Wireless charging device, system and method

Abstract

The invention discloses a wireless charging device, system and method. According to the wireless charging device, a filtering module is connected with a first input end and a second input end, the filtering module comprises at least one filtering capacitor, and the filtering module is configured to filter accessed alternating current; the resonance module is connected with the filter capacitor in parallel, the resonance module comprises a resonance capacitor and a resonance inductor which are connected in series, and the resonance module is configured to generate oscillation waves based on the filtered alternating current; the first end of the switch module is connected between the resonant capacitor and the filter capacitor, and the second end of the switch module is connected with the resonant inductor; the switch module is configured to maintain a conductive state when detecting a metal object. By adopting the scheme, the anti-interference capability during metal object detection is enhanced, and the accuracy of metal object detection is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging, and in particular, to a wireless charging device, system and method. Background Art

[0002] With the further development of technology, wireless power transmission emerges as an efficient and convenient mechanism for powering or charging battery-based mobile devices such as mobile phones, tablet PCs, digital cameras, MP3 players, etc. A wireless power transmission system generally includes a primary transmitter and a secondary receiver. The primary transmitter is coupled to the secondary receiver through magnetic coupling.

[0003] Before wireless power transmission, the wireless power transmission system will detect whether there is a metal object that has an adverse effect on power transmission within the power transmission range to avoid the adverse effect of foreign objects on power transmission.

[0004] However, the prior art directly uses a wireless charging circuit to detect metal objects. There are many components in the circuit and the circuit structure is complex, which also results in poor anti-interference ability during metal object detection and low accuracy of metal object detection. Summary of the Invention

[0005] The present invention provides a wireless charging device, system and method to enhance the anti-interference ability during metal object detection and improve the accuracy of metal object detection.

[0006] According to an aspect of the present invention, there is provided a wireless charging device, which includes:

[0007] A first input terminal and a second input terminal, the first input terminal and the second input terminal are connected to an alternating current;

[0008] A filtering module, the filtering module is connected to the first input terminal and the second input terminal, the filtering module includes at least one filtering capacitor, and the filtering module is configured to filter the input alternating current;

[0009] A resonance module, the resonance module is connected in parallel with the filtering capacitor, the resonance module includes a resonance capacitor and a resonance inductor connected in series, and the resonance module is configured to generate an oscillation wave based on the filtered alternating current;

[0010] A switching module, a first end of the switching module is connected between the resonance capacitor and the filtering capacitor, and a second end of the switching module is connected to the resonance inductor; the switching module is configured to maintain a conducting state when detecting a metal object.

[0011] Optionally, the first end of the switching module is connected to the second end of the filtering capacitor, the second end of the switching module is connected to the second end of the resonant inductor, the first end of the resonant inductor is connected to the first end of the filtering capacitor, the second end of the resonant inductor is connected to the first end of the resonant capacitor, and the second end of the resonant capacitor is connected to the second end of the filtering capacitor.

[0012] Optionally, the first end of the switching module is connected to the second end of the filtering capacitor, the second end of the switching module is connected to the first end of the resonant inductor, the first end of the resonant inductor is connected to the first end of the filtering capacitor, the second end of the resonant inductor is connected to the first end of the resonant capacitor, and the second end of the resonant capacitor is connected to the second end of the filtering capacitor.

[0013] Optionally, the filtering capacitors in the filtering module are connected in parallel with each other.

[0014] Optionally, the filtering module further includes at least one filtering inductor, and the filtering inductor is connected in series with the filtering capacitor.

[0015] Optionally, the filtering module includes: one filtering capacitor and two filtering inductors;

[0016] The first end of the first filtering inductor is connected to the first input terminal, the first end of the second filtering inductor is connected to the second input terminal, the second end of the first filtering inductor is connected to the first end of the filtering capacitor, and the second end of the second filtering inductor is connected to the second end of the filtering capacitor.

[0017] Optionally, the wireless charging device further includes: an inverter module and a control module;

[0018] The DC input terminal of the inverter module is connected to a DC power supply, the first output terminal of the inverter module is connected to the first input terminal, the second output terminal of the inverter module is connected to the second input terminal, the control terminal of the inverter module is connected to the control module, and the control module is further connected to the control terminal of the switching module and the resonant module respectively;

[0019] The inverter module is configured to convert the direct current output by the DC power supply into alternating current; the control module is configured to control the switching module to close during metal object detection.

