A wireless charging device and system

Abstract

The utility model discloses a wireless charging device and system. The wireless charging device comprises: a first input end and a second input end are connected with alternating current; a filter module is connected with the first input end and the second input end, and the filter module comprises a filter capacitor; the filter module is configured to filter the alternating current; a resonance module comprises a resonance inductor and a resonance capacitor connected in series; a branch where the resonance inductor and the resonance capacitor are located is connected in parallel with the filter capacitor; the resonance module is configured to generate an oscillation wave based on the filtered alternating current; a frequency selection module comprises an inductive component and a switch component connected in parallel; the inductive component is connected in series with 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 metal objects. The wireless charging device provided by the utility model embodiment is beneficial to avoiding interference of the wireless charging device during the metal object detection process and improving the accuracy of the metal object detection.

Description

Technical Field

[0001] This utility model relates to the field of wireless charging technology, and in particular to a wireless charging device and system. Background Technology

[0002] With further technological advancements, wireless power transfer has emerged as an efficient and convenient mechanism for powering or charging battery-powered mobile devices such as mobile phones, tablet PCs, digital cameras, and MP3 players. Wireless power transfer systems typically consist of a primary-side transmitter and a secondary-side receiver. The primary-side transmitter is magnetically coupled to the secondary-side receiver.

[0003] Before wireless power transmission, the wireless power transmission system will detect whether there are any metal objects within the power transmission range that may adversely affect the power transmission, in order to avoid the adverse effects of foreign objects on power transmission.

[0004] However, when two wireless chargers are close together, they interfere with each other, resulting in poor accuracy in metal detection. Utility Model Content

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

[0006] According to one aspect of the present invention, a wireless charging device is provided, the wireless charging device comprising:

[0007] The first input terminal and the second input terminal are connected to AC power.

[0008] A filtering module is connected to the first input terminal and the second input terminal. The filtering module includes a filtering capacitor and is configured to filter the incoming AC power.

[0009] The resonant module includes a resonant inductor and a resonant capacitor connected in series. The branch containing the resonant inductor and the resonant capacitor is connected in parallel with the filter capacitor. The resonant module is configured to generate an oscillating wave based on the filtered alternating current.

[0010] A frequency selection module includes an inductive component and a switching component connected in parallel. The inductive component is connected in series to the branch containing the resonant inductor and the resonant capacitor. The frequency selection module is configured to remain in an off state when detecting a metal object.

[0011] Optionally, the inductive component is connected between the resonant inductor and the filter capacitor.

[0012] Optionally, the inductive component is connected between the resonant capacitor and the filter 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] Each of the frequency-selective inductors is connected in series, and the branch containing each frequency-selective inductor is connected in parallel with the switching assembly, or each frequency-selective inductor is connected in parallel with a switching assembly.

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

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

[0018] The control module is connected to the resonant module and the switching assembly respectively; the control module is configured to control the switching assembly to turn off when a metal object is detected.

[0019] Optionally, the control module includes: a processor and a step-down circuit;

[0020] The processor is connected to the switching component of the frequency selection module, the input terminal of the buck circuit is connected to the resonant module, and the output terminal of the buck circuit is connected to the processor.

[0021] The step-down 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 assembly to turn off when a metal object is detected.

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

[0023] 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, and the control terminal of the inverter module is connected to the control module.

[0024] The inverter module is used to convert the DC power output from the DC power supply into AC power.

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

[0026] The first terminal of the first switch is connected to the positive terminal of the DC power supply. The second terminal of the first switch is connected to the first terminal of the second switch. The second terminal of the second switch is connected to the negative terminal of the DC power supply. The first terminal of the second switch is also connected to the first input terminal. The first terminal of the third switch is connected to the positive terminal of the DC power supply. The second terminal of the third switch is connected to the first terminal of the fourth switch. The second terminal of the fourth switch is connected to the negative terminal of the DC power supply. The first terminal 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 terminals of the second switch and the fourth switch are also grounded.

