A switching power supply circuit and a charging device

Abstract

The utility model provides a kind of switching power supply circuit and charging device, the utility model provides switching power supply circuit including at least one switch control path, the switch control path includes: voltage input unit and voltage regulating unit.Voltage input unit connects alternating voltage input source, receives alternating voltage, and based on the alternating voltage output direct current output voltage;Voltage regulating unit is parallel with the voltage input unit, and output end connects load, for the output voltage is voltage-regulated and handled, and the output voltage after voltage-regulated handling is used to charge load.The switching power supply circuit of the utility model can improve the charging performance of charging device, for example, charging pile, and circuit design structure is simple, easy to realize, and cost is lower.

Description

Technical Field

[0001] This utility model relates to the technical field of electric vehicle charging, and in particular to a switching power supply circuit and a charging device. Background Technology

[0002] With the rapid development of new energy vehicles and the country's vigorous promotion of electric vehicles, the use of electric vehicles is growing rapidly, and the demand for charging piles, as the infrastructure of the electric vehicle industry, is also gradually increasing.

[0003] The charging module is a core component of a charging pile. It not only provides power to external devices, but also controls and converts the power supply circuit to ensure its stability. The performance of the charging module not only affects the overall performance of the charging pile, but is also closely related to charging safety. Therefore, the design of the charging module is of paramount importance.

[0004] With the increasing driving range of electric vehicles and the desire of car owners to reduce charging time, high-power charging has become an inevitable development trend. Therefore, the output voltage of charging modules needs to be increased, for example, to 1000V. Currently, many manufacturers produce charging modules using a linear design, where rectification, conversion, and boost processes are sequentially connected. If any step or component fails, the entire circuit will be affected. Due to technological limitations, it is impossible to further increase the output voltage and power, thus failing to meet the development trend of charging piles. Utility Model Content

[0005] This utility model mainly provides a switching power supply circuit, which has few components, simple control, and high reliability.

[0006] To solve the above-mentioned technical problems, the first technical solution adopted by this utility model is: to provide a switching power supply circuit, including at least one switching control path, wherein the switching control path includes:

[0007] The voltage input unit is connected to an AC voltage input source, receives AC voltage, and outputs DC output voltage based on the AC voltage.

[0008] A voltage regulating unit, connected in parallel with the voltage input unit and with its output terminal connected to the load, is used to regulate the output voltage and charge the load using the regulated output voltage.

[0009] In one embodiment, the voltage input unit is used to perform power factor correction on the AC voltage to generate the output voltage.

[0010] In one embodiment, the voltage input unit includes:

[0011] The energy storage unit is connected to the AC voltage input source;

[0012] A rectifier bridge unit is connected to the AC voltage input source and is connected in series with the energy storage unit;

[0013] The switching unit is connected in parallel with the rectifier bridge unit;

[0014] In response to the switching unit being turned on, the AC voltage is converted into the DC output voltage by the rectifier bridge unit, the energy storage unit stores the output voltage, and in response to the switching unit being turned off, the energy storage unit releases the output voltage through the rectifier bridge unit.

[0015] In one embodiment, in response to the switching unit being turned on, the voltage regulating unit is in the excitation stage and is used to store the output voltage; in response to the switching unit being turned off, the voltage regulating unit is in the voltage regulating stage and is used to output the voltage after voltage regulation.

[0016] In one embodiment, there are multiple voltage regulating units, and the multiple voltage regulating units are connected in parallel between the energy storage unit and the load.

[0017] In one embodiment, the rectifier bridge unit includes an AC input unit and a DC output unit. The AC input unit includes an AC input terminal connected to the energy storage unit, and the DC output unit includes a DC output terminal connected to the AC voltage input source.

[0018] In one embodiment, the AC voltage includes a positive phase AC voltage or a negative phase AC voltage.

[0019] In one embodiment, the switching power supply circuit includes three switching control paths connected in parallel, wherein two of the switching control paths receive positive AC voltages and the remaining one receives negative AC voltages; or, two of the switching control paths receive negative AC voltages and the remaining one receives positive AC voltages.

