KR101796788B1 - Apparatus and method for trasmitting energy - Google Patents

Abstract

A wireless power transmission apparatus according to an embodiment of the present invention includes: a power supply for generating an AC power based on a first frequency; A transmit coil for generating wireless power based on the AC power source and transmitting the wireless power to a wireless power receiver; And a measurement unit for measuring a voltage-current phase difference input to the transmission coil, wherein the radio power transmission apparatus is configured to control the phase difference to be 0 or a predetermined threshold value when the phase difference exceeds 0 or a predetermined threshold value And the first frequency may be a resonant frequency when no interference object exists between the wireless power transmission apparatus and the wireless power reception apparatus.

Description

[0001] APPARATUS AND METHOD FOR TRASMITTING ENERGY [0002]

The present invention relates to an energy transfer apparatus and method, and more particularly, to an energy transfer apparatus and method capable of increasing energy transfer efficiency by re-adjusting a resonance frequency using a phase difference measured at a transmission terminal even when a resonance frequency is changed.

Almost all household appliances, portable and office appliances and industrial appliances used in everyday life use electric energy supplied by electric power from the power plant. Until now, it has not been a great inconvenience to supply power by wire, but the development and widespread use of various portable devices recently shows that the wired power supply is not a suitable power source for portable devices. For example, as described above, in the case of receiving a power using a battery, in the case of a battery having a constant charging capacity, improvement of the function of the portable device increases the recharging cycle, The weight is increased and the portability is lowered. Moreover, a cell phone that has become a necessity for everyday life now has problems that it is difficult to charge it anywhere easily when the battery is exhausted. In addition, as the use of laptop computers increases, the problem of power supply is becoming more and more evident.

In the 1800s, electric motors and transformers using electromagnetic induction principles began to be used, and then there was radio (or radio) transmission of electric energy from the source to the desired device A method of transmitting electrical energy by radiating an electromagnetic wave such as a fana laser has also been attempted. Our electric toothbrushes and some wireless shavers are actually charged with electromagnetic induction. There are following kinds of energy transmission method by wireless system.

First, there is an electromagnetic induction method by a magnetic induction method. The magnetic induction that induces a current from one coil to another through a magnetic field has a limiting condition that the relative position and distance of both coils, and the load power must be correct. Recently, however, some companies have begun to introduce new wireless charging products that can charge mobile phones, PDAs, MP3 players and notebook computers using electromagnetic induction.

Second, there is non radioactive wireless transmission technology using near-field effect. The technique is based on evanescent wave coupling, in which electromagnetic waves travel from one medium to another through a near electromagnetic field when the two media resonate at the same frequency. When a charging station connected to a power source forms such an electromagnetic field and approaches a portable device having a receiver designed with the same resonance frequency of MHz band in this electromagnetic field, a kind of energy tunnel is formed between the two media, Can be charged. In particular, this energy is "non-radiative" and is based on a magnetic field, so that only when there is a device with a resonant frequency, it is delivered directly to the device, and the unused portion spreads into the air Unlike other electromagnetic waves, it has the advantage of not affecting other machines or bodies around.

Third, there is a remote transmission technology using a short wavelength radio frequency within the electromagnetic wave range. This method is an electromagnetic radiation method using microwaves of the 2.45 or 5.8 GHz band and has a fatal disadvantage to the human body.

The wireless power technique proposed by the present invention is a second type, and a wireless power transmission device using a magnetic resonance device can generally have the configuration of FIG. The electric power generated by the AC signal generator 10 is transmitted to the transmitting resonance coil 22 by a magnetic field generated by the transmitting coil 21 and transmitted to the transmitting resonance coil 22 by the resonance coil 22 Amplify. The amplified magnetic field can carry much more energy than a conventional magnetic field induced power transmission. Similarly, the receiving resonant coil 31 resonates and amplifies the transmitted magnetic field, thereby efficiently receiving energy. As a result, energy can be efficiently transferred from a long distance.

On the other hand, in the magnetic resonance system, the resonance frequencies of the resonance coils 12 and 20 for transmission and reception can be changed when the object 50 exists in the environment or in the energy transmission path. In this case, the energy amplification rate is reduced and the energy transfer efficiency at a predetermined distance is affected.

In order to solve the above-described problems, the present invention proposes a method of adjusting a frequency of an AC signal generator so that energy transmission efficiency can be maintained by sensing a change in resonance frequency.

The present invention proposes a method of detecting a change in resonant frequency of a resonant coil.

