Bidirectional power conversion device, bidirectional power supply and vehicle

Abstract

The application relates to a bidirectional power conversion device, a bidirectional power supply and a vehicle, and relates to the technical field of power supply control. The bidirectional power conversion device comprises a first capacitor, a slow-starting circuit and a switching circuit. The first capacitor is connected with a first power port; the slow-starting circuit is used for outputting a starting voltage; the switching circuit is connected with the first capacitor and the slow-starting circuit, is used for controlling the first capacitor and the slow-starting circuit to be in communication, and is used for pre-charging the first capacitor according to the starting voltage output by the slow-starting circuit, so that the first capacitor transmits a first power voltage input by the first power port after pre-charging. Since the voltage of the first capacitor is close to the first power voltage after pre-charging, the voltage change rate of the first capacitor is small at the moment when the first power voltage is input into the first capacitor, and no instantaneous large current is generated, so that the stability of the bidirectional power supply is improved.

Description

Technical Field

[0001] This application relates to the field of power control technology, and in particular to a bidirectional power conversion device, a bidirectional power supply, and a vehicle. Background Technology

[0002] The bidirectional power conversion device is used to realize the bidirectional flow and conversion of electrical energy between two power sources. When one power module in a dual power system fails or has insufficient power, it can quickly switch to the other power module for power supply, thereby effectively avoiding downtime or abnormal operation caused by power problems and improving the stability and reliability of power supply.

[0003] Currently, a port capacitor is typically placed between the bidirectional power converter and the power supply to filter the output voltage transmitted to the bidirectional power converter, thereby improving the power quality. However, since the initial voltage of the port capacitor is zero at this time, and the current of the port capacitor is related to the rate of voltage change, a large instantaneous current will appear in the port capacitor at the moment the output voltage is connected, which can easily damage the circuit and improve the stability of the bidirectional power supply operation. Utility Model Content

[0004] This application provides a bidirectional power conversion device that improves the stability of bidirectional power supply operation, thereby at least partially solving the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a bidirectional power conversion device is provided, comprising:

[0006] The first capacitor is connected to the first power supply port;

[0007] A soft-start circuit is used to output the startup voltage;

[0008] A switching circuit, connected to the first capacitor and the soft-start circuit, is used to control the connection between the first capacitor and the soft-start circuit, so that the first capacitor is pre-charged according to the start-up voltage output by the soft-start circuit, so that the first capacitor transmits the first power supply voltage connected to the first power port after pre-charging.

[0009] Optionally, a second capacitor and a voltage conversion circuit may also be included;

[0010] The second capacitor is connected to the second power port for transmitting the second power supply voltage;

[0011] The voltage conversion circuit is connected to the first capacitor and the second capacitor, and is used to convert the first power supply voltage into a first conversion voltage with the same amplitude as the second power supply voltage, or to convert the second power supply voltage into a second conversion voltage with the same amplitude as the first power supply voltage.

[0012] Optionally, it also includes an anti-backflow circuit, connected to the first power port, the second power port and the voltage conversion circuit, for controlling the connection and disconnection of the line between the first power port and the voltage conversion circuit, and the connection and disconnection of the line between the second power port and the voltage conversion circuit.

[0013] Optionally, the backflow prevention circuit includes a first switching transistor and a second switching transistor;

[0014] The first switching transistor includes a first electrode connected to the first power port, a second electrode connected to the voltage conversion circuit and the first capacitor, and a control electrode connected to the first on / off control signal;

[0015] The second switching transistor includes a first electrode connected to the second power supply port, a second electrode connected to the voltage conversion circuit and the second capacitor, and a control electrode connected to the second on / off control signal.

[0016] Optionally, the switching circuit includes a switching device, which includes a first terminal connected to the soft-start circuit and a second terminal connected to the first capacitor.

[0017] Optionally, the soft-start circuit includes a driver sub-circuit, a transformer, and a rectifier sub-circuit;

[0018] The driving sub-circuit is connected to the voltage source and the primary side of the transformer, and is used to convert the output voltage of the voltage source and output it to the primary side of the transformer, so that the primary side of the transformer can transfer energy to the secondary side.

