Wireless charging device, system and method

Abstract

The invention discloses a wireless charging device, system and method. The wireless charging device comprises a first input end and a second input end which are connected with alternating current; the filtering module is connected with the first input end and the second input end, the filtering module comprises a filtering capacitor, and the filtering module is configured to filter accessed alternating current; the resonance module comprises a resonance inductor and a resonance capacitor which are connected in series, a branch where the resonance inductor and the resonance capacitor are located is connected with the filter capacitor in parallel, and the resonance module is configured to generate oscillatory waves based on the filtered alternating current; the frequency selection module comprises an inductive component and a switch component which are connected in parallel, the inductive component is connected in series into a branch where the resonant inductor and the resonant capacitor are located, and the frequency selection module is configured to maintain a turn-off state when detecting the metal object. According to the wireless charging device provided by the embodiment of the invention, interference of an adjacent wireless charging device can be avoided in a metal object detection process, 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 are metal objects that have an adverse effect on power transmission within the power transmission range to avoid the adverse effects of foreign objects on power transmission.

[0004] However, when two wireless chargers are close to each other, they will interfere with each other, resulting in poor accuracy of metal object detection. Summary of the Invention

[0005] The present invention provides a wireless charging device, system and method to solve the problem of avoiding interference from adjacent wireless charging devices during metal object detection and improving the accuracy of metal object detection.

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

[0007] A first input terminal and a second input terminal, and 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 a filtering capacitor, and the filtering module is configured to filter the input alternating current;

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

[0010] A frequency selection module, the frequency selection module includes an inductive component and a switching component connected in parallel, the inductive component is connected in series to the branch where the resonance inductor and the resonance capacitor are located, and the frequency selection module is configured to maintain an off state when detecting a metal object.

[0011] Optionally, the inductive component is connected between the resonance inductor and the filtering capacitor.

[0012] Optionally, the inductive component is connected between the resonant capacitor and the filtering capacitor.

[0013] Optionally, the inductive component is connected between the resonant inductor and the resonant capacitor.

[0014] Optionally, the inductive component includes: at least one frequency-selective inductor;

[0015] The frequency-selective inductors are connected in series, and the branches where the frequency-selective inductors are located are connected in parallel with the switching component, or each frequency-selective inductor is respectively connected in parallel with a switching component.

[0016] Optionally, the switching component includes: one of a transistor switch, a thyristor switch, a solid-state relay, or an integrated electronic switch.

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

[0018] The control module is respectively connected to the resonant module and the switching component; the control module is configured to control the switching component to turn off during metal object detection.

[0019] Optionally, the control module includes: a processor and a buck circuit;

[0020] The processor is connected to the switching component of the frequency-selective module, the input end of the buck circuit is connected to the resonant module, and the output end of the buck circuit is connected to the processor;

[0021] The buck circuit is configured to reduce the waveform voltage of the oscillation wave generated by the resonant module; the processor is configured to control the switching component to turn off during metal object detection.

[0022] Optionally, the wireless charging device further includes: an inverter module;

[0023] The DC input end of the inverter module is connected to a DC power supply, the first output end of the inverter module is connected to the first input end, the second output end of the inverter module is connected to the second input end, and the control end of the inverter module is connected to the control module;

[0024] The inverter module is configured to convert the direct current output by the DC power supply into alternating current.

[0025] Optionally, the inverter module includes: a first switch, a second switch, a third switch, and a fourth switch;

[0026] 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.

[0027] According to another aspect of the present invention, there is also provided a wireless charging system, which includes at least one wireless charging device as described in any one of the above embodiments.

[0028] 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 as described in any one of the above embodiments. The wireless charging device includes a frequency selection module, and the frequency selection module includes a switch component. The wireless charging method includes:

[0029] Providing alternating current;

[0030] Maintaining the switch component off during metal object detection.

[0031] Optionally, after maintaining the switch component off during metal object detection, it further includes:

[0032] Maintaining the switch component on during wireless charging.

