Interleaved parallel flying capacitor three-level bidirectional buck-boost converter and pre-charge method thereof

Abstract

Embodiments of the present application provide an interleaved parallel flying capacitor three-level bidirectional buck-boost converter and a pre-charging method thereof. The method comprises: firstly, for the interleaved parallel flying capacitor three-level bidirectional buck-boost converter, the embodiments of the present application determine target voltages of a plurality of capacitors, wherein the plurality of capacitors are input side flying capacitors, input side support capacitors, output side flying capacitors and output side support capacitors respectively; then, the embodiments of the present application control on-off states of switch tubes in an H-bridge module, so that the input side power supply of the interleaved parallel flying capacitor three-level bidirectional buck-boost converter charges each capacitor until the voltages across each capacitor reach the corresponding target voltage. Therefore, the embodiments of the present application can use the existing soft start circuit, control the on-off state of the switch tube, and pre-charge the capacitor in the converter without adding additional circuit, thereby reducing the complexity of the circuit and the cost.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to an interleaved parallel flying three-level bidirectional buck-boost converter and its pre-charging method. Background Technology

[0002] In related technologies, interleaved parallel flying capacitor three-level bidirectional buck-boost converters are commonly used in DC-DC converters in energy storage systems to achieve bidirectional energy conversion between batteries and the DC bus. Before the converter system operates, the capacitors in the converter need to be pre-charged to reduce current surges and stress on the switching transistors during system startup. However, existing solutions involve adding extra circuit components to charge the input / output flying capacitors and input / output support capacitors, resulting in complex circuitry and high costs. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an interleaved parallel flying three-level bidirectional buck-boost converter and its pre-charging method, which aims to utilize existing soft-start circuitry to pre-charge the capacitors in the converter by controlling the on / off state of the switching transistors without adding additional circuitry.

[0004] In a first aspect, embodiments of this application provide a pre-charging method for an interleaved parallel flying-cross three-level bidirectional buck-boost converter. The interleaved parallel flying-cross three-level bidirectional buck-boost converter includes a pre-charging module, an input-side support capacitor, an output-side support capacitor, and two parallel-connected H-bridge modules. Each H-bridge module includes an input-side flying-cross capacitor, an output-side flying-cross capacitor, an input-side bridge arm, an output-side bridge arm, and an inductor. The input-side bridge arm includes a first, second, third, and fourth switch connected in sequence, and the output-side bridge arm includes a fifth, sixth, seventh, and eighth switch connected in sequence. The method includes:

[0005] Determine the target voltage of multiple capacitors, wherein the multiple capacitors are the input-side flying capacitor, the input-side supporting capacitor, the output-side flying capacitor, and the output-side supporting capacitor;

[0006] The switching state of the switching transistors in the H-bridge module is controlled so that the input power supply of the interleaved parallel flying three-level bidirectional buck-boost converter charges each capacitor until the voltage across each capacitor reaches the corresponding target voltage.

[0007] According to some embodiments of this application, controlling the on / off state of the switching transistors in the H-bridge module to charge each of the capacitors via the input power supply of the interleaved parallel flying-cross three-level bidirectional buck-boost converter includes:

[0008] The on / off states of the pre-charge module, the first switch, and the fourth switch are controlled to charge the input-side support capacitor and the input-side flying capacitor in the H-bridge module.

[0009] When the input-side support capacitor and the input-side flying capacitor have completed charging, the eighth switch is turned on;

[0010] For at least one of the H-bridge modules, the on / off states of the first switch, the second switch, and the seventh switch are synchronously controlled based on the same PWM signal to charge the output-side flying capacitor and the output-side supporting capacitor.

[0011] According to some embodiments of this application, the pre-charging module includes a main switch, an auxiliary switch, and a resistor, wherein the auxiliary switch and the resistor are connected in series and then in parallel across the main switch; controlling the on / off states of the pre-charging module, the first switch, and the fourth switch to charge the input-side support capacitor and the input-side flying capacitor in the H-bridge module includes:

[0012] The auxiliary switch, the first switch, and the fourth switch are turned on to enable charging of the input-side support capacitor and the input-side flying capacitor;

[0013] When it is determined that the voltage across the input-side flying capacitor reaches the first target voltage, the first switch and the fourth switch corresponding to the input-side flying capacitor are turned off, while the auxiliary switch remains on.

[0014] When the voltage across the input-side support capacitor reaches the second target voltage, the main circuit switch is turned on and the auxiliary switch is turned off.

[0015] According to some embodiments of this application, the step of synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal for at least one of the H-bridge modules to charge the output-side flying capacitor and the output-side supporting capacitor includes:

[0016] For each of the H-bridge modules, the eighth switch is kept on, and the on / off states of the first, second, and seventh switches are synchronously controlled based on the same PWM signal to charge the output-side support capacitor and the output-side flying capacitor through the inductor.

[0017] According to some embodiments of this application, after synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal, the method further includes:

[0018] For each of the H-bridge modules, when the voltage across the output-side flying capacitor reaches the third target voltage, the on / off states of the first, second, seventh, and eighth switches are synchronously controlled based on the same PWM signal to continue charging the output-side support capacitor through the inductor.

[0019] According to some embodiments of this application, after synchronously controlling the on / off states of the first switch, the second switch, the seventh switch, and the eighth switch based on the same PWM signal, the method further includes:

[0020] When the voltage across the output-side support capacitor reaches the fourth target voltage, the first, second, seventh, and eighth switches in all H-bridge modules are turned off.

[0021] According to some embodiments of this application, the two H-bridge modules are respectively a first H-bridge module and a second H-bridge module; the step of synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal for at least one H-bridge module to charge the output-side flying capacitor and the output-side supporting capacitor includes:

[0022] Turn on the fifth switch in the second H-bridge module, and keep the eighth switch in both the first H-bridge module and the second H-bridge module on.

