Electric vehicle DC charging system, electric vehicle and DC charging method

Abstract

This application relates to the technical field of DC charging for electric vehicles, and provides a DC charging system for electric vehicles, an electric vehicle, and a DC charging method. The DC charging system for electric vehicles includes: a vehicle control module; a first end of a first switch switching module is electrically connected to a communication port of an adapter, and a third end of a second switch switching control module is electrically connected to an on-vehicle OBC; a resistance detection module is electrically connected to the adapter to detect the resistance of the adapter; a first end of the second switch switching module is electrically connected to a power output end of the adapter, and a second end of the second switch switching module is electrically connected to an original vehicle battery pack; a first voltage detection module is electrically connected to the first end of the second switch switching module, and the first voltage detection module is electrically connected to the vehicle control module. According to the DC charging system for electric vehicles in the embodiments of this application, automatic detection of the adapter is achieved, and the original vehicle battery pack can be directly charged with low-voltage DC using an AC charging socket without using a DC / DC module.

Description

Technical Field

[0001] This application relates to the technical field of DC charging for electric vehicles, and particularly to a DC charging system for electric vehicles, an electric vehicle, and a DC charging method. Background Art

[0002] In order to meet the needs of different consumers for electric vehicles, automobile manufacturers have successively launched models with different mileage and prices. Some models only have an AC charging socket and cannot directly use DC charging equipment for charging.

[0003] In order to enable vehicles with only AC charging sockets to also have DC charging capabilities, a solution has emerged that uses an adapter to connect to the AC charging socket, allowing the DC charging equipment to charge the vehicle through the adapter. However, in the vehicle charging systems of related technologies, the voltage output by the DC charging equipment must be regulated by a DC / DC module, the solution is relatively complex, and it is difficult to achieve automatic detection of the adapter. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in related technologies. For this purpose, this application proposes a DC charging system for electric vehicles, which realizes automatic detection of the adapter, and based on the detection result of the adapter, controls the vehicle to switch from AC charging to DC charging, and in some cases, can directly perform low-voltage DC charging on the original vehicle battery pack without using a DC / DC module, and the solution is simpler.

[0005] This application also proposes an electric vehicle.

[0006] This application also proposes a DC charging method for electric vehicles.

[0007] The DC charging system for electric vehicles according to an embodiment of this application is suitable for connection with an adapter, and the adapter is suitable for connection with a DC charging device. The DC charging system for electric vehicles includes:

[0008] A vehicle control module;

[0009] A first switch switching module, the first end of the first switch switching module is electrically connected to the communication port of the adapter, the second end of the first switch switching module is electrically connected to the vehicle control module, and the third end of the second switch switching control module is electrically connected to the on-vehicle OBC;

[0010] A resistance detection module, electrically connected to the vehicle control module, and the resistance detection module is electrically connected to the adapter to detect the resistance of the adapter;

[0011] A second switch switching module, a first end of the second switch switching module is electrically connected to a power output end of the adapter, a second end of the second switch switching module is electrically connected to the original vehicle battery pack, and a third end of the second switch switching module is electrically connected to the vehicle control module;

[0012] A voltage conversion module is electrically connected between a fourth end of the second switch switching module and the original vehicle battery pack;

[0013] A first voltage detection module is electrically connected to the first end of the second switch switching module, the first voltage detection module is electrically connected to the vehicle control module, and the first voltage detection module is adapted to detect the voltage magnitude delivered by the DC charging device to the second switch switching module via the adapter;

[0014] A boost module is electrically connected to the vehicle control module, the boost module is electrically connected to the DC charging device, and the boost module is adapted to boost the initial voltage of the vehicle to a preset voltage and then deliver it to the DC charging device.

[0015] According to the electric vehicle DC charging system of the present application embodiment, when the adapter is connected to the vehicle charging socket, the resistance detection module will detect the resistance of the adapter and transmit the detection result to the vehicle control module, so that the vehicle control module can determine whether the device currently connected to the vehicle charging socket is the adapter. When it is determined that the adapter is connected to the vehicle charging socket, the vehicle control module controls the first end and the second end of the first switch switching module to be connected, so that the communication port of the adapter is connected to the vehicle control module, and the vehicle control module can interact with the DC charging device through the communication port of the adapter.

[0016] The vehicle control module obtains the charging voltage of the original vehicle battery pack and the output voltage range of the DC charging device, and compares the charging voltage of the original vehicle battery pack with the output voltage range of the DC charging device. When the charging voltage of the original vehicle battery pack is within the output voltage range of the DC charging device, the DC charging device is turned on, and the DC charging device outputs a voltage matching the charging voltage of the original vehicle battery pack. The vehicle control module controls the first end and the second end of the second switch switching module to be connected, and the voltage can be directly delivered to the original vehicle battery pack via the adapter and the second switch switching module to realize charging of the original vehicle battery pack.

