CN115189585A

CN115189585A - Power supply circuit, circuit control method, power supply device, and electronic apparatus

Info

Publication number: CN115189585A
Application number: CN202210690121.8A
Authority: CN
Inventors: 郭红光; 张晨松; 李建国; 张锦; 纪策; 田晨; 张加亮
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2022-06-17
Filing date: 2022-06-17
Publication date: 2022-10-14
Also published as: WO2023240990A1

Abstract

The application relates to the power supply circuit, the circuit control method, the power supply device and the electronic equipment, wherein the charging and discharging circuit is connected between the rectifying circuit and the converting circuit in parallel, and the working mode of the charging and discharging circuit is controlled by the control circuit according to the output power of the rectifying circuit and the input power of the converting circuit, so that energy can flow into the charging and discharging circuit when the energy needs to be stored, and energy can flow out of the charging and discharging circuit when the energy needs to be released. It can be seen that, only a small part of energy in the power supply circuit provided by the embodiment of the application can pass through the charging and discharging circuit, and compared with a PFC circuit in the prior art, the energy storage capacity requirement of the charging and discharging circuit provided by the embodiment of the application is smaller, so that the volume of the energy storage circuit in the charging and discharging circuit is smaller, and the volume of the power supply circuit can be reduced.

Description

Power supply circuit, circuit control method, power supply device, and electronic apparatus

Technical Field

The present disclosure relates to circuit technologies, and in particular, to a power supply circuit, a circuit control method, a power supply device, and an electronic apparatus.

Background

With the development of circuit technology, the structure and function of the power supply circuit are more and more perfect.

In general, the output Power of the rectifying circuit in the Power supply circuit is time-varying, but the input Power of the inverter circuit in the Power supply circuit is generally relatively constant, and therefore, a Power Factor Correction (PFC) circuit is provided in series between the rectifying circuit and the inverter circuit to store and release energy.

However, the size of the memory cell in the PFC circuit is large, resulting in a large power supply circuit.

Disclosure of Invention

In view of the above, it is desirable to provide a power supply circuit, a circuit control method, a power supply device, and an electronic apparatus, which can reduce the size of the power supply circuit.

In a first aspect, the present application provides a power supply circuit comprising: the charging and discharging circuit is connected with the rectifying circuit and the converting circuit in parallel respectively, and the control circuit is connected with the charging and discharging circuit;

the rectifying circuit is used for converting input alternating current into direct current;

a conversion circuit for converting an output voltage of the rectifying circuit;

the control circuit is used for controlling the working mode of the charging and discharging circuit according to the output power of the rectifying circuit and the input power of the converting circuit; the working mode comprises a charging mode, a discharging mode and a non-working mode;

and a charge and discharge circuit for charging according to the output current of the rectifier circuit in a charge mode, discharging to the inverter circuit in a discharge mode, and stopping operation in a non-operation mode.

In a second aspect, the present application further provides a circuit control method, where the circuit control method is applied to the power supply circuit of the first aspect, and the method includes:

the rectifying circuit converts alternating current input by the rectifying circuit into direct current;

the conversion circuit converts the output voltage of the rectifying circuit;

the control circuit controls the working mode of the charging and discharging circuit according to the output power of the rectifying circuit and the input power of the converting circuit; the working mode comprises a charging mode, a discharging mode and a non-working mode;

the charge and discharge circuit is charged according to an output current of the rectifier circuit in a charge mode, discharges to the inverter circuit in a discharge mode, and stops operating in a non-operation mode.

In a third aspect, the present application further provides a power supply apparatus including the power supply circuit of the first aspect.

In a fourth aspect, the present application further provides an electronic device including the power supply apparatus of the third aspect.

According to the power supply circuit, the circuit control method, the power supply device and the electronic equipment, the charging and discharging circuit in the power supply circuit is connected between the rectifying circuit and the converting circuit in parallel, and the working mode of the charging and discharging circuit is controlled by the control circuit according to the output power of the rectifying circuit and the input power of the converting circuit, so that energy can flow into the charging and discharging circuit when energy needs to be stored, and energy can flow out of the charging and discharging circuit when energy needs to be released. It is thus clear that only a small part of energy can pass through charge and discharge circuit among the power supply circuit that this application embodiment provided, PFC circuit among the traditional art for, the energy storage capacity demand of charge and discharge circuit that this application embodiment provided is less, consequently, energy storage circuit's volume is less among the charge and discharge circuit for charge and discharge circuit's volume is less, thereby can reduce power supply circuit's volume.

Drawings

FIG. 1 is a schematic diagram of a power circuit in the prior art;

FIG. 2 is a schematic diagram of a power circuit according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a power supply circuit according to another embodiment of the present application;

fig. 4 is a schematic structural diagram of a power supply circuit according to another embodiment of the present application;

FIG. 5 is a schematic diagram of a power circuit according to another embodiment of the present application;

FIG. 6 is a first schematic diagram of a measurement waveform provided by an embodiment of the present application;

FIG. 7 is a second schematic diagram of a measurement waveform provided by the present embodiment;

FIG. 8 is a schematic diagram of harmonic current components provided in an embodiment of the present application;

fig. 9 is a flowchart illustrating a circuit control method according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of and not restrictive on the broad application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

It will be understood that the terms "comprises/comprising," "includes" or "including," or "having," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or groups thereof.

The power supply circuit provided by the embodiment of the application can be applied to electronic equipment. By way of example, the electronic devices involved in the embodiments of the present application may include, but are not limited to: the floor cleaning machine comprises a power adapter, a biscuit charger, a mobile power supply, a mobile phone, a notebook computer, a tablet computer, an intelligent watch, an intelligent bracelet, a floor cleaning machine, a wireless earphone, an electric toothbrush or a desktop computer.

The function of the PFC circuit is to make the power supply circuit (and its load circuit) behave more like a pure resistor with respect to the ac supply, in particular to make the input voltage and the input current of the power supply circuit (or the output voltage and the output current of the rectifier circuit) as in phase as possible

And the generation of higher harmonics (In) is reduced as much as possible. The total harmonic distortion can be expressed by the following formula (1), and the Power Factor (PF) can be expressed by the following formula (2).

Wherein THD represents total harmonic distortion, I _n Represents the nth harmonic current, I ₁ Representing the fundamental current. Of course, the total harmonic distortion can also be expressed by other modifications of the above formula (1) or equivalent formula, which is not limited in the embodiments of the present application.

