside the external device or the wireless power charging device 10 of the present invention, and is a short-range communication means such as Bluetooth or Wi-fi or LTE or 5G (5G) It may include a communication means capable of communicating by accessing a mobile communication network according to various mobile communication standards, such as the like.

The sensing unit 130 detects voltage or current at a predetermined position of the wireless power charging device 10 of the present invention, and may include various sensors.

The resonator 140 transmits power by resonance between coils, and includes at least one transmit resonator and at least one receive resonator including a capacitor and an inductor, respectively.

The rectifier 150 is for changing AC current into DC current, and may be configured as a rectifier. The rectifying unit 150 rectifies the current generated in the reception resonance unit.

The conversion unit 160 is to keep the voltage provided for charging constant in order to meet the voltage condition for charging, and can be configured as a DC-DC converter, and the voltage according to the conversion ratio. can be adjusted.

The control unit 140 controls the wireless power charging device 10 as a whole of the present invention, such as determining the mutual inductance of the resonator 140 and the current or voltage of the transmitter so that wireless power charging can proceed with maximum efficiency.

2 is a diagram for explaining the transmitting end 200 and the receiving end 210 of the wireless power charging device 10 according to an embodiment of the present invention.

Referring to FIG. 2 , the wireless power charging device 10 of the present invention includes a transmitting end 200 for transmitting power and a receiving end 210 for receiving power to enable charging.

The transmitter 200 includes a control unit 170, a power supply unit 100, an amplifier 110, and a transmission resonator 220, and the receiver 210 includes a reception resonator 230, a rectifier 150, and a conversion unit. (160) and load R _L . 2 shows the control unit 170 as the transmitting end 200, the control unit 170 is configured to control the wireless power charging device 10 of the present invention as a whole, including not only the transmitting end 200 but also the receiving end 210. can

In addition, although not shown in FIG. 2 , the sensing unit 130 may sense voltage or current at predetermined positions of the transmitting end 200 and the receiving end 210 and communicate with each other through the communication unit 120 . For example, current or voltage sensed through Bluetooth communication may be transmitted/received or control information may be transmitted/received.

A description of each character shown in FIG. 2 is as follows.

V _P : Output voltage of the amplifier 110

I _P : output current of the transmitting end 200

C _P : capacitance of the transmission resonator 220

L _P : Self-inductance of the transmitting resonator 220

M : mutual inductance

I _S : receiving current of the receiving terminal 210

C _S : capacitance of the receiving resonator 230

L _S : self-inductance of the receiving resonator 230

V _R : output voltage of the rectifier 150

V _Out : Charging voltage of the load of the receiving end 210

R _L : Load impedance of the receiving end 210

3 is a diagram for explaining a connection relationship between a plurality of transmitting ends 200a, 200b, and 200c and a plurality of receiving ends 210a, 210b, and 210c of the wireless power charging device 10 according to an embodiment of the present invention.

Hereinafter, a case in which power is transmitted from a plurality of transmitters to a plurality of receivers will be described, and the same can be applied to the case of transmitting power from one transmitter or receiving power from one receiver.

Referring to FIG. 3, the wireless power charging device 10 according to an embodiment of the present invention includes first to t transmitting terminals 200a, 200b, and 200c and first to q receiving terminals 210a, 210b, and 210c. It is configured so that power charging can proceed in the first through q-th receiving nodes 210a, 210b, and 210c using the power transmitted by the first to t-th transmitting nodes 200a, 200b, and 200c. At this time, each of the first to t-th transmitting ends 200a, 200b, and 200c may include the same or similar configuration as the transmitting terminal 200 described in FIG. 2, and the first to q-th receiving ends 210a, 210b, and 210c may include the same or similar configuration as the receiving end 210 of FIG. 2 .

In addition, each of the first to t-th transmitting ends 200a, 200b, and 200c and the first to q-th receiving ends 210a, 210b, and 210c have the same size of each component such as capacitance, inductance, and impedance as other transmitting or receiving ends. It can be configured or configured differently from each other. In addition, the power supply unit 100 and the control unit 170 are configured as one component and applied to the entire wireless power charging device 10 of the present invention, and the amplifier 110, the transmission resonance unit 220, the sensing unit ( 130) is composed of a plurality of components included in each of the first to t-th transmission terminals 200a, 200b, and 200c, and includes a reception resonance unit 230, a rectification unit 150, a conversion unit 160, and a sensing unit 130 may be composed of a plurality of components included in each of the first to qth receiving terminals 210a, 210b, and 210c. In addition, the communication unit 120 is composed of one component in the first to t-th transmitting ends 200a, 200b, and 200c and applied to the entire transmitting end, and included in each of the first to q-th receiving ends 210a, 210b, and 210c. It can consist of multiple components. In addition, the control unit 170 controls the power supplied to the first through t-th transmitting terminals 200a, 200b, and 200c by using the power supplied from the power supply unit 100.

