Circuit, charging equipment and circuit control method

Abstract

The invention discloses a circuit, charging equipment and a control method of the circuit, relates to the technical field of charging equipment, and aims to reduce pre-charging resistance in the charging equipment and reduce cost and power consumption. The circuit comprises an energy storage part and a switch sub-circuit, the energy storage part is electrically connected with the switch sub-circuit; the switch sub-circuit is electrically connected with the power factor correction circuit and / or the direct current conversion circuit; the switch sub-circuit is configured to pre-charge the power factor correction circuit or the DC conversion circuit by using the electric energy stored in the energy storage part; or the electric energy discharged by the power factor correction circuit or the direct current conversion circuit is stored in the energy storage part.

Description

Technical Field

[0001] The present invention relates to the technical field of charging equipment, and in particular to a circuit, a charging device, and a control method for the circuit. Background Art

[0002] With advances in high-power charging technology for electric vehicles, supercharging equipment has been widely adopted in recent years. Supercharging stacks offer high charging power (typically over 600kW), and their power conversion is comprised of multiple internal charging power modules.

[0003] The charging power module consists of two stages. The first stage is the power factor correction module (PFC), which has two functions: one is to realize AC input power factor correction and reduce the electrical harmonics injected by the power module into the AC power grid; the other is to convert the AC power input of the supercharger stack into non-isolated DC power (this DC power is not electrically isolated from the AC power grid and has large ripple, so it cannot directly charge the battery). The second stage is the DC-DC conversion module (DC-DC), which is used to further convert the non-isolated, large-ripple DC power generated by the power factor correction module into isolated, small-fluctuation DC power that can directly charge the battery.

[0004] However, existing technologies require an external pre-charge module to achieve PFC pre-charging. This pre-charge module draws power independently from the AC L / N, which introduces additional AC conduction electromagnetic compatibility issues to the entire supercharging system. Furthermore, the DC-DC module requires the PFC module for pre-charging. Because the PFC module's switches are high-power and numerous, pre-charging the DC-DC module wastes significant energy, further reducing system energy efficiency. Furthermore, after charging is complete, the PFC and DC-DC modules need to discharge energy, which is dissipated through resistors, resulting in significant energy waste. Summary of the Invention

[0005] The object of the present invention is to provide a circuit, a charging device, and a control method for the circuit, aiming to reduce the pre-charging resistance in the charging device, thereby reducing costs and power consumption.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a circuit, comprising: an energy storage unit and a switching sub-circuit; the energy storage unit is electrically connected to the switching sub-circuit; the switching sub-circuit is electrically connected to a power factor correction circuit and / or a DC conversion circuit; the switching sub-circuit is configured to use the electric energy stored in the energy storage unit to pre-charge the power factor correction circuit or the DC conversion circuit; or, to store the electric energy discharged by the power factor correction circuit or the DC conversion circuit in the energy storage unit.

[0008] Based on the above scheme, some embodiments of the present application provide a circuit that pre-charges the power factor correction circuit through an energy storage unit and a switching sub-circuit, and can also pre-charge the DC conversion circuit through the energy storage unit and the switching sub-circuit; the circuit does not require the use of pre-charging resistors, which can further reduce costs, and will not cause electromagnetic compatibility issues, thereby improving energy efficiency. At the same time, the present application actively discharges excess energy through the power factor correction circuit and the DC conversion circuit to transfer excess energy to the energy storage unit for recycling. In this way, it can not only achieve the discharge of electric energy from the power factor correction circuit and the DC conversion circuit, but also save electricity.

[0009] In some embodiments, the switching subcircuit includes: a buck-boost module; the buck-boost module is electrically connected to the energy storage unit, and the buck-boost module is also electrically connected to the power factor correction circuit and / or the DC conversion circuit; the buck-boost module is configured to convert the voltage provided by the energy storage unit to output a target pre-charge voltage to the power factor correction circuit or the DC conversion circuit; or, to convert the voltage discharged by the power factor correction circuit or the DC conversion circuit to output a target discharge voltage to the energy storage unit.

[0010] In some embodiments, the buck-boost module includes: a first switch unit, a second switch unit and an energy storage unit; the first end of the first switch unit is electrically connected to the first end of the buck-boost module, the second end of the first switch unit is electrically connected to the second end of the buck-boost module, and is also electrically connected to the second end of the energy storage unit and the first end of the second switch unit; the third end of the first switch unit is electrically connected to the third end of the buck-boost module, and is also electrically connected to the first end of the energy storage unit; the second end of the second switch unit is electrically connected to the fourth end of the buck-boost module.

[0011] When the first switch unit is turned on and the second switch unit is turned off, the energy storage unit is configured to charge the energy storage unit; after the energy storage unit is charged, the first switch unit is turned off and the second switch unit is turned on, and the energy storage unit is configured to pre-charge the power factor correction circuit or the DC conversion circuit.

[0012] When the first switch unit is turned off and the second switch unit is turned on, the power factor correction circuit or the DC conversion circuit discharges electric energy to charge the energy storage unit; after the energy storage unit is charged, the first switch unit is turned on and the second switch unit is turned off, and the energy storage unit is configured to charge the energy storage part.

[0013] In some embodiments, the first switch unit includes: a first capacitor and a first switch tube; the first end of the first capacitor is electrically connected to the first end of the first switch unit and is also electrically connected to the first end of the first switch tube, the second end of the first capacitor is electrically connected to the second end of the first switch unit; the second end of the first switch tube is electrically connected to the third end of the first switch unit.

[0014] In some embodiments, the second switch unit includes: a second switch tube; a first end of the second switch tube is electrically connected to the first end of the second switch unit, and a second end of the second switch tube is electrically connected to the second end of the second switch unit. The energy storage unit includes a first inductor; a first end of the first inductor is electrically connected to the first end of the energy storage unit, and a second end of the first inductor is electrically connected to the second end of the energy storage unit.

[0015] In some embodiments, the switching subcircuit further includes: a switching module; the switching module is electrically connected to the buck-boost module; the switching module is electrically connected to the power factor correction circuit and / or the DC conversion circuit; the switching module is configured to electrically connect the buck-boost module to the power factor correction circuit to pre-charge or discharge electric energy of the power factor correction circuit; or, to electrically connect the buck-boost module to the DC conversion circuit to pre-charge or discharge electric energy of the DC conversion circuit.

[0016] In some embodiments, the switching module includes: a first switching device and a second switching device; the first end of the first switching device is electrically connected to the second end of the switching module, the second end of the first switching device is electrically connected to the third end of the switching module, and the third end of the first switching device is electrically connected to the fifth end of the switching module; the first end of the second switching device is electrically connected to the first end of the switching module, the second end of the second switching device is electrically connected to the fourth end of the switching module, and the third end of the second switching device is electrically connected to the sixth end of the switching module.

[0017] In some embodiments, the third end of the switching module is electrically connected to the first end of the power factor correction circuit, and the fourth end of the switching module is electrically connected to the second end of the power factor correction circuit; the fifth end of the switching module is electrically connected to the first end of the DC conversion circuit, and the sixth end of the switching module is electrically connected to the second end of the DC conversion circuit (120).

