Voltage switching circuit and method, power adapter and storage medium

Abstract

The invention relates to a voltage switching circuit and method, a power adapter and a storage medium. The voltage switching circuit comprises an input end and an output end; the plurality of resonant transformers are arranged between the input end and the output end in parallel; one end of the switching circuit is connected with the input end, and the other end of the switching circuit is connected with the resonant transformers; wherein a plurality of first connecting lines are arranged between the input end and the plurality of resonant transformers, and under the condition that the switching circuit is in different switching states, at least one of the plurality of first connecting lines is conducted; and the number of the first connecting lines conducted in different switch states is different. According to the embodiment of the invention, the flexibility of the voltage switching circuit can be improved, the light load efficiency of the voltage switching circuit is improved, the light load loss is reduced, and the sustainable development of energy consumption is further met.

Description

Technical Field

[0001] The present disclosure relates to the field of charging technologies, and in particular, to a voltage switching circuit and method, a power adapter, and a storage medium. Background Art

[0002] With the development of fast charging technologies, power adapters are gradually trending towards high power and miniaturization. To achieve the goal of high power and miniaturization of power adapters such as mobile phone chargers, it is necessary to improve the power density of the charger through high frequency and high efficiency, that is, the resonant conversion circuit LLC in the charger needs to achieve multi-phase current sharing while achieving a wide range of input or output.

[0003] However, currently, the LLC circuit in mobile phone chargers cannot achieve phase switching when achieving multi-phase current sharing and a wide range of input or output, resulting in low conversion efficiency of LLC under light load conditions. Summary of the Invention

[0004] To overcome the problems existing in the related art, the present disclosure provides a voltage switching circuit and method, a power adapter, and a storage medium, which can improve the flexibility of the voltage switching circuit, enhance the light load efficiency of the voltage switching circuit, reduce the light load loss, and thus better meet the sustainable development of energy consumption.

[0005] According to the first aspect of the embodiments of the present disclosure, a voltage switching circuit is provided, which at least includes:

[0006] An input end and an output end;

[0007] A plurality of resonant transformers, which are connected in parallel between the input end and the output end;

[0008] A switching circuit, one end of which is connected to the input end and the other end is connected to the plurality of resonant transformers;

[0009] Wherein, there are a plurality of first connection lines between the input end and the plurality of resonant transformers, and at least one of the plurality of first connection lines is conducting in different switching states of the switching circuit; and the number of the conducting first connection lines in different switching states is different.

[0010] In some embodiments, a plurality of second connection lines are formed between the plurality of resonant transformers and the output end;

[0011] The voltage switching circuit further includes:

[0012] A current sharing circuit, connected to at least one of the second connection lines, is configured to equalize the currents of the second connection lines connected to a plurality of target resonant transformers when a plurality of the first connection lines are conducting; wherein, the target resonant transformer is the resonant transformer connected to the conducting first connection line.

[0013] In some embodiments, the plurality of resonant transformers include: a first resonant transformer, a second resonant transformer, and a third resonant transformer;

[0014] The current sharing circuit includes: a first current sharing element and a second current sharing element;

[0015] The first current sharing element is connected in series to the second connection line connecting the second resonant transformer and the output terminal;

[0016] The second current sharing element is connected in series to the second connection line connecting the third resonant transformer and the output terminal.

[0017] In some embodiments, the voltage switching circuit further includes:

[0018] A first rectifying circuit, connected in series to the second connection line connecting the first resonant transformer and the output terminal;

[0019] A second rectifying circuit is arranged in series with the first current sharing element;

[0020] A third rectifying circuit is arranged in series with the second current sharing element.

[0021] In some embodiments, both the second rectifying circuit and the third rectifying circuit include a first rectifying diode and a second rectifying diode;

[0022] The first current sharing element is connected to the connection line between the first rectifying diode of the second rectifying circuit and the second rectifying diode of the second rectifying circuit;

[0023] The second current sharing element is connected to the connection line between the first rectifying diode of the third rectifying circuit and the second rectifying diode of the third rectifying circuit.

[0024] In some embodiments, both the first current sharing element and the second current sharing element include capacitors.

[0025] In some embodiments, when the first connection line connected to the first resonant transformer is conducting, the voltage switching circuit is in the first operating mode;

[0026] When all of the first connection lines connecting the first resonant transformer and the second resonant transformer are conducting, or when all of the first connection lines connecting the first resonant transformer and the third resonant transformer are conducting, the voltage switching circuit is in the second operating mode;

[0027] When all of the first connection lines connecting the first resonant transformer, the second resonant transformer, and the third resonant transformer are conducting, the voltage switching circuit is in the third operating mode;

[0028] Wherein, the gain of the voltage switching circuit in the first operating mode is less than the gain of the voltage switching circuit in the second operating mode, and the gain of the voltage switching circuit in the second operating mode is less than the gain of the voltage switching circuit in the third operating mode.

[0029] In some embodiments, the voltage switching circuit further includes: a plurality of voltage doubling capacitors; the voltage doubling capacitors are connected to each of the second connection lines;

[0030] The voltage doubling capacitor is configured to double the output voltage of the resonant transformer.

[0031] In some embodiments, the switching circuit includes a plurality of switching components; the switching components are connected to each of the first connection lines.

[0032] In some embodiments, the switching components connected to each of the first connection lines each include a first controlled switch and a second controlled switch;

[0033] The first controlled switch and the second controlled switch are connected in parallel between the input terminal and one of the resonant transformers.

[0034] In some embodiments, the voltage switching circuit further includes: a plurality of resonant components; the resonant components are connected to each of the first connection lines;

[0035] The resonant component is configured to filter the signal input to the resonant transformer.

[0036] According to a second aspect of the embodiments of the present disclosure, there is provided a power adapter, including at least:

[0037] The voltage switching circuit as described in the first aspect;

[0038] A detection module, connected to the output terminal of the voltage switching circuit, configured to detect the output voltage of the output terminal at the previous moment;

[0039] A control module, which is respectively connected to the detection module and the switch circuit of the voltage switching circuit, is configured to control the switch state of the switch circuit at the current moment based on the output voltage.

[0040] According to a third aspect of the embodiments of the present disclosure, a voltage switching method is provided, which at least includes:

[0041] Detect the output voltage of the output end of the voltage switching circuit in the power adapter at the previous moment;

[0042] When the output voltage meets a preset condition, control the switch state of the switch circuit in the voltage switching circuit at the current moment, so that at least one of the plurality of first connection lines between the input end of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is conducted.

