KR20150115339A - Wireless Power Transfer System - Google Patents

Abstract

According to the present invention, provided is a wireless power transmitting system, capable of maintaining the sensitivity of reception by controlling power from a transmitting device by detecting the sensitivity of reception from a receiving part; improving the sensitivity of reception by controlling an output voltage of a transformer according to the sensitivity of reception, detected from the receiving device; and improving the sensitivity of reception by controlling a harmonic wave, included in output, by detecting the sensitivity of reception from the receiving device and controlling a duty ratio of a power converting part according to the detection. The prevent invention includes a transmitting device transmitting power wirelessly and a receiving device receiving the power, and controls the wireless transmission of the power according to the sensitivity of data reception, detected from the receiving device.

Description

[0001] WIRELESS POWER TRANSFER SYSTEM [0002]

The present invention relates to a wireless power transmission system.

A wireless power transfer (WPT) system is a technology that delivers power without wires through space, maximizing the convenience of power supply to mobile devices and digital home appliances.

The wireless power transmission system has advantages such as saving energy through real-time power usage control, overcoming space limit of power supply, and reducing waste battery discharge by battery recharging.

As a method of implementing a wireless power transmission system, there are typically a magnetic induction type and a self resonance type.

The magnetic induction method is a noncontact energy transmission technique in which two coils are brought close to each other, a current is supplied to one coil, and an electromotive force is generated in the other coil via the magnetic flux generated thereby.

The self-resonance method is a magnetic resonance technology that uses only electric field or magnetic field without using electromagnetic wave or current. It is characterized by using a band of several tens of MHz because the distance of power transmission is several meters or more.

However, in the wireless power transmission system, spurious waves coming from the power transmitter, that is, harmonics are generated, and these harmonic components may cause electromagnetic interference effects and harmful effects on the human body.

Harmonics are frequencies that are higher than the commercial frequency in the power relationship, for example, hundreds of Hz or more, and harmonics are the integral multiple of the fundamental wave.

In a wireless power transmission system, the cause of harmonic components generated near the frequency of the reception frequency is basically due to the nonlinear characteristics of the transmission device load. That is, the AC signal supplied to the transmitting apparatus is distorted without being held by the non-linear load, and harmonics are formed.

These harmonic components interfere with the normal operation of the peripheral devices, cause unwanted power reception, noise, and various disturbances.

Specifically, a change in a magnetic field emitted from a power transmitter may cause an abnormal operation by generating a current due to electromagnetic induction in a conductor of a stationary peripheral device.

Also, the magnetic field generated by the power transmitter may generate a current in the portable device even when the portable device or the like moves around the magnetic field, thereby causing a failure phenomenon.

Also, if resonance conditions are similar between the power transmitter and peripheral devices that do not want to receive power, magnetic resonance coupling may occur, which may cause malfunctions in the peripheral devices.

In addition, the harmonic component serves as a cause of lowering the reception sensitivity of the communication system included in the receiving apparatus. In other words. When the receiving device communicates with an external communication network such as the Internet use or the telephone communication simultaneously with the wireless charging, the harmonic components emitted from the transmitting device have a problem of obstructing the communication between the receiving device and the external communication network.

The problem of such electromagnetic waves is that a square wave signal applied to an inverter for converting DC into AC is not a complete square wave component due to rising, falling time and spikes, These harmonic components cause a decrease in the reception sensitivity of the communication system of the receiving apparatus.

Various methods for improving the radiation energy problem due to the harmonics have been studied.

The radiated energy has a proportional relationship with the size of the fundamental wave. Further, the magnitude of the fundamental wave varies depending on the position of the receiving device, and the energy radiated thereby also varies according to the receiving device, There has also been a problem in that it is required to design differently according to the position of the receiving apparatus.

As we have seen, harmonic components can have a negative effect on electronic equipment and human body, so it is necessary to satisfy regulations on electromagnetic compatibility (EMC), electromagnetic interference (EMI) and electromagnetic susceptibility (EMS) It is important.

An embodiment according to the present invention provides a wireless power transmission system capable of maintaining reception sensitivity by detecting reception sensitivity from a reception apparatus and controlling power output from the transmission apparatus.

The embodiment of the present invention provides a wireless power transmission system capable of detecting reception sensitivity from a receiving apparatus and adjusting the output voltage of the transforming unit accordingly to improve reception sensitivity.

The embodiment of the present invention also provides a wireless power transmission system capable of detecting reception sensitivity from a receiving apparatus, controlling the duty ratio of the power conversion unit accordingly, and adjusting the harmonic components included in the output to improve reception sensitivity.

A wireless power transmission system according to an embodiment of the present invention includes a transmission device for transmitting wireless power; And a receiving device for receiving the wireless power, wherein the wireless power transmission amount is controlled according to a data receiving sensitivity detected from the receiving device.

In the wireless power transmission system according to the embodiment of the present invention, the transmission apparatus includes a power supply unit; A transformer for converting the power applied from the power supply unit into a DC power; And a controller for controlling the size of the DC power supply according to the data reception sensitivity.

In the wireless power transmission system according to the embodiment of the present invention, the transmission apparatus includes a power supply unit; A transformer for converting the power applied from the power supply unit into a DC power; A power converting unit for generating an AC power based on the DC power supplied from the transforming unit; And a controller for controlling at least one of a magnitude or a frequency of the AC power according to the data reception sensitivity.

