Vehicle-mounted power supply device supporting reverse charging slow start and electric vehicle

Abstract

The utility model provides a vehicle-mounted power supply device supporting reverse charging slow start and an electric vehicle. The vehicle-mounted power supply device comprises a filter capacitor, a direct current conversion circuit, a reverse charging prevention circuit and a slow start circuit. Wherein one end of the filter capacitor is used for being connected with one output end of the direct-current conversion circuit and is used for being connected with one end of the low-voltage battery through the anti-backflow circuit, and the other end of the filter capacitor is used for being connected with the other output end of the direct-current conversion circuit and the other end of the low-voltage battery. The slow start circuit comprises a power supply, and the power supply firstly charges the filter capacitor before the direct current conversion circuit receives power supplied by the low-voltage battery through the filter capacitor, so that the impact current when the anti-backflow circuit is conducted is reduced, and the anti-backflow circuit is protected. And the slow start circuit is simple in structure and high in reliability.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicles, and more specifically, to an on-board power supply device and an electric vehicle that support reverse charging and slow start. Background Art

[0002] When an electric vehicle is powered up at high voltage, the low-voltage battery in the vehicle is used to reversely precharge the large capacitors on the high-voltage port. This prevents the pulse current generated at the moment of power-up from damaging the capacitors and power devices. The DC conversion circuits in on-board power supplies are increasingly being used for reverse precharging. To prevent backfeed failures caused by DC conversion circuit failure, currently common DC conversion circuits require the addition of anti-backfeed switches. However, the internal capacitance on the low-voltage side of the DC conversion circuit is large, and the surge current generated by forcibly opening the anti-backfeed switch can easily break down the anti-backfeed switch, reducing the reliability of the on-board power supply. Utility Model Content

[0003] This application provides an on-board power supply device and electric vehicle that supports reverse charging and slow start. The power supply in the slow start circuit precharges the filter capacitor on the low-voltage side of the DC converter circuit, reducing the inrush current when the anti-backfeed circuit is turned on, thereby protecting the anti-backfeed circuit. Furthermore, the slow start circuit has a simple structure and high reliability.

[0004] In a first aspect, a vehicle-mounted power supply device supporting reverse charging and slow start is provided, the vehicle-mounted power supply device comprising a filter capacitor, a DC conversion circuit, an anti-backflow circuit, and a slow start circuit. One end of the filter capacitor is used to connect to an output end of the DC conversion circuit and to connect to one end of the low-voltage battery through the anti-backflow circuit, and the other end of the filter capacitor is used to connect to the other output end of the DC conversion circuit and the other end of the low-voltage battery. The slow start circuit comprises a power supply that first charges the filter capacitor before the DC conversion circuit receives power from the low-voltage battery through the filter capacitor.

[0005] According to the present application, before the DC converter circuit receives power from the low-voltage battery through the filter capacitor, the power supply in the soft-start circuit precharges the filter capacitor. This reduces the inrush current when the anti-backfeed circuit is turned on, protecting the anti-backfeed circuit. Furthermore, the soft-start circuit has a simple structure and high reliability.

[0006] In combination with the first aspect, in certain implementations of the first aspect, the soft-start circuit further includes a diode and / or a current-limiting resistor, and the power supply is used to connect one end of the filter capacitor through the diode and / or the current-limiting resistor.

[0007] According to the solution of the present application, the current limiting resistor can prevent the power supply and the diode from being burned out by excessive current, and the diode can prevent the current of the DC conversion circuit from flowing to the power supply when working in the forward direction, thereby further improving the reliability of the vehicle-mounted power supply device.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the on-board power supply device further includes a primary capacitor, one end of the primary capacitor being connected to an input end of the DC conversion circuit, and the other end of the primary capacitor being connected to another input end of the DC conversion circuit. During the process of the one power source charging the filter capacitor, in response to the voltage of the filter capacitor being greater than or equal to a first voltage threshold, the anti-backfeed circuit is turned on, so that the DC conversion circuit converts the low-voltage DC power provided by the low-voltage battery into high-voltage DC power to charge the primary capacitor.

[0009] It can be understood that when the voltage at one end of the filter capacitor is greater than or equal to the first voltage threshold, the current of the circuit when the anti-backfeed circuit is turned on is insufficient to damage the anti-backfeed circuit.

[0010] It can be understood that the above reverse charging can be understood as the low-voltage battery pre-charging the primary capacitor through the above DC conversion circuit.

[0011] According to the solution of the present application, the anti-backfeed circuit is turned on after the voltage of the filter capacitor is charged to the first voltage threshold, which can increase the speed of charging the primary capacitor while avoiding the risk of breakdown and damage of the anti-backfeed circuit. The vehicle-mounted power supply device has high reliability and strong practicality.

[0012] In combination with the first aspect, in certain implementations of the first aspect, during the process in which the DC conversion circuit is used to convert high-voltage DC power into low-voltage DC power to charge the low-voltage battery, the power supply stops charging the filter capacitor.

[0013] According to the present application, during the forward operation of the DC converter circuit, the power supply in the soft-start circuit can stop charging the filter capacitor, reducing the power supply's energy consumption and extending its service life. Furthermore, the on-board power supply device can both achieve energy conversion during the reverse operation of the DC converter circuit and isolate internal faults on the low-voltage side during forward operation of the DC converter circuit, resulting in high reliability.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the anti-backfeed circuit includes an anti-backfeed switch tube and an anti-backfeed control circuit, the anti-backfeed control circuit includes a first control subcircuit and a second control subcircuit, the first control subcircuit is used to control the conduction and shutdown of the anti-backfeed switch tube through the second control subcircuit by receiving a control signal.

[0015] According to the solution of the present application, the first control subcircuit in the anti-backfeed control circuit can control the conduction and shutdown of the anti-backfeed switch tube by controlling the second control subcircuit in response to the control signal, with high control accuracy, further improving the reliability of the vehicle-mounted power supply device.

[0016] In conjunction with the first aspect, in certain implementations of the first aspect, the second control subcircuit includes a first switching tube and a totem pole unit. During the process of the one power supply charging the filter capacitor, in response to the voltage of the filter capacitor being less than the first voltage threshold, the first switching tube is turned on, so that the totem pole unit drives the anti-backfeed switching tube to turn off. In response to the voltage of the filter capacitor being greater than or equal to the first voltage threshold, the first switching tube is turned off, so that the totem pole unit drives the anti-backfeed switching tube to turn on. When the first switching tube is turned off, the voltage difference between the control electrode and the first electrode of the first switching tube is less than or equal to the second voltage threshold.

[0017] According to the solution of the present application, the vehicle-mounted power supply device provided in the present application can reduce the risk of the switch tube being broken down when the DC conversion circuit works in reverse by limiting the voltage difference between the control electrode and the first electrode when the first switch tube in the anti-backfeed control circuit is disconnected, and has high reliability.

[0018] In conjunction with the first aspect, in certain implementations of the first aspect, the control electrode of the first switching transistor is connected to the first control subcircuit, the first electrode of the first switching transistor is connected to one end of the filter capacitor, and one end of the first control subcircuit is connected to one end of the filter capacitor. In response to the voltage of the filter capacitor being greater than or equal to the first voltage threshold, the first control subcircuit is turned on, so that the one end of the filter capacitor is connected to the control electrode of the first switching transistor.