Of course, the PF can also be expressed by other modifications of the above formula (2) or equivalent formulas, which are not limited in the embodiments of the present application.

Fig. 1 is a schematic structural diagram of a power supply circuit in the prior art, and as shown in fig. 1, a PFC circuit is connected in series between a rectifier circuit and a converter circuit, wherein two ends of a capacitor in the PFC circuit are connected in series with two input ends of the converter circuit. Because most of energy in the power circuit needs to pass through the PFC circuit, the energy storage capacity requirement in the PFC circuit is high, and therefore the volume of a capacitor and an inductor in the PFC circuit is high, the volume of the PFC circuit is high, and the volume of the power circuit is high.

The embodiment of the application proposes that the charging and discharging circuit is connected between the rectifying circuit and the converting circuit in the power supply circuit in parallel, energy flows into the charging and discharging circuit when the energy needs to be stored is detected, and energy flows out of the charging and discharging circuit when the energy needs to be released is detected. It is thus clear that only a small part of energy can pass through charge and discharge circuit among the power supply circuit that this application embodiment provided, PFC circuit among the traditional art for, the energy storage capacity demand of charge and discharge circuit that this application embodiment provided is less, consequently, energy storage circuit's volume is less among the charge and discharge circuit for charge and discharge circuit's volume is less, thereby can reduce power supply circuit's volume.

The switching transistors involved in the embodiments of the present application may include, but are not limited to, metal-Oxide-Semiconductor Field-Effect transistors (MOS) or switching transistors made of gallium nitride (GaN) material, such as Metal-Semiconductor Field-Effect transistors (MESFETs), heterojunction Field-Effect transistors (HFETs) or modulation-doped Field-Effect transistors (MODFETs), etc.

For convenience of understanding, in the following embodiments of the present application, the power circuit is described by taking each switching tube as an NMOS transistor as an example.

In an embodiment, fig. 2 is a schematic structural diagram of a power supply circuit provided in an embodiment of the present application, and as shown in fig. 2, the power supply circuit in the embodiment of the present application may include: a rectifier circuit 20, a charge and discharge circuit 21, a conversion circuit 22, and a control circuit 23. The rectifier circuit 20 and the converter circuit 22 are connected in series, the charge/discharge circuit 21 is connected in parallel to the rectifier circuit 20 and the converter circuit 22, respectively (that is, the charge/discharge circuit 21 is connected in parallel between the rectifier circuit 20 and the converter circuit 22), and the control circuit 23 is connected to the charge/discharge circuit 21.

A rectifier circuit 20 in the embodiment of the present application, configured to convert input ac power into dc power; and a conversion circuit 22 for converting the output voltage of the rectifying circuit to obtain a target voltage of a desired output. For example, the conversion circuit 22 in the embodiment of the present application may include, but is not limited to, direct Current-Direct Current (DCDC).

The control circuit 23 in this embodiment of the application is configured to control an operation mode of the charging and discharging circuit 21 according to the output power of the rectifying circuit 20 and the input power of the converting circuit 22, where the operation mode may include: a charge mode, a discharge mode, and a non-operational mode.

The charging and discharging circuit 21 in the embodiment of the present application is configured to charge according to the output current of the rectifying circuit 20 in the charging mode, that is, the energy storage circuit in the charging and discharging circuit 21 stores energy; in the discharging mode, the energy is discharged to the conversion circuit, namely the energy is released from the energy storage circuit in the charging and discharging circuit 21; and stops working in the non-working mode, namely the energy storage circuit in the charging and discharging circuit 21 is in an open circuit state so as to stop working.

It should be understood that, in the embodiment of the present application, the control circuit 23 may detect the output power of the rectifying circuit 20 and the input power of the converting circuit 22 through the detection circuit. Illustratively, the detection circuit may include, but is not limited to: a voltage sensor, a current sensor, and/or a resistance-divided detection circuit.

The charging and discharging circuit 21 in the embodiment of the present application may be a bidirectional buck circuit (or referred to as a biback circuit), for example. When the charge and discharge circuit 21 is in the charge mode, the charge and discharge circuit 21 works in the boost mode; when the charge and discharge circuit 21 is in the discharge mode, the charge and discharge circuit 21 operates in buck mode.

In a possible implementation manner, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in a charging mode when it is determined that energy needs to be stored according to the output power of the rectifying circuit 20 and the input power of the converting circuit 22, so that energy flows into the charging and discharging circuit 21 and is stored in the energy storage circuit in the charging and discharging circuit 21. For example, the energy storage circuit referred to in the embodiments of the present application may include, but is not limited to, an inductor and a capacitor.

Illustratively, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the charging mode when the output power of the rectifying circuit 20 is larger than the input power of the converting circuit 22, i.e. when energy storage is required.

As another example, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the charging mode when the output power of the rectifying circuit 20 is greater than the input power of the converting circuit 22, and the difference between the output power and the input power is greater than or equal to a first preset difference, that is, when energy needs to be stored.

In the following embodiments of the present application, the control circuit 23 determines that energy needs to be stored when the output power of the rectifier circuit 20 is greater than the input power of the converter circuit 22.

In another possible implementation, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the discharging mode when it is determined that the energy needs to be released according to the output power of the rectifying circuit 20 and the input power of the converting circuit 22, so that the energy storage circuit in the charging and discharging circuit 21 releases the energy, that is, the energy flows out of the charging and discharging circuit 21.

Illustratively, the control circuit 23 is configured to control the charge and discharge circuit 21 to be in the discharge mode when the output power of the rectifier circuit 20 is smaller than the input power of the converter circuit 22, i.e. when energy needs to be discharged.

As another example, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the discharging mode when the output power of the rectifying circuit 20 is smaller than the input power of the converting circuit 22, and the difference between the input power and the output power is greater than or equal to a second preset difference, that is, energy needs to be released.

In the following embodiments of the present application, the control circuit 23 determines that energy needs to be released when the output power of the rectifier circuit 20 is smaller than the input power of the converter circuit 22.

In another possible implementation, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the non-operating mode when it is determined that neither energy needs to be stored nor released according to the output power of the rectifying circuit 20 and the input power of the converting circuit 22, so that neither energy flows into nor out of the charging and discharging circuit 21.

Illustratively, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the non-operation mode when the output power of the rectifying circuit 20 is equal to the input power of the converting circuit 22, i.e. when neither energy storage nor energy release is required.