[0019] The rectifier circuit is connected to the secondary side of the transformer and the switching circuit, and is used to rectify the energy transmitted on the secondary side of the transformer to obtain the starting voltage.

[0020] Optionally, the primary side of the transformer is connected to a reference voltage at the first terminal, the primary side is connected to the drive sub-circuit, and the secondary side is connected to the rectifier sub-circuit at the first and second terminals.

[0021] Optionally, it also includes a voltage divider circuit connected to the voltage source and the transformer, used to generate the reference voltage based on the output voltage of the voltage source;

[0022] The voltage divider circuit includes a third capacitor and a fourth capacitor;

[0023] The first terminal of the third capacitor is connected to the positive terminal of the voltage source, and the second terminal is connected to the fourth capacitor and the first terminal of the primary side of the transformer.

[0024] The first terminal of the fourth capacitor is connected to the first terminal of the primary side of the third capacitor and the transformer, and the second terminal is connected to the negative terminal of the voltage source.

[0025] Optionally, the driving sub-circuit includes a third switch and a fourth switch;

[0026] The third switch includes a first electrode connected to the positive terminal of the voltage source, a second electrode connected to the first electrode of the fourth switch and the transformer, and a control electrode connected to the first drive signal;

[0027] The fourth switching transistor also includes a second electrode connected to the negative terminal of the voltage source and a control electrode connected to the second drive signal.

[0028] Optionally, the rectifier circuit includes a first diode and a second diode;

[0029] The first diode includes an anode connected to a first terminal of the secondary side of the transformer and a cathode connected to the switching circuit;

[0030] The second diode includes an anode connected to the second terminal of the secondary side of the transformer and a cathode connected to the switching circuit.

[0031] Optionally, it may also include sampling circuitry and a controller;

[0032] The sampling circuit is connected to the first power port and the first capacitor, and is used to sample the first power supply voltage and the first voltage value of the first capacitor when the line between the first power port and the first capacitor is disconnected.

[0033] The controller is connected to the sampling circuit and is used to generate a first pre-charge start signal based on the difference between the first voltage value and the first power supply voltage, and output the first pre-charge start signal to the switching circuit so as to control the conduction between the first capacitor and the soft start circuit through the switching circuit.

[0034] Optionally, the sampling circuit is connected to the second power port and the second capacitor, and is used to sample the second power supply voltage and the second voltage value of the second capacitor when the line between the second power port and the second capacitor is disconnected.

[0035] The controller is used to generate a second pre-charge start signal based on the difference between the second voltage value and the second power supply voltage, and output the second pre-charge start signal to the voltage conversion circuit so that the voltage conversion circuit pre-charges the second capacitor according to the first power supply voltage.

[0036] According to a second aspect of this application, a bidirectional power supply is provided, including a first voltage source, a second voltage source, and the aforementioned bidirectional power conversion device;

[0037] The first voltage source is connected to the first power port and is used to output the first power voltage to the first power port;

[0038] The second voltage source is connected to the second power port and is used to output the second power supply voltage to the second power port.

[0039] According to a third aspect of this application, a vehicle is provided, including the aforementioned bidirectional power supply.

[0040] In summary, in the bidirectional power conversion device of this application embodiment, the connection between the first capacitor and the soft-start circuit is first controlled by the switching circuit, and then the soft-start circuit outputs the start-up voltage and transmits the start-up voltage to the first capacitor to pre-charge the first capacitor. Since the voltage of the first capacitor is close to the first power supply voltage after pre-charging, the voltage change rate of the first capacitor is small at the moment the first power supply voltage is connected to the first capacitor, and no instantaneous large current is generated, thereby improving the stability of the bidirectional power supply operation.

[0041] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0044] Figure 1 This is a schematic diagram of a bidirectional power conversion device provided in an exemplary embodiment of this disclosure;

[0045] Figure 2 This is a schematic diagram of a voltage conversion circuit provided in an exemplary embodiment of this disclosure;

[0046] Figure 3 This is a circuit diagram of the anti-backflow circuit provided in an exemplary embodiment of this disclosure;

[0047] Figure 4 This is a circuit diagram of a bidirectional power conversion device provided in an exemplary embodiment of this disclosure;

[0048] Figure 5 This is a schematic diagram of the sampling circuit and controller provided in an exemplary embodiment of this disclosure.