[0020] Optionally, the inverter module includes: a first switch, a second switch, a third switch, and a fourth switch;

[0021] The first end of the first switch is connected to the positive pole of the DC power supply, the second end of the first switch is connected to the first end of the second switch, the second end of the second switch is connected to the negative pole of the DC power supply, the first end of the second switch is also connected to the first input terminal, the first end of the third switch is connected to the positive pole of the DC power supply, the second end of the third switch is connected to the first end of the fourth switch, the second end of the fourth switch is connected to the negative pole of the DC power supply, the first end of the fourth switch is also connected to the second input terminal, the control terminals of the first switch, the second switch, the third switch and the fourth switch are all connected to the control module, and the second ends of the second switch and the fourth switch are also grounded.

[0022] Optionally, the first switch, the second switch, the third switch and the fourth switch are all power switch tubes.

[0023] Optionally, the switch module includes: a fifth switch;

[0024] The first end of the fifth switch serves as the first end of the switch module, the second end of the fifth switch serves as the second end of the switch module, and the control end of the fifth switch serves as the control end of the switch module.

[0025] Optionally, the control module includes: a processor and a buck circuit;

[0026] The processor is respectively connected to the control end of the switch module and the control end of the inverter module, the input end of the buck circuit is connected to the output end of the resonance module, and the output end of the buck circuit is connected to the processor;

[0027] The buck circuit is configured to reduce the waveform voltage of the oscillating wave; the processor is configured to control the switch module to close during metal object detection.

[0028] According to another aspect of the present invention, there is also provided a wireless charging system, which includes at least one wireless charging device according to any one of the above embodiments.

[0029] According to still another aspect of the present invention, there is also provided a wireless charging method, which is executed by the wireless charging device according to any one of the above embodiments; the wireless charging method includes:

[0030] Providing alternating current;

[0031] Maintaining the switch module conducting during metal object detection.

[0032] Optionally, after maintaining the switch module conducting during metal object detection, it further includes:

[0033] Keep the switch module off during wireless charging.

[0034] The filtering module of the embodiment of the present invention filters the alternating current connected between the first input end and the second input end. The switch module maintains a conducting state during metal object detection to reduce the number of devices participating in the generation of the oscillation wave during metal object detection; the switch module maintains an off state during wireless charging, and at this time, electric energy oscillates in the resonant module and the filtering capacitor, so as to generate an oscillation wave that meets the charging frequency requirement. The switch module of the embodiment of the present invention maintains a conducting state during metal object detection to reduce the number of devices participating in the generation of the oscillation wave during metal object detection, simplifies the structure of the resonant cavity for generating the oscillation wave during metal object detection, thereby facilitating enhancing the anti-interference ability during metal object detection and improving the accuracy of metal object detection.

[0035] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understandable through the following description. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 It is a schematic diagram of a wireless charging device provided by an embodiment of the present invention;

[0038] Figure 2 It is a schematic diagram of another wireless charging device provided by an embodiment of the present invention;

[0039] Figure 3 It is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0041] Figure 5 It is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0042] Figure 6 It is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0043] Figure 7 It is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0044] Figure 8 It is a schematic diagram of another wireless charging device provided by an embodiment of the present invention.

[0045] Figure 9 It is a schematic diagram of a wireless charging system provided by an embodiment of the present invention;

[0046] Figure 10 It is a flowchart of a wireless charging method provided by an embodiment of the present invention;

[0047] Figure 11 It is a flowchart of another wireless charging method provided by an embodiment of the present invention. Detailed implementation manners

[0048] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0050] An embodiment of the present invention provides a wireless charging device. The wireless charging device is applicable to wireless charging of electronic devices. The control module in this embodiment enables the switch module when detecting a metal object, so as to reduce the number of devices participating in the generation of oscillation waves during metal object detection, simplify the structure of the resonant cavity for generating oscillation waves during metal object detection, thereby facilitating enhancing the anti-interference ability of the wireless charging device during metal object detection and improving the accuracy of metal object detection. Figure 1 It is a schematic diagram of a wireless charging device provided by an embodiment of the present invention. Figure 2 It is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. Refer to Figure 1 and Figure 2, the wireless charging device includes: a first input terminal A, a second input terminal B, a filtering module 110, a resonance module 120, and a switching module 130.