[0020] In one embodiment, the rectifier bridge unit includes: an AC input unit and a DC output unit, wherein the AC input unit includes an AC input terminal and the DC output unit includes a DC output terminal;

[0021] The AC input terminal of the rectifier bridge unit in the three switch control paths is connected to the energy storage unit in the corresponding switch control path, and the DC output terminals of the rectifier bridge units in the three switch control paths are interconnected.

[0022] In one embodiment, the first and second path terminals of the switching unit are connected to the rectifier bridge unit in the corresponding switch control path, and the control terminal of the switching unit is connected to the peripheral circuit.

[0023] In one embodiment, the voltage regulating unit includes:

[0024] A first capacitor, the first terminal of which is connected to the rectifier bridge unit;

[0025] A transformer, wherein a first end of the primary coil of the transformer is connected to a second end of the first capacitor, and the second end of the primary coil is connected to the switching unit;

[0026] A diode, wherein the anode of the diode is connected to the first terminal of the secondary coil of the transformer;

[0027] The second capacitor has its first end connected to the cathode of the diode and the first output terminal of the switching power supply circuit, and its second end connected to the second end of the secondary coil and the second output terminal of the switching power supply circuit.

[0028] In one embodiment, the voltage regulating unit further includes an inductor connected in parallel with the primary coil of the transformer.

[0029] To solve the above-mentioned technical problems, the second technical solution adopted by this utility model is to provide a charging device, wherein the charging device includes the switching power supply circuit described in any of the above-mentioned claims.

[0030] The beneficial effects of this invention are as follows: Unlike existing technologies, the switching power supply circuit provided by this invention includes at least one switching control path, which comprises a voltage input unit and a voltage regulation unit. The voltage input unit is connected to an AC voltage input source, receives AC voltage, and outputs a DC output voltage based on the AC voltage. The voltage regulation unit is connected in parallel with the voltage input unit, and its output terminal is connected to a load, used to regulate the output voltage and use the regulated output voltage to charge the load. This switching power supply circuit can improve the charging performance of charging devices such as charging piles, and its circuit design is simple, easy to implement, and low in cost. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1This is a schematic diagram of the first embodiment of the switching power supply circuit of this utility model;

[0033] Figure 2 This is a schematic diagram of the second embodiment of the switching power supply circuit of this utility model;

[0034] Figure 3 This is a schematic diagram of the structure of one embodiment of the charging device of this utility model. Detailed Implementation

[0035] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0036] In the following description, specific details such as particular system architectures, interfaces, and technologies are presented for illustrative purposes rather than for limiting purposes, in order to provide a thorough understanding of this application.

[0037] In this article, the term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, "more" in this article means two or more objects.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0039] Before providing a further detailed description of the embodiments of this application, the nouns and terms involved in the embodiments of this application will be explained, and the nouns and terms involved in the embodiments of this application shall be interpreted as follows.

[0040] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] See Figure 1 , Figure 1 This is a schematic diagram of the structure of a first embodiment of the switching power supply circuit of this utility model. The switching power supply circuit of this embodiment includes at least one switching control path 10. When the switching power supply circuit includes multiple switching control paths 10, the multiple switching control paths 10 have the same structure. This embodiment uses one switching control path 10 as an example for explanation.

[0042] The switch control path 10 includes a voltage input unit 13 and a voltage regulation unit 12. The voltage input unit 13 is connected to an AC voltage input source A, receives AC voltage from the AC voltage input source A, and outputs a DC output voltage based on the AC voltage. The voltage regulation unit 12 is connected in parallel with the rectifier bridge unit 11, and its output terminal is connected to a load. It is used to regulate the output voltage and use the regulated output voltage to charge the load.

