Vehicle and low-voltage power supply circuit thereof

Abstract

The utility model discloses a vehicle and its low-voltage power supply circuit, the low-voltage power supply circuit comprises: a voltage conversion unit and a first power supply unit, the voltage conversion unit is configured to generate low-voltage electricity according to high-voltage electricity output by a power battery, the first power supply unit is configured to store the low-voltage electricity, the low-voltage power is used for supplying power to the low-voltage device; the second power supply unit is configured to generate low-voltage power according to the high-voltage power so as to supply power to the low-voltage device; the first controllable switch unit is connected with the voltage conversion unit and the second power supply unit and suitable for being connected with a power battery, and the first controllable switch unit is configured to stop providing high-voltage electricity for the voltage conversion unit under the condition that a control instruction sent by a vehicle controller is received; and the vehicle controller generates a control instruction when determining that the vehicle enters the dormant state. The circuit solves the problem of keeping the electric quantity of the low-voltage storage battery.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a vehicle and its low-voltage power supply circuit. Background Technology

[0002] New energy vehicles are powered by high-voltage battery packs. Voltage conversion components transform the high-voltage electricity from the battery packs into low-voltage electricity to power low-voltage devices in the vehicle. The low-voltage power supply circuit of new energy vehicles requires a low-voltage battery to store electrical energy and supply power to low-voltage devices when the voltage conversion components are not operating.

[0003] When a new energy vehicle is locked and the power is off, the high-voltage power supply system cuts off the power supply, the voltage conversion components stop working, and a small number of components inside the vehicle remain operational, requiring power from the low-voltage battery. However, when the vehicle is parked for an extended period, the low-voltage battery will deplete, failing to meet the power supply needs when the vehicle is powered on again. Utility Model Content

[0004] This utility model aims to at least partially solve one of the technical problems in the related art. Therefore, the first objective of this utility model is to provide a low-voltage power supply circuit for a vehicle, in which a second power supply unit, after the vehicle enters a sleep state, can work with the first power supply unit to supply power to low-voltage devices, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the low-voltage battery's charge. This ensures that the first power supply unit can meet the vehicle's power supply needs when the vehicle is powered on again.

[0005] The second objective of this utility model is to provide a vehicle.

[0006] To achieve the above objectives, a low-voltage power supply circuit for a vehicle is provided according to a first aspect of the present invention, comprising: a voltage conversion unit and a first power supply unit, the first power supply unit being connected to the voltage conversion unit and adapted to connect to low-voltage devices; the voltage conversion unit being configured to generate low-voltage electricity based on the high-voltage electricity output from the power battery; the first power supply unit being configured to store the low-voltage electricity and use the low-voltage electricity to power the low-voltage devices; a second power supply unit, adapted to connect to the low-voltage devices, the second power supply unit being configured to generate low-voltage electricity based on the high-voltage electricity to power the low-voltage devices; and a first controllable switch unit, the first controllable switch unit being connected to the voltage conversion unit and the second power supply unit respectively and adapted to connect to the power battery; the first controllable switch unit being configured to stop supplying high-voltage electricity to the voltage conversion unit and supply high-voltage electricity to the second power supply unit upon receiving a control command sent by the vehicle controller, wherein the vehicle controller generates the control command when it determines that the vehicle has entered a sleep state.

[0007] The low-voltage power supply circuit according to an embodiment of the present invention includes a voltage conversion unit, a first power supply unit, a second power supply unit, and a first controllable switch unit. The first power supply unit is connected to the voltage conversion unit and is adapted to connect to low-voltage devices. The voltage conversion unit is configured to generate low-voltage electricity based on the high-voltage electricity output from the power battery. The first power supply unit is configured to store the low-voltage electricity and use it to power the low-voltage devices. The second power supply unit is adapted to connect to the low-voltage devices and is configured to generate low-voltage electricity based on the high-voltage electricity to power the low-voltage devices. The first controllable switch unit is connected to both the voltage conversion unit and the second power supply unit and is adapted to connect to the power battery. The first controllable switch unit is configured to stop supplying high-voltage electricity to the voltage conversion unit and supply high-voltage electricity to the second power supply unit upon receiving a control command from the vehicle controller. The vehicle controller generates the control command when it determines that the vehicle has entered a sleep state. Therefore, the second power supply unit can supply power to the low-voltage devices together with the first power supply unit after the vehicle enters the sleep state, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the power of the low-voltage battery. In this way, the first power supply unit can meet the power supply needs of the vehicle when it is powered on again.

[0008] According to one embodiment of the present invention, the second power supply unit includes: a transformer, one end of the primary winding of the transformer being connected to a first controllable switching unit; a first switching device, a first end of the first switching device being connected to the other end of the primary winding, and a second end of the first switching device being grounded; a control module, the control module being connected to the control terminal of the first switching device and adapted to be connected to a vehicle controller, the control module being configured to control the switching of the first switching device upon receiving a start command sent by the vehicle controller, so as to couple the high-voltage electrical energy provided by the transformer from the primary winding to the secondary winding, wherein the vehicle controller sends a start command to the control module after sending a control command to the first controllable switching unit, and enters a sleep state after sending the start command; and an output module, the output module being connected to the secondary winding and adapted to be connected to a low-voltage device, the output module being configured to output low-voltage electricity according to the electricity coupled to the secondary winding.

