CN115276265A - Wireless charging system and method for selecting transmitting coil based on power reflection - Google Patents

Abstract

The invention relates to the field of wireless charging, in particular to a wireless charging system and method for selecting a transmitting coil based on power reflection. The system includes: a power supply; a power amplifier; a signal generator; a transmitting coil; a receiving coil; a monitoring circuit; The transmitter coil of the receiver coil, and the other transmitter coils are turned off. The present invention improves the receiving efficiency of the total transmitting power by opening the transmitting coil closest to the receiving coil and closing other transmitting coils, allocating the transmitting power to the open transmitting coil. The present invention can provide users with the best charging state by monitoring the reflected power data.

Description

A wireless charging system and method based on power reflection selective transmitting coil

technical field

The present invention relates to the technical field of wireless charging, in particular to a wireless charging system and method for selecting a transmitting coil based on power reflection.

Background technique

Wireless charging technology is currently a hot spot in new energy research. Magnetic resonance coupled wireless charging is the research focus of current wireless charging technology. In existing wireless charging systems, the transmitting end is usually one or more coils. In the case of multiple transmitting coils with the same specification and size, no matter where the receiving coil is in the traditional magnetic coupling wireless charging system, the coils at the transmitting end are generally turned on or off at the same time. Since the receiving efficiency of the receiving coil of a magnetic resonance coupled wireless charging system with a single transmitting coil is usually negatively correlated with its distance from the transmitting coil, in a magnetically coupled wireless charging system with multiple transmitting coils, the receiving coil and a certain transmitting coil In the case of facing directly, the receiving efficiency of the transmitting power of the transmitting coil is high, and the receiving efficiency of transmitting power of the transmitting coil not directly facing the receiving coil is not high.

For power transmission of rechargeable electronic devices, wireless charging has become a development trend due to the advantages of wireless charging technology such as convenience, safety, and strong versatility. For different working principles and application scenarios, there are different wireless charging technologies. At present, the wireless charging technologies that have been widely studied include electromagnetic induction, magnetic resonance coupling and microwave:

(1) Magnetic induction type: The magnetic induction type is based on the fact that a changing current flows through the transmitting coil, and the changing current generates a changing magnetic field. This magnetic field generates a current to the adjacent coil, thereby generating an induced electromotive force. However, due to the extremely limited charging distance of this method, only a few millimeters, it is only suitable for the device to be placed on the transmitter.

(2) Magnetic resonance coupling type: The magnetic resonance type is based on the principle of magnetic induction. Through the oscillation of the LC circuit, the transmitting device radiates the power, and the LC circuit system of the power receiving device realizes resonance at the same natural frequency, thereby realizing power reception. . In this way, the transmission distance can reach more than ten centimeters, and the equipment can move freely in a certain space, but it is too restricted.

(3) Microwave type: Microwave type converts environmental electromagnetic waves into electric current, and transmits current through the circuit. Although the distance of this microwave type wireless charging can reach kilometer level, the power stored in microwave is limited, only up to mW level, so only It can barely keep some low-power devices working, and is not suitable as a charging method for high-power devices.

The following disadvantages exist in the prior art including the above-mentioned wireless charging:

(1) Although the electromagnetic induction wireless charging technology is simple to implement and has a high conversion rate, it has defects in spatial movement due to the limitation of the charging distance of the charging method.

(2) The existing electromagnetic induction wireless charging equipment does not have the function of detection equipment. No matter where the receiving equipment is, all transmitting coils must continue to be in working state, resulting in the loss and waste of part of the power.

(3) The existing multi-transmitting coil technology usually turns on all the multi-transmitting coils. This technology distributes the transmitting power to each transmitting coil equally, so its energy-carrying electromagnetic wave field is fixed, and the receiving with the best receiving efficiency The device position is also fixed.

(4) Different wireless charging technologies have their own advantages and disadvantages. At present, most of the main wireless charging technologies on the market use the magnetic induction technology with QI as the standard. Although the implementation circuit of this technology is relatively simple, usually only a single coil is used, but it does not involve the selection of the transmitting coil.

Contents of the invention

Embodiments of the present invention provide a wireless charging system and method for selecting a transmitting coil based on power reflection, to at least solve the technical problem that the transmitting coil can automatically adjust the opening and closing of the transmitting coil according to the position of the receiving charging device.

According to an embodiment of the present invention, a wireless charging system for selecting a transmitting coil based on power reflection is provided, including: a power supply, a power amplifier, a signal generator, a monitoring circuit, a transmitting coil, a single-chip microcomputer and a receiving coil;

The power supply is used to provide a stable voltage for the system;

The signal generator is used to output the excitation signal to the power amplifier after being powered on;

The power amplifier is used to amplify the excitation signal output by the signal generator and transmit it to the transmitting coil to improve the power conversion rate and transmission distance;

The transmitting coil is used to transmit power to the receiving coil when the excitation signal is received;

The receiving coil is used to receive the power emitted by the transmitting coil and supply power to the device;

The monitoring circuit is used to monitor the reflected power returned by the transmitting coil in real time, convert part of the reflected power into a DC voltage signal readable by the microcontroller, and transmit the DC voltage signal to the microcontroller;

The single-chip microcomputer is used for judging the transmitting coil closest to the receiving coil after receiving the DC voltage signal, and keeping on the transmitting coil closest to the receiving coil and closing other transmitting coils according to the judgment result.

