KR20200005151A - Method and apparatus for wireless power transfer capable through automatic adjusting of transmission power - Google Patents

Abstract

The present invention relates to a wireless power transmission and reception balancing method through automatic adjustment of a transmission power intensity and a device thereof. If a plurality of loads are to be charged by transferring power to the plurality of loads through wireless power transmission, the power for the power transmission to each wireless power receiver from a wireless power transmission device is uniformly adjusted or the transmission power intensity is effectively adjusted in accordance with needs of a power reception side.

Description

TECHNICAL AND APPARATUS FOR WIRELESS POWER TRANSFER CAPABLE THROUGH AUTOMATIC ADJUSTING OF TRANSMISSION POWER}

The present invention relates to a wireless power transmission and reception balancing method and apparatus through automatic adjustment of the transmission power strength, and more particularly, in a wireless power transmission apparatus to transmit and charge power to a plurality of loads through wireless power transmission. The present invention relates to a method and an apparatus for efficiently performing wireless charging by adjusting power for power transmission to each wireless power receiver equally or by adjusting the intensity of transmission power according to the needs of the power receiver.

Recently, the development of the Internet has made a leap, and as the spread of portable terminals has exploded, there are many cases where multimedia contents are transmitted and received by accessing the high-speed Internet using a portable terminal. Accordingly, power consumption for downloading and playing multimedia contents is increasing in portable terminals. In the battery power of the portable terminal, there is a limit to enjoying multimedia contents for a long time, and a lot of cases of using a secondary battery have occurred.

Therefore, users of portable terminals frequently carry extra auxiliary batteries. However, the secondary battery also needs to be charged in advance to be used when needed, so users should also care for the charger. In addition, if you do not take care of the auxiliary battery with care, you may not be prepared for the discharge of the mobile terminal.

The present invention is to solve this cumbersome problem, and to provide a method and apparatus for automatically charging the user of the portable terminal by simply placing the secondary battery near a predetermined wireless power transmission base station.

In particular, in automatically charging the auxiliary battery, the power of the transmission power for wireless power transmission is balanced so that the plurality of portable auxiliary batteries can be evenly and quickly charged.

Wireless power transfer is a term commonly applied to various technologies for transferring energy using an electromagnetic field. In the case of using inductive coupling, a magnetic field is generated between wire coils to transfer power. Resonant Induction Coupling is a kind of inductive coupling in which power is transmitted by a magnetic field between two resonant circuits. Capacitive Coupling transfers power by an electric field between electrodes such as metal plates.

On the other hand, various wireless charging is possible according to the application field. First, in the case of charging wirelessly in a fixed environment, the wireless charger only charges to a terminal that is recognized and does not charge a terminal that is not recognized. That is, when you want to use the wireless charging function of the terminal in the home or office, it is necessary to register in advance. In order to provide a charging function for a new terminal, a procedure for registering a wireless charger in a home is required, and an identifier for identifying the terminal is generated during registration.

In addition, when charging a plurality of terminals at the same time, the charger of the wireless power transmission device can charge a plurality of wireless charging terminals at the same time. It is possible to charge each terminal by rotating it little by little. At this time, each terminal can be charged with a charging parameter by different wireless power transmission. In order to realize this, each terminal is charged for a predetermined time, but when charging to the next terminal, it is necessary to reset the value according to the wireless power transmission for the terminal. In this manner, it is possible to wirelessly charge all terminals within a certain range evenly.

In addition, when wireless charging is performed on the sensor, since the sensor is used in various environments for various purposes, it is possible to use the sensor in the farm to analyze the state of agricultural products, and also use the sensor in water and sewage, power lines, and gas pipes. Problems can be analyzed, or operation status can be identified. In addition, the human body can be used to confirm the state of health. But the biggest problem with sensors is how to manage the battery. In particular, underground sensors are almost impossible to recharge. So, in the case of sensors, wireless charging technology can have a very big effect.

In addition, when wireless charging is desired in public places, various types of portable electric devices have emerged, and many people use them when carrying and moving in public places. Typical portable devices include smart phones, radios, cameras, laptops, medical devices, and the like. If the wireless power transmission service is provided in public places, you do not have to worry about the remaining battery capacity of the portable device when going out, and can receive the power charging service anytime and anywhere. Representative places to receive power charging are available at bus stops, train stations, buses or trains, restaurants and coffee shops where people can wait a considerable amount of time.