A mutual inductance equal to M _tq is generated between the first to t-th transmitting ends 200a, 200b, and 200c and the first to q-th receiving ends 210a, 210b, and 210c between each transmitting end and each receiving end. In addition, when foreign matter invades the charging area, since the foreign matter also has an inductance and a load of the foreign matter, between the first to t transmitting terminals 200a, 200b, and 200c and the foreign material, the first to q receiving terminals 210a, 210b, and 210c Mutual inductance also occurs between the

4 is a diagram for explaining a method of determining whether charging is in progress in the wireless power charging device 10 according to an embodiment of the present invention.

In order to minimize power consumption, the wireless power charging device 10 of the present invention operates in a power saving mode before the receiving end enters the charging area of the first through t-th transmitting ends 200a, 200b, and 200c. In the power saving mode, when an object enters the charging area of the transmitting end, the controller 170 checks whether a receiving end capable of wireless charging is within the charging area of the transmitting end, and proceeds with wireless charging. At this time, since foreign substances may enter the charging area, after checking whether there is an arbitrary object in the charging area, it is determined whether the object is a chargeable receiving end or a foreign substance.

Hereinafter, the t-th transmitter 200c will be described, and the same or similar can be applied to other transmitters.

4 is a diagram showing an equivalent circuit when an arbitrary object enters the charging area of the t-th transmitter 200c. As shown in FIG. 4, the equivalent circuit includes two MOS-FETs, a resistor, a capacitor, and an inductor, and descriptions of each character are as follows.

CCS _t (400): Current control unit of the t-th transmitter 200c

w: operating angular frequency of the t-th transmitter 200c

I _mt : Output current of the t-th transmitter 200c

V _Pt : Input voltage of the t th transmitter 200c

R _Pt : internal resistance of the coil of the t-th transmitter 200c

C _Pt : capacitance of the t-th transmitter 200c

L _Pt : inductance of the t th transmitter 200c

Zu.o 410: Impedance of a predetermined object viewed from the t th transmitter 200c

Z _int : Impedance viewed from the t th transmitter (200c) to all receivers

CCS _t (400) controls the current supplied to the t-th transmitter 200c, and for example, according to the control signal received from the MCU (Micro Controller Unit), the t-th in a predetermined current unit such as 0.01 (A) The amount of current supplied to the transmitter 200c is controlled.

When the sensing unit 130 senses the input voltage or output current of the t-th transmitting end 200c and transmits the detected input voltage or output current to the control unit 170, the control unit calculates the impedance (Z _int ) using [Equation 1] Decide.

[Equation 1]

When a predetermined object is located within the charging area of the t-th transmitter 200c, an impedance Zu.o is generated due to the object, which causes the impedance Z _int to increase. Through this, when the size of the impedance (Z _int ) exceeds a predetermined threshold value, it is determined that an arbitrary object is located within the charging area. Thereafter, it is determined whether an object is a receiving end capable of wireless power charging or a foreign substance that is difficult to charge, and wireless charging is performed in the case of the receiving end, and charging is not performed in the case of a foreign object.

When an object is identified as a receiving end, the control unit 170 checks the number of receiving ends using a short-range communication means such as Bluetooth to proceed with wireless charging, and determines the value and sign of mutual inductance between the transmitting end and the receiving end.

5 is a diagram for explaining a method of determining mutual inductance in the wireless power charging device 10 according to an embodiment of the present invention.

The controller 170 may determine the mutual inductance through the method described in Application No. 10-2019-0092894 (filed date: 2019.07.31), and the present invention uses the mutual inductance determined through the method described in Application No. 10-2019-0092894. available.

For example, as shown in FIG. 5, the equivalent circuit of the wireless power charging device includes the first to t-th transmission resonance circuit units 300, 320, and 340, the first to t-th power supply units (V _S1 , V _{S2, and} V _St ), and the first to q-th reception units. A case consisting of the resonance circuit units 310 , 330 , and 350 and the load resistors R _{L1 ,} R _{L2 , and} R _Lq will be described. When power is supplied to the first to t-th transmission resonance circuit units 300, 320, and 340 from the first to t-th power supply units V _S1 , V _{S2 , and} V _St , the input voltage (V _P1 , V _{P2 ,} V _Pt ) are generated, and reception voltages V _{R1 ,} V _{R2 , and} V _Rq are generated in the first to qth reception resonance circuit units 310 , 330 , and 350 .

