Vehicle emergency charging system, control method and vehicle

Abstract

The present application relates to a vehicle emergency charging system, a control method and a vehicle. The vehicle emergency charging system includes: an AC charging module connected to an AC charging interface and a power battery, a DC conversion module connected to the AC charging module and a low-voltage battery, a low-voltage battery for low-voltage power supply to the whole vehicle and an auxiliary power supply circuit. When the low-voltage battery is fed, power is taken from the AC charging interface through the auxiliary power supply circuit, and the AC power is converted into low-voltage power through the auxiliary power supply circuit to supply power to a control unit of the AC charging module and a control unit of the DC conversion module. The original charging system topology is optimized and integrated, and the auxiliary power supply circuit is separated from the normal power supply circuit. The auxiliary power supply circuit is only used to power the low-voltage load of the whole vehicle, which can reduce the power of the auxiliary power supply circuit, reduce the size and cost of the device, and control the power supply of the auxiliary power supply circuit to be stable, thereby ensuring the power supply safety of the charging system.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular, to a vehicle emergency charging system, a control method and a vehicle. Background Art

[0002] The low-voltage battery of an automobile, also called a "small battery", is a device that converts chemical energy into electrical energy and is a reversible DC power supply. In electric vehicles, the low-voltage battery is connected in parallel with the DC to supply power to the electrical equipment of the entire vehicle to start the vehicle at the beginning of the vehicle. When the vehicle is stored for a long time without timely recharging the battery, or when the battery is fed due to long-term driving, the vehicle can usually only be moved to the side of the charging pile and the battery needs to be charged through other tools, such as charging the battery of the feeding vehicle from the battery of another car, or charging the battery of the feeding vehicle through a mobile power bank; then start the vehicle and perform AC and DC charging. Existing solutions require thicker wiring harnesses for jumpering, and the jumpering operation is complicated and there are safety hazards. Customers may make mistakes and cause damage to the vehicle or even personal injury accidents.

[0003] When the vehicle's power battery and storage battery are powered, the controllers of all high-voltage modules of the vehicle cannot be powered and cannot start because the control module cannot be powered. As a result, the power battery cannot be charged and the vehicle cannot be started, affecting the user experience. Summary of the invention

[0004] The purpose of this application is to provide a vehicle emergency charging system, a control method and a vehicle.

[0005] In order to achieve the above objectives, in a first aspect, the present application provides a vehicle emergency charging system, comprising:

[0006] an AC charging module, wherein a first end of the AC charging module is connected to an external AC charging interface, and a second end of the AC charging module is connected to a power battery;

[0007] A DC conversion module, a first end of the DC conversion module is connected to a second end of the AC charging module;

[0008] A low-voltage battery, wherein a first end of the low-voltage battery is connected to a second end of the DC converter, and a second end of the battery is connected to a control unit of the AC charging module and a control unit of the DC conversion module;

[0009] An auxiliary power supply circuit, wherein the first end of the auxiliary power supply circuit is connected to the AC charging interface, and the second end of the auxiliary power supply circuit is connected to the control unit of the AC charging module and the control unit of the DC conversion module; when the low-voltage battery is in a feeding state, the auxiliary power supply circuit converts the AC power into target low-voltage power to supply power to the control unit of the AC charging module and the control unit of the DC conversion module.

[0010] The vehicle emergency charging system of the present application, when the low-voltage battery is feeding power, draws power from the AC charging interface by setting an auxiliary power supply circuit, and converts the AC power output from the AC charging interface into low-voltage power through the auxiliary power supply circuit, which can be used to power the control unit of the AC charging module and the control unit of the DC conversion module, so that when the controller of the vehicle's high-voltage module cannot be started by feeding power, it can be powered by the auxiliary power supply circuit to complete the control function of the high-voltage module and assist the vehicle in powering on and starting.

[0011] Furthermore, the auxiliary power supply circuit includes: a rectifier bridge unit, an oscillation circuit and an auxiliary transformer;

[0012] The input end of the rectifier bridge unit is connected to the AC charging interface, and the output end of the rectifier bridge is connected to an auxiliary transformer through an oscillation circuit, and the auxiliary transformer is used to output target low-voltage electricity.

[0013] Furthermore, the control unit of the AC charging module and the control unit of the DC conversion module are connected to the battery management module of the power battery via a communication bus.