[0043] In some embodiments, the plurality of resonant transformers include: a first resonant transformer, a second resonant transformer, and a third resonant transformer; when the output voltage meets a preset condition, controlling the switch state of the switch circuit in the voltage switching circuit at the current moment, so that at least one of the plurality of first connection lines between the input end of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is conducted, includes:

[0044] When the output voltage is less than the first voltage threshold, control the switch circuit to be in a first switch state, so that the first connection line connected to the first resonant transformer is conducted;

[0045] When the output voltage is greater than or equal to the first voltage threshold and less than the second voltage threshold, control the switch circuit to be in a second switch state, so that the first connection lines connected to the first resonant transformer and the second resonant transformer are both conducted, or control the first connection lines connected to the first resonant transformer and the third resonant transformer to be both conducted;

[0046] When the output voltage is greater than or equal to the second voltage threshold, control the switch circuit to be in a third switch state, so that the first connection lines connected to the first resonant transformer, the second resonant transformer, and the third resonant transformer are all conducted.

[0047] According to a fourth aspect of the embodiments of the present disclosure, a power adapter is provided, including:

[0048] A detection module, configured to detect the output voltage of the output end of the voltage switching circuit in the power adapter at the previous moment;

[0049] The control module is configured to control the switching state of the switching circuit in the voltage switching circuit at the current moment when the output voltage meets a preset condition, so that at least one of the plurality of first connection lines between the input end of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is turned on.

[0050] According to a fifth aspect of the embodiments of the present disclosure, there is provided a non-transitory computer-readable storage medium. When the instructions in the storage medium are executed by a processor of a power adapter, the power adapter can execute the voltage switching method as described in the third aspect.

[0051] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects:

[0052] The embodiments of the present disclosure provide a voltage switching circuit. The voltage switching circuit includes: an input end and an output end; a plurality of resonant transformers connected in parallel between the input end and the output end; a switching circuit with one end connected to the input end and the other end connected to the plurality of resonant transformers; wherein, there are a plurality of first connection lines between the input end and the plurality of resonant transformers, and at least one of the plurality of first connection lines is turned on when the switching circuit is in different switching states; and the number of the first connection lines turned on in different switching states is different. In this way, different from the LLC circuit in the related art that cannot achieve phase switching, the embodiments of the present disclosure can turn on at least one first connection line in the voltage switching circuit by the switching circuit in the voltage switching circuit being in different switching states, and the number of the first connection lines turned on in different switching states of the switching circuit is different each time, so that the number of the first connection lines turned on by the voltage switching circuit can be different by switching the switching state of the switching circuit in different scenarios, thereby improving the flexibility of the voltage switching circuit, enhancing the light load efficiency of the voltage switching circuit, reducing the light load loss, and further better meeting the sustainable development of energy consumption.

[0053] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.

[0055] Figure 1 is a schematic structural diagram of a traditional voltage switching circuit shown according to an exemplary embodiment Figure 1 .

[0056] Figure 2Schematic diagram of a traditional voltage switching circuit shown according to an exemplary embodiment Figure 2 .

[0057] Figure 3 Schematic diagram of a voltage switching circuit shown according to an exemplary embodiment Figure 1 .

[0058] Figure 4 Schematic diagram of an application scenario of a voltage switching circuit shown according to an exemplary embodiment.

[0059] Figure 5 Schematic diagram of a voltage switching circuit shown according to an exemplary embodiment Figure 2 .

[0060] Figure 6 Schematic diagram of a voltage switching circuit shown according to an exemplary embodiment Figure 3 .

[0061] Figure 7a Schematic diagram of a voltage switching circuit in the first working mode shown according to an exemplary embodiment.

[0062] Figure 7b Schematic diagram of a voltage switching circuit in the second working mode shown according to an exemplary embodiment.

[0063] Figure 7c Schematic diagram of a voltage switching circuit in the third working mode shown according to an exemplary embodiment.

[0064] Figure 8a Gain schematic diagram of a traditional first LLC circuit and second LLC circuit shown according to an exemplary embodiment.

[0065] Figure 8b Gain schematic diagram of a voltage switching circuit shown according to an exemplary embodiment.

[0066] Figure 9a Schematic diagram of the current waveform of a voltage switching circuit without a current sharing circuit set shown according to an exemplary embodiment.

[0067] Figure 9b Schematic diagram of the current waveform of a voltage switching circuit with a current sharing circuit set shown according to an exemplary embodiment.

[0068] Figure 10 Schematic diagram of the structure of a power adapter shown according to an exemplary embodiment.

[0069] Figure 11 Flow schematic diagram of a voltage switching method shown according to an exemplary embodiment.

[0070] Figure 12 It is a block diagram of a power adapter shown according to an exemplary embodiment. Detailed implementation manners

[0071] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present disclosure. On the contrary, they are merely examples of circuits and devices consistent with some aspects of the present disclosure as detailed in the appended claims.

[0072] The following will detail the technical solutions provided by the embodiments of the present disclosure in conjunction with the drawings.

[0073] In the related art, in order to achieve the purpose of high-power miniaturization of a power adapter such as a mobile phone charger, it is necessary to improve the power density of the charger through high-frequency and high-efficiency means, that is, the LLC circuit in the charger needs to achieve wide-range input or output while realizing multi-phase current sharing.

[0074] Exemplarily, as Figure 1 shown, if it is desired to achieve wide-range output on the LLC circuit in a mobile phone charger, such as an output voltage of 3.3 volts (V) to 21 V, a common method is to connect a step-down (Buck) circuit at the output of the LLC circuit. However, this method will cause an increase in volume as the power increases. Additionally, as Figure 2 shown, in a traditional multi-phase LLC current sharing circuit, each phase circuit is controlled separately to achieve the purpose of multi-phase current sharing. However, the control system of this circuit is complex, difficult to tune, and as the number of phases increases, Figure 2 the control chip and the auxiliary circuit in the dashed box also need to be increased. That is to say, the existing method of achieving wide-range output by cascading a buck circuit has problems of low efficiency and large volume, and the multi-phase parallel technology for achieving multi-phase current sharing has problems of complex control systems.

[0075] However, currently, when the LLC circuit in a mobile phone charger realizes multi-phase current sharing and wide-range input or output, phase switching cannot be achieved, resulting in low conversion efficiency of the LLC under light load conditions.

[0076] Based on this, the embodiments of the present disclosure propose a voltage switching circuit. Figure 3 It is a structural schematic of a voltage switching circuit shown according to an exemplary embodiment Figure 1 , as Figure 3 shown, the voltage switching circuit 10 provided by the embodiments of the present disclosure may include:

[0077] An input terminal 11 and an output terminal 12;

[0078] A plurality of resonant transformers Tr, which are arranged in parallel between the input terminal 11 and the output terminal 12;

[0079] A switching circuit 13, one end of which is connected to the input terminal 11 and the other end is connected to the plurality of resonant transformers Tr;

[0080] Wherein, there are a plurality of first connection lines 14 between the input terminal 11 and the plurality of resonant transformers Tr. In the case where the switching circuit 13 is in different switching states, at least one of the plurality of first connection lines 14 is conducting; and the number of the first connection lines 14 that are conducting in different switching states is different.

[0081] In the embodiments of the present disclosure, the above voltage switching circuit can be a circuit for converting voltage in a power adapter; for example, the above voltage switching circuit can be a boost circuit or a buck circuit, etc.