Further, the single-chip microcomputer includes:

The monitoring module is used to monitor the reflected power reflected from the transmitting coil to the monitoring circuit in real time;

The first judging module is used to judge whether the first preset condition is currently satisfied by monitoring the reflected power, and the first preset condition is that there is one and only one reflected power value within the first power value preset range;

The transmitting coil closing module is used to keep the transmitting coils meeting the first preset condition turned on if the first preset condition is met, and close other transmitting coils not satisfying the first preset condition, and the total transmitting power is all delivered to the opened transmitting coils. If the coil does not meet the first preset condition, it will maintain a continuous real-time monitoring state;

The second judging module is used to judge whether the reflected power value of the currently turned on transmitting coil satisfies the second preset condition, and the second preset condition is that the reflected power value of the currently turned on transmitting coil deviates from the second power value within a preset time The number of times in the preset interval is less than N;

The initialization module is used to keep the currently opened transmitting coil if the second preset condition is satisfied, and return to the initial real-time monitoring state if the second preset condition is not satisfied.

Further, the monitoring circuit includes a directional coupler and a logarithmic detector; the directional coupler is used to receive the reflected power returned by the transmitting coil, and the logarithmic detector is used to convert part of the power received by the directional coupler into a DC voltage signal readable by the microcontroller and Transmit this signal to the microcontroller.

Further, the system also includes:

A switch circuit, the switch circuit includes a plurality of relays for controlling corresponding transmitting coils; the switching circuit is connected with a single chip microcomputer, and the single chip microcomputer controls the on and off of the relays, thereby controlling the power amplifier and the transmitting coil on and off.

Further, the signal output by the signal generator is a 6.78MHz excitation signal.

Further, a resonant coil is arranged on the transmitting coil, and the natural frequency of the resonant coil is controlled between 6.78MHz±15kHz, and the transmitting coil generates resonance and transmits power after inputting an excitation signal.

Further, the number of transmitting coils is six, and the six transmitting coils form a cuboid shape, the top and bottom surfaces of the cuboid are square resonant coils, the four sides of the cuboid are rectangular resonant coils and the dimensions of the transmitting coils are the same.

Further, the system further includes a voltage-stabilizing rectifier, and the receiving coil rectifies the received power through the voltage-stabilizing rectifier to output a stable DC voltage.

According to another embodiment of the present invention, a wireless charging method for selecting a transmitting coil based on power reflection is provided, comprising the following steps:

The system receives the start command, and the start command includes at least a power-on signal;

When the power-on signal is received, the signal generator generates an output excitation signal and outputs it to the power amplifier;

When the excitation signal is received, the power amplifier amplifies the excitation signal output by the signal generator and transmits it to the transmitting coil to improve the power conversion rate and transmission distance;

When the transmitting coil receives the excitation signal, the transmitting coil transmits power to the receiving coil;

The receiving coil receives the power transmitted by the transmitting coil and supplies power to the device;

Monitor the reflected power returned by the transmitting coil in real time, convert part of the reflected power into a DC voltage signal readable by the microcontroller, and transmit the DC voltage signal to the microcontroller;

When the single-chip microcomputer receives the DC voltage signal, it judges the transmitting coil closest to the receiving coil, and according to the judgment result, keeps the transmitting coil closest to the receiving coil turned on, and closes the other transmitting coils.

Further, after the single-chip microcomputer receives the DC voltage signal, it judges the transmitting coil closest to the receiving coil, and according to the judgment result, keeps turning on the transmitting coil closest to the receiving coil, and closing other transmitting coils includes the following steps:

Real-time monitoring of the reflected power returned by the transmitting coil;

Judging whether the first preset condition is currently satisfied by monitoring the reflected power, the first preset condition is that there is one and only one reflected power value within the first power value preset interval;

If the first preset condition is met, keep turning on the transmitting coil satisfying the first preset condition, turn off other transmitting coils that do not meet the first preset condition, and deliver the total transmitting power to the opened transmitting coil; If the preset conditions are met, the real-time monitoring status will be maintained;

Judging whether the reflected power value of the currently turned on transmitting coil satisfies the second preset condition, the second preset condition is that the number of times the reflected power value of the currently turned on transmitting coil deviates from the second power value preset interval within the preset time is less than N;

If the second preset condition is satisfied, the currently opened transmitting coil will be kept; if the second preset condition is not met, then the initial real-time monitoring state will be entered.