[0019] According to the solution of the present application, in the anti-backfeed control circuit, the control electrode and the first electrode of the first switching tube are connected to a node with the same potential when the first switching tube is disconnected, thereby reducing the potential difference between the control electrode and the first electrode of the first switching tube. This implementation method does not require the addition of additional circuits, and the circuit structure is simple and the reliability is high.

[0020] In conjunction with the first aspect, in certain implementations of the first aspect, the first control subcircuit includes a first switch unit, a second switch unit, a first resistor, and a second resistor. The first end of the first switch unit is configured to receive the control signal via the first resistor, the second end of the first switch unit is configured to connect to the positive electrode of the first battery via the second resistor, the third end of the first switch unit is configured to connect to the first end of the second switch unit, and the fourth end of the first switch unit is connected to ground. The second end of the second switch unit is configured to connect to the control electrode of the first switch transistor, and the third end of the second switch unit is configured to connect to one end of the filter capacitor.

[0021] According to the solution of the present application, the first control subcircuit may include a first switch unit and a second switch unit, and the second switch unit may connect one end of the filter capacitor and the control electrode of the first switch tube, thereby reducing the voltage difference between the control electrode and the first electrode of the first switch tube when the first switch tube is disconnected to protect the first switch tube, and the reliability of the vehicle power supply device is high.

[0022] In conjunction with the first aspect, in certain implementations of the first aspect, the first switch unit includes a second switch transistor, a third switch transistor, a third resistor, and a fourth resistor, and the second switch unit includes a fourth switch transistor and a fifth resistor. The control electrode of the second switch transistor is connected to the first end of the first switch unit, the first electrode of the second switch transistor is used to connect to the control end of the third switch transistor, and the second electrode of the second switch transistor is connected to the fourth end of the first switch unit, wherein the second electrode of the second switch transistor is short-circuited to the control electrode of the second switch transistor through the third resistor. The first electrode of the third switch transistor is connected to the second end of the first switch unit, and the second electrode of the third switch transistor is connected to the third end of the first switch unit, wherein the control electrode of the third switch transistor is short-circuited to the first electrode of the third switch transistor through the fourth resistor. The control electrode of the fourth switch transistor is connected to the first end of the second switch unit, the first electrode of the fourth switch transistor is connected to the second end of the second switch unit, and the second electrode of the fourth switch transistor is connected to the third end of the second switch unit, wherein the control electrode of the fourth switch transistor is short-circuited to the second electrode of the fourth switch transistor through the fifth resistor.

[0023] According to the present application, a specific implementation of a first control subcircuit is provided. Upon receiving a control signal, the first control subcircuit can adjust the potential of the control electrode of the first switch tube via the second and third switch tubes in the first switch unit and the fourth switch tube in the second switch unit, thereby controlling the anti-backfeed switch tube. This implementation provides high reliability for the first control subcircuit. Furthermore, the third and fifth resistors can prevent malfunction of the second and fourth switch tubes.

[0024] In combination with the first aspect, in certain implementations of the first aspect, the second control subcircuit also includes another diode, the cathode of the other diode is used to connect to the control electrode of the first switching tube, and the anode of the other diode is used to connect to the first electrode of the first switching tube.

[0025] According to the solution of the present application, when the first switch tube is turned off, the other diode can clamp the control electrode voltage of the first switch tube and the voltage of the first electrode of the first switch tube. At this time, the voltage difference between the control electrode and the first electrode of the first switch tube approaches the voltage drop of the diode, with a simple structure and strong reliability.

[0026] In combination with the first aspect, in certain implementations of the first aspect, the first control subcircuit includes a third switch unit, a sixth resistor and a seventh resistor, the first end of the third switch unit is used to receive the control signal through the sixth resistor, the second end of the third switch unit is used to connect to the control electrode of the first switch tube through the seventh resistor, and the third end of the third switch unit is grounded.

[0027] According to the solution of the present application, another specific implementation of the first control subcircuit is provided, and the circuit structure of the first control subcircuit is simple and the reliability is high.

[0028] In a second aspect, an electric vehicle is provided, comprising a low-voltage battery and an on-board power supply device, wherein the on-board power supply device comprises a filter capacitor, a DC conversion circuit, an anti-backflow circuit, and a slow-start circuit. One end of the filter capacitor is used to connect to an output end of the DC conversion circuit and to connect to one end of the low-voltage battery via the anti-backflow circuit, and the other end of the filter capacitor is used to connect to another output end of the DC conversion circuit and to the other end of the low-voltage battery. The slow-start circuit comprises a power supply that first charges the filter capacitor before the DC conversion circuit receives power from the low-voltage battery via the filter capacitor.

[0029] According to the present application, before the DC converter circuit receives power from the low-voltage battery through the filter capacitor, the power supply in the soft-start circuit precharges the filter capacitor. This reduces the inrush current when the anti-backfeed circuit is turned on, protecting the anti-backfeed circuit. Furthermore, the soft-start circuit has a simple structure and high reliability.

[0030] In conjunction with the second aspect, in certain implementations of the second aspect, the on-board power supply device further includes a primary capacitor, one end of the primary capacitor being connected to an input end of the DC conversion circuit, and the other end of the primary capacitor being connected to another input end of the DC conversion circuit. During the process of the one power supply charging the filter capacitor, in response to the voltage of the filter capacitor being greater than or equal to a first voltage threshold, the anti-backfeed circuit is turned on, so that the DC conversion circuit converts the low-voltage DC power provided by the low-voltage battery into high-voltage DC power to charge the primary capacitor.

[0031] According to the solution of the present application, the anti-backfeed circuit is turned on after the voltage of the filter capacitor is charged to the first voltage threshold, which can increase the speed of charging the primary capacitor while avoiding the risk of breakdown and damage of the anti-backfeed circuit. The vehicle-mounted power supply device has high reliability and strong practicality.

[0032] In combination with the second aspect, in certain implementations of the second aspect, the electric vehicle also includes a high-voltage battery, and during the process in which the DC conversion circuit is used to convert the high-voltage direct current provided by the high-voltage battery into low-voltage direct current to charge the low-voltage battery, the power supply stops charging the filter capacitor.

[0033] According to the present application, during the forward operation of the DC converter circuit, the power supply in the soft-start circuit can stop charging the filter capacitor, reducing the power supply's energy consumption and extending its service life. Furthermore, the on-board power supply device can both achieve energy conversion during the reverse operation of the DC converter circuit and isolate internal faults on the low-voltage side during forward operation of the DC converter circuit, resulting in high reliability.