[0051] The first input terminal A and the second input terminal B are connected to alternating current; the filtering module 110 is connected to the first input terminal A and the second input terminal B. The filtering module 110 includes at least one filtering capacitor C1. The filtering module 110 is configured to filter the input alternating current; the resonance module 120 is connected in parallel with the filtering capacitor C1. The resonance module 120 includes a resonance capacitor C2 and a resonance inductor L2 connected in series. Wherein, the first end of the resonance inductor L2 is connected to one end of the filtering capacitor C1, the second end of the resonance inductor L2 is connected to the first end of the resonance capacitor C2, the second end of the resonance capacitor C2 is connected to the other end of the filtering capacitor C1. The resonance module 120 is configured to generate an oscillation wave based on the filtered alternating current; the first end of the switching module 130 is connected between the resonance capacitor C2 and the filtering capacitor C1, and the second end of the switching module 130 is connected to the resonance inductor L2; the switching module 130 is configured to maintain a conducting state when detecting a metal object.

[0052] Wherein, the first end of the resonance inductor L2 is connected to the first end of the filtering capacitor C1, the second end of the resonance inductor L2 is connected to the first end of the resonance capacitor C2, and the second end of the resonance capacitor C2 is connected to the second end of the filtering capacitor C1. In application, according to different actual requirements, the connection mode of the switching module 130 in the wireless charging device is also different. The following respectively describes different connection modes of the switching module 130. Combining Figure 1 , the first end of the switching module 130 is connected to the second end of the filtering capacitor C2, and the second end of the switching module 130 is connected to the first end of the resonance inductor L2; combining Figure 2 , the first end of the switching module 130 is connected to the second end of the filtering capacitor C2, and the second end of the switching module 130 is connected to the second end of the resonance inductor L2.

[0053] Specifically, the filtering module 110 filters the alternating current connected between the first input terminal A and the second input terminal B, and outputs the filtered alternating current to the resonant module 120. Optionally, the filtering module 110 may also be provided with a filtering inductor L1, and the filtering inductor L1 is connected in series with a filtering capacitor C1. In practical applications, both the filtering inductor L1 and the filtering capacitor C1 may be multiple. When there are multiple filtering capacitors C1, the filtering capacitors C1 are connected in parallel with each other. When the wireless charging device wirelessly charges an electronic device, the switching module 130 is turned off until the wireless charging ends; when the wireless charging device detects whether there is a metal object within its charging range, the switching module 130 is turned on until the metal object detection ends. Among them, the timing for the wireless charging device to detect whether there is a metal object within its charging range may be, for example, before the wireless charging device wirelessly charges the electronic device.

[0054] When detecting a metal object, an alternating current is input between the first input terminal A and the second input terminal B for a preset time to provide electrical energy for the wireless charging device. After reaching the preset time, the input of the alternating current between the first input terminal A and the second input terminal B is interrupted. Exemplarily, the alternating current input between the first input terminal A and the second input terminal B may be provided by a switching power supply. In practical applications, the input of the alternating current between the first input terminal A and the second input terminal B can be controlled by controlling the conduction or turn-off of the switching power supply. Among them, the preset time is the power supply time of the alternating current during the metal object detection set in advance, and can be set according to actual needs in practical applications. This embodiment does not limit this.

[0055] It should be noted that the switching module 130 can be set according to actual needs to shield different devices, so as to form different resonant cavities during metal object detection. The following describes different structures of resonant cavities.