[0009] According to one embodiment of the present invention, the low-voltage power supply circuit further includes a second controllable switch unit. One end of the second controllable switch unit is connected to the first power supply unit, and the other end of the second controllable switch unit is connected to the output module and is adapted to connect to low-voltage devices. The control terminal of the second controllable switch unit is connected to the control module. The control module is further configured to control the second controllable switch unit according to the output voltage of the first power supply unit, so that the first power supply unit stops supplying power to the low-voltage devices, or charges the first power supply unit according to the electrical energy output by the output module.

[0010] According to one embodiment of the present invention, the second power supply unit further includes a sampling module. The input terminal of the sampling module is connected to the first power supply unit, and the output terminal of the sampling module is connected to the control module. The sampling module is configured to sample the output voltage of the first power supply unit to obtain first voltage information and provide the first voltage information to the control module. The control module is further configured to control the second controllable switch unit to disconnect when the first voltage information is greater than a preset voltage threshold, so that the first power supply unit stops supplying power to the low-voltage device, and to control the second controllable switch unit to turn on when the first voltage information is less than or equal to the preset voltage threshold, so that the output module charges the first power supply unit.

[0011] According to one embodiment of the present invention, the control module includes: a sampling submodule connected to the output module, configured to sample the output voltage of the output module to obtain second voltage information; a controller connected to the sampling submodule and adapted to be connected to a vehicle controller, configured to generate a control signal for a first switching device based on the second voltage information upon receiving a start command, so as to maintain the output voltage of the output module at a preset voltage value; and an isolation transmission submodule connected to the controller and the control terminals of the first switching device, configured to transmit the control signal to the control terminal of the first switching device in an isolated manner.

[0012] According to one embodiment of the present invention, the isolation transmission submodule includes an optocoupler. The anode of the light-emitting part of the optocoupler is connected to the controller, the cathode of the light-emitting part of the optocoupler is grounded, one end of the light-receiving part of the optocoupler is adapted to input a first preset power supply, and the other end of the light-receiving part of the optocoupler is connected to the control terminal of the first switching device.

[0013] According to one embodiment of the present invention, the second power supply unit further includes a power generation module, which is connected to the light-receiving part of the optocoupler. The power generation module includes an auxiliary winding, which is disposed on the primary side of the transformer. The power generation module is configured to generate a first preset power supply based on the electrical energy coupled to the auxiliary winding.

[0014] According to one embodiment of the present invention, the first controllable switch unit includes: a first switch, one end of which is adapted to be connected to the positive terminal of the power battery, and the other end of which is connected to a voltage conversion unit; a second switch, one end of which is adapted to be connected to the negative terminal of the power battery, and the other end of which is connected to the voltage conversion unit; and a third switch, one end of which is adapted to be connected to the positive terminal of the power battery, and the other end of which is connected to a second power supply unit.

[0015] According to one embodiment of the present invention, the first power supply unit includes a supercapacitor.

[0016] To achieve the above objectives, a vehicle is provided according to a second aspect of the present invention, including the low-voltage power supply circuit of any of the foregoing embodiments.

[0017] According to the vehicle of this utility model embodiment, by adopting the above-mentioned low-voltage power supply circuit, the second power supply unit can supply power to the low-voltage devices together with the first power supply unit after the vehicle enters the sleep state, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the power of the low-voltage battery. In this way, the first power supply unit can meet the power supply needs of the vehicle when it is powered on again.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the low-voltage power supply circuit of a vehicle according to an embodiment of the present invention;

[0020] Figure 2 This is a circuit diagram of the second power supply unit according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of a second controllable switching unit according to an embodiment of the present invention;

[0022] Figure 4 This is a circuit diagram of the second power supply unit according to another embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of a first controllable switch unit according to an embodiment of the present invention. Detailed Implementation

[0024] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0025] It should be noted that this application is based on the inventor's understanding and research into the following issues:

[0026] When a new energy vehicle is locked and the power is off, the high-voltage power supply system cuts off the power, the voltage conversion component stops working, and most components of the vehicle are in a shutdown or standby state. A few components remain operational, such as the T_BOX (Telematics BOX), sentry camera, and remote door lock. The power consumed by these operational and standby components must be supplied by the low-voltage battery. When the vehicle is parked for an extended period, the battery needs continuous power, which can lead to battery depletion. To ensure sufficient battery charge during long-term parking and to meet the power demands of the next vehicle power-on, two methods are typically used: one is to increase the battery capacity to accommodate the discharge during long-term parking; the other is to periodically activate the high-voltage conversion component to charge the battery and meet the vehicle's power requirements.

