KR102392048B1 - Method and apparatus for power control in wireless power transmitting system - Google Patents

Abstract

The present invention relates to a method and apparatus for controlling power in a wireless power transmission system, comprising the steps of: transmitting wireless power to a wireless power receiving device located in a charging area through at least one primary coil; CEP carrying power control related information; Receiving a signal including a signal from the wireless power receiver through the primary coil, driving a CEP timer to check whether the CEP is received within a predetermined time, decoding a signal received through the primary coil Counting interrupts generated by It is characterized in that it is initialized when the CEP is received. According to the present invention, the wireless power transmitter can additionally determine whether the wireless power receiver is located in the charging area even if the CEP packet is not transmitted from the wireless power receiver for a certain period of time or longer, and continuously perform charging.

Description

Method and apparatus for controlling power in a wireless power transmission system

The present invention relates to wireless power transmission, and more particularly, to a method and apparatus for controlling power in a wireless power transmission system.

In general, in order to charge a portable terminal such as a mobile phone, a notebook computer, or a PDA, the portable terminal needs to receive electrical energy (or power) from an external charger. Such a portable terminal includes a battery cell for storing the supplied electrical energy and a circuit for charging and discharging the battery cell (supplying electrical energy to the portable terminal).

The electrical connection method between a charger and a battery cell for charging electric energy to a battery cell is to receive commercial power, convert it into voltage and current corresponding to the battery cell, and supply electric energy to the battery cell through the terminal of the battery cell. Includes terminal supply method.

This terminal supply method is accompanied by the use of a physical cable or wire. Therefore, when handling a lot of terminal-supply type equipment, many cables occupy a considerable work space, are difficult to organize, and are not good in appearance. In addition, the terminal supply method may cause problems such as an instantaneous discharge phenomenon due to a different potential difference between the terminals, burnout and fire caused by foreign substances, natural discharge, and deterioration of the life and performance of the battery pack.

Recently, in order to solve the above problems, a charging system (hereinafter referred to as a wireless power transmission system) and control methods using a wireless power transmission method have been proposed. The wireless power transmission method is also referred to as a contactless power transmission method or a non-contact power transmission method. The wireless power transmission system is composed of a wireless power transmission device for supplying electrical energy in a wireless power transmission method, and a wireless power reception device for charging a battery cell by receiving electrical energy wirelessly supplied from the wireless power transmission device.

In the terminal supply method, power is transmitted through the terminal connection between the charger and the terminal, and power transmission can be stopped when the terminal is short-circuited. On the other hand, in the wireless power transmission system, due to the characteristic of contactless charging, coupling (magnetic induction and / or magnetic resonance) is required, and the charger transmits power to the terminal through the magnetic field coupling. In this wireless power transmission system, when the charger performs wireless power transmission, the charger should be able to determine whether the terminal is removed from the charging area and stop power transmission. For example, the terminal transmits a packet such as a control error packet instructing the charger that the corresponding terminal is located in the charging area (or interface surface) to the charger, and the charger is For example, if the control error packet is not received for 1.8 seconds), it may be determined that the corresponding terminal has been removed from the charging area. However, when the terminal performs battery charging through wireless power reception, severe load fluctuations may occur in the terminal in some cases (hereinafter referred to as a light load state), which causes distortion in the packet transmitted from the terminal to the charger. can occur In this case, even when the terminal is located in the charging area, the charger determines that the terminal is removed from the charging area and stops power transmission.

It is an object of the present invention to provide a method and apparatus for controlling power in a wireless power transmission system.

Another technical object of the present invention is to provide a power control method and apparatus in consideration of a light load state of a wireless power receiving device in a wireless power transmission system.

Another technical object of the present invention is to propose an analysis standard for a case in which a wireless power transmission device receives a distorted signal in a wireless power transmission system.

Another technical problem of the present invention is to propose a criterion for detecting whether the wireless power receiving device is removed from the charging area in the wireless power transmission system.