[0056] Continue to refer to Figure 1 , the switching module 130 may be connected in parallel with the filtering capacitor C1. Figure 3 is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. Combining Figure 1 and Figure 3 , after reaching the preset time, the wireless charging device performs metal object detection, the switching module 130 is turned on, and the switching module 130 shorts the filtering capacitor C1, so that the switching module 130, the resonant capacitor C2 in the resonant module 120, and the resonant inductor L2 in the resonant module 120 form a closed loop, jointly constituting the resonant cavity 200. Therefore, when the switching module 130 is turned on, the filtering capacitor C1 is prevented from participating in resonance, reducing the resonant devices. At this time, the devices participating in the generation of the oscillation wave (the devices in the resonant cavity 200) are fewer, and the mutual interference between the devices during the generation of the oscillation wave is reduced, and the anti-interference ability of the wireless charging device during metal object detection is enhanced.

[0057] Continuing to refer to Figure 2 , the switching module 130 can also be connected in parallel with the resonant capacitor C2. Figure 4 is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. Combining Figure 2 and Figure 4 , after reaching the preset time, the wireless charging device performs metal object detection, the switching module 130 is turned on, and the switching module 130 shorts the resonant capacitor C2, so that the switching module 130, the filter capacitor C1 in the filter module 110, and the resonant inductor L2 in the resonant module 120 form a closed loop, jointly constituting the resonant cavity 200. Therefore, when the switching module 130 is turned on, the resonant capacitor C2 does not participate in resonance, reducing the resonant devices. At this time, the devices participating in the generation of the oscillation wave (the devices in the resonant cavity 200) are fewer, and the mutual interference between the devices during the generation of the oscillation wave is reduced, enhancing the anti-interference ability of the wireless charging device during metal object detection.

[0058] When the switching module 130 is closed, the electric energy stored in the wireless charging device generates oscillations in the resonant cavity 200, thereby generating an oscillation wave. At this time, the quality factor of the resonant cavity 200 can be calculated through the frequency of the oscillation wave generated by the resonant cavity 200.

[0059] Since when a metal object enters the charging range of the wireless charging device, the resonant point generated by the resonant cavity 200 changes, and when the resonant point of the resonant cavity 200 changes, the frequency of the oscillation wave generated by the resonant cavity 200 also changes accordingly. When the resonant points of the resonant cavity 200 are different, the quality factors of the resonant cavity 200 are different. Therefore, it is possible to judge whether there is a metal object in the charging range of the wireless charging device according to the quality factor of the resonant cavity 200. When the quality factor of the resonant cavity 200 is outside the preset range, it indicates that there is a metal object in the charging range of the wireless charging device at this time; when the quality factor of the resonant cavity 200 is within the preset range, it indicates that there is no metal object in the charging range of the wireless charging device at this time. It should be noted that the preset range is the frequency range of the oscillation wave generated by the resonant cavity 200 when there is no metal object in the charging range of the wireless charging device set in advance. The preset range depends on the electrical characteristics of each device in the resonator 200 and can be set according to actual needs in actual applications. This embodiment does not limit this.

[0060] Among them, when there is a metal object in the charging range of the wireless charging device, the quality factor of the resonant cavity 200 is continuously detected until there is no metal object in the charging range of the wireless charging device. When there is no metal object in the charging range of the wireless charging device, the wireless charging device normally performs wireless charging. At this time, alternating current is continuously input between the first input terminal A and the second input terminal B, and the switching module 130 is turned off.

[0061] The filtering module 110 in the embodiment of the present invention filters the alternating current connected between the first input terminal A and the second input terminal B. When detecting a metal object, the switch module 130 maintains a conducting state to reduce the number of devices participating in the generation of the oscillation wave during metal object detection; when wirelessly charging, the switch module 130 maintains a cut-off state. At this time, electric energy oscillates in the resonance module 120 and the filtering capacitor C1, thereby generating an oscillation wave that meets the charging frequency requirement. The switch module 130 in the embodiment of the present invention maintains a conducting state when detecting a metal object, so as to reduce the number of devices participating in the generation of the oscillation wave during metal object detection, simplify the structure of the resonance cavity 200 for generating the oscillation wave during metal object detection, thereby facilitating enhancing the anti-interference ability during metal object detection and improving the accuracy of metal object detection.