[0034] In conjunction with the second aspect, in certain implementations of the second aspect, the on-board power supply device further includes an anti-backfeed control circuit, the anti-backfeed control circuit including a first control subcircuit and a second control subcircuit, the first control subcircuit being configured to control the on and off of the anti-backfeed circuit via the second control subcircuit by receiving a control signal. The second control subcircuit includes a first switching tube and a totem pole unit. During the process of the power supply charging the filter capacitor, in response to the voltage of the filter capacitor being less than the first voltage threshold, the first switching tube is turned on, causing the totem pole unit to drive the anti-backfeed circuit to turn off. In response to the voltage of the filter capacitor being greater than or equal to the first voltage threshold, the first switching tube is turned off, causing the totem pole unit to drive the anti-backfeed circuit to turn on. When the first switching tube is turned off, the voltage difference between the control electrode and the first electrode of the first switching tube is less than or equal to the second voltage threshold.

[0035] According to the present invention, the first control subcircuit in the anti-backfeed control circuit can control the on and off of the anti-backfeed switch by controlling the second control subcircuit in response to a control signal, resulting in high control accuracy and further improving the reliability of the vehicle-mounted power supply device. Furthermore, the vehicle-mounted power supply device provided by the present invention can reduce the risk of breakdown of the first switch in the anti-backfeed control circuit during reverse operation of the DC converter circuit by limiting the voltage difference between the control electrode and the first electrode when the first switch is disconnected, thereby improving reliability.

[0036] As for the technical effects of the solution provided in the second aspect above, please refer to the corresponding description of the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of an electric vehicle 10 provided in an embodiment of the present application;

[0038] Figure 2 This is a schematic diagram of the system architecture and application scenarios applicable to the vehicle-mounted power supply device 13 provided in an embodiment of the present application;

[0039] Figure 3 1 is a structural diagram of a slow-start circuit 133 provided in an embodiment of the present application;

[0040] Figure 41 is a schematic structural diagram of an anti-backfeed circuit 132 provided in an embodiment of the present application;

[0041] Figure 5 13 is a schematic structural diagram of the second control circuit 1322b provided in an embodiment of the present application;

[0042] Figure 6 13 is a circuit diagram of an anti-backfeed control circuit 1322 provided in an embodiment of the present application;

[0043] Figure 7 13 is a circuit diagram of another anti-backfeed control circuit 1322 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The technical solution in this application will be described below with reference to the accompanying drawings.

[0045] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification of the present application and the appended claims, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context. It should also be understood that in the embodiments of the present application, "one or more" refers to one, two or more; "and / or" describes the association relationship of associated objects, indicating that three relationships may exist; for example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0046] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0047] In the embodiments of the present application, "connection" can be understood as electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components, such as A and B, or A and C can be directly connected, C can be directly connected to B, and A and B can be connected through C. In some scenarios, "connection" can also be understood as coupling, such as electromagnetic coupling between two inductors. In short, the connection between A and B enables the transmission of electrical energy between A and B.

[0048] It should be noted that the switching tubes and switches in the embodiments of the present application can be one or more of various types of switching tubes such as relays, metal oxide semiconductor field effect transistors (MOSFETs), bipolar junction transistors (BJTs), and insulated gate bipolar transistors (IGBTs), which are not listed one by one in the embodiments of the present application. Each switching tube includes a first electrode, a second electrode, and a control electrode, wherein the control electrode is used to control the conduction or disconnection of the switching tube. When the switching tube is turned on, current can be transmitted between the first electrode and the second electrode of the switching tube. When the switching tube is turned off, current cannot be transmitted between the first electrode and the second electrode of the switching tube.

[0049] With the popularity of new energy electric vehicles, high-voltage platforms have become a development trend. That is, new energy vehicles are equipped with high-voltage batteries and corresponding high-voltage electrical equipment, and high-voltage electrical equipment generally has large capacitance at the high-voltage port. When the electric vehicle is powered on at high voltage, the low-voltage battery in the electric vehicle needs to reversely pre-charge the large capacitor at the high-voltage port to prevent the pulse current generated at the moment of power-on from damaging the capacitor and power devices. On-board direct current (DC / DC) converters are one of the key devices in fuel cell vehicles, pure electric vehicles, and hybrid vehicles. They mainly provide stable low-voltage power to various controllers and low-voltage devices, including electronic control units (ECUs), power steering, brake control, low-voltage cooling fans, low-voltage water pumps, etc. Currently, there are more and more proposals to achieve reverse pre-charging through DC / DC circuits, eliminating the need for pre-charging high-voltage contactors and high-power current-limiting resistors, which can save costs and space in the vehicle and improve system reliability.

[0050] To prevent internal DC / DC failures from causing the low-voltage battery voltage to drop, potentially leading to power outages in other low-voltage equipment and uncontrollable consequences, an ORing circuit is required on the low-voltage side of the DC / DC circuit to prevent backflow failures caused by DC / DC circuit failures. However, since the ORing circuit automatically turns on when the internal voltage of the DC / DC circuit exceeds the low-voltage battery voltage, other control measures are required to ensure that the ORing circuit turns on when the DC / DC circuit is operating in reverse. However, due to the large filter capacitors on the low-voltage side of the DC / DC circuit (typically several thousand microfarads), forcing the ORing circuit to turn on generates a large inrush current, which can easily cause the ORing circuit to fail and cause a short-term over-discharge of the low-voltage battery, leading to an undervoltage fault.

[0051] In view of this, the present application provides an on-board power supply device and electric vehicle with reverse charging and slow start. The power supply in the slow start circuit pre-charges the filter capacitor on the low-voltage side of the DC converter circuit, thereby reducing the inrush current when the anti-backfeed circuit is turned on and protecting the anti-backfeed circuit. Furthermore, the slow start circuit has a simple structure and high reliability.

[0052] Figure 1 A schematic diagram of an electric vehicle 10 provided in an embodiment of the present application.

[0053] See Figure 1 The electric car 10 includes a high-voltage battery 11, a low-voltage battery 12 and an on-board power supply device 13. The on-board power supply device 13 is used to be connected between the high-voltage battery 11 and the low-voltage battery 12, and the high-voltage port of the on-board power supply device 13 has a primary capacitor. The on-board power supply device 13 provided in the embodiment of the present application can be used to receive power from the high-voltage battery 11 and charge the low-voltage battery 12. The on-board power supply device 13 can also be used to receive power from the low-voltage battery 12 and charge the primary capacitor. The on-board power supply device 13 provided in the present application does not add additional circuit devices to assist in charging the primary capacitor, which can avoid increasing the design complexity and reduce the cost and volume of the on-board power supply device 13.

[0054] It should be understood that the high-voltage battery 11 may be a power battery of the electric vehicle 10 , and the low-voltage battery 12 may be an on-board low-voltage storage battery, which is not limited in the embodiment of the present application.

[0055] Figure 2 It is a schematic diagram of the system architecture and application scenarios applicable to the vehicle-mounted power supply device 13 provided in the embodiment of the present application.

[0056] like Figure 2As shown, the on-board power supply device 13 may include a DC conversion circuit (hereinafter referred to as a DC / DC circuit) 130, a filter capacitor 131, an anti-backfeed circuit 132 and a soft-start circuit 133. Among them, one output terminal out1 of the DC / DC circuit 130 is used to connect to one end of the filter capacitor 131, and the other output terminal out2 of the DC / DC circuit 130 is used to connect to the other end of the filter capacitor 131. At the same time, one end of the filter capacitor 131 is also used to connect to one end of the low-voltage battery 12 through the anti-backfeed circuit 132, and one end of the filter capacitor is also used to connect to one end of the soft-start circuit 133, and the other end of the filter capacitor 131 is also used to connect to the other end of the low-voltage battery 12.