A wireless power transmission apparatus according to an embodiment of the present invention includes: a power supply for generating an AC power based on a first frequency; A transmit coil for generating wireless power based on the AC power source and transmitting the wireless power to a wireless power receiver; And a measurement unit for measuring a voltage-current phase difference input to the transmission coil, wherein the radio power transmission apparatus is configured to control the phase difference to be 0 or a predetermined threshold value when the phase difference exceeds 0 or a predetermined threshold value And the first frequency may be a resonant frequency when no interference object exists between the wireless power transmission apparatus and the wireless power reception apparatus.
A wireless power transmission method according to an embodiment of the present invention includes: generating an AC power source via a power supply based on a first frequency; Generating wireless power through the transmission coil based on the AC power and transmitting the wireless power to the wireless power reception device; Measuring a voltage-current phase difference input to the transmission coil; And adjusting the first frequency to a second frequency such that the phase difference corresponds to zero or a predetermined threshold when the phase difference is zero or exceeds a predetermined threshold, And may be a resonance frequency when no interference object exists between the power transmission apparatus and the wireless power receiving apparatus.

delete

According to the present invention, it is possible to compensate for the influence of the resonance frequency according to the change of the external environment, so that the energy can be transmitted stably.

Figure 1 shows a schematic diagram of a configuration for this conventional wireless energy transfer scheme.
2 is a block diagram illustrating a configuration of a wireless energy transfer apparatus according to an embodiment of the present invention.
3 shows a block diagram of a configuration of a wireless energy transfer apparatus according to an embodiment of the present invention.
4 is a block diagram of a simplified configuration of a wireless energy transfer apparatus according to an embodiment of the present invention.
5 is a flowchart of a wireless energy transfer method according to an embodiment of the present invention.

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

The suffix "module" and " part "for components used in the following description are given merely for ease of description, and the" module "and" part "

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

As used herein, terms used in the present invention are selected from general terms that are widely used in the present invention while taking into account the functions of the present invention, but these may vary depending on the intention or custom of a person skilled in the art or the emergence of new technologies. Also, in certain cases, there may be a term chosen arbitrarily by the applicant, in which case the meaning thereof will be described in the description of the corresponding invention. Therefore, it is intended that the terminology used herein should be interpreted based on the meaning of the term rather than on the name of the term, and on the entire contents of the specification.

1 shows a block diagram of a configuration of a wireless energy transfer apparatus according to an embodiment of the present invention.

에 따른 교류 전원을 발생할 수 있다. 소정 주파수

는 디폴트 주파수

를 가질 수 있다. 디폴트 주파수

는 어떠한 간섭 대상(50)도 없는 상태에서의 공진 주파수일 수 있다. 또는, 디폴트 주파수

는 타겟 대상의 에너지 소비 장치(40)를 도 1에서와 같이 장착하였을 때의 이상적(ideal) 공진 주파수일 수 있다. 소정 주파수

는 주기적으로, 또는 외부 요인에 의해 변경될 수 있고 또는 임의적으로 조절될 수 있다.Referring to FIG. 1, a wireless energy transfer apparatus 100 according to an embodiment of the present invention may include a power supply unit 10. The power supply unit 10 supplies a predetermined frequency

Can be generated. The predetermined frequency

Lt; RTI ID = 0.0 >

Lt; / RTI > Default frequency

May be a resonant frequency in a state where no interference object 50 is present. Alternatively, the default frequency

May be an ideal resonant frequency when the energy consuming device 40 of the target object is mounted as shown in Fig. The predetermined frequency

May be changed periodically, or by external factors, or may be arbitrarily adjusted.

The wireless energy transfer apparatus 100 according to an embodiment of the present invention may include a transmitter 20. The transmission unit 20 may include a transmission coil 21 and a transmission resonance coil 22. [ When a magnetic field is generated in the transmission coil 21, energy is transmitted to the transmission resonance coil 22. The magnetic field can be amplified in such a manner as to cause resonance in the transmission resonance coil 22. [ The amplified magnetic field can be transmitted to the receiver 30 through the space.

The wireless energy transfer apparatus 100 according to an embodiment of the present invention may include a receiving unit 30. The receiving unit 30 receives the amplified magnetic field from the receiving resonant coil 31 and amplifies the magnetic field in the same manner as in the transmitting unit 20 and transmits the amplified magnetic field to the energy consuming device 40 via the receiving coil 32 .