At this time, a mutual inductance value for efficiently transmitting power from the first to t-th transmission resonance circuit units 300, 320, and 340 to the first to q-th reception resonance circuit units 310, 330, and 350 is determined as in [Equation 2].

[Equation 2]

At this time, M _tq : Mutual inductance of the t-th transmission resonance circuit unit and the q-th reception resonance circuit unit

I _Pt : Input current of the t-th transmission resonant circuit

w: operating angular frequency of the t-th transmission resonance circuit

R _Lq : load resistance of the qth reception resonance circuit

V _Rq : receiving voltage of the qth receiving resonant circuit unit

Z _Sq : Impedance of the qth reception resonant circuit

C _Sq : capacitor of the qth receiving resonant circuit

L _Sq : Self inductance of the qth receiving resonant circuit

R _Sq : internal resistance of the qth receiving resonant circuit

In the present invention, in order to determine the mutual inductance value, the mutual inductance value is determined through [Equation 2] in a state in which power is supplied to only one transmission resonance circuit unit and power supply is cut off to the other resonance circuit unit.

For example, after supplying current I _P1 only to the first transmission resonance circuit unit 300 and cutting off the power supply to the second transmission resonance circuit unit to the t-th transmission resonance circuit unit 320 , 340 , each other related to the first transmission resonance circuit unit 300 Determine the inductance (M _11, M ₁₂ to M _1q ). Thereafter, the current I _P2 is supplied only to the second transmission resonance circuit unit 320 and the power supply is cut off to the first transmission resonance circuit unit 300 and the third transmission resonance circuit unit (not shown) to the t-th resonance circuit unit 340. Mutual inductances (M _{21 ,} M ₂₂ to M _2q ) related to the second transmission resonant circuit unit 320 are determined. All mutual inductance values can be determined by proceeding to the t transmission resonant circuit unit 340 in the same way.

Meanwhile, when the mutual inductance value is determined, a sign of the mutual inductance is determined, and the sign of the mutual inductance is determined as in [Equation 3].

[Equation 3]

if) V _Rq,in-phase > V _{Rq,out of phase} (+)

if) V _Rq,in-phase < V _{Rq,out of phase} (-)

At this time, V _Rq,in-phase is the voltage generated in the q-th receiving resonance circuit when a predetermined same magnitude and same-phase current is supplied to the reference transmission resonance circuit and the transmission resonance circuit for determining the code, and V _{Rq,out of phase} is a voltage generated in the q-th receiving resonance circuit unit when currents of the same magnitude and opposite phases flow to the reference transmission resonance circuit unit and the transmission resonance circuit unit for determining the code. At this time, the supply of power to other transmission resonance circuit units other than the reference transmission resonance circuit unit and the transmission resonance circuit unit for determining the code is cut off.

If the sign of the mutual inductance is (+), it indicates the case where the phase is the same, and (-) indicates the case where the phase is opposite. In addition, the reference transmission resonant circuit part can be arbitrarily determined, and the signs of mutual inductances related to the reference transmission resonance circuit part are all (+).

For example, if the first transmission resonance circuit unit 300 is determined as the reference transmission resonance circuit unit, the signs of mutual inductances M ₁₁ to M _1q related to the first transmission resonance circuit unit 300 are all (+).

The first transmission resonance circuit unit 300 as a reference for determining the sign of the mutual inductance (M ₂₁ to M _2q ) related to the second transmission resonance circuit unit 320 and the second transmission resonance circuit unit 320 for determining the code A current having the same magnitude and the same phase is supplied to the receiving voltage of the first receiving resonance circuit unit to the qth receiving resonance circuit unit 310 or 350 . Thereafter, currents of the same magnitude and opposite phases are supplied to the first transmission resonance circuit unit 300 and the second transmission resonance circuit unit 320 to measure the received voltages of the first reception resonance circuit unit to the qth reception resonance circuit unit 310,350. do. When the reception voltages of the first reception resonance circuit unit to the q-th reception resonance circuit unit 310 or 350 are measured, a mutual inductance sign is determined using [Equation 3]. In this way, the signs of the mutual inductances of the third transmission resonance circuit unit (not shown) to the t-th transmission resonance circuit unit 340 may be determined.