[0057] In some embodiments, the vehicle power supply device 13 may further include a primary capacitor 134 , one end of which is used to connect to an input end in1 of the DC / DC circuit 130 , and the other end of which is used to connect to another input end in2 of the DC / DC circuit 130 .

[0058] In some embodiments, the vehicle power supply device 13 may further include a power factor correction (PFC) circuit 135. The PFC circuit 135 may be connected in parallel between the input end of the vehicle power supply device 13 and the primary capacitor 134. The PFC circuit 135 may receive alternating current from an external power source (e.g., a high-voltage battery 11) and output a first direct current, so that the DC / DC circuit 130 may receive the first direct current through the primary capacitor 134 and output a second direct current. It is easy to understand that the voltage of the second direct current is lower than the voltage of the first direct current.

[0059] It can be understood that in the embodiment of the present application, the working state of the DC / DC circuit 130 includes reverse operation and forward operation.

[0060] During the reverse operation of the DC / DC circuit 130, after the soft-start circuit 133 pre-charges the filter capacitor 131, the DC / DC circuit 130 is used to receive power from the low-voltage battery 12 through the filter capacitor 131 and the anti-backfeed circuit 132, and charge the primary capacitor 134.

[0061] When the DC / DC circuit 130 is working in the forward direction, the DC / DC circuit is used to receive power from the high-voltage battery 11 and charge the low-voltage battery 12 through the anti-backflow circuit 132 .

[0062] The following describes the operation process of the slow-start circuit 133 in different working states of the DC / DC circuit.

[0063] Figure 31 is a structural diagram of a slow-start circuit 133 provided in an embodiment of the present application. Figure 3 As shown, the soft-start circuit 133 includes a power supply 1331, one end of which is connected to one end of the filter capacitor 131, and the other end of which is grounded. During reverse operation of the DC / DC circuit, before the DC / DC circuit 130 receives power from the low-voltage battery 12 through the filter capacitor 131, the power supply 1331 is used to charge the filter capacitor 131.

[0064] According to an embodiment of the present application, a power supply in the soft-start circuit is used to pre-charge the filter capacitor on the low-voltage side of the DC / DC circuit, thereby reducing the impact current when the anti-backfeed circuit is turned on. The structure of the soft-start circuit is simple and does not require an additional control circuit for control, and has high reliability.

[0065] In some embodiments, while the DC / DC circuit 130 receives power from the low-voltage battery 12 via the filter capacitor 131, the power supply 1331 can continuously charge the filter capacitor 131. According to the embodiment of the present application, the power supply 1331 is simple to control and highly reliable.

[0066] In some embodiments, while the DC / DC circuit 130 receives power from the low-voltage battery 12 via the filter capacitor 131, the power supply 1331 may stop charging the filter capacitor 131. According to embodiments of the present application, the lifespan of the filter capacitor 131 can be prevented from being shortened due to the filter capacitor 131 being in a charged state for a long time.

[0067] In some embodiments, the slow-start circuit 130 further includes a diode and / or a current-limiting resistor, and the power supply 1331 can be connected to one end of the filter capacitor 131 through the diode and / or the current-limiting resistor. Figure 3 As shown, the slow-start circuit 130 includes a diode D1 and a current-limiting resistor R1. The power supply 1331 can be connected to one end of the filter capacitor 131 through the diode D1 and the resistor R1 in sequence, wherein the anode of the diode D1 is connected to one end of the power supply 1331, and the cathode of the diode D1 is connected to one end of the resistor R1. According to the embodiment of the present application, the resistor R1 can prevent excessive current from burning out the power supply 1331 and the diode D1. The diode D1 can prevent the current from flowing to the power supply 1331 when the DC / DC circuit 130 is operating in the forward direction, further improving the reliability of the slow-start circuit 130.

[0068] In some embodiments, during the forward operation of the DC / DC circuit, the power supply 1331 stops charging the filter capacitor 131 . At this time, the power supply 1331 can be completely shut down, thereby reducing the energy consumption of the power supply 1331 and extending its service life.

[0069] Figure 41 is a structural diagram of an anti-backfeed circuit 132 provided in an embodiment of the present application.

[0070] like Figure 4 As shown, the anti-backfeed circuit 132 includes an ORING switch tube 1321 and an anti-backfeed control circuit 1322 . The anti-backfeed control circuit 1322 is used to control the on and off of the ORING switch tube 1321 .

[0071] In some embodiments, during the reverse operation of the DC / DC circuit 130 , in response to the voltage of the filter capacitor 131 being less than the first voltage threshold, the anti-backfeed switch 1321 is turned off, and the slow-start circuit 133 continues to charge the filter capacitor 131 .

[0072] In some embodiments, during the reverse operation of the DC / DC circuit 130, in response to the voltage of the filter capacitor 131 being greater than or equal to the first voltage threshold, the anti-backflow switch tube 1321 is turned on. At this time, the low-voltage battery 12 and the DC / DC circuit 130 are connected, so that the DC / DC circuit converts the low-voltage direct current provided by the low-voltage battery 12 into high-voltage direct current to charge the primary capacitor 134.

[0073] In some embodiments, the first voltage threshold is less than or equal to the rated voltage of the power supply 1331, and the first voltage threshold is less than the rated voltage of the low-voltage battery 12 (hereinafter referred to as the first preset voltage). In some embodiments, the difference between the first voltage threshold and the rated voltage of the low-voltage battery 12 is less than the preset value. It can be understood that the difference between the rated voltage of the low-voltage battery 12 and the first voltage threshold is the voltage across the anti-backfeed circuit 132, that is, when the voltage across the anti-backfeed circuit 132 is less than the preset value, the current flowing through the anti-backfeed circuit 132 is not enough to damage the anti-backfeed circuit 132, and the reliability of the on-board power supply device is high.

[0074] In a specific embodiment, when the electric vehicle starts, the anti-backflow circuit 132 and the slow-start circuit 133 are both in a disconnected state. The processor of the electric vehicle sends a high-voltage pre-charge instruction to the DC / DC circuit 130. After receiving the high-voltage pre-charge instruction, the DC / DC circuit 130 wakes up the power supply 1331 in the slow-start circuit 133. At this time, the slow-start circuit 133 starts to pre-charge the filter capacitor 131. The DC / DC circuit 130 detects the voltage across the filter capacitor 131 in real time, and when it detects that the voltage across the filter capacitor 131 is greater than or equal to the first voltage threshold, it turns on the anti-backflow switch tube 1321. At this time, the low-voltage direct current output by the low-voltage battery 12 can be converted by the DC / DC circuit 130 to charge the primary capacitor 134. Based on the above description of the first voltage threshold, when the voltage across the filter capacitor 131 is charged to a value greater than or equal to the first voltage threshold by the slow-start circuit, turning on the anti-backflow switch tube 1331 will not damage the anti-backflow switch tube 1331. After the primary capacitor 134 is fully charged, the DC / DC circuit 130 can control the anti-backflow circuit 132 and the soft-start circuit 133 to be turned off, and send a high-voltage pre-charging completion signal to the processor of the electric vehicle.