[0082] Exemplarily, as Figure 4 shown, a power adapter usually inputs through the power grid, that is, alternating current of 220V mains electricity, and then is converted into a direct current voltage after rectification and filtering. At this time, the converted direct current voltage will reach several hundred volts. If the power adapter is a charger for a mobile phone or household appliances, then multiple buck circuits need to be connected in parallel in the adapter to achieve the low voltage required for the mobile phone or household appliances; if the power adapter is a charger for an electric vehicle, then multiple boost circuits need to be connected in parallel in the adapter to achieve the high voltage required for the electric vehicle.

[0083] Here, the above input terminal can be a port for the above voltage switching circuit to receive an external power input electrical signal; the above output terminal can be a port for the power adapter where the above voltage switching circuit is located to charge an external device. For example, when the above voltage switching circuit is a circuit in a mobile phone charger, the above input terminal can be responsible for receiving alternating current from a socket, and the above output terminal can be responsible for outputting the direct current converted by the above voltage switching circuit to the mobile phone for charging.

[0084] In some embodiments, as Figure 3 shown, an input capacitor C can be connected in parallel at the above input terminal 11 in , and similarly, an output capacitor C can also be connected in parallel at the above output terminal 12 out ; the input capacitor C in and the output capacitor C out can both be used to store electrical energy to stabilize the input voltage and output voltage of the above voltage switching circuit.

[0085] The above-mentioned resonant transformer can be a component that changes the AC voltage by using the principle of electromagnetic induction. The main components of the above-mentioned resonant transformer may include a primary coil, a secondary coil, and an iron core (magnetic core). The above-mentioned resonant transformer has functions such as voltage conversion, current conversion, impedance conversion, isolation, or voltage stabilization.

[0086] It should be noted that the turns ratio of each of the above-mentioned resonant transformers among multiple above-mentioned resonant transformers can be the same or different, and can be set according to the actual application scenario, which is not limited in the embodiments of the present disclosure.

[0087] Among them, the turns ratio of the above-mentioned resonant transformer refers to the ratio between the number of turns of the primary-side winding coil and the number of turns of the secondary-side winding coil of the resonant transformer.

[0088] It can be understood that the ratio between the primary-side voltage and the secondary-side voltage of the above-mentioned resonant transformer is equal to this turns ratio. The embodiments of the present disclosure can realize the step-up and step-down conversion of voltage by reasonably selecting the turns ratio of the winding coils, that is, the turns ratio determines the voltage conversion ratio of the resonant transformer.

[0089] The above-mentioned switching circuit can be a circuit that enables the above-mentioned voltage switching circuit to connect to different above-mentioned resonant transformers; the above-mentioned first connection line can be a line connected between the above-mentioned input end and the above-mentioned resonant transformer. The switching circuit is connected to the above-mentioned first connection line and can conduct different numbers of first connection lines through different switch states.

[0090] It should be noted that the specific number of the above-mentioned first connection lines can be set according to the actual application scenario, as long as it is ensured that the number of the above-mentioned first connection lines is the same as the number of the above-mentioned resonant transformers, which is not limited in the embodiments of the present disclosure.

[0091] In some embodiments, as Figure 3 shown, the switching circuit 13 includes a plurality of switch components; each of the above-mentioned first connection lines 14 is connected with the switch component. In this way, the conduction of the first connection line can be controlled by controlling the switch states of the switch components on each first connection line, so that the voltage switching circuit conducts different first connection lines in different scenarios, thereby improving the flexibility of the voltage switching circuit.

[0092] It should be noted that the specific type of the above-mentioned switch component can be set according to the actual application scenario, which is not limited in the embodiments of the present disclosure. For example, the above-mentioned switch component can be a field effect transistor or a switch chip, etc.

[0093] In the embodiments of the present disclosure, the above-mentioned switching component can be various types of field-effect transistors, namely Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs), abbreviated as MOS transistors; for example, the above-mentioned switching component can be a PMOS transistor or an NMOS transistor.

[0094] It can be understood that when the above-mentioned switching component is a PMOS transistor, a low-level signal can be input to the gate of the PMOS transistor to control the PMOS transistor to be in the on state; or, a high-level signal can also be input to the gate of the PMOS transistor to control the PMOS transistor to be in the off state. When the above-mentioned field-effect transistor is an NMOS transistor, a high-level signal can be input to the gate of the NMOS transistor to make the NMOS transistor in the on state; or, a low-level signal can be input to the gate of the NMOS transistor to make the NMOS transistor in the off state.

[0095] It should be noted that the specific number of the above-mentioned switching components connected to each of the above-mentioned first connection lines can also be set according to the actual application scenario, and the embodiments of the present disclosure do not make any limitations. For example, the number of the above-mentioned switching components connected to each of the above-mentioned first connection lines can be one, two, three, etc.

[0096] In an embodiment of the present disclosure, as Figure 3 shown, each of the switching components connected to each of the first connection lines 14 includes a first controlled switch Q H and a second controlled switch Q L ;

[0097] The first controlled switch Q H and the second controlled switch Q L are connected in parallel between the input terminal 11 and one of the resonant transformers Tr.

[0098] Among them, both the above-mentioned first controlled switch and the above-mentioned second controlled switch can be MOS transistors; the switching types of the above-mentioned first controlled switch and the above-mentioned second controlled switch can be the same or different.

[0099] Here, when both the first controlled switch and the second controlled switch are PMOS transistors, a low-level signal is input to both the gate of the first controlled switch and the gate of the second controlled switch to turn on the first connection line connected to the first controlled switch and the second controlled switch; when both the first controlled switch and the second controlled switch are NMOS transistors, a high-level signal is input to both the gate of the first controlled switch and the gate of the second controlled switch to turn on the first connection line connected to the first controlled switch and the second controlled switch; when the first controlled switch is a PMOS transistor and the second controlled switch is an NMOS transistor, a low-level signal is input to the gate of the first controlled switch and a high-level signal is input to the gate of the second controlled switch to turn on the first connection line connected to the first controlled switch and the second controlled switch; when the first controlled switch is an NMOS transistor and the second controlled switch is a PMOS transistor, a high-level signal is input to the gate of the first controlled switch and a low-level signal is input to the gate of the second controlled switch to turn on the first connection line connected to the first controlled switch and the second controlled switch.

[0100] That is to say, by separately controlling the switching states of the first controlled switch and the second controlled switch on the first connection line, different numbers of the first connection lines can be turned on, so that the voltage switching circuit can more flexibly switch and connect different numbers of the first connection lines in different scenarios.

[0101] Exemplarily, as Figure 3 shown, three first connection lines 14 are formed between the input terminal 11 and the resonant transformer Tr; correspondingly, the first controlled switch Q H can include Q AH , Q BH and Q CH , and the second controlled switch Q L can include Q AL , Q BL and Q CL . Among them, Q AH and Q AL are connected in series with each other, Q BH and Q BL are connected in series with each other, Q CH and Q CL are connected in series with each other; and the first input port of each of the above-mentioned resonant transformers Tr is connected between the first controlled switch Q H and the second controlled switch Q L . Only when both the first controlled switch Q H and the second controlled switch Q L are in the on state, the first connection line 14 can be turned on, so that different working modes of the voltage switching circuit can be switched by turning on different first connection lines.