[0018] In some embodiments, the pre-charge and discharge sub-circuit further includes: a control sub-circuit electrically connected to the first switching device and the second switching device; the control sub-circuit is configured to control the first end and the second end of the first switching device to be conductive, and to control the first end and the second end of the second switching device to be conductive, so as to pre-charge or discharge the power factor correction circuit; or, to control the first end and the third end of the first switching device to be conductive, and to control the first end and the third end of the second switching device to be conductive, so as to pre-charge or discharge the DC conversion circuit.

[0019] In some embodiments, the buck-boost module further includes: a second capacitor; a first end of the second capacitor is electrically connected to the first end of the energy storage unit, and a second end of the second capacitor is electrically connected to the second end of the second switch unit.

[0020] In some embodiments, the energy storage portion includes a photovoltaic cell.

[0021] In a second aspect, the present application provides a charging device, comprising: a circuit, a power factor correction circuit and a DC conversion circuit, wherein the first end of the power factor correction circuit is electrically connected to the first end of the circuit, and the second end of the power factor correction circuit is electrically connected to the second end of the circuit; the first end of the DC conversion circuit is electrically connected to the third end of the circuit, and the second end of the DC conversion circuit is electrically connected to the fourth end of the circuit.

[0022] Among them, the beneficial effects of the second aspect and its possible embodiments can refer to the first aspect and will not be repeated here.

[0023] In some embodiments, the power factor correction circuit includes: a third capacitor; the first end of the third capacitor is electrically connected to the first end of the power factor correction circuit, and the second end of the third capacitor is electrically connected to the second end of the power factor correction circuit; the DC conversion circuit includes: a fourth capacitor; the first end of the fourth capacitor is electrically connected to the first end of the DC conversion circuit, and the second end of the fourth capacitor is electrically connected to the second end of the DC conversion circuit.

[0024] In a third aspect, the present application provides a control method applied to the above-mentioned circuit.

[0025] Control the switch subcircuit and the power factor correction circuit to conduct forward or reverse, so as to pre-charge the power factor correction circuit or discharge electric energy; or control the switch subcircuit and the DC conversion circuit to conduct forward or reverse, so as to pre-charge the DC conversion circuit or discharge electric energy.

[0026] Among them, the beneficial effects of the third aspect and its possible embodiments can refer to the first aspect and will not be repeated here.

[0027] In some embodiments, the switching subcircuit includes a first switching device and a second switching device.

[0028] Controlling the switch subcircuit and the power factor correction circuit to conduct forward or reverse includes: controlling the first end and the second end of the first switch device to conduct, and controlling the first end and the second end of the second switch device to conduct, so as to pre-charge the power factor correction circuit or discharge electric energy.

[0029] Controlling the switch subcircuit and the DC conversion circuit to conduct forward or reverse includes: controlling the first end and the third end of the first switching device to conduct, and controlling the first end and the third end of the second switching device to conduct, so as to pre-charge the DC conversion circuit or discharge electric energy.

[0030] In some embodiments, the switch sub-circuit includes: a first capacitor, a first switch tube, a second switch tube, and a first inductor.

[0031] Controlling the switch subcircuit and the power factor correction circuit or the DC conversion circuit to be forward-conducted includes: in a first stage, controlling the first switch tube to be turned on and the second switch tube to be turned off; the energy storage unit charges the first inductor through the first capacitor; in a second stage, controlling the first switch tube to be turned off and the second switch tube to be turned on; the first inductor pre-charges the power factor correction circuit or the DC conversion circuit.

[0032] In some embodiments, in the process of controlling the switch sub-circuit and the power factor correction circuit or the DC conversion circuit to be forward-conducted, the first switch tube is controlled to operate at a first set switching frequency and a first duty cycle.

[0033] In some embodiments, before controlling the forward conduction of the switch sub-circuit and the power factor correction circuit or the DC conversion circuit, it also includes: receiving pre-charge information, the pre-charge information includes a target pre-charge voltage and a pre-charge time; the first set switching frequency and the first duty cycle are determined according to the pre-charge information.

[0034] In some embodiments, the switch sub-circuit includes: a first capacitor, a first switch tube, a second switch tube, and a first inductor.

[0035] Controlling the switch subcircuit and the power factor correction circuit or the DC conversion circuit to reverse conduction includes: in the first stage, controlling the first switch tube to be cut off and the second switch tube to be turned on; the power factor correction circuit or the DC conversion circuit charges the first inductor.

[0036] In the second stage, the first switch tube is controlled to be turned on and the second switch tube is turned off; the first inductor charges the energy storage part through the first capacitor.

[0037] In some embodiments, in the process of controlling the switch sub-circuit and the power factor correction circuit or the DC conversion circuit to reverse conduct, the second switch tube is controlled to operate at a second set switching frequency and a second duty cycle.

[0038] In some embodiments, before controlling the switch sub-circuit and the power factor correction circuit or the DC conversion circuit to reverse conduct, the method further includes: receiving power discharge information, the power discharge information including a target discharge voltage and a discharge time; and determining the second set switching frequency and the second duty cycle based on the power discharge information.

[0039] In some embodiments, before controlling the switch sub-circuit and the power factor correction circuit to be forward-conducted, the method further includes: receiving a first pre-charge instruction, where the first pre-charge instruction is used to instruct the circuit to pre-charge the power factor correction circuit.

[0040] Before controlling the switch sub-circuit and the power factor correction circuit to conduct in reverse, the method further includes: receiving a first discharge instruction, where the first discharge instruction is used to instruct the circuit to discharge electric energy to the power factor correction circuit.

[0041] Before controlling the switch sub-circuit and the DC conversion circuit to be forward-conducted, the method further includes: receiving a second pre-charging instruction, where the second pre-charging instruction is used to instruct the circuit to pre-charge the DC conversion circuit.

[0042] Before controlling the switch sub-circuit and the DC conversion circuit to be reversely conductive, the method further includes: receiving a second discharge instruction, where the second discharge instruction is used to instruct the circuit to discharge electric energy from the DC conversion circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 A schematic diagram of an existing charging device provided in an embodiment of the present application;

[0045] Figure 2 A schematic diagram of an existing PFC module provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of another existing PFC module provided in an embodiment of the present application;

[0047] Figure 4 A schematic diagram of an existing DC module provided in an embodiment of the present application;

[0048] Figure 5 A schematic diagram of a circuit provided in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of another circuit provided in an embodiment of the present application;

[0050] Figure 7 A schematic diagram of another circuit provided in an embodiment of the present application;

[0051] Figure 8 A flow chart of pre-charging a power factor correction circuit provided in an embodiment of the present application;

[0052] Figure 9 A flow chart of precharging a DC conversion circuit provided in an embodiment of the present application;

[0053] Figure 10 A flow chart of power energy discharge of a power factor correction circuit provided in an embodiment of the present application;

[0054] Figure 11 A flow chart of electric energy discharge of a DC conversion circuit provided in an embodiment of the present application;

[0055] Figure 12 A schematic diagram of a charging device provided in an embodiment of the present application.