As still another example, the control circuit 23 is configured to control the charging and discharging circuit 21 to be in the non-operation mode when an absolute value of a difference between the output power of the rectifying circuit 20 and the input power of the converting circuit 22 is smaller than a third preset difference, i.e., when neither energy storage nor energy release is required.

It should be noted that, in the following embodiments of the present application, the control circuit 23 determines that neither energy needs to be stored nor released when the output power of the rectifier circuit 20 is equal to the input power of the converter circuit 22.

In summary, the power circuit in the embodiment of the present application controls the operation mode of the charging and discharging circuit 21 by connecting the charging and discharging circuit 21 in parallel between the rectifying circuit 20 and the converting circuit 22 and by the control circuit 23 according to the output power of the rectifying circuit 20 and the input power of the converting circuit 22, so that energy flows into the charging and discharging circuit 21 only when energy needs to be stored, and energy flows out of the charging and discharging circuit 21 only when energy needs to be released. It can be seen that, in the power circuit provided in the embodiment of the present application, only a small amount of energy will pass through the charging and discharging circuit 21, and compared with the PFC circuit in the conventional technology, the energy storage capacity requirement of the charging and discharging circuit 21 provided in the embodiment of the present application is smaller, and therefore, the volume of the energy storage circuit in the charging and discharging circuit 21 is smaller, so that the volume of the power circuit can be reduced.

In an embodiment, fig. 3 is a schematic structural diagram of a power supply circuit according to another embodiment of the present application, and based on the above embodiment, relevant contents of the charging and discharging circuit 21 are introduced in this embodiment of the present application. As shown in fig. 3, the charge and discharge circuit 21 in the embodiment of the present application may include: the rectifier circuit 20 and the conversion circuit 22 are connected in parallel with the tank circuit 211, and the rectifier circuit 23 and the tank circuit 211 are connected in parallel with the tank circuit 211.

In a possible implementation manner, the control circuit 23 is configured to control the selection circuit 210 to be in the first conduction state when the output power of the rectification circuit 20 is greater than the input power of the conversion circuit 22, so that the selection circuit 210 enables the output current of the rectification circuit 20 to charge the energy storage circuit 211 in the first conduction state, thereby implementing control of the charging and discharging circuit 21 to be in the discharging mode.

For example, the control circuit 23 may make the selection circuit 210 in the first conduction state by controlling the on/off state of each switching tube in the selection circuit 210, so as to charge the energy storage circuit 211 according to the output current of the rectification circuit 20.

In another possible implementation manner, the control circuit 23 is configured to control the selection circuit 210 to be in the second conduction state when the output power of the rectification circuit 20 is smaller than the input power of the conversion circuit 22, so that the selection circuit 210 discharges the energy storage circuit 211 in the second conduction state, thereby controlling the charging and discharging circuit 21 to be in the discharging mode.

For example, the control circuit 23 may make the selection circuit 210 in the second conduction state by controlling the on/off states of the switch tubes in the selection circuit 210, so as to control the energy storage circuit 211 to discharge.

In another possible implementation manner, the control circuit 23 is configured to control the selection circuit 210 to be in the open circuit state when the output power of the rectification circuit 20 is equal to the input power of the conversion circuit 22, so as to stop the operation of the energy storage circuit 211 in the charging and discharging circuit 21 (neither discharging nor charging), thereby controlling the charging and discharging circuit 21 to be in the non-operation mode.

For example, the control circuit 23 may control each switch in the selection circuit 210 to be in the off state, so that the selection circuit 210 is in the off state.

In the embodiment of the present application, the control circuit 23 is configured to charge the energy storage circuit 211 in the charge and discharge circuit 21 when energy needs to be stored, or discharge the energy storage circuit 211 in the charge and discharge circuit 21 when energy needs to be released, by controlling the on/off state of the selection circuit 210 in the charge and discharge circuit 21, so that energy flows into the charge and discharge circuit 21 when energy needs to be stored, and energy flows out of the charge and discharge circuit 21 when energy needs to be released. It can be seen that, in the power supply circuit provided in the embodiment of the present application, only a small amount of energy will pass through the charging and discharging circuit 21, and the energy storage capacity requirement of the charging and discharging circuit 21 provided in the embodiment of the present application is small, so that the volume of the energy storage circuit 211 in the charging and discharging circuit 21 is small, and thus the volume of the power supply circuit can be reduced.

In an embodiment, fig. 4 is a schematic structural diagram of a power supply circuit provided in another embodiment of the present application, and based on the foregoing embodiment, related contents of the energy storage circuit 211 are described in this embodiment of the present application. As shown in fig. 4, the energy storage circuit 211 in the embodiment of the present application may include: the rectifier circuit comprises an inductor L and a capacitor C1, wherein one end of the inductor L is connected with the rectifier circuit 20, the other end of the inductor L is connected with a first end of a selection circuit 210, a second end of the selection circuit 210 is connected with one end of the capacitor C1, and a third end of the selection circuit 210 and the other end of the capacitor C1 are both grounded. It should be understood that the control circuit 23 is connected to the fourth terminal of the selection circuit 210 for controlling the on/off state of each switching tube in the selection circuit 210.

In a possible implementation manner, the control circuit 23 is configured to control the selection circuit 210 to be in the first conduction state when the output power of the rectification circuit 20 is greater than the input power of the conversion circuit 22, so that the selection circuit 210 can control the rectification circuit 20 to charge the inductor L in the first conduction state, and can control the output current of the rectification circuit 20 to charge the capacitor C1 until the current of the inductor L reaches the first threshold.

Illustratively, the control circuit 23 is configured to, when the output power of the rectifier circuit 20 is greater than the input power of the converter circuit 22, control the selection circuit 210 to be in the first conduction state, so as to turn on the path between the rectifier circuit 20 and the inductor L, and turn off the path between the inductor L and the capacitor C, so that the output current of the rectifier circuit 20 charges the inductor L, and the path between the inductor L and the capacitor C1 is turned on until the current of the inductor L reaches the first threshold value, so that the output current of the rectifier circuit 20 charges the capacitor C1.

In this implementation, the control circuit 23 controls the selection circuit 210 to be in the first conduction state, so that the rectifier circuit 20 charges the inductor L, and when the current of the inductor L reaches the first threshold, the process of controlling the output current of the rectifier circuit 20 to charge the capacitor C1 is a periodically repeated process. The first threshold may be changed according to the output power of the rectifier circuit 20, that is, the first threshold may not be the same in different periods, or the boost current in the embodiment of the present application may be dynamically adjustable.