[0014] A second aspect of the present application provides a control method for a vehicle emergency charging system, the vehicle emergency charging system comprising:

[0015] an AC charging module, wherein a first end of the AC charging module is connected to an external AC charging interface, and a second end of the AC charging module is connected to a power battery;

[0016] A DC conversion module, a first end of the DC conversion module is connected to a second end of the AC charging module;

[0017] A low-voltage battery, wherein a first end of the low-voltage battery is connected to a second end of the DC converter, and a second end of the battery is connected to a control unit of the AC charging module and a control unit of the DC conversion module;

[0018] An auxiliary power supply circuit, wherein a first end of the auxiliary power supply circuit is connected to the AC charging interface, and a second end of the auxiliary power supply circuit is connected to a control unit of the AC charging module and a control unit of the DC conversion module;

[0019] The method comprises:

[0020] When the low-voltage battery is in a state of being fed,

[0021] Upon receiving a charging instruction, the auxiliary power circuit is awakened;

[0022] The external power supply device outputs AC power to the auxiliary power supply circuit, and the auxiliary power supply circuit converts the AC power into target low-voltage power to supply power to a control unit of the AC charging module and a control unit of the DC conversion module.

[0023] The vehicle emergency charging system control method of the present application controls the auxiliary power supply circuit to draw power from the AC charging interface when the low-voltage battery is feeding power, and converts the AC power into the target low-voltage power to supply power to the control unit of the AC charging module and the control unit of the DC conversion module, so that when the controller of the vehicle's high-voltage module cannot be started by feeding power, it can be powered by the auxiliary power supply circuit to complete the control function of the high-voltage module and assist the vehicle in powering on and starting.

[0024] Furthermore, the control unit of the AC charging module and the control unit of the DC conversion module are connected to the battery management module of the power battery via a communication bus;

[0025] The method further comprises: after the control unit of the DC conversion module is powered on, acquiring the battery status of the low-voltage battery;

[0026] If the battery state of the low-voltage battery is normal, the DC conversion module enters the emergency charging mode and sends an emergency charging entry signal to the communication bus.

[0027] Further, the method further comprises: the control unit of the AC charging module shielding a voltage sampling protection function of the AC charging module according to the emergency charging entry signal;

[0028] The control unit of the AC charging module controls and identifies a first load parameter of a bus output passive load, and starts a transformer voltage regulating circuit of the AC charging module according to the first load parameter to convert the voltage of the AC power output by the AC charging interface into a first output voltage matching the first load parameter.

[0029] Furthermore, the method further includes: the DC conversion module converts the first output voltage into a battery charging voltage to charge the low-voltage battery.

[0030] Furthermore, the method further includes: when the DC conversion module detects that the output current reaches a preset value, a high-voltage pickup signal is sent to the communication bus to request the positive and negative bus contactors of the power battery to be attracted.

[0031] Furthermore, the method further comprises: the battery management system of the power battery reports the voltage parameter of the power battery to the control unit of the AC charging module according to the high-voltage pickup signal;

[0032] The AC charging module adjusts the output voltage based on the voltage parameter of the power battery, and adjusts the output voltage to within a preset voltage difference range of the voltage parameter of the power battery;

[0033] The battery management system of the power battery controls the positive and negative contactors to be attracted to charge the power battery.

[0034] Furthermore, the method further includes: when the power battery is being charged, exiting the auxiliary power circuit power supply process.

[0035] A third aspect of the present application provides a vehicle, comprising the vehicle emergency charging system described in the first aspect.

[0036] The technical solution of the present application provides a vehicle emergency charging system, a control method and a vehicle. By setting up an auxiliary power supply circuit, when the low-voltage battery is fed, power can be directly taken from the AC charging interface and converted into the target low-voltage power to supply power to the control unit of the AC charging module and the control unit of the DC conversion module. The original charging system topology is optimized and integrated to realize the emergency charging function of the control module of the high-voltage device, which greatly solves the problem of feeding the low-voltage battery and improves the user experience.

[0037] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0039] Figure 1 The figure is a schematic block diagram of the structure of a vehicle emergency charging system according to an embodiment.

[0040] Figure 2 The figure is a schematic diagram of the structure of an auxiliary power supply circuit of a vehicle emergency charging system according to an embodiment.

[0041] Figure 3 The figure is a flow chart of a control method of a vehicle emergency charging system according to an embodiment.

[0042] Figure 4The present invention is a schematic diagram of an emergency switch circuit of a vehicle emergency charging system according to an embodiment.

[0043] Figure 5 The figure is a schematic block diagram of the structure of another vehicle emergency charging system according to an embodiment.

[0044] Figure 6 The figure is a schematic diagram of a working mode of a vehicle emergency charging system according to an embodiment.

[0045] Figure 7 It is a schematic diagram of the structure of a vehicle according to an embodiment.

[0046] Reference numerals:

[0047] 10. AC charging module; 20. DC conversion module; 30. Low-voltage battery;

[0048] 40. Auxiliary power supply circuit; 41. Rectifier bridge unit; 42. Oscillation circuit; 43. Auxiliary transformer;

[0049] R L : Pull-down resistor; S1: pull-down switch; R1, first resistor; R2, second resistor. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] In order to illustrate the technical solution of this application, Figure 1-Figure 7 The following description will be given by way of specific examples.

