KR20120133080A - Method for controlling received power in wireless power receiving device and wireless power receiving device thereof - Google Patents

Abstract

PURPOSE: A power reception control method in a wireless power reception device, and the wireless power reception device applying the same are provided to stably operates an electronic device connected to the wireless power reception device by softly lowering a charging voltage to a set voltage and set current when a load connection event is occurred. CONSTITUTION: A wireless power transmission device includes a primary side core(110), a transmission controller(120), and an AC/DC converter(130). The primary side core includes a first subsidiary coil(111) and a second subsidiary coil(112). The AC/DC inverter converts an AC power supply into a DC power supply of a predetermined voltage. A wireless power reception device(200) includes a secondary side core(210), a rectifier(220), a battery cell module(230), and a reception controller(240). The secondary side core receives a wireless power signal transmitted from the primary side core of the wireless power transmission device. [Reference numerals] (121) Object sensor; (122) Central controller; (123) Switching controller; (124) Driver; (125) Serial resonant converter; (130) AC/DC converter; (220) Rectifier; (230) Battery cell module; (240) Reception controller

Description

TECHNICAL FIELD OF CONTROLLING RECEIVED POWER IN WIRELESS POWER RECEIVING DEVICE AND WIRELESS POWER RECEIVING DEVICE THEREOF

The present invention relates to a method for controlling power reception in a wireless power receiver and a wireless power receiver using the same.

2. Description of the Related Art Generally, a battery pack is a battery pack for supplying electric power for operating a portable terminal (a mobile phone, a PDA or the like) in a state of being supplied with electric power (electric energy) from an external charger, And a circuit for charging and discharging the battery cell (supplying electric energy to the portable terminal).

In the electrical connection method of the charger and the battery pack for charging the electrical energy to the battery pack used in the portable terminal, the commercial power is supplied to convert the voltage and current corresponding to the battery pack to the battery pack through the terminals of the battery pack. There is a terminal supply method for supplying electrical energy.

However, when power is supplied by such a terminal supply method, when the charger and the battery pack are brought into contact with or separated from each other, the terminals (the terminals of the battery pack and the terminals of the charger) of the two sides have different potential differences, There was a problem.

Particularly, when foreign substances are accumulated on the terminals on both sides due to the instantaneous discharge phenomenon, there is a possibility of fire or the like.

In addition, there is a problem in that electric energy charged in the battery pack due to moisture or the like is naturally discharged to the outside through the terminal of the battery pack, and the life and performance of the battery pack are deteriorated.

Recently, a non-contact charging system and a control method using a wireless power transmission method have been proposed in order to solve the above problems.

In such a wireless power transmission system, there have been efforts to improve wireless power efficiency with stable power reception.

According to the present invention, when the load is connected to the rectifying unit as the wireless charging is started, the charging voltage is suddenly lowered, thereby preventing the wireless power receiver itself from being shut down, thereby stably charging the battery.

In order to solve the above problems, a method for controlling power reception in a wireless power receiver according to an embodiment of the present invention includes: receiving a power signal from a wireless power transmitter and applying a charging voltage of a rectifier of the wireless power receiver; And when the charge start signal is generated, controlling the load current of the first set current smaller than the set charge current to flow to the load.

Here, the power receiving control method, after the first set current flows a predetermined time, controlling the load current of the second set current larger than the first set current and smaller than the set charging current flows to the load It may further include.

Here, the power reception control method may further include controlling the load current to gradually set the charging current.

Here, the load is a battery, and the power reception control method, after the load current is equal to the set charging current, and transmits a battery status information signal including the status information of the battery to the wireless power transmission device. It may further comprise a step.

Here, after the load current becomes equal to the set charging current, the step of transmitting a battery state information signal including state information of the battery to the wireless power transmitter may include a short range communication module of the wireless power receiver. The method may include transmitting the battery status information signal to the wireless power transmitter.

Here, after the load current is equal to the set charging current, the step of transmitting a battery state information signal including the state information of the battery to the wireless power transmitter, the secondary core of the wireless power receiver The method may include transmitting the battery status information signal to the wireless power transmitter.

Here, the power reception control method, measuring the charging voltage of the rectifier in a first period; And detecting the charging voltage of the rectifying unit in a second period shorter than the first period, while the load is connected to the rectifying unit according to the charging start signal.