[0075] Continue to refer Figure 4 The anti-backfeed control circuit 1322 includes a first control subcircuit 1322a and a second control subcircuit 1322b. One end of the first control subcircuit 1322a is configured to receive a control signal Oring_CTL, and the other end of the first control subcircuit 1322a is connected to one end of the second control subcircuit 1322b. The other end of the second control subcircuit is connected to the gate of the anti-backfeed switch 1321. It will be appreciated that the first control subcircuit 1322a is configured to receive a control signal and, in response to the control signal Oring_CTL, control the on / off state of the anti-backfeed switch 1321 via the second control subcircuit 1322b.

[0076] Figure 5 2 is a schematic diagram of the structure of the second control circuit 1322b provided in an embodiment of the present application.

[0077] Among them, the second control circuit includes a first switch tube Q1 and a totem pole unit, the control electrode of the switch tube Q1 is connected to the first control sub-circuit 1322a, the first electrode of the switch tube Q1 is connected to one end of the filter capacitor 131, the second electrode of the switch tube Q1 is connected to the input end of the totem pole unit, and the output end of the totem pole unit is connected to the control electrode of the anti-backfeed switch tube 1321.

[0078] In some embodiments, during the process of power supply 1331 charging filter capacitor 131, in response to the voltage of filter capacitor 131 being less than a first voltage threshold, first switch Q1 is turned on, so that the totem pole unit drives anti-backfeed switch 1321 to turn off. In response to the voltage of filter capacitor 131 being greater than or equal to the first voltage threshold, switch Q1 is turned off, so that the totem pole unit drives anti-backfeed switch 1321 to turn on. When switch Q1 is turned off, the voltage difference between the control electrode and the first electrode of the first switch is less than or equal to the second voltage threshold.

[0079] The second voltage threshold is a very small voltage value, so that when the first switch tube Q1 is turned off, the voltage difference between the control electrode and the first electrode is a very small value, thereby reducing the risk of the first switch tube Q1 being broken down.

[0080] In these embodiments, in response to the voltage of the filter capacitor 131 being less than the first voltage threshold, the first control circuit 1322a is turned off and the first switch Q1 is turned on. In response to the voltage of the filter capacitor 131 being greater than or equal to the first voltage threshold, the first control circuit 1322a is turned on and the first switch Q1 is turned off.

[0081] According to an embodiment of the present application, by limiting the voltage difference between the base and the emitter when the first switch tube in the anti-backfeed control circuit is disconnected, the risk of the switch tube being broken down when the DC / DC circuit works in reverse is reduced, and the reliability of the on-board power supply device is high.

[0082] It can be understood that the switch tube Q1 can be a triode, in which case the control electrode of the switch tube Q1 is the base, the first electrode of the switch tube Q2 is the emitter, and the third electrode of the switch tube is the collector.

[0083] It can be understood that the embodiment of the present application does not limit the specific method of limiting the voltage difference between the control electrode and the first electrode of the first switch tube Q1.

[0084] In some embodiments, as Figure 5 As shown in (a) of FIG, one end of the first control subcircuit is connected to one end of the filter capacitor 131. Therefore, in response to the voltage of the filter capacitor 131 being greater than or equal to the first voltage threshold, the first control circuit 1322a is turned on, so that the switch tube Q1 is connected to one end of the filter capacitor 131. At this time, the voltage of the control electrode of the switch tube Q1 is slightly lower than the voltage of one end of the filter capacitor 131. At this time, the control electrode and the first electrode of the switch tube Q1 are both connected to one end of the filter capacitor 131. That is, the difference between the control electrode voltage of the switch tube Q1 and the first electrode voltage of the switch tube Q1 is close to the tube voltage drop of the switch tube Q8, and there is no risk of breakdown of the switch tube Q1.

[0085] In some embodiments, as Figure 5As shown in (b) of FIG. 1 , the second control subcircuit 1322b includes another diode D2, the cathode of which is connected to the control electrode of the switch Q1, and the anode of which is connected to the first electrode of the switch Q2. Therefore, in response to the voltage of the filter capacitor 131 being greater than or equal to the first voltage threshold, the switch Q1 is turned off, and the diode D2 clamps the voltage difference between the control electrode voltage of the switch Q1 and the first electrode voltage of the switch Q1. At this time, the voltage difference approaches the voltage drop across the diode D2, which is relatively small (typically 0.6V to 0.7V), and there is no risk of breakdown of the switch Q1.

[0086] According to the embodiments of the present application, the voltage difference between the base and the emitter when the first switch tube in the anti-backfeed control circuit is disconnected can be limited in a variety of ways, which is highly flexible and practical.

[0087] Figure 6 This is a circuit diagram of an anti-backfeed control circuit 1322 provided in an embodiment of the present application. Figure 6 The middle anti-backfeed switch tube 1321 is a MOSFET tube Q5. The following first describes the circuit of the second control sub-circuit 1322b.

[0088] like Figure 6 As shown, the second control subcircuit 1322b includes a switch tube Q1, a switch tube Q2, a resistor R2, a resistor R3, a resistor R4, and a totem pole unit. The control electrode of the switch tube Q1 is connected to the first electrode of the switch tube Q2, and then connected to one end of the resistor R2 and the first control subcircuit 1322a. The first electrode of the switch tube Q1 is connected to one end of the filter capacitor 131, and the second electrode of the switch tube Q1 is connected to the input end of the totem pole unit and one end of the resistor R3. The control electrode and the second electrode of the switch tube Q2 are short-circuited and then connected to the second electrode of the anti-backfeed switch tube 1321. At the same time, the other ends of the resistors R2 and R3 are connected to the positive electrode of the first battery V1. The voltage at one end of the filter capacitor 131 is represented as 12V_inner, the voltage at the other end of the filter capacitor 131 is represented as 12V_outer, and the positive electrode voltage of the first battery V1 is represented as 12V_inner_VCC.

[0089] During normal operation of the electric vehicle 10, the difference between the rated voltage of the first battery V1 and the voltage at the first terminal of the anti-backfeed circuit 130 during normal operation of the electric vehicle is greater than or equal to a third voltage threshold, which may be greater than or equal to 6V and less than or equal to 15V. For example, the third voltage threshold may be 12V. Furthermore, since the voltage at the first terminal of the anti-backfeed circuit 130 during normal operation of the electric vehicle 10 is slightly lower than the positive electrode voltage of the low-voltage battery 12, when the rated voltage of the low-voltage battery 12 is 12V, the rated voltage of the first battery V1 may be 24V.

[0090] Optionally, the switch tube Q1 may be an NPN transistor, and the switch tube Q2 may be a PNP transistor. In this case, the switch tube Q1 and the switch tube Q2 form an equivalent diode.