In addition, if you want to wireless charging for a temporary period, commercial areas such as cafes and restaurants can provide a free wireless power transfer charging service for customers. At this time, the owner can provide a wireless charging access code that can be used by the customer. Here, there is a free recharge service that the customer can use while preparing food / drink as a person ordering food or drink. The access code is a code that can be used temporarily for a period of time set by the owner, and the owner needs a database to manage the access code.

There is also a service for charging electric vehicles in public places. Electric vehicles are mainly used in public charities. Since the amount of electricity used is larger than that of other terminals, it is expensive to charge. People usually park their cars in public parking lots such as shopping centers, restaurants, coffee shops, commercial districts and tourist attractions. Therefore, it is very efficient to provide electric charging service wirelessly in public parking. Wireless charging is very convenient for both the user and the car, and the user can control the charging time and the amount of charge.

It is also a case of drone charging service. In recent years, drones have been widely used, especially on farms and ranches, which can be effectively used to monitor livestock and crops scattered over a wide range and to spray fertilizers and pesticides. The National Park Service, for example, can be used to understand the state of the park and to rescue people or animals that have had an accident. It can be used by police for security surveillance and road patrols, and in movies when filming landscapes. Because drones fly over large areas, they consume a lot of power.

Among the various application fields described above, the present invention, when charging a plurality of terminals at the same time in a fixed environment or a limited mobile environment with a certain range, when charging a plurality of wireless charging terminals at the same time in a wireless power transmission device, the load By adjusting the power to transfer power to the load automatically according to the change of, the transmitter can adjust the intensity of power transmission for charging automatically according to the requirements of the receiver or the situation of the receiver. I want to.

Next, the prior art existing in the technical field of the present invention will be briefly described, and then the technical matters to be made differently from the prior art will be described.

First, International Patent Publication No. WO2017-034154 A1 (2017.03.02.) Relates to a wireless power transmission apparatus and a control method thereof, including: a first sensor sensing a position of the receiver on a charging pad, and at least one corresponding to the position of the receiver. The multiplexer for multiplexing and supplying power to the wireless power transmitter of the power is controlled based on the power transmission efficiency for each of the at least one wireless power transmitter.

In the prior art, the power is controlled based on the power transmission efficiency, and the higher the efficiency index is, the higher the quality index Q = (WL / R). In another embodiment, the power control of the wireless power transmitter may be performed by measuring the strength of the current on the receiving side and feeding it back to the transmitting side.

Therefore, the prior art is to perform the power control according to the power transmission efficiency and the strength of the current of the receiving side, the present invention checks the current flowing from the power transmitting side directly to the power receiving side to determine the situation of the receiving side and the power control As it is to be carried out, the differences between the two inventions are obvious.

In addition, Korean Patent Publication No. KR20180019729A (February 26, 2018) relates to a technology for handoff and load balancing of a wireless power transmission system, and loads a wireless power receiver client through a plurality of wireless power transmission systems in a wireless power transmission environment. We present balancing technique.

The prior art relates to the load balancing of the wireless power transmission system, to detect the load imbalance between the at least two wireless power transmission system based at least in part on the transmitter load information, to improve the load imbalance, the wireless power of the present invention There is a distinction between the technical characteristics and the automatic adjustment of the transmit power intensity to be transmitted to the load by measuring the state of the load on the transmitting side and using it.

One embodiment of the present invention was created to solve the above problems, and an object of the present invention is to provide an efficient wireless charging method and apparatus through automatic adjustment of the transmission power strength in wireless power transmission.

In addition, the present invention is to equalize by adjusting the power for the power transmission from the wireless power transmitter to each wireless power receiver when charging to transmit power to a plurality of loads through the wireless power transmission, or needs of the power receiving side The purpose of the present invention is to provide a method and apparatus for efficiently performing wireless charging by adjusting the intensity of a transmission power.

