KR102268156B1 - Wireless power receivig apparatus, wireless power receivig method, and wireless power transmission system - Google Patents

Abstract

The wireless power receiver includes a power receiver that receives power wirelessly transmitted from the wireless power transmitter, a battery that receives current generated by power from the power receiver, and the residual energy of the power receiver when the transfer of current is stopped. and a timing controller for setting a transfer start condition for starting transfer of the current based on the current transfer.

Description

A wireless power receiving device, a wireless power receiving method, and a wireless power transmitting system {WIRELESS POWER RECEIVIG APPARATUS, WIRELESS POWER RECEIVIG METHOD, AND WIRELESS POWER TRANSMISSION SYSTEM}

The present disclosure relates to a wireless power receiving apparatus, a wireless power receiving method, and a wireless power transmitting system.

A study on wireless power transmission (WPT) was started to overcome the increased inconvenience of wired power supply and the limitation of the existing battery capacity due to the explosive increase in various electric devices including portable devices. Among them, research on short-range wireless power transmission is focused.

Wireless power transmission technology largely includes an electromagnetic induction method using a coil, a resonance method using resonance, and a RF/microwave radiation method that converts electrical energy into microwaves and transmits them.

When energy is accumulated in a resonator (resonant circuit) in a conventional resonance type wireless power receiver, the accumulated energy is transferred to a load (eg, a battery). In particular, the wireless power receiver transfers energy to a load when the current flowing through the resonator is maximum.

Embodiments have been devised to solve the above-described problem or other problems, and to provide a wireless power receiving device, a wireless power receiving method, and a wireless power transmitting system that transmit energy to a load without loss.

A wireless power receiver according to an embodiment includes a power receiver that receives power wirelessly transmitted from the wireless power transmitter, a battery that receives a current generated by power from the power receiver, and power when the transfer of current is stopped and a timing controller for setting a transfer start condition for starting transfer of current based on the residual energy of the receiver.

The power receiver may include a resonator including an inductor and a capacitor, and a first comparator for outputting a voltage difference between both ends of the capacitor, and the residual energy may be a voltage difference between both ends of the capacitor.

The timing control unit may determine, as a transfer start condition, whether a time elapsed from after the voltage difference across the capacitor reaches the first voltage level as a transfer start condition, and start transfer of the current when the transfer start condition is satisfied .

If the voltage difference between both ends of the capacitor is negative when the current transfer is stopped, the timing controller may decrease the first period to set the transfer start condition.

If the voltage difference between both ends of the capacitor at the time of stopping the transfer of the current is positive, the timing controller may increase the first period to set the transfer start condition.

The first period is increased or decreased by 1/n times of one period of the resonant frequency of the resonator, and n may be an integer.

The first period is set to 1/m times of one period of the resonant frequency of the resonator, and m may be an integer.

The power receiver further includes a switch connected between the resonator and the battery, and a second comparator for outputting a voltage difference between both ends of the switch, and the timing controller is configured to respond to a voltage difference between both ends of the switch when the transfer of current is stopped. Based on it, it is possible to further set a transfer stop condition for stopping the transfer of current.

When the voltage difference between both ends of the switch is positive, the timing controller may set the transfer stop condition such that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is increased.

When the voltage difference between both ends of the switch is negative, the timing controller may set the transfer stop condition such that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is reduced.

The inductor and capacitor are connected in series.

A method of receiving power from a wireless power transmitter performed by a wireless power receiver including a power receiver, a battery, and a timing controller according to an embodiment, the method comprising: the power receiver, from the wireless power transmitter Receiving the power transmitted wirelessly, the power receiving unit, under the control of the timing control unit, transferring the current generated by the power to the battery, and the timing control unit, the power receiving unit when the transmission of the current is stopped and setting, based on the residual energy, a transfer initiation condition for initiating transfer of the current.

The power receiver may include a resonator including an inductor and a capacitor, and a first comparator for outputting a voltage difference between both ends of the capacitor, and the residual energy may be a voltage difference between both ends of the capacitor.

The step of delivering the current generated by the electric power to the battery is a step in which the timing control section determines, as a delivery start condition, whether a time elapsed from after the voltage difference across the capacitor reaches a first voltage level is a first period , and the timing controller controlling the power receiver to start the transfer of current when the transfer start condition is satisfied.

