Pre-charging system and vehicle
By introducing an independent flyback circuit into the DC-DC converter, the problem of low reverse precharge efficiency is solved, achieving efficient reverse precharge at low power, reducing the size of the DC-DC converter and improving space utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHINRY TECH
- Filing Date
- 2025-04-15
- Publication Date
- 2026-05-12
AI Technical Summary
Existing DC-DC converters have low reverse pre-charge circuit efficiency, occupy a large space when integrated into the DC-DC converter, and are not efficient at low power.
Design an independent flyback circuit to achieve reverse pre-charging through a separate layout between the high-voltage DC connector and the low-voltage DC connector. This includes the connection method of the high-voltage battery, low-voltage battery, flyback circuit, first capacitor and DC connector, which improves the reverse pre-charging efficiency.
It improves reverse pre-charge efficiency at low power, reduces the size of the DC-DC converter, increases space utilization, and ensures the vehicle's waterproof and dustproof performance.
Smart Images
Figure CN224233354U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic circuit technology, specifically to a pre-charging system and a vehicle. Background Technology
[0002] DC-DC converters are key components of the electrical systems of new energy vehicles. The reverse pre-charge function of DC-DC converters is generally achieved through a reverse pre-charge circuit. Currently, the reverse pre-charge circuit is usually integrated into the DC-DC converter, resulting in low reverse pre-charge efficiency. Utility Model Content
[0003] This application provides a pre-charging system and vehicle that can improve reverse pre-charging efficiency.
[0004] A first aspect of this application provides a pre-charge system, including a high-voltage battery, a high-voltage DC connector, a flyback circuit, a low-voltage DC connector, a first capacitor, and a low-voltage battery; the positive terminal of the high-voltage battery is connected to a first terminal of the high-voltage DC connector, the negative terminal of the high-voltage battery is connected to a second terminal of the high-voltage DC connector, the third terminal of the high-voltage DC connector is connected to a first terminal of the flyback circuit and the positive terminal of the first capacitor, the fourth terminal of the high-voltage DC connector is connected to a second terminal of the flyback circuit and the negative terminal of the first capacitor, the positive terminal of the low-voltage battery is connected to a first terminal of the low-voltage DC connector, the negative terminal of the low-voltage battery is connected to a second terminal of the low-voltage DC connector, the third terminal of the low-voltage DC connector is connected to a third terminal of the flyback circuit, and the fourth terminal of the low-voltage DC connector is connected to a fourth terminal of the flyback circuit;
[0005] The flyback circuit is used to precharge the first capacitor from the low-voltage battery.
[0006] In this embodiment, the high-voltage DC connector is the interface connecting the high-voltage battery and the flyback circuit, while the low-voltage DC connector is the interface connecting the low-voltage battery and the flyback circuit. The high-voltage and low-voltage DC connectors allow for good compatibility between the DC-DC converter and the vehicle, ensuring good waterproof and dustproof performance.
[0007] Flyback circuits are highly efficient at low power levels (e.g., below 400W), and their efficiency is higher than that of integrating a reverse precharge circuit in a DC-DC converter. The reverse precharge power of a flyback circuit is typically around 100W. By employing the precharge system of this application embodiment, the reverse precharge efficiency can be improved.
[0008] Optionally, the flyback circuit includes: a first transformer module, a first switching transistor, and a first diode; the first end of the primary winding of the first transformer module is connected to the third end of the low-voltage DC connector, the second end of the primary winding of the first transformer module is connected to the first end of the first switching transistor, the second end of the first switching transistor is connected to the fourth end of the low-voltage DC connector, the first end of the secondary winding of the first transformer module is connected to the anode of the first diode, the cathode of the first diode is connected to the third end of the high-voltage DC connector, and the second end of the secondary winding of the first transformer module is connected to the fourth end of the high-voltage DC connector.
[0009] In this embodiment, the flyback circuit has a simple structure. When the first switch is in the on state, the flyback circuit realizes the pre-charge function and can control the low-voltage battery to pre-charge the first capacitor.
[0010] Optionally, the first transformer module includes a first transformer or a first current transformer.
[0011] In this embodiment, the first transformer module can be implemented using a first transformer or a first instrument transformer. The first instrument transformer may include a voltage transformer or a current transformer.