[0049] Explanation of reference numerals in the attached diagram: 1. Soft start circuit; 11. Driver sub-circuit; 12. Rectifier sub-circuit; 13. Voltage divider sub-circuit; 2. Switching circuit; 3. Voltage conversion circuit; 4. Anti-backflow circuit; 5. Sampling circuit; 6. Controller. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0051] According to the first aspect of this application, referring to Figure 1 This disclosure provides a bidirectional power conversion device, including a first capacitor C1, a soft-start circuit 1, and a switching circuit 2. The first capacitor C1 is connected to a first power port; the soft-start circuit 1 outputs a startup voltage; the switching circuit 2 is connected to both the first capacitor C1 and the soft-start circuit 1, and controls the connection between them, causing the first capacitor C1 to pre-charge according to the startup voltage output by the soft-start circuit 1, so that after pre-charging, the first capacitor C1 transmits the first power voltage connected to the first power port.

[0052] Wherein, the first capacitor C1 is the port capacitance of the first power supply port, used to filter and transmit the first power supply voltage.

[0053] As an example, the current through a capacitor can be expressed as: I = C (dV / dt); where dV / dt represents the rate of change of voltage; C represents the capacitance, which is a fixed value; therefore, the greater the rate of change of voltage across the capacitor, the greater the current. If the first capacitor C1 is not pre-charged, its voltage is zero. If the first power supply voltage is directly applied to C1, the rate of change of voltage across C1 equals the first power supply voltage, easily resulting in a large instantaneous current. However, if C1 is pre-charged to maintain its voltage at the pre-charge voltage, and then the first power supply voltage is applied, the rate of change of voltage across C1 equals the difference between the first power supply voltage and the pre-charge voltage, reducing the rate of change of voltage across C1 and thus decreasing the current accordingly.

[0054] In the above embodiment, the connection between the first capacitor C1 and the soft-start circuit 1 is first controlled by the switching circuit 2. Then, the soft-start circuit 1 outputs the starting voltage and transmits the starting voltage to the first capacitor C1 to precharge the first capacitor C1. Since the voltage of the first capacitor C1 is close to the first power supply voltage after precharging, the voltage change rate of the first capacitor C1 is small at the moment the first power supply voltage is connected to the first capacitor C1, and no instantaneous large current is generated, thereby improving the stability of the bidirectional power supply operation.

[0055] Reference Figure 2 In some embodiments, the bidirectional power conversion device further includes a second capacitor C2 and a voltage conversion circuit 3. The second capacitor C2 is connected to a second power port for transmitting a second power supply voltage; the voltage conversion circuit 3 is connected to the first capacitor C1 and the second capacitor C2 for converting the first power supply voltage into a first conversion voltage with the same amplitude as the second power supply voltage, or converting the second power supply voltage into a second conversion voltage with the same amplitude as the first power supply voltage.

[0056] Reference Figure 2 As an example, a bidirectional power conversion device can be applied to a bidirectional power supply. The bidirectional power supply also includes a first voltage source for outputting a first power supply voltage and a second voltage source for outputting a second power supply voltage. VCC1 represents the first voltage source, and VCC2 represents the second voltage source. The amplitudes of the first and second power supply voltages are different; the amplitude of the first power supply voltage can be greater than that of the second power supply voltage. For example, the amplitude of the first voltage source outputting the first voltage source can be 48V, and the amplitude of the second voltage source can be 12V. When both the first and second voltage sources are working normally (no insufficient output power occurs), the voltage conversion circuit 3 does not work, and there is no voltage input at either the first or second power supply port. At this time, the first voltage source supplies power to the first load connected to it, and the second voltage source supplies power to the second load connected to it.

[0057] As an example, the second capacitor C2 is the port capacitor of the second power supply port, used to filter the second power supply voltage and transmit it to the voltage conversion circuit 3. Simultaneously, it filters the first converted voltage output from the voltage conversion circuit 3 and outputs the filtered first converted voltage to the second load. The first capacitor C1 is also used to filter the second converted voltage output from the voltage conversion circuit 3 and output the filtered second converted voltage to the first load. Thus, bidirectional transmission of the first and second power supply voltages can be achieved through the voltage conversion circuit 3, the first capacitor C1, and the second capacitor C2.