[0027] The first approach is rather passive. On the one hand, the increased capacity may not meet the needs of long-term parking. On the other hand, increasing the battery capacity leads to an increase in the weight and volume of the battery, which in turn increases the overall vehicle layout space and energy consumption, and also increases the cost of the vehicle.

[0028] The second method is implemented as follows: After the vehicle is parked, powered off, and locked, and the vehicle network enters a sleep state, the T_BOX starts timing and wakes up every preset time (e.g., 6 hours) to check the terminal voltage of the low-voltage battery. If the voltage is higher than the preset charging voltage, the T_BOX remains in sleep mode; if the voltage is lower than the preset charging voltage, the T_BOX sends a charging request to the VCU (Vehicle Control Unit). The VCU wakes up the BMS (Battery Management System), closes the high-voltage relay, and then wakes up the voltage conversion component, issuing an enable command to start charging the battery. This method requires continuous monitoring of the battery voltage. When the battery voltage is lower than the preset charging voltage, the VCU needs to be woken up, which in turn wakes up the BMS and voltage conversion component, issuing a working command. The BMS closes the relay, and the voltage conversion component starts working. The charging process requires the VCU, BMS, and main relay to operate continuously. On the one hand, this process increases the system's additional power consumption; on the other hand, after the relay closes, some high-voltage electrical components in a sleep state will become energized, posing a certain safety hazard.

[0029] Based on this, the present invention provides a vehicle and its low-voltage power supply circuit. After the vehicle enters a sleep state, the second power supply unit can supply power to the low-voltage devices together with the first power supply unit, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the power of the low-voltage battery. In this way, when the vehicle is powered on again, the first power supply unit can meet the power supply needs of the vehicle.

[0030] The vehicle and its low-voltage power supply circuit according to an embodiment of the present invention are described below with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic diagram of the low-voltage power supply circuit of a vehicle according to an embodiment of the present invention. Figure 1 As shown, the low-voltage power supply circuit 100 includes a voltage conversion unit 10, a first power supply unit 20, a second power supply unit 30, and a first controllable switch unit 40.

[0032] The first power supply unit 20 is connected to the voltage conversion unit 10 and is adapted to connect to the low-voltage device 200. The voltage conversion unit 10 is configured to generate low-voltage electricity based on the high-voltage electricity output from the power battery 300. The first power supply unit 20 is configured to store the low-voltage electricity and use it to power the low-voltage device 200. The second power supply unit 30 is adapted to connect to the low-voltage device 200 and is configured to generate low-voltage electricity based on the high-voltage electricity to power the low-voltage device 200. The first controllable switch unit 40 is connected to the voltage conversion unit 10 and the second power supply unit 30 respectively and is adapted to connect to the power battery 300. The first controllable switch unit 40 is configured to stop supplying high-voltage electricity to the voltage conversion unit 10 and supply high-voltage electricity to the second power supply unit 30 when it receives a control command sent by the vehicle controller 312 (not shown). The vehicle controller 312 generates the control command when it determines that the vehicle has entered a sleep state.

[0033] Specifically, the vehicle also includes a high-voltage device 400 and a vehicle controller (VCU). The first controllable switching unit 40 is also adapted to connect to the high-voltage device 400, which includes a motor controller, a DC-AC converter, a car heater, an air compressor, and other devices. When the vehicle is powered on, the first controllable switching unit 40 provides high-voltage electricity to the voltage conversion unit 10. The vehicle controller controls the voltage conversion unit 10 to generate low-voltage electricity (e.g., 24V) based on the high-voltage electricity. The first power supply unit 20 stores the low-voltage electricity and supplies power to the low-voltage device 200. At the same time, the power battery 300 supplies power to the high-voltage device 400 through the first controllable switching unit 40. The voltage of the power battery 300 is between 600V and 900V. After the vehicle is powered off and locked, the vehicle controller sends a shutdown command or a sleep command to the high-voltage device 400 and some of the low-voltage devices 200. Except for the T_BOX and some of the low-voltage devices 200, all other devices enter a sleep or shutdown state. At this time, the vehicle controller controls the voltage conversion unit 10 to stop working, and the first power supply unit 20 supplies power to the low-voltage device 200 in the working state according to the stored electrical energy. At the same time, the vehicle controller generates a control command and controls the first controllable switch unit 40 according to the control command, so that the first controllable switch unit 40 stops supplying high voltage to the voltage conversion unit 10 and supplies high voltage to the second power supply unit 30. The second power supply unit 30 can continuously generate low voltage according to the high voltage output of the power battery 300 and supply power to the low-voltage device 200 in the working state.

[0034] In one optional embodiment, the voltage conversion unit 10 is a voltage conversion component, and the first power supply unit 20 is a low-voltage battery.

[0035] In the above embodiment, the second power supply unit can supply power to the low-voltage devices together with the first power supply unit after the vehicle enters the sleep state, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the power of the low-voltage battery. In this way, the first power supply unit can meet the power supply needs of the vehicle when it is powered on again.