[0012] Optionally, the flyback circuit includes: a second transformer module, a second switching transistor, a third switching transistor, a second diode, a third diode, a fourth diode, a first inductor, and a second inductor; the first terminal of the second switching transistor is connected to the negative terminal of the second diode and the third terminal of the low-voltage DC connector; the second terminal of the second switching transistor is connected to the first terminal of the first inductor and the negative terminal of the third diode; the second terminal of the first inductor is connected to the first terminal of the second inductor and the first terminal of the primary winding of the second transformer module; the positive terminal of the second diode is connected to the first terminal of the third switching transistor, the second terminal of the second inductor, and the second terminal of the primary winding of the second transformer module; the second terminal of the third switching transistor is connected to the positive terminal of the third diode and the fourth terminal of the low-voltage DC connector; the first terminal of the secondary winding of the second transformer module is connected to the positive terminal of the fourth diode; the negative terminal of the fourth diode is connected to the third terminal of the high-voltage DC connector; and the second terminal of the secondary coil of the second transformer module is connected to the fourth terminal of the high-voltage DC connector.
[0013] In this embodiment, the flyback circuit is a dual-switch flyback circuit, which controls the on or off of two switching transistors (the second switching transistor and the third switching transistor) to achieve pre-charging of the low-voltage battery to the first capacitor.
[0014] Optionally, the second transformer module includes a second transformer or a second current transformer.
[0015] In this embodiment, the second transformer module can be implemented using a second transformer or a second instrument transformer. The second instrument transformer may include a voltage transformer or a current transformer.
[0016] Optionally, the flyback circuit includes: a third transformer module, a fourth switching transistor, a fifth diode, a sixth diode, a second capacitor, and a first resistor; the first end of the first resistor is connected to the first end of the second capacitor, the first end of the primary winding of the third transformer module, and the third end of the low-voltage DC connector; the second end of the first resistor is connected to the second end of the second capacitor and the negative terminal of the fifth diode; the positive terminal of the fifth diode is connected to the second end of the primary winding of the third transformer module and the first end of the fourth switching transistor; the second end of the fourth switching transistor is connected to the fourth end of the low-voltage DC connector; the first end of the secondary winding of the third transformer module is connected to the positive terminal of the sixth diode; the negative terminal of the sixth diode is connected to the third end of the high-voltage DC connector; and the second end of the secondary winding of the third transformer module is connected to the fourth end of the high-voltage DC connector.
[0017] In this embodiment, the flyback circuit is an RCD clamp flyback circuit. The first resistor, second capacitor, and fifth diode of the RCD clamp flyback circuit serve as RCD clamps. The RCD clamp flyback circuit can suppress voltage spikes and prevent excessively high voltages between the first and second terminals of the fourth switching transistor in the circuit, thereby preventing the fourth switching transistor from being damaged due to excessive voltage.
[0018] Optionally, the third transformer module includes a third transformer or a third current transformer.
[0019] In this embodiment, the third transformer module can be implemented using a third transformer or a third instrument transformer. The third instrument transformer may include a voltage transformer or a current transformer.
[0020] Optionally, the flyback circuit includes: a fourth transformer module, a fifth switching transistor, a sixth switching transistor, a seventh diode, a third capacitor, and a third inductor; the first terminal of the third capacitor is connected to the first terminal of the third inductor, the first terminal of the primary winding of the fourth transformer module, and the third terminal of the low-voltage DC connector; the second terminal of the third capacitor is connected to the first terminal of the fifth switching transistor; the second terminal of the fifth switching transistor is connected to the second terminal of the third inductor, the first terminal of the sixth switching transistor, and the second terminal of the primary winding of the fourth transformer module; the second terminal of the sixth switching transistor is connected to the fourth terminal of the low-voltage DC connector; the first terminal of the secondary winding of the fourth transformer module is connected to the anode of the seventh diode; the cathode of the seventh diode is connected to the third terminal of the high-voltage DC connector; and the second terminal of the secondary coil of the fourth transformer module is connected to the fourth terminal of the high-voltage DC connector.
[0021] In this embodiment, the flyback circuit is an active clamp flyback circuit. When the sixth switch is turned on, the input energy is stored in the primary winding of the fourth transformer module. After the sixth switch is turned off, the energy of the primary winding of the fourth transformer module is fed back to the third terminal of the low-voltage DC connector through the fifth switch and the third capacitor, thereby suppressing voltage spikes and achieving soft switching.
[0022] Optionally, the fourth transformer module includes a fourth transformer or a fourth current transformer.