In the wireless power transmission system according to the embodiment of the present invention, the transmitting apparatus further includes an RSSI (Receive Sensitivity Information) detecting unit for detecting the data receiving sensitivity.

In the wireless power transmission system according to the embodiment of the present invention, the RSSI detection unit transmits a reception sensitivity detection signal to the reception apparatus,

Wherein the receiving apparatus detects the data reception sensitivity of the receiving apparatus according to the receiving sensitivity detection signal and provides the detected receiving sensitivity to the RSSI detecting unit.

In the wireless power transmission system according to the embodiment of the present invention, the data reception sensitivity is compared with a preset value, and the magnitude of the DC power is adjusted accordingly.

In a wireless power transmission system according to an embodiment of the present invention, the reception sensitivity detection signal periodically occurs.

In the wireless power transmission system according to an embodiment of the present invention, the transmission apparatus further includes a storage device that stores a table of wireless power transmission amounts corresponding to the detected data reception sensitivity.

In the wireless power transmission apparatus according to the embodiment of the present invention, the wireless power transmission apparatus transmits wireless power to a reception apparatus, wherein the wireless power transmission apparatus controls a wireless power transmission amount according to a data reception sensitivity of the reception apparatus A wireless power transmission device.

In the wireless power transmission apparatus according to the embodiment of the present invention, the wireless power transmission apparatus includes an RSSI detection unit that detects the data reception sensitivity.

In the wireless power transmission apparatus according to an embodiment of the present invention, the wireless power transmission apparatus includes a power supply unit; A transformer for converting the power applied from the power supply unit into a DC power; And a control unit for controlling the size of the DC power supply of the transforming unit, wherein the controller adjusts the size of the DC power supply according to the data receiving sensitivity from the RSSI detecting unit.

In the wireless power transmission apparatus according to an embodiment of the present invention, the data reception sensitivity is compared with a preset value, and the size of the direct current power source is adjusted accordingly.

In the wireless power transmission apparatus according to the embodiment of the present invention, the RSSI detection unit transmits a reception sensitivity detection signal to the reception apparatus, and the reception apparatus detects the data reception sensitivity of the reception apparatus in accordance with the reception sensitivity detection signal To the transmitting apparatus.

In the wireless power transmission apparatus according to the embodiment of the present invention, the reception sensitivity detection signal periodically occurs.

A method of driving a wireless power transmission system according to an embodiment of the present invention includes: transmitting a wireless power; And a receiving device for receiving the wireless power, the method comprising: transmitting the wireless power according to an amount of power required by the receiving device; ; The transmitting apparatus transmitting the receiving sensitivity detection signal to the receiving apparatus; Detecting a data reception sensitivity according to the reception sensitivity detection signal and providing the detection result to the transmission apparatus; And the transmitting device compares the data reception sensitivity with a preset value and controls a wireless power transmission amount according to the comparison result.

The method of driving a wireless power transmission system according to an exemplary embodiment of the present invention reduces a wireless power transmission amount when the data reception sensitivity is lower than the preset value.

The method of driving a wireless power transmission system according to an exemplary embodiment of the present invention is characterized in that the reception sensitivity detection signal is periodically generated.

In the driving method of the wireless power transmission system according to the embodiment of the present invention, the transmitting device may transmit the wireless power according to the power demand of the receiving device, the receiving device requesting the first power; And transmitting the second power by the transmitting apparatus.

In the method of driving a wireless power transmission system according to an embodiment of the present invention, the step of the transmitting device comparing the data reception sensitivity and the preset value and controlling the amount of wireless power transmission according to the comparison result includes: Transmitting the third power when the sensitivity is lower than the predetermined value or transmitting the first power when the data reception sensitivity is higher than the predetermined capacity.

A method of driving a wireless power transmission system according to an embodiment of the present invention, wherein the first power is greater than the second power and the second power is greater than the third power.

An embodiment of the present invention is an invention capable of maintaining the reception sensitivity by detecting the reception sensitivity from the reception apparatus and controlling the power output from the transmission apparatus, thereby detecting reception sensitivity from the reception apparatus and controlling the output voltage of the transmission unit accordingly To provide a wireless power transmission system capable of improving reception sensitivity and capable of improving reception sensitivity by detecting reception sensitivity from a reception apparatus and controlling a duty ratio of a power conversion unit thereby adjusting harmonic components included in an output .

FIG. 1 is a block diagram of a transmitting apparatus of a wireless power transmission system according to an embodiment of the present invention, and FIG. 2 is a block diagram of a receiving apparatus according to an embodiment of the present invention.
3 is a diagram illustrating steps from detection of a reception apparatus to transmission of a power to a reception apparatus in a wireless power transmission system according to an embodiment of the present invention.
4 is a diagram illustrating a step of detecting the reception sensitivity information from the reception apparatus in the wireless power transmission system according to the embodiment of the present invention and controlling the power transmitted from the transmission apparatus to the reception apparatus.
5 is a diagram illustrating a step of detecting the reception sensitivity information from the reception apparatus according to another embodiment of the present invention and controlling the power transmitted from the transmission apparatus to the reception apparatus.
6 is a diagram illustrating a power conversion unit of a transmitter according to an embodiment of the present invention.
7 is a view showing a transformer and a control unit according to an embodiment of the present invention.
8 is a diagram illustrating a subsystem of a control unit according to an embodiment of the present invention.