In addition, the present invention measures the current flowing to the load by the wireless power transmitter in order to respond to changes in the state of the various loads in the wireless power transmitter, and then analyze the numerical value of the current to the strength of the power to be transmitted to the wireless power receiver The purpose is to adjust.

Wireless power transmitter and receiver according to an embodiment of the present invention, the current measuring unit for measuring the current due to the power provided coupled to each of the plurality of wireless power receiver in the wireless power transmitter, the wireless power specified in the wireless power transmitter And a transmission power control unit for determining the strength of the transmission power using the measured current by the receiver, and a transmission power driver for driving the transmission power according to the determined strength of the transmission power.

Herein, the wireless power receiver includes a rectifier for receiving and rectifying the provided power through the coupling, a DC / DC converter for DC / DC converting the rectified voltage to provide power to a load, and a temperature at the wireless power receiver. Characterized in that it comprises a temperature sensing unit for measuring, and a current sensing unit for measuring the current flowing from the wireless power receiver to the load.

In addition, the transmission power control unit determines the strength of the transmission power by predicting the temperature of the wireless power receiver by the change rate of the absolute current intensity and the current intensity, the greater the change rate for both the intensity of the current and the intensity of the current In addition, the capacity of the load is determined to be large, the temperature rise of the wireless power receiver is predicted, and the current is controlled to flow less to the load or the wireless power receiver.

In addition, the transmission power control unit predicts the strength of the current to reach the future through the derivative as the rate of change with respect to the strength of the current is large, by predicting the temperature corresponding to the strength of the current, so as not to reach the temperature in advance Limiting the flow of current to prevent overheating in advance.

In addition, the transmission power control unit predicts the temperature of the wireless power receiver based on the temperature measured by the temperature detector of the wireless power receiver and the current detected by the current detector by the rate of change of the absolute current intensity and the current intensity. To determine the strength of the transmission power, the larger the rate of change of the current intensity and the current intensity, the greater the capacity of the corresponding load, and predicts the temperature rise of the wireless power receiver, the corresponding load or wireless power receiver It characterized in that the control to flow less current.

On the other hand, the wireless power transmission method according to another embodiment of the present invention, the current measurement step of measuring the current due to the power provided by coupled to each of the plurality of wireless power receiver from the wireless power transmitter, specific in the wireless power transmitter And a transmission power control step of determining the strength of the transmission power using the measured current with the wireless power receiver, and a transmission power driving step of driving the transmission power according to the determined transmission power strength.

The present invention proposes a wireless power transmission and reception balancing method and apparatus through automatic adjustment of the transmission power strength. In the case where it is desired to transfer and charge power to a plurality of loads through the wireless power transmission, the wireless power transmitter adjusts power for power transmission to each wireless power receiver to equalize or transmit power according to the needs of the power receiver. It is possible to efficiently perform the wireless charging by adjusting the intensity of the.

1 is a view showing a wireless power transmission and reception concept according to an embodiment of the present invention.
2 is a view showing a concept of a method and apparatus for efficiently performing wireless charging by automatically adjusting the transmission power strength from the wireless power transmitter to the wireless power receiver according to an embodiment of the present invention.
3 is a view for explaining a concept of controlling the transmission power strength to a plurality of wireless power receiver in a wireless power transmitter according to an embodiment of the present invention.
4 is a diagram illustrating a topology for connecting a wireless power transmitter and a plurality of wireless power receivers in a communication channel according to an embodiment of the present invention.
5 is a conceptual diagram of controlling the strength of the current in advance by predicting the temperature of the wireless power receiver in the wireless power transmitter according to an embodiment of the present invention.
6 is a block diagram showing the structure of a wireless power transmitter according to an embodiment of the present invention.
7 is a block diagram showing the structure of a wireless power receiver according to an embodiment of the present invention.
8 is a flowchart illustrating a wireless power transmission and reception process according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the preferred embodiment of the efficient wireless charging method and apparatus through the automatic adjustment of the transmission power strength in the wireless power transmission of the present invention. Like reference numerals in the drawings denote like elements. In addition, specific structural to functional descriptions of the embodiments of the present invention are only illustrated for the purpose of describing the embodiments according to the present invention, and unless otherwise defined, all terms used herein including technical or scientific terms These have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. It is preferable not to.