It should be understood that, in the embodiment of the present application, the control circuit 23 may detect the current of the inductor L by controlling the detection circuit.

In another possible implementation manner, the control circuit 23 is configured to control the selection circuit 210 to be in the second conduction state when the output power of the rectification circuit 20 is smaller than the input power of the conversion circuit 22, so that the selection circuit 210 can control the capacitor C1 to discharge in the second conduction state, and can control the inductor L to discharge until the current of the inductor L reaches the second threshold.

Illustratively, the control circuit 23 is configured to, when the output power of the rectifying circuit 20 is smaller than the input power of the converting circuit 22, control the selecting circuit 210 to be in the second conducting state, so as to conduct the path between the inductor L and the capacitor C1, so as to facilitate the capacitor C1 to discharge, conduct the path between the rectifying circuit 20 and the inductor L until the current of the inductor L reaches the second threshold, and turn off the path between the inductor L and the capacitor C1, so as to facilitate the inductor L to discharge.

It should be noted that, in this implementation, the control circuit 23 controls the selection circuit 210 to be in the second conduction state, so that the capacitor C1 discharges, and the process of controlling the inductor L to discharge is a periodically repeated process when the current of the inductor L reaches the second threshold. The second threshold may be changed according to the output power of the rectifier circuit 20, that is, the second threshold may not be the same in different periods, or the buck current in the embodiment of the present application is dynamically adjustable.

In another possible implementation, the control circuit 23 is configured to control the selection circuit 210 to be in the open state when the output power of the rectifying circuit 20 is equal to the input power of the converting circuit 22, so as to break the path between the rectifying circuit 20 and the inductor L and the path between the capacitor C1 and the inductor L, so that no energy enters the charging and discharging circuit 21.

In this embodiment, the control circuit 23 controls the selection circuit 210 to be in the open state, so that the process of disconnecting the path between the rectification circuit 20 and the inductor L and the path between the capacitor C1 and the inductor L is a periodically repeated process.

In this embodiment, the control circuit 23 charges the inductor L and the capacitor C1 in the energy storage circuit 211 when energy needs to be stored by controlling the on-off state of the selection circuit 210 in the charge and discharge circuit 21, or discharges the inductor L and the capacitor C1 in the energy storage circuit 211 when energy needs to be released, so that energy flows into the energy storage circuit 211 when energy needs to be stored, and energy flows out of the energy storage circuit 211 when energy needs to be released. It can be seen that, in the power supply circuit provided in the embodiment of the present application, only a small amount of energy can pass through the energy storage circuit 211, and the energy storage capacity requirement of the energy storage circuit 211 provided in the embodiment of the present application is small, so that the volumes of the capacitor C1 and the inductor L in the energy storage circuit 211 are small, the volume of the charging and discharging circuit 21 is small, and the volume of the power supply circuit can be reduced.

In an embodiment, fig. 5 is a schematic structural diagram of a power supply circuit provided in another embodiment of the present application, and on the basis of the above embodiment, relevant contents of the selection circuit 210 are described in this embodiment of the present application. As shown in fig. 5, the selection circuit 210 in the embodiment of the present application may include a first switch Q1 and a second switch Q2, wherein a first end of the first switch Q1 is connected to the inductor L and a second end of the second switch Q2, a second end of the first switch Q1 is connected to the capacitor C1, a first end of the second switch Q2 is grounded, and a third end of the first switch Q1 and a third end of the second switch Q2 are both connected to the control circuit 23.

It should be understood that the control circuit 23 is configured to send a first control signal to the first switch tube Q1 and/or send a second control signal to the second switch tube Q2, wherein the first control signal is used to control the on/off state of the first switch tube Q1, and the second control signal is used to control the on/off state of the second switch tube Q2. Illustratively, the control signal (e.g., the first control signal or the second control signal) referred to in the embodiments of the present application may include, but is not limited to, a Pulse Width Modulation (PWM) signal.

In a possible implementation manner, the control circuit 23 is configured to, when the output power of the rectifying circuit 20 is greater than the input power of the converting circuit 22, turn on the path between the rectifying circuit 20 and the inductor L by controlling the second switching tube Q2 to be turned on, and turn off the path between the inductor L and the capacitor C1 by controlling the first switching tube Q1 to be turned off, so that the output current of the rectifying circuit 20 charges the inductor L, and when the current of the inductor L reaches the first threshold value, turn on the first switching tube Q1 and turn off the second switching tube Q2 to turn on the path between the inductor L and the capacitor C1, so that the output current of the rectifying circuit 20 charges the capacitor C1.

In another possible implementation manner, the control circuit 23 is configured to, when the output power of the rectifier circuit 20 is smaller than the input power of the converter circuit 22, turn on the first switch tube Q1 and turn off the second switch tube Q2 to turn on the path between the inductor L and the capacitor C1, so as to discharge the capacitor C1, and, when the current of the inductor reaches the second threshold, turn off the first switch tube Q1 and turn on the second switch tube Q2 to turn on the path between the rectifier circuit 20 and the inductor L and turn off the path between the inductor L and the capacitor C1, so as to discharge the inductor L.

It should be noted that, when the output power of the rectifying circuit 20 is smaller than the input power of the converting circuit 22, the control circuit 23 may also be configured to turn on the path between the rectifying circuit 20 and the inductor L by controlling the first switching tube Q1 to be turned off and the second switching tube Q2 to be turned on, and turn on the path between the inductor L and the capacitor C1 by controlling the first switching tube Q1 to be turned on and the second switching tube Q2 to be turned off until the current of the inductor reaches the third threshold, so as to facilitate the discharging of the capacitor C1. Further, until the current of the inductor reaches the second threshold, the control circuit 23 controls the first switch tube Q1 to be turned off and the second switch tube Q2 to be turned on, so as to turn on the path between the rectifying circuit 20 and the inductor L and turn off the path between the inductor L and the capacitor C1, so as to facilitate the discharge of the inductor L.

In another possible implementation manner, the control circuit 23 is configured to control both the first switching tube Q1 and the second switching tube Q2 to be turned off when the output power of the rectifying circuit 20 is equal to the input power of the converting circuit 22, so as to break a path between the rectifying circuit 20 and the inductor L and a path between the capacitor C1 and the inductor L.

For the sake of understanding, in the following embodiments of the present application, the operation of the power supply circuit is described.