[0043] In one specific embodiment, the voltage input unit 13 is used to perform power factor correction on the AC voltage to generate the output voltage. Further, the voltage input unit includes an energy storage unit L, a rectifier bridge unit 11, and a switching unit Q. The energy storage unit L is connected to the AC voltage input source; the rectifier bridge unit 11 is connected to the AC voltage input source and is connected in series with the energy storage unit L; the switching unit Q is connected in parallel with the rectifier bridge unit 11. In response to the switching unit Q being turned on, the AC voltage is converted into the DC output voltage by the rectifier bridge unit 11, and the energy storage unit L stores the output voltage. In response to the switching unit Q being turned off, the energy storage unit L releases the output voltage through the rectifier bridge unit 11.

[0044] Specifically, the energy storage unit L is an inductor. Connected in series with the AC voltage input source, the energy storage unit L utilizes the characteristic that inductor current cannot change abruptly, making the input current waveform closer to a sine wave and reducing current harmonics. When the AC voltage changes, the energy storage unit L suppresses abrupt changes in current, allowing the current to follow the voltage waveform, thus improving the power factor. For example, during the voltage rise phase, the energy storage unit L hinders the rapid rise of current; during the voltage fall phase, it hinders the rapid fall of current. The rectifier bridge unit 11 converts the AC voltage to DC voltage. Working in conjunction with the energy storage unit L, it ensures that the input current flows reasonably in both the positive and negative half-cycles of the AC voltage input source, ensuring that the current and voltage are in phase, further improving the power factor. The circuit's operating state is adjusted by controlling the on and off times (i.e., duty cycle) of the switching unit Q. A suitable control strategy can make the input current track changes in the input voltage, achieving power factor correction. For example, using pulse width modulation (PWM) control, the drive signal of the switching unit Q is adjusted in real time based on the detected input voltage and current signals, making the input current waveform closer to a sine wave and improving the power factor.

[0045] Furthermore, the voltage input unit of this application can also achieve voltage stabilization. Specifically, when the switching unit Q is turned on, the AC voltage is converted into the DC output voltage by the rectifier bridge unit 11, and the energy storage unit L stores the output voltage. Due to the self-inductance characteristic of the inductor, the energy storage unit L impedes the rapid rise of the current, and the current increases slowly. During this process, electrical energy is converted into magnetic field energy and stored in the energy storage unit L. After the switching unit Q is turned off, the energy storage unit releases the output voltage through the rectifier bridge unit. Specifically, after the switching unit Q is turned off, the magnetic field energy stored in the energy storage unit L needs to maintain a constant current (according to Lenz's law, induced electromotive force always opposes the change of current). The energy storage unit L generates a self-induced electromotive force, causing the current to continue flowing, releasing the stored energy into the subsequent circuit, maintaining a stable output voltage, and avoiding a significant drop in output voltage when the switching unit Q is turned off.

[0046] In this embodiment of the invention, an energy storage unit L is provided to suppress current changes, making the current flowing through it more gradual. During AC input or switching of the switching unit Q, the current fluctuates. The energy storage unit L can reduce these fluctuations, making the current continuous and stable, thereby making the rectified DC output voltage more stable and providing a relatively stable input for subsequent circuits, indirectly playing a role in voltage stabilization. Furthermore, a switching unit Q is also provided. By adjusting the duty cycle of the switching unit Q, the energy storage unit L works in conjunction with the switching unit Q to stabilize the output voltage by controlling the amount of energy stored and released during the duty cycle adjustment. For example, when the output voltage decreases, feedback control increases the conduction time of the switching unit Q, allowing the energy storage unit L to store more energy and subsequently release more energy, thereby increasing the output voltage to a stable value.

[0047] The switching power supply circuit of this invention is connected between the AC voltage input source A and the load, and the voltage regulation unit 12 is connected in parallel between the rectifier bridge unit 11 and the load. This allows the output voltage signal to be superimposed and output to the load, thereby improving the charging performance of charging devices such as charging piles to meet the development needs of electric vehicles. Furthermore, the switching power supply circuit can be adjusted according to different application system requirements, making it easy to use. In addition, compared to current front-end PFC and back-end DC / DC charging modules, the circuit design of this application is simple, easy to implement, and has a lower cost. This embodiment uses an energy storage unit L and a switching unit Q to control the voltage regulation unit 12, resulting in a simple structure, easy implementation, and reduced device usage costs.