The setting of the transfer start condition may include setting the transfer start condition by decreasing the first period if the voltage difference between both ends of the capacitor is negative when the timing controller stops the transfer of the current.

The setting of the transfer start condition may include setting the transfer start condition by increasing the first period if the voltage difference between both ends of the capacitor is positive when the timing controller stops the transfer of the current.

The first period is increased or decreased by 1/n times of one period of the resonant frequency of the resonator, and n may be an integer.

The first period is set to 1/m times of one period of the resonant frequency of the resonator, and m may be an integer.

The power receiver further includes a switch connected between the resonator and the battery, and a second comparator for outputting a voltage difference between both ends of the switch, wherein the method includes: Based on it, it may further include the step of setting a transfer stop condition to stop the transfer of the current.

The step of setting the transfer stop condition includes: if the voltage difference between both ends of the switch is positive, setting the transfer stop condition so that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is increased may include

The step of setting the transfer stop condition includes: if the voltage difference between both ends of the switch is negative, setting the transfer stop condition so that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is reduced may include

A wireless power transfer system includes a wireless power transmitter that wirelessly transmits power, and a wireless power receiver according to an embodiment.

According to embodiments, there is an effect that can implement fast charging of the wireless power receiving device.

According to the embodiments, there is an effect of minimizing power loss.

According to embodiments, there is an effect of reducing power consumption of the wireless power transmission apparatus.

1 is a conceptual diagram for explaining the overall operation of a wireless power transfer system.
2 is a block diagram schematically illustrating an apparatus for transmitting power wirelessly and an apparatus for receiving power wirelessly according to embodiments.
3 is a diagram specifically illustrating a part of an apparatus for transmitting power wirelessly and an apparatus for receiving power wirelessly according to an embodiment.
4 is a flowchart illustrating a method of controlling a wireless power receiving apparatus according to an embodiment.
5 and 6 are graphs when power transmission of the wireless power receiving apparatus is performed.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar elements throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness of some layers and regions are exaggerated.

In addition, throughout the specification, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

1 is a conceptual diagram for explaining the overall operation of a wireless charging system.

As shown in FIG. 1 , the wireless charging system includes a wireless power transmission device 100 and at least one wireless power reception device 200a , 200b , and 200c .

The wireless power transmitter 100 may form an electrical connection with the wireless power receivers 200a, 200b, and 200c. For example, the wireless power transmitter 100 may transmit wireless power in the form of electromagnetic waves to the wireless power receivers 200a, 200b, and 200c.

The wireless power transmitter 100 may wirelessly provide power to the plurality of wireless power receivers 200a, 200b, and 200c. For example, the wireless power transmitter 100 may transmit power to the plurality of wireless power receivers 200a, 200b, and 200c through a resonance method. When the wireless power transmitter 100 adopts the resonance method, the distance between the wireless power transmitter 100 and the plurality of wireless power receivers 200a, 200b, and 200c may be preferably 30m or less. In addition, when the wireless power transmitter 100 adopts the electromagnetic induction method, the distance between the wireless power transmitter 100 and the plurality of wireless power receivers 200a, 200b, and 200c may be preferably 10 cm or less.

The wireless power receiving apparatuses 200a, 200b, and 200c may receive wireless power from the wireless power transmitting apparatus 100 and charge a battery provided therein.

Meanwhile, the wireless power transmission apparatus 100 may perform communication with the wireless power reception apparatuses 200a, 200b, and 200c at the same time as power transmission. For example, the wireless power transmitter 100 may transmit a control signal for disabling the wireless charging function to each of the wireless power receivers 200a, 200b, and 200c. The wireless power receiving device receiving the disable control signal of the wireless charging function from the wireless power transmitting device 100 may disable the wireless charging function.

2 is a block diagram schematically illustrating an apparatus for transmitting power wirelessly and an apparatus for receiving power wirelessly according to embodiments.

As shown in FIG. 2 , the wireless power transmission apparatus 100 includes a power transmission unit 110 , a control unit 120 , a display unit 130 , and a storage unit 140 .