According to an aspect of the present invention, there is provided a wireless power transmitter for performing power control. The wireless power transmitter is coupled with at least one secondary coil provided in the wireless power receiver positioned in the charging area to transmit wireless power. At least one primary coil (primary coil) , a communication unit that receives and decodes a signal including a control error packet (CEP) carrying power control related information from the wireless power receiver through the primary coil, and checks whether the CEP is received within a predetermined time and a control unit for driving a CEP timer for It controls wireless power transmission and interruption to the wireless power receiver through a coil, and initializes the CEP timer when the communication unit receives the CEP.

According to another aspect of the present invention, there is provided a wireless power transmission method by a wireless power transmission device that performs power control. The wireless power transmission method includes transmitting wireless power to a wireless power receiver located in a charging area through at least one primary coil, and transmitting a signal including a CEP carrying power control related information through the primary coil. Receiving from a wireless power receiver, driving a CEP timer to check whether the CEP is received within a predetermined time, counting interrupts generated in decoding a signal received through the primary coil, and the and controlling transmission and interruption of wireless power to the wireless power receiver through the primary coil based on a CEP timer and the interrupt count, wherein the CEP timer is initialized when the CEP is received.

According to the present invention, the wireless power transmitter can additionally determine whether the wireless power receiver is located in the charging area even if the CEP packet is not transmitted from the wireless power receiver for a certain period of time or longer, and continuously perform charging.

1 illustrates components of a wireless power transmission system according to an example of the present invention.
2 shows an example of a wireless power transmission procedure.
3 shows an example of a procedure for controlling the amount of transmitted power performed between the wireless power transmitter and the wireless power receiver.
4 is a flowchart illustrating an example of a method of performing power control by a wireless power transmitter in a wireless power transmission system according to the present invention.
5 is a flowchart illustrating another example of a method for performing power control by a wireless power transmitter in a wireless power transmission system according to the present invention.
6 is an example of a block diagram showing a wireless power transmitter and a wireless power receiver according to the present invention.

As used hereinafter, the term “wireless power” is used to mean any form of energy associated with an electric field, magnetic field, electromagnetic field, etc. transmitted from a transmitter to a receiver without the use of physical electromagnetic conductors. Wireless power may be referred to as a power signal, and may refer to an oscillating magnetic flux enclosed by a primary coil and a secondary coil. Power conversion in a system is described herein for wirelessly charging devices including, for example, mobile phones, codeless phones, iPods, MP3 players, headsets, and the like. In general, a basic principle of wireless energy transfer includes, for example, both a magnetic induction coupling method and a magnetic resonance coupling (ie, resonance induction) method. However, a variety of frequencies may be used, including frequencies that permit license-free operation at relatively high emission levels, for example below 135 kHz (LF) or at 13.56 MHz (HF).

1 illustrates components of a wireless power transmission system according to an example of the present invention.

Referring to FIG. 1 , a wireless power transmission system 100 includes a wireless power transmitter 110 and one wireless power receiver 150-1 or n wireless power receivers 150-1, ..., 150 -n) is included.

The wireless power transmitter 110 includes a primary core block. The primary core block may include a core and one or more primary coils 111 . The wireless power transmitter 110 may have any suitable shape, but one preferred configuration is a flat platform with a power transmission surface, each of which is placed on a charging area (eg, a charging pad) on or near the platform. Wireless power receivers 150-1, ..., 150-n may be located.

The wireless power receivers 150-1, ..., 150-n are detachable from the wireless power transmitter 110, and each wireless power receiver 150-1, ..., 150-n is When in the vicinity of the wireless power transmitter 110 is provided with a secondary core block (secondary core block) coupled with the electromagnetic field generated by the primary core block of the wireless power transmitter 110. The secondary core block may include a core and one or more secondary coils 151 .

The wireless power transmitter 110 transmits power to the wireless power receivers 150-1, ..., 150-n without direct electrical contact. In this case, the primary core block and the secondary core block are said to be magnetically inductively coupled or resonantly inductively coupled to each other. The primary coil or secondary coil may have any suitable shape, but may be, for example, a copper wire wound around a formation of high perameability such as ferrite or amorphous metal.