6 is a diagram for explaining a method of controlling an output current of a transmitter in a wireless power charging device 10 according to an embodiment of the present invention.

In the present invention, since power is transmitted and received between at least one transmitter or receiver, the control unit 170 sets a subset that can be regarded as an independent transmitter or receiver unaffected by other transmitters or receivers in order to increase charging efficiency. . If subsets are set, output currents I _{P1 ,} I P2 , and I _Pt of each of the first through t-th transmitting terminals 200a, 200b _, and 200c for maximum efficiency can be determined more quickly.

The controller 170 sets a subset using a matrix of mutual inductance (M _tq ). In the matrix, a row denotes a transmitting end, a column denotes a receiving end, and i row and j column denote mutual coupling between the ith transmitting end and the jth receiving end. In this configured state, if all the elements of the row and column preceding the predetermined mutual inductance are '0', it is regarded as a separate subset from the mutual inductance. As an example, FIG. 6 shows the wireless charging device 10 as first to fourth transmitting ends (Tx ₁ , Tx ₂ , Tx ₃ , Tx ₄ ) and first to third receiving ends (Rx ₁ , Rx ₂ , Rx ₃ ). If configured, it shows how to determine the subset.

In FIG. 6 , the first receiving end (Rx ₁ ) receives power from the first and second transmitting ends (Tx ₁ and Tx ₂ ), and the second receiving end (Rx ₂ ) receives power from the second and third transmitting ends (Tx ₂ and Tx _{3 )} . ), and the third receiving terminal (Rx ₃ ) receives power from the fourth transmitting terminal (Tx ₄ ). Mutual inductance (M ₄₃ ) between the third receiving terminal (Rx ₃ ) and the fourth transmitting terminal (Tx ₄ ) constitutes a separate subset because elements in the previous row and column are all '0'. Accordingly, the mutual inductances M ₁₁ , M ₂₁ , M ₂₂ , and M ₃₂ constitute one subset, and the mutual inductance M ₄₃ constitute one subset. That is, the third receiver (Rx ₃ ) and the fourth transmitter (Tx ₄ ) constitute one subset, and the remaining transmitters and receivers constitute one subset.

을 구하며, 이때, Particle Swarm Optimization, Simmulated Annealing, Generic Algorithm 등을 이용할 수 있다.When the subsets are determined, an optimization algorithm is applied to each subset to determine output currents I _{P1 ,} I _P2 , and I _Pt of the first through t-th transmitting terminals 200a, 200b, and 200c. For example, in consideration of the limiting conditions when charging the wireless charging device 10

, and at this time, Particle Swarm Optimization, Simmulated Annealing, Generic Algorithm, etc. can be used.

When the output currents I _{P1 ,} I _{P2 , and} I _Pt of the first to t-th transmitting ends 200a , 200b , and 200c are determined, the control unit 170 transmits the determined current to the first through q-th receiving ends 210a , 210b , and 210c. ) to allow charging to proceed. At this time, the first to qth receiving ends 210a, 210b, and 210c charge with maximum efficiency through the output currents I _P1, I _{P2, and} I _Pt of the first to t transmitting ends 200a, 200b, and 200c. To do this, it is necessary to monitor the power received from each receiving end and control the output currents (I _P1, I _P2, I _Pt ) of each transmitting end.

For example, when there are a plurality of transmitters and receivers, the power transmitted by one transmitter affects the plurality of receivers, and a higher power than the target received power (hereinafter referred to as 'target received power') is received by one receiver. Since the other receiving end can receive power lower than the target receiving power, the output of each transmitting end so that the power received at each receiving end (hereinafter referred to as 'current receiving power') reaches the target receiving power of each receiving end as much as possible. It is necessary to control the current.

To this end, the control unit 170 generates an importance matrix using mutual inductances determined between the first through t-th transmitting ends 200a, 200b, and 200c and the first through q-th receiving ends 210a, 210b, and 210c. Here, the importance indicates the degree of influence of the power transmitted from the transmitting end to each receiving end between any one transmitting end and each receiving end, and is determined according to the size of the mutual inductance between any one transmitting end and each receiving end. Mutual inductance It is preferable to use the absolute value of . In addition, the importance matrix relates to a matrix representing importance between each transmitter and each receiver and is determined using mutual inductance determined between each transmitter and each receiver. For example, the mutual inductance between each transmitter and each receiver can be represented by a mutual inductance matrix as shown in [Table 1], where T _xt is the t-th transmitter, R _xq is the q-th receiver, and M _tq in [Table 1] is the mutual inductance between the t th transmitter and the q th receiver, and a _t represents the total number of receivers having a non-zero mutual inductance with the t th transmitter.