[0036] In some embodiments, such as Figure 2As shown, the second power supply unit 30 includes: a transformer T, a first switch S1 device Q1, a control module 31, and an output module 32. One end of the primary winding N1 of the transformer T is connected to the first controllable switch unit 40; the first end of the first switch S1 device Q1 is connected to the other end of the primary winding N1, and the second end of the first switch S1 device Q1 is grounded. The control module 31 is connected to the control terminal of the first switch S1 device Q1 and is adapted to connect to a vehicle controller. The control module 31 is configured to control the switching of the first switch S1 device Q1 upon receiving a start command from the vehicle controller, so that the high-voltage power supplied by the transformer T can be coupled from the primary winding N1 to the secondary winding N2. The vehicle controller sends a start command to the control module 31 after sending a control command to the first controllable switch unit 40, and enters a sleep state after sending the start command. The output module 32 is connected to the secondary winding N2 and is adapted to connect to a low-voltage device 200. The output module 32 is configured to output low-voltage power based on the power coupled to the secondary winding N2.

[0037] Specifically, after the vehicle controller generates a control command and outputs the control command to the first controllable switch unit 40, the primary winding N1 is energized. The vehicle controller sends a start command to the control module 31, the control module 31 starts working, and the vehicle controller enters a sleep state. After receiving the start command, the control module 31 outputs a control signal to the control terminal of the first switch device Q1 to switch the first switch device Q1. The control signal is a PWM (Pulse Width Modulation) signal, and the first switch device Q1 can be a high-voltage NMOS (N-Metal-Oxide-Semiconductor) transistor. When the first switch device Q1 is on, the primary winding N1 stores electrical energy. When the first switch device Q1 is off, the electrical energy stored in the primary winding N1 is coupled to the secondary winding N2. By adjusting the turns ratio of the transformer T, the output voltage of the output module 32 can be adjusted so that the output module 32 outputs low-voltage electricity.

[0038] Furthermore, the second power supply unit 30 also includes a first capacitor C1, a first resistor R1, a second capacitor C2, a first diode D1, a second diode D2, a second resistor R2, and a third resistor R3. One end of the first capacitor C1 is adapted to receive a high-voltage positive voltage HV+, and the other end of the first capacitor C1 is adapted to receive a high-voltage negative voltage HV-, and is grounded. That is, when the first controllable switch unit 40 provides high-voltage electricity to the second power supply unit 30, one end of the first capacitor C1 is adapted to connect to the positive terminal of the power battery 300, and the other end of the first capacitor C1 is adapted to connect to the negative terminal of the power battery 300. One end of the first resistor R1 is adapted to connect to the positive terminal of the power battery 300. One end of the second capacitor C2 is connected to one end of the first resistor R1, and the other end of the second capacitor C2 is connected to the first resistor R3. The other end of a resistor R1 is connected to a first diode D1 and a second capacitor C2 connected in parallel. The cathode of the second diode D2 is connected to the other end of the first resistor R1, and the anode of the second diode D2 is connected to the other end of the primary winding N1 and the first end of the first switch S1 device Q1. The second resistor R2 is placed between the control module 31 and the control terminal of the first switch S1 device Q1 to limit the current of the control signal output by the control module 31. One end of the third resistor R3 is connected to the control terminal of the first switch S1 device Q1, and the other end of the third resistor R3 is grounded. When the control module 31 does not output a control signal, the third resistor R3 pulls the control terminal of the first switch S1 device Q1 to a low level so that the first switch S1 device Q1 remains in the off state.

[0039] In one optional implementation, the terminals of the primary winding N1 and the secondary winding N2 are opposite in direction, so that the primary winding N1 can couple electrical energy to the secondary winding N2 when the first switch S1 device Q1 is turned off. Further, the output module 32 includes a third diode D3, a third capacitor C3, and a fourth capacitor C4. The anode of the third diode D3 is connected to one end of the secondary winding N2, and the cathode of the third diode D3 is connected to one end of the third capacitor C3, which is also the power output terminal of the output module 32. The other end of the third capacitor C3 is connected to the other end of the secondary winding N2 and grounded. The fourth capacitor C4 is connected in parallel with the third capacitor C3.

[0040] It should be noted that the second power supply unit 30 can also be a forward switching power supply, that is, the same-name terminals of the primary winding N1 and the secondary winding N2 have the same direction. In this case, the structure of the output module 32 is different from the above structure.

[0041] In the above embodiment, the second power supply unit is always connected to the power battery after the vehicle is powered off. Therefore, the second power supply unit can continuously generate low voltage based on the high voltage of the power battery. Moreover, the second power supply unit adopts the above circuit structure, which has low static power consumption and will not increase the power consumption of the vehicle.

[0042] In some embodiments, such as Figure 3 As shown, the low-voltage power supply circuit 100 also includes a second controllable switch unit 50. One end of the second controllable switch unit 50 is connected to the first power supply unit 20, and the other end of the second controllable switch unit 50 is connected to the output module 32 and is adapted to connect to the low-voltage device 200. The control terminal of the second controllable switch unit 50 is connected to the control module 31. The control module 31 is also configured to control the second controllable switch unit 50 according to the output voltage of the first power supply unit 20, so that the first power supply unit 20 stops supplying power to the low-voltage device 200, or charges the first power supply unit 20 according to the electrical energy output by the output module 32.