[0023] For the first H-bridge module, the on / off states of the first switch, the second switch, and the seventh switch are synchronously controlled based on the same PWM signal, so as to charge the output-side support capacitor and the output-side flying capacitor in the first H-bridge module and the second H-bridge module through the inductance of the first H-bridge module.

[0024] According to some embodiments of this application, after synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal, the method further includes:

[0025] When the voltage across the flying capacitor on the output side of the second H-bridge module reaches the third target voltage, the fifth switch and / or the eighth switch in the second H-bridge module are turned off.

[0026] According to some embodiments of this application, after synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal, the method further includes:

[0027] When the voltage across the flying capacitor on the output side in the first H-bridge module reaches the third target voltage, the on / off states of the first, second, seventh, and eighth switches in the first H-bridge module are synchronously controlled based on the same PWM signal, so as to continue charging the output-side support capacitor through the inductor in the first H-bridge module.

[0028] According to some embodiments of this application, when the voltage across the flying capacitor on the output side of both the first H-bridge module and the second H-bridge module reaches the third target voltage, the method further includes:

[0029] When the voltage across the output-side support capacitor reaches the fourth target voltage, all the first, second, seventh, and eighth switches in the first H-bridge module are turned off.

[0030] According to some embodiments of this application, before controlling the on / off states of the pre-charge module, the first switch, and the fourth switch, the method further includes:

[0031] For each H-bridge module, the on / off states of the first switch, the second switch, the seventh switch and the eighth switch are synchronously controlled based on the first PWM signal, and the on / off states of the third switch, the fourth switch, the fifth switch and the sixth switch are synchronously controlled based on the second PWM signal.

[0032] The first PWM signal and the second PWM signal are complementary PWM signals.

[0033] Secondly, embodiments of this application provide a controller, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor runs the computer program, it performs the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter described in the first aspect.

[0034] Thirdly, embodiments of this application provide an interleaved parallel flying three-level bidirectional buck-boost converter, including the controller described in the second aspect above.

[0035] Fourthly, embodiments of this application provide a power supply device including the interleaved parallel flying three-level bidirectional buck-boost converter described in the third aspect above.

[0036] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions for performing a pre-charging method for an interleaved parallel flying-cross three-level bidirectional buck-boost converter as described in the first aspect above.

[0037] Sixthly, embodiments of this application provide a computer program product, including a computer program or computer instructions, characterized in that the computer program or computer instructions are stored in a computer-readable storage medium, a processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, causing the computer device to perform the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter as described in the first aspect above.

[0038] According to the technical solution of this application embodiment, at least the following beneficial effects are achieved: For an interleaved parallel flying-bridge three-level bidirectional buck-boost converter, firstly, this application embodiment determines the target voltage of each capacitor, including the input-side flying-bridge capacitor, the input-side supporting capacitor, the output-side flying-bridge capacitor, and the output-side supporting capacitor; then, this application embodiment controls the on / off state of the switching transistors in the H-bridge module to charge each capacitor with the input-side power supply of the interleaved parallel flying-bridge three-level bidirectional buck-boost converter until the voltage across each capacitor reaches the corresponding target voltage. Therefore, this application embodiment can utilize existing soft-start circuitry and control the on / off state of the switching transistors to achieve pre-charging of the capacitors in the converter without adding additional circuitry, reducing circuit complexity and cost.

[0039] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0040] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0041] Figure 1 This is a schematic diagram of the structure of an interleaved parallel flying three-level bidirectional buck-boost converter provided in one embodiment of this application;

[0042] Figure 2 This is a flowchart of a pre-charging method for an interleaved parallel flying three-level bidirectional buck-boost converter provided in one embodiment of this application;

[0043] Figure 3 yes Figure 2 A flowchart of a sub-step of one embodiment of step S220 shown;

[0044] Figure 4 yes Figure 3 A flowchart of a sub-step of an embodiment of step S310 shown;

[0045] Figure 5 yes Figure 3 A flowchart of a sub-step of one embodiment of step S330 shown in the diagram;

[0046] Figure 6 This is a flowchart of stopping the charging of the output-side flying capacitor provided in one embodiment of this application;

[0047] Figure 7 This is a flowchart of stopping the charging of the output-side support capacitor provided in one embodiment of this application;

[0048] Figure 8 yes Figure 3 A flowchart of a sub-step of another embodiment of step S330 shown in the diagram;

[0049] Figure 9 This is a flowchart of stopping the charging of the output-side flying capacitor in the second H-bridge module according to one embodiment of this application;

[0050] Figure 10 This is a flowchart of stopping the charging of the output-side flying capacitor in the first H-bridge module according to one embodiment of this application;

[0051] Figure 11 This is a flowchart of stopping the charging of the output-side support capacitor provided in another embodiment of this application;

[0052] Figure 12 This is a flowchart of discharging all capacitors provided in one embodiment of this application;

[0053] Figure 13 This is a schematic diagram of a controller for performing a pre-charge method for an interleaved parallel-interleaved parallel-flying three-level bidirectional buck-boost converter, according to an embodiment of this application. Detailed Implementation

[0054] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0055] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0056] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0057] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0058] In some applications, interleaved parallel flying capacitor three-level bidirectional buck-boost converters are commonly used in energy storage systems to achieve bidirectional energy conversion between the battery and the DC bus. Before the converter system operates, the capacitors in the converter need to be pre-charged to reduce current surges and stress on the switching transistors during system startup. However, existing solutions involve adding extra circuit components to charge the input / output flying capacitors and input / output support capacitors, resulting in complex circuitry and high costs.