[0102] In some embodiments, such as Figure 3 shown, the voltage switching circuit 10 may further include: a plurality of resonant components 15; each of the first connection lines 14 is connected with the resonant component 15;

[0103] The resonant component 15 is configured to filter the signal input to the resonant transformer Tr.

[0104] In this way, by setting a plurality of resonant components, each first connection line is connected with a resonant component to filter the signal input to the resonant transformer, thereby ensuring the stability of the signal input to the resonant transformer.

[0105] Among them, the above-mentioned resonant components may include electronic components such as capacitive elements or inductive elements, and the above-mentioned resonant components may be connected in series between the above-mentioned switching circuit and the above-mentioned resonant transformer.

[0106] Exemplarily, as Figure 3 shown, three of the above-mentioned resonant components 15 may be connected to each of the above-mentioned first connection lines 14. The three above-mentioned resonant components 15 may include a capacitive element Cr and two inductive elements (Lkg and Lmg); the capacitive element Cr and an inductive element Lkg are connected in series between the above-mentioned switching circuit 13 and the first input port of the above-mentioned resonant transformer Tr in sequence, and the other inductive element Lmg is connected in parallel at the first input port and the second input port of the above-mentioned resonant transformer Tr, and is grounded at the second input port of the above-mentioned resonant transformer Tr.

[0107] It should be noted that the specific number of the above-mentioned resonant components can be set according to the actual application scenario, and the embodiments of the present disclosure do not make any limitations.

[0108] Embodiments of the present disclosure provide a voltage switching circuit, which includes: an input end and an output end; a plurality of resonant transformers, which are connected in parallel between the input end and the output end; a switching circuit, one end of which is connected to the input end and the other end is connected to the plurality of resonant transformers; wherein, there are a plurality of first connection lines between the input end and the plurality of resonant transformers, and at least one of the plurality of first connection lines is conducted in different switching states of the switching circuit; and the number of the first connection lines conducted in different switching states is different. Thus, different from the LLC circuit in the related art that cannot achieve phase switching, embodiments of the present disclosure can conduct at least one first connection line in the voltage switching circuit by the switching circuit in different switching states, and the number of the first connection lines conducted in different switching states of the switching circuit is different each time, so as to make the number of the first connection lines conducted in the voltage switching circuit different by switching the switching state of the switching circuit in different scenarios, thereby improving the flexibility of the voltage switching circuit, enhancing the light load efficiency of the voltage switching circuit, reducing the light load loss, and further meeting the sustainable development of energy consumption more.

[0109] Figure 5 is a schematic structural diagram of a voltage switching circuit shown according to an exemplary embodiment Figure 2 , such as Figure 5 shown, the voltage switching circuit provided by the embodiments of the present disclosure further adds other components on the basis of the Figure 3 voltage switching circuit shown, for example, a current sharing circuit.

[0110] Such as Figure 5 shown, a plurality of second connection lines 16 are formed between the plurality of resonant transformers Tr and the output end 12; the voltage switching circuit 10 provided by the embodiments of the present disclosure may further include:

[0111] A current sharing circuit 17, which is connected to at least one of the second connection lines 16 and is configured to equalize the currents of the plurality of second connection lines 16 connected to a plurality of target resonant transformers when the plurality of first connection lines 14 are conducted; wherein, the target resonant transformer is the resonant transformer Tr connected to the conducted first connection line 14.

[0112] Thus, by providing a current sharing circuit on at least one second connection line, automatic current sharing can be achieved on the second connection line connected to the resonant transformer connected to the first connection line when the plurality of first connection lines are conducted, thereby improving the output power of the voltage switching circuit.

[0113] Among them, the second connection line can be a line connected between the resonant transformer and the output terminal; the current sharing circuit can be a circuit that realizes automatic current sharing of multiple second connection lines.

[0114] It should be noted that the specific number of the second connection lines can be set according to the actual application scenario, as long as the number of the second connection lines is the same as the number of the resonant transformers, which is not limited in the embodiments of the present disclosure.

[0115] It can be understood that the current sharing circuit can include multiple current sharing elements, and the number of the current sharing elements can be set according to the number of the resonant transformers; that is, when the number of the resonant transformers is N, the number of the current sharing elements in the current sharing circuit can be N - 1, and N is an integer greater than 1.

[0116] In an embodiment of the present disclosure, as Figure 5 shown, multiple resonant transformers Tr include: a first resonant transformer TrA, a second resonant transformer TrB, and a third resonant transformer TrC;

[0117] The current sharing circuit 17 includes: a first current sharing element C1 and a second current sharing element C2;

[0118] The first current sharing element C1 is connected in series on the second connection line 16 connecting the second resonant transformer TrB and the output terminal 12;

[0119] The second current sharing element C2 is connected in series on the second connection line 16 connecting the third resonant transformer TrC and the output terminal 12.

[0120] In this way, by setting the first current sharing element on the second connection line connecting the second resonant transformer and the output terminal, and setting the second current sharing element on the second connection line connecting the third resonant transformer and the output terminal, automatic current sharing can be realized when the first resonant transformer and the second resonant transformer are both turned on, or when the first resonant transformer, the second resonant transformer, and the third resonant transformer are all turned on, so as to improve the output power of the voltage switching circuit.

[0121] Among them, the turns ratios of the first resonant transformer, the second resonant transformer, and the third resonant transformer can be the same or different; for example, the turns ratio of the first resonant transformer can be N A : 1, the turns ratio of the first resonant transformer can be N B : 1, the turns ratio of the first resonant transformer can be N C : 1.

[0122] In the embodiments of the present disclosure, both the first current-sharing element and the second current-sharing element include capacitors.

[0123] Here, both the first current-sharing element and the second current-sharing element can be flying capacitors; a flying capacitor is a high-voltage capacitor, which can operate under high voltage and has a larger capacitance, that is, energy storage capacity, compared with ordinary capacitors.

[0124] It should be noted that the specific types of the first current-sharing element and the second current-sharing element can be set according to the actual application scenario, and the embodiments of the present disclosure do not make any limitations.

[0125] In some embodiments, as Figure 5 shown, the voltage switching circuit 10 may further include:

[0126] A first rectifying circuit, connected in series on the second connection line 16 connecting the first resonant transformer TrA and the output terminal 12;

[0127] A second rectifying circuit, connected in series with the first current-sharing element C1;

[0128] A third rectifying circuit, connected in series with the second current-sharing element C2.

[0129] In this way, by respectively arranging the first rectifying circuit, the second rectifying circuit and the third rectifying circuit on each second connection line connected to the resonant transformer, the alternating current output by the resonant transformer can be converted into direct current, so that the signal output by the voltage switching circuit can be used by external devices.