_{Rx1 Rx2} ... _Rxq a _Tx1 M _-11 M _-12 ... M _1q a _{1 Tx2} M _-21 M _-22 ... _M2q a ₂ ... ... ... ... ... ... _Txt M _t1 M _t2 ... _Mtq a _t

When the mutual inductance between the transmitting end and the receiving end is determined as shown in [Table 1], the control unit 170 determines the importance metric as shown in [Table 2]. In [Table 2], W _tq represents the importance of the qth receiving node to the tth transmitting node. indicate

_{Rx1 Rx2} ... _{Rxq Tx1 W11} W ₁₂ ... W _{1q Tx2 W21 W22} ... W _2q ... ... ... ... ... _Txt W _t1 W _t2 ... _Wtq

Since the importance is determined between any one transmitting end and each receiving end, the maximum value of the importance is the total number (a _t ) of the transmitting end and the receiving end having non-zero mutual inductance. It is determined by subtracting a predetermined value from the maximum value, and the predetermined value is preferably '1'. The minimum value of importance is '0', and when mutual inductance is '0' between any one transmitting end and each receiving end, the minimum value becomes '0'.

For example, when wireless charging is performed by transmitting power from the first and second transmitting ends to the first to third receiving ends, the mutual inductance is determined between each transmitting end and the receiving end, and a mutual inductance matrix is generated as shown in [Table 3]. Let's see if it happens. In [Table 3], the number of receivers having non-zero mutual inductance between the first transmitting end and each receiving end is 2, and the number of receivers having non-zero mutual inductance between the second transmitting end and each receiving end is Since there are two, a ₁ and a ₂ become '2'.

_{Rx1 Rx2 Rx3} a _Tx1 120 95 0 2 _Tx2 0 -45 80 2

When mutual inductance matrices between the first and second transmitting ends and the first to third receiving ends are generated, the control unit 170 determines an importance matrix as shown in [Table 4] using the mutual inductance.

_{Rx1 Rx2 Rx3 Tx1} 2 One 0 _Tx2 0 One 2

In [Table 4], since the receiving end having the highest mutual inductance between the first transmitting end and the first to third receiving ends is the first receiving end, the receiving end having the greatest importance for the first transmitting end is the first receiving end, and since a ₁ is '2', W ₁₁ becomes '2'. Since the second receiving terminal has the second highest mutual inductance, '1' is subtracted from the maximum value, and the third receiving terminal becomes '0' as the minimum value. In the case of the second transmitting end, since the receiving end having the highest mutual inductance is the third receiving end, the receiving end having the greatest importance for the second transmitting end is the third receiving end, and since a ₂ is '2', the importance (W ₂₃ ) becomes '2'. Since the second receiving terminal has the second highest mutual inductance, '1' is subtracted from the maximum value, and the first receiving terminal becomes '0' as the minimum value.

Meanwhile, the control unit 170 checks the current reception power of each reception unit using the reception voltage or reception current of each reception unit transmitted from the sensing unit 130 and determines whether the target reception power has been reached in each reception unit. In each receiver, if the target reception power is not reached, the reception power should be increased. If the target reception power is reached, the current state should be maintained, and if the target reception power is exceeded, the reception power should be decreased. To this end, the control unit 170 determines the received power control direction matrix for each receiving end as shown in Table 5.

_{Rx1 Rx2} ... _Rxq target receiving power P _T1 P _T2 ... P _Tq current receiving power P _C1 P _C2 ... P _Cq Receiving power control direction d ₁ d ₂ ... d _q

In [Table 5], P _Tq is the target received power of the q-th receiving node 210c, P _Cq is the current received power of the q-th receiving node 210c, and d _q is the received power control direction for the q-th receiving node 210c. '+1' indicates that the current reception power does not reach the target reception power and the reception power must be increased, and '-1' indicates that the current reception power exceeds the target reception power and the reception power must be decreased. '0' indicates that the current reception power reaches the target reception power and the reception power should be maintained. For example, power control direction metrics for the first to third receiving ends may be shown in [Table 6]. In [Table 6], since the current received power exceeds the target received power for the first receiving end, the received power control direction is set to '-1', and for the second receiving end, since the current received power is less than the target received power, '+1' is set. And the third receiving terminal becomes '0' because the current received power has reached the target received power.