[0062] Figure 5 is a schematic diagram of another wireless charging device provided by the embodiment of the present invention. When the switch module 130 can be connected in parallel with the filtering capacitor C1, on the basis of the above embodiments, optionally, referring to Figure 5 , the wireless charging device may further be provided with a frequency conversion capacitor C3 and a frequency conversion switch S6 connected in series. The branch where the frequency conversion capacitor C3 and the frequency conversion switch S6 are located is connected in parallel with the resonance capacitor C2. The frequency conversion switch S6 is configured to maintain a conducting state when detecting a metal object. Among them, when the wireless charging device is detecting a metal object, the frequency conversion switch S6 is turned on, and when the wireless charging device is wirelessly charging, the frequency conversion switch S6 is turned off. When the frequency conversion capacitor C3 is connected in parallel with the resonance capacitor C2, the resonance point of the resonance cavity 200 during resonance changes, so that the frequency of the oscillation wave generated by the resonance cavity 200 during metal object detection is different from the frequency of the oscillation wave generated by the resonance cavity 200 during wireless charging, thereby avoiding the interference of the adjacent wireless charging device during metal object detection.

[0063] On the basis of the above embodiments, optionally, in combination with Figure 1 and Figure 2 , the filtering module 110 includes: a filtering capacitor C1 and two filtering inductors L1.

[0064] The first end of the first filtering inductor L1 is connected to the first input terminal A, the first end of the second filtering inductor L1 is connected to the second input terminal B, the second end of the first filtering inductor L1 is connected to the first end of the filtering capacitor C1, and the second end of the second filtering inductor L1 is connected to the second end of the filtering capacitor C1.

[0065] Figure 6 is a schematic diagram of another wireless charging device provided by the embodiment of the present invention. On the basis of the above embodiments, optionally, referring to Figure 6 , the wireless charging device further includes: an inverter module 150 and a control module 140.

[0066] The DC input terminal of the inverter module 150 is connected to the DC power supply 10, the first output terminal of the inverter module 150 is connected to the first input terminal A, the second output terminal of the inverter module 150 is connected to the second input terminal B, the control terminal of the inverter module 150 is connected to the control module 140, and the control module 140 is also respectively connected to the control terminal of the switch module 130 and the resonance module 120; the inverter module 150 is configured to convert the direct current output by the DC power supply 10 into alternating current; the control module 140 is configured to control the switch module 130 to close during metal object detection.

[0067] Exemplarily, the DC power supply 10 can be any suitable DC energy storage device or power generation device, such as a renewable rechargeable battery, a fuel cell, and a photovoltaic panel.

[0068] Specifically, when detecting whether there is a metal object within the charging range of the wireless charging device, the control module 140 can control the alternating current indirectly connected to the first input terminal A and the second input terminal B by driving the inverter module 150.

[0069] The control module 140 drives the inverter module 150 to operate for a preset time to convert the direct current output by the DC power supply 10 into alternating current, so as to provide electrical energy for the wireless charging device. Among them, when the control module 140 stops driving the inverter module 150, the inverter module 150 is completely turned off, and at this time, the inverter module 150 is equivalent to an open circuit.

[0070] After reaching the preset time, the wireless charging device performs metal object detection, and the control module 140 enables the switch module 130 to make the switch module 130 close. When the switch module 130 closes, the electrical energy stored in the wireless charging device generates oscillations in the resonance cavity 200, thereby generating oscillation waves. At this time, the control module 140 calculates the quality factor of the resonance cavity 200 through the frequency of the oscillation waves generated by the resonance cavity 200, and judges whether there is a metal object in the wireless charging device according to the quality factor of the resonance cavity 200. When the quality factor of the resonance cavity 200 is outside the preset range, it indicates that there is a metal object within the charging range of the wireless charging device at this time; when the quality factor of the resonance cavity 200 is within the preset range, it indicates that there is no metal object within the charging range of the wireless charging device at this time.

[0071] When there is a metal object within the charging range of the wireless charging device, the control module 140 continuously detects the quality factor of the resonance cavity 200 until there is no metal object within the charging range of the wireless charging device. When there is no metal object within the charging range of the wireless charging device, the wireless charging device normally performs wireless charging. At this time, alternating current is continuously input between the first input terminal A and the second input terminal B, and the control module 140 stops enabling the switch module 130 to make the switch module 130 turn off. At this time, the wireless charging device performs wireless charging externally.

[0072] Figure 7 It is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. On the basis of the above embodiments, optionally, referring to Figure 7 , the inverter module 150 includes: a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4.