[0058] Reference Figure 3In some embodiments, the bidirectional power conversion device further includes an anti-backflow circuit 4, which is connected to the first power port, the second power port and the voltage conversion circuit 3, and is used to control the connection and disconnection of the line between the first power port and the voltage conversion circuit 3, as well as the connection and disconnection of the line between the second power port and the voltage conversion circuit 3.

[0059] In some embodiments, the anti-backflow circuit 4 includes a first switch Q1 and a second switch Q2. The first switch Q1 includes a first electrode connected to a first power supply port, a second electrode connected to the voltage conversion circuit 3 and the first capacitor C1, and a control electrode connected to a first on / off control signal; the second switch Q2 includes a first electrode connected to a second power supply port, a second electrode connected to the voltage conversion circuit 3 and the second capacitor C2, and a control electrode connected to a second on / off control signal.

[0060] As an example, since the voltage conversion circuit 3 does not need to work when the first voltage source and the second voltage source are working normally, the first switch Q1 can be turned off to prevent the first power supply voltage from flowing back to the voltage conversion circuit 3 through the first power supply port. At the same time, the second switch Q2 can be turned off to prevent the second power supply voltage from flowing back to the voltage conversion circuit through the second power supply port.

[0061] In some embodiments, the switching circuit 2 includes a switching device K1, which includes a first end connected to the soft-start circuit 1 and a second end connected to the first capacitor C1.

[0062] Reference Figure 4 In some embodiments, the soft-start circuit 1 can be a half-bridge drive circuit. For example, the soft-start circuit 1 includes a drive sub-circuit 11, a transformer T1, and a rectifier sub-circuit 12. The drive sub-circuit 11 is connected to the voltage source and the primary side of the transformer T1, and is used to convert the output voltage of the voltage source and output it to the primary side of the transformer T1, so that the primary side of the transformer T1 can transfer energy to the secondary side. The rectifier sub-circuit 12 is connected to the secondary side of the transformer T1 and the switching circuit 2, and is used to rectify the energy transferred to the secondary side of the transformer T1 to obtain the start-up voltage.

[0063] As an example, the first terminal of the primary side of transformer T1 is connected to a reference voltage, the second terminal of the primary side is connected to the drive sub-circuit 11, and the first and second terminals of the secondary side are connected to the rectifier sub-circuit 12.

[0064] In some embodiments, the soft-start circuit 1 further includes a voltage divider circuit 13 connected to the voltage source and the transformer T1, for generating a reference voltage based on the output voltage of the voltage source; the voltage divider circuit 13 includes a third capacitor C3 and a fourth capacitor C4; the first terminal of the third capacitor C3 is connected to the positive terminal of the voltage source, and the second terminal is connected to the fourth capacitor C4 and the first terminal of the primary side of the transformer T1; the first terminal of the fourth capacitor C4 is connected to the third capacitor C3 and the first terminal of the primary side of the transformer T1, and the second terminal is connected to the negative terminal of the voltage source.

[0065] As an example, the output voltage of the voltage source is divided by the third capacitor C3 and the fourth capacitor C4 to obtain a reference voltage. Taking the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 as equal, the reference voltage is equal to half of the output voltage. At the same time, the third capacitor C3 and the fourth capacitor C4 can also filter out high-frequency noise in the output voltage.

[0066] In some embodiments, the driving sub-circuit 11 includes a third switch Q3 and a fourth switch Q4. The third switch Q3 includes a first electrode connected to the positive terminal of the voltage source, a second electrode connected to the first electrode of the fourth switch Q4 and the transformer T1, and a control electrode connected to the first driving signal; the fourth switch Q4 also includes a second electrode connected to the negative terminal of the voltage source and a control electrode connected to the second driving signal.

[0067] In some embodiments, the rectifier circuit 12 includes a first diode D1 and a second diode D2. The first diode D1 includes an anode connected to a first terminal of the secondary side of the transformer T1 and a cathode connected to the switching circuit 2; the second diode D2 includes an anode connected to a second terminal of the secondary side of the transformer T1 and a cathode connected to the switching circuit 2.