_{Rx1 Rx2 Rx3} target receiving power 5 5 5 current receiving power 8 2 5 Receiving power control direction -One +1 0

When the power control direction matrix of each receiving end is determined, the controller 170 adjusts the power transmitted to each receiving end by controlling the output current of each transmitting end. At this time, since the power transmitted from one transmitting end affects at least one receiving end, for efficient power transmission, the receiving power control direction of all receiving ends or the receiving power control direction of the receiving end having the highest importance for each transmitting end is considered. Controls the output current of the transmitter.

Specifically, the control unit 170 first checks whether the current reception power of all receiving terminals has reached the target reception power by using [Equation 4].

[Equation 4]

의 값이 '0'이 되고, 어느 하나 이상의 수신단에서의 현재 수신전력이 목표 수신전력에 미달하거나 초과한 경우에는 하나 이상의 수신단에서의 수신 전력 제어 방향이 '+1' 또는 '-1' 이므로

의 값이'0'을 초과하게 된다. 따라서, 제어부(170)는

의 값이 '0'인 경우에는 현 상태를 유지시키고,

의 값이 '0'을 초과하는 경우 [수학식 5]를 이용하여 모든 수신단의 현재 수신전력이 목표 수신전력에 미달하거나 또는 초과하였는지 확인한다.When the current reception power of all receiving ends reaches the target reception power, the direction of control of the receiving power of each receiving end becomes '0'.

When the value of is '0' and the current received power in one or more receiving terminals falls below or exceeds the target received power, the received power control direction in one or more receiving terminals is '+1' or '-1'.

The value of exceeds '0'. Therefore, the controller 170

If the value of is '0', the current state is maintained,

If the value of exceeds '0', using [Equation 5] Check whether the current reception power of all receiving terminals falls short of or exceeds the target reception power.

[Equation 5]

는 '0'이 되고, 모든 수신단에서 현재 수신전력이 목표 수신전력에 미달하거나 초과한 경우에는

는 '-1' 또는 '+1'이 된다. 따라서 제어부(170)는

가 '-1' 또는 '+1'인 경우에는 모든 수신단에서 현재 수신전력이 목표 수신전력에 도달하지 못하였거나 초과한 것으로 판단하여 각 송신단의 출력 전류를 제어하여 각 수신단에 전송되는 전력을 조절한다. 또한,

가 '0'인 경우에는 각 송신단에 대한 가장 큰 상호 인덕턴스를 갖는 중요도가 가장 높은 수신단의 수신전력이 모두 목표 수신전력에 도달하였는지 [수학식 6]을 이용하여 확인한다.If the current received power of one or more receiving ends reaches the target receiving power, the change in the received power of the corresponding receiving end is '0'.

becomes '0', and if the current reception power falls short of or exceeds the target reception power in all receiving terminals,

becomes '-1' or '+1'. Therefore, the controller 170

When is '-1' or '+1', it is determined that the current received power does not reach or exceeds the target reception power at all receiving ends, and the output current of each transmitting end is controlled to adjust the power transmitted to each receiving end. . also,

When is '0', it is confirmed using [Equation 6] whether the received power of the receiving end having the highest importance with respect to each transmitting end reaches the target receiving power.

[Equation 6]

At this time, D _t is the received power control direction for the receiving end having the highest importance for the t th transmitting end.

가 '0'인 경우에는 각 송신기에 대한 중요도가 가장 높은 수신단의 현재 수신전력이 모두 목표 수신 전력에 도달한 것으로 판단하여 현재의 상태를 유지시키고,

가 '0'을 초과한 경우에는 각 송신단의 출력 전류를 제어하여 각 수신단에 전송되는 전력을 조절한다. 일 예로, 제1 및 제2 송신단에 대한 중요도가 가장 높은 수신단에 대한 수신 전력 제어 방향을 나타내면 [표 7]과 같다. [표 7]에서 제1 송신단에 대한 중요도가 가장 높은 수신단은 현재 수신 전력이 목표 수신 전력을 초과하였으므로 수신 전력 제어 방향이 '-1'이 되고, 제2 송신단에 대한 중요도가 가장 높은 수신단은 현재 수신 전력이 목표 수신 전력에 도달하였으므로 '0'이 된다.The control unit 170

When is '0', it is determined that the current received power of the receiving end having the highest importance for each transmitter has reached the target received power, and the current state is maintained;

[0040] When [i] exceeds '0', the power transmitted to each receiving end is adjusted by controlling the output current of each transmitting end. As an example, the received power control direction for the receiving end having the highest importance for the first and second transmitting ends is shown in [Table 7]. In [Table 7], since the current received power of the receiving end with the highest importance for the first transmitting end exceeds the target receiving power, the received power control direction becomes '-1', and the receiving end with the highest importance for the second transmitting end is currently Since the received power has reached the target received power, it becomes '0'.

