KR102272360B1 - Apparatus for receiving wireless power - Google Patents

Abstract

A wireless power receiving apparatus is provided. A wireless power receiving apparatus according to an embodiment of the present invention includes: a power receiving unit for wirelessly receiving power from the outside; a rectifying unit having a bridge rectifying circuit and converting an AC voltage input from the power receiving unit into a DC voltage; a switch unit connected to the bridge rectifying circuit; and a controller that turns on the switch unit when the converted DC voltage exceeds a threshold voltage, and turns off the switch unit when the converted DC voltage is equal to or less than a threshold voltage.

Description

Wireless power receiving device {Apparatus for receiving wireless power}

The present invention relates to a wireless power receiver, and more particularly, to a wireless power receiver that converts an AC voltage wirelessly received into a DC voltage.

Traditionally, instead of a method of supplying electrical energy to wireless power receivers by wire, a method of supplying electrical energy wirelessly without contact is recently used. The wireless power receiver wirelessly receiving energy may be directly driven by the received wireless power, or may charge a battery using the received wireless power and be driven by the charged power.

1 is a circuit diagram illustrating a conventional wireless power receiver, and FIG. 2 is a graph illustrating an AC voltage received by the conventional wireless power receiver.

Also, FIG. 3 is an operation diagram of a conventional wireless power receiver, and FIG. 4 is a graph illustrating a voltage rectified by the conventional wireless power receiver.

Referring to FIG. 1 , the conventional wireless power receiver 10 includes a power receiver 110 , a rectifier 120 , a converter 130 , and a load 140 .

The power receiver 110 receives power transmitted from the wireless power transmitter. At this time, the power received by the power receiver 110 is a sinusoidal AC voltage as shown in FIG. 2 .

The rectifier 120 includes first to fourth diodes D1 , D2 , D3 , and D4 to convert the power received from the power receiver 110 into a DC voltage.

At this time, referring to FIG. 3 , in the AC power received from the power receiver 110, only diodes D1 and D4 are forward biased for the first half cycle and flow to the path I1, and only diodes D2 and D3 are reverse biased for the next half cycle. It flows in the path of I2.

인 경우, 컨버터(130) 및 부하(140)에 공급되기 위해 정류부(120)에서 정류된 직류 전압(

)은 2

가 된다.Therefore, as shown in Fig. 4, the maximum voltage is

In the case of , the DC voltage rectified by the rectifier 120 to be supplied to the converter 130 and the load 140 (

) is 2

becomes

However, according to the conventional wireless power receiver 10 , when excessive energy is received from the power receiver 110 , parts are damaged or there is a risk of fire due to overheating, and the input voltage of the converter 130 is high. There is a problem that the efficiency is lowered.

Therefore, when excessive energy is received from the wireless power transmitter, the development of a technology for preventing an overvoltage from being input to the converter 130 is required.

Republic of Korea Patent Publication No. 10-2011-0133813 (2011.12.14)

SUMMARY OF THE INVENTION The present invention is to solve the above problems, and an object of the present invention is to provide a wireless power receiver for preventing overvoltage from being input to a converter when excessive energy is received from the wireless power transmitter.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A wireless power receiving apparatus according to an embodiment of the present invention for achieving the above object includes: a power receiving unit for wirelessly receiving power from the outside; a rectifying unit having a bridge rectifying circuit and converting an AC voltage input from the power receiving unit into a DC voltage; a switch unit connected to the bridge rectifying circuit; and a controller that turns on the switch unit when the converted DC voltage exceeds a threshold voltage, and turns off the switch unit when the converted DC voltage is equal to or less than a threshold voltage.

In addition, the power receiver may include a capacitor and an inductor, and wirelessly receive power from the outside through magnetic resonance.

In addition, the bridge rectifier circuit may include first to fourth diodes, wherein the anode of the first diode is connected to the cathode of the third diode, and the anode of the second diode is connected to the cathode of the fourth diode. can

Also, the switch unit may be connected to the third diode to conduct or non-conduct the third diode, or may be connected to the fourth diode to conduct or non-conduct the fourth diode.