[0048] Furthermore, this application includes multiple voltage regulating units 12, which are connected in parallel between the energy storage unit L and the load. Specifically, each voltage regulating unit 12 is independent of the others, and the functionality of the entire switching power supply circuit will not be affected by the damage of a single device. Moreover, using one energy storage unit L and one switching unit Q to control the output of multiple voltage regulating units 12 improves device utilization. Furthermore, the input terminals of multiple voltage regulating units 12 can be connected in parallel, and the output terminals in series. This allows the output voltages to be superimposed, providing the possibility for high-voltage output of the switching power supply circuit. The improved conversion efficiency enables high-power output to meet the high-voltage and high-power requirements of charging pile development. In addition, this application achieves modularity, with relatively small impact between adjacent units, preventing the entire circuit from stopping due to the damage of a single device, thus improving the performance of the charging pile.

[0049] Furthermore, when there are multiple voltage regulating units 12, each voltage regulating unit 12 has the same structure and is connected between the energy storage unit L and the first output terminal P1 and the second output terminal P2 in the same way. Specifically, the output terminals of multiple voltage regulating units 12 are connected in series. It is assumed that the output voltage of each voltage regulating unit 12 can reach 330V, so that the final output voltage is superimposed to reach 1000V.

[0050] Furthermore, the first end of the energy storage unit L is connected to the AC voltage input source A, and the second end is connected to the rectifier bridge unit 11.

[0051] Specifically, the rectifier bridge unit 11 includes an AC input unit and a DC output unit. The AC input unit includes an AC input terminal n1, which is connected to the energy storage unit L. The DC output unit includes a DC output terminal n2, which is connected to the AC voltage input source A. Further, the AC input unit includes a first diode D1 and a third diode D3, and the DC output unit includes a second diode D2 and a fourth diode D4. The anode of the first diode D1 is connected to the AC input terminal n1, the cathode of the third diode D3 is connected to the cathode of the first diode D1, and the anode of the third diode D3 is connected to the DC output terminal n2. The cathode of the second diode D2 is connected to the AC input terminal n1, the anode of the fourth diode D4 is connected to the anode of the second diode D2, and the cathode of the fourth diode D4 is connected to the DC output terminal n2.

[0052] The first and second path terminals of the switching unit Q are connected to the rectifier bridge unit 11 in the corresponding switch control path 10, and the control terminal of the switching unit Q is connected to the peripheral circuit. Specifically, the first path terminal of the switching unit Q is connected to the cathodes of the first diode D1 and the third diode D3, and the second path terminal of the switching unit Q is connected to the anodes of the second diode D2 and the fourth diode D4.

[0053] The voltage regulating unit 12 includes: a first capacitor C1, a transformer T, a second capacitor C2, and a diode B. The first terminal of the first capacitor C1 is connected to the rectifier bridge unit 11, specifically to the first path terminal of the switching unit Q, and the cathodes of a diode D1 and a third diode D3. The first terminal of the primary coil of the transformer T is connected to the second terminal of the first capacitor C1, and the second terminal of the primary coil is connected to the switching unit Q, specifically to the second path terminal of the switching unit Q. The anode of the diode B is connected to the first terminal of the secondary coil of the transformer T. The first terminal of the second capacitor C2 is connected to the cathode of the diode B and the first output terminal P1 of the switching power supply circuit, and the second terminal of the second capacitor C2 is connected to the second terminal of the secondary coil and the second output terminal P2 of the switching power supply circuit. It should be noted that during charging, the first output terminal P1 and the second output terminal P2 are used to connect a load, such as an electric vehicle.