D _t Tx1 -One Tx2 0

If output current control of each transmitting end is required to adjust the current reception power of each receiving end, the controller 170 controls the output current of each transmitting end using [Equation 7].

[Equation 7]

At this time, S _t is the current control direction of the t th transmitter

W _tk is the importance of the k-th receiver to the t-th transmitter

d _k is the received power control direction for the k th receiving terminal

The controller 170 increases the output current of the t-th transmitter when 'S _t >0', decreases the output current of the t-th transmitter when ' _{S t <} 0', and In this case, the output current of the t th transmitter is maintained. For example, when power is transmitted from the first and second transmitting ends to the first to third receiving ends, the importance between each transmitting end and each receiving end may be summarized as shown in [Table 8].

_{Rx1 Rx2 Rx3 Tx1} 2 One 0 _Tx2 0 One 2

Among these, when d ₁ is (-1), d ₂ is (+1), and d ₃ is (-1), S _t is determined as follows.

Since S ₁ is less than 0, the control unit 170 reduces the output current of the first transmission end, and since S ₂ is less than 0, the control unit 170 reduces the output current of the second transmission end.

7 is a flowchart for explaining the operation of the wireless power charging device 10 according to an embodiment of the present invention.

Referring to FIG. 7 , when an object enters the charging area of the first through t-th transmitting terminals 200a, 200b, and 200c, the control unit 170 checks the object (700) and determines that the object can be wirelessly charged. In the case of the receiving end (yes in 710), charging proceeds, and in the case of foreign matter (no in 710), charging is not performed. When charging is in progress, the control unit 170 determines the mutual inductance between the first to t-th transmitting ends 200a, 200b, and 200c and the first to q-th receiving ends 210a, 210b, and 210c, and sets a subset for each receiving end. By determining the output current of the first through t-th transmitting terminals 200a, 200b, and 200c, charging proceeds (720).

Thereafter, the control unit 170 monitors the charging state of the receiving end and checks whether the current received power of the first through qth receiving ends 210a, 210b, and 210c all reach the target received power. If it reaches (Yes in 730), the output current of the first to t-th transmitting terminals 200a, 200b, and 200c is maintained at the current state (770), and if it does not reach it (No in 730), the first to q-th receiving terminals It is checked whether the current reception powers of (210a, 210b, and 210c) fall below or exceed the target reception power. In case of less than or exceeding (Yes in 740), the importance of the first to qth receiving ends 210a, 210b, and 210c to the first to tth transmitting ends 200a, 200b, and 200c and the first to qth receiving ends 210a , 210b, 210c) to adjust the output current of the first to t-th transmitting terminals 200a, 200b, and 200c using the received power control direction (760). In addition, if it does not fall below or exceed (No in 740), it is checked whether the current reception powers of the reception terminals having the highest importance for the first through t-th transmission terminals 200a, 200b, and 200c reach the target reception power. If it reaches (Yes in 750), the output current of the first to t-th transmitting terminals 200a, 200b, and 200c is maintained at the current state (770), and if it does not reach (No in 750), the first to t-th transmission terminals 200a, 200b, and 200c are maintained. By using the importance of the first to qth receiving ends 210a, 210b, and 210c for the transmitting ends 200a, 200b, and 200c and the received power control direction for the first to qth receiving ends 210a, 210b, and 210c, the first The output currents of the through t-th transmitters 200a, 200b, and 200c are adjusted (760).

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention.

Therefore, the scope of the present invention is not limited to the described embodiments, and should be defined by not only the scope of the claims to be described later, but also those equivalent to the scope of these claims.