Here, the first period may be 5 times to 20 times the second period.

The power reception control method may include transmitting an ID signal of the wireless power receiver to a wireless power transmitter; And receiving the wireless power signal based on the ID signal and rectifying the wireless power signal to the DC power by the rectifying unit to apply the charging voltage.

Another embodiment of the present invention provides a wireless power receiver, comprising: a secondary core configured to receive a wireless power signal from a primary core of the wireless power transmitter; A rectifier for rectifying the wireless power signal received from the secondary side core; When the charging start signal is generated after the charging signal is applied after receiving the power signal from the wireless power transmitter, the control unit controls the rectifying unit so that the load current of the first set current smaller than the set charging current flows to the load. It may include a control unit.

Here, the reception control unit may control the load current of the second set current larger than the first set current and smaller than the set charging current to flow to the load after the first set current flows for a predetermined time.

Here, the reception controller may control the charging voltage to be the set voltage while the load current becomes the set charging current.

Here, after the load is a battery and the load current becomes equal to the set charging current, the reception controller may transmit a battery state information signal including state information of the battery to the wireless power transmitter.

Here, the reception control unit measures the charging voltage of the rectifying unit in a first period, and when the load is connected to the rectifying unit according to the charging start signal, senses the charging voltage of the rectifying unit in a second period shorter than the first period. can do.

Here, the reception controller transmits an ID signal of the wireless power receiver to a wireless power transmitter, receives a wireless power signal based on the ID signal, rectifies it to DC power from the rectifier, and applies the charging voltage. Can be.

According to the present invention having the above-described configuration, when a load connection event such as a charging start signal occurs in the wireless power receiver, the charging voltage is suddenly lowered, thereby preventing the wireless power charging from being shut down. .

In addition, according to the present invention having the above-described configuration, when the load connection event occurs, by softening down to the set voltage and the set current, it is possible to stably charge the battery or to stably operate the electronic device connected to the wireless power receiver. .

1 is a block diagram of a wireless power transmission system according to an embodiment of the present invention.
2 is a flowchart illustrating a method of controlling a wireless power signal in a wireless power transmission system according to an embodiment of the present invention.
3 is a view showing a change in value over time of the current flowing to the battery when the method for controlling a wireless power signal in the wireless power receiver according to an embodiment of the present invention.
4 is a view for explaining the effect of the wireless power signal control method applied in the wireless power receiver according to an embodiment of the present invention.

Hereinafter, a method of controlling a wireless power signal in a wireless power transmitter and a wireless power transmitter using the same will be described in more detail with reference to the accompanying drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

1 is a block diagram of a wireless power transmission system according to an embodiment of the present invention. As shown in the figure, a wireless power transmission system according to an embodiment of the present invention includes a wireless power transmission apparatus 100 and a wireless power reception apparatus 200. That is, when the wireless power transmitter 100 transmits the wireless power signal to the wireless power receiver 200 by the electromagnetic induction method, the wireless power receiver 200 that receives the power signal receives the wireless power signal. The battery is charged with power, or power is supplied to the electronic device connected to the wireless power receiver 200.

Hereinafter, the configurations of the wireless power transmitter 100 and the wireless power receiver 200 will be described.

A wireless power transmission apparatus 100, which is a temporary example of the present invention, includes a primary side 110, a transmission control unit 120, and an AC / DC converter 130. Here, the primary core 110 (primary coil) is a device for transmitting a power signal to the secondary core 210 of the power receiver 200 in an electromagnetic induction manner, and in this embodiment, two coils (that is, The first sub coil 111 and the second sub coil 112 may be applied.

Referring back to FIG. 1, the transmission controller 120 that controls the primary core 110 includes an object detector 121, a central controller 122, a switching controller 123, a driver driver 124, and a serial device. Resonant converter 125 may include.

The object detector 121 detects a load change of the primary core 110, which is the primary coil, and determines whether the load change is caused by the wireless power receiver 200 (that is, the ID checker). It has a function as), and performs the function of filtering and processing the state of charge signal transmitted from the wireless power receiver 200. That is, when the ID signal, which is a response signal of the ID call signal transmitted through the primary side core 110, is received, the ID signal is filtered and processed, and a charge state signal including information on the battery cell or the charge voltage is received When. And filters and processes them.