[0023] In this embodiment, the fourth transformer module can be implemented using a fourth transformer or a fourth instrument transformer. The fourth instrument transformer may include a voltage transformer or a current transformer.
[0024] Optionally, the high-voltage battery and the low-voltage battery are located on the same side of the vehicle.
[0025] In this embodiment, when both the high-voltage battery and the low-voltage battery are on the same side of the vehicle, an extra space can be provided on the other side of the vehicle to house the flyback circuit, thereby making full use of the space on the same side and increasing space utilization.
[0026] Optionally, the power of the flyback circuit is less than a set threshold.
[0027] In this embodiment, the threshold value can be preset. For example, the threshold value can be set to 400W. When the power of the flyback circuit is less than the threshold value, the efficiency of the flyback circuit is higher than that of integrating a reverse precharge circuit in a DC-DC converter, thereby improving the reverse precharge efficiency.
[0028] A second aspect of this application provides a vehicle including the pre-charging system described in any of the first aspects of this application.
[0029] The pre-charge system of this application embodiment includes a high-voltage battery, a high-voltage DC connector, a flyback circuit, a low-voltage DC connector, a first capacitor, and a low-voltage battery. The positive terminal of the high-voltage battery is connected to the first terminal of the high-voltage DC connector, the negative terminal of the high-voltage battery is connected to the second terminal of the high-voltage DC connector, the third terminal of the high-voltage DC connector is connected to the first terminal of the flyback circuit and the positive terminal of the first capacitor, and the fourth terminal of the high-voltage DC connector is connected to the second terminal of the flyback circuit and the negative terminal of the first capacitor. The positive terminal of the low-voltage battery is connected to the first terminal of the low-voltage DC connector, the negative terminal of the low-voltage battery is connected to the second terminal of the low-voltage DC connector, the third terminal of the low-voltage DC connector is connected to the third terminal of the flyback circuit, and the fourth terminal of the low-voltage DC connector is connected to the fourth terminal of the flyback circuit. The flyback circuit is used to pre-charge the first capacitor from the low-voltage battery. In this application embodiment, the flyback circuit has relatively high efficiency at low power, and its efficiency is higher than that of integrating a reverse pre-charge circuit in a DC-DC converter. Using the pre-charge system of this application embodiment can improve the reverse pre-charge efficiency. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.
[0031] Figure 1 This is a schematic diagram of the structure of a charging system provided in an embodiment of this application;
[0032] Figure 2 This is a schematic diagram of the structure of a pre-charging system provided in an embodiment of this application;
[0033] Figure 3 This is a schematic diagram of another pre-charge system provided in an embodiment of this application;
[0034] Figure 4 This is a schematic diagram of a flyback circuit provided in an embodiment of this application;
[0035] Figure 5 This is a schematic diagram of another flyback circuit provided in an embodiment of this application;
[0036] Figure 6 This is a schematic diagram of another flyback circuit provided in the embodiments of this application;
[0037] Figure 7 This is a schematic diagram of another flyback circuit provided in an embodiment of this application. Detailed Implementation
[0038] 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0039] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, system, product, or apparatus that comprises a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, products, or apparatuses.
[0040] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.
[0041] The DC-DC converter is a key component of the electrical system of new energy vehicles. The reverse pre-charge function of the DC-DC converter is generally achieved through a reverse pre-charge circuit. Currently, the reverse pre-charge circuit is usually integrated into the DC-DC converter, resulting in low reverse pre-charge efficiency. Please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic diagram of a charging system provided in an embodiment of this application. Figure 1 As shown, the charging system includes: a high-voltage battery, a high-voltage DC connector, a DC-DC converter, a low-voltage DC connector, a first capacitor C1, and a low-voltage battery. The DC-DC converter includes DC-DC power devices and a low-voltage side filter. The DC-DC converter may also include a high-voltage side filter, and the low-voltage side filter may include an electromagnetic compatibility (EMC) filter. The DC-DC power devices may include power devices (e.g., power switches, diodes, etc.) in the DC-DC converter. By multiplexing the power switches and diodes in the DC-DC power devices, the DC-DC power devices have a reverse pre-charge function.
[0042] When the charging system performs forward charging, the direction of forward charging is: high-voltage battery → high-voltage DC connector → DC-DC power device → low-voltage side filter → low-voltage DC connector → low-voltage battery. At this time, the DC-DC power device is equivalent to a buck circuit.