[0068] As an example, the soft-start circuit 1 also includes an output inductor and a fifth capacitor, which together form a filter network. The third switch Q3 and the fourth switch Q4 form a half-bridge structure. Through the alternating conduction of the third switch Q3 and the fourth switch Q4, a voltage is applied to the primary side of transformer T1. The transformer T1 then outputs the energy from the primary side to the secondary side. The first diode D1 and the second diode D2 form a full-wave rectifier structure, converting the alternating voltage output from the secondary side of transformer T1 into pulsating DC. The output inductor and capacitor form a filter network, which smooths the pulsating DC, thereby outputting a smooth and stable start-up voltage for pre-charging the first capacitor C1.

[0069] Reference Figure 5In some embodiments, the bidirectional power conversion device further includes a sampling circuit 5 and a controller 6. The sampling circuit 5 is connected to the first power port and the first capacitor C1, and is used to sample the first power supply voltage and the first voltage value of the first capacitor C1 when the line between the first power port and the first capacitor C1 is disconnected. The controller 6 is connected to the sampling circuit 5, and is used to generate a first pre-charge start signal based on the difference between the first voltage value and the first power supply voltage, and output the first pre-charge start signal to the switching circuit 2, so as to control the conduction between the first capacitor C1 and the soft-start circuit 1 through the switching circuit 2.

[0070] In some embodiments, the sampling circuit 5 is connected to the second power port and the second capacitor C2, and is used to sample the second power supply voltage and the second voltage value of the second capacitor C2 when the line between the second power supply port and the second capacitor C2 is disconnected; the controller 6 is used to generate a second pre-charge start signal based on the difference between the second voltage value and the second power supply voltage, and output the second pre-charge start signal to the voltage conversion circuit 3, so that the voltage conversion circuit 3 pre-charges the second capacitor C2 according to the first power supply voltage.

[0071] In the above embodiment, firstly, the sampling circuit 5 samples the voltages between the first power port and the first capacitor C1, and between the second power port and the second capacitor C2, respectively. Then, the controller 6 calculates the difference between the first voltage value and the first power supply voltage, and the difference between the second voltage value and the second power supply voltage, to determine whether the first capacitor C1 and the second capacitor C2 need to be pre-charged, and generates corresponding first and second pre-charge start signals. The first pre-charge start signal controls the switching circuit 2 to enable the first capacitor C1 to conduct with the soft-start circuit 1, so that the first capacitor C1 pre-charges according to the start voltage output by the soft-start circuit 1. After the first capacitor C1 is pre-charged, the first power supply voltage can be output to the voltage conversion circuit 3 without instantaneous large current due to the high voltage change rate of the first capacitor C1. At this time, the second pre-charge start signal controls the voltage conversion circuit 3 to pre-charge the second capacitor C2 according to the first power supply voltage, thereby realizing the pre-charging of the second capacitor C2. In this way, the pre-charging of the first capacitor C1 and the second capacitor C2 can be realized by setting only one set of switching circuit 2 and soft-start circuit 1, which is simple in structure and low in cost.

[0072] Reference Figure 5 This disclosure exemplarily describes the operation of a bidirectional power conversion device:

[0073] When the first voltage source and the second voltage source are working normally and there is no insufficient output power, the first power supply voltage output by the first voltage source supplies power to the first load, and the second power supply voltage output by the second voltage source supplies power to the second load. At this time, the first switch Q1 and the second switch Q2 in the anti-backflow circuit 4 are disconnected, the switching circuit 2 is disconnected, and the soft start circuit 1 and the voltage conversion circuit 3 do not work.

[0074] When insufficient output power of the second voltage source is detected, the sampling circuit 5 first samples the first voltage value of the first capacitor C1 and the first power supply voltage output by the first voltage source. The controller 6 determines whether the difference between the first voltage value and the first power supply voltage is greater than a preset voltage value. If it is greater than the preset voltage value, the controller 6 outputs a first pre-charge start signal to the switching circuit 2 to control the switching device K1 to close. At the same time, it controls the soft start circuit 1 to start working and output a start voltage so that the first capacitor C1 can be pre-charged using the start voltage. When the difference between the first voltage value and the first power supply voltage is less than or equal to the preset voltage value, the soft start circuit 1 stops working and the switching device K1 is opened. The pre-charging of the first capacitor C1 is completed. At this time, the controller 6 outputs a first on / off control signal to control the first switch Q1 in the anti-backflow circuit 4 to turn on, so that the first voltage source is transmitted to the voltage conversion circuit 3 after being filtered by the first capacitor C1.