The wireless power receivers 150-1, ..., 150-n are usually connected to an external load (not shown. Here, also referred to as an actual load of the wireless power receiver), and wirelessly from the wireless power transmitter 110 The received power is supplied to an external load. For example, the wireless power receivers 150-1, ..., 150-n may deliver received power to an object that consumes or stores power, such as a portable electric or electronic device or a rechargeable battery cell or battery, respectively. there is.

2 shows an example of a wireless power transmission procedure.

Referring to FIG. 2 , the wireless power transmitter detects that the wireless power receiver is located in the charging area in a standby mode ( S200 ). Here, there may be various methods for the wireless power transmitter to detect the wireless power receiver, and the present invention is not limited to a specific method. For example, the wireless power transmitter periodically emits an analog ping of a specific frequency, and the wireless power receiver is located in the charging area based on the detected current, resonance shift, or capacitance change. can detect As another example, the wireless power transmitter periodically transmits a discovery signal, and when the wireless power receiver transmits a response signal based on the discovery signal, the wireless power receiver is located in the charging area based on the response signal can sense the As another example, when the wireless power transmitter periodically transmits a beacon, in response to this, the wireless power receiver transmits a searching signal or advertisement to the wireless power transmitter by transmitting wireless power. The device may detect the wireless power receiver.

The wireless power transmitter transmits an information request signal to the wireless power receiver as a preparation step for wireless power transmission (S210). Here, the information request signal may be a signal for requesting the ID and required power information of the wireless power receiver. For example, the information request signal may be transmitted in the form of a data packet message. As another example, the information request signal may be transmitted in the form of a digital ping according to a predefined standard between the wireless power transmitter and the wireless power receiver.

The wireless power receiver transmits ID and configuration information to the wireless power transmitter in response to the information request signal (S220). Here, the configuration information may include a maximum amount of power desired to be provided by the wireless power receiver.

The wireless power transmitter configures parameters for power transmission based on the ID and the configuration information and performs wireless power transmission to the wireless power receiver (S230). That is, the wireless power transmitter creates a power transmission contract based on the ID and the configuration information, and performs wireless power transmission to the wireless power receiver. The stage from which the wireless power transmitter starts transmitting wireless power to the wireless power receiver and stops it may be called a (wireless) power transfer phase.

The wireless power receiver may supply the received wireless power to an external load such as a battery.

The wireless power transmitter may monitor parameters for the power transmission, and when any one of the parameters exceeds a stated limit, the wireless power transmission may be aborted.

In addition, the wireless power transmission step of S230 may be terminated at the request of the wireless power receiver. For example, the wireless power receiver may transmit a signal requesting termination of wireless power transmission to the wireless power transmitter when the battery is fully charged.

On the other hand, after S230, the wireless power receiver continuously transmits a control error packet (CEP) to the wireless power transmitter periodically or aperiodically (S240-1, S240-2, S240-3). This is to control the amount of power transmitted from the wireless power transmitter to the wireless power receiver, that is, to perform power control. The power control procedure such as steps S240-1 to S240-3 may include the power control procedure according to the embodiments of FIGS. 3 to 5 .

3 shows an example of a procedure for controlling the amount of transmitted power performed between the wireless power transmitter and the wireless power receiver.

Referring to FIG. 3 , the wireless power receiver selects a desired control point ( S300 ). Here, the control point may include current and/or voltage, temperature of any one part of the wireless power receiver, and the like.

The wireless power receiver determines an actual control point based on the wireless power received from the wireless power transmitter (S310).

The wireless power receiver calculates a control error value using the desired control point and the actual control point (S320). For example, the control error value may be calculated based on a (relative) difference between a desired voltage (or current) and an actual voltage (or current).

The wireless power receiver generates a control error packet based on the control error value and transmits it to the wireless power transmitter (S330).