[0052] The vehicle emergency charging system of the present application is connected to an external AC power supply device and a power battery of the vehicle, and is used to power a control unit of an AC charging module and a control unit of a DC conversion module when the battery is at low voltage.

[0053] like Figure 1 As shown, the vehicle emergency charging system includes: an AC charging module 10, a DC conversion module 20, a low-voltage battery 30 and an auxiliary power supply circuit 40.

[0054] A first end of the AC charging module 10 is connected to an external AC charging interface, and a second end of the AC charging module 10 is connected to a power battery; a first end of the DC conversion module 20 is connected to a second end of the AC charging module 10; a second end of the DC converter is connected to a first end of a low-voltage battery 30, and a second end of the battery is connected to a control unit of the AC charging module 10 and a control unit of the DC conversion module 20; a first end of the auxiliary power supply circuit 40 is connected to the AC charging interface, and a second end of the auxiliary power supply circuit 40 is connected to a control unit of the AC charging module 10 and a control unit of the DC conversion module 20.

[0055] When the low-voltage battery 30 is in a feeding state, the auxiliary power circuit 40 converts the AC power into target low-voltage power to supply power to the control unit of the AC charging module 10 and the control unit of the DC conversion module 20 .

[0056] Specifically, the AC charging module 10 can be an on-board AC charger for an electric vehicle, i.e., an OBC, which is a high-voltage device used to perform AC charging for an electric vehicle. The AC charging module 10 can include a rectifier and filter unit and a transformer. The rectifier and filter unit and transformer of the AC charging module 10 are high-voltage components used to convert 220V or 380V AC power into high-voltage DC power that matches the power battery to charge the power battery. The control unit of the AC charging module 10 is a control element, which is connected to the AC charging module 10 and is powered by a low-voltage battery 30, generally with a 12V supply voltage. The first end of the AC charging module 10 can be an input end, which is connected to the AC charging interface and draws power from an external AC charging pile. The second end of the AC charging module 10 can be an output end, which outputs DC power after rectification and transformation by the AC charging module 10.

[0057] The DC conversion module 20 may be a DC / DC module of an electric vehicle, which is a high-voltage device for converting high-voltage DC power into low-voltage DC power for charging the low-voltage battery 30. The DC / DC module may include a DC filter unit and a transformer unit. The DC filter unit of the DC conversion module 20, the transformer unit is a high-voltage component, and is used to convert the high-voltage DC power output by the AC charging module 10 into low-voltage DC power matching the low-voltage battery 30 for charging the low-voltage battery 30. The control unit of the DC conversion module 20 is a control element, which is connected to the DC conversion module 20 and powered by the low-voltage battery 30, generally with a 12V supply voltage. The first end of the DC conversion module 20 may be an input end, which is connected to the output end of the AC charging module 10 and takes power from the output end of the AC charging module 10. The second end of the DC conversion module 20 may be an output end, which outputs the low-voltage DC power converted by the DC conversion module 20. It can be understood that the input and output ends of the bidirectional DC / DC module can be adaptively changed in different working conditions.

[0058] The low-voltage battery 30 is also called a "small battery" and is a reversible DC power source. It is used to supply power to the electrical equipment of the vehicle to start the vehicle at the beginning of the vehicle startup. For example, it is used to supply power to the control unit of the AC charging module 10 and the control unit of the DC conversion module 20.

[0059] The auxiliary power supply circuit 40 is connected to the AC charging interface side. When the low-voltage battery 30 feeds power, the auxiliary power supply circuit 40 directly draws power from the AC charging pile and converts the AC power into target low-voltage power to supply power to the control unit of the AC charging module 10 and the control unit of the DC conversion module 20. The target low-voltage power refers to low-voltage power that matches the power supply voltage of the control unit of the AC charging module 10 and the control unit of the DC conversion module 20. The target low-voltage power can also be used to supply power to the low-voltage power load of the whole vehicle.

[0060] Furthermore, if Figure 2 As shown, the auxiliary power supply circuit 40 includes: a rectifier bridge unit 41, an oscillating circuit 42 and an auxiliary transformer 43. The input end of the rectifier bridge unit 41 is connected to the AC charging interface, and the output end of the rectifier bridge is connected to the auxiliary transformer 43 through the oscillating circuit 42, and the auxiliary transformer 43 is used to output the target low voltage electricity.

[0061] Specifically, the AC power of the charging pile is input from the AC charging interface, passes through the rectifier bridge unit 41, and generates an oscillating current through the oscillation circuit, and is transformed into a 12V low-voltage power through the auxiliary transformer 43, which is rectified and filtered before output to supply the low-voltage load of the vehicle. The auxiliary power supply circuit 40 has a simple structure and is easy to implement.