[0043] Specifically, the second controllable switch unit 50 is located at the output terminal of the first power supply unit 20. It can be used to control whether the first power supply unit 20 supplies power to the low-voltage device 200. Simultaneously, the second controllable switch unit 50 can also be used to control whether the output module 32 supplies low-voltage power to the first power supply unit 20 to charge it. When the second controllable switch unit 50 is open, the first power supply unit 20 stops supplying power to the low-voltage device 200, and the second power supply unit 30 supplies power to the low-voltage device 200 alone. When the second controllable switch unit 50 is open, the first power supply unit 20 and the second power supply unit 30 supply power to the low-voltage device 200 respectively, while the second power supply unit 30 charges the first power supply unit 20, thereby replenishing the power supply unit 20.

[0044] In one alternative implementation, the second controllable switching unit 50 can be a relay, a switching transistor, etc., and there are no specific limitations here.

[0045] In the above embodiments, by controlling the second controllable switch unit, the second power supply unit can supply power to the low-voltage devices independently and replenish the first power supply unit. Therefore, only the low-voltage battery that meets the vehicle's operating requirements can be selected, thereby further reducing the capacity of the low-voltage battery, which in turn reduces the overall vehicle layout space and energy consumption, and lowers the vehicle cost.

[0046] In some embodiments, such as Figure 4As shown, the second power supply unit 30 also includes a sampling module 33. The input terminal of the sampling module 33 is connected to the first power supply unit 20, and the output terminal of the sampling module 33 is connected to the control module 31. The sampling module 33 is configured to sample the output voltage of the first power supply unit 20 to obtain first voltage information and provide the first voltage information to the control module 31. The control module 31 is also configured to control the second controllable switch unit 50 to disconnect when the first voltage information is greater than a preset voltage threshold, so that the first power supply unit 20 stops supplying power to the low-voltage device 200, and to control the second controllable switch unit 50 to turn on when the first voltage information is less than or equal to the preset voltage threshold, so that the output module 32 charges the first power supply unit 20.

[0047] Specifically, the sampling module 33 samples the output voltage of the first power supply unit 20 to obtain first voltage information, and the control module 31 compares the first voltage information with a preset voltage threshold. If the first voltage information is greater than the preset voltage threshold, it indicates that the output voltage of the first power supply unit 20 exceeds the safety threshold. The control module 31 controls the second controllable switch unit 50 to open, and the first power supply unit 20 stops supplying power to the low-voltage device 200, thus realizing the switching of power supply to the pneumatic device. If the first voltage information is less than or equal to the preset voltage threshold, it indicates that the power of the first power supply unit 20 is low. The output module 32 needs to supply power not only to the low-voltage device 200 but also to charge the first power supply unit 20.

[0048] Furthermore, when the output module 32 is charging the first power supply unit 20, the control module 31 can also generate a PWM signal based on the first voltage information to periodically switch the second controllable switching unit 50, thereby achieving controllable charging power.

[0049] In one optional implementation, the sampling module 33 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first operational amplifier OP1. The fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are connected in series and placed between the output terminal of the first power supply unit 20 and ground. The positive input terminal of the first operational amplifier OP1 is connected to the first node J1, which is the connection point of the fifth resistor R5 and the sixth resistor R6. The negative input terminal of the first operational amplifier OP1 is connected to the output terminal of the first operational amplifier OP1, and the output terminal of the first operational amplifier OP1 is connected to the control module 31.

[0050] In the above embodiments, the control module is also used to control the replenishment of power to the first power supply unit. Therefore, the vehicle controller, BMS and voltage conversion group can continue to remain in a dormant state, thereby reducing vehicle energy consumption and solving the problem of safety hazards caused by the power-on of some high-voltage electrical appliances that are in a dormant state during replenishment.

[0051] In some embodiments, such as Figure 4 As shown, the control module 31 includes a sampling submodule 311, a controller 312, and an isolation transmission submodule 313. The sampling submodule 311 is connected to the output module 32 and is configured to sample the output voltage of the output module 32 to obtain the second voltage information V_24V. The controller 312 is connected to the sampling submodule 311 and is adapted to be connected to the vehicle controller. The controller 312 is configured to generate a control signal PWM for the first switch S1 device Q1 based on the second voltage information V_24V when a start command is received, so that the output voltage of the output module 32 is maintained at a preset voltage value. The isolation transmission submodule 313 is connected to the control terminals of the controller 312 and the first switch S1 device Q1, respectively. The isolation transmission submodule 313 is configured to transmit the control signal PWM to the control terminal of the first switch S1 device Q1 in isolation.