Hereinafter, a wireless power transmission system having a wireless power transmission system according to an embodiment of the present invention will be described in detail with reference to the drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Embodiments use a variety of frequency bands from low frequency (50 kHz) to high frequency (15 MHz) selectively for wireless power transmission, and it is necessary to support a communication system capable of exchanging data and control signals for system control .

The embodiments can be applied to various industrial fields such as a mobile terminal industry using a battery or an electronic device required, a household appliance industry, an electric car industry, a medical device industry, and a robot industry.

An embodiment may consider a system capable of transmitting power to one or more multiple devices using a single transmit coil provided with the device.

The terms and abbreviations used in the examples are as follows.

Wireless Power Transfer System: A system that provides wireless power transmission within a magnetic field region

Wireless Power Transfer System-Charger: A device that provides wireless power transmission to power receivers of multiple devices within the magnetic field area and manages the entire system.

Wireless Power Transfer System-Deivce: A device that receives wireless power transmission from a power transmitter within a magnetic field region.

Charging Area: A region where actual wireless power transmission occurs within the magnetic field region, and may vary depending on the size, required power, and operating frequency of the application product.

<Wireless power transmission system>

FIG. 1 is a block diagram of a transmitting apparatus of a wireless power transmission system according to an embodiment of the present invention, and FIG. 2 is a block diagram of a receiving apparatus according to an embodiment of the present invention.

1 and 2, a wireless power transmission system 10 according to an embodiment of the present invention includes a transmitting apparatus 100 for transmitting power wirelessly and a receiving apparatus 200 receiving power from the transmitting apparatus 100 ).

The receiving apparatus 200 may be a plurality of apparatuses, or may be a device capable of charging energy wirelessly, such as a terminal, a tablet PC, an electric vehicle, etc., The transmitting apparatus 100 can provide power to the receiving apparatus 200. [

Referring to a block diagram of a subsystem of the transmitter 100, the subsystem of the transmitter 100 may include a transmit power converter system 101 and a transmit antenna system 102.

The transmission power converter system 101 may include a plurality of subsystems including a rectifier and filter unit 110, a transformer unit 120, a power converter unit 130, a controller 140, (150).

The rectification and filter section 110 generates a direct current (DC) voltage to be used in the next stage and the generated DC voltage may be provided to the transformer 120 and then to the power to be supplied to the transmit antenna system 102.

The transformer 120 regulates the level of the DC power output from the rectifying and filtering unit 110 based on the control signal. The DC power supply 120 uses a semiconductor device such as a power transistor as a switch, To a voltage of a square wave form, and then obtains a controlled DC output voltage through a filter.

At this time, the control of the DC output voltage is performed by controlling the ON and OFF periods of the switch.

Since the operation of the transforming unit 120 is based on the conversion from a DC input to a DC output, it is called a Switched-Mode Power Supply (SMPS), a DC-DC transformer or a DC-DC converter It is also called.

The transformer 120 can output a constant DC power by controlling an error by receiving an output voltage.

The transformer 120 includes a buck converter having an output voltage lower than the input voltage, a boost converter having an output voltage higher than the input voltage, a buck-boost converter having both of the above characteristics, The converter can have any one of the three characteristics.

The level of the DC voltage output from the transforming unit 120 may be adjusted, and the level of the DC voltage may be controlled by a control signal of the controller 140.

The controller 140 may be referred to as a microprocessor, a microcontroller unit, or a microcomputer.

The control unit 140 can control the magnitude of the DC voltage output from the transformer 120 in consideration of the maximum power transmission efficiency, the power demand of the receiving apparatus 200, the present charging amount of the receiving apparatus 200, .

The control unit 140 not only controls an output voltage of the transforming unit 120 but also controls an algorithm, a program, or an application required for control read from a storage unit (not shown) of the transmitting apparatus 100 The overall operation of the transmission apparatus 100 can be controlled.

 The transmission power converter system 101 may further include a transmission side communication unit 141 and an RSSI received signal strength indicator detection unit 142. The transmission side communication unit 141 and the RSSI detection unit 142 may be connected to a receiving device Side communication unit 251 of the base station 200. [

The transmission side and reception side communication units 141 and 251 and the RSSI detection unit 142 and the reception side communication unit 251 can perform bidirectional communication in a predetermined manner. Examples thereof include NFC (near field communication), Zigbee Communication, infrared communication, visible light communication, Bluetooth communication, and Bluetooth low energy (BLE).

Also, the power information can be transmitted and received between the transmitting side and the receiving side communication units 141 and 251, where the power information includes the capacity of the receiving apparatus 200, the remaining battery power, the number of times of charging, Or the like.

The transmission side communication unit 141 is provided in one configuration with the RSSI detection unit 142 and is connected to the reception side communication unit 251 through the received signal strength indication (RSSI) And the control unit 140 is constituted by one chip including both the transmission side communication unit 141 and the RSSI detection unit 142 so that the control unit 140 can communicate with the reception side communication unit 251 . &Lt; / RTI &gt;

Side communication unit 141 can transmit a charging function control signal for controlling the charging function of the receiving apparatus 250. [

The charging function control signal may be a control signal that controls the receiving device 200 to enable or disable the charging function. Alternatively, the power information may include information such as input of the wired charging terminal, switching from the SA mode to the NSA mode, and releasing the error situation.

Meanwhile, the transmission power converter system 101 may be configured with hardware different from the transmission side communication unit 141 so that the transmission apparatus 200 may be communicated in an out-band format, and the transmission power converter system 101 And the transmission side communication unit 141 may be implemented in one piece of hardware so that the transmission apparatus 100 may perform communication in an in-band format.