[0062] Furthermore, the control unit of the AC charging module 10 and the control unit of the DC conversion module 20 are connected to the battery management module of the power battery via a communication bus. The communication bus may be a CAN bus, and the control unit of the AC charging module 10 and the control unit of the DC conversion module 20 and the battery management module of the power battery are all connected to the communication bus, and information communication between the control modules can be realized through the communication bus.

[0063] The vehicle emergency charging system of the present application, by setting up an auxiliary power supply circuit 40, can directly draw power from the AC charging interface and convert it into target low-voltage power when the low-voltage battery 30 is feeding power, so as to supply power to the control unit of the AC charging module 10 and the control unit of the DC conversion module 20, optimize and integrate the original charging system topology, and separate the auxiliary power supply circuit 40 from the normal power supply circuit. The auxiliary power supply circuit 40 is only used to supply power to the low-voltage load of the whole vehicle, which can reduce the power of the auxiliary power supply circuit 40, reduce the size and cost of the device, and control the auxiliary power supply circuit 40 to ensure stable power supply without overcurrent, thereby ensuring the power supply safety of the charging system.

[0064] The present application also provides a control method for a vehicle emergency charging system. To illustrate the technical solution of the present application, Figure 1-Figure 6 The following description will be given by way of specific examples.

[0065] Under normal circumstances, the low-voltage battery 30 is used to supply power to the control module of the vehicle's high-voltage module. When the low-voltage battery 30 is discharged, the low-voltage battery 30 cannot supply power to the control module, and the power battery cannot charge the low-voltage battery 30. At this time, the controllers of all high-voltage modules of the vehicle cannot be powered and started. Even if the vehicle is connected to an external charging pile, the controller of the high-voltage module cannot start handshaking with the external charging pile, and the power battery cannot be charged. The vehicle falls into an endless loop of being unable to charge and start.

[0066] The control method of the vehicle emergency charging system provided in the present application is applied to the vehicle emergency charging system, which includes: an AC charging module 10, a DC conversion module 20, a low-voltage battery 30 and an auxiliary power supply circuit 40.

[0067] A first end of the AC charging module 10 is connected to an external AC charging interface, and a second end of the AC charging module 10 is connected to a power battery; a first end of the DC conversion module 20 is connected to a second end of the AC charging module 10; a second end of the DC converter is connected to a first end of a low-voltage battery 30, and a second end of the battery is connected to a control unit of the AC charging module 10 and a control unit of the DC conversion module 20; a first end of the auxiliary power supply circuit 40 is connected to the AC charging interface, and a second end of the auxiliary power supply circuit 40 is connected to a control unit of the AC charging module 10 and a control unit of the DC conversion module 20.

[0068] like Figure 3 As shown, the control method of the vehicle emergency charging system includes:

[0069] When the low-voltage battery 30 is in a state of being fed, the auxiliary power supply circuit 40 wakes up upon receiving a charging instruction.

[0070] The external power supply device outputs AC power to the auxiliary power circuit 40 , and the auxiliary power circuit 40 converts the AC power into target low-voltage power to supply power to the control unit of the AC charging module 10 and the control unit of the DC conversion module 20 .

[0071] Specifically, when the low-voltage battery 30 is in a feeding state, the auxiliary power circuit 40 is awakened when a charging instruction is received. The charging instruction refers to an instruction issued after the vehicle is connected to the charging pile and powered on. In some charging piles, the charging pile is connected to the vehicle through a charging gun, and a card is required to swipe the charging pile to connect to the vehicle for power. In some embodiments, the charging pile is connected to the vehicle and the card is swiped to power on. The charging pile issues a charging instruction to the vehicle, and the vehicle wakes up the auxiliary power circuit 40 when receiving the charging instruction.

[0072] Specifically, waking up the auxiliary power supply circuit 40 can be through the emergency charging switch of the auxiliary power supply circuit 40, wherein the emergency charging switch of the auxiliary power supply circuit 40 can be a signal-triggered soft switch configured by a hardware circuit, or it can be a physical switch with a physical button set to wake up through mechanical action.

[0073] In one embodiment, the emergency switch circuit is as follows Figure 4 As shown, the emergency switch circuit includes a pull-down resistor R L , pull down switch S1, the voltage divider resistors first resistor R1 and second resistor R2. L The first end is connected to the charging socket, and the pull-down resistor R L The second end of the first resistor R1 is connected to the first end of the pull-down switch S1, and the second end of the pull-down switch S1 is connected to the vehicle body ground. L The first end of the pull-down resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected in series with the third end of the pull-down switch S1, and the low-voltage battery 30 is connected between the first resistor R1 and the second resistor R2 through a transistor switch. L The first end of the pull-down switch S1 forms a voltage input point, and the third end of the pull-down switch S1 forms a signal output point. Its working principle is: when the battery voltage is lower than the design value, the user inserts the gun and swipes the card, there is voltage on the CP in the charging gun, and there is a level of the charging pile CP connected to the vehicle through the charging gun at the voltage input point, which turns on the pull-down switch S1, and sends a level signal from the signal output point of the third end of the pull-down switch S1 to wake up the auxiliary power circuit 40. Waking up the auxiliary power circuit 40 can also be done by the user manually pressing a physical button, and the button action generates a level to wake up the auxiliary power circuit 40.