The central controller 122 analyzes the ID signal received from the primary core 110 and transmits the wireless power signal through the primary core 110 to the central controller 122. [ And transmits the power signal to the driving driver 124. Further, when the charging state signal is received from the primary side core to be described later, it controls the driving driver 124 to change the wireless power signal based on the charging state signal.

The switching controller 123 controls the switching operation of the switch between the series resonant converter 125 and the first sub coil 111 and the second sub coil 112. In the present invention, two sub-coils are used, but the present invention is not limited thereto, and includes a case where one coil is applied. When one coil is applied, the switching controller 123 becomes unnecessary.

The driving driver 124 controls the operation of the series resonant converter 125 through the control of the central controller 122.

The series resonant converter 125 generates a power supply for generating a power signal to be delivered by the drive driver 124 and supplies the generated power to the primary core 110. In other words, when the central control unit 122 transmits a power control signal for sending a power signal having a required power value to the driving driver 124, the driving driver 124 generates a serial The series resonant converter 125 controls the operation of the resonant converter 125 so that the outgoing power supply corresponding to the power value required by the control of the drive driver 124 is applied to the primary core 110, So that the wireless power signal of the required intensity is transmitted.

In addition, the series resonant converter 125 may transmit the first object detection signal and the second object detection signal through the first sub coil 111 and the second sub coil 112, respectively, under the control of the driving driver 124. It supplies the power to generate.

The AC / DC inverter 130 is a device for changing an AC power source of 220V or 110V into a DC power source having a predetermined voltage. As described above, the output voltage value is changed by the control of the central control unit 122.

In addition, the wireless power receiver 200 receiving the power signal and receiving power includes a secondary side core 210 for generating induced power by the transmitted power signal, a rectifier 220 for rectifying the induced power, The battery cell module 230 is charged with rectified power, and the secondary side core 210, the rectifier 220, and a reception controller 240 for controlling the battery cell module.

The secondary core 210 is a component for receiving the wireless power signal transmitted from the primary side core of the wireless power transmission apparatus 100.

The rectifier 220 rectifies the radio power received from the secondary core to a DC voltage and maintains the charged state until the charging starts.

Under the control of the reception control unit 240, the battery cell module 230 becomes a charging object to be charged through the DC power source from the rectifying unit 220. Instead of the battery cell module 230 may be an electronic device such as PMP, MP3, mobile phone. Meanwhile, the battery cell module 230 includes a protection circuit such as an over-voltage and over-current prevention circuit, a temperature sensing circuit, etc., and a charge management module for collecting and processing information on the charge state of the battery cell .

The reception controller 240 is a component that controls the current of the power source charged in the rectifier 220 so that a proper current flows through the battery cell module 230. A detailed operation of the reception controller 240 will be described in more detail with reference to FIG. 2.

These operations will be described in more detail with reference to the flowchart of FIG. 2.

2 is a flowchart illustrating a method of controlling a wireless power signal in a wireless power transmission system according to an embodiment of the present invention.

As shown, first, the wireless power transmitter 100 transmits an ID call signal to the wireless power receiver 200 (S1). At this time, the ID call signal may be transmitted through the primary core 110, or a short-range communication module may be used. That is, RFID, Bluetooth, Zigbee, etc. may be used.

The wireless power receiver 200 receiving the ID call signal transmits the ID signal to the wireless power transmitter 100 through the secondary core 210 or the short range communication module (S3). The central control unit 122 of the wireless power transmitter 100 receiving the ID signal controls the driving driver 124 to transmit a wireless power signal (power signal) (S5). The charging voltage is applied to the rectifier 220 of the wireless power receiver 100 receiving the power signal through the secondary side core 210 (S7). At this time, the charging voltage becomes larger than the set voltage (ie, the voltage set for charging the battery). As the charging voltage is set larger than the set voltage, the charging voltage of the rectifier at the load connection is lower than the shutdown voltage (the voltage at which the charging voltage of the rectifier 220 is lower than the set voltage to shut down the entire power receiver to protect the circuit). Can prevent losing.