The power transmitter 110 may provide power required by the wireless power transmitter 100 and wirelessly provide power to the wireless power receiver 200 . Here, the power transmitter 110 may supply power in the form of an AC waveform, and may convert the power of the DC waveform into an AC waveform using an inverter to supply the power of the AC waveform. The power transmitter 110 may receive power from a battery built in the wireless power transmitter 100 or an external power source to supply power to the wireless power receiver 200 . Those skilled in the art will readily understand that the power transmitter 110 is not limited as long as it is a means capable of providing power of an AC waveform.

The controller 120 may control overall operations of the apparatus 100 for transmitting power wirelessly. The controller 120 may control the overall operation of the wireless power transmitter 100 by using an algorithm, a program, or an application required for control read from the storage 140 . The controller 120 may be implemented in the form of a CPU, a microprocessor, or a mini computer. Accordingly, the controller 120 may be named as a controller, or may be referred to as a micro controlling unit (MCU) according to implementation.

The controller 120 may transmit data by adjusting the amount of power transmitted from the power transmitter 110 . Specifically, the controller 120 modulates data to generate a control signal provided to the power transmitter 110 , and the power transmitter 110 may adjust the voltage level according to the control signal. The time for which energy is charged in the power receiver 210 of the wireless power receiver 200 varies according to the voltage level. Then, the controller 230 may demodulate the data transmitted from the wireless power transmitter 100 based on different times.

For example, the control unit 120 may transmit a charging function control signal for controlling the charging function of the wireless power receiving apparatus 200 through the power transmitting unit 110 . The charging function control signal may be a control signal for controlling the power receiving unit 210 of the specific wireless power receiving device 200 to enable or disable the charging function.

Also, the wireless power receiver 200 may include at least one of a power receiver 210 , a battery 220 , a controller 230 , and a storage 240 .

The power receiver 210 may wirelessly receive power transmitted from the wireless power transmitter 100 . Here, the power receiver 210 may receive power in the form of an AC waveform.

The controller 230 may control the overall operation of the apparatus 200 for receiving power wirelessly. The controller 230 may control the overall operation of the wireless power transmitter 250 by using an algorithm, a program, or an application required for control read from the storage 240 . The control unit 230 may be implemented in the form of a CPU, a microprocessor, or a mini computer, but is not limited thereto.

Also, as described above, the controller 230 may receive data through the power receiver 210 . Data transmitted from the wireless power transmitter 100 may be demodulated based on different times when energy is charged in the power receiver 210 of the wireless power receiver 200 .

The storage unit 140 and the storage unit 240 are a flash memory type, a solid state disk type, an SDD type, a silicon disk drive type, a multimedia card micro type, Card type memory (such as SD or XD memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only (EEPROM) memory), a programmable read-only memory (PROM), and a register may include at least one type of storage medium.

The wireless power transmitter 100 and the wireless power receiver 200 will be described in detail with reference to FIGS. 3 to 6 .

3 is a diagram specifically illustrating a part of a wireless power transmitter and a wireless power receiver according to an embodiment, and FIG. 4 is a flowchart illustrating a control method of the wireless power receiver according to an embodiment, and FIGS. 5 and FIG. 6 is a graph when power transmission of the wireless power receiving device is performed.

As shown in FIG. 3 , the power transmitter 110 of the wireless power transmitter 100 transfers electromagnetic energy to the wireless power receiver 200 .

Specifically, the power transmitter 110 includes an input voltage Vin and a source resonator. The source resonator includes a capacitor C1 and an inductor L1. Among the input voltages Vin, a voltage applied to the first capacitor C1 may be represented by V1, and a current flowing through the inductor L1 may be represented by I1.

The capacitor C1 and the inductor L1 may resonate by the input voltage Vin. In this case, the frequency of the input voltage Vin may be the same as the resonant frequency of the capacitor C1 and the inductor L1.

The magnitude, frequency, and phase of the input voltage Vin may be controlled by the control signal PCS of the controller 120 . The magnitude of the input voltage Vin may be changed corresponding to the bit of data to be transmitted by the wireless power transmission apparatus 100 .

The inductor L1 transmits power through mutual resonance with the second inductor L2 of the wireless power receiver 200 . The degree of mutual resonance occurring between the inductor L1 and the second inductor L2 is affected by the mutual inductance M.