In addition, the switch unit may be a body diode controlled by the controller to conduct or not conduct one of the third diode and the fourth diode.

Also, the switch unit may be formed of a MOSFET.

In addition, the control unit may include a threshold voltage generator for generating a threshold voltage and a comparator for comparing the AC voltage input from the power receiver and the threshold voltage.

Other specific details of the invention are included in the detailed description and drawings.

According to the wireless power receiver of the present invention as described above, there are one or more of the following effects.

According to the present invention, when excessive energy is received from the wireless power transmitter, it is possible to prevent overvoltage from being input to the converter, thereby reducing the risk of fire due to damage to parts or overheating.

In addition, it is possible to prevent an overvoltage from being input to the converter, thereby improving the efficiency of the converter.

1 is a circuit diagram illustrating a conventional wireless power receiving apparatus.
2 is a graph illustrating an AC voltage received in a conventional wireless power receiver.
3 is an operation diagram of a conventional wireless power receiver.
4 is a graph illustrating a voltage rectified by a conventional wireless power receiver.
5 is a convex view of an apparatus for receiving power wirelessly according to an embodiment of the present invention.
6 is a circuit diagram illustrating an apparatus for receiving wireless power according to an embodiment of the present invention.
7 and 8 are operational diagrams of an apparatus for receiving wireless power according to an embodiment of the present invention.
9 is a graph illustrating a voltage rectified by a wireless power receiver according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments published below, but may be implemented in various different forms, only these embodiments make the publication of the present invention complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

In addition, the terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. As used herein, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” means not excluding the presence or addition of one or more other components, steps and/or actions in addition to the stated components, steps and/or actions. use. And, “and/or” includes each and every combination of one or more of the recited items.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

5 is a convex diagram of an apparatus for receiving power wirelessly according to an embodiment of the present invention, and FIG. 6 is a circuit diagram illustrating an apparatus for receiving power wirelessly according to an embodiment of the present invention.

5 and 6 , the wireless power receiver 20 according to an embodiment of the present invention includes a power receiver 210 , a rectifier 220 , a switch 230 , a controller 240 , and a converter ( 250) and the load 260, but does not exclude additional configurations.

The technology disclosed herein is applied to wireless power transfer. However, the technology disclosed in the present specification is not limited thereto, and may be applied to all power transmission systems and methods, wireless charging circuits and methods, and other methods and apparatuses using wirelessly transmitted power to which the technical idea of the technology can be applied. .

The wireless power receiving device 20 is a device capable of operating by wirelessly receiving power required from the wireless power transmitting device. Also, the wireless power receiver 20 may charge the battery using the received wireless power.

At this time, the wireless power receiving device 20 for wirelessly receiving power described in this specification includes all portable electronic devices, such as input/output devices such as keyboards, mice, and auxiliary output devices for images or voices, mobile phones, It should be interpreted as encompassing a cellular phone, a smart phone, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a tablet, or a multimedia device.

The power receiver 210 wirelessly receives power from the outside.

The power receiver 210 is generated by an inductive coupling method based on an electromagnetic induction phenomenon generated by a wireless power signal and a wireless power signal of a specific frequency to wirelessly receive power without mutual contact with the wireless power transmitter. Power may be received by using one or more of a resonance coupling (Electromagnetic Resonance Coupling) method based on an electromagnetic resonance phenomenon.

Here, the inductive coupling method is a method of inducing a current through a magnetic field from one coil to another using a phenomenon that a voltage is induced and a current flows when a magnetic field is changed around the conductor, and the resonant coupling method is a method of In the case of resonating with the same frequency, energy is transferred when the resonant frequency between the two media is the same based on the attenuation wave coupling in which the electromagnetic wave moves from one medium to another through the near-field electromagnetic field.

) 및 인턱터(

)를 포함하고, 자기 공진을 통해 외부로부터 무선으로 전력을 수신할 수 있는 공진 결합 방식을 예로 들어 설명하나, 이에 제한되지 않고 유도 결합 방식을 이용하여 외부로부터 전력을 수신할 수도 있다.In an embodiment of the present invention, the power receiver 210 is a capacitor (

) and inductors (

), and a resonant coupling method capable of wirelessly receiving power from the outside through magnetic resonance will be described as an example, but the present invention is not limited thereto, and power may be received from the outside using an inductive coupling method.