[0073] The first end of the first switch S1 is connected to the positive pole of the DC power supply 10, the second end of the first switch S1 is connected to the first end of the second switch S2, the second end of the second switch S2 is connected to the negative pole of the DC power supply 10, the first end of the second switch S2 is also connected to the first input terminal A, the first end of the third switch S3 is connected to the positive pole of the DC power supply 10, the second end of the third switch S3 is connected to the first end of the fourth switch S4, the second end of the fourth switch S4 is connected to the negative pole of the DC power supply 10, the first end of the fourth switch S4 is also connected to the second input terminal B, the control ends of the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are all connected to the control module 140, and the second end of the second switch S2 and the second end of the fourth switch S4 are also grounded.

[0074] Wherein, when the control module 140 stops driving the inverter module 150, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are all in the off state, and at this time, the inverter module 150 is an open circuit. Exemplarily, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 can all be power switch tubes, such as metal-oxide semiconductor field effect transistors (MOSFETs, MOS), bipolar junction transistors (BJTs), or insulated gate bipolar transistors (IGBTs), etc.

[0075] On the basis of the above embodiments, optionally, continue to refer to Figure 6 , the switch module 130 can be a fifth switch S5. The first end of the fifth switch S5 is used as the first end of the switch module 130, the second end of the fifth switch S5 is used as the second end of the switch module 130, and the control end of the fifth switch S5 is used as the control end of the switch module 130. Wherein, the fifth switch S5 can be a transistor switch, a thyristor switch, a solid state relay, or an integrated electronic switch, etc. Among them, those skilled in the art can reasonably configure the first end, the second end, and the control end of the fifth switch S5 corresponding to the respective ports of the selected type of switch.

[0076] Figure 8It is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. On the basis of the above embodiments, optionally, referring to Figure 8 , the control module 140 includes: a processor 141 and a buck circuit 142.

[0077] The processor 141 is respectively connected to the control end of the switch module 130 and the control end of the inverter module 150. The input end of the buck circuit 142 is connected to the output end of the resonance module 120, and the output end of the buck circuit 142 is connected to the processor 141; the buck circuit 142 is configured to reduce the waveform voltage of the oscillation wave; the processor is configured to control the switch module 130 to close during metal object detection. In this embodiment, the output end of the resonance module 120 can be any position of the resonance cavity, such as the second end of the resonance inductor L2.

[0078] In this embodiment, the buck circuit 142 is used to reduce the waveform voltage of the oscillation wave to convert the oscillation wave into waveform data that can be collected by the analog-to-digital converter in the processor 141.

[0079] Specifically, the filtering module 110 filters the alternating current connected between the first input end A and the second input end B, and outputs the filtered alternating current to the resonance module 120. When the wireless charging device performs wireless charging on an electronic device, the processor 141 stops enabling the switch module 130; when the wireless charging device detects whether there is a metal object within its charging range, the processor 141 enables the switch module 130. Exemplarily, the processor 141 can be a processor.

[0080] After the processor 141 enables the switch module 130, the buck circuit 142 acquires the oscillation wave generated by the resonance cavity 200 and generates waveform data based on the oscillation wave. The processor 141 acquires the waveform data of the buck circuit 142 and calculates the quality factor of the resonance cavity 200 according to the waveform data. The processor 141 compares the calculated quality factor of the resonance cavity with a preset range. When the quality factor of the resonance cavity 200 is outside the preset range, it is considered that there is a metal object within the charging range of the wireless charging device; when the quality factor of the resonance cavity 200 is within the preset range, it is considered that there is no metal object within the charging range of the wireless charging device.

[0081] Wherein, when the processor 141 calculates the quality factor of the resonance cavity according to the waveform data, the processor 141 calculates the frequency of the oscillation wave from the waveform data. On the basis that the frequency of the oscillation wave is known, the processor 141 calculates the quality factor of the resonance cavity according to the following formula:

[0082]

[0083] Wherein, Q is the quality factor of the resonant cavity; f is the frequency of the oscillating wave; L is the inductance value of the equivalent inductor in the resonant cavity; R is the resistance value of the equivalent resistance of the device in the resonant cavity.