1 is a view showing a wireless power transmission and reception concept according to an embodiment of the present invention.

As shown in FIG. 1, the concept of wireless power transmission and reception is that when the wireless power transmitter 100 included in the power transmission unit transmits power through an antenna or a coupling device 10, an antenna or coupling provided in the power reception unit is included. The wireless power receiver 200 receives the power through the device 20 and delivers the power to the load 30.

For example, in the case of resonant power transmission, the wireless power transmitter 100 rectifies and receives commercial power (Vs) (100V or 200V), converts the rectified power into a high frequency power, and forms a resonance circuit to form an antenna ( Or a resonant coil) or a coupling device to transmit high frequency power. The high frequency power passes through the antenna or the coupling device to achieve resonance coupling with the receiving antenna or the coupling device. When the resonance is formed, a voltage several times as large as that provided can be delivered to the receiving side. The wireless power receiver 200 on the receiving side regulates and rectifies the resonant voltage appropriately, converts it into a voltage required by the load, and then supplies power to the load.

The distance between the wireless power transmitter 100 and the wireless power receiver 200 depends on the size and direction of the antenna or coupling device. In the case of resonant power transmission, the distance may vary depending on the size of the antenna, It is possible to transfer power to the product.

According to the coupling principle between the wireless power transmitter 100 and the wireless power receiver 200, transmission and reception of power by resonance, inductive coupling or electrostatic coupling is possible. Therefore, the corresponding coupling device must be provided as required. That is, it is possible to transmit and receive power by means including resonance, inductive coupling, electrostatic coupling, or a combination thereof.

Accordingly, in the present invention, power may be transmitted in at least one of capacitive, inductive coupling, or electrostatic coupling. In the case of inductive coupling, since a coil is formed at a close distance between a transmitter and a receiver, power is transmitted, and therefore, the transmitter and the receiver should be located very close together. On the other hand, the resonant type is configured to form a resonant circuit between the transmitter and the receiver through a coil or an antenna, and it is possible to transmit and receive power while maintaining a considerable distance depending on the size of the antenna or the coil. Therefore, the resonant power transfer technique has excellent scalability in distance. On the other hand, in the case of electrostatic coupling, a metal plate is installed between the transmitter and the receiver to form an electric field between both metal plates, through which power is transmitted and received.

Therefore, the power transmission and reception apparatus may be configured by selecting any one of capacitive, inductive coupling, or electrostatic coupling according to an environment or efficiency to transmit and receive power.

Hereinafter, a method of adjusting the strength of the transmission power between the wireless power transmitter and the wireless power receiver according to the present invention will be described.

2 is a view showing a concept of a method and apparatus for efficiently performing wireless charging by automatically adjusting the transmission power strength from the wireless power transmitter to the wireless power receiver according to an embodiment of the present invention.

As shown in FIG. 2, the wireless power transmitter 100 and the wireless power receiver 200 have a communication function, and correspond to the state of charge, current, or temperature of the load 30 in the wireless power receiver 100. The information is provided to the wireless power transmitter 100 so that the wireless power transmitter 100 determines the strength of the transmission power based on the information.

In FIG. 2 (a), a separate communication channel is provided between the wireless power transmitter 100 and the wireless power receiver 200 to determine the transmission power strength of the power transmitter according to the state of the power receiver.

On the other hand, as shown in Figure 2 (b), by monitoring how much current flows from the wireless power transmitter 100 to the wireless power receiver 200 itself, and then controlling the strength of the transmission power in accordance with the strength of the current Way. In this case, when the wireless power receiver 200 draws a lot of power by combining with a specific antenna or coupling device of the wireless power transmitter, the wireless power transmitter 100 monitors this and then moves toward the wireless power receiver 200. Can supply a lot of power, and control it to supply relatively low or normal levels of power otherwise.

If any one of the plurality of wireless power receivers 200 requires a lot of power, the receiver can be controlled to be charged in a short time by supplying a lot of power, but this must be done according to the logic of the control. no. If necessary, if the user requires fast charging with a control interface UI (User Interface), the power of the wireless power transmitter 100 may be set to a high intensity regardless of the strength of the current to supply a lot of power in a short time.