The transmission side communication unit 141 may be configured separately from the control unit 140 and the receiving side apparatus 200 and the receiving side communication unit 251 may be included in the controller 250 of the receiving apparatus, As shown in FIG.

The power conversion unit 130 can generate power by converting a DC voltage of a certain level into an AC voltage by a switching pulse signal in the range of several tens KHz to several tens MHz. That is, the power conversion unit 130 can convert the DC voltage into the AC voltage to generate the "wake-up power" or "charge power" used in the receiving apparatus 200 that becomes the target, have.

Here, the wake-up power means a small power of 0.1 to 1 mWatt, and the charging power is the power required for charging the battery of the receiving device 200 or the power consumed for the operation of the receiving device 200, Quot; means a large power of 1 mWatt to 200 Watt consumed in the load of the power source 200.

The power converter 130 may include a power amplifier for amplifying the DC voltage output from the transformer 120 according to the switching pulse signal.

The power conversion unit 130 may be a full bridge or a half bridge inverter.

The power conversion unit 130 may include a plurality of power conversion units.

One of the plurality of power conversion units 130 may supply AC power to the induction coil to transmit power in a self-induction manner, and the other power conversion unit may include a resonance AC power can be supplied to the coil.

Each of the plurality of power converters may generate an AC signal having different frequencies according to a transmission scheme.

The matching unit 150 may include at least one of at least one passive element and at least one active element disposed at a rear end of the controller 140 and may perform impedance matching between the transmitting apparatus 100 and the receiving apparatus 200 So that the power transmission efficiency can be maximized.

The impedance viewed from the matching unit 150 can be adjusted to control the output power to be high efficiency or high output. The matching unit 150 can adjust the impedance based on the control of the control unit 140 and the transmission-side communication unit 141. [ The matching unit 150 may include at least one of a coil and a capacitor. The control unit 140 and the transmission-side communication unit 141 can control the connection state of at least one of the coils and the capacitors, thereby performing the impedance matching.

The transmission antenna system 102 may include at least one of an inductive coil and a resonant coil.

In the case where the wireless power transmission system 10 transmits power only in a self-induction manner, the transmission antenna system 102 may include only an induction coil. In the case where power is transmitted only by a self-resonance method, In the case of transmitting power by using a combination of the magnetic induction type and the magnetic resonance type, both the induction coil and the resonance coil can be provided.

Further, the induction coil or the resonance coil may be provided in a single number, or a plurality of induction coils or resonance coils may be provided. When a plurality of induction coils or resonance coils are provided, they can be overlapped with each other, and the overlapping area is determined in consideration of the deviation of the magnetic flux density.

The selecting unit 160 may cause the power generated by the transforming unit 120 to be transmitted to any one of the resonant coil and the induction coil based on the selection signal of the controller 140. [

In the case where a plurality of coils are provided, the power provided from the transmission power converter system 101 when any one of the coils is coupled magnetically with the receiving apparatus 200 is transmitted to the coil As shown in FIG.

The selection unit 160 may be controlled by the control unit 140 and may electrically connect a coil magnetically coupled to the reception device 200 to the transmission power converter system 101.

The selection unit 160 may be controlled by the control unit 140 according to a power transmission scheme, such as a resonance or induction scheme.

When it is determined that the selecting unit 160 is to transmit power in a self-resonant manner by the selection signal of the controller 140, the selecting unit 160 selects either one of the transformer 120 and the power converter 130 The selection unit 160 may connect the power conversion unit of the power conversion unit 130 and the power conversion unit of the power conversion unit 130 to each other when the power conversion unit of the power conversion unit 130 is determined to transmit power in a self- .

If it is necessary to change the size of the DC power supplied to the power conversion unit according to the transmission mode, the controller 140 controls the DC power supply 120 to control the DC power level output from the transforming unit 120 .

The receiving device 200 may include a receiving power converter system 201 and a receiving antenna system 202.

The receiving antenna system 202 of the receiving device 200 may be the same as the transmitting antenna system 102 and the dimensions of the receiving antenna may vary depending on the electrical characteristics of the receiving device 200.

The receiving antenna system 202 may also receive power through a magnetic induction or self-resonant scheme. As described above, the receiving antenna system 202 may include at least one of an induction coil and a resonance coil according to a power receiving scheme. The receiving antenna system 202 may include a near field communication antenna.

The receiving power converter system 201 may include a matching unit 210, a rectifying unit 220, a receiving side transformer 230, a load 240, and a receiving side control unit 250.

The receiving side control unit 250 may include a receiving side communication unit 251 and the receiving side communication unit 251 may be configured separately from the control unit 250. [

The matching unit 210 performs impedance matching between the transmitter 100 and the receiver 200.

The rectifying unit 220 rectifies the AC voltage output from the receiving antenna system 202 to generate a DC voltage.

The receiving-side transformer 230 may include a DC / DC converter to adjust the level of the DC voltage output from the rectifying unit 220 according to the capacity of the load 240.

The load 240 may include a battery, a display, a voice output circuit, a main processor, and various sensors.

The receiving side control unit 250 can be activated by the wake-up power from the transmitting apparatus 100 and can communicate with the transmitting apparatus 100 and control the operation of the subsystem of the receiving apparatus 200 .