[0130] Among them, the first rectifying circuit can be a circuit for rectifying the signal output by the first resonant transformer; the second rectifying circuit can be a circuit for rectifying the signal output by the second resonant transformer; the third rectifying circuit can be a circuit for rectifying the signal output by the third resonant transformer.

[0131] It can be understood that the number of rectifying circuits provided in the above voltage switching circuit needs to be the same as the number of resonant transformers, and the second rectifying circuit connected to the second resonant transformer can be connected in series with the first current-sharing element, and the third rectifying circuit connected to the third resonant transformer can be connected in series with the second current-sharing element, so as to ensure that when multiple resonant transformers are turned on, automatic current sharing can be realized on the second connection line connected to the resonant transformer, thereby improving the output power of the voltage switching circuit.

[0132] It should be noted that the specific number of rectifying diodes in the above-mentioned first rectifying circuit, the second rectifying circuit, and the third rectifying circuit can all be set according to the actual application scenario, and the embodiments of the present disclosure do not make any limitations.

[0133] In an embodiment of the present disclosure, as Figure 5 shown, both the second rectifying circuit and the third rectifying circuit include a first rectifying diode and a second rectifying diode;

[0134] The first current-sharing element C1 is connected to the connection line between the first rectifying diode D BH of the second rectifying circuit and the second rectifying diode D BL of the second rectifying circuit;

[0135] The second current-sharing element C2 is connected to the connection line between the first rectifying diode D CH of the third rectifying circuit and the second rectifying diode D CL of the third rectifying circuit.

[0136] In this way, by setting the first current-sharing element on the connection line between the first rectifying diode of the second rectifying circuit and the second rectifying diode of the second rectifying circuit, and setting the second current-sharing element on the connection line between the first rectifying diode of the third rectifying circuit and the second rectifying diode of the third rectifying circuit, it is possible to better achieve automatic current sharing on the second connection line connected to the resonant transformer when different resonant transformers in the voltage switching circuit are working, thereby improving the output power and light load efficiency of the voltage switching circuit.

[0137] Among them, the first rectifying diode or the second rectifying diode of the second rectifying circuit, and the first rectifying diode or the second rectifying diode of the third rectifying circuit can both be diodes capable of converting alternating current into direct current. The diode can include a PN junction and has two terminals, a positive terminal and a negative terminal; the diode has unidirectional conductivity, and in the circuit, the current can only flow into the diode from the positive terminal and flow out from the negative terminal.

[0138] Here, the above output terminal may include a first pin and a second pin; the first rectifier diode of the second rectifier circuit and the first rectifier diode of the third rectifier circuit may be connected in series between the first current-sharing element and the first pin in sequence; the second output port of the first resonant transformer, the second output port of the second resonant transformer, the second output port of the third resonant transformer, the second rectifier diode of the second rectifier circuit, and the second rectifier diode of the third rectifier circuit are all connected to the second pin; the first current-sharing element is connected to one end of the second rectifier diode of the second rectifier circuit and may also be connected to the first output port of the second resonant transformer; the second current-sharing element is connected to one end of the second rectifier diode of the third rectifier circuit and may also be connected to the first output port of the third resonant transformer.

[0139] In the embodiments of the present disclosure, the first rectifier circuit may also include a first rectifier diode and a second rectifier diode; the first rectifier diode of the first rectifier circuit may be connected between the first output port of the first resonant transformer and the first rectifier diode of the second rectifier circuit, one end of the second rectifier diode of the first rectifier circuit may be connected between the first output port of the first resonant transformer and the first rectifier diode of the first rectifier circuit, and one end of the second rectifier diode of the first rectifier circuit may be connected to the second output port of the first resonant transformer.

[0140] In some embodiments, as Figure 5 shown, the voltage switching circuit 10 may further include: a plurality of voltage doubling capacitors Cd; the voltage doubling capacitors Cd are connected to each of the second connection lines 16;

[0141] The voltage doubling capacitor Cd is configured to double the output voltage of the resonant transformer Tr.

[0142] In this way, by setting voltage doubling capacitors on each second connection line, the output voltage of the resonant transformer can be doubled in different scenarios, thereby improving the output power of the voltage switching circuit.

[0143] Among them, the above voltage doubling capacitor may be a capacitor element capable of doubling the output voltage of the above resonant transformer.

[0144] It can be understood that by using the rectifying and guiding effect of the rectifier diodes in the above rectifier circuit, the voltage doubling capacitors are charged and discharged, and the voltages of the voltage doubling capacitors are superimposed on each other to double the output voltage of the above resonant transformer.

[0145] Here, multiple of the above-mentioned voltage doubling capacitors may include: a first voltage doubling capacitor, a second voltage doubling capacitor, and a third voltage doubling capacitor; the first voltage doubling capacitor may be connected between the first output port of the first resonant transformer and the first rectifying tube of the first rectifying circuit; the second voltage doubling capacitor may be connected between the first output port of the second resonant transformer and the first current sharing element; the third voltage doubling capacitor may be connected between the first output port of the third resonant transformer and the second current sharing element.

[0146] Exemplarily, as Figure 6 shown, the first voltage doubling capacitor C dA , the first rectifying tube D AH of the first rectifying circuit, the first rectifying tube D BH of the second rectifying circuit, and the first rectifying tube D CH of the third rectifying circuit are connected in series in sequence between the first output port a1 of the first resonant transformer TrA and the first pin 121 of the output terminal 12; the second rectifying tube D AL of the first rectifying circuit has one end connected between the first voltage doubling capacitor C dA and the first rectifying tube D AH of the first rectifying circuit, and the other end connected between the second output port a2 of the first resonant transformer TrA and the second pin 122 of the output terminal 12; the second voltage doubling capacitor C dB and the second rectifying tube D BL of the second rectifying circuit are connected in series in sequence between the first output port b1 of the second resonant transformer TrB and the second pin 122 of the output terminal 12; the third voltage doubling capacitor C dC and the second rectifying tube D CL of the third rectifying circuit are connected in series in sequence between the first output port c1 of the third resonant transformer TrC and the second pin 122 of the output terminal 12; the above-mentioned first current sharing element C1 has one end connected between the first rectifying tube D AH of the first rectifying circuit and the first rectifying tube D BH of the second rectifying circuit, and the other end connected between the second voltage doubling capacitor C dB and the second rectifying tube D BL of the second rectifying circuit; the above-mentioned second current sharing element C2 has one end connected between the first rectifying tube D BH of the second rectifying circuit and the first rectifying tube D CH of the third rectifying circuit, and the other end connected between the third voltage doubling capacitor C dC and the second rectifying tube D CL of the third rectifying circuit; and the second output port a2 of the first resonant transformer TrA, the second output port b2 of the second resonant transformer TrB, and the second output port c2 of the third resonant transformer TrC are all connected to the second pin 122 of the output terminal 12.