[0084] An embodiment of the present invention also provides a wireless charging system. Figure 9 is a schematic diagram of a wireless charging system provided by an embodiment of the present invention. Refer to Figure 9 , the wireless charging system 1000 includes at least one wireless charging device 100 provided by any of the above embodiments.

[0085] It should be noted that the wireless charging system 1000 provided by the embodiments of the present invention has the beneficial effects of the wireless charging device 100 provided by any of the above embodiments, which will not be elaborated here.

[0086] An embodiment of the present invention also provides a wireless charging method. Figure 10 is a flowchart of a wireless charging method provided by an embodiment of the present invention. The wireless charging method is executed by the wireless charging device provided by any of the above embodiments. Refer to Figure 10 , the wireless charging method includes:

[0087] S110. Provide alternating current.

[0088] S120. Keep the switch module conducting during metal object detection.

[0089] Specifically, in combination with Figure 1 , when the switch module is conducting, the switch module shorts the filtering module, and at this time, only the resonant module participates in resonance; or in combination with Figure 2 , when the switch module is conducting, the switch module shorts the resonant capacitor, and at this time, only the resonant inductor of the resonant module and the resonant capacitor of the filtering module participate in resonance. That is to say, when the switch module is conducting, the devices participating in the generation of the oscillating wave are reduced, thereby reducing the mutual interference between devices during the generation of the oscillating wave and enhancing the anti-interference ability of the wireless charging device during metal object detection.

[0090] Exemplarily, in combination with Figure 6 , the conduction or cutoff of the switch module can be controlled by the control module. During metal object detection, the control module continuously sends an enabling signal to the switch module to make the switch module conduct under the action of the enabling signal. It should be noted that the conduction of the switch module needs to be maintained by the enabling signal, and when the control module stops sending the enabling signal, the switch module turns off.

[0091] Figure 11 is a flowchart of another wireless charging method provided by an embodiment of the present invention. On the basis of the above embodiments, optionally, refer to Figure 11 , after keeping the switch module conducting during metal object detection, it further includes:

[0092] S130. Keep the switch module off during wireless charging.

[0093] Specifically, the control module calculates the quality factor of the oscillating wave generated by the wireless charging device.

[0094] Among them, the frequency of the oscillating wave can be calculated by the following formula:

[0095]

[0096] Among them, f is the frequency of the oscillating wave; L is the inductance value in the resonant cavity; C is the capacitance value in the resonant cavity.

[0097] On the basis that the frequency of the oscillating wave is known, the quality factor of the resonant cavity can be calculated according to the following formula:

[0098]

[0099] Among them, Q is the quality factor of the resonant cavity; f is the frequency of the oscillating wave; L is the inductance value of the equivalent inductor in the resonant cavity; R is the resistance value of the equivalent resistance of the devices in the resonant cavity.

[0100] When the quality factor is outside the preset range, it is considered that there is a metal object in the charging range of the wireless charging device; when the quality factor is within the preset range, it is considered that there is no metal object in the charging range of the wireless charging device.

[0101] When there is no metal object in the charging range of the wireless charging device, the wireless charging system can perform wireless charging normally. At this time, the switch module is stopped from being enabled to perform wireless charging for the electronic device.

[0102] During wireless charging, alternating current is continuously input between the first input terminal and the second input terminal. At this time, the switch module remains off, the filtering module filters the input alternating current, and the resonant module generates an oscillating wave based on the filtered alternating current to achieve external wireless charging.

[0103] It should be understood that various forms of the processes shown above can be used, and the steps can be reordered, added, or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. No limitation is imposed herein.

[0104] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wireless charging device, characterized in that, Comprising: A first input terminal and a second input terminal, wherein the first input terminal and the second input terminal are connected to an alternating current power supply; A filtering module, the filtering module is connected to the first input terminal and the second input terminal, the filtering module includes at least one filtering capacitor, and the filtering module is configured to filter the input alternating current; A resonance module, the resonance module is connected in parallel with the filtering capacitor, the resonance module includes a resonance capacitor and a resonance inductor connected in series, and the resonance module is configured to generate an oscillation wave based on the filtered alternating current; A switching module, a first end of the switching module is connected between the resonance capacitor and the filtering capacitor, and a second end of the switching module is connected to the resonance inductor; the switching module is configured to maintain a conducting state when detecting a metal object.