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

[0028] The filtering module of this embodiment filters the AC power input between the first and second input terminals. During metal detection, the switching component of the frequency selection module is turned off, allowing the inductive component of the frequency selection module to provide additional inductance to the resonant module, thereby changing the frequency of the oscillation wave. This ensures that the frequency of the oscillation wave during metal detection differs from the frequency of the oscillation wave during wireless charging. In this embodiment, by turning off the switching component of the frequency selection module during metal detection, the inductive component of the frequency selection module changes the frequency of the oscillation wave generated by the wireless charging device, thus differentiating the frequency of the oscillation wave during metal detection from that during wireless charging. This helps avoid interference from nearby wireless charging devices during metal detection, improving the accuracy of metal detection.

[0029] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a wireless charging device provided in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of another wireless charging device provided in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model;

[0034] Figure 4 This is an equivalent diagram of a resonant cavity for metal detection provided in an embodiment of the present invention;

[0035] Figure 5 This is an equivalent diagram of a resonant cavity during wireless charging provided in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model;

[0037] Figure 7 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model;

[0038] Figure 8 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model;

[0039] Figure 9 This is a schematic diagram of a wireless charging system provided in an embodiment of the present invention;

[0040] Figure 10 This is a flowchart of a wireless charging method performed by the wireless charging device provided in this embodiment of the present invention;

[0041] Figure 11 This is a flowchart of another wireless charging method performed by the wireless charging device provided in this embodiment of the present invention. Detailed Implementation

[0042] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0043] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model 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 where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] This utility model provides a wireless charging device. This wireless charging device is suitable for wireless charging of electronic devices. In this embodiment, the control module enables the frequency selection module when detecting a metal object, causing the frequency selection module to change the frequency of the oscillation wave generated by the wireless charging device. This makes the frequency of the oscillation wave during metal object detection different from the frequency of the oscillation wave during wireless charging, which helps to avoid interference from nearby wireless charging devices during metal object detection and improves the accuracy of metal object detection. Figure 1 This is a schematic diagram of a wireless charging device provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another wireless charging device provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of yet another wireless charging device provided in an embodiment of this utility model. (Refer to...) Figure 1 , Figure 2 and Figure 3 The wireless charging device includes a filter module 110, a resonant module 120, and a frequency selection module 130.

[0045] The first input terminal A and the second input terminal B are connected to AC power. The filter module 110 is connected to the first input terminal A and the second input terminal B. The filter module 110 includes a filter capacitor C1 and is configured to filter the AC power. The resonant module 120 includes a resonant inductor L2 and a resonant capacitor C2 connected in series. The branch containing the resonant inductor L2 and the resonant capacitor C2 is connected in parallel with the filter capacitor C1. The resonant module 120 is configured to generate an oscillation wave based on the filtered AC power. The frequency selection module 130 includes an inductive component 131 and a switching component 132 connected in parallel. The inductive component 131 is connected in series with the branch containing the resonant inductor L2 and the resonant capacitor C2. The frequency selection module 130 is configured to remain in the off state when detecting a metal object.

[0046] For example, combined Figure 1 The inductive component 131 can be connected between the resonant inductor L2 and the filter capacitor C1; combined with Figure 2 The inductive component 131 can also be connected between the resonant capacitor C2 and the filter capacitor C1; combined with Figure 3 The inductive component 131 can also be connected between the resonant inductor L2 and the resonant capacitor C2. The inductive component 131 can be composed of at least one frequency-selective inductor L3. When the inductive component 131 has at least two frequency-selective inductors L3, each frequency-selective inductor L3 can be connected in series and then connected in parallel with the switching component 132, or each frequency-selective inductor L3 can be connected in parallel with a separate switching component 132. The switching component 132 can be a transistor switch, a thyristor switch, a solid-state relay, or an integrated electronic switch, etc. Optionally, referring to... Figure 1 The filter module 110 can also be equipped with at least one filter inductor L1, which is connected in series with the filter capacitor C1.