[0017] When the charging voltage of the original vehicle battery pack is not within the output voltage range of the DC charging device, the vehicle control module controls the boost module to boost the initial voltage of the vehicle to a preset voltage, and uses the preset voltage as the virtual charging voltage of the original vehicle battery pack to be delivered to the DC charging device. Since the preset voltage is within the output voltage range of the DC charging device, the DC charging device can be normally turned on. At this time, the vehicle control module will send a corresponding signal to the DC charging device, causing the DC charging device to adjust the output voltage to the charging voltage of the original vehicle battery pack. The voltage output by the DC charging device is delivered to the second switch switching module through the adapter. At this time, the first voltage detection module will perform voltage detection. If the voltage detected by the first voltage detection module matches the charging voltage of the original vehicle battery pack, it indicates that the DC charging device has successfully adjusted the output voltage to the charging voltage of the original vehicle battery pack. Then the vehicle control module controls the first end and the second end of the second switch switching module to be connected, so that the voltage can be directly delivered to the original vehicle battery pack through the adapter and the second switch switching module, realizing the charging of the original vehicle battery pack. If the voltage detected by the first voltage detection module does not match the charging voltage of the original vehicle battery pack, it indicates that the DC charging device has not adjusted the output voltage to the charging voltage of the original vehicle battery pack. Then the vehicle control module controls the first end and the fourth end of the second switch switching module to be connected, so that the voltage output by the DC charging device is delivered to the voltage conversion module through the adapter and the second switch switching module. The voltage conversion module converts the voltage to the charging voltage of the original vehicle battery pack and then delivers it to the original vehicle battery pack, realizing the charging of the original vehicle battery pack. Furthermore, this application realizes the automatic detection of the adapter, and based on the detection result of the adapter, controls the vehicle to switch from AC charging to DC charging, and in some cases, it can directly perform low-voltage DC charging on the original vehicle battery pack without using the DC / DC module, and the solution is simpler.

[0018] According to an embodiment of the present application, the first switch switching module includes a first switch element, a second switch element, a third switch element, and a fourth switch element. The first switch element is electrically connected to the CC port of the adapter and the in-vehicle OBC. The second switch element is electrically connected to the CC port of the adapter and the vehicle control module. The third switch element is electrically connected to the CP port of the adapter and the in-vehicle OBC. The fourth switch element is electrically connected to the CP port of the adapter and the vehicle control module.

[0019] According to an embodiment of the present application, the second switch switching module includes a fifth switch element. A first end of the fifth switch element is electrically connected to a power output end of the adapter. A second end of the fifth switch element is electrically connected to the original vehicle battery pack. A third end of the fifth switch element is electrically connected to the vehicle control module. A fourth end of the fifth switch element is electrically connected to the voltage conversion module. The vehicle control module is adapted to control the fifth switch element to switch between a first state and a second state. Wherein, in the first state, the fifth switch element connects the power output end of the adapter and the original vehicle battery pack. In the second state, the fifth switch element connects the power output end of the adapter and the voltage conversion module.

[0020] According to an embodiment of the present application, the electric vehicle DC charging system includes a third switch switching module. A first end of the third switch switching module is electrically connected to a power output end of the adapter. A second end of the third switch switching module is electrically connected to the on-vehicle OBC. The vehicle control module is electrically connected to the third switch switching module. The on-vehicle OBC is electrically connected to the original vehicle battery pack.

[0021] According to an embodiment of the present application, the electric vehicle DC charging system includes a second voltage detection module. The second voltage detection module is electrically connected to a first end of the third switch switching module. The second voltage detection module is electrically connected to the vehicle control module. The second voltage detection module is used to detect the magnitude of the voltage transmitted from the DC charging device to the third switch switching module through the adapter.

[0022] According to an embodiment of the present application, the electric vehicle DC charging system includes an on-vehicle step-down power supply. An input end of the on-vehicle step-down power supply is electrically connected to the on-vehicle OBC. An output end of the on-vehicle step-down power supply is adapted to be electrically connected to on-vehicle devices. The on-vehicle OBC is adapted to transmit electrical energy to the on-vehicle step-down power supply so that the on-vehicle step-down power supply charges the on-vehicle devices.

[0023] According to an embodiment of the second aspect of the present application, an electric vehicle includes the above-mentioned electric vehicle DC charging system.

[0024] The electric vehicle according to the present application has the above-mentioned electric vehicle DC charging system, and thus has all the technical effects of the above-mentioned electric vehicle DC charging system, which will not be elaborated here.