[0059] Based on the above, this application proposes an interleaved parallel flying three-level bidirectional buck-boost converter and its pre-charging method, which aims to utilize existing soft-start circuitry to pre-charge the capacitors in the converter by controlling the on / off state of the switching transistors without adding additional circuitry.

[0060] The various embodiments of the interleaved parallel flying three-level bidirectional buck-boost converter of this application will be further described below with reference to the accompanying drawings.

[0061] like Figure 1 As shown, Figure 1 This is a circuit diagram of an interleaved parallel flying three-level bidirectional buck-boost converter provided in one embodiment of this application.

[0062] In one embodiment, the interleaved parallel flying-cross three-level bidirectional buck-boost converter includes, but is not limited to, an input-side support capacitor Cin, an output-side support capacitor Cout, and two parallel H-bridge modules 100. Each H-bridge module 100 includes an input-side flying-cross capacitor, an output-side flying-cross capacitor, an input-side bridge arm, an output-side bridge arm, and an inductor. The input side of the interleaved parallel flying-cross three-level bidirectional buck-boost converter is connected to the input-side bridge arm of each H-bridge module 100 via the input-side support capacitor Cin. The output-side bridge arm of each H-bridge module 100 is connected to the output side of the interleaved parallel flying-cross three-level bidirectional buck-boost converter via the output-side support capacitor Cout. The input-side bridge arm and the output-side bridge arm are connected by an inductor.

[0063] In one embodiment, the input-side bridge arm includes, but is not limited to, a first switch, a second switch, a third switch, and a fourth switch connected in sequence, and the output-side bridge arm includes, but is not limited to, a fifth switch, a sixth switch, a seventh switch, and an eighth switch connected in sequence, with the common terminal of the second and third switches connected to the common terminal of the sixth and seventh switches via an inductor.

[0064] In one embodiment, the two ends of the input-side support capacitor Cin are respectively connected to the two ends of the input-side bridge arm, that is, one end of the input-side support capacitor Cin is connected to one end of the first switch transistor and the other end is connected to one end of the fourth switch transistor; one end of the input-side flying capacitor is connected to the common terminal between the first switch transistor and the second switch transistor, and the other end is connected to the common terminal between the third switch transistor and the fourth switch transistor.

[0065] In one embodiment, the two ends of the output-side support capacitor Cout are respectively connected to the two ends of the output-side bridge arm, that is, one end of the output-side support capacitor Cout is connected to one end of the fifth switch and the other end is connected to one end of the eighth switch; one end of the output-side flying capacitor is connected to the common terminal between the fifth and sixth switches and the other end is connected to the common terminal between the seventh and eighth switches.

[0066] In one embodiment, the interleaved parallel flying three-level bidirectional buck-boost converter also includes, but is not limited to, a pre-charge module 200, which is disposed on the input bus. The pre-charge module 200 includes a main switch K1, an auxiliary switch K2, and a resistor R. The auxiliary switch K2 and the resistor R are connected in series and then in parallel on both sides of the main switch K1.

[0067] In one embodiment, the interleaved parallel flying three-level bidirectional buck-boost converter also includes, but is not limited to, an output relay, which is located on the output bus.

[0068] In one embodiment, the two H-bridge modules 100 are a first H-bridge module and a second H-bridge module, respectively, as shown below. Figure 1 As shown, the first switch in the first H-bridge module is Q11, the second switch is Q21, the third switch is Q31, the fourth switch is Q41, the fifth switch is Q51, the sixth switch is Q61, the seventh switch is Q71, and the eighth switch is Q81.

[0069] The first switch in the second H-bridge module is Q12, the second switch is Q22, the third switch is Q32, the fourth switch is Q42, the fifth switch is Q52, the sixth switch is Q62, the seventh switch is Q72, and the eighth switch is Q82.

[0070] Based on the hardware structure of the interleaved parallel flying three-level bidirectional buck-boost converter in the above embodiments, the following presents various embodiments of the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of this application.

[0071] like Figure 2 As shown, Figure 2 This is a flowchart of a pre-charging method for an interleaved parallel flying-cross three-level bidirectional buck-boost converter provided in one embodiment of this application; the pre-charging method for the interleaved parallel flying-cross three-level bidirectional buck-boost converter may include, but is not limited to, steps S210 and S220.

[0072] Step S210: Determine the target voltage of multiple capacitors, wherein the multiple capacitors are the input-side flying capacitor, the input-side supporting capacitor, the output-side flying capacitor, and the output-side supporting capacitor.

[0073] Step S220: Control the on / off state of the switching transistors in the H-bridge module so that the input power supply of the interleaved parallel flying three-level bidirectional buck-boost converter charges each capacitor until the voltage across each capacitor reaches the corresponding target voltage.

[0074] In one embodiment, this application embodiment can determine the target voltages of the input-side flying capacitor and the input-side supporting capacitor based on the input-side power supply voltage of the interleaved parallel flying three-level bidirectional buck-boost converter. Simultaneously, it can also determine the target voltages of the output-side flying capacitor and the output-side supporting capacitor based on the output-side bus voltage of the interleaved parallel flying three-level bidirectional buck-boost converter. Furthermore, this application embodiment can utilize existing soft-start circuitry, i.e., by controlling the on / off states of all existing switches in the interleaved parallel flying three-level bidirectional buck-boost converter, to pre-charge all capacitors in the converter. This differs from existing technologies that require additional circuitry for charging; therefore, this application embodiment can reduce circuit complexity and lower costs.

[0075] like Figure 3 As shown, Figure 3 yes Figure 2 The flowchart shows a sub-step of one embodiment of step S220; step S220 may include, but is not limited to, steps S310, S320 and S330.

[0076] Step S310: Control the on / off state of the pre-charge module, the first switch and the fourth switch to charge the input-side support capacitor and the input-side flying capacitor in the H-bridge module.