The wireless power transmitter sets a new operation point as needed based on the control error packet (S340). Here, the operating point may be, for example, at least one of an amplitude, a frequency, and a duty cycle of an AC voltage applied to the primary coil.

The wireless power transmitter performs wireless power transmission to the wireless power receiver based on the new operation point (S350). In this case, the wireless power transmitter may maintain the operation point until a new control error packet is received from the wireless power receiver.

Referring back to FIG. 2 , the wireless power transmitter is in the charging area if the control error packet is not received again as in S240-4 within a predetermined period T (eg, 1.8s) after the control error packet is received. It is considered that the wireless power receiver has been removed, and the wireless power transmission is stopped (S250). It is necessary to stop the wireless power transmission even when the user removes the wireless power receiver that receives wireless power from the charging area at any time in addition to exceeding the set limit of the above parameters and the battery is fully charged. because there is

However, when the wireless power receiver performs battery charging through wireless power reception, in the case of a light load condition inside the wireless power receiver and/or the battery, the packet transmitted from the wireless power receiver to the wireless power transmitter is distorted. This can happen. For example, while charging a battery connected to (or provided with) the wireless power receiver, in some cases, charging currents may change irregularly due to load instability. In this case, the It can distort packets. In this case, even when the wireless power receiver is located in the charging area, the wireless power transmitter determines that the wireless power receiver is removed from the charging area and stops the wireless power transmission. This causes unnecessary wireless power transmission interruption and delays battery charging.

4 is a flowchart illustrating an example of a method of performing power control by a wireless power transmitter in a wireless power transfer system according to the present invention. FIG. 4 corresponds to a subsequent procedure including step S230 of FIG. 2 .

Referring to FIG. 4 , the wireless power transmitter drives a control error packet (CEP) timer (S400). This is to check whether the wireless power transmitter receives the CEP within a predetermined time in the power transfer phase. The timer may be set to the predetermined period T described above with reference to FIG. 2 . In this case, for example, the timer may be set to 1.8s.

The wireless power transmitter initializes the interrupt count (S405). The wireless power transmitter drives a decoding algorithm to decode a message transmitted from the wireless power receiver, and when a received waveform is received from the wireless power receiver, an interrupt is generated for decoding. Specifically, when a waveform is applied to an interrupt port of a machine control unit (MCU) provided in the wireless power transmitter, a rising edge and a falling edge of the waveform regardless of a standing waveform or a non-standing waveform (eg, impulse noise) An interrupt occurs at a falling edge, and the interrupt count is incremented whenever an interrupt occurs.

When the interrupt count is initialized, the wireless power transmitter checks whether an interrupt occurs (S410). For example, when the wireless power transmitter receives a CEP packet, interrupts per one CEP packet may be counted about 66 times. One CEP packet includes a header, a message, and a checksum field composed of 1 byte each, and each field includes a start bit, a parity bit, Since a stop bit may be added, one CEP packet may include a total of 33 bits. In addition, since interrupts are generated at each rising edge and falling edge of the waveform, 66 interrupts can be generated for the 33 bits.

If an interrupt occurs in S410, the wireless power transmitter increments the interrupt count (S415), and checks whether the CEP timer has expired (or timed out) (S420). Here, the CEP timer has a value of T as described above.

If no interrupt occurs in S410, the wireless power transmitter checks whether the CEP timer has expired without increasing the interrupt count (S420).

If the CEP timer has not expired in S420, the wireless power transmitter checks whether there is a message packet received from the wireless power receiver (S425).

If there is no message packet received in S425, the wireless power transmitter returns to the procedure S410.

If there is a message packet received in S425 and the packet is a control error packet (CEP) (S430), the wireless power transmitter performs power control as necessary and initializes the CEP timer (S435), then again at S405 return to the procedure.

If there is a message packet received in S425 and the packet is an end power transfer packet (S440), the wireless power transmitter may end wireless power transmission (S445). Here, the end power transmission packet indicates, for example, a reason for requesting the end of the wireless power transmission, such as full charge, over temperature, over voltage, or over current. may contain information.