[0052] In other words, the sampling submodule 311 samples the output voltage of the output module 32 to obtain the second voltage information V_24V. The controller 312 generates a control signal based on the second voltage information V_24V to maintain the output voltage of the output module 32 at a preset voltage value (e.g., 24V). The controller 312 can be a microcontroller or a DSP (Digital Signal Processing) chip. Because the first switch S1 device Q1 is located on the high-voltage side, while the controller 312 is on the low-voltage side, the controller 312 cannot directly provide the control signal PWM to the first switch S1 device Q1. Therefore, the isolation transmission submodule 313 is needed to transmit the control signal PWM to the first switch S1 device Q1 in an isolated manner.

[0053] In one optional implementation, the sampling submodule 311 and the sampling module 33 can adopt the same circuit structure. The sampling submodule 311 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a second operational amplifier OP2. The seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 are connected in series and placed between the output terminal of the output module 32 and ground. The positive input terminal of the second operational amplifier OP2 is connected to the second node J2, which is the connection point of the eighth resistor R8 and the ninth resistor R9. The negative input terminal of the second operational amplifier OP2 is connected to the output terminal of the first operational amplifier OP1. The output terminal of the second operational amplifier OP2 is connected to the second input pin of the controller 312.

[0054] The controller 312 includes a first input pin, a second input pin, a first communication pin, a second communication pin, a first control pin, and a second control pin. The first input pin is connected to the first operational amplifier OP1 and is suitable for inputting the first voltage information V_KL30. The second input pin is connected to the second operational amplifier OP2 and is suitable for inputting the second voltage information V_24V. The first and second communication pins are suitable for communication connection with the vehicle controller. The first communication pin is suitable for inputting / outputting a CANH signal, and the second communication pin is suitable for inputting / outputting a CANL signal. The first control pin is suitable for outputting the control signal PWM of the first switch S1 device Q1, and the second control pin is suitable for outputting the control signal control of the second controllable switch unit 50.

[0055] In some embodiments, such as Figure 4 As shown, the isolation transmission submodule 313 includes an optocoupler U1. The anode of the light-emitting part of the optocoupler U1 is connected to the controller 312, the cathode of the light-emitting part of the optocoupler U1 is grounded, one end of the light-receiving part of the optocoupler U1 is adapted to input a first preset power supply VDD, and the other end of the light-receiving part of the optocoupler U1 is connected to the control terminal of the first switch S1 device Q1.

[0056] Specifically, when the control signal PWM is high, the light-emitting part of the optocoupler U1 emits light, which turns on the light-receiving part of the optocoupler U1, and the output signal Drive of the optocoupler U1 is high; when the control signal PWM is low, the light-emitting part of the optocoupler U1 is turned off, and the light-receiving part of the optocoupler U1 is also turned off, so the output signal Drive of the optocoupler U1 is low.

[0057] Furthermore, the isolation transmission submodule 313 also includes a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12. One end of the tenth resistor R10 is connected to the anode of the light-emitting part of the optocoupler U1, and the other end of the tenth resistor R10 is adapted to input the second preset power supply VCC. The tenth resistor R10 can pull the anode of the light-emitting part of the optocoupler U1 to a high level when the controller 312 does not output a control signal. One end of the eleventh resistor R11 is adapted to input the first preset power supply VDD, and the other end of the eleventh resistor R11 is connected to one end of the light-receiving part of the optocoupler U1. One end of the twelfth resistor R12 is connected to the other end of the light-receiving part of the optocoupler U1, and the other end of the twelfth resistor R12 is grounded. In this way, when the light-emitting part of the optocoupler U1 is turned off, the twelfth resistor R12 can pull the control terminal of the first switch S1 device Q1 to a low level.

[0058] The control module 31 also includes a voltage conversion submodule 314. The input terminal of the voltage conversion submodule 314 is connected to the output terminal of the first power supply unit 20. The voltage conversion submodule 314 is configured to perform voltage conversion on the output voltage of the first power supply unit 20 to generate a second preset power supply VCC (5V) to power the light-emitting part of the optocoupler U1 and the controller 312.

[0059] In some embodiments, such as Figure 4 As shown, the second power supply unit 30 also includes a power generation module 34, which is connected to the light-receiving part of the optocoupler U1. The power generation module 34 includes an auxiliary winding N3, which is disposed on the primary side of the transformer T. The power generation module 34 is configured to generate a first preset power supply VDD based on the electrical energy coupled to the auxiliary winding N3.

[0060] It is understandable that, since the power generation module 34 is used to generate the first preset power supply VDD, and the light-receiving part of the optocoupler U1 is on the high-voltage side, the auxiliary winding N3 needs to be set on the primary side, that is, on the high-voltage side. When electrical energy is coupled from the primary winding N1 to the secondary winding N2, the electrical energy will also be coupled to the auxiliary winding N3. The power generation module 34 generates the first preset power supply VDD based on the electrical energy coupled to the auxiliary winding N3.

[0061] Optionally, the power generation module 34 also includes a fourth diode D4 and a fifth capacitor C5. The anode of the fourth diode D4 is connected to one end of the auxiliary winding N3, the cathode of the fourth diode D4 is connected to one end of the fifth capacitor C5, and is adapted to output a first preset power supply VDD. The other end of the fifth capacitor C5 is connected to the other end of the auxiliary winding N3 and is grounded.