[0077] Step S320: After the input-side support capacitor and the input-side flying capacitor have completed charging, turn on the eighth switch.

[0078] Step S330: For at least one H-bridge module, the on / off states of the first, second, and seventh switching transistors are synchronously controlled based on the same PWM signal to charge the output-side flying capacitor and the output-side supporting capacitor.

[0079] In one embodiment, the input-side capacitors can be charged first. This is achieved by controlling a pre-charging module, a first switch, and a fourth switch to charge the input-side supporting capacitor and the input-side flying capacitor in each H-bridge module. The switching of the first and fourth switches controls whether current flows through the input-side flying capacitor. When all input-side capacitors are fully charged, the eighth switch in each H-bridge module is turned on to prepare for subsequent charging of the output-side capacitors. Next, the embodiment synchronously controls the first, second, and seventh switches in at least one H-bridge module based on the same PWM signal to charge the output-side supporting capacitor and the output-side flying capacitor in each H-bridge module. Therefore, the embodiment can utilize existing soft-start circuitry and control the switching of switches to pre-charge the capacitors in the converter without adding additional circuitry, reducing circuit complexity and cost.

[0080] In addition, such as Figure 4 As shown, Figure 4 yes Figure 3 The flowchart shows a sub-step of one embodiment of step S310 shown; step S310 may include, but is not limited to, steps S410, S420 and S430.

[0081] Step S410: Turn on the auxiliary switch, the first switch and the fourth switch to start charging the input-side support capacitor and the input-side flying capacitor;

[0082] Step S420: When it is determined that the voltage across the input-side flying capacitor reaches the first target voltage, turn off the first and fourth switching transistors corresponding to the input-side flying capacitor, and keep the auxiliary switch on.

[0083] Step S430: When the voltage across the input-side support capacitor reaches the second target voltage, turn on the main circuit switch and turn off the auxiliary switch.

[0084] In one embodiment, the charging process of the input-side capacitor is as follows: First, after the auxiliary switch, the first switch, and the fourth switch are turned on, the auxiliary switch and the input-side support capacitor together form a charging circuit for the input-side support capacitor, thereby charging the input-side support capacitor. At the same time, the auxiliary switch, the first switch, the input-side flying capacitor, and the fourth switch together form a charging circuit for the input-side flying capacitor, thereby charging the input-side flying capacitor.

[0085] Next, since the first target voltage of the input-side flying capacitor is typically half of the second target voltage of the input-side supporting capacitor, the voltage across the input-side flying capacitor will reach the first target voltage first during the charging process. Therefore, in this embodiment, the first and fourth switching transistors are turned off to stop charging the input-side flying capacitor. Simultaneously, the auxiliary switch remains on to continue charging the input-side supporting capacitor. Then, when the voltage across the input-side supporting capacitor reaches the second target voltage, the main circuit switch is turned on, the auxiliary switch is turned off, and the charging of the output-side capacitor begins.

[0086] It should be noted that, regarding the first target voltage and the second target voltage mentioned above, the second target voltage can be equal to the battery voltage on the input side of the converter, and the first target voltage can be half of the battery voltage on the input side of the converter.

[0087] In addition, such as Figure 5 As shown, Figure 5 yes Figure 3 The flowchart shows a sub-step of one embodiment of step S330 shown; step S330 may include, but is not limited to, steps S510 and S520.

[0088] Step S510: For each H-bridge module, keep the eighth switch on;

[0089] Step S520: Based on the same PWM signal, synchronously control the on / off states of the first, second, and seventh switching transistors to charge the output-side support capacitor and the output-side flying capacitor through the inductor.

[0090] In one embodiment, such as Figure 1 As shown, for both the first and second H-bridge modules, the eighth switch in the first H-bridge module remains on, and the eighth switch in the second H-bridge module remains on. Then, for the first H-bridge module, the on / off states of the first, second, and seventh switches are synchronously controlled based on the same PWM signal to charge the output-side support capacitor and the output-side flying capacitor of the first H-bridge module through the inductor. Simultaneously, for the second H-bridge module, the on / off states of the first, second, and seventh switches are synchronously controlled based on the same PWM signal to charge the output-side support capacitor and the output-side flying capacitor of the second H-bridge module through the inductor.

[0091] In each H-bridge module, when the first, second, and seventh switches are turned off, the fourth, third, inductors, sixth, output-side flying capacitors, and eighth switches will together form a charging circuit for the output-side flying capacitor; at the same time, the fourth, third, inductors, sixth, and fifth switches and the output-side support capacitors will together form a charging circuit for the output-side support capacitors.

[0092] In addition, such as Figure 6 As shown, Figure 6 This is a flowchart of stopping the charging of the output-side flying capacitor provided in one embodiment of this application; after performing the above step S520, the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter may also include, but is not limited to, steps S610 and S620.

[0093] Step S610: Monitor the voltage across the flying capacitor on the output side of each H-bridge module;

[0094] Step S620: For each H-bridge module, when the voltage across the output-side flying capacitor reaches the third target voltage, the on / off states of the first, second, seventh, and eighth switching transistors are synchronously controlled based on the same PWM signal to continue charging the output-side support capacitor through the inductor.

[0095] In one embodiment, when using Figure 5 When the method shown charges the output-side flying capacitor and the output-side support capacitor, this embodiment of the application will monitor the voltage across the output-side flying capacitor in each H-bridge module in real time. If the voltage across the output-side flying capacitor in a certain H-bridge module reaches the third target voltage, that is, when the output-side flying capacitor is fully charged, this embodiment of the application will synchronously control the on / off states of the first, second, seventh, and eighth switches based on the same PWM signal to stop charging the output-side flying capacitor, and continue to charge the output-side support capacitor through the inductor.