When a load such as a battery cell is connected to the rectifying unit by a charge start signal, the reception controller 240 initially controls the load current Ic such that the load current Ic becomes a first set current smaller than the set charging current. (S9, S11). The first set current at this time gradually increases with time, and when the charging voltage is stabilized, the load current may be controlled to be the set charging current or may be stepped up at predetermined time intervals. That is, the reception controller 240 may control the load current such that the second set current larger than the first set current and smaller than the set charging current becomes the load current after the first set current has passed a predetermined time. (S13). Here, the set charging current means a current flowing in the battery cell when the battery cell is normally charged. The predetermined charging voltage is applied to the load by the set charging current, and thus charging is normally performed. Then, the charging status signal is transmitted to the wireless power transmitter in the first cycle (S17).

While the charging is started by the charging start signal and the load current is stepped up, the charging state signal is transmitted in the second period shorter than the first period (S19). Here, the charge state signal may include one of state information of the battery cell and voltage information of the rectifier.

Here, the second period may be 1/5 to 1/20 of the first period. That is, the second period must be less than 1/5 of the first period to achieve soft down of the voltage, which is the object of the present invention. If it is smaller than 1/20 of the first period, it is inefficient in terms of energy efficiency. That is, compared to the first period of 150-250ms, the second period may be 10-50ms.

When the charging voltage of the rectifier 220 is measured in the second cycle and the charge status signal including the charging state information of the rectifier 220 is transmitted to the wireless power transmitter 100 in the second cycle, the wireless power transmitter ( Based on this, the changed power signal is transmitted to the wireless power receiver 200 (S13). That is, the power signal is changed more often (5 to 20 times). Accordingly, the charging voltage of the rectifier 220 is softened down.

When the charging voltage of the rectifier 220 is stabilized as described above, the voltage of the rectifier 220 is measured again in the first cycle, and the charging state signal is transmitted to the wireless power transmitter 100 in the first cycle.

According to the present invention having the above-described configuration, when a load connection event such as a charging start signal occurs in the wireless power receiver, the charging voltage is suddenly lowered to prevent the wireless power receiver from being shut down. do.

3 is a diagram illustrating a change in a value over time of a current flowing to a battery when a method of controlling a wireless power signal in a wireless power receiver according to an embodiment of the present invention is applied.

In FIG. 3, the vertical axis represents load current flowing to the battery cell module, and the horizontal axis represents time. Here, 100 mA is the first set current and 400 mA is the second set current. 700mA is the set charge current.

(A) is a current line according to an embodiment of the present invention, (B) is a voltage line of another embodiment of the present invention.

In the 0-A section, the connection to the battery cell 230 is short-circuited before the charge start signal is generated. In the AB section, the charge start signal is generated and the connection to the battery cell 230 is made, so that the load current is transmitted to the battery cell 230. (Ic) represents a period in which the flow, B and subsequent sections represent a state in which the charging voltage is stabilized and the battery cell module 230 is normally charged.

As shown in Fig. 2A, the load current reaches the set charging current in a manner of step-up in the AB section, and according to the line 2B, the load current sequentially sets the charging current in the AB section. To reach. In this manner, if the current control is performed at the start of the charging signal, the charging voltage may be softly down when the load connection event occurs to further prevent the wireless power charging system from being shut down.

The effect thereof will be described in more detail with reference to FIG. 4.

4 is a view for explaining the effect of the wireless power signal control method applied in the wireless power receiver according to an embodiment of the present invention.

In FIG. 4, the vertical axis represents charging voltage of the rectifier and the horizontal axis represents time. Where 5V is the set voltage, 3V is the shutdown voltage, and 7V is the initial charge voltage.

(A) is a voltage line according to an embodiment of the present invention, (B) is a voltage line of the comparative example.

In the 0-A section, the voltage of the rectifier of the wireless power receiver receiving the wireless power signal is indicated. The AB section is a period from when the charging start signal is generated until the charging voltage is stabilized. It is stabilized and shows a state in which the battery cell module 230 is normally charged.

According to the present embodiment, it can be seen that the charging voltage of the rectifier 220 softens down in the A-B period. That is, in the AB section, when the load current is increased in time or in a step-up manner as in the (A) or (B) line of FIG. 3, the charging voltage is softened down as in the (A) line of FIG. 4. The charging voltage of the rectifier does not go down until the shutdown voltage.

On the other hand, in the (b) line of the comparative example, since there is no current control in the receiver, the charging voltage of the rectifying unit 220 at the time of the charging start signal is drastically lowered to near the shutdown voltage, so that the power transmission receiving apparatus 200 The risk of shutting down the whole is increased.