[0091] Continue to refer Figure 6 In some embodiments, the totem pole unit includes a switch tube Q3 and a switch tube Q4. The base of the switch tube Q3 and the base of the switch tube Q4 are connected to form the input of the totem pole unit, and the emitter of the switch tube Q3 and the emitter of the switch tube Q4 are connected to form the output of the totem pole unit. The input of the totem pole unit is connected to the second electrode of the switch tube Q1, and the output of the totem pole unit is connected to the control electrode of the anti-backfeed switch tube Q5. Specifically, the collector of the switch tube Q3 is connected to the positive electrode of the first battery V1 through the resistor R4, and the collector of the switch tube Q4 is connected to one end of the filter capacitor 131.

[0092] Continue to refer Figure 6 The first control subcircuit 1322a includes a first switch unit, a second switch unit, a first resistor R5, and a second resistor R6. The first end of the first switch unit receives the control signal Oring_CTL through the resistor R5, the second end of the first switch unit is connected to the positive electrode of the first battery V1 through the resistor R6, the third end of the first switch unit is used to connect to the first end of the second switch unit, and the fourth end of the first switch unit is grounded. The second end of the second switch unit is connected to the control electrode of the first switch tube, and the third end of the second switch unit is connected to one end of the filter capacitor 131 ( Figure 6 It can be understood that the resistors R5 and R6 are current limiting resistors.

[0093] In some embodiments, reference Figure 6The first switch unit includes a second switch tube Q6, a third switch tube Q7, a third resistor R7, and a fourth resistor R8. The control electrode of the switch tube Q6 is the first terminal of the first switch unit, the first terminal of the switch tube Q6 is connected to the control terminal of the switch tube Q7, and the second terminal of the switch tube Q6 is the fourth terminal of the first switch unit. The second terminal of the switch tube Q6 is short-circuited to the control electrode of the switch tube Q6 via resistor R7. The first terminal of the switch tube Q7 is the second terminal of the first switch unit, and the second terminal of the switch tube Q7 is the third terminal of the first switch unit. The control electrode of the switch tube Q7 is short-circuited to the first terminal of the switch tube Q7 via resistor R8. It can be understood that resistor R7 can prevent malfunction of the switch tube Q6, and resistor R8 can prevent malfunction of the switch tube Q7, thereby improving the reliability of the first switch unit.

[0094] Continue to refer Figure 6 The second switch unit includes a fourth switch tube Q8, a resistor R9, and a fifth resistor R10. The control electrode of the switch tube Q8 is connected to the first terminal of the second switch unit via resistor R9. The first terminal of the switch tube Q8 is connected to the second terminal of the second switch unit, and the second terminal of the switch tube Q8 is connected to the third terminal of the second switch unit. The control electrode of the switch tube Q8 is short-circuited to the second terminal of the switch tube Q8 via resistor R10. It can be understood that resistor R9 is a current-limiting resistor, and resistor R10 can prevent malfunction of the switch tube Q8, thereby improving the reliability of the second switch unit.

[0095] The switch tubes Q6 and Q8 may be MOSFETs, triodes, or thyristors, which are not limited in the present embodiment. For example, when the switch tubes Q6 and Q8 are MOS tubes, the control electrodes of the switch tubes Q6 and Q8 are gates, the first electrode of the switch tube Q6 is a drain, and the second electrode of the switch tubes Q6 and Q8 is a source.

[0096] The following combination Figure 6 The operation process of the anti-backfeed circuit 132 is described below.

[0097] During the reverse operation of the DC / DC circuit 130 , the soft-start circuit 133 first pre-charges the filter capacitor 131 .

[0098] In response to the voltage of filter capacitor 131 being less than the first voltage threshold, the control signal Oring_CTL received by switch Q6 through resistor R5 is a low-level signal (less than 3.3V), turning off switch Q6 and, in turn, turning off both switch Q7 and switch Q8. This is equivalent to the absence of first control subcircuit 1322a in anti-backfeed control circuit 1322, with only second control subcircuit 1322b existing. At this point, the voltage at the control electrode of switch Q1 is the same as the voltage at the first electrode of switch Q2, which is the sum of the positive electrode voltage of low-voltage battery 12 and the voltage drop across switch Q1. The voltage at the first electrode of switch Q1 is the voltage of filter capacitor 131. Therefore, the voltage between the control electrode and the first electrode of switch Q1 is greater than 0.7V, turning on switch Q1. At this time, the voltage at the input end of the totem pole unit (i.e., the base of the switch tube Q3 and the switch tube Q4) is pulled down to the voltage of the filter capacitor 131, and the totem pole unit is turned off and cannot drive the switch tube Q5 to turn on. That is, the anti-backfeed switch tube Q5 is turned off at this time.

[0099] In response to the voltage of the filter capacitor 131 being greater than or equal to the first voltage threshold, the control signal Oring_CTL received by the switch tube Q6 through the resistor R5 is a high-level signal (greater than or equal to 3.3V). At this time, the switch tube Q6 is turned on, thereby turning on both the switch tubes Q7 and Q8. The control electrode of the switch tube Q1 is connected to one end of the filter capacitor 131 through the switch tube Q8. At this time, the difference between the control electrode voltage of the switch tube Q1 and the first electrode voltage of the switch tube Q1 is less than 0.7V, and the switch tube Q1 is disconnected. At this time, the voltage of the input end of the totem pole unit (i.e., the base of the switch tube Q3 and the switch tube Q4) is pulled up by the first battery V1, and the totem pole is turned on. At this time, the gate voltage of the anti-backfeed switch tube Q5 is also the positive electrode voltage of the first battery V1, and the source voltage of the anti-backfeed switch tube Q5 is the voltage at one end of the filter capacitor. Since the voltage of the filter capacitor 131 is the first voltage threshold, and the first voltage threshold is lower than the rated voltage of the low-voltage battery 12, and the rated voltage of the low-voltage battery 12 is at least 6V lower than the positive voltage of the first battery, the difference between the gate voltage and the source voltage of the anti-backfeed switch tube is greater than 5V, and the anti-backfeed switch tube Q5 is turned on, so that the DC / DC circuit 130 can receive power from the low-voltage battery 12 through the anti-backfeed switch tube Q5 and supply it to the primary capacitor 134.

[0100] During forward operation, the DC / DC circuit 130 receives power from the high-voltage battery 11 and also supplies power to the low-voltage battery 12. During this process, the switch Q6 continuously receives the low-level control signal Oring_CTL through the resistor R5, turning off the switches Q6, Q7, and Q8 of the first control subcircuit 1322a. The second control subcircuit 1322b then independently controls the on / off switching of the anti-backfeed switch Q5.

[0101] In some embodiments, during forward operation of the DC / DC circuit 130, the voltage of the filter capacitor 131 gradually rises. The voltage at the control electrode of the switch Q1 is equal to the voltage of the low-voltage battery 12 plus the voltage drop across the switch Q2. The voltage at the first electrode of the switch Q1 is equal to the voltage of the filter capacitor 131. When the voltage of the filter capacitor 131 rises so that the voltage at the control electrode of the switch Q1 is less than 0.7V relative to the first electrode voltage, the switch Q2 is turned off. At this point, the voltage at the input end of the totem pole is equal to the positive voltage of the first battery V1, and the totem pole is turned on. At this point, the anti-backfeed switch Q5 is turned on, enabling the DC / DC circuit 130 to convert the high-voltage DC power into low-voltage DC power to charge the DC components of the electric vehicle 10, and the electric vehicle 10 begins normal operation.