[0054] In one specific embodiment, the voltage regulating unit further includes an inductor M, which is connected in parallel with the primary coil of the transformer. Specifically, one end of the inductor M is connected to the second terminal of the first capacitor C1, and the other end is connected to the second pass terminal of the switching unit.

[0055] In one embodiment, the AC voltage includes a positive-phase AC voltage or a negative-phase AC voltage. In response to the switching unit being turned on, the voltage regulating unit is in the excitation phase, used to store the output voltage; in response to the switching unit being turned off, the voltage regulating unit is in the voltage regulation phase, used to output the regulated output voltage.

[0056] Specifically, in the initial state, switch unit Q is turned on. When an AC voltage is input, if the AC voltage is positive, the first diode D1 and the fourth diode D4 in rectifier bridge unit 11 are turned on, while the third diode D3 and the second diode D2 are turned off. The AC voltage is converted into a DC output voltage by the first diode D1 and the fourth diode D4 in rectifier bridge unit 11 and stored in energy storage unit L. If the AC voltage is negative, the first diode D1 and the fourth diode D4 in rectifier bridge unit 11 are turned off, while the third diode D3 and the second diode D2 are turned on. The AC voltage is converted into a DC output voltage by the third diode D3 and the second diode D2 in rectifier bridge unit 11 and stored in energy storage unit L. It should be noted that when switch unit Q is turned on, the first capacitor C1 and the primary coil of transformer T are essentially connected in parallel. Transformer T is in the excitation stage and is equivalent to an inductor M, which can store the output voltage.

[0057] When the voltage across the energy storage unit L reaches the power supply voltage, the switching unit Q is disconnected. At this time, the first capacitor C1 and the primary coil of the transformer T are essentially in series. The energy storage unit L releases voltage to start charging the first capacitor C1. As time continues, the voltage of the first capacitor C1 continues to increase, and the first capacitor C1 transfers electrical energy to the primary coil of the transformer T. At this time, the voltage regulation unit is in the voltage regulation stage, and the primary coil of the transformer T couples electrical energy to the secondary coil of the transformer T, thereby achieving voltage regulation. The diode B and the second capacitor C2 rectify and filter the voltage signal, reducing the pulsation component in the output voltage, making the rectified voltage smoother, and filtering out the AC component, so that the load terminals (i.e., the first output terminal P1 and the second output terminal P2) receive a DC current with less pulsation, thereby improving the stability of the load during use.

[0058] See Figure 2 , Figure 2 This is a schematic diagram of a second embodiment of the switching power supply circuit provided by this utility model. This embodiment includes three switching control paths: switching control path 10, switching control path 20, and switching control path 30. The three switching control paths are connected in parallel. In this embodiment, each of the three switching control paths is independent, achieving a three-phase input.

[0059] In one embodiment, two of the three switch control paths receive positive phase AC voltages, while the remaining switch control path receives negative phase AC voltages; or, two of the switch control paths receive negative phase AC voltages, while the remaining switch control path receives positive phase AC voltages.

[0060] In this embodiment, the rectifier bridge unit 11 includes an AC input unit and a DC output unit. The AC input unit includes an AC input terminal n1, and the DC output unit includes a DC output terminal n2. The AC input terminal n1 of the rectifier bridge unit 11 in the three switch control paths is connected to the energy storage unit in the corresponding switch control path. Specifically, the AC input terminal n1 of the rectifier bridge unit 11 in switch control path 10 is connected to the energy storage unit L1, the AC input terminal n1 of the rectifier bridge unit 11 in switch control path 20 is connected to the energy storage unit L2, and the AC input terminal n1 of the rectifier bridge unit 11 in switch control path 30 is connected to the energy storage unit L3. The DC output terminals n2 of the rectifier bridge units 11 in the three switch control paths are interconnected.