[0075] Then, the sampling circuit 5 samples the second voltage value of the second capacitor C2 and the second power supply voltage output by the first voltage source. The controller 6 determines whether the difference between the second voltage value and the second power supply voltage is greater than a preset voltage value. If it is greater than the preset voltage value, the controller 6 outputs a second pre-charge start signal to the voltage conversion circuit 3, so that the voltage conversion circuit 3 converts the first power supply voltage into the pre-charge voltage of the second capacitor C2, thereby pre-charging the second capacitor C2 until the difference between the second voltage value and the second power supply voltage is less than or equal to the preset voltage value, and the pre-charging of the second capacitor C2 is completed.

[0076] Finally, after the first capacitor C1 and the second capacitor C2 have been pre-charged, the controller 6 outputs the first on / off control signal and the second on / off control signal, respectively controlling the first switch Q1 and the second switch Q2 to be turned on simultaneously, and controlling the voltage conversion module to convert the first power supply voltage into a second conversion voltage with the same amplitude as the second power supply voltage, so that the second load can be powered by the second conversion voltage and the second power supply voltage together, so as to avoid the second load from failing to work properly due to insufficient power of the second power supply voltage.

[0077] Similarly, when insufficient output power of the first voltage source is detected, the pre-charging process of the first capacitor C1 and the second capacitor C2 is the same. The difference is that after both the first capacitor C1 and the second capacitor C2 have been pre-charged, the controller 6 outputs a first on / off control signal and a second on / off control signal, respectively controlling the first switch Q1 and the second switch Q2 to conduct simultaneously, and controlling the voltage conversion module to convert the second power supply voltage into a first conversion voltage with the same amplitude as the first power supply voltage, so that the first load is powered by the first conversion voltage and the second power supply voltage together, so as to avoid the first load failing to work properly due to insufficient power of the first power supply voltage.

[0078] According to a second aspect of this application, a bidirectional power supply is provided, including a first voltage source, a second voltage source, and the aforementioned bidirectional power conversion device. The first voltage source is connected to a first power port and is used to output a first power voltage to the first power port; the second voltage source is connected to a second power port and is used to output a second power voltage to the second power port.

[0079] According to a second aspect of this disclosure, a bidirectional power supply is provided, which includes the bidirectional power conversion device described above. This bidirectional power supply possesses all the beneficial effects of the bidirectional power conversion device described above, which will not be elaborated further herein.

[0080] According to a third aspect of this application, a vehicle is provided, including the aforementioned bidirectional power supply.

[0081] The vehicle may be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this disclosure does not make any specific restrictions.

[0082] In the description of this application, 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 number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0083] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0084] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0085] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A bidirectional power conversion device, characterized by, include: The first capacitor is connected to the first power supply port; A soft-start circuit is used to output the startup voltage; A switching circuit, connected to the first capacitor and the soft-start circuit, is used to control the connection between the first capacitor and the soft-start circuit, so that the first capacitor is pre-charged according to the start-up voltage output by the soft-start circuit, so that the first capacitor transmits the first power supply voltage connected to the first power port after pre-charging.

2. The bidirectional power conversion device of claim 1, wherein, It also includes a second capacitor and a voltage conversion circuit; The second capacitor is connected to the second power port for transmitting the second power supply voltage; The voltage conversion circuit is connected to the first capacitor and the second capacitor, and is used to convert the first power supply voltage into a first conversion voltage with the same amplitude as the second power supply voltage, or to convert the second power supply voltage into a second conversion voltage with the same amplitude as the first power supply voltage.

3. The bidirectional power conversion device of claim 2, wherein, It also includes an anti-backflow circuit, which is connected to the first power port, the second power port and the voltage conversion circuit, and is used to control the connection and disconnection of the line between the first power port and the voltage conversion circuit, as well as the connection and disconnection of the line between the second power port and the voltage conversion circuit.