[0047] Specifically, the filtering module 110 filters the AC power input between the first input terminal A and the second input terminal B, and outputs the filtered AC power to the resonant 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 the presence of metal objects within its charging range, the switch component 132 of the frequency selection module 130 is turned off. The timing of the wireless charging device detecting the presence of metal objects within its charging range can be, for example, before the wireless charging device wirelessly charges the electronic device. Figure 4 This is an equivalent diagram of a resonant cavity for metal detection provided in this embodiment of the present invention. When the switching component 132 of the frequency selection module 130 is turned off, the inductive component 131 in the frequency selection module 130 provides additional inductance to the resonant 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 resonant module 120 and the inductive component 131 of the frequency selection module 130 together constitute the resonant cavity 200.

[0048] When electrical energy enters the resonant cavity 200, it oscillates within the cavity, generating an oscillating wave. The quality factor of the resonant cavity 200 can then be calculated using the frequency of the oscillating wave generated within it.

[0049] In this context, the inductive component 131 exhibits inductive properties. When the inductive component 131, the filter capacitor C1 in the filter module 110, and the resonant module 120 constitute the resonant cavity 200, the inductive component 131 and the resonant capacitor C2 can be considered equivalent to a new inductor, and the resonant capacitor C2 and the filter capacitor C1 can be considered equivalent to a new capacitor. For ease of understanding and explanation, the new inductor equivalent to the inductive component 131 and the resonant inductor L2 is referred to as the equivalent inductance, and the new capacitor equivalent to the resonant capacitor C2 and the filter capacitor C1 is referred to 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 resonant capacitor C2 and the filter capacitor C1, and the inductance value of the equivalent inductance is the sum of the inductance values ​​of the inductive component 131 and the resonant inductor L2. That is, the resonant cavity 200 can be considered to be composed of an equivalent inductance and an equivalent capacitance.

[0050] The frequency of the oscillating wave can be calculated using the following formula:

[0051]

[0052] Where f is the frequency of the oscillation wave; L is the inductance of the equivalent inductance; and C is the capacitance of the equivalent capacitance.

[0053] Regardless of whether the switching component 132 of the frequency selection module 130 is closed, the filter capacitor C1 always exists within the resonant cavity 200 and participates in the generation of the oscillation wave. That is, the value of the equivalent capacitance within the resonant cavity 200 remains unchanged.

[0054] As can be seen from the above formula, when the equivalent inductance in the resonant cavity 200 increases, the frequency of the oscillation wave generated by the resonant cavity 200 decreases. Therefore, when the inductive component 131 is connected in series with the resonant inductor L2 in the resonant module 120, that is, when the switching component 132 is turned off, the frequency of the oscillation wave generated by the resonant cavity 200 decreases.

[0055] The quality factor of the resonant cavity 200 can be calculated using the following formula:

[0056]

[0057] Where Q is the quality factor of the resonant cavity; f is the frequency of the oscillation wave; L is the inductance of the equivalent inductance in the resonant cavity; and R is the resistance of the equivalent resistance of the devices in the resonant cavity.

[0058] 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.

[0059] When a metal object enters the charging range of a wireless charging device, eddy currents are generated within the metal object. The magnetic field generated by the eddy currents will hinder the change of the original magnetic field, thereby changing the magnetic field distribution around the equivalent inductor in the resonant cavity 200, which in turn changes the self-inductance coefficient of the equivalent inductor, thus causing the inductance value of the equivalent inductor in the resonant cavity 200 to change.

[0060] As shown in the two formulas above, when the inductance of the equivalent inductance within 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 presence of metal objects within the wireless charging device can be detected based on the quality factor of the resonant cavity 200. Since the resonant point generated by the resonant cavity 200 changes when a metal object enters the charging range of the wireless charging device, the frequency of the oscillation wave generated by the resonant cavity 200 also changes accordingly. Different resonant points result in different quality factors for the resonant cavity 200. Therefore, the presence of metal objects within the charging range of the wireless charging device can be determined based on the quality factor of the resonant cavity 200. When the quality factor of the resonant cavity 200 is outside a preset range, it indicates the presence of metal objects within the charging range of the wireless charging device; when the quality factor of the resonant cavity 200 is within the preset range, it indicates the absence of metal objects within the charging range of the wireless charging device. 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 within the charging range of the wireless charging device. The preset range depends on the electrical characteristics of the resonant module 120 and the electrical characteristics of the frequency selection module 140. In actual applications, it can be set according to actual needs. This embodiment does not limit it.