[0056] Reference numerals: 1, energy storage unit; 2, switch subcircuit; 3, control subcircuit; 21, buck-boost module; 22, switching module; 23, first switch unit; 24, second switch unit; 25, energy storage unit; 100, circuit; 110, power factor correction circuit; 120, DC converter circuit; 200, charging device. C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; Q1, first switch; Q2, second switch; L1, first inductor; SW1, first switch; SW2, second switch. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] In the description of the invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "back," "inner," "outer," and the like, indicating directions or positional relationships, are based on the directions or relative positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limitations on the invention. Unless otherwise specified, the above-mentioned directions may be flexibly set in actual application, provided that the relative positional relationships shown in the accompanying drawings are met.

[0059] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0060] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "communicated" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections. They may be directly connected, indirectly connected through an intermediary, or internally connected between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0061] In embodiments of the present invention, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of other identical elements in the process, article, or apparatus comprising the element.

[0062] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0063] With the advancement of high-power charging technology for electric vehicles, super charging equipment has been widely promoted and applied in recent years. The super charging stack has a large charging power (generally above 600kW), and its power conversion is composed of multiple internal charging power modules (refer to Figure 1 ).

[0064] The charging power module consists of two stages. The first stage is the power factor correction module (PFC), which has two functions: one is to realize AC input power factor correction and reduce the electrical harmonics injected by the power module into the AC power grid; the other is to convert the AC power input of the supercharger stack into non-isolated DC power (this DC power is not electrically isolated from the AC power grid and has large ripple, so it cannot directly charge the battery). The second stage is the DC-DC conversion module (DC-DC), which is used to further convert the non-isolated, large-ripple DC power generated by the power factor correction module into isolated, small-fluctuation DC power that can directly charge the battery.

[0065] However, existing technologies require an external pre-charge module to achieve PFC pre-charging. This pre-charge module draws power independently from the AC L / N, which introduces additional AC conduction electromagnetic compatibility issues to the entire supercharging system. Furthermore, the DC-DC module requires the PFC module for pre-charging. Because the PFC module's switches are high-power and numerous, pre-charging the DC-DC module wastes significant energy, further reducing system energy efficiency. Furthermore, after charging is complete, the PFC and DC-DC modules need to discharge energy, which is dissipated through resistors, resulting in significant energy waste.

[0066] For the convenience of explanation, the DC-DC module will be referred to as DC module below.

[0067] For example, due to the high power consumption of supercharging modules, their PFC and DC modules are typically designed separately, forming independent PFC and DC modules. A supercharging stack utilizes multiple PFC modules connected in parallel to form the PFC stage, and multiple DC modules connected in parallel to form the DC stage. The output of the PFC stage serves as the input for the DC stage, and the output of the DC stage can directly charge the power battery. The PFC stage output voltage is called the bus voltage or PFC-bus, while the DC output voltage is called high-voltage DC or HVDC.

[0068] Reference Figure 2 The PFC module is connected to the AC power supply via a relay. The PFC module output side typically has large-capacity capacitors. If these capacitors are not pre-charged when the AC power is applied, the large-capacity capacitors will cause a momentary short circuit when the AC relay closes, generating a large inrush current. In severe cases, this can damage components in the circuit, such as MOSFETs. To achieve pre-charging, traditional PFC circuits connect a resistor in parallel across the contacts of each AC input relay to eliminate the startup inrush current. This resistor is called a pre-charge resistor. After the large-capacity capacitors are pre-charged, the AC input relay is closed. Traditional PFC modules use pre-charge resistors to pre-charge the PFC-BUS voltage.

[0069] The supercharger system has high power, and the PFC module has large output capacitors. When the supercharger is powered by AC but the supercharger output is not charging the vehicle or battery (this state is called standby), the relay is closed, and the AC power forms an electrical connection with the PFC circuit. This creates a large circulating current within the PFC module, resulting in high standby losses. To reduce the supercharger's standby losses, it is necessary to disconnect the AC relay and the pre-charge resistor in standby mode, completely severing the pre-charge circuit to reduce standby losses.

[0070] Reference Figure 3, the PFC circuit must have a pre-charge function. When the pre-charge resistor is cancelled, a new PFC pre-charge circuit needs to be designed. In the prior art, a controlled low-power power supply (usually hundreds of watts) is placed outside the PFC module of the supercharge stack to realize the pre-charge of the PFC module. The external PFC pre-charge module (hereinafter referred to as the pre-charge module in the accompanying drawings) is input from the single-phase AC power L / N. After the PFC issues a power-on command, the output voltage of the pre-charge module rises to the uncontrolled rectifier voltage VBUS_0 of the supercharge stack PFC module. Then the supercharge stack PFC module closes the AC input relay to achieve zero voltage closure of the AC input relay.

[0071] Reference Figures 2 to 4 The PFC module of the supercharger stack has a large-capacity capacitor on its output side. After the supercharger stack stops charging, a dummy load on the PFC output side (a resistor connected in parallel across the large-capacity capacitor) is generally used to enhance circuit control stability during normal charging. After charging stops, the residual voltage of the large-capacity capacitor is discharged, which is called a passive discharge resistor.

[0072] Reference Figure 4 At the same time, the charging standard requires that the DC module of the supercharging stack have an active discharge function. That is, after the supercharging system stops charging, the DC module needs to discharge the residual high voltage at its output end to within the specified voltage value within the specified time to ensure electrical safety. The competing solution connects a switching tube and a discharge resistor in parallel at the output capacitor of each DC module. When the system is charging, the switching tube is disconnected, and the discharge resistor is disconnected from the HVDC circuit, and no loss is generated; when the system stops charging and enters the active discharge process, the switching tube is closed, and the discharge resistor is connected in parallel to the DC module output capacitor, consuming the electrical energy of the output capacitor and discharging the residual voltage of the output capacitor to the specified safety voltage value.

[0073] Based on this, an embodiment of the present application provides a circuit. For example, Figure 5 As shown, the circuit 100 includes: an energy storage unit 1 and a switch sub-circuit 2.

[0074] The energy storage unit 1 is electrically connected to the switch sub-circuit 2 .

[0075] The switch sub-circuit 2 is electrically connected to the power factor correction circuit 110 and / or the DC conversion circuit 120 .

[0076] The switch subcircuit 2 is configured to use the electric energy stored in the energy storage unit 1 to pre-charge the power factor correction circuit 110 or the DC conversion circuit 120; or to store the electric energy discharged by the power factor correction circuit 110 or the DC conversion circuit 120 in the energy storage unit 1.

[0077] In some embodiments, the energy storage unit 1 includes a photovoltaic cell.

[0078] The switch sub-circuit 2 may be electrically connected only to the power factor correction circuit 110 , or only to the DC conversion circuit 120 , or to both the power factor correction circuit 110 and the DC conversion circuit 120 .

[0079] That is to say, the electric energy is first stored in the energy storage unit 1, and the energy storage unit 1 transmits the stored electric energy to the switch sub-circuit 2, and the switch sub-circuit 2 then transmits the electric energy to the power factor correction circuit 110 or the DC conversion circuit 120 to pre-charge the power factor correction circuit 110 or the DC conversion circuit 120.