에 따른 전원이 발생되면, 디폴트 주파수

의 전원에 따라 공진이 발생되고, 이후 증폭되어 에너지 소비 장치(40)에 전달될 수 있다. 그러나, 주위 환경 변화나 송신부(20) 또는 수신부(30)에서의 에너지 전달 경로 상에 변화가 생기면 공진 주파수는 디폴트 주파수

와 달라질 수 있다. 이때, 공진 주파수의 변화를 감지하여 전원부(10)의 주파수를 조절할 수 있다.On the other hand, in the state where the magnetic field is not influenced by the interference object 50,

Is generated, the default frequency

Resonance may be generated according to the power supply of the power supply device 40, and then amplified and transmitted to the energy consuming device 40. However, when a change occurs in the ambient environment or on the energy transfer path in the transmitter 20 or the receiver 30, the resonance frequency becomes the default frequency

≪ / RTI > At this time, the frequency of the power supply unit 10 can be adjusted by detecting the change of the resonance frequency.

The wireless energy transfer apparatus 100 according to the present invention may further include a measurement unit (not shown) for sensing a change in resonance frequency.

2 is a circuit diagram of a wireless energy transfer apparatus according to an embodiment of the present invention. Referring to FIG. 3, the transmission coil 21 may include a coil having a self inductance L1. The transmission coil 21 receives the power generated by the power supply unit 10, generates a magnetic field, and transmits the generated magnetic field to the transmission resonance coil 22 having a mutual inductance M1. The magnetic field amplified by the transmitting resonant coil 22 can be transmitted in space. The magnetic field may then be transmitted to the receiver 30 having a mutual inductance M2 and then to the energy consuming device 40 having the resistance R. [

In addition, the energy transfer device 100 according to the present invention can measure the voltage-current phase difference of the transmitter. In order to measure the phase difference between the voltage and the current input to the transmission coil 21, a measurement unit may be mounted between the a-a 'terminals of the transmission coil 21 to measure the phase difference.

The measuring unit can measure the input voltage and the external voltage to measure the phase difference.

3 is a block diagram of a configuration of a wireless energy transfer apparatus according to another embodiment of the present invention. In FIGS. 1 and 2, an energy transfer device composed of one transmitter and one receiver is illustrated. Referring to FIG. 3, two or more receiving units may sequentially transmit energy. Specifically, the magnetic field energy generated and amplified in the transmitting unit 25 can be transmitted to the energy consuming apparatus 40 via the receiving unit 1 35 and the receiving unit 45. In this case as well, the measuring unit can obtain the voltage-current phase difference from the input terminal of the transmitter 25. That is, the changed resonance frequency can be simply measured by measuring the phase difference at the input of the transmitter regardless of the number, type, and configuration or number of the energy consumption devices.

4 is a circuit diagram of a simplified configuration of a wireless energy transfer apparatus according to an embodiment of the present invention. Fig. 4 is a circuit equivalent to the circuit illustrated in Fig. That is, on the whole system, the power source, the transmitter, the receiver and the energy consuming apparatus of Figs. 1 and 2 can be equated as the parallel circuit of Fig. In the equivalent circuit illustrated in Fig. 4, the aa` stage is the same as the input stage of the transmitting coil 20, the total input resistance of the system measured at the input of the transmitting coil is Ra, the total input inductance is La, The total input capacitance has Ca.

When resonance occurs on the entire system illustrated in FIG. 4, since the total impedance value of the system remains only the real component, the voltage difference between the voltage and the current measured in a-a is 0. However, as described with reference to FIG. 1, the overall inductance of the system may be changed due to the influence of the external environment, etc. In this case, the total impedance value in the circuit of FIG. 4 can be changed. The phase difference between the measured voltage and current results in real as well as imaginary components. That is, the total impedance includes both the resistor and the reactance.

The overall admittance Y (1 / Z)

, And the return type

. The phase of the admittance Y is obtained as a phase difference? _A as an inversion value of the phase difference between the voltage and the current viewed from the transmitting end,

를 구해보면, frequency

However,

That is, if the frequency of the power supply section 10 is adjusted again as the frequency obtained from the equation (5), the entire system can resonate again.

In Fig. 4, the equivalent circuit of the entire system is illustrated as a parallel circuit, but the present invention is not limited to this, and it can be equivalent to a serial circuit. The power supply unit 10 can adjust the frequency by a predetermined period or when the resonance frequency changes due to an external environment change or by a user input.

5 is a flowchart of a wireless energy transfer method according to an embodiment of the present invention.