2. The wireless charging device according to claim 1, wherein The first end of the switching module is connected to the second end of the filtering capacitor, the second end of the switching module is connected to the second end of the resonance inductor, the first end of the resonance inductor is connected to the first end of the filtering capacitor, the second end of the resonance inductor is connected to the first end of the resonance capacitor, and the second end of the resonance capacitor is connected to the second end of the filtering capacitor.

3. The wireless charging device according to claim 1, wherein The first end of the switching module is connected to the second end of the filtering capacitor, the second end of the switching module is connected to the first end of the resonance inductor, the first end of the resonance inductor is connected to the first end of the filtering capacitor, the second end of the resonance inductor is connected to the first end of the resonance capacitor, and the second end of the resonance capacitor is connected to the second end of the filtering capacitor.

4. The wireless charging device according to any one of claims 1-3, characterized in that, The filtering capacitors in the filtering module are connected in parallel with each other.

5. The wireless charging device according to any one of claims 1-3, characterized in that, The filtering module further includes at least one filtering inductor, and the filtering inductor is connected in series with the filtering capacitor.

6. The wireless charging device according to claim 5, wherein The filtering module includes: one filtering capacitor and two filtering inductors; The first end of the first filtering inductor is connected to the first input terminal, the first end of the second filtering inductor is connected to the second input terminal, the second end of the first filtering inductor is connected to the first end of the filtering capacitor, and the second end of the second filtering inductor is connected to the second end of the filtering capacitor.

7. The wireless charging device according to claim 1, wherein, Further comprising: An inverter module and a control module; The DC input terminal of the inverter module is connected to a DC power supply, the first output terminal of the inverter module is connected to the first input terminal, the second output terminal of the inverter module is connected to the second input terminal, the control terminal of the inverter module is connected to the control module, and the control module is further connected to the control terminal of the switching module and the resonance module respectively; The inverter module is configured to convert the direct current output by the DC power supply into an alternating current; the control module is configured to control the switching module to close when detecting a metal object.

8. The wireless charging device according to claim 7, wherein The inverter module includes: a first switch, a second switch, a third switch, and a fourth switch; The first end of the first switch is connected to the positive pole of the DC power supply, the second end of the first switch is connected to the first end of the second switch, the second end of the second switch is connected to the negative pole of the DC power supply, the first end of the second switch is also connected to the first input terminal, the first end of the third switch is connected to the positive pole of the DC power supply, the second end of the third switch is connected to the first end of the fourth switch, the second end of the fourth switch is connected to the negative pole of the DC power supply, the first end of the fourth switch is also connected to the second input terminal, the control terminals of the first switch, the second switch, the third switch and the fourth switch are all connected to the control module, and the second ends of the second switch and the fourth switch are also grounded.

9. The wireless charging device according to claim 8, wherein The first switch, the second switch, the third switch and the fourth switch are all power switch tubes.

10. The wireless charging device according to claim 7, characterized in that, The control module includes: a processor and a buck circuit; The processor is respectively connected to the control terminals of the switch module and the inverter module, the input terminal of the buck circuit is connected to the output terminal of the resonance module, and the output terminal of the buck circuit is connected to the processor; The buck circuit is configured to reduce the waveform voltage of the oscillating wave; the processor is configured to control the switch module to close during metal object detection.

11. The wireless charging device according to claim 1, characterized in that, The switch module includes: a fifth switch; The first end of the fifth switch serves as the first end of the switch module, the second end of the fifth switch serves as the second end of the switch module, and the control end of the fifth switch serves as the control end of the switch module.

12. A wireless charging system, characterized in that, Including at least one wireless charging device according to any one of claims 1-11.

13. A wireless charging method, characterized in that, Performed by the wireless charging device according to any one of claims 1-11; the wireless charging method includes: Providing alternating current; Maintaining the switch module in a conducting state during metal object detection.

14. The wireless charging device according to claim 13, wherein After maintaining the switch module in a conducting state during metal object detection, it further includes: Maintaining the switch module in an off state during wireless charging.

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