) 및 인턱터(

)는 전력 수신부(210)가 6.78MHz주파수에서 최저 임피던스를 가지도록 임피던스 매칭 설계될 수 있으나, 공진 결합 방식을 통해 전력을 수신할 수 있다면 이에 제한되지 않는다.At this time, the capacitor (

) and inductors (

) may be designed for impedance matching so that the power receiver 210 has the lowest impedance at a frequency of 6.78 MHz, but is not limited thereto as long as it can receive power through a resonant coupling method.

The rectifier 220 rectifies the AC voltage input from the power receiver 210 and converts it into a DC voltage.

In addition, the rectifier 220 may perform a rectifying operation for converting an AC voltage into a DC voltage and a regulating operation for generating an output condition suitable for use in the final load 260 .

Here, the regulating operation refers to outputting a voltage to a load by forming a constant DC voltage despite the irregular DC voltage obtained from the rectifying operation.

For the rectification operation, the rectifier circuit unit may be a bridge rectifier circuit formed of the first to fourth diodes D1 , D2 , D3 , and D4 .

In this case, the anode of the first diode D1 may be connected to the cathode of the third diode D3 , and the anode of the second diode D2 may be connected to the cathode of the fourth diode D4 .

)를 포함할 수 있다.In addition, the rectifying unit 220 includes at least one rectifying capacitor (

) may be included.

The switch unit 230 may be connected to the third diode D3 or the fourth diode D4 to conduct or non-conduct the third diode D3 or the fourth diode D4 .

In this case, the switch unit 230 may be a switch body diode controlled by the controller 240 . As the switch, a MOSFET, an IGBT, or the like may be used. Hereinafter, a MOSFET will be described as an example as the switch.

However, the connection between the bridge rectifier circuit and the switch unit 230 described in the embodiment of the present invention is not limited thereto, and various modifications may be made.

The control unit 240 controls each component included in the power receiver 210 and the switch unit 230 .

Specifically, the controller 240 may transmit a power control message to the wireless power transmitter. The power control message may instruct the wireless power transmitter to start or end the transmission of the wireless power signal. In addition, the power control message may instruct the wireless power transmitter to adjust the characteristics of the wireless power signal.

In this case, the control unit 240 may transmit the power control message through the wireless power signal or may transmit the power control message through a method of transmitting the user data, but is not limited thereto.

)을 발생시키는 입계 전압기 및 전력 수신부(210)로부터 입력되는 교류 전압과 임계 전압(

)을 비교하는 비교기를 포함할 수 있다.In addition, the control unit 240 is a threshold voltage (

) and the AC voltage input from the threshold voltage device and the power receiver 210 to generate the threshold voltage (

) may include a comparator to compare.

)을 초과하는 경우 스위치부(230)를 온(ON)시키고, 상기 변환된 직류 전압이 임계 전압(

)보다 같거나 작을 경우 스위치부(230)를 오프(OFF)시킬 수 있다.At this time, the control unit 240 compares the converted DC voltage with a threshold voltage, and the converted DC voltage is the threshold voltage (

) is exceeded, the switch unit 230 is turned on, and the converted DC voltage is the threshold voltage (

), it is possible to turn off the switch unit 230 when it is less than or equal to.

)을 출력한다.The converter 250 adjusts the signal level of the DC voltage generated from the rectifier 220 by adjusting the rated voltage (

) is output.

For example, the converter 250 may be a buck converter for step-down voltage, a boost converter for step-up voltage, or a buck-boost converter for step-up or step-down voltage. It is not limited thereto.

)의 변화를 일정 범위 이내로 제한하기 위한 것으로써 저항(

)을 포함할 수도 있고, PCM과 배터리 셀을 구비하는 배터리일 수도 있으나, 이에 제한되지 않는다.The load 260 is the rated voltage (

) to limit the change in resistance (

) may include, but may be a battery having a PCM and a battery cell, but is not limited thereto.