[0080] At the same time, after the power factor correction circuit 110 completes charging or completes work, it will actively discharge. At this time, the power factor correction circuit 110 stores the discharged electric energy in the energy storage part 1 for use during the next pre-charging. Similarly, after the DC conversion circuit 120 completes charging or completes work, it will actively discharge. At this time, the DC conversion circuit 120 stores the discharged electric energy in the energy storage part 1 for use during the next pre-charging.

[0081] It should be noted that pre-charging refers to the circuit pre-charging the output of the power supply (PFC output, or DC output) in order to achieve faster output voltage slow start and reduce input inrush current.

[0082] Based on the above scheme, some embodiments of the present application provide a circuit that pre-charges the power factor correction circuit through an energy storage unit and a switching sub-circuit, and can also pre-charge the DC conversion circuit through the energy storage unit and the switching sub-circuit; the circuit does not require the use of pre-charging resistors, which can further reduce costs, and will not cause electromagnetic compatibility issues, thereby improving energy efficiency. At the same time, the present application actively discharges excess energy through the power factor correction circuit and the DC conversion circuit to transfer excess energy to the energy storage unit for recycling. In this way, it can not only achieve the discharge of electric energy from the power factor correction circuit and the DC conversion circuit, but also save electricity.

[0083] like Figure 6 As shown, the switch sub-circuit 2 includes a buck-boost module 21 and a switching module 22 .

[0084] The buck-boost module 21 is electrically connected to the energy storage unit 1 , and is also electrically connected to the switching module 22 .

[0085] The switching module 22 is electrically connected to the power factor correction circuit 110 and / or the DC conversion circuit 120 .

[0086] That is to say, the switching module 22 can be electrically connected only to the power factor correction circuit 110 , or only to the DC conversion circuit 120 , or to both the power factor correction circuit 110 and the DC conversion circuit 120 .

[0087] The buck-boost module 21 is configured to transform the voltage provided by the energy storage unit 1 to output a target pre-charge voltage to the power factor correction circuit 110 or the DC conversion circuit 120; or, to transform the voltage discharged by the power factor correction circuit 110 or the DC conversion circuit 120 to output a target discharge voltage to the energy storage unit 1.

[0088] The switching module 22 is configured to electrically connect the buck-boost module 21 to the power factor correction circuit 110 to pre-charge or discharge the power factor correction circuit 110; or, to electrically connect the buck-boost module 21 to the DC conversion circuit 120 to pre-charge or discharge the DC conversion circuit 120.

[0089] That is to say, electric energy is first stored through the energy storage part 1, and the energy storage part 1 transmits the stored electric energy to the buck-boost module 21. When the switching module 22 connects the buck-boost module 21 with the power factor correction circuit 110, the buck-boost module 21 converts the voltage provided by the energy storage part 1, and then transmits the electric energy to the power factor correction circuit 110 to pre-charge the power factor correction circuit 110; when the switching module 22 connects the buck-boost module 21 with the DC conversion circuit 120, the buck-boost module 21 converts the voltage provided by the energy storage part 1, and then transmits the electric energy to the DC conversion circuit 120 to pre-charge the DC conversion circuit 120.

[0090] At the same time, after the power factor correction circuit 110 completes charging or working, it will actively discharge. At this time, the switching module 22 connects the buck-boost module 21 with the power factor correction circuit 110, and the power factor correction circuit 110 stores the discharged electric energy in the energy storage part 1 through the buck-boost module 21 for use during the next pre-charging.

[0091] Similarly, after the DC conversion circuit 120 completes charging or working, it will actively discharge. At this time, the switching module 22 connects the buck-boost module 21 with the DC conversion circuit 120, and the DC conversion circuit 120 stores the discharged electric energy in the energy storage part 1 through the buck-boost module 21 so that it can be used during the next pre-charging.

[0092] like Figure 7 As shown, the buck-boost module 21 includes a first switch unit 23 , a second switch unit 24 and an energy storage unit 25 .

[0093] The first end 231 of the first switch unit 23 is electrically connected to the first end 211 of the buck-boost module 21, the second end 232 of the first switch unit 23 is electrically connected to the second end 212 of the buck-boost module 21, and is also electrically connected to the second end 252 of the energy storage unit 25 and the first end 241 of the second switch unit 24; the third end 233 of the first switch unit 23 is electrically connected to the third end 213 of the buck-boost module 21, and is also electrically connected to the first end of the energy storage unit 25; the fourth end 214 of the buck-boost module 21 is electrically connected to the second end 242 of the second switch unit 24.

[0094] When the first switch unit 23 is turned on and the second switch unit 24 is turned off, the energy storage unit 1 is configured to charge the energy storage unit 25; after the energy storage unit is charged, the first switch unit 23 is turned off and the second switch unit is turned on, and the energy storage unit 25 is configured to pre-charge the power factor correction circuit 110 or the DC conversion circuit 120.

[0095] When the first switch unit 23 is turned off and the second switch unit 24 is turned on, the power factor correction circuit 110 or the DC conversion circuit 120 discharges electric energy to charge the energy storage unit 25; after the energy storage unit 25 is charged, the first switch unit 23 is turned on and the second switch unit is turned off, and the energy storage unit 25 is configured to charge the energy storage part 1.

[0096] That is to say, when the energy storage part 1 pre-charges the power factor correction circuit 110 or the DC conversion circuit 120, the first switch unit 23 is first turned on to charge the energy storage unit 25. After the energy storage unit 25 is completely charged, the first switch unit 23 is turned off, and then the second switch unit 24 is turned on; the switching module 22 connects the buck-boost module 21 with the power factor correction circuit 110, and the energy storage unit 25 pre-charges the power factor correction circuit 110; the switching module 22 connects the buck-boost module 21 with the DC conversion circuit 120, and the energy storage unit 25 pre-charges the DC conversion circuit 120.

[0097] When the power factor correction circuit 110 or the DC conversion circuit 120 discharges electric energy, the second switch unit 24 is first turned on to charge the energy storage unit 25. After the energy storage unit 25 is completely charged, the second switch unit 24 is turned off and the first switch unit 23 is turned on again; the energy storage unit 25 charges the energy storage part.

[0098] like Figure 7 As shown, the first switch unit 23 includes: a first capacitor C1 and a first switch tube Q1.

[0099] The first end of the first capacitor C1 is electrically connected to the first end 231 of the first switch unit 23, and is also electrically connected to the first end of the first switch tube Q1. The second end of the first capacitor C1 is electrically connected to the second end 232 of the first switch unit 23; the second end of the first switch tube Q1 is electrically connected to the third end 233 of the first switch unit 23.

[0100] In some embodiments, the first switch transistor Q1 is a MOS transistor.

[0101] The energy storage part 1 may first store the electric energy in the first capacitor C1 , and after the first switch tube is turned on, the first capacitor C1 stores the electric energy in the energy storage unit 25 .

[0102] The second switch unit 24 includes a second switch tube Q2 .

[0103] A first end of the second switch tube Q2 is electrically connected to the first end 241 of the second switch unit 24 , and a second end of the second switch tube Q2 is electrically connected to the second end 242 of the second switch unit 24 .