[0147] In some embodiments, when the first connection line connected to the first resonant transformer is conducting, the voltage switching circuit is in the first operating mode;

[0148] When both the first connection lines connected to the first resonant transformer and the second resonant transformer are conducting, or when both the first connection lines connected to the first resonant transformer and the third resonant transformer are conducting, the voltage switching circuit is in the second operating mode;

[0149] When all the first connection lines connected to the first resonant transformer, the second resonant transformer, and the third resonant transformer are conducting, the voltage switching circuit is in the third operating mode;

[0150] Among them, the gain of the voltage switching circuit in the first operating mode is less than the gain of the voltage switching circuit in the second operating mode, and the gain of the voltage switching circuit in the second operating mode is less than the gain of the voltage switching circuit in the third operating mode.

[0151] In this way, by conducting the first connection lines connected to different resonant transformers, the voltage switching circuit can be in different operating modes, thereby improving the flexibility of the voltage switching circuit, enhancing the light-load efficiency of the voltage switching circuit, reducing the light-load loss, and further better meeting the sustainable development of energy consumption.

[0152] Here, the above-mentioned first operating mode can be the single-phase operating mode of the above-mentioned voltage switching circuit; the above-mentioned second operating mode can be the two-phase operating mode of the above-mentioned voltage switching circuit; the above-mentioned third operating mode can be the three-phase operating mode of the above-mentioned voltage switching circuit.

[0153] It can be understood that when the above-mentioned voltage switching circuit is in the first operating mode, that is, the single-phase operating mode, as Figure 7a shown, the switching components Q AH and Q AL connected to the above-mentioned first resonant transformer TrA are conducting with each other, and the switching components Q BH and Q BL connected to the above-mentioned second resonant transformer TrB and the switching components Q CH and Q CL connected to the above-mentioned third resonant transformer TrC are all in the cut-off state; at this time, only the first connection line and the second connection line connected to the first resonant transformer TrA, that is, phase A, are working, and the output voltage of the above-mentioned output terminal 12 can be twice the output voltage of the first resonant transformer TrA. The gain function of the above-mentioned voltage switching circuit in the single-phase operating mode can be formula (1):

[0154]

[0155] When the above voltage switching circuit is in the second operating mode, i.e., the bipolar operating mode, as Figure 7b shown, the switching components Q AH and Q AL connected to the first resonant transformer TrA and the switching components Q BH and Q BL connected to the second resonant transformer TrB are all conducting with each other, and the switching components Q CH and Q CL connected to the third resonant transformer TrC are in the cut-off state. At this time, phase A and the first connection line and the second connection line connected to the second resonant transformer TrB, i.e., phase B, are both operating; due to the presence of the first current-sharing element C1, the currents of phase A and phase B can achieve automatic current sharing. In the bipolar operating mode, the output voltage of the above output terminal 12 can be four times the output voltages of the two resonant transformers, i.e., the first resonant transformer TrA and the second resonant transformer TrB. At this time, the gain function of the above voltage switching circuit in the bipolar operating mode can be the formula (2):

[0156]

[0157] When the above voltage switching circuit is in the third operating mode, i.e., the three-phase operating mode, as Figure 7c shown, the switching components Q AH and Q AL connected to the first resonant transformer TrA, the switching components Q BH and Q BL connected to the second resonant transformer TrB, and the switching components Q CH and Q CL connected to the third resonant transformer TrC are all conducting with each other. At this time, phase A, phase B, and phase C are all operating; due to the presence of the first current-sharing element C1 and the second current-sharing element C2, the currents of phase A, phase B, and phase C can all achieve automatic current sharing. In the three-phase operating mode, the output voltage of the above output terminal 12 can be six times the output voltages of the three resonant transformers, i.e., the first resonant transformer TrA, the second resonant transformer TrB, and the third resonant transformer TrC. At this time, the gain function of the above voltage switching circuit in the three-phase operating mode can be the formula (3):

[0158]

[0159] wherein, V out is the output voltage of the output terminal of the above voltage switching circuit, V inis the input voltage at the input terminal of the above voltage switching circuit, N is the turns ratio of the resonant transformer, A is the ratio of the inductance elements in the resonant components connected to the resonant transformer (such as L kgA / L mgA ), f r is the frequency of the switching components connected to the resonant transformer, f s is the resonant frequency of the resonant components, and Q L is the parameter of the equivalent circuit of the resonant components.

[0160] In the embodiments of the present disclosure, when the output voltage at the output terminal of the above voltage switching circuit is less than a preset first voltage threshold, the above voltage switching circuit is in the first working mode; when the output voltage at the output terminal of the above voltage switching circuit is greater than or equal to the first voltage threshold and less than a preset second voltage threshold, the above voltage switching circuit can switch from the first working mode to the second working mode; when the output voltage at the output terminal of the above voltage switching circuit is greater than or equal to the second voltage threshold, the above voltage switching circuit can switch from the second working mode to the third working mode. That is to say, the embodiments of the present disclosure can control the conduction of different numbers of first connection lines in different load scenarios to switch different working modes, thereby improving the flexibility of the voltage switching circuit, enhancing the light load efficiency of the voltage switching circuit, reducing the light load loss, and further meeting the sustainable development of energy consumption.

[0161] As Figure 8a shown, the dotted curve represents the traditional first LLC circuit, and the solid curve is the traditional second LLC circuit; it can be seen from Figure 8a that the first LLC circuit cannot achieve a wide range of voltage outputs, and the second LLC circuit can meet the wide output range of 5 to 28V in the fast charging protocol, but can only ensure a wide range of outputs within the working frequency range of about 0.48 to 1.1. Figure 8b Shown is the gain characteristic curve of the voltage switching circuit proposed by the present disclosure. As Figure 8b shown, a wide range of outputs can also be achieved through the switching of single-phase, two-phase, and three-phase. Under light load conditions, the above voltage switching circuit can be in the single-phase working mode; as the load increases, the above voltage switching circuit can switch to the two-phase or even three-phase working mode to improve the efficiency of the power adapter; and through the switching of the working mode, the frequency conversion range can be reduced to the range of 0.7 to 1, improving the efficiency of the voltage switching circuit and reducing the light load loss.

[0162] In addition, Figure 9a shown are the current waveforms of phases A, B, and C in the voltage switching circuit when the current sharing circuit is not set, Figure 9b shown are the current waveforms of phases A, B, and C in the voltage switching circuit when the current sharing circuit is set. It can be seen fromFigure 9a It can be seen that in a voltage switching circuit without a current sharing circuit, due to the differences in the parameters of the components in the voltage switching circuit, the current in the voltage switching circuit will be concentrated in one of the phases, causing a huge current stress on this phase. Over time, it will damage the lifespan of the power adapter where the voltage switching circuit is located; while as Figure 9b shown, the voltage switching circuit provided in this disclosure with a current sharing circuit can balance and evenly distribute the three-phase current, achieving the purpose of automatic current sharing.