The power receiver 210 of the wireless power receiver 200 receives energy from the wireless power transmitter 100 . The power receiver 210 includes a target resonator, switches SW1 and SW2 , comparators 212 and 213 , and a timing controller 214 .

The target resonator includes an inductor L2 and a capacitor C2 connected in series. Power charged through mutual resonance in the target resonator is charged.

The switches SW1 and SW2 selectively connect the target resonator to ground or a load. The switch SW1 is connected between the node N1 and the ground, and the switch SW2 is connected between the node N1 and the node N2.

Specifically, the switch SW1 electrically connects the node N1 and the ground according to the control signal CS1 output from the timing controller 214 so that the target resonator can be charged with power. At this time, the switch SW2 is turned off according to the control signal CS2 output from the timing controller 214 .

The switch SW2 electrically connects the node N1 and the node N2 according to the control signal CS2 output from the timing controller 214 so that energy stored in the target resonator can be transferred to the battery 220 . do. At this time, the switch SW1 is turned off according to the control signal CS1 output from the timing controller 214 .

Then, by connecting the switch SW2 , the energy stored in the target resonator may be transferred to the battery 220 in the form of current. A wireless power receiver that transfers energy stored in the target resonator to the load side as a current may be referred to as a current mode (CM) receiver.

The comparator 212 may output the difference between the voltage values of both ends of the capacitor C2 to the timing controller 214 . For example, the inverting input terminal (-) of the comparator 212 is connected to the node N0 to which one end of the capacitor C2 is connected, and the non-inverting input terminal (+) of the comparator 212 is the capacitor C2. is connected to the node N1 to which the other end is connected.

The comparator 213 may output a difference in voltage values between the nodes N1 and N2 to the timing controller 214 . For example, the inverting input terminal (-) of the comparator 213 is connected to the node N1 to which the other terminal of the capacitor C2 is connected, and the non-inverting input terminal (+) of the comparator 213 is a node on the load side. It is connected to (N2).

The timing controller 214 individually outputs the control signals CS1 and CS2 for controlling the switches SW1 and SW2 to the switches SW1 and SW2, respectively. The timing controller 214 may output the control signals CS1 and CS2 when the energy stored in the target resonator is equal to or greater than a predetermined level. Then, the energy transfer operation, that is, the transfer operation of the energy stored in the target resonator to the load is performed.

For example, the timing controller 214 determines whether the energy transfer condition is satisfied using the level of the voltage V2 stored in the capacitor C2, and when the energy transfer condition is satisfied, the node N1 and the node N2 A control signal CS2 for controlling the switch SW2 and a control signal CS1 for opening the switch SW1 are output to electrically connect the . That is, the timing controller 214 changes the level of the control signal CS2 of the disable level to the enable level so that the switch SW2 is turned on, and the control signal of the enable level so that the switch SW1 is turned off. The level of (CS1) can be changed to the disabled level. For example, if switch SW1 and switch SW2 are complementary transistors (eg, switch SW1 is a p-type transistor and switch SW2 is an n-type transistor), then switch SW1 and switch It is also possible to apply only one control signal to the gate at SW2.

Here, the energy transfer condition is whether the first period elapses after the voltage V2 stored in the capacitor C2 reaches the predetermined voltage level Vr, whether the current I2 flowing through the target resonator reaches the predetermined current level, Alternatively, the voltage V2 stored in the capacitor C2 may reach the first period increased or decreased by the timing controller 214 after reaching the predetermined voltage level Vr, and the like, but is not limited thereto.

In this embodiment, a case in which the control signals CS1 and CS2 are output according to the voltage level of the voltage V2 stored in the capacitor C2 using the comparator 212 will be described. When outputting the control signals CS1 and CS2 according to the current level of the current I2 , the wireless power receiver 200 may further include a current sensor, and the timing controller 214 controls the value detected from the current sensor. Accordingly, the control signals CS1 and CS2 for controlling the switches SW1 and SW2 may be generated and output.

The timing controller 214 may determine whether the energy transfer period has ended (ie, has elapsed), and control the switches SW1 and SW2 to stop the energy transfer operation when the energy transfer period ends. For example, the timing control unit 214 controls the switches SW1 and SW2 when the time from after changing the levels of the control signals CS1 and CS2 that controls the switches SW1 and SW2 reaches the energy transfer period, the switches ( Levels of the control signals CS1 and CS2 that control SW1 and SW2 are changed again. This energy transfer period may be stored in the storage unit 240 .