As shown in fig. 5, the power supply circuit in the embodiment of the present application may further include: a decoupling circuit 24, wherein one end of the decoupling circuit is connected with the rectifying circuit 20, the other end of the decoupling circuit 20 is grounded, the decoupling circuit 24 is used for reducing mutual interference between the front stage circuit and the rear stage circuit of the decoupling circuit 20, wherein the front stage circuit of the decoupling circuit 20 can comprise the rectifying circuit 20, and the rear stage circuit of the decoupling circuit 20 can comprise the converting circuit 22. Illustratively, decoupling circuit 24 may include, but is not limited to: such as the capacitance C2 shown in fig. 5.

Fig. 6 is a first schematic diagram of a measurement waveform provided in the embodiment of the present application, as shown in fig. 6, 1) assuming that between time periods t1 and t2, when the control circuit 23 detects that the output power of the rectifying circuit 20 is equal to the input power of the converting circuit 22 through the detection circuit, the first switching tube Q1 and the second switching tube Q2 may be controlled to be both off, so that the path between the rectifying circuit 20 and the inductor L and the path between the capacitor C1 and the inductor L are disconnected, and the charging and discharging circuit 21 is in the non-operating mode.

2) Assuming that between the time periods t2 and t3, when the control circuit 23 detects that the output power of the rectifying circuit 20 is greater than the input power of the converting circuit 22 through the detection circuit, the second switching tube Q2 is controlled to be on and the first switching tube Q1 is controlled to be off, so that the output current of the rectifying circuit 20 charges the inductor L (the current I1 of the inductor flows from left to right), and when the current I1 of the inductor L increases from zero to the first threshold, the first switching tube Q1 is controlled to be on and the second switching tube Q2 is controlled to be off, so that the output current of the rectifying circuit 20 charges the capacitor C1 through the inductor L (the current I1 of the inductor flows from left to right). Further, when the current I1 of the inductor decreases from the first threshold to zero, the control circuit 23 controls the second switching tube Q2 to be turned on and the first switching tube Q1 to be turned off so as to facilitate the output current of the rectifying circuit 20 to charge the inductor L, \8230;, and so on, periodically cycle until the output power of the rectifying circuit 20 is not greater than the input power of the converting circuit 22. As shown in fig. 6, when the charge/discharge circuit 21 is in the charge mode, the voltage V1 of the capacitor C1 and the voltage V2 of the capacitor C2 gradually increase.

It should be understood that the first threshold may be varied with the output power of the rectifier circuit 20, so that the boost current in the embodiment of the present application is dynamically adjustable, so that the waveform of the output current I3 of the rectifier circuit 20 may be more optimized, so that the waveform of the output current I3 is closer to the desired waveform (such as a sine wave).

3) Assuming that between the time periods t3 and t4, when the control circuit 23 detects that the output power of the rectifying circuit 20 is equal to the input power of the converting circuit 22 through the detection circuit, the charging and discharging circuit 21 may be in the non-operating mode by controlling both the first switching tube Q1 and the second switching tube Q2 to be turned off, so as to turn off the path between the rectifying circuit 20 and the inductor L and the path between the capacitor C1 and the inductor L. As shown in fig. 6, when the charge/discharge circuit 21 is in the non-operation mode, the voltage V1 of the capacitor C1 remains unchanged, but the voltage V2 of the capacitor C2 gradually decreases.

4) Assuming that the control circuit 23 controls the first switch Q1 to be turned on and the second switch Q2 to be turned off when the detection circuit detects that the output power of the rectifying circuit 20 is smaller than the input power of the converting circuit 22 between the time periods t4 and t5, so as to discharge the capacitor C1 (the current I2 of the inductor flows from right to left), and controls the first switch Q1 to be turned off and the second switch Q2 to be turned on so as to discharge the inductor L (the current I2 of the inductor flows from right to left) until the current I2 of the inductor L "increases" from zero to a second threshold. Further, when the current I2 of the inductor L is decreased from the second threshold value "to" zero ", the control circuit 23 controls the first switching tube Q1 to be turned on and the second switching tube Q2 to be turned off so as to discharge the capacitor C1, \ 8230 \ 8230;, and this is periodically cycled until the output power of the rectifying circuit 20 is not less than the input power of the converting circuit 22. As shown in fig. 6, when the charge/discharge circuit 21 is in the discharge mode, the voltage V1 of the capacitor C1 is gradually decreased, but the voltage V2 of the capacitor C2 is gradually increased and then gradually decreased.

It should be understood that the second threshold may be varied according to the output power of the rectifier circuit 20, so that the buck current in the embodiment of the present application is dynamically adjustable, so that the waveform of the output current I3 of the rectifier circuit 20 may be more optimized, so that the waveform of the output current I3 is closer to the desired waveform (e.g., a sine wave).

It should be understood that if the inductor current flows from left to right as a positive current, the first threshold in the embodiment of the present application is a positive integer, and the second threshold is a negative integer.

It should be noted that the operation process of the following time period is similar to the process of the time periods t1-t5, and is not described here.

Fig. 7 is a schematic diagram of a second measurement waveform provided by the embodiment of the present application, and fig. 8 is a schematic diagram of a harmonic current component provided by the embodiment of the present application, and with reference to fig. 7 and fig. 8, in the embodiment of the present application, by connecting the charge and discharge circuit 21 in parallel between the rectifier circuit 20 and the converter circuit 22, and then controlling the on-off states of the first switching tube Q1 and the second switching tube Q2 in the selection circuit 210 through the control circuit 23, the operation mode and the current magnitude of the charge and discharge circuit 21 are adjusted, so that not only the volume of the charge and discharge circuit 21 can be reduced, but also the waveform of the output current I3 of the rectifier circuit 20 can be further optimized through controlling the operation mode of the charge and discharge circuit 21, so that the waveform of the output current I3 is closer to an expected waveform (such as a sine wave), as shown in fig. 7, the harmonic current measured after the output current I3 is fourier transformed is smaller.

In summary, in the embodiment of the present application, only a small amount of energy passes through the charge and discharge circuit 21, and compared to the PFC circuit in the conventional technology, the energy storage capacity requirement of the charge and discharge circuit 21 provided in the embodiment of the present application is smaller, and therefore, the capacity of the capacitor C1 in the charge and discharge circuit 21 is smaller, so that the capacitor C1 in the embodiment of the present application may select a high voltage resistant ceramic capacitor or a thin film capacitor, and the like, and in combination with the parallel connection of the charge and discharge circuit 21, the variation range of the voltage V1 of the capacitor C1 in the embodiment of the present application shown in fig. 7 may be very large.