On the other hand, if the CEP timer expires in S420, the wireless power transmitter checks whether the interrupt count exceeds a reference value (S450). This is to determine whether the wireless power receiver is removed from the charging area based on the interrupt count value when the CEP timer expires. Here, the reference value may be set to, for example, 500. In this case, if the interrupt count value is greater than the reference value 500, the wireless power transmitter may determine that the wireless power receiver is still located in the charging area despite the expiration of the CEP timer.

If the interrupt count exceeds the reference value in S450, the wireless power transmitter determines that the wireless power receiver is located in the charging area, initializes the CEP timer (S455), and continues the wireless power transmission and (S460), the process returns to the above S405.

If the interrupt count does not exceed the reference value in S450, the wireless power transmitter considers that the wireless power receiver has been removed from the charging area and stops wireless power transmission (S465).

According to the above method, the wireless power transmitter additionally determines whether the wireless power receiver is located in the charging area through the interrupt count even if the CEP packet is not transmitted from the wireless power receiver for a certain period of time, and continuously performs charging. can In this case, severe load fluctuations in the wireless power receiver and/or battery temporarily occur, such as under a light load condition of the wireless power receiver, and distortion occurs in packets transmitted from the wireless power receiver to the wireless power transmitter. Even in this case, unnecessary interruption of wireless power transmission can be prevented and the battery can be quickly charged.

On the other hand, when the power control operation according to the present invention is performed by dividing the predetermined period T for the CEP timer into n equal sections and dividing each section into n equal sections, it can be expressed as follows.

5 is a flowchart illustrating another example of a method for performing power control by a wireless power transmitter in a wireless power transmission system according to the present invention.

Referring to FIG. 5 , the wireless power transmitter drives the CEP timer ( S500 ). The timer may be set to a value obtained by dividing the predetermined period T in FIG. 2 into n equal parts (ie, T/n). For example, when n=5 and T is 1.8s, the CEP timer may be set to 360ms.

The wireless power transmitter initializes the interrupt count (S505).

The wireless power transmitter checks whether an interrupt occurs (S510).

If an interrupt occurs in S510, the wireless power transmitter increments the interrupt count (S515) and checks whether the CEP timer has expired (or timed out) (S520). Here, the CEP timer has a T/n value as described above.

If no interrupt occurs in S510, the wireless power transmitter checks whether the CEP timer has expired without increasing the interrupt count (S520).

On the other hand, if the CEP timer expires in S520, the wireless power transmitter checks whether the interrupt count exceeds a reference value (S550). Here, the reference value may be set to, for example, 100.

If the interrupt count exceeds the reference value in S550, the wireless power transmitter determines that the wireless power receiver is located in the charging area, initializes the CEP timer (S555), and continues the wireless power transmission In the state of (S560), the process returns to the above S505.

If the interrupt count does not exceed the reference value in S550, the wireless power transmitter increases the CEP decoding failure count (S562). Here, the CEP decoding failure count indicates the number of consecutive sections in which CEP decoding fails and the interrupt is equal to or less than the reference value among the n sections described above. That is, when CEP decoding fails for all of the n sections and an interrupt is detected to be less than or equal to a reference value, it can be seen that the wireless power transmitter has not received the CEP for the predetermined period T, and in this case, the wireless power receiver It can be seen that is removed from the filling region.

The wireless power transmitter checks whether the CEP decoding failure count is greater than or equal to the n (S563).

If the CEP decoding failure count is smaller than the n in S563, the wireless power transmitter initializes the CEP timer (S555), and returns to the S505 procedure.

If, in S563, the CEP decoding failure count is greater than or equal to n, the wireless power transmitter considers that the wireless power receiver has been removed from the charging area and stops wireless power transmission (S565).

Since the remaining steps S525, S530, S535, S540, and S545 are the same as the procedures in FIG. 4 , a detailed description thereof will be omitted.

6 is an example of a block diagram showing a wireless power transmitter and a wireless power receiver according to the present invention.