[0096] Specifically, for each H-bridge module, when the first, second, seventh, and eighth switches are turned off, the eighth switch is in the off state, so the charging circuit for the output-side flying capacitor cannot be formed, thus stopping the charging of the output-side flying capacitor.

[0097] In addition, such as Figure 7 As shown, Figure 7 This is a flowchart of stopping the charging of the output-side support capacitor provided in one embodiment of this application; after performing the above step S620, the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter may also include, but is not limited to, steps S710 and S720.

[0098] Step S710: Monitor the voltage across the output-side support capacitor;

[0099] Step S720: When the voltage across the output-side support capacitor reaches the fourth target voltage, turn off the first, second, seventh, and eighth switches in all H-bridge modules.

[0100] In one embodiment, when using Figure 5 When the method shown charges the output-side flying capacitor and the output-side supporting capacitor, this embodiment of the application will monitor the voltage across the output-side supporting capacitor in real time. If the voltage across the output-side supporting capacitor reaches the fourth target voltage, that is, when the output-side supporting capacitor is fully charged, this embodiment of the application will turn off the first, second, seventh, and eighth switches in all H-bridge modules, thereby stopping the charging of the output-side supporting capacitor.

[0101] In addition, such as Figure 8 As shown, Figure 8 yes Figure 3 The flowchart shows a sub-step of another embodiment of step S330 shown; step S330 may also include, but is not limited to, steps S810 and S820.

[0102] Step S810: Turn on the fifth switch in the second H-bridge module, and keep the eighth switch in the first H-bridge module and the second H-bridge module on.

[0103] Step S820: For the first H-bridge module, the on / off states of the first switch, the second switch, and the seventh switch are synchronously controlled based on the same PWM signal, so as to charge the output-side support capacitor and the output-side flying capacitor in the first H-bridge module and the second H-bridge module through the inductance of the first H-bridge module.

[0104] In one embodiment, in addition to employing Figure 5 In addition to charging the output-side flying capacitor and the output-side supporting capacitor using the method shown, embodiments of this application can also charge the output-side flying capacitor and the output-side supporting capacitor by the following means: such as Figure 1 As shown, firstly, for the second H-bridge module, the fifth and eighth switches are kept on; secondly, for the first H-bridge module, the eighth switch is kept on, and the first, second, and seventh switches in the first H-bridge module are synchronously controlled based on the same PWM signal, so that the output-side support capacitor and the output-side flying capacitor in the first and second H-bridge modules are charged simultaneously through the inductance of the first H-bridge module.

[0105] Specifically, when the first, second, and seventh switches in the first H-bridge module are off, the fourth, third, inductor, sixth, output-side flying capacitor, and eighth switches in the first H-bridge module will together form the charging circuit for the output-side flying capacitor in the first H-bridge module; simultaneously, the fourth, third, inductor, sixth, and fifth switches in the first H-bridge module, along with the output-side support capacitor, will together form the charging circuit for the output-side support capacitor; and simultaneously, the fourth, third, inductor, sixth, and fifth switches in the first H-bridge module, along with the fifth switch, output-side flying capacitor, and eighth switches in the second H-bridge module, will together form the charging circuit for the output-side flying capacitor in the second H-bridge module.

[0106] In addition, such as Figure 9 As shown, Figure 9 This is a flowchart of stopping the charging of the output-side flying capacitor in the second H-bridge module according to one embodiment of this application; after performing the above step S820, the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter may also include, but is not limited to, steps S910 and S920.

[0107] Step S910: Monitor the voltage across the flying capacitor on the output side of the second H-bridge module;

[0108] Step S920: When the voltage across the flying capacitor on the output side of the second H-bridge module reaches the third target voltage, turn off the fifth and / or eighth switching transistors in the second H-bridge module.

[0109] In one embodiment, when using Figure 8 When the method shown charges the output-side flying capacitor and the output-side support capacitor, this embodiment monitors the voltage across the output-side flying capacitor in the second H-bridge module in real time. If the voltage across the output-side flying capacitor in the second H-bridge module reaches the third target voltage, that is, when the output-side flying capacitor in the second H-bridge module is fully charged, this embodiment turns off the fifth and / or eighth switching transistors in the second H-bridge module, thereby stopping the charging of the output-side flying capacitor in the second H-bridge module. However, at this time, the charging of the output-side support capacitor and the output-side flying capacitor in the first H-bridge module will continue through the inductor in the first H-bridge module.

[0110] In addition, such as Figure 10 As shown, Figure 10 This is a flowchart of stopping the charging of the output-side flying capacitor in the first H-bridge module according to one embodiment of this application; after performing the above step S820, the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter may also include, but is not limited to, steps S1010 and S1020.

[0111] Step S1010: Monitor the voltage across the flying capacitor on the output side of the first H-bridge module;

[0112] Step S1020: When the voltage across the flying capacitor on the output side in the first H-bridge module reaches the third target voltage, the on / off states of the first, second, seventh, and eighth switching transistors in the first H-bridge module are synchronously controlled based on the same PWM signal, so as to continue charging the output-side support capacitor through the inductor in the first H-bridge module.

[0113] In one embodiment, when using Figure 8 When the method shown charges the output-side flying capacitor and the output-side supporting capacitor, this embodiment monitors the voltage across the output-side flying capacitor in the first H-bridge module in real time. If the voltage across the output-side flying capacitor in the first H-bridge module reaches the third target voltage, that is, when the output-side flying capacitor in the first H-bridge module is fully charged, this embodiment synchronously controls the on / off states of the first, second, seventh, and eighth switches in the first H-bridge module based on the same PWM signal to stop charging the output-side flying capacitor in the first H-bridge module. However, at this time, the charging of the output-side supporting capacitor will continue through the inductor in the first H-bridge module.