In this case, the timing controller 214 may adjust the time length of the energy transfer period according to the voltage difference between the node N1 and the node N2 . For example, if the node N2 voltage is lower than the node N1 voltage, the time length of the energy transfer period may be adjusted to increase. If the node N2 voltage is higher than the node N1 voltage, the time length of the energy transfer period may be adjusted to be reduced.

Also, the timing controller 214 may set an energy transfer condition according to the voltage V2 across the capacitor C2 . For example, if the voltage V2 across the capacitor C2 is negative (the voltage at the node N0 is lower than the voltage at the node N1), the timing controller 214 sets the voltage level of the energy transfer condition. elevate That is, after the voltage V2 stored in the capacitor C2 reaches the predetermined voltage level Vr, the energy transfer operation may be performed before reaching 0V. If the voltage V2 across the capacitor C2 is positive (the voltage at the node N0 is higher than the voltage at the node N1), the timing controller 214 lowers the voltage level of the energy transfer condition. That is, after the voltage V2 stored in the capacitor C2 reaches a predetermined voltage level Vr, the energy transfer operation may be performed after reaching 0V.

Next, a method of controlling a wireless receiving apparatus according to an embodiment will be described with reference to FIG. 4 .

Energy is transferred from the source resonator to the target resonator, and energy is accumulated in the target resonator. Then, the comparator 212 senses the voltage V2 across the capacitor C2 ( S100 ).

The timing controller 214 determines whether the energy transfer condition is satisfied by using the voltage V2 at both ends of the capacitor C2 ( S110 ). For example, the timing controller 214 determines, as the energy transfer condition, whether the time elapsed after the voltage V2 across the capacitor C2 reaches a predetermined voltage level Vr is a first period. The timing control unit 214 determines as an energy transfer condition whether the time elapsed after the voltage V2 across the capacitor C2 reaches a predetermined voltage level Vr is a first period increased or decreased by the timing control unit 214 . do. Alternatively, the timing controller 214 determines that the energy transfer condition is satisfied when the voltage V2 across the capacitor C2 reaches the voltage level set by the timing controller 214 after reaching the predetermined voltage level Vr. may judge.

If it is determined that the energy transfer condition is satisfied, the timing controller 214 performs an energy transfer operation ( S120 ). The timing controller 214 changes the level of the control signal CS2 of the disable level to the enable level so that the switch SW2 is turned on so that the energy of the target resonator can be transferred to the load side, and the switch SW1 The level of the control signal CS1 of the enable level may be changed to the disable level so that is turned off.

For example, as shown in FIG. 5 , the timing controller 214 is configured at a time point t1 when the first period elapses after the voltage V2 across the capacitor C2 reaches a predetermined voltage level Vr. , change the control signal CS1 to the disable level D, and change the control signal CS2 to the enable level E. In this case, the first period may be set to 1/m times of one period of the resonance frequency, and m is an integer. 5, m is 4.

Next, the timing controller 214 determines whether the energy transfer period IN2 ends ( S130 ). Here, the energy transfer period IN2 may be previously stored in the storage unit 240 or may be set by the timing controller 214 . The energy transfer period IN2 may be a period from the time when the energy transfer operation is started to the time when the energy transfer operation is stopped. That is, the timing controller 214 may determine whether the elapsed time from the time when the energy transfer operation is started reaches a pre-stored (or preset) energy transfer period IN2 .

If it is determined that the energy transfer period IN2 has ended, the timing controller 214 stops the energy transfer operation ( S140 ). The timing controller 214 changes the level of the control signal CS2 of the enable level to the disable level so that the switch SW2 is turned off so that the energy of the target resonator is no longer transferred to the load side, and the switch SW1 ) may be turned on, and the level of the control signal CS1 of the disable level may be changed to the enable level.

At this time, the timing controller 214 determines whether the voltage of the first node N1 is the same as the voltage of the second node N2 ( S150 ). This is to detect whether the current I2 flowing in the inductor L2 is 0 when the energy stored in the target resonator is transferred to the load side in the form of a current.