Referring to FIG. 6 , the wireless power transmitter 600 is connected to at least one primary coil 605 and the primary coil 605 to apply electric driving signals to the primary coil 605 to generate an electromagnetic field. and a power conversion unit 610 , a communication unit 620 , and a control unit 630 .

The wireless power transmitter 600 may have any suitable shape, but one preferred configuration is a flat platform with a power transmission surface, each wireless power receiver 650 in a charging area on or near the platform. can be placed

The power conversion unit 610 may be a half-bridge inverter or a full bridge inverter. The power conversion unit 610 may control the frequency, duty cycle, amplitude, etc. of the electric driving signal applied to the primary coil 605 through switching.

The communication unit 620 controls communication between the wireless power transmitter 600 and the wireless power receiver 650 . For example, the communication unit 620 may communicate with the wireless power receiver 650 through the primary coil 605 . As another example, the communication unit 620 may communicate with the wireless power receiver 650 through separate radio frequency (RF) communication means respectively provided in the communication unit 620 and the communication unit 680 .

The communication unit 620 may receive an ID, configuration information, CEP, or an end power transfer packet from the wireless power receiver 650 .

The control unit 630 generates a control signal for power control based on the ID, the configuration information, the CEP, and the end power transmission packet, and transmits the control signal to the power conversion unit 610 .

The control unit 630 may perform a control operation necessary to implement the present invention as described above.

The control unit 630 may initialize and drive the CEP timer. Here, the CEP timer may be set to a reference time T or a T/n value.

The control unit 630 may initialize and measure an interrupt count relating to an interrupt that occurs when the communication unit 630 decodes a received waveform.

The control unit 630 performs power control according to the present invention based on the CEP timer and the interrupt count.

For example, when the CEP timer (eg, T) expires, the control unit 630 compares the interrupt count at the time the CEP timer expires with a reference value, and when the interrupt count is greater than the reference value, the Despite the expiration of the CEP timer, the wireless power receiver 650 is still considered to be located in the charging area of the wireless power transmitter 600 , and wireless power transmission through the primary coil 605 can be continued.

As another example, when the interrupt count is not greater than the reference value, the control unit 630 determines that the wireless power receiver 650 is removed from the charging area according to the expiration of the CEP timer, and the primary coil 605 ) to stop wireless power transmission.

As another example, when the CEP timer (eg, T/n) expires, the control unit 630 compares the interrupt count at the time the CEP timer expires with a reference value, and the interrupt count is greater than the reference value. case, increase the CEP decoding failure count, and if the CEP decoding failure count is greater than or equal to n, the wireless power receiver 650 is considered to be removed from the charging area, and wireless power transmission through the primary coil 605 can be stopped

The wireless power receiver 650 is detachable from the wireless power transmitter 600, and when the wireless power receiver 650 is in the charging area of the wireless power transmitter 600, by the wireless power transmitter 600 It has at least one secondary coil 655 coupled to the generated electromagnetic field. In this way, power may be transferred from the wireless power transmitter 600 to the wireless power receiver 650 without direct electrical contact. The wireless power receiver includes a load 670 , a power pick-up unit 660 that is connected to the secondary coil 655 to collect power and supplies power to the load 670 , and a communication unit 680 . ), and a control unit 690 .

The communication unit 680 controls communication between the wireless power transmitter 600 and the wireless power receiver 650 . For example, the communication unit 680 may communicate with the wireless power transmitter 600 through the secondary coil 605 . As another example, the communication unit 620 and the communication unit 680 may each include a separate RF communication means, and the communication unit 680 communicates with the wireless power transmitter 600 through the RF communication means. You may.

The communication unit 680 may transmit the ID, configuration information, CEP, or end power transfer packet of the wireless power receiver 650 to the wireless power transmitter 600 .

The control unit 690 performs a series of controls to allow the wireless power receiver 650 to receive a suitable level of wireless power.

All of the above-described functions may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), etc. according to software or program code coded to perform the functions. The design, development and implementation of the above code will be apparent to those skilled in the art based on the description of the present invention.