It should be appreciated that since the output power of the rectifier circuit 20 varies regularly with the power frequency cycle, the input power to the inverter circuit 22 is relatively constant, and therefore the energy required to be stored and released during each half of the power frequency cycle is a constant value Δ W =1/2 × c (Vmax 2-Vmin 2).

Since the variation range of the voltage V1 of the capacitor C1 in the embodiment of the present application may be large, that is, the difference between the highest voltage Vmax and the lowest voltage Vmin is large, when the same energy needs to be stored, the capacity of the capacitor C1 in the embodiment of the present application may be small compared to the energy storage capacitor in the PFC circuit.

For example, the voltage V1 of the capacitor C1 in the embodiment of the present application may fluctuate within a range from 200V to 410V, which is far beyond the fluctuation range (usually within 10V) of the energy storage capacitor of the conventional PFC circuit, and therefore, the capacitance of C1 may be greatly reduced.

In the conventional technology, a PFC circuit is connected in series between a rectification circuit and a conversion circuit, wherein two ends of an inductor in the PFC circuit are connected in series between the rectification circuit and the conversion circuit. Since both the "output power" current and the "stored energy" current in the power circuit need to pass through the inductance in the PFC circuit (the "energy released" current flows from the capacitance in the PFC circuit to the conversion circuit). In contrast, in the embodiment of the present application, by connecting the charging and discharging circuit 21 in parallel between the rectifying circuit 20 and the converting circuit 22 in the power supply circuit, the current I1 of "stored energy" and the current I2 of "released energy" will pass through the inductor L in the charging and discharging circuit 21, but the current I4 of "output power" will not pass through the charging and discharging circuit 21, that is, the current flowing through the inductor L in the embodiment of the present application is reduced, so that the Series Equivalent Resistance (ESR) of the inductor L in the embodiment of the present application can be made larger under the same loss, and thus the volume of the inductor L can be made smaller.

In a conventional PFC circuit, the capacitance of the capacitor is positively correlated with the input power of the inverter circuit, for example, if the input power of the inverter circuit is 100w, the capacitance of the capacitor in the PFC circuit is 100u; when the input power of the converter circuit is 80w, the capacitance of the capacitor in the PFC circuit is 80u. In contrast, with the power supply circuit provided by the embodiment of the present application, the capacitance of the capacitor C1 in the charge and discharge circuit may be small (for example, 6 u), and the capacitance of the inductor L1 may also be small (for example, 8mm in diameter and 5mm in thickness), so that the 17625-1D class device standard may be met.

In summary, compared with the conventional PFC circuit, the volume of the capacitor and the inductor in the charging and discharging circuit 21 in the embodiment of the present application may be smaller, so that the volume of the charging and discharging circuit 21 is smaller, and the volume of the power supply circuit is smaller, thereby providing a better PFC scheme for the electronic device with high power and small volume.

It should be understood that, in the embodiments of the present application, the input power of the conversion circuit is described as being relatively constant, and if the input power of the conversion circuit may not be constant (for example, the ripple charging of the first generation of biscuit charger, etc.), the power supply circuit provided in the embodiments of the present application may reduce the required "stored energy" and/or the required "released energy" to a greater extent, so that the size of the power supply circuit may be further reduced.

In an embodiment, fig. 9 is a schematic flowchart of a circuit control method provided in an embodiment of the present application, and the circuit control method in the embodiment of the present application may be applied to the power supply circuit provided in the above embodiment of the present application. As shown in fig. 9, the method of the embodiment of the present application may include the following steps:

step S901, the rectifier circuit converts the ac power input by the rectifier circuit into dc power;

step S902, the conversion circuit converts the output voltage of the rectifier circuit;

and step S903, the control circuit controls the working mode of the charge and discharge circuit according to the output power of the rectifying circuit and the input power of the conversion circuit.

The operation mode in the embodiment of the present application includes a charge mode, a discharge mode, and a non-operation mode.

In step S904, the charge and discharge circuit is charged according to the output current of the rectifier circuit in the charge mode, is discharged to the inverter circuit in the discharge mode, and stops operating in the non-operating mode.

In one embodiment, the control circuit controls the operation mode of the charge and discharge circuit according to the output power of the rectification circuit and the input power of the conversion circuit, and comprises:

when the output power is larger than the input power, the control circuit controls the charge-discharge circuit to be in a charge mode; or when the output power is smaller than the input power, controlling the charge-discharge circuit to be in a discharge mode; or,

when the output power of the control circuit is smaller than the input power, the control circuit controls the charge-discharge circuit to be in a discharge mode; or,

and when the output power is equal to the input power, the control circuit controls the charge and discharge circuit to be in a non-working mode.

In one embodiment, the control circuit controls the charging and discharging circuit to be in the charging mode when the output power is larger than the input power, and includes:

when the output power is larger than the input power, the control circuit controls the selection circuit to be in a first conduction state;

the selection circuit enables the output current of the rectifying circuit to charge the energy storage circuit in the first conduction state.

In one embodiment, the selection circuit is in a first conduction state, so that the output current of the rectification circuit charges the energy storage circuit, and the selection circuit comprises:

the selection circuit controls the rectifying circuit to charge the inductor in a first conduction state, and controls the output current of the rectifying circuit to charge the capacitor under the condition that the current of the inductor reaches a first threshold value.

In one embodiment, the selection circuit controls the rectification circuit to charge the inductor in the first conduction state, and controls the output current of the rectification circuit to charge the capacitor until the current of the inductor reaches the first threshold value, including:

the selection circuit switches on a path between the rectification circuit and the inductor in a first conduction state and switches off the path between the inductor and the capacitor, so that the output current of the rectification circuit charges the inductor, and the path between the inductor and the capacitor is switched on until the current of the inductor reaches a first threshold value, so that the output current of the rectification circuit charges the capacitor.

In one embodiment, the selection circuit switches on a path between the rectifier circuit and the inductor and switches off a path between the inductor and the capacitor in a first conduction state, so that the output current of the rectifier circuit charges the inductor, and switches on a path between the inductor and the capacitor until the output current of the rectifier circuit charges the capacitor under the condition that the current of the inductor reaches a first threshold value, including:

when the output power is greater than the input power, the control circuit controls the second switching tube in the selection circuit to be connected and the first switching tube to be disconnected, so that the output current of the rectification circuit charges the inductor, and the first switching tube is controlled to be connected and the second switching tube is controlled to be disconnected until the current of the inductor reaches a first threshold value, so that the output current of the rectification circuit charges the capacitor.