[0025] According to an embodiment of the present application, the DC charging system of the electric vehicle includes a third voltage detection module. The third voltage detection module is electrically connected to the power input terminal of the adapter. The power input terminal of the adapter is electrically connected to the DC charging device. The third voltage detection module is connected to the vehicle control module. The third voltage detection module is adapted to detect the magnitude of the voltage delivered by the DC charging device to the adapter.

[0026] According to an embodiment of the third aspect of the present application, the DC charging method of the electric vehicle includes:

[0027] Obtain the detection data of the resistance detection module to determine that the adapter is connected to the vehicle charging socket;

[0028] Obtain the charging voltage of the original vehicle battery pack;

[0029] Obtain the output voltage of the DC charging device;

[0030] If the difference between the charging voltage and the output voltage is within a preset range, then control the output voltage to charge the original vehicle battery pack;

[0031] If the difference between the charging voltage and the output voltage is not within the preset range, then control the output voltage to be delivered to the voltage conversion module, and control the voltage conversion module to convert the output voltage into a preset voltage to charge the original vehicle battery pack.

[0032] According to an embodiment of the present application, determine a target in-vehicle device that has an electric energy storage function;

[0033] Control the adapter to deliver the voltage of the DC charging device to the in-vehicle OBC;

[0034] Control the in-vehicle OBC to deliver the voltage to the in-vehicle step-down power supply;

[0035] Control the in-vehicle step-down power supply to charge the target in-vehicle device.

[0036] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 is the schematic diagram of the DC charging system for electric vehicles provided by the embodiments of the present application;

[0039] Figure 2 is one of the partial schematic diagrams of the DC charging system for electric vehicles provided by the embodiments of the present application;

[0040] Figure 3 is the schematic diagram of the low-power switching circuit of the in-vehicle step-down power supply provided by the embodiments of the present application;

[0041] Figure 4 is the circuit diagram of the low-power switching circuit of the in-vehicle step-down power supply provided by the embodiments of the present application;

[0042] Figure 5 is another circuit diagram of the first switch circuit provided by the embodiments of the present application;

[0043] Figure 6 is another circuit diagram of the second switch circuit provided by the embodiments of the present application;

[0044] Figure 7 is the second of the partial schematic diagrams of the DC charging system for electric vehicles provided by the embodiments of the present application. Detailed implementation manners

[0045] The following further describes the implementation manners of the present application in detail in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0046] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0047] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0048] In the embodiments of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0049] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0050] The following will be combined with Figures 1 to 7 to describe the DC charging system for electric vehicles, electric vehicles and DC charging methods of the present application.

[0051] According to the embodiments of the first aspect of the present application, as Figure 1 shown, a DC charging system for an electric vehicle, adapted to be connected to an adapter, the adapter being adapted to be connected to a DC charging device, the DC charging system for an electric vehicle includes:

[0052] A vehicle control module;

[0053] A first switch switching module, a first end of the first switch switching module is electrically connected to the communication port of the adapter, a second end of the first switch switching module is electrically connected to the vehicle control module, and a third end of the second switch switching control module is electrically connected to the on-vehicle OBC;

[0054] A resistance detection module, electrically connected to the vehicle control module, the resistance detection module is electrically connected to the adapter to detect the resistance of the adapter;

[0055] A second switch switching module, a first end of the second switch switching module is electrically connected to the power output end of the adapter, a second end of the second switch switching module is electrically connected to the original vehicle battery pack, and a third end of the second switch switching module is electrically connected to the vehicle control module;

[0056] A voltage conversion module is electrically connected between the fourth terminal of the second switch switching module and the original vehicle battery pack;

[0057] A first voltage detection module is electrically connected to the first terminal of the second switch switching module. The first voltage detection module is electrically connected to the vehicle control module. The first voltage detection module is adapted to detect the magnitude of the voltage delivered by the DC charging device to the second switch switching module via the adapter;

[0058] A boost module is electrically connected to the vehicle control module. The boost module is electrically connected to the DC charging device. The boost module is adapted to boost the initial voltage of the vehicle to a preset voltage and then deliver it to the DC charging device.

[0059] In the electric vehicle DC charging system according to the embodiment of the present application, when the adapter is connected to the vehicle charging socket, the resistance detection module will detect the resistance of the adapter and transmit the detection result to the vehicle control module, so that the vehicle control module can determine whether the device connected to the vehicle charging socket is the adapter. When it is determined that the adapter is connected to the vehicle charging socket, the vehicle control module controls the first terminal and the second terminal of the first switch switching module to be connected, so that the communication port of the adapter is connected to the vehicle control module, and the vehicle control module can interact with the DC charging device through the communication port of the adapter.