[0061] When a metal object is present within the charging range of the wireless charging device, the quality factor of the resonant cavity 200 is detected until no metal object is found within the charging range. Once no metal object is present within the charging range, the wireless charging device proceeds with normal wireless charging.

[0062] Figure 5 This is an equivalent diagram of a resonant cavity during wireless charging according to an embodiment of the present invention. When the wireless charging device wirelessly charges an 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 switching 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 resonant module 120 together constitute the resonant cavity 200. It should be noted that when the resonant cavity 200 is composed only of the filter capacitor C1 in the filter module 110 and the resonant 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 device.

[0063] The filtering module 110 of this embodiment filters the AC power input between the first input terminal A and the second input terminal B. During metal detection, the switching component 132 of the frequency selection module 130 is turned off, allowing the inductive component 131 of the frequency selection module 130 to provide additional inductance to the resonant module 120, thereby changing the frequency of the oscillation wave. This ensures that the frequency of the oscillation wave during metal detection is different from the frequency of the oscillation wave during wireless charging. In this embodiment, when detecting metal, the switching component 132 of the frequency selection module 130 is turned off, allowing the inductive component 131 of the frequency selection module 130 to be connected. This changes the frequency of the oscillation wave generated by the wireless charging device, thus differentiating the frequency of the oscillation wave during metal detection from the frequency of the oscillation wave during wireless charging. This helps avoid interference from nearby wireless charging devices during metal detection, improving the accuracy of metal detection.

[0064] The following describes the working process of the resonant cavity 200, taking the resonant module 130 configured when the switch assembly 132 is closed as an example.

[0065] When electrical energy enters the resonant cavity 200, the resonant capacitor C2 and the filter capacitor C1 are charged. Charge accumulates between the plates of the resonant capacitor C2 and the filter capacitor C1, forming an electric field. At this time, the resonant capacitor C2 and the filter capacitor C1 store electric field energy. As the voltage across the resonant capacitor C2 and the filter capacitor C1 gradually increases, the charging current gradually decreases. When the resonant capacitor C2 and the filter capacitor C1 are fully charged, the current is zero, and all the electrical energy is converted into the electric field energy of the resonant capacitor C2 and the filter capacitor C1.

[0066] After the resonant capacitor C2 and the filter capacitor C1 have finished charging, they will begin to discharge due to the voltage between their plates. During discharge, the electric field energy in the resonant capacitor C2 and the filter capacitor C1 is gradually converted into the magnetic field energy in the resonant inductor L2. As the charge on the plates of the resonant capacitor C2 and the filter capacitor C1 gradually decreases, the discharge current gradually increases, the electric field energy continuously decreases, and the magnetic field energy continuously increases. When the resonant capacitor C2 and the filter capacitor C1 have completely discharged, the charge on the capacitor plates is zero, the electric field energy is zero, and the current reaches its maximum value. At this point, all the electric field energy has been converted into the magnetic field energy of the resonant inductor L2.

[0067] Since the current in the resonant inductor L2 cannot change abruptly, after the resonant capacitor C2 and the filter capacitor C1 have finished discharging, the magnetic field energy in the resonant inductor L2 will hinder the decrease in current, causing the current to continue flowing in its original direction and begin to charge the resonant capacitor C2 and the filter capacitor C1 in the reverse direction. As the current gradually decreases, the magnetic field energy in the resonant inductor L2 is gradually converted into the electric field energy of the resonant capacitor C2 and the filter capacitor C1. When the current decreases to zero, all the magnetic field energy is converted into the electric field energy of the resonant capacitor C2 and the filter capacitor C1. At this time, the polarity of the charges on the plates of the resonant capacitor C2 and the filter capacitor C1 is opposite to that at the beginning of the charging process.