In step S11, an AC power source is generated at a predetermined frequency? ₀ at the power source unit.

In step S12, the energy transfer device according to an embodiment of the present invention generates a magnetic field using the generated AC power and transfers the generated magnetic field to the energy consuming device. And the transmission unit and the reception unit can be passed through to the energy consumption device.

In step S13, the transmitter measures the voltage-current phase difference. The phase difference can be measured at the input of the transmitter.

In step S14, it is determined whether the resonance frequency is changed based on the measured phase difference. It is determined whether the measured phase has a phase larger than zero, that is, if the overall impedance of the system is changed so that the impedance includes the reactance value.

As another example, it may be determined whether the measured phase is greater than a predetermined phase difference threshold value to determine whether the resonance frequency has changed. If the predetermined phase difference threshold value falls within a range of, for example, -0.1 radian to +0.1 radian, it can be determined that the resonance frequency is not changed. When the resonance frequency is not changed, the power supply unit keeps the frequency at the predetermined frequency? ₀ without re-adjusting or changing the frequency.

를 소정 주파수 ω₀ 로부터 재조절할 수 있다. If it is determined in step S15 that the resonance frequency has been changed, based on the measured phase difference,

Can be readjusted from the predetermined frequency? ₀ .

It is to be understood that the present invention is not limited to the configuration and the method of the embodiments described above as long as all or a part of the embodiments are selected so that various modifications can be made. As shown in FIG.

Meanwhile, the energy transfer apparatus and method of the present invention can be implemented as a processor readable code on a processor-readable recording medium provided in a TV, a computer, a mobile phone, a smart phone, a tablet computer, or the like. The processor-readable recording medium includes all kinds of recording apparatuses in which data that can be read by the processor is stored. Examples of the recording medium that can be read by the processor include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may also be implemented in the form of a carrier wave such as transmission over the Internet . In addition, the processor-readable recording medium may be distributed over network-connected computer systems so that code readable by the processor in a distributed fashion can be stored and executed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

10:
20:
30: Receiver
40: Energy consumption device
50: Interference target
100: Energy transfer device

Claims (12)

In a wireless power transmission apparatus,
A power source for generating an AC power based on the first frequency;
A transmit coil for generating wireless power based on the AC power source and transmitting the wireless power to a wireless power receiver;
And a measurement unit for measuring a phase difference between voltage and current input to the transmission coil,
The wireless power transmission apparatus adjusts the first frequency to a second frequency such that the phase difference corresponds to 0 or a predetermined threshold value when the phase difference is 0 or exceeds a predetermined threshold value,
Wherein the first frequency is a resonance frequency when no interference object exists between the wireless power transmission device and the wireless power reception device. The method according to claim 1,
And a transmission resonance coil for receiving the radio power from the transmission coil and transmitting the radio power to the radio power reception device. 3. The method of claim 2,
And the transmission resonance coil is plural. The method according to claim 1,
One end of the power source is connected to one end of the transmission coil,
The other end of the power source is connected to the other end of the transmission coil,
One end of the measurement unit is connected to one end of the power source and one end of the transmission coil,
And the other end of the measurement unit is connected to the other end of the power source and the other end of the transmission coil. The method according to claim 1,
An input resistance R, an input reactance L, and an input conductance C input to the transmission coil,
The first and second frequencies

Based on the received signal. The method according to claim 1,
Wherein the wireless power is transmitted in a non-radiative manner. In a wireless power transmission method,
Generating an AC power source via a power supply based on the first frequency;
Generating wireless power through the transmission coil based on the AC power and transmitting the wireless power to the wireless power reception device;
Measuring a voltage-current phase difference input to the transmission coil; And
And adjusting the first frequency to a second frequency such that the phase difference corresponds to zero or a predetermined threshold value when the phase difference exceeds 0 or a predetermined threshold value,
Wherein the first frequency is a resonance frequency when no interference object exists between the wireless power transmission device and the wireless power reception device. 8. The method of claim 7,
Receiving the radio power from the transmitting coil via a transmitting resonant coil and transmitting the received radio power to the radio power receiving device. 9. The method of claim 8,
Wherein the transmitting resonant coil is a plurality of transmitting coils. delete 8. The method of claim 7,
An input resistance R, an input reactance L, and an input conductance C input to the transmission coil,
The first and second frequencies

≪ / RTI > further comprising calculating based on the received signal power. 8. The method of claim 7,
Wherein the wireless power is transmitted in a non-radiative manner.

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