The wireless charging system and method for selecting a transmitting coil based on power reflection in the embodiment of the present invention includes: a power supply, used to provide power for the system; a signal generator, used to output an excitation signal to a power amplifier after power-on; a power amplifier used for The excitation signal output by the signal generator is amplified and transmitted to the transmitting coil to improve the power conversion rate and transmission distance; the transmitting coil is used to transmit power to the receiving coil when the excitation signal is received; the receiving coil is used to transmit power to the receiving coil based on the received The power emitted by the transmitting coil is used to supply power to the device; the monitoring circuit is used to monitor the reflected power reflected by the transmitting coil in real time, convert part of the reflected power into a DC voltage signal readable by the microcontroller, and transmit the DC voltage signal to the microcontroller; the microcontroller , which is used to judge the transmitting coil closest to the receiving coil after receiving the DC voltage signal, and turn on the transmitting coil closest to the receiving coil and turn off other transmitting coils according to the judgment result. The present invention judges which transmitting coil is away from the receiving coil by measuring the numerical value of the transmitting power of each transmitting coil when all the transmitting coils are energized and turned on, and turns on the transmitting coil closest to the receiving coil, and closes other transmitting coils. All the transmitting power is distributed to the turned-on transmitting coil, so as to improve the receiving efficiency of the total transmitting power. The invention can provide the user with the best charging state through the monitoring of reflected power data.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the principle diagram of the wireless charging system based on the power reflection selective transmitting coil of the present invention;

Fig. 2 is the schematic diagram that the single-chip microcomputer of the present invention selects to open the transmitting coil;

Fig. 3 is the schematic diagram of monitoring circuit of the present invention;

Fig. 4 is a flow chart of the wireless charging method based on the power reflection selection transmitting coil of the present invention;

Fig. 5 is the flow chart that single-chip microcomputer of the present invention selects to open transmitting coil;

Reference signs: 100-power supply, 200-switching circuit, 300-power amplifier, 400-monitoring circuit, 401-directional coupler, 402-logarithmic detector, 500-transmitting coil, 600-receiving coil, 700-stabilizing voltage Rectifier, 800-charging equipment, 900-signal generator, 110-single chip microcomputer, 111-monitoring module, 112 first judging module, 113-transmitting coil closing module, 114-second judging module, 115-initialization module.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

Example 1

According to an embodiment of the present invention, there is provided a wireless charging system based on power reflection to select the transmitting coil 500, see Figures 1 to 3, including: a power supply 100, a power amplifier 300, a switch circuit 200, a signal generator 900, and a monitoring circuit 400, transmitting coil 500, single-chip microcomputer 110 and receiving coil 600;

The power supply 100 is used to provide a stable voltage for the system;

A signal generator 900, configured to output an excitation signal to the power amplifier 300 after being powered on;

The power amplifier 300 is used to amplify the excitation signal output by the signal generator 900 and transmit it to the transmitting coil 500 to improve the power conversion rate and transmission distance;

The transmitting coil 500 is used to transmit power to the receiving coil 600 when the excitation signal is received;

The receiving coil 600 is used to receive the power transmitted by the transmitting coil 500 and supply power to the device;

The monitoring circuit 400 is used to monitor the reflected power returned by the transmitting coil 500 in real time, convert part of the reflected power into a DC voltage signal readable by the single-chip microcomputer 110, and transmit the DC voltage signal to the single-chip microcomputer 110;

The single-chip microcomputer 110 is used for judging the transmitting coil 500 closest to the receiving coil 600 after receiving the DC voltage signal, and keeping the transmitting coil 500 closest to the receiving coil 600 open and closing other transmitting coils 500 according to the judgment result.

The wireless charging system based on the power reflection selection transmitting coil 500 in the embodiment of the present invention includes: a power supply 100, which is used to provide a stable voltage for the system; a signal generator 900, which is used to output an excitation signal to the power amplifier 300 after being powered on; the power amplifier 300, for amplifying the excitation signal output by the signal generator 900 and transmitting it to the transmitting coil 500 to improve the power conversion rate and transmission distance; the transmitting coil 500 is used for transmitting power to the receiving coil 600 when the excitation signal is received; The receiving coil 600 is used to receive the power transmitted by the transmitting coil 500 to supply power to the device; the monitoring circuit 400 is used to monitor the reflected power returned by the transmitting coil 500 in real time, convert part of the reflected power into a DC voltage signal readable by the microcontroller 110, and The DC voltage signal is transmitted to the single-chip microcomputer 110; the single-chip microcomputer 110 is used to judge the transmitting coil 500 closest to the receiving coil 600 after receiving the DC voltage signal, and according to the judgment result, open the transmitting coil 500 closest to the receiving coil 600, and close other Transmitting coil 500. The present invention judges which transmitting coil 500 is away from the receiving coil 600 by measuring the numerical value of the return power of each transmitting coil 500 when all the transmitting coils 500 are energized and turned on, and turns on the transmitting coil 500 closest to the receiving coil 600, The other transmitting coils 500 are turned off, and all the transmitting power is distributed to the enabled transmitting coil 500, so as to improve the receiving efficiency of the total transmitting power. The invention can provide the user with the best charging state through the monitoring of reflected power data.

Further, the receiving coil 600 is used to receive the power emitted by the transmitting coil 500, so as to supply power to the charging device 800; in addition, when the receiving coil 600 receives the power emitted by the transmitting coil 500, the reflected power of the transmitting coil 500 is transmitted through the monitoring circuit 400. to the single-chip microcomputer 100; and then proceed to the next step of judging the transmitting coil closest to the receiving coil.

It should be noted that when the transmitting coil 500 and the receiving coil 600 cannot be fully coupled, the power emitted by the transmitting coil 500 cannot be completely absorbed by the receiving coil 600, so that part of the power from the receiving coil 600 will flow back to the reflecting coil 500, and this part of the return power is called is the reflected power; the phase of the reflected power returned by the transmitting coil 500 is different from the power emitted by the transmitting coil 500 , and the directional coupler 401 can separate it. Inter-coil coupling effects have an effect on the reflected power. The coupling effect between coils is related to factors such as the distance between coils, frequency and transmission power.