[0061] In this embodiment, when the AC voltage received by switch control path 10 and switch control path 20 is a positive phase AC voltage, and the AC voltage received by switch control path 30 is a negative phase AC voltage, then AC voltage input sources A and B input a positive phase AC voltage, and AC voltage input source C inputs a negative phase AC voltage. Initially, switch units Q1, Q2, and Q3 are turned on, and diodes D1, D4, D5, D8, D12, and D13 are also turned on. When switch units Q1, Q2, and Q3 are turned on, the AC current of switch control path 10 is converted into a DC output voltage through diodes D1 and D4 and stored in energy storage unit L1. The AC voltage of switch control path 20 is converted into a DC output voltage through diodes D5 and D8 and stored in energy storage unit L2. The AC voltage of switch control path 30 is converted into a DC output voltage through diodes D12 and D13 and stored in energy storage unit L3. During this process, the first capacitor C1 is connected in parallel with the primary coil of transformer T1, and transformer T1 is in the excitation stage. The second capacitor C1 is connected in parallel with the primary coil of transformer T2, and transformer T2 is in the excitation stage. The third capacitor C3 is connected in parallel with the primary coil of transformer T3, and transformer T3 is in the excitation stage. It can be understood that when the transformer is in the excitation stage, it is equivalent to an inductor M, as shown in the diagram, and can store the output voltage.

[0062] When the voltages across energy storage units L1, L2, and L3 reach the power supply voltage, switching units Q1, Q2, and Q3 are disconnected. At this time, the first capacitor C1 and the primary coil of transformer T1 are essentially in series, and energy storage unit L1 releases voltage to charge the first capacitor C1. Similarly, the second capacitor C2 and the primary coil of transformer T2 are in series, and energy storage unit L2 releases voltage to charge the second capacitor C2. Likewise, the third capacitor C3 and the primary coil of transformer T3 are in series, and energy storage unit L3 releases voltage to charge the third capacitor C3. As time continues, the charging voltages of the first capacitor C1, the third capacitor C3, and the fifth capacitor C5 continuously increase, and the voltage of the first capacitor C1 continuously increases. The first capacitor C1 transfers electrical energy to the primary coil of transformer T1. At this time, the voltage regulating unit is in the voltage regulating stage, and the primary coil of transformer T1 couples electrical energy to the secondary coil of transformer T1, thereby achieving voltage regulation. The voltage of the second capacitor C2 continuously increases, transferring electrical energy to the primary coil of transformer T2. At this time, the voltage regulating unit is in the voltage regulating stage, and the primary coil of transformer T2 couples electrical energy to the secondary coil of transformer T2, thereby achieving voltage regulation. The voltage of the third capacitor C3 continuously increases, transferring electrical energy to the primary coil of transformer T3. At this time, the voltage regulating unit is in the voltage regulating stage, and the primary coil of transformer T3 couples electrical energy to the secondary coil of transformer T3, thereby achieving voltage regulation.

[0063] In this system, diode B1 and second capacitor C2, diode B2 and fourth capacitor C4, and diode B3 and sixth capacitor C6 rectify and filter the voltage signal, reducing the pulsating component in the output voltage, making the rectified voltage smoother, and filtering out the AC component, thus ensuring a smooth voltage across the load.

[0064] (i.e., the first output terminal P1 and the second output terminal P2) obtain DC current with smaller ripple to improve the stability when the load is used.

[0065] In this embodiment, when the AC voltage received by switch control path 10 and switch control path 20 is a negative phase AC voltage, and the AC voltage received by switch control path 30 is a positive phase AC voltage, then AC voltage input sources A and B input a negative phase AC voltage, and AC voltage input source C inputs a positive phase AC voltage. Initially, switch units Q1, Q2, and Q3 are turned on, charging energy storage units L1, L2, and L3. Specifically, at this time, the second diode D2, the third diode D3, the seventh diode D7, the sixth diode D6, the eleventh diode D11, and the fourteenth diode D14 are turned on. The remaining processes are the same as described above and will not be repeated here.

[0066] See Figure 3 , Figure 3This is a schematic diagram of the structure of a charging device according to an embodiment of the present invention. In this embodiment, the charging device 100 includes the switching power supply circuit 200 of any of the above embodiments. The charging device 100 can be, for example, a charging pile.