[0163] Figure 10 is a schematic structural diagram of a power adapter shown according to an exemplary embodiment. As Figure 10 shown, an embodiment of this disclosure provides a power adapter 1, which may include:

[0164] the voltage switching circuit 10 described in the above embodiment of this disclosure;

[0165] a detection module 101, connected to the output terminal 12 of the voltage switching circuit 10, and configured to detect the output voltage of the output terminal 12 at the previous moment;

[0166] a control module 102, respectively connected to the detection module 101 and the switch circuit 13 of the voltage switching circuit 10, and configured to control the switch state of the switch circuit 13 at the current moment based on the output voltage.

[0167] In the embodiment of this disclosure, the above power adapter may be a device that converts alternating current into direct current; for example, the above power adapter may be a charger for devices such as electric vehicles, household appliances, or mobile phones.

[0168] Among them, the above detection module may be a module for detecting the output voltage of the output terminal of the above voltage switching circuit. The above control module may be a module for controlling the switch state of the switch circuit in the voltage switching circuit; for example, the above control module may be a microcontroller unit (MCU) in the above power adapter.

[0169] It can be understood that the detection module in the power adapter detects the output voltage of the output terminal of the voltage switching circuit at the previous moment and sends the output voltage to the control module. The control module can control the switch state of the switch circuit at the current moment by determining whether the output voltage meets the preset conditions, so as to be able to switch different working modes by controlling different switch states of the switch circuit under different load scenarios.

[0170] Figure 11 is a schematic flowchart of a voltage switching method shown according to an exemplary embodiment. As Figure 11As shown, the voltage switching method provided by the embodiments of the present disclosure is applied to a power adapter and may at least include the following steps:

[0171] Step 1110: Detect the output voltage at the output end of the voltage switching circuit in the power adapter at the previous moment.

[0172] Step 1120: When the output voltage meets the preset conditions, control the switching state of the switching circuit in the voltage switching circuit at the current moment, so that at least one of the plurality of first connection lines between the input end of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is turned on.

[0173] In step 1110, the above output voltage can be detected by a detection module in the above power adapter.

[0174] Here, after detecting the above output voltage, the switching state of the switching circuit in the voltage switching circuit at the current moment can be controlled based on the output voltage, so as to be able to switch different working modes under different load scenarios in the subsequent process.

[0175] In step 1120, the above output voltage meeting the preset conditions may include: the above output voltage is less than the first voltage threshold; or, the above output voltage is greater than or equal to the first voltage threshold and less than the second voltage threshold; or, the above output voltage is greater than or equal to the second voltage threshold.

[0176] In an embodiment of the present disclosure, the plurality of resonant transformers include: a first resonant transformer, a second resonant transformer, and a third resonant transformer; step 1120 may specifically include:

[0177] When the output voltage is less than the first voltage threshold, control the switching circuit to be in the first switching state, so that the first connection line connected to the first resonant transformer is turned on.

[0178] When the output voltage is greater than or equal to the first voltage threshold and less than the second voltage threshold, control the switching circuit to be in the second switching state, so that the first connection lines connected to the first resonant transformer and the second resonant transformer are both turned on, or control the first connection lines connected to the first resonant transformer and the third resonant transformer to be both turned on.

[0179] When the output voltage is greater than or equal to the second voltage threshold, control the switching circuit to be in the third switching state, so that the first connection lines connected to the first resonant transformer, the second resonant transformer, and the third resonant transformer are all turned on.

[0180] In this way, the switching state of the switching circuit can be determined by comparing the detected output voltage with the first voltage threshold and the second voltage threshold, so that the first connection line connecting different resonant transformers is turned on, thereby improving the flexibility of the voltage switching circuit, enhancing the light-load efficiency of the voltage switching circuit, reducing the light-load loss, and further better meeting the sustainable development of energy consumption.

[0181] Among them, the switching circuit being in the first switching state may include: the switching components connected to the first resonant transformer are all turned on, and the switching components connected to the second resonant transformer and the third resonant transformer are all turned off. The switching circuit being in the second switching state may include: the switching components connected to the first resonant transformer and the second resonant transformer are all turned on, and the switching components connected to the third resonant transformer are all turned off; or, the switching components connected to the first resonant transformer and the third resonant transformer are all turned on, and the switching components connected to the second resonant transformer are all turned off. The switching circuit being in the third switching state may include: the switching components connected to the first resonant transformer, the second resonant transformer, and the third resonant transformer are all turned on.

[0182] In the embodiment of the present disclosure, when the switching circuit is in the first switching state, the voltage switching circuit may be in the first working mode; when the switching circuit is in the second switching state, the voltage switching circuit may be in the second working mode; when the switching circuit is in the third switching state, the voltage switching circuit may be in the third working mode.

[0183] The voltage switching method provided by the embodiment of the present disclosure can compare the output voltage at the output end of the detected voltage switching circuit with the first voltage threshold and the second voltage threshold to determine the switching state of the switching circuit in the voltage switching circuit, so that at least one first connection line is turned on, and the number of first connection lines turned on in different switching states of the switching circuit is different each time. Thus, the number of first connection lines turned on by the voltage switching circuit can be made different by controlling different switching states of the switching circuit in different load scenarios, so as to improve the flexibility of the voltage switching circuit, enhance the light-load efficiency of the voltage switching circuit, reduce the light-load loss, and further better meet the sustainable development of energy consumption.

[0184] Figure 12 This is a structural block diagram of a power adapter provided by an embodiment of the present disclosure. Refer to Figure 12 , the power adapter 1 provided by the embodiment of the present disclosure may include: a detection module 101 and a control module 102.

[0185] Among them, the detection module 101 is configured to detect the output voltage at the output end of the voltage switching circuit in the power adapter at the previous moment;

[0186] The control module 102 is configured to control the switching state of the switching circuit in the voltage switching circuit at the current moment when the output voltage meets a preset condition, so that at least one of the plurality of first connection lines between the input end of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is turned on.

[0187] The power adapter provided by the embodiment of the present disclosure can determine the switching state of the switching circuit in the voltage switching circuit by detecting the output voltage at the output end of the voltage switching circuit, so that at least one first connection line is turned on, and the number of the first connection lines turned on in different switching states of the switching circuit is different each time. Therefore, the number of the first connection lines turned on by the voltage switching circuit can be different by controlling different switching states of the switching circuit in different load scenarios, so as to improve the flexibility of the voltage switching circuit, improve the light load efficiency of the voltage switching circuit, reduce the light load loss, and further better meet the sustainable development of energy consumption.

[0188] For Figure 12 In a possible implementation manner of the technical solution shown, the plurality of resonant transformers include: a first resonant transformer, a second resonant transformer, and a third resonant transformer; the control module 102 may specifically be configured to: when the output voltage is less than a first voltage threshold, control the switching circuit to be in a first switching state, so that the first connection line connected to the first resonant transformer is turned on; when the output voltage is greater than or equal to the first voltage threshold and less than a second voltage threshold, control the switching circuit to be in a second switching state, so that the first connection lines connected to the first resonant transformer and the second resonant transformer are both turned on, or control the first connection lines connected to the first resonant transformer and the third resonant transformer to be both turned on; when the output voltage is greater than or equal to the second voltage threshold, control the switching circuit to be in a third switching state, so that the first connection lines connected to the first resonant transformer, the second resonant transformer, and the third resonant transformer are all turned on.