[0068] After the resonant capacitor C2 and the filter capacitor C1 have completed their reverse charging, they will begin to discharge in reverse, repeating the above process. The electric field energy of the resonant capacitor C2 and the filter capacitor C1 and the magnetic field energy of the resonant inductor L2 are constantly being converted into each other, forming a periodic oscillating current.

[0069] It should be noted that when the switching component 132 is turned off, the filter capacitor C1 in the filter module 110, the resonant module 120 and the frequency selection module 130 together form the resonant cavity 200. The electrical energy entering the resonant cavity 200 is constantly converted between the electric field energy of the resonant capacitor C2 and the filter capacitor C1 and the magnetic field energy of the resonant inductor L2 and the inductive component 131 of the frequency selection module 130, so as to form a periodic oscillating current.

[0070] Figure 6 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model. Optionally, based on the above embodiments, refer to... Figure 6 The wireless charging device can also be equipped with a switch module 160.

[0071] The switch module 160 is connected in parallel with the filter capacitor C1. The switch module 160 is configured to remain in the on state during metal detection.

[0072] Since the reciprocal of the total capacitance of the capacitors connected in series in a circuit is the sum of the reciprocals of the individual capacitances in the circuit, the more capacitors connected in series in a circuit, the smaller the total capacitance of the circuit.

[0073] Based on the formula for calculating the frequency of oscillating waves:

[0074]

[0075] Where f is the frequency of the oscillation wave; L is the inductance of the equivalent inductance; and C is the capacitance of the equivalent capacitance.

[0076] It can be seen that the frequency of the oscillation wave during metal detection is related to the inductance and capacitance values ​​in the circuit, and the larger the inductance and / or capacitance values ​​in the circuit, the smaller the frequency of the oscillation wave during metal detection.

[0077] Therefore, keeping the switch module 160 on during metal detection and shorting the filter capacitor C1 helps to reduce the frequency of the oscillation wave during metal detection, further distinguishing the frequency of the oscillation wave during metal detection from the frequency of the oscillation wave during wireless charging.

[0078] For example, the switch module 160 can be a transistor switch, thyristor switch, solid-state relay or integrated electronic switch, etc., and those skilled in the art can select and configure it according to design requirements and other factors.

[0079] Figure 7 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model. Optionally, based on the above embodiments, refer to... Figure 7 The wireless charging device also includes a control module 140.

[0080] The control module 140 is connected to the resonant module 120 and the switching assembly 132 respectively; the control module 140 is configured to control the switching assembly 132 to turn off when a metal object is detected.

[0081] Specifically, the control module 140 enables the switch assembly 132 when the wireless charging device is wirelessly charging, thereby closing the switch assembly 132; the control module 140 stops enabling the switch assembly 132 when the wireless charging device detects a metal object, thereby turning off the switch assembly 132.

[0082] Figure 8 This is a schematic diagram of another wireless charging device provided in an embodiment of the present utility model. Optionally, based on the above embodiments, refer to... Figure 8 The control module 140 includes a processor 141 and a step-down circuit 142.

[0083] The processor 141 is also connected to the switching assembly 132 of the frequency selection module 130. The input of the buck circuit 142 is connected to the resonant module 120, and the output 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 generated by the resonant module 120. The processor 141 is configured to control the switching assembly 132 to turn off when a metal object is detected. In this embodiment, the buck circuit 142 can be connected to any location of the resonant module 120.

[0084] In this embodiment, the step-down circuit 142 is used to reduce the waveform voltage of the oscillation wave so as to convert the oscillation wave into waveform data that can be acquired by the analog-to-digital converter in the processor 141.

[0085] Specifically, the filtering module 110 filters the AC power input between the first input terminal A and the second input terminal B, and outputs the filtered AC power to the resonant module 120. When the wireless charging device wirelessly charges the electronic device, the processor 141 enables the switching component 132 of the frequency selection module 130; when the wireless charging device detects the presence of metal objects within its charging range, the processor 141 stops enabling the switching component 132 of the frequency selection module 130.