[0033] The filtering module of the embodiment of the present invention filters the alternating current connected between the first input terminal and the second input terminal. During metal object detection, the switch component of the frequency selection module is turned off, so that the inductive component of the frequency selection module provides an additional inductor for the resonant module, thereby changing the frequency of the oscillation wave, so that the frequency of the oscillation wave during metal object detection is different from the frequency of the oscillation wave during wireless charging. In the embodiment of the present invention, when detecting a metal object, the switch component of the frequency selection module is turned off, so that the inductive component of the frequency selection module changes the frequency of the oscillation wave generated by the wireless charging device, so that the frequency of the oscillation wave during metal object detection is different from the frequency of the oscillation wave during wireless charging, which is beneficial to avoiding the interference of the adjacent wireless charging device during the metal object detection process and improving the accuracy of metal object detection.

[0034] It should be understood that the content described in this section 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 readily understood from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0036] Figure 1 is a schematic diagram of a wireless charging device provided by an embodiment of the present invention;

[0037] Figure 2 is a schematic diagram of another wireless charging device provided by an embodiment of the present invention;

[0038] Figure 3 is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0039] Figure 4 is an equivalent diagram of a resonant cavity during metal object detection provided by an embodiment of the present invention;

[0040] Figure 5 is an equivalent diagram of a resonant cavity during wireless charging provided by an embodiment of the present invention;

[0041] Figure 6 is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0042] Figure 7 is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0043] Figure 8 is a schematic diagram of yet another wireless charging device provided by an embodiment of the present invention;

[0044] Figure 9 is a schematic diagram of a wireless charging system provided by an embodiment of the present invention;

[0045] Figure 10 is a flowchart of a wireless charging method provided by an embodiment of the present invention;

[0046] Figure 11 is a flowchart of another wireless charging method provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0048] 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 the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] An embodiment of the present invention provides a wireless charging device. The wireless charging device is suitable for wireless charging of electronic devices. The control module of this embodiment enables the frequency selection module when detecting a metal object, so that the frequency selection module changes the frequency of the oscillation wave generated by the wireless charging device, so that the frequency of the oscillation wave during metal object detection is different from the frequency of the oscillation wave during wireless charging, which is beneficial to avoid interference from adjacent wireless charging devices during metal object detection and improve the accuracy of metal object detection. Figure 1 is a schematic diagram of a wireless charging device provided by an embodiment of the present invention. Figure 2 is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. Figure 3 is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. Figure 1 , Figure 2 and Figure 3 The wireless charging device includes: a filtering module 110 , a resonance module 120 and a frequency selection module 130 .

[0050] The first input terminal A and the second input terminal B are connected to an 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 a filtering capacitor C1, and the filtering module 110 is configured to filter the input alternating current; the resonance module 120 includes a resonance inductor L2 and a resonance capacitor C2 connected in series. The branch where the resonance inductor L2 and the resonance capacitor C2 are located is connected in parallel with the filtering capacitor C1, and the resonance module 120 is configured to generate an oscillation wave based on the filtered alternating current; the frequency selection module 130 includes an inductive component 131 and a switch component 132 connected in parallel. The inductive component 131 is connected in series to the branch where the resonance inductor L2 and the resonance capacitor C2 are located. The frequency selection module 130 is configured to maintain an off state when detecting a metal object.

[0051] Exemplarily, in combination with Figure 1 , the inductive component 131 can be connected between the resonance inductor L2 and the filtering capacitor C1; in combination with Figure 2 , the inductive component 131 can also be connected between the resonance capacitor C2 and the filtering capacitor C1; in combination with Figure 3 , the inductive component 131 can also be connected between the resonance inductor L2 and the resonance capacitor C2. Among them, the inductive component 131 can be composed of at least one frequency selection inductor L3. When there are at least two frequency selection inductors L3 in the inductive component 131, the frequency selection inductors L3 can be connected in series with each other and then connected in parallel with the switch component 132, or each frequency selection inductor L3 can be connected in parallel with a switch component 132 respectively; the switch component 132 can be a transistor switch, a thyristor switch, a solid-state relay or an integrated electronic switch, etc. Optionally, continuing to refer to Figure 1 , the filtering module 110 can also be provided with at least one filtering inductor L1, and the filtering inductor L1 is connected in series with the filtering capacitor C1.