100: power supply unit 110: amplification unit
120: communication unit 130: detection unit
140: resonance unit 150: rectification unit
160: conversion unit 170: control unit

Claims (13)

In the wireless power charging device,
at least one transmitting end that transmits power using the power provided from the power supply unit and each includes a transmission resonator unit including one capacitor and one inductor;
at least one receiving end each including a reception resonator that receives the power transmitted from the at least one transmitting end and includes a capacitor and an inductor and a load that performs charging using the received power;
Wireless charging is performed by determining the output current of the at least one transmitting end using mutual inductance between the at least one transmitting end and the at least one receiving end, and whether the current received power of the at least one receiving end reaches the target received power. A control unit for adjusting the output current of the at least one transmitting end using the importance of the at least one receiving end to the at least one transmitting end and a received power control direction for adjusting the received power of the at least one receiving end according to device to do.
According to claim 1,
wherein the control unit determines the degree of importance between one transmitting end and at least one receiving end by considering the degree of influence of the power transmitted by the transmitting end on each receiving end.
According to claim 1,
The control unit determines a level of importance according to the magnitude of mutual inductance between one transmitting end and at least one receiving end,
The level of importance is determined by setting the total number of receiving ends having mutual inductance other than '0' between any one transmitting end and at least one receiving end to the highest value of the importance, and subtracting a predetermined value from the highest value as the next priority. device to do.
According to claim 1,
The control unit maintains an output current of the at least one transmitting terminal at a current state when the current receiving power of the at least one receiving terminal reaches the target receiving power,
Apparatus for adjusting the output current of the at least one transmitting end when the current receiving power of the at least one receiving end falls below or exceeds the target receiving power.
According to claim 4,
The control unit determines whether the current reception power of the at least one receiving terminal has all reached the target reception power using [Equation 4].
[Equation 4]

At this time, d _k is any one of (+1), 0, and (-1) in the received power control direction for the k-th receiving end.
According to claim 4,
The control unit determines whether the current reception power of the at least one receiving end falls below or exceeds the target reception power by using [Equation 5].
[Equation 5]

At this time, d _k is any one of (+1), 0, and (-1) in the received power control direction for the k-th receiving end.
According to claim 1,
The control unit determines whether the current received power of at least one receiving end having the highest importance for the at least one transmitting end reaches the target receiving power when the current received power of a part of the at least one receiving end falls below or exceeds the target receiving power. A device for adjusting the output current of the transmitting end according to.
According to claim 7,
The control unit determines whether the current received power of at least one receiving end having the highest importance for the at least one transmitting end has reached a target received power by using [Equation 6].
[Equation 6]

At this time, D _t is any one of (+1), 0, and (-1) in the received power control direction for the receiving end having the highest importance for the t-th transmitting end.
According to claim 1,
The control unit controls the output current of the at least one transmitting terminal using [Equation 7].
[Equation 7]

At this time, S _t is any one of increasing, decreasing, and maintaining in the current control direction of the t-th transmitter
W _tk is the importance of the k-th receiver to the t-th transmitter
d _k is any one of (+1), 0, and (-1) in the received power control direction for the k-th receiving terminal.
In the wireless power charging method,
Transmits power using the power supplied from the power supply unit, and receives the power transmitted from at least one transmitting end each including a transmission resonator including one capacitor and one inductor and the at least one transmitting end, and includes one capacitor and one determining a mutual inductance between a receiving resonator including an inductor and at least one receiving terminal each including a load that performs charging using the received power;
determining an output current of the at least one transmitting end using mutual inductance between the at least one transmitting end and the at least one receiving end, and performing wireless charging;
Receive power control direction for adjusting the importance of the at least one receiving end to the at least one transmitting end and the received power of the at least one receiving end according to whether the current received power of the at least one receiving end reaches the target receiving power. and adjusting an output current of the at least one transmitting terminal using
According to claim 10,
The process of adjusting the output current of the transmitting end,
checking the total number of receiving ends having mutual inductance other than '0' between any one transmitting end and at least one receiving end;
and determining a level of importance by setting the total number as the highest value of the importance and subtracting a predetermined value from the highest value as the next priority.
According to claim 10,
The process of adjusting the output current of the transmitting end,
maintaining an output current of the at least one transmitting end at a current state when the current receiving power of the at least one receiving end reaches the target receiving power;
and adjusting an output current of the at least one transmitting node when the current receiving power of the at least one receiving node falls below or exceeds the target receiving power.
According to claim 10,
The process of adjusting the output current of the transmitting end,
When the current received power of a portion of the at least one receiving end falls below or exceeds the target received power, the current received power of at least one receiving end having the highest importance for the at least one transmitting end reaches the target received power according to whether or not the current received power reaches the target received power. A method comprising adjusting an output current of a transmitting end.

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