[0043] When the charging system implements the reverse pre-charging function, the reverse pre-charging direction is: low-voltage battery → low-voltage DC connector → low-voltage side filter → DC-DC power device → high-voltage DC connector → high-voltage battery. At this time, the DC-DC power device is equivalent to a boost circuit.
[0044] It should be noted that when this charging system implements the reverse pre-charge function, an additional RC filter circuit is required on the low-voltage side, which will occupy more space. Furthermore, when the reverse pre-charge power is low, the efficiency of the DC-DC power devices is also low.
[0045] This application provides a pre-charge system that can improve reverse pre-charge efficiency.
[0046] Please see Figure 2 , Figure 2 This is a schematic diagram of a pre-charging system provided in an embodiment of this application. Figure 2 As shown, the pre-charge system includes a high-voltage battery 10, a high-voltage DC connector 20, a flyback circuit 30, a low-voltage DC connector 40, a first capacitor C1, and a low-voltage battery 50. The positive terminal of the high-voltage battery 10 is connected to the first terminal of the high-voltage DC connector 20, the negative terminal of the high-voltage battery 10 is connected to the second terminal of the high-voltage DC connector 20, the third terminal of the high-voltage DC connector 20 is connected to the first terminal of the flyback circuit 30 and the positive terminal of the first capacitor, the fourth terminal of the high-voltage DC connector 20 is connected to the second terminal of the flyback circuit 30 and the negative terminal of the first capacitor, the positive terminal of the low-voltage battery 50 is connected to the first terminal of the low-voltage DC connector 40, the negative terminal of the low-voltage battery 50 is connected to the second terminal of the low-voltage DC connector 40, the third terminal of the low-voltage DC connector 40 is connected to the third terminal of the flyback circuit 30, and the fourth terminal of the low-voltage DC connector 40 is connected to the fourth terminal of the flyback circuit 30.
[0047] The flyback circuit 30 is used to precharge the first capacitor C1 from the low-voltage battery 50.
[0048] In this embodiment, the high-voltage battery 10 can be a power battery in a vehicle. The high-voltage battery 10 can be a lithium battery, and its voltage is generally above 100V. The high-voltage battery 10 can be used to power the motor in the vehicle.
[0049] The low-voltage battery 50 can be a battery in the vehicle that supplies power to low-voltage loads. The low-voltage battery 50 can be a rechargeable battery or a lithium battery, and its voltage is generally around 12V / 24V / 48V. The low-voltage load can be an electronic control unit (ECU) in the vehicle, which may include a vehicle infotainment system, music player, windshield wipers, steering module, braking module, etc., but this application does not limit the scope of the embodiment.
[0050] The high-voltage DC connector is the interface connecting the high-voltage battery and the flyback circuit, while the low-voltage DC connector is the interface connecting the low-voltage battery and the flyback circuit. These connectors ensure a good fit between the DC-DC converter and the vehicle, guaranteeing good waterproof and dustproof performance.
[0051] Flyback circuits are highly efficient at low power levels (e.g., below 400W), and their efficiency is higher than that of integrating a reverse precharge circuit in a DC-DC converter. The reverse precharge power of a flyback circuit is typically around 100W. Using the precharge system of this application embodiment can improve the reverse precharge efficiency.
[0052] In this embodiment, a separate flyback circuit is designed between the high-voltage DC connector and the low-voltage DC connector to achieve reverse pre-charge. This eliminates the need to reuse DC-DC power devices, reduces circuit loop paths, and increases space utilization by adding the flyback circuit in the middle space between the high-voltage and low-voltage DC connectors. Furthermore, the DC-DC power devices do not need to have reverse pre-charge functionality, thus reducing the size of the DC / DC converter and simplifying the design of the low-voltage side filter.
[0053] Compared with reusing DC-DC power devices to achieve the pre-charge function, the flyback circuit of this application embodiment can improve the power conversion efficiency of the reverse pre-charge function. The low-voltage side filter does not need to be added with additional design. For the case where the high-voltage DC connector and the low-voltage DC connector are laid out on the same side, the spatial layout adaptability can be enhanced.