The receiving device 200 may be a single device or a plurality of devices, and may receive energy from the transmitting device 100 at the same time. That is, in the resonance type wireless power transmission system, a plurality of target receiving apparatuses 200 can receive power from one transmitting apparatus 100. [

At this time, the matching unit 150 of the transmitting apparatus 100 may adaptively perform impedance matching between the plurality of receiving apparatuses 200.

On the other hand, when the receiving apparatuses 200 are composed of a plurality of receiving apparatuses 200, the receiving apparatuses 200 may be the same type or different types of systems.

<Reception apparatus detection and power transmission step>

3 is a diagram illustrating steps from detection of a reception apparatus to transmission of a power to a reception apparatus in a wireless power transmission system according to an embodiment of the present invention.

The control method can be roughly classified into four steps. In each step, the steps of detecting the receiving apparatus 200 (Selection, S100), the response checking step (Ping, S200), the authentication and configuration step (S300) (Power Transfer, S400).

The detecting step S100 of the receiving apparatus 200 is a step of transmitting a signal for detecting the presence of the receiving apparatus 200 and waiting for a response of the receiving apparatus 200. [

In the response confirmation step S200, the reception apparatus 200 transmits signal strength information, and the transmission apparatus 100 can confirm the presence of the reception apparatus 200 through the information.

In the authentication and configuration step S300, the reception apparatus 200 transmits authentication and required power information, and the transmission apparatus 100 constructs a power transmission and prepares to transmit power.

In the power transmission step (S400), the reception apparatus (200) transmits control information, and the transmission apparatus (100) starts transmission of power.

If the signal is interrupted during these four steps or if the signal is bad, timeout occurs and the operation can be returned to the first step. If an abnormality is detected during transmission or when the receiving apparatus 200 is out of the charging area or fully charged The transmission can be terminated and the operation can be returned to the first step.

&Lt; Power control according to reception sensitivity according to the first embodiment >

4 is a diagram illustrating a step of detecting reception sensitivity information from a reception apparatus in a wireless power transmission system according to the first embodiment of the present invention and controlling power transmitted from the transmission apparatus to the reception apparatus.

Referring to FIG. 4, the fourth step (S400) in which the transmitting apparatus 100 and the receiving apparatus 200 are performing power transmission, as shown in FIG. 3, includes the steps of controlling the power transmitted according to the receiving sensitivity of the receiving apparatus 200 (S410) of detecting the reception sensitivity of the reception apparatus 200, and the fourth step S410 of detecting the reception sensitivity of the reception apparatus 200. The transmission apparatus 100 may receive the reception sensitivity information from the reception apparatus 200, (S430) of comparing the reception sensitivity information with the preset value in step S430 (S430), and controlling the transmission power according to the comparison result in step S440 (S440) .

Step 4-1: Reception sensitivity detection step

The transmitting apparatus 100 can transmit the receiving sensitivity detection signal to the receiving apparatus 200. [

The reception sensitivity at this time indicates the performance of the receiver provided in the reception apparatus 200 and is used to determine how much intensity the reception apparatus 200 can receive when receiving data from the external communication network The ability of

There is a Received Signal Strength Indication (RSSI) as an index indicating the reception sensitivity. This is an average signal strength index at the receiver input, which is a measure of the strength of all the received signals coming into the transmission apparatus 200. In the actual space, the desired signal, the interference signal and the noise signal are combined and received, and the antenna gain and transmission loss are included It does not.

The transmission side communication unit 141 in the transmission apparatus 100 can transmit the reception sensitivity detection signal to acquire information on the reception sensitivity to the reception side communication unit 251 side. Alternatively, the RSSI detecting unit 142 may transmit a reception sensitivity detection signal for obtaining information on the reception sensitivity to the reception side communication unit 251 side.

Step 4-2: reception sensitivity information reception step

When receiving the reception sensitivity detection signal, the reception side communication unit 251 may measure the reception sensitivity and provide the measured reception sensitivity information (Receive Sensitivity Information) to the RSSI detection unit 142.

Step 4-3: Step of comparing reception sensitivity information with preset values.

The reception sensitivity information provided by the RSSI detection unit 142 is provided to the control unit 140, and the controller 140 can compare the reception sensitivity information with the preset value.

The default value can be a specific value or a specific range.

The preset values may be tabulated and stored in a storage device separately provided to the transmission apparatus 100. [

Information on the current reception sensitivity and the corresponding transmission power amount is stored in the storage device or information on how much of the current reception sensitivity is to be transmitted and the current reception sensitivity is stored , Information on the current reception sensitivity and the level of the output voltage of the transforming unit 120 corresponding to the current receiving sensitivity or the current receiving sensitivity and corresponding to the current receiving sensitivity and the amount of power required by the receiving apparatus 200 120 may be stored with information on how much the level of the output voltage of the transforming unit 120 is to be determined.

Step 4-4: Transmission power control step.

When the reception sensitivity received from the transmission apparatus 200 has a value smaller than the preset value, falls within the predetermined range, or has a value equal to or larger than the preset range, The harmonic components can be suppressed. Thus, the reception sensitivity resistance according to the harmonic component can be prevented.

For example, when the proper reception sensitivity is 70 to 80, the preset reception sensitivity range is 60 to 70, and the reception sensitivity according to the reception sensitivity detection signal is 60, the influence of the harmonics interfering with the current reception sensitivity is large And the amount of wireless transmission power can be reduced. If the reception sensitivity according to the next reception sensitivity detection signal is equal to 75, the reception sensitivity is considered to be an appropriate level because it exceeds the preset range, and the wireless transmission power can be increased.