Further, the transmitting power and size specifications of each transmitting coil 500 are the same. Firstly, the value range of the reflected power of the transmitting coil 500 is determined through experiments when the receiving coil 600 is in different positions. When the system is turned on, by monitoring the value of the reflected power of the transmitting coil 500 of the same size and specification with the same transmitting power, it is judged which transmitting coil 500 the current receiving coil 600 is closest to, and thus the transmitting coil 500 closest to the receiving coil 600 is opened and closed. Other transmitting coils 500; after the other coils are closed, all the transmitting power is distributed to the opened transmitting coil 500 to improve the receiving efficiency of the total transmitting power; the receiving coil 600 receives the power transmitted by the improved transmitting coil 500, and transmits the power to an external charging device 800 to charge the charging device 800 .

In this embodiment, the single-chip microcomputer 110 includes:

A monitoring module 111, configured to monitor in real time the reflected power that the transmitting coil 500 returns to the monitoring circuit 400;

The first judging module 112 is used to judge whether the first preset condition is satisfied by the reflected power obtained by monitoring. The first preset condition is that there is one and only one reflected power value within the first power value preset range;

The transmitting coil closing module 113 is used to turn on the transmitting coil 500 satisfying the first preset condition and to close other transmitting coils 500 not satisfying the first preset condition if the first preset condition is met, and the total transmitting power is all delivered to the opening coil. If the transmitting coil 500 does not meet the first preset condition, then keep continuing the real-time monitoring state;

The second judging module 114 is used to judge whether the reflected power value of the currently turned on transmitting coil 500 meets the second preset condition, and the second preset condition is that the reflected power value of the currently turned on transmitting coil 500 deviates from the second preset time The number of times in the power value preset range is less than N;

The initialization module 115 is configured to keep the currently turned on transmitting coil 500 if the second preset condition is met, and return to the initial real-time monitoring state if the second preset condition is not satisfied.

First, determine the interval of the reflected power value of the receiving coil 600 returning to the transmitting coil 500 when the receiving coil 600 is at different positions from the transmitting coil 500 . When the system is turned on, monitor the value of the reflected power of the transmitting coil 500 through the monitoring module 111, judge which transmitting coil 500 the current receiving coil 600 is closest to, and thus open the transmitting coil 500 closest to the receiving coil 600, and close other transmitting coils 500; when the other transmitting coils 500 are turned off, the total transmitting power provided by the power supply 100 is delivered to the turned-on discovery coil and the total transmitting power is transmitted to the receiving coil 600, and the receiving effect of the receiving coil 600 is optimal at this time.

The monitoring module 111 monitors the reflected power reflected from the transmitting coil 600 to the monitoring circuit 400 in real time.

The first judgment module 112 sets a first preset condition to judge whether the reflected power value returned by the transmitting coil 500 satisfies the condition; the first preset condition is that there is and only one reflected power value is within the first power value preset interval; When the receiving coil 600 is at different positions from the transmitting coil 500, the interval of the reflected power value returned by the transmitting coil 500 is determined through experiments; the determined power value interval is used as the first power value preset interval.

After the system is started, when multiple transmitting coils 500 are turned on, each transmitting coil will return a power value, and multiple power values will be returned. When one and only one of the returned power values is within the preset range of the first power value Then, turn on the transmitting coil 500, and turn off other transmitting coils 500 not within the preset range of the first power value; otherwise, return to the monitoring module 111 to continue monitoring until the first preset condition is met.

Since the receiving and charging device 800 is not always in a constant position, considering the degree of freedom, after the first preset condition is satisfied, the second judging module 114 then judges whether the second preset condition is satisfied, and the second preset condition is the current The number of times that the reflected power value of the turned-on transmitting coil 500 deviates from the second power value preset interval within the preset time is less than N; at this time, the reflected power of the single turned-on transmitting coil 500 is monitored, and when the reflected power value Z If it leaves the interval C to D more than N times within a certain period of time T, it is determined that the position of the receiving coil 600 has changed at this time. The reflected power value Z is the returned power value when a single transmitting coil 500 is turned on after the other transmitting coils 500 are turned off. The number of preset intervals for two power values.

After the wireless charging system automatically adjusts and turns on the transmitting coil 500, if the number of times Z is separated from C to D within the preset time T is less than N times, the reflected power value Z is within a reasonable value range of C to D within a certain period of time, and a single transmitting coil 500 remains on, otherwise the second preset condition is not satisfied, the system restarts all transmitting coils 500 at the transmitting end, and returns to the initial monitoring state.

In an embodiment, the monitoring circuit 400 includes a directional coupler 401 and a logarithmic detector 402; the directional coupler 401 is used to receive the reflected power returned by the transmitting coil 600, and the logarithmic detector 402 is used to receive part of the power received by the directional coupler 401 Convert it into a DC voltage signal readable by the single-chip microcomputer 110 and transmit the signal to the single-chip microcomputer 110 .

The system first needs to measure the value range of the return power.