[0104] The energy storage unit 25 includes a first inductor L1 .

[0105] A first end of the first inductor L1 is electrically connected to the first end 251 of the energy storage unit 25 , and a second end of the first inductor L1 is electrically connected to the second end 252 of the energy storage unit 25 .

[0106] Reference Figure 7 The switching module 22 includes: a first switching device SW1 and a second switching device SW2.

[0107] The first terminal S11 of the first switch device SW1 is electrically connected to the second terminal 222 of the switching module 22, the second terminal S12 of the first switch device SW1 is electrically connected to the third terminal 223 of the switching module 22, and the third terminal S13 of the first switch device SW1 is electrically connected to the fifth terminal 225 of the switching module 22.

[0108] The first end S21 of the second switch device SW2 is electrically connected to the first end 221 of the switching module 22, the second end S22 of the second switch device SW2 is electrically connected to the fourth end 224 of the switching module 22, and the third end S23 of the second switch device SW2 is electrically connected to the sixth end 226 of the switching module 22.

[0109] The pre-charge and discharge sub-circuit 100 further includes: a control sub-circuit 3 .

[0110] The control sub-circuit 3 is electrically connected to the first switching device SW1 and the second switching device SW2 .

[0111] The control subcircuit 3 is configured to control the first terminal S11 and the second terminal S12 of the first switching device SW1 to be conductive, and to control the first terminal S21 and the second terminal S22 of the second switching device SW2 to be conductive, so as to pre-charge or discharge the power factor correction circuit 110; or to control the first terminal S11 and the third terminal S13 of the first switching device SW1 to be conductive, and to control the first terminal S21 and the third terminal S23 of the second switching device SW2 to be conductive, so as to pre-charge or discharge the DC conversion circuit 120.

[0112] For example, when the energy storage part 1 pre-charges the power factor correction circuit 110 or the DC conversion circuit 120, the energy storage part 1 first charges the first capacitor C1, then turns on the first switch unit 23, and charges the energy storage unit 25 through the first capacitor C1. After the energy storage unit 25 is completely charged, the first switch unit 23 is turned off, and then the second switch unit 24 is turned on; the control sub-circuit 3 controls the first end S11 and the second end S12 of the first switch device SW1 to be turned on, and controls the first end S21 and the second end S22 of the second switch device SW2 to be turned on, and the energy storage unit 25 pre-charges the power factor correction circuit 110; the control sub-circuit 3 controls the first end S11 and the third end S13 of the first switch device SW1 to be turned on, and controls the first end S21 and the third end S23 of the second switch device SW2 to be turned on, and the energy storage unit 25 pre-charges the DC conversion circuit 120.

[0113] When the power factor correction circuit 110 or the DC conversion circuit 120 discharges electric energy, the second switch unit 24 is first turned on to charge the energy storage unit 25. After the energy storage unit 25 is completely charged, the second switch unit 24 is turned off and the first switch unit 23 is turned on again; the energy storage unit 25 charges the energy storage part 1, thereby completing the discharge and storage of electric energy.

[0114] That is to say, the third end 223 of the switching module 22 is electrically connected to the first end A1 of the power factor correction circuit 110, and the fourth end 224 of the switching module 22 is electrically connected to the second end A2 of the power factor correction circuit 110; the fifth end 225 of the switching module 22 is electrically connected to the first end B1 of the DC conversion circuit 120, and the sixth end 226 of the switching module 22 is electrically connected to the second end B2 of the DC conversion circuit 120.

[0115] In some embodiments, the control sub-circuit 3 is further electrically connected to the control end of the first switch tube Q1 and the control end of the second switch tube Q2.

[0116] Among them, the control end refers to the gate of the MOS tube.

[0117] The control sub-circuit 3 is further configured to control the on and off of the first switch tube Q1 and the second switch tube Q2.

[0118] For example, when the buck-boost module is working in the forward direction, the first switch Q1 and the second switch Q2 operate at a fixed switching frequency f with a period of T. The on-time of the first switch Q1 is D1*T, where D1 is called the duty cycle.

[0119]

[0120] When the first switch Q1 is turned on, the first inductor L1 stores energy under the excitation of the first voltage V1. The inductor voltage of the first inductor L1 is positive at the top and negative at the bottom. The change in the inductor current of the first inductor L1 satisfies:

[0121]

[0122] The first voltage V1 refers to the voltage across the first capacitor C1.

[0123] When the first switch tube Q1 is turned off and the second switch tube Q2 is turned on, the first inductor L1 releases energy. The voltage across the first inductor L1 is V2. The inductor voltage of the first inductor L1 is positive at the bottom and negative at the top. The energy release time of the first inductor is: T*(1-D1). The change in the current of the first inductor satisfies:

[0124]

[0125] Wherein, L1 in the formula refers to the inductance value of the first inductor.

[0126] After steady state, the circuit satisfies:

[0127] ΔI_1=ΔI_2 (4)

[0128] By combining formulas (2)-(3)-(4), we can find the formula for the output voltage V2 of the buck-boost module with respect to V1 when working in the forward direction:

[0129]

[0130] It can be seen from formula (5) that when D1>0.5, V2>V1, the circuit achieves voltage boost; when D1<0.5, V2<V1, the circuit achieves voltage reduction; when D=0.5, V2=V1.

[0131] Similarly, when the buck-boost module 21 works in reverse, the first switch Q1 and the second switch Q2 work at a fixed switching frequency f with a period of T. The on-time of the second switch Q2 is D2*T, where D2 is the duty cycle of the second switch Q2.

[0132] When the second switch Q2 is turned on, the first inductor L1 stores energy under the stimulation of the second voltage V2, and the change in the inductor current satisfies:

[0133]

[0134] When the second switch tube Q2 is turned off and the first switch tube Q1 is turned on, the first inductor L1 releases energy. The voltage across the first inductor L1 is V1. The energy release time is: T*(1-D2). The change in the current of the first inductor satisfies:

[0135]

[0136] Wherein, L1 in the formula refers to the inductance value of the first inductor.

[0137] After steady state, the circuit satisfies:

[0138] ΔI_3=ΔI_4 (8)

[0139] By combining formulas (6)-(7)-(8), we can find the formula for the output voltage V1 of the buck-boost module relative to V2 when working in reverse:

[0140]

[0141] It can be seen from formula (9) that when D2>0.5, V1>V2, the circuit achieves voltage boost; when D2<0.5, V1<V2, the circuit achieves voltage reduction; when D=0.5, V1=V2.

[0142] The above describes the forward and reverse operation of the buck-boost module. Forward operation refers to the energy storage unit 1 pre-charging the power factor correction circuit 110 and the DC conversion circuit 120 through the buck-boost module 21; reverse operation refers to the power factor correction circuit 110 and the DC conversion circuit 120 charging the energy storage unit 1 through the buck-boost module 21.