4. The bidirectional power conversion device of claim 3, wherein, The backflow prevention circuit includes a first switching transistor and a second switching transistor; The first switching transistor includes a first electrode connected to the first power port, a second electrode connected to the voltage conversion circuit and the first capacitor, and a control electrode connected to the first on / off control signal; The second switching transistor includes a first electrode connected to the second power supply port, a second electrode connected to the voltage conversion circuit and the second capacitor, and a control electrode connected to the second on / off control signal.

5. The bidirectional power conversion device of claim 4, wherein, The switching circuit includes a switching device, which includes a first terminal connected to the soft-start circuit and a second terminal connected to the first capacitor.

6. The bidirectional power conversion device of claim 2, wherein, The soft-start circuit includes a driver sub-circuit, a transformer, and a rectifier sub-circuit. The driving sub-circuit is connected to the voltage source and the primary side of the transformer, and is used to convert the output voltage of the voltage source and output it to the primary side of the transformer, so that the primary side of the transformer can transfer energy to the secondary side. The rectifier circuit is connected to the secondary side of the transformer and the switching circuit, and is used to rectify the energy transmitted on the secondary side of the transformer to obtain the starting voltage.

7. The bidirectional power conversion device of claim 6, wherein, The primary side of the transformer is connected to a reference voltage at the first terminal, the primary side is connected to the drive sub-circuit at the second terminal, and the secondary side is connected to the rectifier sub-circuit at the first and second terminals.

8. The bidirectional power conversion device of claim 7, wherein, It also includes a voltage divider circuit connected to the voltage source and the transformer, used to generate the reference voltage based on the output voltage of the voltage source; The voltage divider circuit includes a third capacitor and a fourth capacitor; The first terminal of the third capacitor is connected to the positive terminal of the voltage source, and the second terminal is connected to the fourth capacitor and the first terminal of the primary side of the transformer. The first terminal of the fourth capacitor is connected to the first terminal of the primary side of the third capacitor and the transformer, and the second terminal is connected to the negative terminal of the voltage source.

9. The bidirectional power conversion device of claim 7, wherein, The driving sub-circuit includes a third switch and a fourth switch; The third switch includes a first electrode connected to the positive terminal of the voltage source, a second electrode connected to the first electrode of the fourth switch and the transformer, and a control electrode connected to the first drive signal; The fourth switching transistor also includes a second electrode connected to the negative terminal of the voltage source and a control electrode connected to the second drive signal.

10. The bidirectional power conversion device of claim 7, wherein, The rectifier circuit includes a first diode and a second diode; The first diode includes an anode connected to a first terminal of the secondary side of the transformer and a cathode connected to the switching circuit; The second diode includes an anode connected to the second terminal of the secondary side of the transformer and a cathode connected to the switching circuit.

11. The bidirectional power conversion device of claim 2, wherein, It also includes sampling circuitry and a controller; The sampling circuit is connected to the first power port and the first capacitor, and is used to sample the first power supply voltage and the first voltage value of the first capacitor when the line between the first power port and the first capacitor is disconnected. The controller is connected to the sampling circuit and is used to generate a first pre-charge start signal based on the difference between the first voltage value and the first power supply voltage, and output the first pre-charge start signal to the switching circuit so as to control the conduction between the first capacitor and the soft start circuit through the switching circuit.

12. The bidirectional power conversion device of claim 11, wherein, The sampling circuit is connected to the second power port and the second capacitor, and is used to sample the second power supply voltage and the second voltage value of the second capacitor when the line between the second power port and the second capacitor is disconnected. The controller is used to generate a second pre-charge start signal based on the difference between the second voltage value and the second power supply voltage, and output the second pre-charge start signal to the voltage conversion circuit so that the voltage conversion circuit pre-charges the second capacitor according to the first power supply voltage.

13. A bidirectional power supply, characterized by Includes a first voltage source, a second voltage source, and a bidirectional power conversion device as described in any one of claims 2 to 12; The first voltage source is connected to the first power port and is used to output the first power voltage to the first power port; The second voltage source is connected to the second power port and is used to output the second power supply voltage to the second power port.

14. A vehicle characterized by comprising: Includes the bidirectional power supply as described in claim 13.

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