On the other hand, when the charging start signal is added to transmit the charging state signal in the second period, the charging voltage of the rectifier 220 is further softened down, it is possible to better prevent the shutdown phenomenon of the power receiver.

According to the present invention having the above-described configuration, when a load connection event such as a charging start signal occurs in the wireless power receiver, the charging voltage is suddenly lowered to prevent the wireless power charging system from shutting down. do.

In addition, according to the present invention having the above-described configuration, when the load connection event occurs, by softening down to the set voltage and the set current, it is possible to stably charge the battery or to stably operate the electronic device connected to the wireless power receiver. .

The wireless power signal control method and the wireless power transmission apparatus using the same in the above-described wireless power transmission apparatus may not be limitedly applied to the configuration and method of the above-described embodiments, and the embodiments may be modified in various ways. All or part of each of the embodiments may be configured to be selectively combined to make it possible.

100: Wireless power transmission device
111: first sub coil
112: second sub coil
120:
121: object detection unit
122:
123:
124 drive driver
125: Series resonant converter
130: AC / DC converter
200: Wireless power receiving device
210: secondary side core
220: rectification part
230: battery cell module
240:

Claims (15)

Receiving a power signal from the wireless power transmitter and applying a charging voltage to a rectifier of the wireless power receiver; And
And when the charge start signal is generated, controlling the load current of the first set current smaller than the set charge current to flow to the load.
The method of claim 1,
And controlling a load current of a second set current larger than the first set current and smaller than the set charging current to flow to the load after the first set current has passed for a predetermined time. Power reception control method.
The method of claim 1,
And controlling the load current to gradually become the set charging current.
The method of claim 1,
The load is a battery,
After the load current becomes equal to the set charging current, transmitting a battery state information signal including state information of the battery to the wireless power transmitter, the power reception control in the wireless power receiver. Way.
The method of claim 4, wherein
After the load current becomes equal to the set charging current, transmitting a battery state information signal including state information of the battery to the wireless power transmitter,
And transmitting the battery status information signal to the wireless power transmitter through a short range communication module of the wireless power receiver.
The method of claim 4, wherein
After the load current becomes equal to the set charging current, transmitting a battery state information signal including state information of the battery to the wireless power transmitter,
And transmitting the battery status information signal to the wireless power transmitter via the secondary core of the wireless power receiver.
The method of claim 1,
Measuring the charging voltage of the rectifier at a first period; And
And connecting the load to the rectifier according to the charging start signal, and detecting a charging voltage of the rectifier in a second period shorter than the first period.
The method of claim 7, wherein
And the first period is 5 to 20 times greater than the second period.
The method of claim 1,
Transmitting an ID signal of the wireless power receiver to a wireless power transmitter; And
And receiving the wireless power signal based on the ID signal and rectifying the wireless power signal to a DC power by the rectifying unit to apply the charging voltage.
A secondary side core configured to receive a wireless power signal from a primary side core of the wireless power transfer apparatus;
A rectifier for rectifying the wireless power signal received from the secondary side core; And
When the charging start signal is generated after the charging signal is applied after receiving the power signal from the wireless power transmitter, the control unit controls the rectifying unit so that the load current of the first set current smaller than the set charging current flows to the load. Wireless control device including a control unit.
11. The method of claim 10,
The reception control unit,
And after the first set current has passed for a predetermined time, a load current of a second set current larger than the first set current and smaller than the set charging current flows to the load.
11. The method of claim 10,
The reception control unit,
And control the load current to be gradually set to the set charging current.
11. The method of claim 10,
The load is a battery,
The reception control unit,
And after the load current becomes equal to the set charging current, transmitting a battery state information signal including state information of the battery to the wireless power transmitter.
11. The method of claim 10,
The reception control unit,
While measuring the charging voltage of the rectifier in a first period, when the load is connected to the rectifier in accordance with the charge start signal, detecting the charging voltage of the rectifier in a second period shorter than the first period.
11. The method of claim 10,
The reception control unit,
And transmitting the ID signal of the wireless power receiver to the wireless power transmitter, receiving the wireless power signal based on the ID signal, rectifying the ID signal from the rectifier to DC power, and applying the charging voltage.

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