[0143] In other words, the buck-boost module is a two-terminal switching power supply circuit, with one end voltage being V1 and the other end voltage being V2. It can be divided into two working conditions:

[0144] When operating in the forward direction, the input voltage is V1 (the first voltage mentioned above) and the output voltage is V2 (the second voltage mentioned above). In this case, the circuit gain is defined as follows:

[0145]

[0146] The buck-boost module outputs a target voltage of V2. At this time, the buck-boost module needs to satisfy the requirement that the gain K1 can be less than or equal to 1 or greater than 1 through control methods (including but not limited to variable duty cycle, variable frequency, etc.), that is, it can output both boost and buck.

[0147] When working in reverse, the input voltage is V2 and the output voltage is V1. At this time, the circuit gain is defined as follows:

[0148]

[0149] The buck-boost module outputs a target voltage of V1. At this time, the buck-boost module needs to satisfy the requirement that the gain K2 can be less than or equal to 1 or greater than 1 through control methods (including but not limited to variable duty cycle, variable frequency, etc.), that is, it can output both boost and buck.

[0150] In some embodiments, the buck-boost module 21 further includes a second capacitor C2.

[0151] A first end of the second capacitor C2 is electrically connected to a first end of the energy storage unit 25 , and a second end of the second capacitor C2 is electrically connected to a second end of the second switch unit 24 .

[0152] The second capacitor C2 plays a filtering role.

[0153] like Figures 8 to 11 As shown, Figures 8 to 11 The flow chart of the circuit control method is as follows:

[0154] Reference Figure 8 , Figure 8 Flowchart for precharging a power factor correction circuit.

[0155] S101: A control subcircuit receives a first pre-charge instruction and pre-charge information.

[0156] The first pre-charge instruction is used to instruct the circuit to pre-charge the power factor correction circuit. The pre-charge information includes a target pre-charge voltage and a pre-charge time.

[0157] S102 , controlling the switch sub-circuit and the power factor correction circuit to conduct forward.

[0158] S103 , the control sub-circuit controls the first terminal and the second terminal of the first switching device to be conductive, and controls the first terminal and the second terminal of the second switching device to be conductive.

[0159] S104 , controlling the first switch tube to be turned on and the second switch tube to be turned off.

[0160] The first switch operates at a first set switching frequency and a first duty cycle. The first set switching frequency and the first duty cycle are determined based on pre-charge information. For details, see Formulas (2) to (5).

[0161] S105 : The energy storage unit charges the first inductor through the first capacitor.

[0162] S106 , controlling the first switch tube to be turned off and the second switch tube to be turned on.

[0163] S107 , the first inductor pre-charges the power factor correction circuit.

[0164] Reference Figure 9 , Figure 9 Flowchart for precharging the DC conversion circuit.

[0165] S201: The control sub-circuit receives a second pre-charge instruction and pre-charge information.

[0166] The second pre-charge instruction is used to instruct the circuit to pre-charge the DC conversion circuit. The pre-charge information includes a target pre-charge voltage and a pre-charge time.

[0167] S202 , controlling the switch sub-circuit and the DC conversion circuit to conduct forward.

[0168] S203 , controlling the first terminal and the third terminal of the first switching device to be conductive, and controlling the first terminal and the third terminal of the second switching device to be conductive.

[0169] S204 , controlling the first switch tube to be turned on and the second switch tube to be turned off.

[0170] The first switch operates at a first set switching frequency and a first duty cycle. The first set switching frequency and the first duty cycle are determined based on pre-charge information. For details, see Formulas (2) to (5).

[0171] S205 : The energy storage unit charges the first inductor through the first capacitor.

[0172] S206 , controlling the first switch tube to be turned off and the second switch tube to be turned on.

[0173] S207 : The first inductor pre-charges the DC conversion circuit.

[0174] Reference Figure 10 , Figure 10 This is a flow chart of power factor correction circuit energy discharge.

[0175] S301: A control subcircuit receives a first discharge instruction and electric energy discharge information.

[0176] The first discharge instruction is used to instruct the circuit to discharge electric energy from the power factor correction circuit. The electric energy discharge information includes a target discharge voltage and a discharge time.

[0177] S302 , controlling the switch sub-circuit and the power factor correction circuit to conduct in reverse.

[0178] S303 , the control sub-circuit controls the first terminal and the second terminal of the first switching device to be conductive, and controls the first terminal and the second terminal of the second switching device to be conductive.

[0179] S304 , controlling the first switch tube to be turned off and the second switch tube to be turned on.

[0180] The second switching tube operates at a second set switching frequency and a second duty cycle. The second set switching frequency and the second duty cycle are determined based on the power discharge information. For details, please refer to formulas (6) to (9).

[0181] S305: The power factor correction circuit charges the first inductor.

[0182] S306 , controlling the first switch tube to be turned on and the second switch tube to be turned off.

[0183] S307 : The first inductor charges the energy storage unit through the first capacitor.

[0184] Reference Figure 11 , Figure 11 This is a flow chart of the energy discharge of the DC conversion circuit.

[0185] S401: The control sub-circuit receives a second discharge instruction and electric energy discharge information.

[0186] The second discharge instruction is used to instruct the circuit to discharge electric energy from the DC conversion circuit. The electric energy discharge information includes a target discharge voltage and a discharge time.

[0187] S402 , controlling the switch sub-circuit and the DC conversion circuit to conduct in reverse.

[0188] S403 , controlling the first terminal and the third terminal of the first switching device to be conductive, and controlling the first terminal and the third terminal of the second switching device to be conductive.

[0189] S404 , controlling the first switch tube to be turned off and the second switch tube to be turned on.

[0190] The second switching tube operates at a second set switching frequency and a second duty cycle. The second set switching frequency and the second duty cycle are determined based on the power discharge information. For details, please refer to formulas (6) to (9).

[0191] S405 : The DC conversion circuit charges the first inductor.

[0192] S406 , controlling the first switch tube to be turned on and the second switch tube to be turned off.

[0193] S407 : The first inductor charges the energy storage unit through the first capacitor.

[0194] This application also provides a charging device, such as Figure 12 As shown, the charging device 200 includes: a circuit 100 , a power factor correction circuit 110 and a DC conversion circuit 120 .

[0195] A first terminal A1 of the power factor correction circuit 110 is electrically connected to a first terminal X1 of the circuit 100 , and a second terminal A2 of the power factor correction circuit 110 is electrically connected to a second terminal X2 of the circuit 100 .

[0196] The first terminal B1 of the DC conversion circuit 120 is electrically connected to the third terminal X3 of the circuit 100 , and the second terminal B2 of the DC conversion circuit 120 is electrically connected to the fourth terminal X4 of the circuit 100 .

[0197] In some embodiments, the charging device may be a charging stack or a charging post.

[0198] In some embodiments, the power factor correction circuit 110 includes a third capacitor C3 .

[0199] A first end of the third capacitor C3 is electrically connected to a first end of the power factor correction circuit 110 , and a second end of the third capacitor C3 is electrically connected to a second end of the power factor correction circuit 110 .

[0200] The DC conversion circuit 120 includes a fourth capacitor C4 .

[0201] A first end of the fourth capacitor C4 is electrically connected to the first end of the DC conversion circuit 120 , and a second end of the fourth capacitor C4 is electrically connected to the second end of the DC conversion circuit 120 .