[0062] In the above embodiments, the power supply for the optocoupler and controller is generated by the power generation module and the voltage conversion submodule, eliminating the need for an additional power supply and simplifying the circuit structure of the second power supply unit.

[0063] In some embodiments, such as Figure 5 As shown, the first controllable switch unit 40 includes a first switch S1, a second switch S2, and a third switch S3. One end of the first switch S1 is adapted to be connected to the positive terminal of the power battery 300, and the other end of the first switch S1 is connected to the voltage conversion unit 10. One end of the second switch S2 is adapted to be connected to the negative terminal of the power battery 300, and the other end of the second switch S2 is connected to the voltage conversion unit 10. One end of the third switch S3 is adapted to be connected to the positive terminal of the power battery 300, and the other end of the third switch S3 is connected to the second power supply unit 30.

[0064] Specifically, when the vehicle is powered on, the first switch S1 and the second switch S2 are in the on state, and the third switch S3 is in the off state. The power battery 300 outputs high-voltage electricity to the high-voltage device 400 and the voltage conversion unit 10. When the vehicle is powered off, the vehicle controller sends a control command to the first controllable switch unit 40, the first switch S1 and the second switch S2 turn off, the third switch S3 turns on, the power battery 300 stops outputting high-voltage electricity to the high-voltage device 400 and the voltage conversion unit 10, and outputs high-voltage electricity to the second power supply unit 30. It should be noted that the first switch S1, the second switch S2, and the third switch S3 can each be a relay.

[0065] Furthermore, the low-voltage power supply circuit 100 also includes a protection unit 60, which is disposed between the third switch S3 and the second power supply unit 30. When a short-circuit fault occurs in the second power supply unit 30, the protection unit 60 can disconnect the connection between the third switch S3 and the second power supply unit 30 to prevent the second power supply unit 30 from continuing to be short-circuited. The protection unit 60 may include a fuse F1. When a short-circuit fault occurs in the second power supply unit 30, the current will increase, and the fuse F1 will blow when the current increases to a preset current threshold.

[0066] In one alternative implementation, if the voltage conversion unit 10 malfunctions when the vehicle is powered on, the vehicle controller can also control the third switch S3 to turn on, so that the second power supply unit 30 and the first power supply unit 20 can supply low voltage together, thereby extending the power supply time of the first power supply unit 20 so that the vehicle can be driven to the repair shop for repair.

[0067] In some embodiments, the first power supply unit 20 includes a supercapacitor.

[0068] It is understandable that, since the low-voltage device 200 can be powered independently by the second power supply unit 30, and the second power supply unit 30 can charge the first power supply unit 20, the first power supply unit 20 can be a supercapacitor. Furthermore, when the output module 32 charges the supercapacitor, the controller 312 can adjust the charging current of the supercapacitor by adjusting the duty cycle of the PWM signal.

[0069] In summary, the low-voltage power supply circuit according to the embodiment of this utility model includes a voltage conversion unit, a first power supply unit, a second power supply unit, and a first controllable switch unit. The first power supply unit is connected to the voltage conversion unit and is adapted to connect to low-voltage devices. The voltage conversion unit is configured to generate low-voltage electricity based on the high-voltage electricity output from the power battery. The first power supply unit is configured to store the low-voltage electricity and use it to power the low-voltage devices. The second power supply unit is adapted to connect to the low-voltage devices and is configured to generate low-voltage electricity based on the high-voltage electricity to power the low-voltage devices. The first controllable switch unit is connected to both the voltage conversion unit and the second power supply unit and is adapted to connect to the power battery. The first controllable switch unit is configured to stop supplying high-voltage electricity to the voltage conversion unit and supply high-voltage electricity to the second power supply unit upon receiving a control command from the vehicle controller. The vehicle controller generates the control command when it determines that the vehicle has entered a sleep state. Therefore, the second power supply unit can supply power to the low-voltage devices together with the first power supply unit after the vehicle enters the sleep state, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the power of the low-voltage battery. In this way, the first power supply unit can meet the power supply needs of the vehicle when it is powered on again.

[0070] Corresponding to the above embodiments, this utility model also proposes a vehicle. For example... Figure 1 As shown, the vehicle includes a low-voltage power supply circuit 100 according to any of the foregoing embodiments.

[0071] According to the vehicle of this utility model embodiment, by adopting the above-mentioned low-voltage power supply circuit, the second power supply unit can supply power to the low-voltage devices together with the first power supply unit after the vehicle enters the sleep state, reducing the power loss of the first power supply unit and thus solving the problem of maintaining the power of the low-voltage battery. In this way, the first power supply unit can meet the power supply needs of the vehicle when it is powered on again.

[0072] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0073] Furthermore, the terms "first," "second," etc., used in the embodiments of this utility model are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this utility model can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this utility model, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0074] In this utility model, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific implementation.