[0086] 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 based on 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.

[0087] For example, when processor 141 calculates the quality factor of the resonant cavity based on waveform data, processor 141 calculates the frequency of the oscillation wave from the waveform data. Given the frequency of the oscillation wave, processor 141 calculates the quality factor of the resonant cavity according to the following formula:

[0088]

[0089] Where Q is the quality factor of the resonant cavity; f is the frequency of the oscillation wave; L is the inductance of the equivalent inductance in the resonant cavity; and R is the resistance of the equivalent resistance of the devices in the resonant cavity.

[0090] Based on the above embodiments, optionally, refer to... Figure 8 The wireless charging device also includes an inverter module 150.

[0091] 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 DC power output from the DC power supply 10 into AC power.

[0092] For example, the DC power supply 10 can be any suitable DC energy storage or power generation device, such as a rechargeable battery, fuel cell, and photovoltaic panel.

[0093] Specifically, when detecting the presence of a metal object within the charging range of the wireless charging device, the control module 140 drives the inverter module 150 to run for a preset time to convert the DC power output from the DC power supply 10 into AC power, thereby providing the required power to the resonant module 120. It should be noted that the preset time is a pre-set running time of the inverter module 150 during the metal object detection process. In actual applications, this time can be set according to actual needs; this embodiment does not impose any restrictions on this. When the control module 140 stops driving the inverter module 150, the inverter module 150 is completely turned off, at which point the inverter module 150 is equivalent to an open circuit.

[0094] Based on the above embodiments, optionally, 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.

[0095] The first terminal of the first switch S1 is connected to the positive terminal of the DC power supply 10. The second terminal of the first switch S1 is connected to the first terminal of the second switch S2. The second terminal of the second switch S2 is connected to the negative terminal of the DC power supply 10. The first terminal of the second switch S2 is also connected to the first input terminal A. The first terminal of the third switch S3 is connected to the positive terminal of the DC power supply 10. The second terminal of the third switch S3 is connected to the first terminal of the fourth switch S4. The second terminal of the fourth switch S4 is connected to the negative terminal of the DC power supply 10. The first terminal 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. The second terminals of the second switch S2 and the fourth switch S4 are also grounded.

[0096] 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 the inverter module 150 is open-circuited at this time. For example, 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.

[0097] This utility model embodiment also provides a wireless charging system. Figure 9 This is a schematic diagram of a wireless charging system provided in an embodiment of this utility model. (Refer to...) Figure 9 The wireless charging system 1000 includes at least one wireless charging device 100 provided in any of the embodiments.

[0098] It should be noted that the wireless charging system 1000 provided in this embodiment of the present invention has the beneficial effects of the wireless charging device 100 provided in any of the above embodiments, which will not be repeated here.

[0099] This utility model embodiment also provides a wireless charging method. Figure 10 This is a flowchart illustrating a wireless charging method performed by the wireless charging device provided in this embodiment of the present invention. This wireless charging method is performed by the wireless charging device provided in any of the above embodiments. The wireless charging device includes a frequency selection module, and the frequency selection module includes a switching component. (Refer to...) Figure 10 The wireless charging method includes:

[0100] S110, provides AC power.

[0101] For example, combined Figure 8 The control module drives the inverter module to run for a preset time. During operation, the inverter module converts the DC power supplied by the DC power source into AC power and inputs the AC power to the first and second input terminals.

[0102] 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 shut down. At this time, the inverter module is equivalent to an open circuit.

[0103] S120. Keep the switching assembly off during metal detection.

[0104] Specifically, during metal detection, the switching components remain off, allowing the inductive components to provide additional inductance to the resonant module during metal detection, thereby changing the resonant point of the branch containing the resonant capacitor and inductor during oscillation. It should be noted that during metal detection, the control module stops driving the inverter module, meaning the inverter module is effectively open-circuited.

[0105] The control module can detect the presence of metal objects by using the quality factor of the oscillation waves generated by the wireless charging system.