In the present invention, the wireless power receiver and the load may be integrated into one terminal to form a terminal, and a plurality of wireless power receivers may be configured to charge by connecting a rechargeable battery.

Therefore, when transmitting power from the wireless power transmitter to the wireless power receiver, the method of adjusting the strength of the transmission power receives the status information from the wireless power receiver through the communication means and adjusts it accordingly, and the wireless power transmitter determines itself. There is a method of controlling the strength of the transmission power. The self-determination is to measure the current flowing to the device coupled to the specific power receiver 200 to increase the environment for the power supply, that is, the strength of the power supplied when a large amount of current flows, if the current does not flow much, Lower the intensity relatively. However, if the speed of the power increases with the change of the current flow with time is large, increase the power of the power in proportion to it, and if the speed of the increase is small, the power does not increase.

Therefore, the strength of the supply power is determined according to the change of current with time. It monitors the strength of the current over time, differentiates the change, and then determines the strength of the power supplied according to the degree (tilt).

Hereinafter, a structure for supplying power to a plurality of loads through wireless power transmission and reception will be described.

3 is a view for explaining a concept of controlling the transmission power strength to a plurality of wireless power receiver in a wireless power transmitter according to an embodiment of the present invention.

As shown in FIG. 3, the wireless power transmitter 100 and the plurality of wireless power receivers 200 according to the present invention are coupled to each other to wirelessly supply power to a load in various forms such as radial, square, and straight lines. It is possible to arrange. Herein, the wireless power transmitter transmits power from a plurality of antennas or coupling devices, and in the plurality of wireless power receivers, the current is measured to convert the magnitude of power delivered to each antenna or coupling device, and receive If there is a lack of power, requesting further transmission, the wireless power transmitter 100 may determine the strength of the transmission power and provide the same according to the request. In this process, in order to supply power to the plurality of wireless power receivers 200, the strength of the transmission power is adjusted to ensure even charging. In other words, the transmission power is balanced.

On the other hand, by measuring the current flowing from the wireless power transmitter 100 to each of the wireless power receiver 200 increases the strength of the power when the current flows a lot, and relatively decreases the strength of the power. This adjustment to the power intensity can further determine the power intensity in proportion to how rapidly the current flow changes over time. In other words, if it changes rapidly, it is expected to consume a lot of power in the near future. Therefore, it supplies a lot of power in the near future. On the contrary, if there is not much current change, the power intensity is maintained at the previously supplied intensity or only slightly high or low. By changing, the strength of the transmission power is balanced.

In addition, when the wireless power transmitter and the plurality of wireless power receivers 200 are connected radially, squarely, and in a straight line to each other, how efficiently the communication means are arranged and connected is a very important issue. For example, when the wireless power receiver 200 is disposed radially, each wireless power receiver 200 is located close to each other when connected to the plurality of wireless power receivers 200, so that the wireless power receivers are RS-232 and RS. -485 can be bundled into a ring using a serial communication method, and only one wireless power transmitter 100 and the wireless power receiver 200 can be connected to each other by wired or wireless communication.

In this case, the wireless power receiver 200 may be tied to each other through the wiring, and by configuring one of the plurality of wireless power receiver 200 to communicate with the wireless power transmitter 100, each wireless communication module Since the power receiver 200 does not need to be provided, the wireless power transmitter can be configured at a low cost.

As described above, the wireless power transmitter 100 and the plurality of wireless power receivers 200 may be connected in a ring structure when disposed in a radial or quadrangular shape, and in the case of a straight line, a plurality of wireless power receivers 200 such as a bus. ) Can be connected. When connecting by bus, it is desirable to connect terminators at both ends of the bus.

Meanwhile, one wireless power transmitter 100 and a plurality of wireless power receivers 200 may be configured to be connected to a hub. In this case, since the wireless power transmitter and the wireless power receiver are connected to the hub, the handling and installation are very simple.

4 is a diagram illustrating a topology for connecting a wireless power transmitter and a plurality of wireless power receivers in a communication channel according to an embodiment of the present invention.