In one embodiment, the control circuit controls the charge and discharge circuit to be in the discharge mode when the output power is smaller than the input power, and includes:

when the output power of the control circuit is smaller than the input power, the control circuit controls the selection circuit to be in a second conduction state;

the selection circuit discharges the tank circuit in the second conduction state.

In one embodiment, the selection circuit in the second conductive state causes the tank circuit to discharge, comprising:

the selection circuit controls the capacitor to discharge in the second conduction state until the inductor current reaches the second threshold value, and controls the inductor to discharge.

In one embodiment, the selection circuit controls the capacitor to discharge in the second conduction state until the inductor controls the inductor to discharge when the current of the inductor reaches a second threshold value, including:

the selection circuit conducts a path between the inductor and the capacitor in a second conduction state to enable the capacitor to discharge, conducts the path between the rectification circuit and the inductor until the current of the inductor reaches a second threshold value, and turns off the path between the inductor and the capacitor to enable the inductor to discharge.

In one embodiment, the selecting circuit switches on the path between the inductor and the capacitor in the second conducting state, so that the capacitor discharges, switches on the path between the rectifying circuit and the inductor until the current of the inductor reaches the second threshold, and switches off the path between the inductor and the capacitor, so that the inductor discharges, including:

when the output power is smaller than the input power, the control circuit controls the first switch tube in the selection circuit to be switched on and the second switch tube to be switched off, so that the capacitor discharges, and the first switch tube is controlled to be switched off and the second switch tube is controlled to be switched on under the condition that the current of the inductor reaches a second threshold value, so that the inductor discharges.

In one embodiment, the control circuit controls the charge and discharge circuit to be in the non-operation mode when the output power is equal to the input power, and includes:

when the output power is equal to the input power, the control circuit controls the selection circuit to be in an open circuit state;

the selection circuit stops the operation of the tank circuit in the open state.

In one embodiment, the selection circuit is in an open state to disable the tank circuit, comprising:

the selection circuit breaks a path between the rectifying circuit and the inductor and a path between the capacitor and the inductor in an open circuit state.

In one embodiment, the selection circuit breaks a path between the rectifying circuit and the inductor and a path between the capacitor and the inductor in an open circuit state, including:

when the output power is equal to the input power, the control circuit controls the first switch tube and the second switch tube in the selection circuit to be disconnected.

The circuit control method provided by the embodiment of the present application can be applied to the power circuit provided by the above embodiment of the present application, and the implementation principle and the technical effect are similar, which are not described herein again.

In an embodiment, a power supply apparatus is provided, which includes the power supply circuit provided in the above embodiments of the present application, and the implementation principle and technical effects are similar, and are not described herein again.

In an embodiment, an electronic device is provided, which includes the power supply apparatus provided in the above embodiments of the present application, and the implementation principle and technical effects are similar, and are not described herein again.

All possible combinations of the technical features in the above embodiments may not be described for the sake of brevity, but should be considered as being within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A power supply circuit, characterized in that the power supply circuit comprises: the charging and discharging circuit is connected with the rectifying circuit and the converting circuit in parallel respectively, and the control circuit is connected with the charging and discharging circuit;

the conversion circuit is used for converting the output voltage of the rectification circuit;

the control circuit is used for controlling the working mode of the charging and discharging circuit according to the output power of the rectifying circuit and the input power of the converting circuit; wherein the working mode comprises a charging mode, a discharging mode and a non-working mode;

the charging and discharging circuit is used for charging according to the output current of the rectifying circuit in the charging mode, discharging to the conversion circuit in the discharging mode and stopping working in the non-working mode.

2. The circuit of claim 1, wherein the control circuit is configured to: when the output power is greater than the input power, controlling the charging and discharging circuit to be in a charging mode; or,

when the output power is smaller than the input power, controlling the charge and discharge circuit to be in a discharge mode; or,

and when the output power is equal to the input power, controlling the charge and discharge circuit to be in a non-working mode.

3. The circuit of claim 2, wherein the charging and discharging circuit comprises: the selection circuit is connected with the control circuit and the energy storage circuit respectively, and the energy storage circuit is connected with the rectification circuit and the conversion circuit in parallel;

the control circuit is used for controlling the selection circuit to be in a first conduction state when the output power is larger than the input power; when the output power is smaller than the input power, controlling the selection circuit to be in a second conduction state; when the output power is equal to the input power, controlling the selection circuit to be in an open circuit state;

the selection circuit is used for enabling the output current of the rectifying circuit to charge the energy storage circuit in the first conduction state; in the second conducting state, discharging the tank circuit; and in the open-circuit state, stopping the energy storage circuit.

4. The circuit of claim 3, wherein the tank circuit comprises an inductor and a capacitor, one end of the inductor is connected to the rectifying circuit, the other end of the inductor is connected to the first end of the selection circuit, the second end of the selection circuit is connected to one end of the capacitor, and the third end of the selection circuit and the other end of the capacitor are both grounded;

the selection circuit is used for controlling the rectifying circuit to charge the inductor in the first conduction state, and controlling the output current of the rectifying circuit to charge the capacitor under the condition that the current of the inductor reaches a first threshold value; or,

the selection circuit is used for controlling the capacitor to discharge in the second conduction state until the current of the inductor reaches a second threshold value, and controlling the inductor to discharge; or,

the selection circuit is used for disconnecting the path between the rectifying circuit and the inductor and the path between the capacitor and the inductor in the open circuit state.

5. The circuit according to claim 4, wherein the selection circuit is configured to, in the first conducting state, turn on the path between the rectifying circuit and the inductor and turn off the path between the inductor and the capacitor, so that the output current of the rectifying circuit charges the inductor, and, in a case where the current of the inductor reaches the first threshold, turn on the path between the inductor and the capacitor, so that the output current of the rectifying circuit charges the capacitor; or,

the selection circuit is configured to, in the second conduction state, turn on a path between the inductor and the capacitor, so that the capacitor discharges, turn on the path between the rectifier circuit and the inductor until the current of the inductor reaches the second threshold, and turn off the path between the inductor and the capacitor, so that the inductor discharges.