[0106] The frequency of the oscillating wave can be calculated using the following formula:

[0107]

[0108] Where f is the frequency of the oscillation wave; L is the inductance of the resonant cavity; and C is the capacitance of the resonant cavity.

[0109] Given the frequency of the oscillating wave, the quality factor of the resonant cavity can be calculated using the following formula:

[0110]

[0111] Where Q is the quality factor of the resonant cavity; f is the frequency of the oscillation wave; L is the inductance of the equivalent inductance in the resonant cavity; and R is the resistance of the equivalent resistance of the devices in the resonant cavity.

[0112] When the quality factor is outside the preset range, it is assumed 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 assumed that there is no metal object within the charging range of the wireless charging device.

[0113] Figure 11 This is a flowchart of another wireless charging method performed by the wireless charging device provided in this embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 11 After keeping the switching assembly off during metal detection, it also includes:

[0114] S130, Maintain the switching component on during wireless charging.

[0115] Specifically, when there are no metal objects within the charging range of the wireless charging device, the wireless charging device can perform wireless charging normally. At this time, the switching component of the frequency selection module is enabled, thereby short-circuiting the inductive component of the frequency selection module. At this time, the inductive component of the frequency selection module no longer provides additional inductance to the resonant module, and the wireless charging device wirelessly charges the electronic device.

[0116] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0117] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. 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 this utility model should be included within the scope of protection of this utility model.

Claims

1. A wireless charging device, characterized in that, include: The first input terminal and the second input terminal are connected to AC power. A filtering module is connected to the first input terminal and the second input terminal. The filtering module includes a filtering capacitor and is configured to filter the incoming AC power. The resonant module includes a resonant inductor and a resonant capacitor connected in series. The branch containing the resonant inductor and the resonant capacitor is connected in parallel with the filter capacitor. The resonant module is configured to generate an oscillating wave based on the filtered alternating current. A frequency selection module includes an inductive component and a switching component connected in parallel. The inductive component is connected in series to the branch containing the resonant inductor and the resonant capacitor. The switching component is configured to remain in an off state when a metal object is detected.

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

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

4. The wireless charging device according to claim 1, characterized in that, The inductive component is connected between the resonant inductor and the resonant 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-selective inductor; Each of the frequency-selective inductors is connected in series, and the branch containing each frequency-selective inductor is connected in parallel with the switching assembly, or each frequency-selective inductor is connected in parallel with a switching assembly.

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, which is connected in series with the filtering capacitor.

7. The wireless charging device according to any one of claims 1-4, characterized in that, The switching assembly includes one of the following: 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, Also includes: Control module; The control module is connected to the resonant module and the switching assembly, respectively. The control module is configured to control the switching assembly to turn off when a metal object is detected.

9. The wireless charging device according to claim 8, characterized in that, The control module includes: a processor and a step-down circuit; The processor is connected to the switching component of the frequency selection module, the input terminal of the buck circuit is connected to the resonant module, and the output terminal of the buck circuit is connected to the processor. The step-down 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 assembly to turn off when a metal object is detected.

10. The wireless charging device according to claim 8, characterized in that, Also includes: Inverter 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, and the control terminal of the inverter module is connected to the control module. The inverter module is used to convert the DC power output from the DC power supply into AC power.

11. The wireless charging device according to claim 10, characterized in that, The inverter module includes: a first switch, a second switch, a third switch, and a fourth switch; The first terminal of the first switch is connected to the positive terminal of the DC power supply. The second terminal of the first switch is connected to the first terminal of the second switch. The second terminal of the second switch is connected to the negative terminal of the DC power supply. The first terminal of the second switch is also connected to the first input terminal. The first terminal of the third switch is connected to the positive terminal of the DC power supply. The second terminal of the third switch is connected to the first terminal of the fourth switch. The second terminal of the fourth switch is connected to the negative terminal of the DC power supply. The first terminal 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 terminals of the second switch and the fourth switch are also grounded.

12. A wireless charging system, characterized in that, It includes at least one wireless charging device as described in any one of claims 1-11.

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