[0189] It should be noted that the power adapter provided by the embodiment of the present disclosure corresponds to the voltage switching method mentioned above. For related content, reference may be made to the description of the voltage switching method above, and details are not described herein again.

[0190] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is further provided, such as a memory including instructions, and the above instructions can be executed by a processor of a power adapter. For example, the non-transitory computer-readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0191] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising said element.

[0192] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include known common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and examples are only to be considered as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0193] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A voltage switching circuit, characterized in that, Comprising: An input terminal and an output terminal; A plurality of resonant transformers, arranged in parallel between the input terminal and the output terminal; A switching circuit, one end connected to the input terminal and the other end connected to the plurality of resonant transformers; Wherein, there are a plurality of first connection lines between the input terminal and the plurality of resonant transformers, and at least one of the plurality of first connection lines is conducting when the switching circuit is in different switching states; And the number of the first connection lines conducting in different switching states is different.

2. The voltage switching circuit according to claim 1, characterized in that, A plurality of second connection lines are formed between the plurality of resonant transformers and the output terminal; The voltage switching circuit further comprises: A current sharing circuit, connected to at least one of the second connection lines, configured to share the current of the plurality of second connection lines connected to a plurality of target resonant transformers when the plurality of first connection lines are conducting; wherein, the target resonant transformer is the resonant transformer connected to the conducting first connection line.

3. The voltage switching circuit according to claim 2, characterized in that, The plurality of resonant transformers include: a first resonant transformer, a second resonant transformer and a third resonant transformer; The current sharing circuit comprises: a first current sharing element and a second current sharing element; The first current sharing element is connected in series to the second connection line connecting the second resonant transformer and the output terminal; The second current sharing element is connected in series to the second connection line connecting the third resonant transformer and the output terminal.

4. The voltage switching circuit according to claim 3, characterized in that, The voltage switching circuit further comprises: A first rectifying circuit, connected in series to the second connection line connecting the first resonant transformer and the output terminal; A second rectifying circuit, arranged in series with the first current sharing element; A third rectifying circuit, arranged in series with the second current sharing element.

5. The voltage switching circuit according to claim 4, characterized in that, Both the second rectifying circuit and the third rectifying circuit include a first rectifying diode and a second rectifying diode; The first current sharing element is connected to the connection line between the first rectifying diode of the second rectifying circuit and the second rectifying diode of the second rectifying circuit; The second current sharing element is connected to the connection line between the first rectifying diode of the third rectifying circuit and the second rectifying diode of the third rectifying circuit.

6. The voltage switching circuit according to claim 3, characterized in that, Both the first current sharing element and the second current sharing element include a capacitor.

7. The voltage switching circuit according to claim 3, characterized in that, When the first connection line connecting the first resonant transformer is conducting, the voltage switching circuit is in a first operating mode; When the first connection lines connecting the first resonant transformer and the second resonant transformer are both conducting, or when the first connection lines connecting the first resonant transformer and the third resonant transformer are both conducting, the voltage switching circuit is in a second operating mode; When the first connection lines connecting the first resonant transformer, the second resonant transformer and the third resonant transformer are all conducting, the voltage switching circuit is in a third operating mode; Wherein, the gain of the voltage switching circuit in the first operating mode is less than the gain of the voltage switching circuit in the second operating mode, and the gain of the voltage switching circuit in the second operating mode is less than the gain of the voltage switching circuit in the third operating mode.

8. The voltage switching circuit according to claim 2, characterized in that, The voltage switching circuit further includes: a plurality of voltage doubling capacitors; each of the second connection lines is connected with the voltage doubling capacitor; The voltage doubling capacitor is configured to double the output voltage of the resonant transformer.

9. The voltage switching circuit according to any one of claims 1 to 8, characterized in that, The switching circuit includes a plurality of switching components; each of the first connection lines is connected with the switching component.

10. The voltage switching circuit according to claim 9, characterized in that, Each of the switching components connected to each of the first connection lines includes a first controlled switch and a second controlled switch; The first controlled switch and the second controlled switch are connected in parallel between the input terminal and one of the resonant transformers.

11. The voltage switching circuit according to any one of claims 1 to 8, wherein, The voltage switching circuit further includes: a plurality of resonant components; each of the first connection lines is connected with the resonant component; The resonant component is configured to filter the signal input to the resonant transformer.

12. A power adapter, wherein, Comprising: The voltage switching circuit according to any one of claims 1 to 11; A detection module, connected to the output terminal of the voltage switching circuit, and configured to detect the output voltage of the output terminal at the previous moment; A control module, respectively connected to the detection module and the switching circuit of the voltage switching circuit, and configured to control the switching state of the switching circuit at the current moment based on the output voltage.

13. A voltage switching method, wherein, Comprising: Detecting the output voltage of the output terminal of the voltage switching circuit in the power adapter at the previous moment; When the output voltage meets a preset condition, controlling the switching state of the switching circuit in the voltage switching circuit at the current moment, so that at least one of the plurality of first connection lines between the input terminal of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is turned on.

14. The voltage switching method according to claim 13, wherein, The plurality of resonant transformers include: a first resonant transformer, a second resonant transformer, and a third resonant transformer; when the output voltage meets a preset condition, controlling the switching state of the switching circuit in the voltage switching circuit at the current moment, so that at least one of the plurality of first connection lines between the input terminal of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is turned on, includes: When the output voltage is less than a first voltage threshold, controlling the switching circuit to be in a first switching state, so that the first connection line connected to the first resonant transformer is turned on; When the output voltage is greater than or equal to the first voltage threshold and less than a second voltage threshold, controlling the switching circuit to be in a second switching state, so that the first connection lines connected to the first resonant transformer and the second resonant transformer are both turned on, or controlling the first connection lines connected to the first resonant transformer and the third resonant transformer to be both turned on; When the output voltage is greater than or equal to the second voltage threshold, control the switching circuit to be in the third switching state, so that all the first connection lines connected to the first resonant transformer, the second resonant transformer and the third resonant transformer are turned on.

15. A power adapter, wherein, Comprising: A detection module configured to detect the output voltage of the output terminal of the voltage switching circuit in the power adapter at the previous moment; A control module configured to control the switching state of the switching circuit in the voltage switching circuit at the current moment when the output voltage meets a preset condition, so that at least one of the plurality of first connection lines between the input terminal of the voltage switching circuit and the plurality of resonant transformers of the voltage switching circuit is turned on.

16. A non-transitory computer-readable storage medium, wherein, When the instruction in the storage medium is executed by the processor of the power adapter, the power adapter can execute the voltage switching method according to any one of claims 13 or 14.

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