[0054] The flyback circuit 30 can be used in a DC-DC converter; please refer to [link / reference]. Figure 3 , Figure 3 This is a schematic diagram of another pre-charge system provided in an embodiment of this application. For example... Figure 3 As shown, in Figure 2Based on this, the third end of the high-voltage DC connector 20 is connected to the first end of the DC-DC power device 60, the fourth end of the high-voltage DC connector 20 is connected to the second end of the DC-DC power device 60, the third end of the DC-DC power device 60 is connected to the first end of the low-voltage side filter 70, the fourth end of the DC-DC power device 60 is connected to the second end of the low-voltage side filter 70, the third end of the low-voltage side filter 70 is connected to the third end of the low-voltage DC connector 40, and the fourth end of the low-voltage side filter 70 is connected to the fourth end of the low-voltage DC connector 40.
[0055] In this embodiment, the flyback circuit 30 can be used in a DC-DC converter. The high-voltage battery 10 and the low-voltage battery 50 are located on one side of the vehicle, and the DC-DC converter can be located on the other side of the vehicle. The other side where the DC-DC converter is located can have an extra space for placing the flyback circuit 30, thereby making full use of the space on the same side and increasing the space utilization rate.
[0056] Please see Figure 4 , Figure 4 This is a schematic diagram of a flyback circuit provided in an embodiment of this application. Figure 4 As shown, the flyback circuit 30 includes: a first transformer module T1, a first switching transistor Q1, and a first diode D1; the first end of the primary winding of the first transformer module T1 is connected to the third end of the low-voltage DC connector 40, the second end of the primary winding of the first transformer module T1 is connected to the first end of the first switching transistor Q1, the second end of the first switching transistor Q1 is connected to the fourth end of the low-voltage DC connector 40, the first end of the secondary winding of the first transformer module T1 is connected to the positive terminal of the first diode D1, the negative terminal of the first diode D1 is connected to the third end of the high-voltage DC connector 20, and the second end of the secondary winding of the first transformer module T1 is connected to the fourth end of the high-voltage DC connector 20.
[0057] In this embodiment, the flyback circuit 30 has a simple structure. When the first switch Q1 is in the on state, the flyback circuit 30 realizes the pre-charge function and can control the low-voltage battery 50 to pre-charge the first capacitor C1.
[0058] The first transformer module T1 may include a first transformer or a first instrument transformer. The first instrument transformer may include a voltage transformer or a current transformer.
[0059] Please see Figure 5 , Figure 5 This is a schematic diagram of another flyback circuit provided in an embodiment of this application. For example... Figure 5As shown, the flyback circuit 30 includes: a second transformer module T2, a second switch Q2, a third switch Q3, a second diode D2, a third diode D3, a fourth diode D4, a first inductor L1, and a second inductor L2; the first terminal of the second switch Q2 is connected to the cathode of the second diode D2 and the third terminal of the low-voltage DC connector 40, the second terminal of the second switch Q2 is connected to the first terminal of the first inductor L1 and the cathode of the third diode D3, and the second terminal of the first inductor L1 is connected to the first terminal of the second inductor L2 and the first terminal of the primary winding of the second transformer module T2. The positive terminal of the second diode D2 is connected to the first terminal of the third switch Q3, the second terminal of the second inductor L2, and the second terminal of the primary winding of the second transformer module T2. The second terminal of the third switch Q3 is connected to the positive terminal of the third diode D3 and the fourth terminal of the low-voltage DC connector 40. The first terminal of the secondary winding of the second transformer module T2 is connected to the positive terminal of the fourth diode D4. The negative terminal of the fourth diode D4 is connected to the third terminal of the high-voltage DC connector 20. The second terminal of the secondary coil of the second transformer module T2 is connected to the fourth terminal of the high-voltage DC connector 20.
[0060] In this embodiment, the flyback circuit 30 is a dual-switch flyback circuit 30, which controls the conduction or cutoff of two switching transistors (second switching transistor Q2 and third switching transistor Q3) to achieve pre-charging of the low-voltage battery 50 to the first capacitor C1.
[0061] The second transformer module T2 may include a second transformer or a second instrument transformer. The second instrument transformer may include a voltage transformer or a current transformer.