Although the present invention has been described with reference to the embodiments, those of ordinary skill in the art can variously modify and change the present invention within the scope without departing from the technical spirit and scope of the present invention. you will understand Therefore, the present invention is not limited to the above-described embodiments, and it will be said that all embodiments within the scope of the following claims are included.

Claims (16)

A wireless power transmission device comprising:
at least one primary coil configured to transmit wireless power to the wireless power receiver;
a communication unit configured to receive control data from the wireless power receiver through the primary coil; and
A control unit comprising:
control wireless power transmission to the wireless power receiver based at least in part on the control data received from the wireless power receiver;
When the control data includes a control error packet (CEP) including a control error value, set an operation point for the wireless power transmission through the primary coil based at least in part on the control error value the control unit configured to
Including, a wireless power transmission device. According to claim 1,
The control error value is received in the CEP from the wireless power receiver, the wireless power transmitter. 3. The method of claim 2,
The CEP is received through a signal received from the wireless power receiver,
the control unit is further configured to initialize a CEP timer when the communication unit receives the CEP and to count interrupts occurring in decoding the received signal;
The control unit is further configured to stop or control the wireless power transmission to the wireless power receiver based on the count of the CEP timer and the interrupt. 4. The method of claim 3,
The CEP timer indicates whether the CEP is received within a predetermined time, the wireless power transmitter. 4. The method of claim 3,
the control unit stops the wireless power transmission when the CEP timer expires and the count of the interrupt is not greater than a reference value;
when the CEP timer expires and the count of the interrupt is greater than a reference value, the control unit continues the wireless power transmission and initializes the CEP timer;
and the control unit increments the CEP decoding failure count when the CEP timer expires and the count of the interrupt is not greater than a reference value. According to claim 1,
The control unit is also
When the control data includes an end power transmission packet, the wireless power transmission device is configured to terminate the wireless power transmission through the primary coil. 7. The method of claim 6,
The end power transmission packet will include information indicating the reason for requesting the end of the wireless power transmission, the wireless power transmission device. 8. The method of claim 7,
The reason will include at least one of buffering, overheating, overvoltage or overcurrent, the wireless power transmission device. A method performed by a wireless power transmission device, comprising:
transmitting wireless power to a wireless power receiver through at least one primary coil;
receiving control data from the wireless power receiver through the primary coil;
controlling wireless power transmission to the wireless power receiver based at least in part on the control data received from the wireless power receiver; and
setting an operation point for the wireless power transmission through the primary coil based at least in part on the control error value when the control data includes a control error packet (CEP) including a control error value;
A method comprising 10. The method of claim 9,
wherein the control error value is received at the CEP from the wireless powered device. 11. The method of claim 10,
The CEP is received through a signal received from the wireless power receiver,
The method is
when the wireless power receiver receives the CEP, initializing a CEP timer and counting interrupts generated in decoding the received signal; and
Stopping or controlling the wireless power transmission to the wireless power receiver based on the count of the CEP timer and the interrupt
A method further comprising: 12. The method of claim 11,
wherein the CEP timer indicates whether the CEP is received within a certain amount of time. 12. The method of claim 11,
The step of stopping or controlling the wireless power transmission comprises:
stopping the wireless power transmission when the CEP timer expires and the count of the interrupt is not greater than a reference value;
continuing the wireless power transmission and initializing the CEP timer when the CEP timer expires and the count of the interrupt is greater than a reference value; and
incrementing the CEP decoding failure count when the CEP timer expires and the count of the interrupt is not greater than a reference value
A method comprising 10. The method of claim 9,
terminating the wireless power transmission through the primary coil when the control data includes an end power transmission packet
A method further comprising: 15. The method of claim 14,
The method of claim 1, wherein the termination power transmission packet includes information indicating a reason for requesting termination of the wireless power transmission. 16. The method of claim 15,
The method of claim 1, wherein the reason comprises at least one of buffering, overheating, overvoltage or overcurrent.

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