 As shown in Figure 4, in connecting the wireless power transmitter 100 and the plurality of wireless power receiver 200 according to the present invention, (a) between the wireless power transmitter 100 and the main wireless power receiver 200 To secure the communication channel, the remaining wireless power receiver 200 is in the form of tying in a cheap communication means. In this case, the wireless power receiver 200 is relatively close, and the communication line is connected between them by serial communication such as RS-232 or RS-485, and each wireless power receiver is recognized as one device. In addition, the wireless power transmitter and the plurality of wireless power receivers can be bundled in a communication channel at low cost.

(b) In addition, the wireless power transmitter 100 and the wireless power receiver 200 may be connected in a star-shaped manner, which is a very inefficient method. But it is very convenient to control. (c) Another method which is very convenient to connect the wireless power transmitter 100 and the plurality of wireless power receivers 200 has a hub, and connects the wireless power transmitter 100 and the wireless power receiver 200 to the hub. That's how. This method is simple to install and operate, and switches the hub to send and receive data between multiple ports. Therefore, additional devices such as hubs are needed.

(d) There is also a bus type, in which the wireless power transmitter and wireless power receiver are connected to the bus, in which case the wireless power transmitter and the wireless power receiver each transmit and receive data. Each node is identified and communicated with the ID assigned to the receiver.

As described above, when the power transmission and reception device is configured with a separate communication module, the device becomes complicated. Therefore, in the present invention, it is intended to minimize the communication module as much as possible. To this end, the measurement of the current is performed in the wireless power transmitter, and the state of the wireless power receiver is predicted therefrom to control the intensity of the transmission power to the corresponding receiver.

5 is a conceptual diagram of controlling the strength of the current in advance by predicting the temperature of the wireless power receiver in the wireless power transmitter according to an embodiment of the present invention.

As shown in Fig. 5, the intensity of the current changes with time. The intensity of the transmit power from the wireless power transmitter to the wireless power receiver is controlled from the absolute intensity of the current and the degree of change of the current.

Specifically, the wireless power transmitter includes a plurality of antennas or coupling devices. First, the current flowing to each antenna or coupling device is measured. The measured results are used to predict the state of the wireless power receiver coupled to the corresponding antenna or coupling device and the state of the load.

Predicting the state of a load connected to a particular wireless power receiver and the wireless power receiver is influenced by changes in the strength of the current flowing into them and the strength of the current.

If both the current intensity and the current intensity change is large, it is determined that the load capacity is large, thus increasing the possibility of overloading the wireless power receiver that delivers power to the load. In this case, the temperature rise of the wireless power receiver is expected, which is set by the temperature parameter depending on how much the difference is compared with the pre-stored rated load, and checks this to predict the temperature of the wireless power receiver.

The heat generated over time is numerically stored for the strength of the current flowing in the wireless power receiver. Accordingly, when it is predicted that the temperature rises high, the current is controlled to flow less to the load or the wireless power receiver.

In addition, it is possible to see the change of the current intensity, and the larger the change of the current, the more it is possible to predict the strength of the current to reach after a certain period of time through the derivative, so that the strength of the current is estimated in advance By predicting the temperature to be in advance and not reaching the temperature in advance, the current flow is limited to prevent overheating in advance. Of course, if the current intensity is reduced, there is no adverse effect on the wireless power receiver and the load, and thus it is not necessary to control the current intensity in a leading way.

Next, each operation will be described from a detailed block diagram of the wireless power transmitter and the wireless power receiver according to the present invention.

6 is a block diagram showing the structure of a wireless power transmitter according to an embodiment of the present invention.

As shown in FIG. 6, the wireless power transmitter 100 includes a transmission power driver 110, an amplifier 120, a controller 130, a wired / wireless communication unit 140, a power measurement unit 150, and a current measurement unit ( 160). Coupling device 10 may be further provided here.

First, the transmission power driver 110 performs a function of rectifying commercial power Vs in the wireless power transmitter 100 to switch at high frequency and outputting the same. And the like.

The amplifying unit 120 determines a parameter to control the current measured by the current measuring unit 160 through the transmission power control unit 150, and the amplifying unit 120 in the transmission power driver 110 as the control parameter. Control the amplification degree.

The controller 130 controls the result of communicating with the user through the wired / wireless communication unit 140 and the result of communicating with the wireless power receiver 200 through the transmission power driver 110.