As another example, when the optimum reception sensitivity is 70 to 80, the preset reception sensitivity is 60, and the currently detected reception sensitivity is 60 or less, the radio transmission power can be reduced to a specific value or less, The wireless transmission power can be increased to the amount of power required by the reception apparatus 200 when the measured value obtained by the repeated measurement corresponds to the appropriate reception sensitivity.

When the receiving apparatus 200 is receiving wireless power from the transmitting apparatus 100, the RSSI detecting unit 142 periodically transmits the receiving sensitivity detecting signal to the receiving apparatus 200 to periodically receive the receiving sensitivity information have. Thus, it is possible to prioritize the reception sensitivity of the reception apparatus 200 rather than the wireless charging, so that the reception sensitivity can be maintained at an appropriate level during wireless charging.

&Lt; Power control according to reception sensitivity according to the second embodiment >

5 is a diagram illustrating a step of detecting the reception sensitivity information from the reception apparatus according to the second embodiment of the present invention and controlling the power transmitted from the transmission apparatus to the reception apparatus.

5, if the amount of power (S300) requested by the receiving apparatus 200 to the transmitting apparatus 100 as described in FIG. 3 is the requested first power, the transmitting apparatus 100 transmits the amount of power 2 power can be transmitted (S410).

The second power to be transmitted may be smaller than the first power demanded by the receiving apparatus 200. [

In the case of transmitting the amount of power required by the initial receiving apparatus 200 as it is, the receiving sensitivity of the receiving apparatus 200 may be drastically lowered by electromagnetic waves generated in the wireless power transmission. Therefore, it is possible to transmit less power than the required power amount in the initial power transmission.

The RSSI detecting unit 142 may transmit the reception sensitivity detection signal to the reception apparatus 200 and the reception apparatus 200 may provide the reception sensitivity to the RSSI detection unit 142. [

The control unit 140 may control the transmission power by comparing the reception sensitivity information detected by the RSSI detection unit 142 with a preset value. At this time, if the reception sensitivity corresponds to an appropriate level, the transmitting apparatus 100 can increase the second power amount provided to the receiving apparatus 200 by the amount of power initially requested by the receiving apparatus 200. [

However, when the reception sensitivity is low, the transmitting apparatus 100 can provide the receiving apparatus 200 with a smaller amount of power than the presently provided second amount of power.

<Power Control Method>

Hereinafter, a power control method according to reception sensitivity will be described.

The harmonic component can control the interference phenomenon in the communication of the receiving apparatus 200 while reducing the harmonic component by controlling the power according to the receiving sensitivity so as to reduce the wireless power transmission amount, The control unit 140 of the transmission apparatus 100 may control the power supply to the transformer 120 or the transformer 120 or the transformer 120. In the case where it is necessary to increase the amount of power required by the receiving apparatus 200, The power conversion unit 130 can be controlled.

First, the manner in which the control unit 140 controls the power conversion unit 130 will be described.

6 is a diagram illustrating a power conversion unit of a transmitter according to an embodiment of the present invention.

The configuration of the power converter 130 according to the embodiment of the present invention will be described with reference to FIG.

6 is a power conversion unit 130 configured as a full bridge, but it is not limited thereto and may be configured as a half bridge.

The power conversion unit 130 may convert the power provided from the transforming unit 120 into AC power based on the control provided from the control unit 140, amplify the AC power, and may include a full bridge inverter.

The power conversion unit may include first through fourth switching devices S1, S2, S3, and S4.

The first switching element S1 is connected between the first node N1 and the converter 120 and can be controlled by a control signal of the controller 140. The second switching element S2 is connected to the first node N1 N1 and ground and may be controlled by a control signal of the controller 140. [

The third switching element S3 is connected between the second node N2 and the converter 120 and can be controlled by the control signal of the controller 140. The fourth switching element S4 is connected to the second node N2 N2) and ground and may be controlled by a control signal of the controller 140. [

The first to fourth switching elements S1, S2, S3 and S4 may be an N-type MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) Any device capable of performing the switching operation is possible.

When the first and fourth switching devices S1 and S4 are turned on and the second and third switching devices S2 and S3 are turned off by a PWM (Pulse Width Modulation) control signal provided from the control unit 140 The output voltage Vo of positive polarity is applied to the matching unit 150.

When the first and fourth switching elements S1 and S4 are turned off and the second and third switching elements S2 and S3 are turned on by the control signal provided from the controller 140, A negative output voltage Vo can be applied.

Also, the duty ratio (duty ratio) can be changed according to the conduction rates of the first to fourth switching devices S1 to S4, and thus the fundamental wave of the output signal of the power conversion unit 130 and the fundamental wave of the fundamental wave The magnitude of the harmonic component, which is a multiplication component, can be changed.

For example, the magnitude of the fundamental wave and the harmonic component of the output signal of the power conversion unit 130 may vary depending on the duty ratio of 50%, 30%, or 70%. The control unit 140 controls the switching elements S1 to S4 of the power conversion unit 130 according to the degree of reception sensitivity received from the reception apparatus 200. Therefore, The conduction ratio can be controlled to control at least one of the magnitude or the frequency of the AC power outputted from the power conversion unit 130 to prevent the deterioration of the reception sensitivity of the electromagnetic wave due to the harmonic components.