[0052] 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 resonance module 120. When the wireless charging device wirelessly charges the electronic device, the switch component 132 of the frequency selection module 130 is closed; when the wireless charging device detects whether there is a metal object within its charging range, the switch component 132 of the frequency selection module 130 is turned off. Among them, the timing for the wireless charging device to detect whether there is a metal object within its charging range can be, for example, before the wireless charging device wirelessly charges the electronic device. Figure 4 is an equivalent diagram of a resonant cavity during metal object detection provided by an embodiment of the present invention. When the switch component 132 of the frequency selection module 130 is turned off, the inductive component 131 in the frequency selection module 130 provides an additional inductor for the resonance module 120 to change the frequency of the oscillation wave. Refer to Figure 3, At this time, the filter capacitor C1 in the filter module 110, the resonance module 120, and the inductive component 131 of the frequency selection module 130 together form a resonance cavity 200.

[0053] When electric energy enters the resonance cavity 200, the electric energy oscillates within the resonance cavity 200, thereby generating an oscillating wave. At this time, the quality factor of the resonance cavity 200 can be calculated based on the frequency of the oscillating wave generated by the resonance cavity 200.

[0054] Among them, the inductive component 131 exhibits inductive properties. When the inductive component 131, the filter capacitor C1 in the filter module 110, and the resonance module 120 form the resonance cavity 200, the inductive component 131 and the resonance capacitor C2 can be equivalent to a new inductor, and the resonance capacitor C2 and the filter capacitor C1 can be equivalent to a new capacitor. For the convenience of understanding and explanation, the new inductor equivalent to the inductive component 131 and the resonance inductor L2 is regarded as the equivalent inductor, and the new capacitor equivalent to the resonance capacitor C2 and the filter capacitor C1 is regarded as the equivalent capacitor. The reciprocal of the capacitance value of the equivalent capacitor is the sum of the reciprocals of the capacitance values of the resonance capacitor C2 and the filter capacitor C1, and the inductance value of the equivalent inductor is the sum of the inductance values of the inductive component 131 and the resonance inductor L2. That is, at this time, the resonance cavity 200 can be regarded as composed of an equivalent inductor and an equivalent capacitor.

[0055] The frequency of the oscillating wave can be calculated by the following formula:

[0056]

[0057] Among them, f is the frequency of the oscillating wave; L is the inductance value of the equivalent inductor; C is the capacitance value of the equivalent capacitor.

[0058] Regardless of whether the switch component 132 of the frequency selection module 130 is closed or not, the filter capacitor C1 always exists in the resonance cavity 200 and participates in the generation of the oscillating wave. That is, the capacitance value of the equivalent capacitor in the resonance cavity 200 remains unchanged.

[0059] As can be seen from the above formula, when the equivalent inductor in the resonance cavity 200 increases, the frequency of the oscillating wave generated by the resonance cavity 200 decreases. Therefore, when the inductive component 131 is connected in series with the resonance inductor L2 in the resonance module 120, that is, when the switch component 132 is turned off, the frequency of the oscillating wave generated by the resonance cavity 200 decreases.

[0060] The quality factor of the resonance cavity 200 can be calculated by the following formula:

[0061]

[0062] Among them, Q is the quality factor of the resonance cavity; f is the frequency of the oscillating wave; L is the inductance value of the equivalent inductor in the resonance cavity; R is the resistance value of the equivalent resistance of the devices in the resonance cavity.

[0063] As can be seen from the above formula, when the frequency of the oscillation wave generated by the resonant cavity 200 decreases, the quality factor of the resonant cavity 200 also decreases accordingly.

[0064] When a metal object enters the charging range of the wireless charging device, eddy currents are generated in the metal object. The magnetic field generated by the eddy currents will hinder the change of the original magnetic field, change the magnetic field distribution around the equivalent inductor in the resonant cavity 200, and then change the self-inductance coefficient of the equivalent inductor, thereby changing the inductance value of the equivalent inductor in the resonant cavity 200.