The control unit 130 may be a part that performs a function similar to the transmission power control unit 150 by reflecting the temperature, current, and user requirements provided from the wireless power receiver 200. If a communication channel is secured between the wireless power transmitter 100 and the wireless power receiver 200, the temperature can be measured directly by the wireless power receiver 200, and thus a separate prediction process is not required. The strength of the transmission power may be controlled by reflecting requirements such as the temperature and current measured at 200 or the user's charging time.

The current measuring unit 160 measures the current flowing from the coupling device 10 to the coupling device 20 of the wireless power receiver 200 between the amplifier 120 and the coupling device 10. As a result, transmission power control is performed through the transmission power control unit 150.

As described above with reference to FIG. 5, the transmission power control determines the power to be controlled by the amplifier based on the change rate of the current intensity and the current intensity.

7 is a block diagram showing the structure of a wireless power receiver according to an embodiment of the present invention.

As shown in FIG. 7, the wireless power receiver 200 includes a rectifier 210, a DC / DC converter 220, a controller 240, a temperature / current detector 250, and a wired / wireless communication unit 230. It is composed. In addition, the device may further include a filling device 20.

When power is received from the wireless power transmitter 100 through the coupling device 20, for example, in the case of the resonance type, the voltage due to resonance is driven very high. The input resonated by the high frequency alternating current is rectified through the rectifier 210 and then lowers the high voltage through the DC / DC converter 220 and then supplies it to the load 30. When the load is a charger, the power is charged to the load through the DC / DC converter 220.

The control unit 240 receives the user's requirements through the wired and wireless communication unit 230, and provides the wireless power transmitter 100 with the result measured by the temperature / current detection unit 250, the wireless power transmitter 100 To control the strength of the transmit power. In addition, the control unit 240 may control to block the check if the overvoltage is induced in the rectifier 210 and the DC / DC converter 220.

8 is a flowchart illustrating a wireless power transmission and reception process according to an embodiment of the present invention.

As shown in FIG. 8, in the wireless power transmission and reception process, first, if a condition for wireless power transmission is provided by a user, control is performed accordingly, and the specific wireless power receiver 200 in the wireless power transmitter 100 is performed. The transmission power to be controlled is determined by measuring the current flowing in the circuit, and the driving power is controlled by determining the power to be amplified by the amplifier.

That is, the current due to the power provided coupled to each of the plurality of wireless power receivers in the wireless power transmitter is measured (S100).

Herein, the process of determining the transmission power to be controlled and controlling the degree of amplification is as shown in FIG. 5 (S200).

That is, in the wireless power transmitter, the strength of the transmission power is determined using the measured current with the specific wireless power receiver, and the temperature of the wireless power receiver is predicted by the rate of change of the absolute current and the strength of the current. Decide on the strength. The larger the rate of change of the current intensity and the current intensity is, the larger the capacity of the load is determined, the temperature rise of the wireless power receiver is predicted, and the current flows to the corresponding load or the wireless power receiver. S200). Subsequently, the transmission power is driven according to the determined strength of the transmission power (S300).

The transmitted power is received by the wireless power receiver 200 again, rectified and DC / DC converted and then provided to the load.

In this process, the control unit 240 of the wireless power receiver 200 collects the temperature / current measurement result and the charging requirements (charging time, etc.) of the user received through the wired / wireless communication unit 230 from the wireless power transmitter 100. To provide. In this process, the control unit 240 may control to block the overvoltage when the rectifier 210 and the DC / DC converter 220 is induced.

As described above, the present invention is to provide an efficient wireless charging method and apparatus through automatic adjustment of the transmission power strength in wireless power transmission. In the case where it is desired to transfer and charge power to a plurality of loads through the wireless power transmission, the wireless power transmitter adjusts power for power transmission to each wireless power receiver to equalize or transmit power according to the needs of the power receiver. It is possible to efficiently perform the wireless charging by adjusting the intensity of the.