Hereinafter, a description will be given of a technique for preventing the control unit 140 from controlling the transformer unit 120 to deteriorate the reception sensitivity.

7 is a view showing a transformer and a control unit according to an embodiment of the present invention.

Referring to FIG. 7, the transformer 120 may include a transformer 121, a control unit 122, and a distributor 123.

Although the distributor 123 is illustrated as being included in the transformer 120 in the drawing, the present invention is not limited thereto and may be configured separately.

The control unit 122 is capable of regulating the output voltage of the transformer 121 and can control an error of the output voltage by receiving a divided voltage of the output voltage of the transformer 121.

The distribution unit 123 may divide the output voltage of the transformer 121 and supply the voltage to the control unit 122.

The control unit 122 provides a pulse width modulation (PWM) whose pulse width is adjusted based on the voltage distributed from the distribution unit 123 to the transformer 121 and the transformer 121 generates a pulse of a square wave pulse It is possible to output a constant DC voltage whose level is adjusted according to the width.

The distribution unit 123 may be connected to an output control port (OUP) of the control unit 140.

The control unit 140 may control an output voltage of the transformer 121 by adjusting a value of an input terminal voltage of the control unit 122.

8 is a diagram illustrating a subsystem of a control unit according to an embodiment of the present invention.

8, the subsystem of the control unit 122 may include an error amplifier 124, a comparator 125, and a switch driver 126.

The error amplifier 124 amplifies the error of the output voltage Vout of the transformer 121 based on the distribution voltage Vd of the distribution unit 123 and outputs the amplified voltage Vc.

The output voltage of the transformer 121 is applied to the inverting terminal of the operational amplifier through the voltage divider 123 and the output voltage of the operational amplifier OP1 is applied to the non- The voltage Vref is applied.

The error amplifier 124 compares the output voltage of the transformer 121 through the voltage divider 123 with the reference voltage Vref, amplifies the error, and inputs the amplified error to the comparator 125.

The comparator 125 generates a square wave pulse based on the output voltage Vc of the error amplifier 124.

The comparator 125 may be composed of a second operational amplifier OP2. The output voltage Vc of the error amplifier 124 is applied to the non-inverting terminal, and the triangular wave is applied to the inverting terminal.

The comparator 125 compares the triangle wave with the output voltage Vc of the error amplifier 124 to generate a square wave pulse for driving the transformer 121 and outputs a pulse width corresponding to the output error of the transformer 121 The output voltage Vout of the transformer 121 can be stabilized.

The switch driver 126 may drive the transformer 121 based on the output of the comparator 125. That is, the predetermined voltage of the transformer 121 can be kept constant by controlling the ON and OFF of the switches included in the transformer 121.

The control unit 122 and the transformer 121 may be integrated into an integrated circuit (IC) by the transformer 120.

As such, the transforming unit 120 may output a constant voltage reflecting the error of the predetermined voltage. However, if the output voltage of the transformer 120 needs to be changed, the control unit 140 controls the transformer 120. FIG.

The distribution unit 123 includes a first resistor R1 connected to the output terminal of the transformer 121 and an input terminal (inverting terminal) of the error amplifier 124 and an input terminal (inverting terminal) of the error amplifier 124 And a second resistor R2 connected between ground.

It is preferable that the magnitude relation between the first resistor R1 and the second resistor R2 is related to R1 <R2.

The distribution voltage Vd of the transformer 121 may vary according to the values of the first and second resistors R1 and R2. The principles of the first and second resistors R1 and R2 are as follows. The divided voltage Vd obtained by dividing the output voltage Vout of the differential amplifier 121 is compared with the reference voltage Vref and the error is amplified so that when the divided voltage Vd is smaller than the reference voltage Vref, ) Rises to the ratio of the input resistance Rin of the error amplifier 124 to the feedback resistance Rf, i.e., the slope of? F / Rin. On the other hand, when the divided voltage Vd is larger than the reference voltage Vref, the output Vc level of the error amplifier 124 goes down to the slope of? F / Rin.

As described above, the divided voltage Vd may be fixed according to the values of the first and second resistors R1 and R2, but the output voltage of the transformer 121 may be finally adjusted by adjusting the divided voltage Vd.

This role can be handled by the control unit 140.

That is, the control unit 140 needs to adjust the output voltage Vout of the transformer 121 according to the power transmission environment between the transmitting apparatus 100 and the receiving apparatus 200. Further, when the reception sensitivity information of the receiving apparatus 200 is detected, it is necessary to lower the level of the output voltage of the transformer 121 when the reception sensitivity is low.

Since the third resistor R3 is connected between the output control port OCP of the control unit 140 and the input terminal of the error amplifier 124 (inverted terminal), the voltage output to the output control port OCP The divided voltage Vd applied to the input terminal of the error amplifier 124 can be adjusted.

The value of the divided voltage Vd can be changed under the control of the controller 140 and the output Vc of the error amplifier 124 based on the comparison of the divided voltage Vd with the reference voltage Vref Up or down state of the battery can be controlled.

When the output Vc of the error amplifier 124 is compared with the triangular wave of the comparator 125 so that the level of the output Vc of the error amplifier 124 rises, the comparator 125 compares the square wave with the increased pulse width When the level of the output Vc of the error amplifier 124 falls, the comparator 125 generates a square wave having a reduced pulse width.

On the other hand, the magnitude relation of the first to third resistors R1, R2, and R3 may be such that R1 <R3 <R2.