[0074] After being awakened, the auxiliary power circuit 40 completes handshake interaction with the external power supply device through the AC charging interface. The external power supply device outputs AC power, and the auxiliary power circuit 40 takes power from the AC charging interface and converts the AC power into target low-voltage power. The target low-voltage power refers to low-voltage power that matches the power supply voltage of the control unit of the AC charging module 10 and the control unit of the DC conversion module 20. The target low-voltage power is used to supply power to the control unit of the AC charging module 10 and the control unit of the DC conversion module 20.

[0075] The control method of a vehicle emergency charging system of the present application aims to control the auxiliary power supply circuit 40, so that when the low-voltage battery 30 is feeding, the auxiliary power supply circuit 40 can take power from the AC charging interface, convert the AC power into the target low-voltage power, and realize the power supply of the control unit of the AC charging module 10 and the control unit of the DC conversion module 20, so that when the controller of the vehicle high-voltage module cannot be started by feeding, it can be powered by the auxiliary power supply circuit 40 to complete the control function of the high-voltage module and assist the vehicle in powering on. This process can avoid safety accidents caused by mistakes in user operation.

[0076] In one embodiment, the control unit of the AC charging module 10 and the control unit of the DC conversion module 20 are connected to the battery management module of the power battery through a communication bus, and are both connected to the vehicle controller. The connection relationship diagram of the vehicle control module connected through the communication line is no longer shown. It can be understood that the communication bus can be a CAN bus, and the control unit of the AC charging module 10 and the control unit of the DC conversion module 20 connected through the CAN bus can realize signal communication with the battery management module of the power battery and the vehicle controller.

[0077] The vehicle emergency charging system method also includes: the control unit of the DC conversion module 20 obtains the battery status of the low-voltage battery 30 after being powered; if the battery status of the low-voltage battery 30 is normal, the DC conversion module 20 enters the emergency charging mode and sends an emergency charging entry signal to the communication bus.

[0078] Specifically, the control unit of the DC conversion module 20 starts working after being powered on, and obtains the battery status of the low-voltage battery 30. The battery status of the low-voltage battery 30 includes a normal state and an abnormal state. The normal state means that the low-voltage battery 30 has no faults, and the abnormal state means that the low-voltage battery 30 has faults. The emergency charging mode means that when the low-voltage battery 30 is powered, the control unit of the DC conversion module 20 is powered through the auxiliary power supply circuit 40 to control the power supply process of the DC conversion module 20. If the battery status of the low-voltage battery 30 is normal, and it is determined that the low-voltage battery 30 has no faults, the DC conversion module 20 enters the emergency charging mode and sends an emergency charging entry signal to the communication bus. The emergency charging entry signal instructs the DC conversion module 20 to enter the emergency charging process.

[0079] In this embodiment, after determining the battery status of the low-voltage battery 30, the control module of the DC conversion module 20 controls the DC conversion module 20 to enter the emergency charging mode. The DC conversion module 20 relies on the auxiliary power supply circuit 40 to forcibly enter the emergency charging mode to achieve more charging modes and better adapt to various power feeding conditions of the vehicle.

[0080] Furthermore, the vehicle emergency charging system method further includes: the control unit of the AC charging module 10 shields the voltage sampling protection function of the AC charging module 10 according to the emergency charging entry signal.

[0081] The control unit of the AC charging module 10 controls and identifies the first load parameter of the bus output passive load, and starts the transformer voltage regulating circuit of the AC charging module 10 according to the first load parameter to convert the voltage of the AC power output by the AC charging interface into a first output voltage matching the first load parameter.

[0082] Among them, the voltage sampling protection function means that during the AC charging process, the AC charging module 10 needs to sample the battery voltage of the power battery to prevent the AC charging module 10 from outputting too high a voltage and causing damage to the power battery. If the AC charging module 10 cannot sample the voltage of the power battery, it is assumed that the AC charging module 10 and the power battery are not ready for charging connection, and the AC charging module 10 does not output electricity. The bus output passive load refers to the auxiliary load connected to the DC bus, which can be load-type electronic components such as bus capacitors and passive discharge resistors. The bus output passive load can be all auxiliary loads connected to the DC bus, or it can be part of the auxiliary loads connected to the DC bus. The first load parameter refers to the parameter information of the bus output passive load, including the load size of the bus output passive load.