Hereinafter, an operation of the wireless power receiving apparatus 20 according to an embodiment of the present invention will be described with reference to FIGS. 7 to 9 .

7 and 8 are operational diagrams of a wireless power receiver according to an embodiment of the present invention, and FIG. 9 is a graph illustrating a voltage rectified by the wireless power receiver according to an embodiment of the present invention.

Referring to FIG. 7 , when power is received from the power receiver 210 , the rectifier 220 performs a rectification operation of the received power.

At this time, in the AC power received by the power receiver 110, only diodes D1 and D4 are forward biased for the first half cycle and flow in the path of I1, and during the next half cycle, only diodes D2 and D3 are reverse biased and flow in the path of I2. .

인 경우, 컨버터(130) 및 부하(140)에 공급되기 위해 정류부(120)에서 정류된 직류 전압(

)은 2

가 된다.Therefore, the maximum voltage is

In the case of , the DC voltage rectified by the rectifier 120 to be supplied to the converter 130 and the load 140 (

) is 2

becomes

)보다 큰 경우, 제어부(240)에 의해 스위치(230)부가 도통된다.8 and 9 , the DC voltage rectified by the rectifier 220 is the threshold voltage (

), the switch 230 is conducted by the control unit 240 .

)에 충전된 전하가 다음 반주기 시작하는 시점까지 방전된다.At this time, in the AC power received from the power receiver 110, only diodes D1 and D4 are forward biased for the first half cycle and flow to the path of I1, and during the next half cycle, D4 becomes non-conducting and no current flows, so the rectifying capacitor during the first half cycle (

) is discharged until the start of the next half cycle.

인 경우, 컨버터(130) 및 부하(140)에 공급되기 위해 정류부(120)에서 정류된 직류 전압(

)은

가 되어 절반의 직류 전압이 인가된다. Therefore, the maximum voltage is

In the case of , the DC voltage rectified by the rectifier 120 to be supplied to the converter 130 and the load 140 (

)silver

and half the DC voltage is applied.

Therefore, according to the wireless power receiver 20 according to another embodiment of the present invention, when excessive energy is received from the wireless power transmitter, overvoltage is prevented from being input to the converter, thereby causing damage to parts or risk of fire due to overheating. can reduce

In addition, it is possible to prevent an overvoltage from being input to the converter, thereby improving the efficiency of the converter.

In addition, it is possible to prevent an overvoltage from being input with a small number of components such as the switch unit 230 and a comparator, thereby reducing costs.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can realize that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

10: conventional wireless power receiver
20: wireless power receiver
210: power receiver
220: rectifying unit
230: switch unit
240: control unit

Claims (7)

a power receiver for wirelessly receiving power from the outside;
a rectifying unit having a bridge rectifying circuit and converting an AC voltage input from the power receiving unit into a DC voltage;
a switch unit connected to the bridge rectifying circuit; and
a control unit that turns on the switch unit when the converted DC voltage exceeds a threshold voltage, and turns off the switch unit when the converted DC voltage is equal to or smaller than a threshold voltage,
When the switch unit is turned on, the DC voltage rectified by the rectifier when the _{maximum voltage is V p is V p} /π of the wireless power receiver. The method of claim 1,
The power receiver,
A wireless power receiver comprising a capacitor and an inductor, and wirelessly receiving power from the outside through magnetic resonance. The method of claim 1,
The bridge rectifier circuit is
Including first to fourth diodes,
The anode of the first diode is connected to the cathode of the third diode,
The anode of the second diode is connected to the cathode of the fourth diode, the wireless power receiver. 4. The method of claim 3,
The switch unit,
connected to the third diode to conduct or non-conduct the third diode;
A wireless power receiver connected to the fourth diode to conduct or non-conduct the fourth diode. 5. The method of claim 4,
The switch unit,
A body diode controlled by the controller to conduct or non-conduct one of the third diode and the fourth diode, the wireless power receiving device. 5. The method of claim 4,
The switch unit,
A wireless power receiving device formed of a MOSFET. The method of claim 1,
The control unit is
a threshold voltage generator generating a threshold voltage; and
and a comparator for comparing the AC voltage input from the power receiver with a threshold voltage.

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