[0114] In addition, such as Figure 11 As shown, Figure 11 This is a flowchart of stopping the charging of the output-side support capacitor provided in another embodiment of this application; when the voltages across the output-side flying capacitors in the first H-bridge module and the second H-bridge module both reach the third target voltage, the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter may also include, but is not limited to, steps S1110 and S1120.

[0115] Step S1110: Monitor the voltage across the output-side support capacitor;

[0116] Step S1120: When the voltage across the output-side support capacitor reaches the fourth target voltage, turn off the first, second, seventh, and eighth switches in all the first H-bridge modules.

[0117] In one embodiment, if the voltage across the output-side supporting capacitor reaches the fourth target voltage, i.e., when the output-side supporting capacitor is fully charged, this embodiment will turn off the first, second, seventh, and eighth switches in all the first H-bridge modules, thereby completing the charging process of the output-side supporting capacitor.

[0118] In addition, such as Figure 12 As shown, Figure 12This is a flowchart of discharging all capacitors provided in one embodiment of this application; before performing step S310, the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter may also include, but is not limited to, steps S1210 and S1220.

[0119] Step S1210: For each H-bridge module, the on / off states of the first switch, the second switch, the seventh switch and the eighth switch are synchronously controlled based on the first PWM signal to discharge the input-side support capacitor and the input-side flying capacitor.

[0120] Step S1220: Based on the second PWM signal, synchronously control the on / off states of the third, fourth, fifth, and sixth switching transistors to discharge the output-side supporting capacitor and the output-side flying capacitor; wherein, the first PWM signal and the second PWM signal are complementary PWM signals.

[0121] In one embodiment, after the system is powered on, only the battery has voltage, all switches and relays are in the off state, and the voltage state of all capacitors is uncertain, potentially resulting in residual charge. To address this, this embodiment configures the DSP's PWM output so that the signals of the first, second, seventh, and eighth switches are synchronized first PWM signals, and the signals of the third, fourth, fifth, and sixth switches are synchronized second PWM signals. The first and second PWM signals are complementary, and their duty cycle can be 50%. This is an no-load mode, and the current through the inductors is reactive. The losses from the reactive current due to line impedance and the switching losses of all switches quickly dissipate the residual energy in the input and output capacitors, eliminating internal residual charge. This eliminates the need for complex pre-charge logic classification based on internal capacitor voltage levels and satisfies the startup conditions for all residual charge.

[0122] When the first, second, seventh, and eighth switches are controlled synchronously, the first, second, and inductors together form the discharge circuit of the input-side supporting capacitor. At the same time, the second, inductors together form the discharge circuit of the input-side flying capacitor.

[0123] In addition, when the third, fourth, fifth, and sixth switches are controlled synchronously, the fifth, sixth, and inductors together form the discharge circuit of the output-side supporting capacitor. At the same time, the sixth, inductors together form the discharge circuit of the output-side flying capacitor.

[0124] Therefore, this application embodiment uses PWM open-loop chopping loss technology to utilize the losses of the switching transistor and the active power loss generated by the reactive current on the circuit impedance, thereby eliminating the residual charge of the internal input-side capacitor and output-side capacitor, and thus resetting all internal operating conditions to the same operating condition, solving the problem of complex operating conditions.

[0125] Based on the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter in the above embodiments, several overall embodiments of the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of this application are presented below.

[0126] In one embodiment, such as Figure 1 As shown, Q11, Q41, Q12, and Q42 are turned on, and auxiliary switch K2 is closed. The input power supply Uin charges Cin, Cf1, and Cf2 through resistor R. When the voltages of Cf1 and Cf2 reach the target voltage values, Q11, Q41, Q12, and Q42 are turned off. The input power supply Uin continues to charge Cin through resistor R. When the voltage of Cin reaches Uin, K1 is closed and K2 is opened. Q81 and Q82 are turned on, and Q11, Q21, Q71, Q12, Q22, and Q72 are controlled by the same PWM switch. The input power supply Uin supplies Cf3 through L1. Cout is charged, and Cf4 and Cout are charged through L2. After Cf3 voltage reaches the target voltage value, the same PWM switch of Q11, Q21, Q71, and Q81 is controlled, and the input power supply Uin continues to charge Cout through L1. After Cf4 voltage reaches the target voltage value, the same PWM switch of Q12, Q22, Q72, and Q82 is controlled, and the input power supply Uin continues to charge Cout through L2. After Cout is charged to the target power value, Q11, Q21, Q71, Q81, Q12, Q22, Q72, and Q82 are turned off, and the pre-charging is completed.

[0127] In one embodiment, such as Figure 1As shown, control Q11, Q41, Q12, and Q42 to turn on, close auxiliary switch K2, and the input power supply Uin charges Cin, Cf1, and Cf2 through resistor R. Once Cf1 and Cf2 reach their target voltage values, control Q11, Q41, Q12, and Q42 to turn off, and the input power supply Uin continues to charge Cin through resistor R. Once Cin's voltage reaches Uin's value, K1 closes and K2 opens. Control Q81, Q52, and Q82 to turn on, and control Q11, Q2... 1. With the same PWM switch Q71, the input power supply Uin charges Cf3, Cf4, and Cout through L1. After Cf4 voltage reaches the target voltage, Q52 and Q82 are turned off. After Cf3 voltage reaches the target voltage, Q11, Q21, Q71, and Q81 are controlled to use the same PWM switch, and the input power supply Uin continues to charge Cout through L1. After Cout is charged to the target power value, Q11, Q21, Q71, and Q81 are turned off, and the pre-charging is completed.