[0065] As can be seen from the above two formulas, when the inductance value of the equivalent inductor in the resonant cavity 200 changes, the frequency of the oscillation wave generated by the resonant cavity 200 changes, and the quality factor of the resonant cavity 200 also changes accordingly. Therefore, the detection of whether there is a metal object in the wireless charging device can be realized according to the quality factor of the resonant cavity 200. Since when a metal object enters the charging range of the wireless charging device, the resonance point generated by the resonant cavity 200 will change, and when the resonance point of the resonant cavity 200 changes, the frequency of the oscillation wave generated by the resonant cavity 200 also changes accordingly. When the resonance 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 the resonance module 120 and the electrical characteristics of the frequency selection module 140, and can be set according to actual needs in actual applications. This embodiment does not limit this.

[0066] 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 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.

[0067] Figure 5 It is an equivalent diagram of a resonant cavity during wireless charging provided by an embodiment of the present invention. When the wireless charging device performs wireless charging on the electronic device, the inductive component 131 of the frequency selection module 130 no longer participates in the generation of the oscillation wave, and at this time, the switch component 132 of the frequency selection module 130 is closed. Refer to Figure 5, at this time, the filter capacitor C1 in the filter module 110 and the resonance module 120 together form a resonance cavity 200. It should be noted that when the resonance cavity 200 is only composed of the filter capacitor C1 in the filter module 110 and the resonance module 120, the frequency of the oscillation wave generated is the charging frequency during wireless charging. At this time, the wireless charging device can charge the electrical device.

[0068] The filter module 110 of the embodiment of the present invention filters the alternating current connected between the first input terminal A and the second input terminal B. During metal object detection, the switch component 132 of the frequency selection module 130 is turned off, so that the inductive component 131 of the frequency selection module 130 provides an additional inductor for the resonance module 120, thereby changing the frequency of the oscillation wave, so that the frequency of the oscillation wave during metal object detection is different from the frequency of the oscillation wave during wireless charging. In the embodiment of the present invention, when detecting a metal object, the switch component 132 of the frequency selection module 130 is turned off to connect the inductive component 131 of the frequency selection module 130, changing the frequency of the oscillation wave generated by the wireless charging device, so that the frequency of the oscillation wave during metal object detection is different from the frequency of the oscillation wave during wireless charging, which is beneficial to avoiding the interference of the adjacent wireless charging device during the metal object detection process and improving the accuracy of metal object detection.

[0069] The working process of the resonance cavity 200 is described below, taking the structure of the resonance module 130 when the switch component 132 is closed as an example.

[0070] When electric energy enters the resonance cavity 200, the resonance capacitor C2 and the filter capacitor C1 are charged. Electric charges will accumulate between the two plates of the resonance capacitor C2 and the filter capacitor C1 to form an electric field. At this time, the resonance capacitor C2 and the filter capacitor C1 store electric field energy. As the voltage across the resonance capacitor C2 and the filter capacitor C1 gradually increases, the charging current gradually decreases. When the resonance capacitor C2 and the filter capacitor C1 are fully charged, the current is zero, and all the electric energy is converted into the electric field energy of the resonance capacitor C2 and the filter capacitor C1.

[0071] After the resonance capacitor C2 and the filter capacitor C1 are fully charged, due to the voltage existing between the two plates of the resonance capacitor C2 and the filter capacitor C1, they will start to discharge. During discharge, the electric field energy in the resonance capacitor C2 and the filter capacitor C1 is gradually converted into magnetic field energy in the resonance inductor L2. As the charges on the plates of the resonance capacitor C2 and the filter capacitor C1 gradually decrease, the discharge current gradually increases, the electric field energy continuously decreases, and the magnetic field energy continuously increases. When the resonance capacitor C2 and the filter capacitor C1 are fully discharged, the charges on the capacitor plates are zero and the electric field energy is zero. At this time, the current reaches the maximum value, and all the electric field energy is converted into the magnetic field energy of the resonance inductor L2.