[0102] In some embodiments, when a low-voltage side component (such as a transformer's secondary winding or a low-voltage side filter inductor) fails during forward operation of the DC / DC circuit 130, the voltage of the filter capacitor 131 gradually decreases. The control electrode voltage of the switch tube Q1 is the voltage of the low-voltage battery 12 plus the tube voltage drop of the switch tube Q2. The first electrode voltage of the switch tube Q1 is the voltage of the filter capacitor 131. When the voltage of the filter capacitor 131 decreases so that the control electrode voltage and the first electrode voltage of the switch tube Q1 are greater than 0.7V, the switch tube Q2 turns on. At this time, the voltage at the input end of the totem pole is pulled down to the voltage of the filter capacitor 131, the totem pole is turned off, and it is unable to drive the anti-backfeed switch tube Q5 to turn on. At this time, the anti-backfeed switch tube Q5 is turned off, thereby preventing the low-voltage battery 12 from being pulled down and the anti-backfeed switch tube Q5 from burning out.

[0103] According to the embodiment of the present application, the vehicle-mounted power supply device can not only realize energy conversion during the reverse operation of the DC / DC circuit, but also realize failure isolation of internal faults on the low-voltage side during the forward operation of the DC / DC circuit, and has high application reliability.

[0104] Figure 7 This is a circuit diagram of another anti-backfeeding control circuit 1322 provided in an embodiment of the present application. Figure 7 The anti-backflow switch tube 1321 is a MOSFET tube Q5, the control electrode of the switch tube Q5 is the gate, the first electrode is the source, and the second electrode is the drain. Figure 6 The relevant instructions are not repeated here.

[0105] refer to Figure 7 The first control sub-circuit 1322a includes a third switch unit, a sixth resistor R11, and a seventh resistor R12. A first end of the third switch unit receives a control signal Oring_CTL via the resistor R11, a second end of the third switch unit is connected to the control electrode of the switch tube Q1 via the resistor R12, and a third end of the third switch unit is grounded.

[0106] In one embodiment, the third switch unit may include a switch tube Q9, wherein the control electrode of the switch tube Q9 serves as the first end of the third switch unit, the first electrode of the switch tube Q9 serves as the second end of the third switch unit, and the second electrode of the switch tube Q9 serves as the third end of the third switch unit. The control electrode and the second electrode of the switch tube Q9 may be short-circuited by a resistor R13, which prevents malfunction of the switch tube Q9 and enhances reliability.

[0107] In one embodiment, the third switch unit may include multiple switch tubes Q9 connected in series, the first end of the third switch unit is the control electrode of each switch tube Q9, the second end of the third switch unit may be the first electrode of the first switch tube Q9 among the multiple switch tubes Q9, and the third end of the third switch unit is the second electrode of the last switch tube Q9 among the multiple switch tubes Q9.

[0108] According to the embodiment of the present application, the circuit structure of the first control sub-circuit 1322a is simple, highly reliable and practical.

[0109] Continue to refer Figure 7 In some embodiments, Figure 7 The second control subcircuit 1332b shown also includes a diode D2, the cathode of which is connected to the control electrode of the switch tube Q1, and the anode of which is connected to the first electrode of the switch tube Q1, thereby clamping the voltage of the control electrode and the voltage of the first electrode of the switch tube Q1 when the switch tube Q1 is disconnected, and there is no risk of breakdown of the switch tube Q1.

[0110] It is understood that in some embodiments, the second control subcircuit 1332b may also not include the diode D2. In this case, by designing the resistance ratio of the resistor R12 and the resistor R2, the voltage of the control electrode and the voltage of the first electrode of the switch tube Q1 can be limited when the switch tube Q1 is disconnected. For example, the rated voltage of the first battery V1 is 24V, and the rated voltage of the low-voltage battery 12 is 12V. In this case, the resistance values ​​of the resistor R12 and the resistor R2 can be set to be equal. Then, when the switch tube Q1 is disconnected, the voltage at the end of the resistor R12 connected to the control electrode of the switch tube Q1 is 12V. At this time, the control electrode of the switch tube Q1 and the first electrode of the switch tube Q1 are both close to 12V, and there is no risk of the switch tube Q1 being broken down.

[0111] The following combination Figure 7 The operation process of the anti-backfeed circuit 132 is described below.

[0112] During the reverse operation of the DC / DC circuit 130 , the soft-start circuit 133 first pre-charges the filter capacitor 131 .

[0113] In response to the voltage of filter capacitor 131 being less than the first voltage threshold, the control signal Oring_CTL received by switch Q9 via resistor R11 is a low-level signal, turning off switch Q9. At this point, only the second control subcircuit 1322b exists in the anti-backfeed control circuit 1322. At this point, switch Q1 is turned on, and the voltage at the input of the totem-pole unit (i.e., the base of switch Q3 and switch Q4) is pulled low. The totem-pole unit is turned off, unable to drive switch Q5 to turn on. Therefore, the anti-backfeed switch Q5 is turned off.

[0114] In response to the voltage of filter capacitor 131 being greater than or equal to the first voltage threshold, the control signal Oring_CTL received by switch Q9 via resistor R11 becomes a high-level signal, turning on switch Q9. At this point, the control electrode of switch Q1 can be grounded via switch Q9. Due to the clamping effect of diode D2 or the pull-down effect of appropriately matched resistor R12, the difference between the control electrode voltage of switch Q1 and the first electrode voltage of switch Q1 is less than 0.7V, turning off switch Q1. At this point, there is no risk of breakdown of switch Q1. At this point, the voltage at the input of the totem pole unit is pulled up by the first battery V1, turning on the totem pole and, in turn, driving the anti-backfeed switch Q5 to turn on, allowing the DC / DC circuit 130 to receive power from the low-voltage battery 12 through the anti-backfeed switch Q5 and supply it to the primary capacitor 134.

[0115] It can be understood that during the forward operation of the DC / DC circuit 130, the specific process of the second control subcircuit 1322b independently controlling the on and off of the anti-backfeed switch Q5 can be referred to. Figure 6 The relevant instructions are not repeated here.

[0116] According to the embodiments of the present application, it is possible to realize energy conversion during the reverse operation of the DC / DC circuit and to realize failure isolation of internal faults on the low-voltage side during the forward operation of the DC / DC circuit, thereby improving the reliability of the application of the on-board power supply device.

[0117] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A vehicle-mounted power supply device supporting reverse charging and slow start, characterized in that: The vehicle-mounted power supply device includes a filter capacitor, a DC conversion circuit, an anti-backflow circuit and a slow-start circuit, wherein: One end of the filter capacitor is used to connect an output end of the DC conversion circuit and is used to connect one end of the low-voltage battery through the anti-backflow circuit, and the other end of the filter capacitor is used to connect the other output end of the DC conversion circuit and the other end of the low-voltage battery; The soft-start circuit includes a power supply, and before the DC conversion circuit receives power from the low-voltage battery through the filter capacitor, the power supply first charges the filter capacitor.

2. The vehicle-mounted power supply device according to claim 1, characterized in that: The soft-start circuit further includes a diode and / or a current-limiting resistor, and the one power supply is used to connect to one end of the filter capacitor through the diode and / or the current-limiting resistor.