[0067] The above are merely embodiments of this utility model and do not limit the scope of patent protection of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this utility model.

Claims

1. A switching power supply circuit, characterized by comprising: Includes at least one switch control path, said switch control path including: The voltage input unit is connected to an AC voltage input source, receives AC voltage, and outputs DC output voltage based on the AC voltage. A voltage regulating unit, connected in parallel with the voltage input unit and with its output terminal connected to the load, is used to regulate the output voltage and charge the load using the regulated output voltage.

2. The switching power supply circuit according to claim 1, characterized by The voltage input unit is used to perform power factor correction on the AC voltage, thereby generating the output voltage.

3. The switching power supply circuit according to claim 2, characterized in that, The voltage input unit includes: The energy storage unit is connected to the AC voltage input source; A rectifier bridge unit is connected to the AC voltage input source and is connected in series with the energy storage unit; The switching unit is connected in parallel with the rectifier bridge unit; In response to the switching unit being turned on, the AC voltage is converted into the DC output voltage by the rectifier bridge unit, the energy storage unit stores the output voltage, and in response to the switching unit being turned off, the energy storage unit releases the output voltage through the rectifier bridge unit.

4. The switching power supply circuit according to claim 3, characterized in that, When the switching unit is turned on, the voltage regulating unit is in the excitation stage and is used to store the output voltage; when the switching unit is turned off, the voltage regulating unit is in the voltage regulating stage and is used to output the voltage after voltage regulation.

5. The switching power supply circuit according to claim 1, characterized by The voltage regulating unit is multiple, and the multiple voltage regulating units are connected in parallel between the energy storage unit and the load.

6. The switching power supply circuit according to claim 3, characterized by The rectifier bridge unit includes an AC input unit and a DC output unit. The AC input unit includes an AC input terminal connected to the energy storage unit. The DC output unit includes a DC output terminal connected to the AC voltage input source.

7. The switching power supply circuit according to any one of claims 1 to 6, characterized by The AC voltage includes positive phase AC voltage or negative phase AC voltage.

8. The switching power supply circuit according to any one of claims 1 to 6, characterized by The switching power supply circuit includes three switching control paths connected in parallel. Two of the switching control paths receive positive AC voltages, and the remaining one receives a negative AC voltage. Alternatively, two of the switching control paths receive negative AC voltages, and the remaining one receives a positive AC voltage.

9. The switching power supply circuit according to claim 8, characterized in that, The rectifier bridge unit includes an AC input unit and a DC output unit, wherein the AC input unit includes an AC input terminal and the DC output unit includes a DC output terminal; The AC input terminal of the rectifier bridge unit in the three switch control paths is connected to the energy storage unit in the corresponding switch control path, and the DC output terminals of the rectifier bridge units in the three switch control paths are interconnected.

10. The switching power supply circuit according to claim 3, characterized by The first and second path terminals of the switching unit are connected to the rectifier bridge unit in the corresponding switch control path, and the control terminal of the switching unit is connected to the peripheral circuit.

11. The switching power supply circuit according to claim 3, characterized by The voltage regulating unit includes: A first capacitor, the first terminal of which is connected to the rectifier bridge unit; A transformer, wherein a first end of the primary coil of the transformer is connected to a second end of the first capacitor, and the second end of the primary coil is connected to the switching unit; A diode, wherein the anode of the diode is connected to the first terminal of the secondary coil of the transformer; A second capacitor, a first end of the second capacitor is connected to the cathode of the diode and a first output end of the switching power supply circuit, and a second end of the second capacitor is connected to a second end of the secondary coil and a second output end of the switching power supply circuit.

12. The switching power supply circuit according to claim 11, characterized by The voltage regulating unit further comprises: An inductor, the inductor is connected in parallel with the primary coil of the transformer.

13. A charging device, characterized in that, The charging device comprises the switching power supply circuit according to any one of claims 1-12.

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