First, after the power supply 100 is turned on, the directional coupler separates the reflected power of the receiving coil 600 when it is working, and then obtains a numerically converted DC voltage value through a logarithmic detector. Get the value of reflected power on the device. Thus, when the transmission power is equally divided, the value range of the reflected power when the receiving coil 600 is facing a single transmitting coil 500 at a distance of x to y, and the value range when the transmitting coil 500 has no receiving coil 600 or the distance is not between x and y , take the non-overlapping interval between the transmitting coil 500 and the receiving coil 600 as the numerical intervals A to B where the receiving coil 600 is facing the single transmitting coil 500 .

Secondly, with the same method as the first step, when the transmitting power is all concentrated on the resonant coil on the same transmitting coil 500, measure the range of reflected power when the receiving coil 600 is facing the transmitting coil 500 from x to y, and transmit When the coil 500 has no receiving coil 600 or the distance is not between x and y, take the non-overlapping interval as the numerical interval C-D of the transmitting coil 500 where the receiving coil 600 is facing the power-gathering coil 500 .

In an embodiment, the system also includes:

The switch circuit 200, the switch circuit 200 includes a plurality of relays that control the corresponding transmitting coil 500; the switch circuit 200 is connected to the single-chip microcomputer 110, and the single-chip microcomputer 110 controls the on-off of the relay, thereby controlling the on-off of the signal generator 900 and the power amplifier 300.

The wireless charging system works by inputting power through the power supply 100 and supplying operating voltage to the single-chip microcomputer 110 and the signal generator 900 at the same time. The signal generator 900 inputs a 6.78 MHz excitation signal to the power amplifier 300 so that the power amplifier 300 can work and transmit power. The power is input from the power supply 100 , passes through the switch circuit 200 , the power amplifier 300 , and the monitoring circuit 400 to the transmitting coil 500 . The switch circuit 200 is a control circuit including relays, and each relay controls a corresponding coil. According to the system response, the single-chip microcomputer 110 controls the working state of the triode to control the on-off of the relay, thereby controlling the on-off of the signal generator 900 and the power amplifier 300 .

In an embodiment, the signal output by the signal generator 900 is a 6.78 MHz excitation signal. The wireless charging system works by inputting power through the power supply 100 and supplying working voltage to the single-chip microcomputer 110 and the signal generator 900 at the same time. The signal generator 900 inputs a 6.78 MHz excitation signal to the power amplifier 300 .

In the embodiment, the transmitting coil 500 is provided with a resonant coil, and the natural frequency of the resonant coil is controlled between 6.78MHz±15kHz, and the transmitting coil 500 generates resonance and transmits power after an excitation signal is input. The resonant coil is composed of inductance and capacitance, the natural frequency is controlled at 6.78MHz±15kHz, and the amplified excitation signal is input to generate resonant emission radiation power.

In the embodiment, the number of transmitting coils 500 is six, and the six transmitting coils 500 form a cuboid shape, the top surface and the ground of the cuboid are square resonant coils, the four sides of the cuboid are rectangular resonant coils and the dimensions of the transmitting coils 500 are same. A three-dimensional resonant coil in the shape of a cuboid is composed of six resonant coils, and each side has a resonant coil. The top and bottom surfaces of the transmitting coil 500 are square resonant coils, and the four sides are rectangular resonant coils. The transmitting coil 500 selection function of the present invention is mainly applied to the four side coils of the same size and specification. The receiving coil 600 is a single resonant coil.

In the embodiment, the system further includes a voltage stabilizing rectifier 700, and the receiving coil 600 rectifies the received power through the voltage stabilizing rectifier 700 to output a stable DC voltage. The receiving coil 600 is connected to the voltage stabilizing rectifier 700 , the receiving coil 600 transmits the received power to the voltage stabilizing rectifier 700 , and after being rectified by the voltage stabilizing rectifier 700 , the power is transmitted to the charging device 800 .

The system has two working modes, including multi-coil monitoring mode and single-coil monitoring mode.

Multi-coil monitoring mode: when all the transmitting coils 500 at the transmitting end of the wireless charging system are turned on, the value of the reflected power of each transmitting coil 500 when all the coil switches of the MCU receiving system are turned on, if all the transmitting coils 500 are turned on, the reflected power of a certain transmitting coil 500 If the power value is in the interval A˜B, it is considered that the receiving coil 600 is at a distance x˜y from the transmitting coil 500 at the moment, that is, it is close to the transmitting coil 500 .

Single-coil monitoring mode: the total transmission power of the system is all delivered to the transmitting coil 500 closest to the receiving coil 600 . Since the receiving and charging device 800 is not always in a constant position, considering the degree of freedom, the reflected power of the single transmitting coil 500 is monitored at this time. Then it is determined that the position of the receiving coil 600 has changed at this time.

System workflow: connect the wireless charging system to the power supply 100, turn on the switches of all transmitting coils 500, and the wireless charging system enters the multi-coil monitoring mode. In the multi-coil monitoring mode, when the M microcontroller 110 detects the reflection When the power value is in the interval A-B, the system enters the single-coil monitoring mode for the transmitting coil 500 . In the single-coil monitoring mode, if the system determines that the position of the receiving coil 600 has changed, then the wireless charging system returns to the multi-coil monitoring mode to determine the transmitting coil 500 that the receiving coil 600 is facing.