If the voltage of the first node N1 and the voltage of the second node N2 are not the same, the timing controller 214 adjusts the length of the energy transfer period ( S160 ). For example, if the node N2 voltage is lower than the node N1 voltage, the time length of the energy transfer period may be adjusted to increase. If the node N2 voltage is higher than the node N1 voltage, the time length of the energy transfer period may be adjusted to be reduced.

Steps S100 to S160 are repeated, and as shown in FIG. 5 , at a time t2 when the current I2 becomes 0, the timing controller 214 enables the switch SW2 to be turned off. The level of the control signal CS2 of the level may be changed to the disable level, and the level of the control signal CS1 of the disable level may be changed to the enable level so that the switch SW1 is turned on.

When the voltage of the first node N1 and the voltage of the second node N2 are the same, the timing controller 214 determines whether the voltage V2 across the capacitor C2 is 0V ( S170 ). The electric charge stored in the capacitor C2 flows by the current I2 flowing toward the load, and accordingly, the potential of the node N0 becomes lower than the ground potential 0V. Then, at the time when the energy transfer is finished ( t2 in FIG. 5 ), the voltage V2 across the capacitor C2 becomes a negative level, so that residual energy exists in the target resonator.

Therefore, when the voltage V2 across the capacitor C2 is not 0V so that such residual energy does not exist, the timing controller 214 sets the energy transfer condition ( S180 ). When the voltage V2 across the capacitor C2 is at a negative level (if the voltage at the node N0 is lower than the voltage at the node N1), the timing controller 214 decreases the first period of the energy transfer condition . When the voltage V2 across the capacitor C2 is at a positive level (the voltage at the node N0 is higher than the voltage at the node N1), the timing controller 214 increases the first period of the energy transfer condition. That is, after the voltage V2 stored in the capacitor C2 reaches the predetermined voltage level Vr, the first period until the start of the energy transfer operation may be increased or decreased. In this case, the first period may be increased or decreased by 1/n times of one period of the resonance frequency of the target resonator, where n is an integer. In this embodiment, it is assumed that n is 100.

If the energy transfer condition is adjusted in this way, the energy transfer period adjusted in step S160 needs to be adjusted again.

When the voltage V2 across the capacitor C2 is 0V, the timing controller 214 stores the energy transfer condition and the energy transfer period in the storage unit 240 ( S190 ).

For example, as shown in FIG. 6 , after the voltage V2 stored in the capacitor C2 reaches a predetermined voltage level Vr, the energy transfer operation is started at a time t11 before reaching 0V. can Then, the energy transfer operation is stopped at a time point t12 after the energy transfer period IN12 has elapsed. Since both the voltage V2 stored in the capacitor C2 and the current I2 flowing through the inductor L2 have a value of 0 at time t12, there may be no residual energy in the target resonator.

As described above, according to embodiments, the wireless power receiving apparatus has an effect of removing residual energy of the target resonator.

According to embodiments, there is an effect of minimizing power loss of the wireless power receiving device, thereby reducing power consumption of the wireless power transmitting device. In addition, there is an effect that the time consumed for charging the load of the wireless power receiver can also be reduced.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

Claims (22)