[0083] In the emergency charging mode, the control unit of the AC charging module 10 shields its voltage sampling protection function, that is, does not sample and confirm the battery voltage of the power battery. In addition, the control unit of the AC charging module 10 controls the identification of the first load parameter of the bus output passive load, starts the transformer voltage regulation circuit of the AC charging module 10, and converts the voltage of the AC power output by the AC charging interface to a first output voltage matching the first load parameter.

[0084] In this embodiment, the voltage sampling protection function of the AC charging module 10 is shielded in the emergency charging mode, so that the AC charging module 10 can output a first output voltage matching the first load parameter according to the first load parameter of the bus output passive load, so that when the AC charging module 10 does not collect the battery voltage of the power battery, it can also output the corresponding voltage by borrowing the first load parameter of the bus output passive load to realize the output of the AC charging module 10.

[0085] Furthermore, the vehicle emergency charging system method further includes: the DC conversion module 20 converts the first output voltage into a battery charging voltage for charging the low-voltage battery 30 .

[0086] Specifically, after the AC charging module 10 outputs the first output voltage, the DC conversion module 20 draws power from the output end of the AC charging module 10, converts the first output voltage into a battery charging voltage, and charges the low-voltage battery 30. In this embodiment, the DC conversion module 20 charges the low-voltage battery 30 by converting the first output voltage of the AC charging module 10 into a battery charging voltage. The electric energy for charging the low-voltage battery 30 is obtained from the DC conversion module 20, rather than being directly provided by the auxiliary power supply circuit 40. The current of the auxiliary power supply circuit 40 does not flow to the battery, which reduces the power of the auxiliary power supply circuit 40 and ensures that the charging of the low-voltage battery 30 is more stable.

[0087] Furthermore, the vehicle emergency charging system method also includes: when the DC conversion module 20 detects that the output current reaches a preset value, it sends a high-voltage contactor pull-in signal to the communication bus to request the positive and negative bus contactors of the power battery to be pulled in.

[0088] Specifically, when the DC conversion module 20 charges the low-voltage battery 30, when the DC conversion module 20 detects that its output current reaches a preset value, it is determined that the DC conversion module 20 has a valid output. The high-voltage contactor pull-in signal refers to an indication signal issued by the DC conversion module 20 after there is a valid output to request the positive and negative bus contactors of the power battery to be pulled in. The high-voltage contactor pull-in signal is sent to the battery management system of the power battery through the communication bus. The positive and negative bus contactors of the power battery are respectively arranged on the positive and negative buses of the DC bus, and are used to control the connection and disconnection between the power battery and the DC positive and negative buses. Generally speaking, the positive and negative bus contactors of the power battery are arranged between the power battery and the AC charging module 10 and the DC conversion module 20, and are used to control the connection and disconnection between the power battery and the AC charging module 10 and the DC conversion module 20.

[0089] In this embodiment, after the DC conversion module 20 detects that it has a valid output, it sends a high-voltage contactor pull-in signal to request the high-voltage contactor pull-in signal of the positive and negative bus contactors of the power battery to be pulled in, thereby ensuring the stability of the battery charging and making the charging process safer.

[0090] Furthermore, the vehicle emergency charging system method further includes: the battery management system of the power battery reports the voltage parameters of the power battery to the control unit of the AC charging module 10 according to the high-voltage contactor pull-in signal;

[0091] The AC charging module 10 adjusts the output voltage based on the voltage parameters of the power battery, and adjusts the output voltage to within a preset voltage difference range of the voltage parameters of the power battery;

[0092] The battery management system of the power battery controls the positive and negative contactors to close and charge the power battery.

[0093] Specifically, after the battery management system of the power battery receives the high-voltage contactor closure signal from the DC conversion module 20 on the communication bus, it reports the voltage parameters of the power battery to the control unit of the AC charging module 10, including the voltage, current, temperature and other electrical parameters of the power battery. The AC charging module 10 adjusts the output voltage according to the voltage parameters of the power battery, and adjusts the output voltage to within the preset voltage difference range (±10V) of the voltage parameters of the power battery, completing the pre-charging process so that the output voltage of the AC charging module 10 matches the voltage of the power battery to prevent damage to the power battery. After the pre-charging is completed, the battery management system of the power battery controls the positive and negative contactors to close, and the AC charging module 10 enters the normal charging process for the power battery, and the DC conversion module 20 also enters the normal charging process for the low-voltage battery 30.

[0094] In this embodiment, the AC charging module 10 can be used to regulate the voltage to control the voltage difference between the two ends of the high-voltage positive and negative contactors within a safe range, thereby realizing pre-charging of the high-voltage circuit and ensuring the charging safety of the power battery. The AC charging module 10 (OBC) is used to realize pre-charging, and there is no need to interrupt the charging process, so that the AC charging is always stable without restarting.