[0128] In one embodiment, such as Figure 1 As shown, control Q11, Q41, Q12, and Q42 to turn on, close auxiliary switch K2, and the input power supply Uin charges Cin, Cf1, and Cf2 through resistor R. Once Cf1 and Cf2 reach their target voltage values, control Q11, Q41, Q12, and Q42 to turn off, and the input power supply Uin continues to charge Cin through resistor R. Once Cin's voltage reaches Uin's value, K1 closes and K2 opens. Control Q81, Q51, and Q82 to turn on, and control Q12 and Q2... 2. With the same PWM switch Q72, the input power supply Uin charges Cf3, Cf4, and Cout through L2. After Cf3 voltage reaches the target voltage, Q51 and Q81 are turned off. After Cf4 voltage reaches the target voltage, Q12, Q22, Q72, and Q82 are controlled to use the same PWM switch, and the input power supply Uin continues to charge Cout through L2. After Cout is charged to the target power value, Q12, Q22, Q72, and Q82 are turned off, and the pre-charging is completed.

[0129] Based on the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter based on the above embodiments, the following presents various embodiments of the controller, interleaved parallel flying three-level bidirectional buck-boost converter, power supply device, computer-readable storage medium, and computer program product of this application.

[0130] like Figure 13 As shown, Figure 13 This is a schematic diagram of a controller for performing a pre-charge method for an interleaved parallel fly-through three-level bidirectional buck-boost converter, according to an embodiment of this application. The controller 300 implemented in this application includes: a processor 310, a memory 320, and a computer program stored in the memory 320 and executable on the processor 310, wherein... Figure 13The example uses a processor 310 and a memory 320.

[0131] The processor 310 and the memory 320 can be connected via a bus or other means. Figure 13 Taking the example of a connection between China and Israel via a bus.

[0132] Memory 320, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory 320 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 320 may optionally include remotely located memories 320 relative to processor 310, which can be connected to controller 300 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0133] Those skilled in the art will understand that Figure 13 The device structure shown does not constitute a limitation on the controller 300 and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0134] exist Figure 13 In the controller 300 shown, the processor 310 can be used to call the control program stored in the memory 320, thereby implementing the pre-charging method of the interleaved parallel flying-across three-level bidirectional buck-boost converter described above. Specifically, the non-transient software program and instructions required to implement the pre-charging method of the interleaved parallel flying-across three-level bidirectional buck-boost converter of the above embodiment are stored in the memory 320. When executed by the processor 310, the pre-charging method of the interleaved parallel flying-across three-level bidirectional buck-boost converter of the above embodiment is executed.

[0135] It is worth noting that, since the controller 300 of this application embodiment is capable of executing the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above embodiments, the specific implementation method and technical effects of the controller 300 of this application embodiment can refer to the specific implementation method and technical effects of the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above embodiments.

[0136] Furthermore, one embodiment of this application provides an interleaved parallel flying three-level bidirectional buck-boost converter, which includes the controller described in the above embodiment.

[0137] It is worth noting that, since the interleaved parallel flying three-level bidirectional buck-boost converter of this application includes the controller of the above-described embodiments, and the controller of the above-described embodiments is capable of executing the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above-described embodiments, the specific implementation method and technical effects of the interleaved parallel flying three-level bidirectional buck-boost converter of this application can be referred to the specific implementation method and technical effects of the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above-described embodiments.

[0138] Furthermore, one embodiment of this application also provides a power supply device that includes the interleaved parallel flying three-level bidirectional buck-boost converter of the above embodiments.

[0139] It is worth noting that, since the power supply device of this application embodiment includes the interleaved parallel flying three-level bidirectional buck-boost converter of the above embodiments, and the interleaved parallel flying three-level bidirectional buck-boost converter of the above embodiments includes the controller of the above embodiments, and the controller of the above embodiments can execute the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above embodiments, the specific implementation method and technical effect of the power supply device of this application embodiment can refer to the specific implementation method and technical effect of the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above embodiments.

[0140] Furthermore, one embodiment of this application provides a computer-readable storage medium storing computer-executable instructions for performing the pre-charging method of the aforementioned interleaved parallel flying-cross three-level bidirectional buck-boost converter. Exemplarily, the above-described method is performed... Figures 2 to 12 The methods and steps in the text.

[0141] It is worth noting that, since the computer-readable storage medium of this application embodiment is capable of executing the pre-charging method of the interleaved parallel flying-cross three-level bidirectional buck-boost converter of any of the above embodiments, the specific implementation and technical effects of the computer-readable storage medium of this application embodiment can be referred to the specific implementation and technical effects of the pre-charging method of the interleaved parallel flying-cross three-level bidirectional buck-boost converter of any of the above embodiments.

[0142] Furthermore, one embodiment of this application also provides a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform the pre-charge method of the interleaved parallel flying-cross three-level bidirectional buck-boost converter described above. Exemplarily, the above-described... Figures 2 to 12 The methods and steps in the text.

[0143] It is worth noting that, since the computer program product of this application embodiment can execute the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above embodiments, the specific implementation method and technical effect of the computer program product of this application embodiment can refer to the specific implementation method and technical effect of the pre-charging method of the interleaved parallel flying three-level bidirectional buck-boost converter of any of the above embodiments.

[0144] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0145] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0146] In the several embodiments provided in this application, it should be understood that the disclosed systems, instruments, and methods can be implemented in other ways. For example, the instrument embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between instruments or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0147] It should also be understood that the various implementation methods provided in this application can be combined arbitrarily to achieve different technical effects.