In this way, the control unit 140 can adjust the output voltage of the transforming unit 120 according to the receiving sensitivity of the receiving apparatus 200, and generates an AC power based on the DC voltage output from the transforming unit 120 The harmonic component of the output signal of the power conversion unit 130 can also be adjusted.

The harmonic components according to the rectangular wave signals for controlling the switching elements S1 to S4 of the power conversion unit 130 are determined by the characteristics in which the DC voltage applied to the power conversion unit 130 is proportional to the characteristics of the switching elements S1 to S4, The harmonic component is adjusted by using the change of the harmonic component according to the duty ratio of the square wave signal for controlling the reception device 200 so that the reception sensitivity of the communication system of the reception device 200 is lowered, It can be maintained at an appropriate level and the reliability of the user can be increased.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Wireless power transmission system (10)
The transmitting apparatus 100,
Transmit power converter system 101
The transmit antenna system 102,
The transformer 120,
Power conversion unit 130,
The control unit 140,
Side communication unit 141,
The RSSI detecting unit 142 detects,
The matching unit 150,
The selection unit 160 selects,
The receiving device 200,
The received power converter system (201)
The matching unit 210,
The rectifying part (220)
The receiving-side transformer 230,
The load (240)
The receiving-
Side communication unit 251,
Transformers (121)
The control unit 122,
The distribution unit 123,
The switch driver 126,

Claims (20)

A transmitting device for transmitting wireless power; And
And a receiving device for receiving the wireless power,
And controls the wireless power transmission amount according to the data reception sensitivity detected from the reception device. The method according to claim 1,
The transmitting apparatus includes:
Power supply;
A transformer for converting the power applied from the power supply unit into a DC power; And
And controlling the magnitude of the DC power according to the data reception sensitivity. The method according to claim 1,
The transmitting apparatus includes:
Power supply;
A transformer for converting the power applied from the power supply unit into a DC power;
A power converting unit for generating an AC power based on the DC power supplied from the transforming unit; And
And a controller for controlling at least one of a magnitude and a frequency of the AC power according to the data reception sensitivity. The method according to claim 3 or 4,
Wherein the transmitting apparatus further comprises an RSSI (Receive Sensitivity Information) detecting unit for detecting the data receiving sensitivity. 5. The method of claim 4,
The RSSI detection unit transmits a reception sensitivity detection signal to the reception apparatus,
Wherein the receiving apparatus detects the data reception sensitivity of the receiving apparatus according to the receiving sensitivity detection signal and provides the detected receiving sensitivity to the RSSI detecting unit. 3. The method of claim 2,
And compares the data reception sensitivity with a preset value, and adjusts the size of the direct current power accordingly. 6. The method of claim 5,
Wherein the receive sensitivity detection signal occurs periodically. The method according to claim 1,
The transmitting apparatus includes:
Further comprising: a storage device that tabulates and stores a wireless power transmission amount corresponding to the detected data reception sensitivity. A wireless power transmission apparatus for transmitting wireless power to a receiving apparatus,
The wireless power transmission apparatus comprising:
And controls a wireless power transmission amount according to a data reception sensitivity of the reception device. 10. The method of claim 9,
The wireless power transmission apparatus comprising:
And an RSSI detecting section for detecting the data receiving sensitivity. 11. The method of claim 10,
The wireless power transmission apparatus comprising:
Power supply; A transformer for converting the power applied from the power supply unit into a DC power; And a controller for controlling a magnitude of a DC power supply of the transforming unit,
Wherein the control unit adjusts the size of the DC power supply according to the data reception sensitivity from the RSSI detection unit. 10. The method of claim 9,
And compares the data reception sensitivity with a preset value to adjust the size of the direct current power accordingly. 11. The method of claim 10,
The RSSI detection unit transmits a reception sensitivity detection signal to the reception apparatus,
Wherein the receiving apparatus detects the data receiving sensitivity of the receiving apparatus according to the receiving sensitivity detection signal and provides the detected receiving sensitivity to the transmitting apparatus. 14. The method of claim 13,
And the reception sensitivity detection signal periodically occurs. A transmitting device for transmitting wireless power; And a receiving device for receiving the wireless power, the method comprising:
A method of driving a wireless power transmission system,
The transmitting apparatus transmitting wireless power according to an amount of power required by the receiving apparatus;
The transmitting apparatus transmitting the receiving sensitivity detection signal to the receiving apparatus;
Detecting a data reception sensitivity according to the reception sensitivity detection signal and providing the detection result to the transmission apparatus; And
And the transmitting device compares the data reception sensitivity with a preset value and controls a wireless power transmission amount according to the comparison result
A method of driving a wireless power transmission system. 16. The method of claim 15,
And if the data reception sensitivity is lower than the preset value, lowering the amount of wireless power transmission. 16. The method of claim 15,
Wherein the reception sensitivity detection signal is generated periodically. 16. The method of claim 15,
Wherein the transmitting apparatus transmits the radio power according to a required power amount of the receiving apparatus,
The receiving apparatus requesting a first power; And
And transmitting the second power by the transmitting apparatus. 19. The method of claim 18,
Wherein the transmitting device compares the data reception sensitivity with a preset value and controls a wireless power transmission amount according to the comparison result,
When the data reception sensitivity is lower than a predetermined value, transmitting the third power,
And transmitting a first power when the data reception sensitivity is higher than a preset value. 20. The method of claim 19,
Wherein the first power is greater than the second power and the second power is greater than the third power.

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