The power of the wireless charging system is input by the power supply 100 , and transmitted to the transmitting coil 500 through the switch circuit 200 , the power amplifier 300 and the monitoring circuit 400 . The system judgment program is burned into the single chip microcomputer 110, receives the return value of the monitoring circuit 400 and compares it with the first measured power value range, outputs the judgment result in the form of high and low levels, and controls the switch circuit 200 to control the opening and closing of the coil.

Example 2

According to another embodiment of the present invention, a wireless charging method for selecting a transmitting coil based on power reflection is provided, see Figure 4 and Figure 5, the method includes steps:

S101: The system receives a startup instruction, and the startup instruction includes at least a power-on signal;

S102: When receiving the energization signal, the signal generator generates an excitation signal and outputs it to the power amplifier;

S103: When the excitation signal is received, the power amplifier amplifies the excitation signal output by the signal generator and transmits it to the transmitting coil to improve the power conversion rate and transmission distance;

S104: When the transmitting coil receives the excitation signal, the transmitting coil transmits power to the receiving coil;

S105: The power transmitted by the transmitting coil received by the receiving coil is used to supply power to the device;

S106: Monitor the reflected power returned by the transmitting coil in real time, convert part of the reflected power into a DC voltage signal readable by the microcontroller, and transmit the DC voltage signal to the microcontroller;

S107: After the single-chip microcomputer receives the DC voltage signal, it judges the transmitting coil closest to the receiving coil, and according to the judgment result, turns on the transmitting coil closest to the receiving coil, and turns off other transmitting coils.

In the wireless charging method based on power reflection selection of the transmitting coil in the embodiment of the present invention, the system receives the start command, and the start command includes at least a power-on signal; when the power-on signal is received, the signal generator generates an excitation signal and outputs it to the power amplifier After amplification; when the excitation signal is received, the power amplifier amplifies the excitation signal output by the signal generator and transmits it to the transmitting coil to improve the power conversion rate and transmission distance; when the transmitting coil receives the excitation signal, the transmitting coil transmits Output power to the receiving coil; the receiving coil receives the power transmitted by the transmitting coil and supplies power to the device; monitors the reflected power returned by the transmitting coil in real time, converts part of the reflected power into a DC voltage signal readable by the microcontroller, and converts the DC voltage signal Transmission to the single-chip microcomputer; when the single-chip microcomputer receives the DC voltage signal, it judges the transmitting coil closest to the receiving coil, and according to the judgment result, turns on the transmitting coil closest to the receiving coil and turns off other transmitting coils. The present invention judges which transmitting coil is away from the receiving coil by measuring the numerical value of the return power of each transmitting coil when all the transmitting coils are energized and turned on, and turns on the transmitting coil closest to the receiving coil and closes other transmitting coils. All the transmitting power is distributed to the turned-on transmitting coil, so as to improve the receiving efficiency of the total transmitting power. The invention can provide the user with the best charging state through the monitoring of reflected power data.

Further, the transmitting power and size specifications of each transmitting coil 500 are the same. Firstly, the value range of the reflected power of the transmitting coil 500 at different positions of the receiving coil 600 is determined through experiments. When the system is turned on, by monitoring the value of the reflected power of the transmitting coil 500 of the same size and specification with the same transmitting power, it is judged which transmitting coil 500 the current receiving coil 600 is closest to, and thus the transmitting coil 500 closest to the receiving coil 600 is opened and closed. Other transmitting coils 500; after the other coils are closed, all the transmitting power is distributed to the opened transmitting coil 500 to improve the receiving efficiency of the total transmitting power; the receiving coil 600 receives the power transmitted by the improved transmitting coil 500, and transmits the power to an external charging device 800 to charge the charging device 800 .

In the embodiment, after the single-chip microcomputer receives the DC voltage signal, it judges the transmitting coil closest to the receiving coil, and according to the judgment result, turning on the transmitting coil closest to the receiving coil and closing other transmitting coils includes the following steps:

S201: Real-time monitoring of the reflected power returned by the transmitting coil;

S202: Judging whether the first preset condition is currently satisfied by monitoring the reflected power, the first preset condition is that there is one and only one reflected power value within the first power value preset range;

S203: If the first preset condition is met, keep turning on the transmitting coil that meets the first preset condition, turn off other transmitting coils that do not meet the first preset condition, and deliver all the total transmitting power to the turned-on transmitting coil; The first preset condition is to maintain the continuous real-time monitoring state;

S204: Judging whether the reflected power value of the currently turned on transmitting coil satisfies the second preset condition, the second preset condition is that the reflected power value of the currently turned on transmitting coil deviates from the value within the preset interval of the second power value within a preset time The number of times is less than N;

S205: If the second preset condition is satisfied, keep the currently turned on transmitting coil; if the second preset condition is not met, go to the initial real-time monitoring state.

Firstly, when the receiving coil 600 is at different positions from the transmitting coil 500 , the range of the reflected power value of the transmitting coil 500 is determined. When the system is turned on, monitor the value of the reflected power of the transmitting coil 500 through the monitoring module 111, judge which transmitting coil 500 the current receiving coil 600 is closest to, and thus open the transmitting coil 500 closest to the receiving coil 600, and close other transmitting coils 500; when the other transmitting coils 500 are turned off, all the total transmitting power provided by the power supply is delivered to the enabled transmitting coil 500 and the total transmitting power is transmitted to the receiving coil 600. At this time, the receiving effect of the receiving coil 600 is optimal.