[0072] Since the current in the resonant inductor L2 cannot change abruptly, after the resonant capacitor C2 and the filter capacitor C1 are discharged completely, the magnetic energy in the resonant inductor L2 will impede the decrease of the current, causing the current to continue flowing in the original direction and start to charge the resonant capacitor C2 and the filter capacitor C1 reversely. As the current gradually decreases, the magnetic energy in the resonant inductor L2 is gradually converted into the electric energy of the resonant capacitor C2 and the filter capacitor C1. When the current decreases to zero, all the magnetic energy is converted into the electric energy of the resonant capacitor C2 and the filter capacitor C1. At this time, the polarity of the charges on the two plates of the resonant capacitor C2 and the filter capacitor C1 is opposite to that during the initial charging.

[0073] After the reverse charging of the resonant capacitor C2 and the filter capacitor C1 is completed, they will start to discharge reversely and repeat the above process. The electric energy of the resonant capacitor C2 and the filter capacitor C1 and the magnetic energy of the resonant inductor L2 are continuously converted into each other, forming a periodic oscillating current.

[0074] It should be noted that when the switch component 132 is turned off, the filter capacitor C1, the resonant module 120, and the frequency selection module 130 in the filter module 110 together form a resonant cavity 200. The electric energy entering the resonant cavity 200 is continuously converted between the electric energy of the resonant capacitor C2 and the filter capacitor C1 and the magnetic energy of the resonant inductor L2 and the inductive component 131 of the frequency selection module 130 to form a periodic oscillating current.

[0075] Figure 6 It is a schematic diagram of another wireless charging device provided by an embodiment of the present invention. On the basis of the above embodiment, optionally, referring to Figure 6 , the wireless charging device can also be provided with a switch module 160.

[0076] Among them, the switch module 160 is connected in parallel with the filter capacitor C1. The switch module 160 is configured to maintain a conducting state during metal object detection.

[0077] Since the reciprocal of the total capacitance value of the capacitors connected in series in the circuit is the sum of the reciprocals of the capacitances of each capacitor in the circuit, that is, the more the number of capacitors connected in series in the circuit, the smaller the total capacitance value in the circuit.

[0078] According to the oscillation wave frequency calculation formula:

[0079]

[0080] where f is the frequency of the oscillation wave; L is the inductance value of the equivalent inductor; C is the capacitance value of the equivalent capacitor.

[0081] It can be known that the frequency of the oscillation wave during metal object detection is related to the inductance value and capacitance value in the circuit, and when the inductance value and / or capacitance value in the circuit is larger, the frequency of the oscillation wave during metal object detection is smaller.

[0082] Therefore, when detecting a metallic object, keeping the switch module 160 turned on and short-circuiting the filter capacitor C1 is beneficial to reducing the frequency of the oscillation wave during metallic object detection, and further making the frequency of the oscillation wave during metallic object detection different from the frequency of the oscillation wave during wireless charging.

[0083] Exemplarily, the switch module 160 can be a transistor switch, a thyristor switch, a solid-state relay, an integrated electronic switch, etc., and those skilled in the art can select and configure according to design requirements and other factors.

[0084] Figure 7 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 wireless charging device further includes: a control module 140.

[0085] The control module 140 is respectively connected to the resonant module 120 and the switch assembly 132; the control module 140 is configured to control the switch assembly 132 to turn off during metallic object detection.

[0086] Specifically, the control module 140 enables the switch assembly 132 when the wireless charging device is performing wireless charging, so that the switch assembly 132 is closed; the control module 140 stops enabling the switch assembly 132 when the wireless charging device is detecting a metallic object, so that the switch assembly 132 is turned off.

[0087] Figure 8 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 step-down circuit 142.

[0088] The processor 141 is also connected to the switch assembly 132 of the frequency selection module 130, the input end of the step-down circuit 142 is connected to the resonant module 120, and the output end of the step-down circuit 142 is connected to the processor 141; the step-down circuit 142 is configured to reduce the waveform voltage of the oscillation wave generated by the resonant module 120; the processor 141 is configured to control the switch assembly 132 to turn off during metallic object detection. In this embodiment, the step-down circuit 142 can be connected to any position of the resonant module 120.