A power receiver for receiving power wirelessly transmitted from the wireless power transmitter;
A battery for receiving the current generated by the power from the power receiver, and
A timing controller configured to set a transfer start condition for starting the transfer of the current based on the residual energy of the power receiver when the transfer of the current is stopped
including,
The magnitude of the current when starting the transfer of the current is greater than zero, the wireless power receiver. According to claim 1,
The power receiver,
a resonator comprising an inductor and a capacitor, and
a first comparator outputting a voltage difference between both ends of the capacitor;
wherein the residual energy is the voltage difference across the capacitor,
wireless power receiver. 3. The method of claim 2,
The timing controller determines, as the transfer start condition, whether a time elapsed from when the voltage difference between both ends of the capacitor reaches a first voltage level is a first period, and when the transfer start condition is satisfied, transfer of the current to initiate,
wireless power receiver. 4. The method of claim 3,
The timing control unit sets the transfer start condition by decreasing the first period if the voltage difference between both ends of the capacitor is negative when the transfer of the current is stopped,
wireless power receiver. 4. The method of claim 3,
The timing control unit increases the first period when the voltage difference between both ends of the capacitor when stopping the transfer of the current is positive, to set the transfer start condition,
wireless power receiver. 6. The method according to claim 4 or 5,
The first period is increased or decreased by 1/n times of one period of the resonant frequency of the resonator, wherein n is an integer;
wireless power receiver. 4. The method of claim 3,
The first period is set to 1/m times of one period of the resonant frequency of the resonator, wherein m is an integer;
wireless power receiver. 3. The method of claim 2,
The power receiver,
a switch connected between the resonator and the battery; and
Further comprising a second comparator for outputting the voltage difference between both ends of the switch,
The timing control unit further sets a transfer stop condition for stopping the transfer of the current based on the voltage difference between both ends of the switch when the transfer of the current is stopped,
wireless power receiver. 9. The method of claim 8,
When the voltage difference between both ends of the switch is positive, the timing control unit sets the transfer stop condition so that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is increased.
wireless power receiver. 9. The method of claim 8,
When the voltage difference between both ends of the switch is negative, the timing control unit sets the transfer stop condition so that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is reduced.
wireless power receiver. 3. The method of claim 2,
The inductor and the capacitor are connected in series,
wireless power receiver. A method of receiving power from a wireless power transmitting apparatus performed by a wireless power receiving apparatus including a power receiving unit, a battery, and a timing control unit, the method comprising:
Receiving, by the power receiver, power wirelessly transmitted from the wireless power transmitter;
transmitting, by the power receiver, a current generated by the power to the battery under the control of the timing controller; and
setting, by the timing controller, a transfer start condition for starting the transfer of the current, based on the residual energy of the power receiver when the transfer of the current is stopped
including,
A method for receiving power wirelessly, wherein the magnitude of the current when initiating the transfer of the current is greater than zero. 13. The method of claim 12,
The power receiver,
a resonator comprising an inductor and a capacitor, and
a first comparator outputting a voltage difference between both ends of the capacitor;
wherein the residual energy is the voltage difference across the capacitor,
How to receive wireless power. 14. The method of claim 13,
The step of transferring the current generated by the electric power to the battery comprises:
determining, by the timing control unit, whether a time elapsed from after the voltage difference across the capacitor reaches a first voltage level is a first period as the transfer start condition; and
Comprising the step of controlling, by the timing controller, the power receiver to start the transfer of the current when the transfer start condition is satisfied,
How to receive wireless power. 15. The method of claim 14,
The step of setting the delivery start condition comprises:
If the voltage difference between both ends of the capacitor when the timing controller stops the transfer of the current is negative, reducing the first period to set the transfer start condition,
How to receive wireless power. 15. The method of claim 14,
The step of setting the delivery start condition comprises:
The timing control unit increases the first period if the voltage difference between the ends of the capacitor when stopping the transfer of the current is positive, including the step of setting the transfer start condition,
How to receive wireless power. 17. The method of claim 15 or 16,
The first period is increased or decreased by 1/n times of one period of the resonant frequency of the resonator, wherein n is an integer;
How to receive wireless power. 15. The method of claim 14,
The first period is set to 1/m times of one period of the resonant frequency of the resonator, wherein m is an integer;
How to receive wireless power. 14. The method of claim 13,
The power receiver,
a switch connected between the resonator and the battery; and
Further comprising a second comparator for outputting the voltage difference between both ends of the switch,
The method includes the steps of: based on a voltage difference between both ends of the switch when stopping the transfer of the current, setting a transfer stop condition for stopping the transfer of the current
A wireless power receiving method further comprising a. 20. The method of claim 19,
The step of setting the delivery stop condition comprises:
If the voltage difference between both ends of the switch is positive, setting the transfer stop condition so that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is increased.
How to receive wireless power. 20. The method of claim 19,
The step of setting the delivery stop condition comprises:
If the voltage difference between both ends of the switch is negative, setting a condition for stopping the transfer so that the length of time from when the transfer of the current is started to when the transfer of the current is stopped is reduced.
How to receive wireless power. A wireless power transmission device that wirelessly transmits power, and
The wireless power receiver according to any one of claims 1 to 5 and 7 to 11
A wireless power delivery system comprising a.

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