[0062] Please see Figure 6 , Figure 6 This is a schematic diagram of another flyback circuit provided in an embodiment of this application. For example... Figure 6As shown, the flyback circuit 30 includes: a third transformer module T3, a fourth switch Q4, a fifth diode D5, a sixth diode D6, a second capacitor C2, and a first resistor R1; the first end of the first resistor R1 is connected to the first end of the second capacitor C2, the first end of the primary winding of the third transformer module T3, and the third end of the low-voltage DC connector 40; the second end of the first resistor R1 is connected to the second end of the second capacitor C2 and the negative terminal of the fifth diode D5; the positive terminal of the fifth diode D5 is connected to the second end of the primary winding of the third transformer module T3 and the first end of the fourth switch Q4; the second end of the fourth switch Q4 is connected to the fourth end of the low-voltage DC connector 40; the first end of the secondary winding of the third transformer module T3 is connected to the positive terminal of the sixth diode D6; the negative terminal of the sixth diode D6 is connected to the third end of the high-voltage DC connector 20; and the second end of the secondary winding of the third transformer module T3 is connected to the fourth end of the high-voltage DC connector 20. In this circuit, the positive terminal of the body diode Ds of the fourth switch Q4 is connected to the second terminal of the fourth switch Q4, and the negative terminal of the body diode Ds is connected to the first terminal of the fourth switch Q4.
[0063] In this embodiment, the flyback circuit 30 is an RCD clamp flyback circuit. The first resistor R1, the second capacitor C2, and the fifth diode D5 in the RCD clamp flyback circuit serve as RCD clamps. The RCD clamp flyback circuit can suppress voltage spikes and prevent excessively high voltages between the first and second terminals of the fourth switch Q4 in the circuit, thereby preventing the fourth switch Q4 from being damaged due to excessive voltage.
[0064] The third transformer module T3 may include a third transformer or a third instrument transformer. The third instrument transformer may include a voltage transformer or a current transformer.
[0065] Please see Figure 7 , Figure 7 This is a schematic diagram of another flyback circuit provided in an embodiment of this application. For example... Figure 7As shown, the flyback circuit 30 includes: a fourth transformer module T4, a fifth switch Q5, a sixth switch Q6, a seventh diode D7, a third capacitor C3, and a third inductor L3; the first end of the third capacitor C3 is connected to the first end of the third inductor L3, the first end of the primary winding of the fourth transformer module T4, and the third end of the low-voltage DC connector 40; the second end of the third capacitor C3 is connected to the first end of the fifth switch Q5; the second end of the fifth switch Q5 is connected to the second end of the third inductor L3, the first end of the sixth switch Q6, and the second end of the primary winding of the fourth transformer module T4; the second end of the sixth switch Q6 is connected to the fourth end of the low-voltage DC connector 40; the first end of the secondary winding of the fourth transformer module T4 is connected to the positive terminal of the seventh diode D7; the negative terminal of the seventh diode D7 is connected to the third end of the high-voltage DC connector 20; and the second end of the secondary winding of the fourth transformer module T4 is connected to the fourth end of the high-voltage DC connector 20.
[0066] In this embodiment, the flyback circuit 30 is an active clamp flyback circuit. When the sixth switch Q6 is turned on, the input energy is stored in the primary winding of the fourth transformer module T4. After the sixth switch Q6 is turned off, the energy of the primary winding of the fourth transformer module T4 is fed back to the third terminal of the low-voltage DC connector 40 through the fifth switch Q5 and the third capacitor C3, thereby suppressing voltage spikes and realizing soft switching.
[0067] The fourth transformer module T4 may include a fourth transformer or a fourth instrument transformer. The fourth instrument transformer may include a voltage transformer or a current transformer.
[0068] This application embodiment also provides a vehicle, which may include... Figure 1 The pre-charge system.
[0069] The specific structure of the pre-charge system can be found above. Figure 2 or Figure 3 The circuit shown.
[0070] 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.
[0071] In the several embodiments provided in this application, it should be understood that the disclosed pre-charging system can be implemented in other ways. For example, the embodiments of the pre-charging system described above are merely illustrative. For instance, the division of the 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.
Claims
1. A pre-charge system, characterized in that, The device includes a high-voltage battery, a high-voltage DC connector, a flyback circuit, a low-voltage DC connector, a first capacitor, and a low-voltage battery. The positive terminal of the high-voltage battery is connected to the first terminal of the high-voltage DC connector, the negative terminal of the high-voltage battery is connected to the second terminal of the high-voltage DC connector, the third terminal of the high-voltage DC connector is connected to the first terminal of the flyback circuit and the positive terminal of the first capacitor, the fourth terminal of the high-voltage DC connector is connected to the second terminal of the flyback circuit and the negative terminal of the first capacitor, the positive terminal of the low-voltage battery is connected to the first terminal of the low-voltage DC connector, the negative terminal of the low-voltage battery is connected to the second terminal of the low-voltage DC connector, the third terminal of the low-voltage DC connector is connected to the third terminal of the flyback circuit, and the fourth terminal of the low-voltage DC connector is connected to the fourth terminal of the flyback circuit. The flyback circuit is used to precharge the first capacitor from the low-voltage battery.