[0089] In this embodiment, the step-down 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.

[0090] Specifically, the filtering module 110 filters the alternating current connected to the first input terminal A and the second input terminal B, and outputs the filtered alternating current to the resonance module 120. When the wireless charging device wirelessly charges the electronic device, the processor 141 enables the switch component 132 of the frequency selection module 130; when the wireless charging device detects whether there is a metal object within its charging range, the processor 141 stops enabling the switch component 132 of the frequency selection module 130.

[0091] After the processor 141 enables the frequency selection module 130, the buck circuit 142 generates waveform data based on the oscillation wave generated by the resonant cavity 200. The processor 141 acquires the waveform data generated by the buck circuit 142, and calculates the quality factor of the resonant cavity 200 according to the waveform data. The processor 141 compares the calculated quality factor of the resonant cavity with a preset range. When the quality factor of the resonant 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 resonant 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.

[0092] Exemplarily, when the processor 141 calculates the quality factor of the resonant cavity according to the waveform data, the processor 141 calculates the frequency of the oscillation wave from the waveform data. Based on the known frequency of the oscillation wave, the processor 141 calculates the quality factor of the resonant cavity according to the following formula:

[0093]

[0094] Where Q is the quality factor of the resonant cavity; f is the frequency of the oscillation 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.

[0095] Based on the above embodiments, optionally, continuing to refer to Figure 8 , the wireless charging device further includes: an inverter module 150.

[0096] 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, and the control terminal of the inverter module 150 is connected to the control module 140; the inverter module 150 is used to convert the direct current output by the DC power supply 10 into alternating current.

[0097] Exemplarily, the DC power supply 10 can be any suitable DC energy storage device or power generation device, such as a rechargeable battery, a fuel cell, and a photovoltaic panel, etc.

[0098] Specifically, when detecting whether there is a metal object within the charging range of the wireless charging device, 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 the required electrical energy for the resonance module 120. It should be noted that the preset time is the pre-set operating time of the inverter module 150 during the metal object detection process, which can be set according to actual needs in practical applications, and this embodiment does not limit it. 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.

[0099] Based on the above embodiments, optionally, continue to refer to Figure 8 , the inverter module 150 includes: a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4.

[0100] 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 terminals 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.

[0101] Among them, 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 transistor switches, thyristor switches, solid state relays, or integrated electronic switches, etc.

[0102] The embodiment of the present invention also provides a wireless charging system. Figure 9 It 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.

[0103] It should be noted that the wireless charging system 1000 provided by the embodiment 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.

[0104] An embodiment of the present invention further provides a wireless charging method. Figure 10 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. The wireless charging device includes a frequency selection module, and the frequency selection module includes a switch component. Refer to Figure 10 The wireless charging method includes:

[0105] S110. Provide alternating current.

[0106] Exemplarily, in combination with Figure 8 , the control module drives the inverter module to operate for a preset time. When the inverter module is operating, it converts the direct current provided by the DC power supply into alternating current and inputs the alternating current into the first input terminal and the second input terminal.

[0107] It should be noted that when the preset time is reached, the control module stops driving the inverter module, and the inverter module is completely turned off. At this time, the inverter module is equivalent to an open circuit.

[0108] S120. Keep the switch component off during metal object detection.

[0109] Specifically, during metal object detection, keep the switch component off so that during metal object detection, the inductive component provides an additional inductor for the resonant module, thereby changing the resonance point when the branch of the resonant capacitor and the resonant inductor oscillates. It should be noted that during metal object detection, the control module stops driving the inverter module, that is, the inverter module is equivalent to an open circuit.

[0110] Among them, the control module can detect whether there is a metal object through the quality factor of the oscillation wave generated by the wireless charging system.

[0111] The frequency of the oscillation wave can be calculated by the following formula:

[0112]

[0113] Among them, f is the frequency of the oscillation wave; L is the inductance value in the resonant cavity; C is the capacitance value in the resonant cavity.