[0095] Furthermore, when the power battery is charged, the auxiliary power circuit 40 exits the power supply process. That is, after the AC charging module 10 enters the normal charging process for the power battery and the DC conversion module 20 also enters the normal charging process for charging the low-voltage battery 30, the auxiliary power circuit 40 exits the power supply process. The control unit of the AC charging module 10 and the control unit of the DC conversion module 20 are both powered by the low-voltage battery 30. And the low-voltage battery 30 supplies power to the low-voltage electrical equipment of the whole vehicle.

[0096] In one embodiment, when the power battery is charged, the auxiliary power circuit 40 enters a sleep mode. The voltage at the low-voltage battery 30 is higher than the voltage at the output end of the auxiliary power circuit 40. The low-voltage battery 30 supplies power to the low-voltage electrical equipment of the vehicle, and the auxiliary power circuit 40 does not work.

[0097] In particular, when both the power battery and the low-voltage battery 30 are powered, the vehicle cannot be started due to the power battery power supply, and at this time the power supply of the low-voltage battery 30 cannot supply power to the control unit of the high-voltage device of the charging system. The high-voltage devices of the charging system cannot be started due to power supply, and the power battery cannot be charged. According to the vehicle emergency charging system and control method of the present application, a vehicle emergency charging system with an auxiliary power supply circuit 40 is added to the original AC charging process circuit. When the low-voltage battery 30 cannot provide effective power supply, the emergency charging switch is used to simulate the handshake between the vehicle and the charging device, so that the charging device starts to supply power to the vehicle. The auxiliary power supply circuit 40 obtains the AC power provided by the charging device and converts it into the target low-voltage power to supply power to the high-voltage devices of the vehicle charging system, such as the control unit of the AC charging module 10 and the DC conversion module 20. Then the AC charging module 10 and the DC conversion module 20 are started to charge, and when the system is stable, it jumps to the normal charging process of the whole vehicle.

[0098] The vehicle emergency charging system of the present application can be combined and integrated according to hardware modules to derive different implementation methods, and can also adjust different power supply points of the auxiliary power supply circuit 40 and DC / DC to derive different implementation solutions.

[0099] In one embodiment, Figure 5 As shown, the AC charging module 10 includes a PFC unit and a CLLC unit. The first end of the PFC unit is connected to the AC charging interface, the second end of the PFC unit is connected to the first end of the CLLC unit, and the second end of the CLLC unit is connected to the power battery. The first end of the DC conversion module 20 (i.e., DC / DC) is connected to the second end of the PFC unit, and the second end of the DC / DC is connected to the battery. In this embodiment, the power supply point of the DC / DC is at the output side of the PFC. After the control unit of the AC charging module 10 is powered, the PFC is controlled to convert 220V AC power into 320V DC power, the CLLC is turned off, and the DC / DC takes 320V DC power from the output side of the PFC and converts it into DC power of the battery charging voltage to charge the low-voltage battery 30.

[0100] After the AC charging module 10 completes pre-charging and the battery manager of the power battery controls the positive and negative contactors to close, the control unit of the AC charging module 10 controls the CLLC output to charge the power battery.

[0101] Similarly, in one embodiment, in order to reduce its interference with the power grid, an EMI filtering circuit can be added to the front end of the AC input. This part of the circuit can be shared with the OBC AC input part, the volume can be reduced, and the power density is further improved. An EMI module is also provided between the AC charging interface and the AC charging module 10. The first end of the EMI module is connected to the AC charging interface, and the second end of the EMI module is connected to the first end of the AC charging module 10. The power supply point of the auxiliary power supply circuit 40 can be between the EMI module and the AC charging port, that is, the power supply point of the auxiliary power supply circuit 40 can be in front of the EMI module. It can be understood that the above-mentioned AC charging module 10 is the OBC of the vehicle, and the resonant circuit of the OBC includes but is not limited to the CLLC circuit; and, as Figure 6 As shown, the auxiliary power supply circuit 40 includes but is not limited to supplying power to the OBC control unit and the DC / DC control unit, and can also be used to supply power to other low-voltage loads of the vehicle.

[0102] Another aspect of the present application provides a vehicle 200, such as Figure 7 FIG. 2 is a schematic diagram of a vehicle according to an exemplary embodiment of the present application. The vehicle 200 includes the above vehicle emergency charging system 100 .

[0103] Regarding the device in the above embodiment, the connection method of each module and the specific method of performing operations have been described in detail in the embodiment of the device, and will not be elaborated here.