[0148] The above provides a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A pre-charging method for an interleaved parallel flying three-level bidirectional buck-boost converter, characterized in that, The interleaved parallel flying-crossover three-level bidirectional buck-boost converter includes a pre-charge module, an input-side support capacitor, an output-side support capacitor, and two parallel-connected H-bridge modules. Each H-bridge module includes an input-side flying-crossover capacitor, an output-side flying-crossover capacitor, an input-side bridge arm, an output-side bridge arm, and an inductor. The input-side bridge arm includes a first, second, third, and fourth switch connected in sequence, and the output-side bridge arm includes a fifth, sixth, seventh, and eighth switch connected in sequence. The method includes: Determine the target voltage of multiple capacitors, wherein the multiple capacitors are the input-side flying capacitor, the input-side supporting capacitor, the output-side flying capacitor, and the output-side supporting capacitor; The switching state of the switching transistors in the H-bridge module is controlled so that the input power supply of the interleaved parallel flying three-level bidirectional buck-boost converter charges each capacitor until the voltage across each capacitor reaches the corresponding target voltage.

2. The method according to claim 1, characterized in that, The control of the on / off state of the switching transistors in the H-bridge module, so that the input power supply of the interleaved parallel flying-cross three-level bidirectional buck-boost converter charges each of the capacitors, includes: The on / off states of the pre-charge module, the first switch, and the fourth switch are controlled to charge the input-side support capacitor and the input-side flying capacitor in the H-bridge module. When the input-side support capacitor and the input-side flying capacitor have completed charging, the eighth switch is turned on; For at least one of the H-bridge modules, the on / off states of the first switch, the second switch, and the seventh switch are synchronously controlled based on the same PWM signal to charge the output-side flying capacitor and the output-side supporting capacitor.

3. The method according to claim 2, characterized in that, The pre-charging module includes a main switch, an auxiliary switch, and a resistor. The auxiliary switch and the resistor are connected in series and then in parallel across the main switch. Controlling the on / off states of the pre-charging module, the first switch, and the fourth switch to charge the input-side supporting capacitor and the input-side flying capacitor in the H-bridge module includes: The auxiliary switch, the first switch, and the fourth switch are turned on to enable charging of the input-side support capacitor and the input-side flying capacitor; When it is determined that the voltage across the input-side flying capacitor reaches the first target voltage, the first switch and the fourth switch corresponding to the input-side flying capacitor are turned off, while the auxiliary switch remains on. When the voltage across the input-side support capacitor reaches the second target voltage, the main circuit switch is turned on and the auxiliary switch is turned off.

4. The method according to claim 2, characterized in that, The method of synchronously controlling the on / off states of the first, second, and seventh switches based on the same PWM signal for at least one H-bridge module to charge the output-side flying capacitor and the output-side supporting capacitor includes: For each of the H-bridge modules, the eighth switch is kept on, and the on / off states of the first, second, and seventh switches are synchronously controlled based on the same PWM signal to charge the output-side support capacitor and the output-side flying capacitor through the inductor.

5. The method according to claim 4, characterized in that, After synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal, the method further includes: For each of the H-bridge modules, when the voltage across the output-side flying capacitor reaches the third target voltage, the on / off states of the first, second, seventh, and eighth switches are synchronously controlled based on the same PWM signal to continue charging the output-side support capacitor through the inductor.

6. The method according to claim 5, characterized in that, After synchronously controlling the on / off states of the first switch, the second switch, the seventh switch, and the eighth switch based on the same PWM signal, the method further includes: When the voltage across the output-side support capacitor reaches the fourth target voltage, the first, second, seventh, and eighth switches in all H-bridge modules are turned off.

7. The method according to claim 2, characterized in that, The two H-bridge modules are a first H-bridge module and a second H-bridge module, respectively; for at least one of the H-bridge modules, the on / off states of the first switch, the second switch, and the seventh switch are synchronously controlled based on the same PWM signal to charge the output-side flying capacitor and the output-side supporting capacitor, including: Turn on the fifth switch in the second H-bridge module, and keep the eighth switch in both the first H-bridge module and the second H-bridge module on. For the first H-bridge module, the on / off states of the first switch, the second switch, and the seventh switch are synchronously controlled based on the same PWM signal, so as to charge the output-side support capacitor and the output-side flying capacitor in the first H-bridge module and the second H-bridge module through the inductance of the first H-bridge module.

8. The method according to claim 7, characterized in that, After synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal, the method further includes: When the voltage across the flying capacitor on the output side of the second H-bridge module reaches the third target voltage, the fifth switch and / or the eighth switch in the second H-bridge module are turned off.

9. The method according to claim 8, characterized in that, After synchronously controlling the on / off states of the first switch, the second switch, and the seventh switch based on the same PWM signal, the method further includes: When the voltage across the flying capacitor on the output side in the first H-bridge module reaches the third target voltage, the on / off states of the first, second, seventh, and eighth switches in the first H-bridge module are synchronously controlled based on the same PWM signal, so as to continue charging the output-side support capacitor through the inductor in the first H-bridge module.

10. The method according to claim 9, characterized in that, When the voltage across the flying capacitor on the output side of both the first H-bridge module and the second H-bridge module reaches the third target voltage, the method further includes: When the voltage across the output-side support capacitor reaches the fourth target voltage, all the first, second, seventh, and eighth switches in the first H-bridge module are turned off.

11. The method according to claim 2, characterized in that, Before controlling the on / off states of the pre-charge module, the first switch, and the fourth switch, the method further includes: For each H-bridge module, the on / off states of the first switch, the second switch, the seventh switch and the eighth switch are synchronously controlled based on the first PWM signal, and the on / off states of the third switch, the fourth switch, the fifth switch and the sixth switch are synchronously controlled based on the second PWM signal. The first PWM signal and the second PWM signal are complementary PWM signals.

12. A controller, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, performs the pre-charging method for the interleaved parallel fly-through three-level bidirectional buck-boost converter as described in any one of claims 1 to 11.

13. An interleaved parallel flying three-level bidirectional buck-boost converter, characterized in that, Includes the controller as described in claim 12.

14. A power supply device, characterized in that, Includes the interleaved parallel flying three-level bidirectional buck-boost converter as described in claim 13.

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