[0075] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A low-voltage power supply circuit for a vehicle, characterized in that, include: A voltage conversion unit and a first power supply unit are provided. The first power supply unit is connected to the voltage conversion unit and is adapted to connect to low-voltage devices. The voltage conversion unit is configured to generate low-voltage electricity based on the high-voltage electricity output from the power battery. The first power supply unit is configured to store the low-voltage electricity and use the low-voltage electricity to power the low-voltage devices. A second power supply unit is adapted to connect to the low-voltage device, and the second power supply unit is configured to generate the low-voltage electricity based on the high-voltage electricity to power the low-voltage device. A first controllable switch unit is connected to the voltage conversion unit and the second power supply unit respectively, and is adapted to connect to the power battery. The first controllable switch unit is configured to stop supplying the high voltage to the voltage conversion unit and supply the high voltage to the second power supply unit when receiving a control command sent by the vehicle controller. The vehicle controller generates the control command when it determines that the vehicle has entered a sleep state.

2. The low-voltage power supply circuit according to claim 1, characterized in that, The second power supply unit includes: A transformer, wherein one end of the primary winding of the transformer is connected to the first controllable switching unit; A first switching device, wherein a first terminal of the first switching device is connected to the other end of the primary winding, and a second terminal of the first switching device is grounded; A control module is connected to the control terminal of the first switching device and is adapted to be connected to the vehicle controller. The control module is configured to control the switching of the first switching device upon receiving a start command from the vehicle controller, so as to couple the electrical energy provided by the high voltage from the primary winding to the secondary winding through the transformer. The vehicle controller sends the start command to the control module after sending the control command to the first controllable switching unit, and enters a sleep state after sending the start command. An output module, connected to the secondary winding and adapted to connect to the low-voltage device, is configured to output the low-voltage electricity based on the electricity coupled to the secondary winding.

3. The low-voltage power supply circuit according to claim 2, characterized in that, It also includes a second controllable switch unit, one end of which is connected to the first power supply unit, and the other end of which is connected to the output module and adapted to connect to the low-voltage device. The control terminal of the second controllable switch unit is connected to the control module. The control module is further configured to control the second controllable switch unit according to the output voltage of the first power supply unit, so that the first power supply unit stops supplying power to the low-voltage device, or charges the first power supply unit according to the electrical energy output by the output module.

4. The low-voltage power supply circuit according to claim 3, characterized in that, The second power supply unit further includes a sampling module. The input terminal of the sampling module is connected to the first power supply unit, and the output terminal of the sampling module is connected to the control module. The sampling module is configured to sample the output voltage of the first power supply unit to obtain first voltage information and provide the first voltage information to the control module. The control module is further configured to control the second controllable switch unit to disconnect when the first voltage information is greater than a preset voltage threshold, so that the first power supply unit stops supplying power to the low-voltage device, and to control the second controllable switch unit to turn on when the first voltage information is less than or equal to the preset voltage threshold, so that the output module charges the first power supply unit.

5. The low-voltage power supply circuit according to claim 2, characterized in that, The control module includes: A sampling submodule is connected to the output module and is configured to sample the output voltage of the output module to obtain second voltage information. A controller, connected to the sampling submodule and adapted to be connected to the vehicle controller, is configured to generate a control signal for the first switching device based on the second voltage information upon receiving the start command, so as to maintain the output voltage of the output module at a preset voltage value; An isolation transmission submodule is connected to the control terminals of the controller and the first switching device, respectively, and is configured to transmit the control signal to the control terminal of the first switching device in an isolated manner.

6. The low-voltage power supply circuit according to claim 5, characterized in that, The isolated transmission submodule includes an optocoupler. The anode of the light-emitting part of the optocoupler is connected to the controller, the cathode of the light-emitting part of the optocoupler is grounded, one end of the light-receiving part of the optocoupler is adapted to input a first preset power supply, and the other end of the light-receiving part of the optocoupler is connected to the control terminal of the first switching device.

7. The low-voltage power supply circuit according to claim 6, characterized in that, The second power supply unit further includes a power generation module, which is connected to the light-receiving part of the optocoupler. The power generation module includes an auxiliary winding, which is disposed on the primary side of the transformer. The power generation module is configured to generate the first preset power supply based on the electrical energy coupled to the auxiliary winding.

8. The low-voltage power supply circuit according to any one of claims 1-7, characterized in that, The first controllable switch unit includes: A first switch, one end of which is adapted to be connected to the positive terminal of the power battery, and the other end of which is connected to the voltage conversion unit; A second switch, one end of which is adapted to be connected to the negative terminal of the power battery, and the other end of which is connected to the voltage conversion unit; A third switch, one end of which is adapted to be connected to the positive terminal of the power battery, and the other end of which is connected to the second power supply unit.

9. The low-voltage power supply circuit according to any one of claims 1-7, characterized in that, The first power supply unit includes a supercapacitor.

10. A vehicle, characterized in that, Includes a low-voltage power supply circuit according to any one of claims 1-9.

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