[0202] When the energy storage part 1 pre-charges the power factor correction circuit 110 or the DC conversion circuit 120, the energy storage part 1 first charges the first capacitor C1, then turns on the first switch unit 23, and charges the energy storage unit 25 through the first capacitor C1. After the energy storage unit 25 is completely charged, the first switch unit 23 is turned off, and then the second switch unit 24 is turned on; the control sub-circuit 3 controls the first end and the second end of the first switch device SW1 to be turned on, and controls the first end and the second end of the second switch device SW2 to be turned on, and the energy storage unit 25 pre-charges the third capacitor C3 in the power factor correction circuit 110; the control sub-circuit 3 controls the first end and the third end of the first switch device SW1 to be turned on, and controls the first end and the third end of the second switch device SW2 to be turned on, and the energy storage unit 25 pre-charges the fourth capacitor C4 in the DC conversion circuit 120.

[0203] When the power factor correction circuit 110 or the DC conversion circuit 120 discharges electric energy, it mainly passes through the third capacitor C3 or the fourth capacitor C4; the second switch unit 24 is first turned on to charge the energy storage unit 25. After the energy storage unit 25 is completely charged, the second switch unit 24 is turned off, and then the first switch unit 23 is turned on; the energy storage unit 25 charges the energy storage part 1, thereby completing the discharge and storage of electric energy.

[0204] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0205] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A circuit (100), characterized in that include: An energy storage unit (1) and a switching subcircuit (2); The energy storage unit (1) is electrically connected to the switch subcircuit (2); The switch subcircuit (2) is electrically connected to the power factor correction circuit (110) and / or the DC conversion circuit (120); The switch subcircuit (2) is configured to utilize the electric energy stored in the energy storage unit (1) to precharge the power factor correction circuit (110) or the DC conversion circuit (120); or to store the electric energy discharged by the power factor correction circuit (110) or the DC conversion circuit (120) in the energy storage unit (1).

2. The circuit (100) according to claim 1, characterized in that The switch subcircuit (2) comprises: a buck-boost module (21); The buck-boost module (21) is electrically connected to the energy storage unit (1), and the buck-boost module (21) is also electrically connected to the power factor correction circuit (110) and / or the DC conversion circuit (120); The buck-boost module (21) is configured to convert the voltage provided by the energy storage unit (1) to output a target pre-charge voltage to the power factor correction circuit (110) or the DC conversion circuit (120); or to convert the voltage discharged by the power factor correction circuit (110) or the DC conversion circuit (120) to output a target discharge voltage to the energy storage unit (1).

3. The circuit (100) according to claim 2, characterized in that The buck-boost module (21) comprises: a first switch unit (23), a second switch unit (24) and an energy storage unit (25); The first end (231) of the first switch unit (23) is electrically connected to the first end (211) of the buck-boost module (21); the second end (232) of the first switch unit (23) is electrically connected to the second end (212) of the buck-boost module (21); the second end (232) of the first switch unit (23) is also electrically connected to the second end (252) of the energy storage unit (25) and the first end (241) of the second switch unit (24); the third end (233) of the first switch unit (23) is electrically connected to the third end (213) of the buck-boost module (21); the third end of the first switch unit (23) is also electrically connected to the first end (251) of the energy storage unit (25); the second end (242) of the second switch unit (24) is electrically connected to the fourth end (214) of the buck-boost module (21); When the first switch unit (23) is turned on and the second switch unit (24) is turned off, the energy storage unit (1) is configured to charge the energy storage unit (25); after the energy storage unit (25) is charged, the first switch unit (23) is turned off and the second switch unit (24) is turned on, and the energy storage unit (25) is configured to pre-charge the power factor correction circuit (110) or the DC conversion circuit (120); When the first switch unit (23) is turned off and the second switch unit (24) is turned on, the power factor correction circuit (110) or the DC conversion circuit (120) discharges electric energy to charge the energy storage unit (25); after the energy storage unit (25) is charged, the first switch unit (23) is turned on and the second switch unit (24) is turned off, and the energy storage unit (25) is configured to charge the energy storage part (1).

4. The circuit (100) according to claim 3, characterized in that The first switch unit (23) comprises: a first capacitor (C1) and a first switch tube (Q1); The first end of the first capacitor (C1) is electrically connected to the first end (231) of the first switch unit (23), and is also electrically connected to the first end of the first switch tube (Q1); the second end of the first capacitor (C1) is electrically connected to the second end (232) of the first switch unit (23); and the second end of the first switch tube (Q1) is electrically connected to the third end (233) of the first switch unit (23).

5. The circuit (100) according to claim 3, characterized in that The second switch unit (24) includes: a second switch tube (Q2); The first end of the second switch tube (Q2) is electrically connected to the first end (241) of the second switch unit (24), and the second end of the second switch tube (Q2) is electrically connected to the second end (242) of the second switch unit (24); The energy storage unit (25) includes a first inductor (L1); The first end of the first inductor (L1) is electrically connected to the first end (251) of the energy storage unit (25), and the second end of the first inductor (L1) is electrically connected to the second end (252) of the energy storage unit (25).

6. The circuit (100) according to claim 1, characterized in that The switch subcircuit (2) further includes: a switching module (22); The switching module (22) is electrically connected to the buck-boost module (21); The switching module (22) is electrically connected to the power factor correction circuit (110) and / or the DC conversion circuit (120); The switching module (22) is configured to electrically connect the buck-boost module (21) to the power factor correction circuit (110) to pre-charge or discharge electric energy of the power factor correction circuit (110); or to electrically connect the buck-boost module (21) to the DC conversion circuit (120) to pre-charge or discharge electric energy of the DC conversion circuit (120).

7. The circuit (100) according to claim 6, characterized in that The switching module (22) comprises: a first switching device (SW1) and a second switching device (SW2); The first end (S11) of the first switch device (SW1) is electrically connected to the second end (222) of the switching module (22), the second end (S12) of the first switch device (SW1) is electrically connected to the third end (223) of the switching module (22), and the third end (S13) of the first switch device (SW1) is electrically connected to the fifth end (225) of the switching module (22); The first end (S21) of the second switch device (SW2) is electrically connected to the first end (221) of the switching module (22), the second end (S22) of the second switch device (SW2) is electrically connected to the fourth end (224) of the switching module (22), and the third end (S23) of the second switch device (SW2) is electrically connected to the sixth end (226) of the switching module (22).

8. The circuit (100) according to claim 7, characterized in that The third end (223) of the switching module (22) is electrically connected to the first end (A1) of the power factor correction circuit (110), and the fourth end (224) of the switching module (22) is electrically connected to the second end (A2) of the power factor correction circuit (110); The fifth end (225) of the switching module (22) is electrically connected to the first end (B1) of the DC conversion circuit (120), and the sixth end (226) of the switching module (22) is electrically connected to the second end (B2) of the DC conversion circuit (120).