[0114] On the basis of knowing the frequency of the oscillation wave, the quality factor of the resonant cavity can be calculated according to the following formula:

[0115]

[0116] Among them, Q is the quality factor of the resonant cavity; f is the frequency of the oscillation 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.

[0117] When the quality factor 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 is within the preset range, it is considered that there is no metal object within the charging range of the wireless charging device.

[0118] Figure 11 It is a flowchart of another wireless charging method provided by an embodiment of the present invention. On the basis of the above embodiments, optionally, referring to Figure 11 , after maintaining the switch component off during metal object detection, it further includes:

[0119] S130. Maintain the switch component conducting during wireless charging.

[0120] Specifically, when there is no metal object within the charging range of the wireless charging device, the wireless charging device can perform wireless charging normally. At this time, the switch component of the frequency selection module is enabled, so as to short-circuit the inductive component of the frequency selection module. At this time, the inductive component of the frequency selection module no longer provides additional inductance for the resonant module, and the wireless charging device performs wireless charging on the electronic device.

[0121] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, which is not limited herein.

[0122] 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 principle 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; A filtering module, the filtering module being connected to the first input terminal and the second input terminal, the filtering module including a filtering capacitor, and the filtering module being configured to filter the input alternating current; A resonance module, the resonance module including a resonance inductor and a resonance capacitor connected in series, and a branch where the resonance inductor and the resonance capacitor are located being connected in parallel with the filtering capacitor, and the resonance module being configured to generate an oscillation wave based on the filtered alternating current; A frequency selection module, the frequency selection module including an inductive component and a switching component connected in parallel, the inductive component being connected in series to the branch where the resonance inductor and the resonance capacitor are located, and the switching component being configured to maintain an off state when detecting a metal object.

2. The wireless charging device according to claim 1, wherein The inductive component is connected between the resonance inductor and the filtering capacitor.

3. The wireless charging device according to claim 1, characterized in that, The inductive component is connected between the resonance capacitor and the filtering capacitor.

4. The wireless charging device according to claim 1, characterized in that, The inductive component is connected between the resonance inductor and the resonance capacitor.

5. The wireless charging device according to any one of claims 1-4, characterized in that, The inductive component includes: at least one frequency selection inductor; Each of the frequency selection inductors is connected in series, and a branch where each of the frequency selection inductors is located is connected in parallel with the switching component, or each of the frequency selection inductors is respectively connected in parallel with a switching component.

6. The wireless charging device according to any one of claims 1-4, 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.

7. The wireless charging device according to any one of claims 1 to 4, characterized in that, The switching component includes: one of a transistor switch, a thyristor switch, a solid-state relay or an integrated electronic switch.

8. The wireless charging device according to any one of claims 1-4, characterized in that, Further comprising: A control module; The control module is respectively connected to the resonance module and the switching component; The control module is configured to control the switching component to turn off when detecting a metal object.

9. The wireless charging device according to claim 8, wherein, The control module includes: a processor and a step-down circuit; The processor is connected to the switching component of the frequency selection module, an input end of the step-down circuit is connected to the resonance module, and an output end of the step-down circuit is connected to the processor; The step-down circuit is configured to reduce the waveform voltage of the oscillation wave generated by the resonance module; the processor is configured to control the switching component to turn off when detecting a metal object.

10. The wireless charging device according to claim 8, wherein Further comprising: An inversion module; A direct current input end of the inversion module is connected to a direct current power supply, a first output end of the inversion module is connected to the first input terminal, a second output end of the inversion module is connected to the second input terminal, and a control end of the inversion module is connected to the control module; The inversion module is used to convert the direct current output by the direct current power supply into an alternating current.

11. The wireless charging device according to claim 10, characterized in that, The inversion 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 electrode 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 electrode 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 electrode 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 electrode 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. The second end of the second switch and the second end of the fourth switch are also grounded.

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

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

14. The wireless charging method according to claim 13, wherein After maintaining the switch assembly off during metal object detection, further comprising: Maintaining the switch assembly on during wireless charging.

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