The monitoring module 111 monitors the reflected power of the transmitting coil 500 back to the monitoring circuit in real time.

The first judgment module 112 sets the first preset condition to judge whether the power value of the transmitting coil 500 satisfies the condition; the first preset condition is that there is and only one reflected power value is within the first power value preset interval; through experiments Determine the interval of the reflected power value of the transmitting coil 500 when the receiving coil 600 is at different positions from the transmitting coil 500 ; use the determined power value interval as the first power value preset interval.

After the system is started, when multiple transmitting coils 500 transmit power, multiple power values will be returned to the monitoring circuit. When one and only one of the returned power values is within the preset range of the first power value, the transmitting coil 500 will be turned on. , the other transmitting coils 500 that are not within the preset range of the first power value are turned off; otherwise, it returns to the monitoring module 111 to continue monitoring until the first preset condition is met.

Since the receiving device is not always in a constant position, considering the degree of freedom, after the first preset condition is met, the second judging module 114 then judges whether the second preset condition is met, and the second preset condition is currently enabled The number of times that the reflected power value of the transmitting coil 500 deviates from the preset interval of the second power value within the preset time is less than N; at this time, the reflected power of the single opened transmitting coil 500 is monitored, and when the reflected power value Z is within a certain If within the time T, the position of the receiving coil 600 is changed more than N times, it is determined that the position of the receiving coil 600 has changed. The reflected power value Z is the power value returned when a single transmitting coil 500 is turned on after the other transmitting coils 500 are turned off. The number of power value preset intervals.

After the wireless charging system automatically adjusts and turns on the transmitting coil 500, if the number of times Z is separated from C to D within the preset time T is less than N times, the reflected power value Z is within a reasonable value range of C to D within a certain period of time, and a single transmitting coil 500 remains on, otherwise the second preset condition is not satisfied, the system restarts all transmitting coils 500 at the transmitting end, and returns to the initial monitoring state.

The beneficial effects of the wireless charging system and method based on the power reflection selection transmitting coil 500 of the present invention at least include:

1. The wireless charging system for selecting the transmitting coil based on power reflection in the embodiment of the present invention includes: a power supply 100 for providing a stable voltage for the system; a signal generator 900 for outputting an excitation signal to the power amplifier 300 after power-on; The power amplifier 300 is used to amplify the excitation signal output by the signal generator 900 and transmit it to the transmitting coil 500 to improve the power conversion rate and transmission distance; the transmitting coil 500 is used to transmit power to the receiving coil when the excitation signal is received 600; the receiving coil 600 is used to receive the power transmitted by the transmitting coil 500 to supply power to the device; the monitoring circuit 400 is used to monitor the reflected power reflected by the transmitting coil in real time, and convert part of the reflected power into a DC voltage signal readable by the microcontroller 110 , and transmit the DC voltage signal to the single-chip microcomputer 110; the single-chip microcomputer 110 is used to judge the transmitting coil 500 closest to the receiving coil 600 after receiving the DC voltage signal, and open the transmitting coil 500 closest to the receiving coil 600 according to the judgment result, The other transmit coils 500 are turned off. The present invention judges which transmitting coil 500 is apart from the receiving coil 600 by measuring the value of the reflected power of each transmitting coil 500 when all transmitting coils 500 are energized and turned on, and turns on the transmitting coil 500 closest to the receiving coil 600, The other transmitting coils 500 are turned off, and all the transmitting power is distributed to the enabled transmitting coil 500, so as to improve the receiving efficiency of the total transmitting power. The invention can provide the user with the best charging state through the monitoring of reflected power data.

2. The wireless charging system of the present invention can independently determine the receiving position of the receiving coil 600 through the power value reflected by the transmitting coil 500, thereby switching between the states of multiple transmitting coils 500 and a single transmitting coil 500, and improving the receiving efficiency of the system.