9. The circuit (100) according to claim 7, characterized in that The pre-charge and discharge sub-circuit further includes: a control sub-circuit (3), electrically connected to the first switch device (SW1) and the second switch device (SW2); The control subcircuit (3) is configured to control the first end (S11) and the second end (S12) of the first switching device (SW1) to be turned on, and to control the first end (S21) and the second end (S22) of the second switching device (SW2) to be turned on, so as to pre-charge or discharge the power factor correction circuit (110); or to control the first end (S11) and the third end (S13) of the first switching device (SW1) to be turned on, and to control the first end (S21) and the third end (S23) of the second switching device (SW2) to be turned on, so as to pre-charge or discharge the DC conversion circuit (120).

10. The circuit (100) according to any one of claims 2 to 9, characterized in that The buck-boost module (21) further includes: a second capacitor (C2); The first end of the second capacitor (C2) is electrically connected to the first end (251) of the energy storage unit (25), and the second end of the second capacitor (C2) is electrically connected to the second end (242) of the second switch unit (24).

11. The circuit (100) according to any one of claims 1 to 9, characterized in that The energy storage unit (1) includes a photovoltaic cell.

12. A charging device (200), characterized in that: include: The circuit (100) according to any one of claims 1 to 11; a power factor correction circuit (110), wherein a first end of the power factor correction circuit (110) is electrically connected to a first end of the circuit (100), and a second end of the power factor correction circuit (110) is electrically connected to a second end of the circuit (100); A DC conversion circuit (120), wherein a first end of the DC conversion circuit (120) is electrically connected to a third end of the circuit (100), and a second end of the DC conversion circuit (120) is electrically connected to a fourth end of the circuit (100).

13. The charging device (200) according to claim 12, characterized in that The power factor correction circuit (110) comprises: a third capacitor (C3); a first end of the third capacitor (C3) is electrically connected to a first end of the power factor correction circuit (110); a second end of the third capacitor (C3) is electrically connected to a second end of the power factor correction circuit (110); The DC conversion circuit (120) comprises: a fourth capacitor (C4); a first end of the fourth capacitor (C4) is electrically connected to a first end of the DC conversion circuit (120), and a second end of the fourth capacitor (C4) is electrically connected to a second end of the DC conversion circuit (120).

14. A control method, characterized in that: A circuit (100) applied to any one of claims 1 to 11; Controlling the switch subcircuit (2) and the power factor correction circuit (110) to conduct forward or reverse, so as to pre-charge or discharge electric energy of the power factor correction circuit (110); or, The switch subcircuit (2) and the DC conversion circuit (120) are controlled to be forward-conducted or reverse-conducted, so as to pre-charge the DC conversion circuit (120) or discharge electric energy.

15. The control method according to claim 14, characterized in that: The switch subcircuit (2) comprises a first switch device (SW1) and a second switch device (SW2); Controlling the switch subcircuit (2) and the power factor correction circuit (110) to conduct forward or reverse, comprising: controlling the first end (S11) and the second end (S12) of the first switch device (SW1) to conduct, and controlling the first end (S21) and the second end (S22) of the second switch device (SW2) to conduct, so as to pre-charge or discharge electric energy of the power factor correction circuit (110); Controlling the switch subcircuit (2) and the DC conversion circuit (120) to be forward-conducted or reverse-conducted comprises: controlling the first end (S11) and the third end (S13) of the first switch device (SW1) to be conductive, and controlling the first end (S21) and the third end (S23) of the second switch device (SW2) to be conductive, so as to pre-charge or discharge electric energy of the DC conversion circuit (120).

16. The control method according to claim 14, characterized in that: The switch subcircuit (2) comprises: a first capacitor (C1), a first switch tube (Q1), a second switch tube (Q2) and a first inductor (L1); The control of the switch subcircuit (2) and the power factor correction circuit (110) or the DC conversion circuit (120) to achieve forward conduction comprises: In the first stage, the first switch tube (Q1) is controlled to be turned on and the second switch tube (Q2) is controlled to be turned off; the energy storage unit (1) charges the first inductor (L1) through the first capacitor (C1); In the second stage, the first switch tube (Q1) is controlled to be turned off and the second switch tube (Q2) is controlled to be turned on; the first inductor (L1) pre-charges the power factor correction circuit (110) or the DC conversion circuit (120).

17. The control method according to claim 16, characterized in that: In the process of controlling the switch subcircuit (2) and the power factor correction circuit (110) or the DC conversion circuit (120) to be forward-conducted, The first switch tube (Q1) is controlled to operate at a first set switching frequency and a first duty cycle.

18. The control method according to claim 17, characterized in that: Before controlling the switch subcircuit (2) and the power factor correction circuit (110) or the DC conversion circuit (120) to be forward-conducted, the method further includes: receiving precharge information, the precharge information including a target precharge voltage and a precharge time; The first set switching frequency and the first duty cycle are determined according to the pre-charge information.

19. The control method according to claim 14, characterized in that: The switch subcircuit (2) comprises: a first capacitor (C1), a first switch tube (Q1), a second switch tube (Q2) and a first inductor (L1); The control switch subcircuit (2) is reversely conductive with the power factor correction circuit (110) or the DC conversion circuit (120), and comprises: In the first stage, the first switch tube (Q1) is controlled to be turned off and the second switch tube (Q2) is controlled to be turned on; the power factor correction circuit (110) or the DC conversion circuit (120) charges the first inductor (L1); In the second stage, the first switch tube (Q1) is controlled to be turned on and the second switch tube (Q2) is controlled to be turned off; the first inductor (L1) charges the energy storage part (1) through the first capacitor (C1).

20. The control method according to claim 19, characterized in that: In the process of controlling the switch subcircuit (2) and the power factor correction circuit (110) or the DC conversion circuit (120) to conduct in reverse, The second switch tube (Q2) is controlled to operate at a second set switching frequency and a second duty cycle.

21. The control method according to claim 20, characterized in that: Before controlling the switch subcircuit (2) and the power factor correction circuit (110) or the DC conversion circuit (120) to conduct in reverse, the method further includes: receiving electric energy discharge information, wherein the electric energy discharge information includes a target discharge voltage and a discharge time; The second set switching frequency and the second duty cycle are determined according to the electric energy discharge information.

22. The control method according to any one of claims 14 to 21, characterized in that: Before controlling the switch subcircuit (2) and the power factor correction circuit (110) to be forward-conducted, the method further includes: receiving a first pre-charge instruction, the first pre-charge instruction being used to instruct the circuit (100) to pre-charge the power factor correction circuit (110); Before controlling the switch subcircuit (2) and the power factor correction circuit (110) to conduct in reverse, the method further includes: receiving a first discharge instruction, the first discharge instruction being used to instruct the circuit (100) to discharge electric energy from the power factor correction circuit (110); or Before controlling the switch subcircuit (2) and the DC conversion circuit (120) to be forward-conducted, the method further includes: receiving a second pre-charging instruction, the second pre-charging instruction being used to instruct the circuit (100) to pre-charge the DC conversion circuit (120); Before controlling the switch subcircuit (2) and the DC conversion circuit (120) to conduct in reverse, the method further includes: receiving a second discharge instruction, wherein the second discharge instruction is used to instruct the circuit (100) to discharge electric energy from the DC conversion circuit (120).

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