Although the above has been described above with reference to a preferred embodiment according to the present invention, the technical idea of the present invention is not limited thereto, and each component of the present invention is changed or modified within the technical scope of the present invention for achieving the same object and effect. Could be.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the above-described specific embodiment, the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

100: wireless power transmitter 200: wireless power receiver
10, 20: coupling device 30: load
110: transmission power driver 120: amplifier
130: control unit (wireless power transmitter) 140, 230: wired and wireless communication unit
150: transmission power control unit 160: current measurement unit
210: rectifier 220: DC / DC converter
240: control unit (wireless power receiver) 250: temperature / current detection unit

Claims (10)

A current measuring unit for measuring a current due to the power provided coupled to each of the plurality of wireless power receivers in the wireless power transmitter;
A transmission power control unit which determines the strength of transmission power by using the current measured by the wireless power receiver in the wireless power transmitter; And
And a transmission power driver for driving transmission power according to the determined transmission power strength. The method according to claim 1,
The wireless power receiver,
A rectifier for receiving and rectifying the provided power through the coupling;
A DC / DC converter for providing power to a load by converting the rectified voltage into DC / DC;
A temperature sensor for measuring a temperature in the wireless power receiver; And
And a current detector for measuring a current flowing from the wireless power receiver to the load. The method according to claim 1,
The transmission power control unit,
The strength of the transmission power is determined by predicting the temperature of the wireless power receiver using the absolute current intensity and the rate of change of the current intensity.
The larger the change rate of the current intensity and the current intensity, the greater the capacity of the load, the higher the temperature of the wireless power receiver is predicted, the less the current flows to the load or wireless power receiver. Wireless power transmission and reception device characterized in that. The method according to claim 3,
The transmission power control unit,
The greater the rate of change of the current intensity, the more predict the current intensity to reach the future through the differential, and predicts the temperature corresponding to the strength of the current, so as not to reach the temperature in advance, the current to prevent overheating in advance Wireless power transmission and reception device comprising the restriction of the flow of. The method according to claim 2,
The transmission power control unit,
Through the temperature measured by the temperature sensing unit of the wireless power receiver and the current sensed by the current sensing unit, the intensity of the transmission power is determined by predicting the temperature of the wireless power receiver based on the change rate of the absolute current intensity and the current intensity. But
The larger the change rate of the current intensity and the current intensity, the greater the capacity of the load, the higher the temperature of the wireless power receiver is predicted, the less the current flows to the load or wireless power receiver. Wireless power transmission and reception device characterized in that. The method according to claim 5,
The transmission power control unit,
The greater the rate of change of the current intensity, the more predict the current intensity to reach the future through the differential, and predicts the temperature corresponding to the strength of the current, so as not to reach the temperature in advance, the current to prevent overheating in advance Wireless power transmission and reception device comprising the restriction of the flow of. A current measuring step of measuring a current due to the power provided coupled to each of the plurality of wireless power receivers in the wireless power transmitter;
A transmission power control step of determining a strength of transmission power by using the current measured by the specific wireless power receiver in the wireless power transmitter; And
And a transmission power driving step of driving transmission power according to the determined transmission power strength. The method according to claim 7,
The transmission power control step,
The strength of the transmission power is determined by predicting the temperature of the wireless power receiver using the absolute current intensity and the rate of change of the current intensity.
The larger the change rate of the current intensity and the current intensity, the greater the capacity of the load, the higher the temperature of the wireless power receiver is predicted, the less the current flows to the load or wireless power receiver. Wireless power transmission and reception method characterized in that. The method according to claim 8,
The transmission power control step,
The greater the rate of change of the current intensity, the more predict the current intensity to reach the future through the differential, and predicts the temperature corresponding to the strength of the current, so as not to reach the temperature in advance, the current to prevent overheating in advance Wireless power transmission and reception method comprising the restriction of the flow of. The method according to claim 7,
The transmission power control step,
Through the temperature measured by the temperature sensing unit of the wireless power receiver and the current sensed by the current sensing unit, the intensity of the transmission power is determined by predicting the temperature of the wireless power receiver based on the change rate of the absolute current intensity and the current intensity. ,
The larger the change rate of the current intensity and the current intensity, the greater the capacity of the load, the higher the temperature of the wireless power receiver is predicted, the less the current flows to the load or wireless power receiver. Wireless power transmission and reception method characterized in that.

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