[0104] The preferred embodiments of the present application are described in detail above in conjunction with the accompanying drawings; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

[0105] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

[0106] In addition, the various implementation modes of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

Claims

1. A vehicle emergency charging system, characterized in that: include: an AC charging module, wherein a first end of the AC charging module is connected to an external AC charging interface, and a second end of the AC charging module is connected to a power battery; A DC conversion module, a first end of the DC conversion module is connected to a second end of the AC charging module; A low-voltage battery, wherein a first end of the low-voltage battery is connected to a second end of the DC conversion module, and a second end of the battery is connected to a control unit of the AC charging module and a control unit of the DC conversion module; An auxiliary power supply circuit, wherein a first end of the auxiliary power supply circuit is connected to the AC charging interface, and a second end of the auxiliary power supply circuit is connected to a control unit of the AC charging module and a control unit of the DC conversion module; When the low-voltage battery is in a feeding state, the auxiliary power supply circuit converts the AC power into the target low-voltage power to supply power to the control unit of the AC charging module and the control unit of the DC conversion module; The control unit of the AC charging module and the control unit of the DC conversion module are connected to the battery management module of the power battery via a communication bus; The control unit of the DC conversion module is used to obtain the battery status of the low-voltage battery after power is supplied; the DC conversion module is used to enter the emergency charging mode and send an emergency charging entry signal to the communication bus when the battery status of the low-voltage battery is normal; The control unit of the AC charging module is used to shield the voltage sampling protection function of the AC charging module according to the emergency charging entry signal; the control unit of the AC charging module is used to control the first load parameter for identifying the bus output passive load; The transformer voltage regulating circuit of the AC charging module is started according to the first load parameter to convert the voltage of the AC power output by the AC charging interface into a first output voltage matching the first load parameter.

2. The vehicle emergency charging system according to claim 1, characterized in that: The auxiliary power supply circuit includes: a rectifier bridge unit, an oscillation circuit and an auxiliary transformer; the input end of the rectifier bridge unit is connected to the AC charging interface, the output end of the rectifier bridge is connected to the auxiliary transformer through the oscillation circuit, and the auxiliary transformer is used to output the target low voltage electricity.

3. The vehicle emergency charging system according to claim 1, characterized in that: The control unit of the AC charging module and the control unit of the DC conversion module are connected to the battery management module of the power battery through a communication bus.

4. A control method for a vehicle emergency charging system, characterized in that: The vehicle emergency charging system includes: an AC charging module, wherein a first end of the AC charging module is connected to an external AC charging interface, and a second end of the AC charging module is connected to a power battery; A DC conversion module, a first end of the DC conversion module is connected to a second end of the AC charging module; A low-voltage battery, wherein a first end of the low-voltage battery is connected to a second end of the DC conversion module, and a second end of the battery is connected to a control unit of the AC charging module and a control unit of the DC conversion module; An auxiliary power supply circuit, wherein a first end of the auxiliary power supply circuit is connected to the AC charging interface, and a second end of the auxiliary power supply circuit is connected to a control unit of the AC charging module and a control unit of the DC conversion module; The control unit of the AC charging module and the control unit of the DC conversion module are connected to the battery management module of the power battery via a communication bus; The method comprises: when the low-voltage battery is in a feeding state, upon receiving a charging instruction, waking up the auxiliary power supply circuit; an external power supply device outputs alternating current to the auxiliary power supply circuit, and the auxiliary power supply circuit converts the alternating current into target low-voltage electricity to supply power to a control unit of an alternating current charging module and a control unit of a direct current conversion module; The control unit of the DC conversion module obtains the battery status of the low-voltage battery after being powered; If the battery state of the low-voltage battery is normal, the DC conversion module enters the emergency charging mode and sends an emergency charging entry signal to the communication bus; The control unit of the AC charging module shields the voltage sampling protection function of the AC charging module according to the emergency charging entry signal; the control unit of the AC charging module controls the first load parameter of the bus output passive load to be identified, and starts the transformer voltage regulating circuit of the AC charging module according to the first load parameter to convert the voltage of the AC power output by the AC charging interface into a first output voltage matching the first load parameter.

5. The control method of the vehicle emergency charging system according to claim 4, characterized in that: The method further includes: the DC conversion module converts the first output voltage into a battery charging voltage to charge the low-voltage battery.

6. The control method of the vehicle emergency charging system according to claim 5, characterized in that: The method further comprises: When the DC conversion module detects that the output current reaches a preset value, it sends a high-voltage pickup signal to the communication bus to request the positive and negative bus contactors of the power battery to be attracted.

7. The control method of the vehicle emergency charging system according to claim 6, characterized in that: The method further includes: the battery management system of the power battery reports the voltage parameter of the power battery to the control unit of the AC charging module according to the high-voltage pickup signal; the AC charging module adjusts the output voltage based on the voltage parameter of the power battery, and adjusts the output voltage to within a preset voltage difference range of the voltage parameter of the power battery; The battery management system of the power battery controls the positive and negative bus contactors to be attracted to charge the power battery.

8. The control method of the vehicle emergency charging system according to claim 7, characterized in that: The method further comprises: When the power battery is being charged, the auxiliary power circuit power supply process is exited.

9. A vehicle, characterized in that: It comprises a power battery and a vehicle emergency charging system according to any one of claims 1-3.

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