3. The vehicle-mounted power supply device according to claim 1, characterized in that: The vehicle-mounted power supply device further includes a primary capacitor, one end of the primary capacitor is used to connect to one input end of the DC conversion circuit, and the other end of the primary capacitor is used to connect to the other input end of the DC conversion circuit; In the process of charging the filter capacitor by one power supply, In response to the voltage of the filter capacitor being greater than or equal to a first voltage threshold, the anti-backfeed circuit is turned on, so that the DC conversion circuit converts the low-voltage DC power provided by the low-voltage battery into high-voltage DC power to charge the primary capacitor.

4. The vehicle-mounted power supply device according to claim 3, characterized in that: During the process in which the DC conversion circuit is used to convert high-voltage DC power into low-voltage DC power for charging the low-voltage battery, the one power supply stops charging the filter capacitor.

5. The vehicle-mounted power supply device according to claim 3 or 4, characterized in that: The anti-backfeed circuit includes an anti-backfeed switch tube and an anti-backfeed control circuit. The anti-backfeed control circuit includes a first control subcircuit and a second control subcircuit. The first control subcircuit is used to control the conduction and shutdown of the anti-backfeed switch tube through the second control subcircuit by receiving a control signal.

6. The vehicle-mounted power supply device according to claim 5, characterized in that: The second control subcircuit includes a first switch tube and a totem pole unit. In the process of charging the filter capacitor by one power supply, In response to the voltage of the filter capacitor being less than the first voltage threshold, the first switch tube is turned on, so that the totem pole unit drives the anti-backfeed switch tube to be turned off; In response to the voltage of the filter capacitor being greater than or equal to the first voltage threshold, the first switch tube is turned off, so that the totem pole unit drives the anti-backfeed switch tube to be turned on; wherein, When the first switch tube is turned off, a voltage difference between the control electrode and the first electrode of the first switch tube is less than or equal to a second voltage threshold.

7. The vehicle-mounted power supply device according to claim 6, characterized in that: The control electrode of the first switch tube is used to connect to the first control sub-circuit, the first electrode of the first switch tube is used to connect to one end of the filter capacitor, and one end of the first control sub-circuit is used to connect to one end of the filter capacitor; In response to the voltage of the filter capacitor being greater than or equal to the first voltage threshold, the first control subcircuit is turned on, so that one end of the filter capacitor is connected to the control electrode of the first switch tube.

8. The vehicle-mounted power supply device according to claim 7, characterized in that: The first control subcircuit includes a first switch unit, a second switch unit, a first resistor and a second resistor, wherein: The first end of the first switch unit is used to receive the control signal through a first resistor, the second end of the first switch unit is used to connect to the positive electrode of the first battery through a second resistor, the third end of the first switch unit is used to connect to the first end of the second switch unit, and the fourth end of the first switch unit is grounded; The second end of the second switch unit is used to connect to the control electrode of the first switch tube, and the third end of the second switch unit is used to connect to one end of the filter capacitor.

9. The vehicle-mounted power supply device according to claim 8, characterized in that: The first switch unit includes a second switch tube, a third switch tube, a third resistor and a fourth resistor, and the second switch unit includes a fourth switch tube and a fifth resistor; The control electrode of the second switching tube is the first end of the first switching unit, the first electrode of the second switching tube is used to connect to the control end of the third switching tube, and the second electrode of the second switching tube is the fourth end of the first switching unit, wherein the second electrode of the second switching tube is short-circuited with the control electrode of the second switching tube via the third resistor; The first terminal of the third switch tube is the second end of the first switch unit, and the second terminal of the third switch tube is the third end of the first switch unit, wherein the control terminal of the third switch tube is short-circuited with the first terminal of the third switch tube through the fourth resistor; The control electrode of the fourth switch tube is the first end of the second switch unit, the first electrode of the fourth switch tube is the second end of the second switch unit, and the second electrode of the fourth switch tube is the third end of the second switch unit, wherein the control electrode of the fourth switch tube is short-circuited with the second electrode of the fourth switch tube through the fifth resistor.

10. The vehicle-mounted power supply device according to claim 6, characterized in that: The second control sub-circuit further includes another diode, wherein the cathode of the another diode is used to connect to the control electrode of the first switch tube, and the anode of the another diode is used to connect to the first electrode of the first switch tube.

11. The vehicle-mounted power supply device according to claim 10, characterized in that: The first control subcircuit includes a third switch unit, a sixth resistor and a seventh resistor. The first end of the third switch unit is used to receive the control signal through the sixth resistor, the second end of the third switch unit is used to connect to the control electrode of the first switch tube through the seventh resistor, and the third end of the third switch unit is grounded.

12. An electric vehicle, characterized in that: It includes a low-voltage battery and an on-board power supply device, wherein the on-board power supply device includes a filter capacitor, a DC conversion circuit, an anti-backflow circuit and a slow-start circuit, wherein: One end of the filter capacitor is used to connect an output end of the DC conversion circuit and is used to connect one end of the low-voltage battery through the anti-backflow circuit, and the other end of the filter capacitor is used to connect the other output end of the DC conversion circuit and the other end of the low-voltage battery; The soft-start circuit includes a power supply, and before the DC conversion circuit receives power from the low-voltage battery through the filter capacitor, the power supply first charges the filter capacitor.

13. The electric vehicle according to claim 12, characterized in that: The vehicle-mounted power supply device further includes a primary capacitor, one end of the primary capacitor is used to connect to one input end of the DC conversion circuit, and the other end of the primary capacitor is used to connect to the other input end of the DC conversion circuit; In the process of charging the filter capacitor by one power supply, In response to the voltage of the filter capacitor being greater than or equal to a first voltage threshold, the anti-backfeed circuit is turned on, so that the DC conversion circuit converts the low-voltage DC power provided by the low-voltage battery into high-voltage DC power to charge the primary capacitor.

14. The electric vehicle according to claim 12, characterized in that: The electric vehicle also includes a high-voltage battery. When the DC conversion circuit is used to convert the high-voltage direct current provided by the high-voltage battery into low-voltage direct current to charge the low-voltage battery, the one power supply stops charging the filter capacitor.

15. The electric vehicle according to claim 13, characterized in that: The vehicle-mounted power supply device further includes an anti-backfeeding control circuit, which includes a first control subcircuit and a second control subcircuit, wherein the first control subcircuit is configured to control the on / off of the anti-backfeeding circuit through the second control subcircuit by receiving a control signal; wherein, The second control subcircuit includes a first switch tube and a totem pole unit. In the process of charging the filter capacitor by one power supply, In response to the voltage of the filter capacitor being less than the first voltage threshold, the first switch tube is turned on, so that the totem pole unit drives the anti-backfeed circuit to turn off; In response to the voltage of the filter capacitor being greater than or equal to the first voltage threshold, the first switch tube is turned off, so that the totem pole unit drives the anti-backfeed circuit to be turned on; wherein, When the first switch tube is turned off, a voltage difference between the control electrode and the first electrode of the first switch tube is less than or equal to a second voltage threshold.

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