2. The pre-charge system according to claim 1, characterized in that, The flyback circuit includes: a first transformer module, a first switching transistor, and a first diode; the first end of the primary winding of the first transformer module is connected to the third end of the low-voltage DC connector, the second end of the primary winding of the first transformer module is connected to the first end of the first switching transistor, the second end of the first switching transistor is connected to the fourth end of the low-voltage DC connector, the first end of the secondary winding of the first transformer module is connected to the anode of the first diode, the cathode of the first diode is connected to the third end of the high-voltage DC connector, and the second end of the secondary winding of the first transformer module is connected to the fourth end of the high-voltage DC connector.
3. The pre-charge system according to claim 2, characterized in that, The first transformer module includes a first transformer or a first current transformer.
4. The pre-charge system according to claim 1, characterized in that, The flyback circuit includes: a second transformer module, a second switching transistor, a third switching transistor, a second diode, a third diode, a fourth diode, a first inductor, and a second inductor; the first terminal of the second switching transistor is connected to the negative terminal of the second diode and the third terminal of the low-voltage DC connector; the second terminal of the second switching transistor is connected to the first terminal of the first inductor and the negative terminal of the third diode; the second terminal of the first inductor is connected to the first terminal of the second inductor and the first terminal of the primary winding of the second transformer module; the positive terminal of the second diode is connected to the first terminal of the third switching transistor, the second terminal of the second inductor, and the second terminal of the primary winding of the second transformer module; the second terminal of the third switching transistor is connected to the positive terminal of the third diode and the fourth terminal of the low-voltage DC connector; the first terminal of the secondary winding of the second transformer module is connected to the positive terminal of the fourth diode; the negative terminal of the fourth diode is connected to the third terminal of the high-voltage DC connector; and the second terminal of the secondary coil of the second transformer module is connected to the fourth terminal of the high-voltage DC connector.
5. The pre-charge system according to claim 4, characterized in that, The second transformer module includes a second transformer or a second current transformer.
6. The pre-charge system according to claim 1, characterized in that, The flyback circuit includes: a third transformer module, a fourth switching transistor, a fifth diode, a sixth diode, a second capacitor, and a first resistor; the first end of the first resistor is connected to the first end of the second capacitor, the first end of the primary winding of the third transformer module, and the third end of the low-voltage DC connector; the second end of the first resistor is connected to the second end of the second capacitor and the negative terminal of the fifth diode; the positive terminal of the fifth diode is connected to the second end of the primary winding of the third transformer module and the first end of the fourth switching transistor; the second end of the fourth switching transistor is connected to the fourth end of the low-voltage DC connector; the first end of the secondary winding of the third transformer module is connected to the positive terminal of the sixth diode; the negative terminal of the sixth diode is connected to the third end of the high-voltage DC connector; and the second end of the secondary winding of the third transformer module is connected to the fourth end of the high-voltage DC connector.
7. The pre-charge system according to claim 1, characterized in that, The flyback circuit includes: a fourth transformer module, a fifth switch, a sixth switch, a seventh diode, a third capacitor, and a third inductor; the first terminal of the third capacitor is connected to the first terminal of the third inductor, the first terminal of the primary winding of the fourth transformer module, and the third terminal of the low-voltage DC connector; the second terminal of the third capacitor is connected to the first terminal of the fifth switch; the second terminal of the fifth switch is connected to the second terminal of the third inductor, the first terminal of the sixth switch, and the second terminal of the primary winding of the fourth transformer module; the second terminal of the sixth switch is connected to the fourth terminal of the low-voltage DC connector; the first terminal of the secondary winding of the fourth transformer module is connected to the anode of the seventh diode; the cathode of the seventh diode is connected to the third terminal of the high-voltage DC connector; and the second terminal of the secondary coil of the fourth transformer module is connected to the fourth terminal of the high-voltage DC connector.
8. The pre-charge system according to any one of claims 1 to 7, characterized in that, The high-voltage battery and the low-voltage battery are located on the same side of the vehicle.
9. The pre-charge system according to any one of claims 1 to 7, characterized in that, The power of the flyback circuit is less than a set threshold.
10. A vehicle, characterized in that, Includes the pre-charge system as described in any one of claims 1 to 9.