3. The three-dimensional combination of the transmitting coil 500 at the transmitting end of the present invention increases the receiving area of the system in multiple directions. Compared with the single transmitting coil 500, the three-dimensional multi-coil array arrangement adopted in this patent increases the receiving coil 600 receiving area. The degree of freedom of position has a receiving area in the three-dimensional space of the entire device, which improves the functionality and practicability of the wireless charging system of this patent compared with the traditional magnetic coupling wireless charging.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A wireless charging system based on power reflection to select a transmitting coil, comprising: a power supply, a power amplifier, a signal generator, a monitoring circuit, a transmitting coil, a single-chip microcomputer and a receiving coil; The power supply is used to provide a stable voltage for the system; The signal generator is used to output an excitation signal to the power amplifier after being powered on; The power amplifier is used to amplify the excitation signal output by the signal generator and transmit it to the transmitting coil to improve the power conversion rate and transmission distance; The transmitting coil is configured to transmit power to the receiving coil when the excitation signal is received; The receiving coil is used to receive the power transmitted by the transmitting coil and supply power to the device; The monitoring circuit is used to monitor the reflected power returned by the transmitting coil in real time, convert part of the reflected power into a DC voltage signal readable by the single-chip microcomputer, and transmit the DC voltage signal to the single-chip microcomputer; The single-chip microcomputer is used to judge the transmitting coil closest to the receiving coil after receiving the DC voltage signal, and keep turning on the transmitting coil closest to the receiving coil and turn off other coils according to the judgment result. the transmitting coil. 2. The wireless charging system based on power reflection to select the transmitting coil according to claim 1, wherein the single-chip microcomputer comprises: A monitoring module, configured to monitor in real time the reflected power of the transmitting coil returning to the monitoring circuit; The first judging module is used to judge whether the first preset condition is currently met by monitoring the reflected power obtained, and the first preset condition is that there is one and only one value of the reflected power within the first power value preset within the set interval; A transmitting coil closing module, configured to keep on the transmitting coils satisfying the first preset condition and turn off other transmitting coils not satisfying the first preset condition if the first preset condition is met, and always All transmitting power is delivered to the activated transmitting coil, and if the first preset condition is not satisfied, the real-time monitoring state is maintained; The second judging module is used to judge whether the reflected power value of the currently turned-on transmitting coil satisfies a second preset condition, and the second preset condition is that the reflected power value of the currently turned-on transmitting coil is within a preset time The number of times of leaving the preset interval of the second power value within the period is less than N; The initialization module is configured to keep the currently turned on transmitting coil if the second preset condition is satisfied, and return to the initial real-time monitoring state if the second preset condition is not satisfied. 3. The wireless charging system for selecting a transmitting coil based on power reflection according to claim 2, wherein the monitoring circuit includes a directional coupler and a logarithmic detector; the directional coupler is used to receive the signal returned by the transmitting coil For reflected power, the logarithmic detector is used to convert part of the power received by the directional coupler into a DC voltage signal readable by the single-chip microcomputer and transmit the signal to the single-chip microcomputer. 4. The wireless charging system for selecting a transmitting coil based on power reflection according to claim 3, wherein the system further comprises: A switch circuit, the switch circuit includes a plurality of relays that control the corresponding transmitting coils; the switch circuit is connected to the single-chip microcomputer, and the single-chip microcomputer controls the on-off of the relay, thereby controlling the power amplifier and the On and off of the transmitting coil. 5 . The wireless charging system based on power reflection selective transmitting coils according to claim 4 , wherein the signal output by the signal generator is a 6.78 MHz excitation signal. 6. The wireless charging system for selecting a transmitting coil based on power reflection according to claim 5, wherein a resonant coil is arranged on the transmitting coil, and the natural frequency of the resonant coil is controlled between 6.78MHz±15kHz, so The transmitting coil generates resonance and transmits power after inputting the excitation signal. 7. The wireless charging system based on power reflection selection of transmitting coils according to claim 6, wherein the number of the transmitting coils is six, and the six transmitting coils form a cuboid shape, the top surface of the cuboid and The bottom surface is a square resonant coil, the four sides of the cuboid are rectangular resonant coils, and the transmitting coils have the same size and specification. 8. The wireless charging system based on power reflection and selective transmitting coil according to claim 7, characterized in that the system further comprises a voltage stabilizing rectifier, and the receiving coil rectifies the received power through the stabilizing rectifier to output a stable DC voltage. 9. A wireless charging method for selecting a transmitting coil based on power reflection, comprising the following steps: The system receives a starting instruction, and the starting instruction includes at least a power-on signal; When receiving the energization signal, the signal generator generates an excitation signal and outputs it to be amplified by the power amplifier; When the excitation signal is received, the power amplifier amplifies the excitation signal output by the signal generator and transmits it to the transmitting coil to improve the power conversion rate and transmission distance; When the transmitting coil receives the excitation signal, the transmitting coil transmits power to the receiving coil; The receiving coil receives the power transmitted by the transmitting coil and supplies power to the device; Real-time monitoring of the reflected power returned by the transmitting coil, converting part of the reflected power into a DC voltage signal readable by the single-chip microcomputer, and transmitting the DC voltage signal to the single-chip microcomputer; After the single-chip microcomputer receives the DC voltage signal, it judges the transmitting coil closest to the receiving coil, and according to the judgment result, keeps turning on the transmitting coil closest to the receiving coil, and turns off the other transmitting coils . 10. The wireless charging method for selecting a transmitting coil based on power reflection according to claim 9, wherein the single-chip microcomputer judges the transmitting coil closest to the receiving coil after receiving the DC voltage signal, and according to the judgment As a result, keeping on said transmitting coil closest to said receiving coil and switching off the other said transmitting coils comprises the following steps: monitoring the reflected power returned by the transmitting coil in real time; Judging whether a first preset condition is currently satisfied by monitoring the reflected power, the first preset condition is that there is one and only one value of the reflected power within the first power value preset range; If the first preset condition is met, the transmitting coils that meet the first preset condition are kept turned on, and the other transmitting coils that do not meet the first preset condition are turned off, and the total transmitting power is delivered to the opened coils. If the transmitting coil does not meet the first preset condition, it will maintain the continuous real-time monitoring state; judging whether the reflected power value of the currently turned-on transmitting coil satisfies a second preset condition, the second preset condition being that the reflected power value of the currently turned-on transmitting coil deviates from the second power value preset within a preset time Let the number of times in the interval be less than N; If the second preset condition is satisfied, the transmitting coil that is currently turned on is kept, and if the second preset condition is not met, then the initial real-time monitoring state is entered.

Images