6. The circuit of claim 5, wherein the selection circuit comprises a first switch tube and a second switch tube, wherein a first terminal of the first switch tube is connected to the inductor and a second terminal of the second switch tube, respectively, a second terminal of the first switch tube is connected to the capacitor, a first terminal of the second switch tube is grounded, and a third terminal of the first switch and a third terminal of the second switch are both connected to the control circuit;

the control circuit is configured to control the second switching tube to be turned on and the first switching tube to be turned off when the output power is greater than the input power, so that the output current of the rectifier circuit charges the inductor, and control the first switching tube to be turned on and the second switching tube to be turned off when the current of the inductor reaches the first threshold, so that the output current of the rectifier circuit charges the capacitor; or,

the control circuit is configured to control the first switching tube to be turned on and the second switching tube to be turned off when the output power is smaller than the input power, so that the capacitor discharges, and control the first switching tube to be turned off and the second switching tube to be turned on when the current of the inductor reaches the second threshold value, so that the inductor discharges; or,

the control circuit is used for controlling the first switch tube and the second switch tube to be switched off when the output power is equal to the input power.

7. The circuit of any one of claims 1-6, wherein the power circuit further comprises: one end of the decoupling circuit is connected with the rectifying circuit, and the other end of the decoupling circuit is grounded;

the decoupling circuit is used for reducing mutual interference between the rectifying circuit and the converting circuit.

8. A circuit control method applied to the power supply circuit according to any one of claims 1 to 7, the method comprising:

the conversion circuit converts the output voltage of the rectification circuit;

the control circuit controls the working mode of the charging and discharging circuit according to the output power of the rectifying circuit and the input power of the converting circuit; wherein the working mode comprises a charging mode, a discharging mode and a non-working mode;

the charging and discharging circuit is charged according to the output current of the rectifying circuit in the charging mode, discharges to the converting circuit in the discharging mode, and stops working in the non-working mode.

9. The method of claim 8, wherein the controlling circuit controls the operation mode of the charging and discharging circuit according to the output power of the rectifying circuit and the input power of the converting circuit, and comprises:

when the output power is greater than the input power, the control circuit controls the charging and discharging circuit to be in a charging mode; or,

when the output power is smaller than the input power, the control circuit controls the charge and discharge circuit to be in a discharge mode; or,

10. The method of claim 9, wherein the control circuit controls the charging and discharging circuit to be in a charging mode when the output power is greater than the input power, comprising:

when the output power is greater than the input power, the control circuit controls the selection circuit to be in a first conduction state;

and the selection circuit enables the output current of the rectifying circuit to charge the energy storage circuit in the first conduction state.

11. The method of claim 10, wherein the selection circuit in the first conducting state causes the output current of the rectifier circuit to charge a tank circuit, comprising:

the selection circuit controls the rectification circuit to charge the inductor in the first conduction state, and controls the output current of the rectification circuit to charge the capacitor under the condition that the current of the inductor reaches a first threshold value.

12. The method of claim 11, wherein the selection circuit controls the rectifier circuit to charge an inductor in the first conducting state, and controls an output current of the rectifier circuit to charge a capacitor in a case where a current of the inductor reaches a first threshold, comprising:

the selection circuit switches on a path between the rectification circuit and the inductor and switches off a path between the inductor and the capacitor in the first conduction state, so that the output current of the rectification circuit charges the inductor, and the path between the inductor and the capacitor is switched on until the current of the inductor reaches the first threshold value, so that the output current of the rectification circuit charges the capacitor.

13. The method of claim 12, wherein the selection circuit turns on a path between the rectifier circuit and the inductor and turns off a path between the inductor and the capacitor in the first conduction state, so that the output current of the rectifier circuit charges the inductor, and turns on a path between the inductor and the capacitor until the output current of the rectifier circuit charges the capacitor when the current of the inductor reaches the first threshold, comprising:

when the output power is greater than the input power, the control circuit controls the second switching tube in the selection circuit to be connected and the first switching tube to be disconnected, so that the output current of the rectification circuit charges the inductor, and the first switching tube is controlled to be connected and the second switching tube is controlled to be disconnected until the current of the inductor reaches the first threshold value, so that the output current of the rectification circuit charges the capacitor.

14. The method of claim 9, wherein the control circuit controls the charge and discharge circuit to be in a discharge mode when the output power is less than the input power, comprising:

when the output power is smaller than the input power, the control circuit controls the selection circuit to be in a second conduction state;

15. The method of claim 14, wherein the selection circuit, in the second conductive state, discharges a tank circuit, comprising:

and the selection circuit controls the capacitor to discharge in the second conduction state until the inductor discharge is controlled under the condition that the current of the inductor reaches a second threshold value.

16. The method of claim 15, wherein the selection circuit controls the capacitor to discharge in the second conducting state until the inductor current reaches a second threshold, and wherein the selecting circuit controls the inductor to discharge comprises:

the selection circuit conducts a path between the inductor and the capacitor in the second conduction state, so that the capacitor discharges, conducts the path between the rectification circuit and the inductor under the condition that the current of the inductor reaches the second threshold value, and turns off the path between the inductor and the capacitor, so that the inductor discharges.

17. The method of claim 16, wherein the selection circuit in the second conducting state turns on a path between the inductor and the capacitor to discharge the capacitor until the inductor current reaches the second threshold, turns on a path between the rectifying circuit and the inductor, and turns off a path between the inductor and the capacitor to discharge the inductor, comprising:

when the output power is smaller than the input power, the control circuit controls a first switch tube in the selection circuit to be switched on and a second switch tube in the selection circuit to be switched off, so that the capacitor discharges, and when the current of the inductor reaches the second threshold value, the control circuit controls the first switch tube to be switched off and the second switch tube to be switched on, so that the inductor discharges.

18. The method of claim 9, wherein the control circuit controls the charging and discharging circuit to be in a non-operating mode when the output power is equal to the input power, comprising:

and the selection circuit stops the energy storage circuit in the open-circuit state.

19. The method of claim 18, wherein the selection circuit deactivates the tank circuit in the open state, comprising:

the selection circuit disconnects a path between the rectifying circuit and the inductor and a path between the capacitor and the inductor in the open circuit state.

20. The method of claim 19, wherein the selection circuit breaks a path between the rectifying circuit and an inductor and a path between a capacitor and the inductor in the open circuit state, comprising:

and when the output power is equal to the input power, the control circuit controls the first switch tube and the second switch tube in the selection circuit to be switched off.

21. A power supply device characterized by comprising a power supply circuit according to any one of claims 1-7.

22. An electronic device characterized by comprising the power supply apparatus as claimed in claim 21.