[0060] The vehicle control module obtains the charging voltage of the original vehicle battery pack and the output voltage range of the DC charging device, and compares the charging voltage of the original vehicle battery pack with the output voltage range of the DC charging device. When the charging voltage of the original vehicle battery pack is within the output voltage range of the DC charging device, the DC charging device is turned on, and the DC charging device outputs a voltage matching the charging voltage of the original vehicle battery pack. The vehicle control module controls the first terminal and the second terminal of the second switch switching module to be connected, and the voltage can be directly delivered to the original vehicle battery pack via the adapter and the second switch switching module to achieve charging of the original vehicle battery pack.

[0061] When the charging voltage of the original vehicle battery pack is not within the output voltage range of the DC charging device, the vehicle control module controls the boost module to boost the initial voltage of the vehicle to a preset voltage, and uses the preset voltage as the virtual charging voltage of the original vehicle battery pack to be delivered to the DC charging device. Since the preset voltage is within the output voltage range of the DC charging device, the DC charging device can be normally turned on. At this time, the vehicle control module will send a corresponding signal to the DC charging device, causing the DC charging device to adjust the output voltage to the charging voltage of the original vehicle battery pack. The voltage output by the DC charging device is delivered to the second switch switching module through the adapter. At this time, the first voltage detection module will perform voltage detection. If the voltage detected by the first voltage detection module matches the charging voltage of the original vehicle battery pack, it indicates that the DC charging device has successfully adjusted the output voltage to the charging voltage of the original vehicle battery pack. Then the vehicle control module controls the first end and the second end of the second switch switching module to be connected, so that the voltage can be directly delivered to the original vehicle battery pack through the adapter and the second switch switching module, realizing the charging of the original vehicle battery pack. If the voltage detected by the first voltage detection module does not match the charging voltage of the original vehicle battery pack, it indicates that the DC charging device has not adjusted the output voltage to the charging voltage of the original vehicle battery pack. Then the vehicle control module controls the first end and the fourth end of the second switch switching module to be connected, so that the voltage output by the DC charging device is delivered to the voltage conversion module through the adapter and the second switch switching module. The voltage conversion module converts the voltage into the charging voltage of the original vehicle battery pack and then delivers it to the original vehicle battery pack, realizing the charging of the original vehicle battery pack. Furthermore, the present application realizes the automatic detection of the adapter, and based on the detection result of the adapter, controls the vehicle to switch from AC charging to DC charging, and in some cases, can directly perform low-voltage DC charging on the original vehicle battery pack without using the DC / DC module, and the solution is simpler.

[0062] It can be understood that when the resistance value detected by the resistance detection module matches the preset adapter resistance value, it indicates that the adapter is connected to the vehicle charging socket at this time, rather than the DC charging device.

[0063] It can be understood that when the adapter is not connected to the vehicle charging socket, but the AC charging device is directly connected to the vehicle charging socket, the in-vehicle OBC can be controlled to charge the original vehicle battery pack.

[0064] It can be understood that the initial voltage is the standing voltage of the vehicle, which can be 12V, can be 24V, can be 48V, or any other suitable voltage value.

[0065] It can be understood that the preset voltage is, for example, 300V or any other voltage within the output voltage range value of the DC charging device.

[0066] In an embodiment of the present application, as Figure 7As shown in the figure, various ports of the DC adapter are shown. Specifically, the adapter includes DC+, DC-, S+, S-, CC2, CC1, A+, A-, L1, N, L2, L3, CC, CP, and two grounding ports PE. DC+, DC-, S+, S-, CC2, CC1, A+, A-, and one of the grounding ports PE are used to connect to the DC charging device, and L1, N, L2, L3, CC, CP, and the other grounding port PE are used to connect to the vehicle's charging socket. Among them, DC+ and DC- are the power input ports of the adapter, S+ and S- are the communication access ports, L1 and N are the first power output ports of the adapter, L2 and L3 are the second power output ports of the adapter, and CC and CP are the communication output ports.

[0067] In an embodiment of the present application, both the CC port and the PE port of the adapter are electrically connected to the resistance detection module, and the resistance detection module is adapted to detect the resistance values at the CC port and the PE port of the adapter. During use, the resistance detection module can detect the resistance values of the CC port and the PE port of the adapter. Compared with the related art where the DC charging device is detected by detecting the CC port, in the present application, by directly detecting the resistance value between the two ports of the adapter, the resistance of the adapter can be detected more accurately, enabling the vehicle control module to more accurately determine whether the adapter is connected to the vehicle's charging socket.

[0068] Exemplarily, the resistance detection module can detect the voltage between the CC port and the PE port of the adapter, and by judging the resistance value corresponding to the voltage, the resistance value between the CC port and the PE port of the adapter can be obtained.

[0069] In an embodiment of the present application, as Figure 7 shown, the first switch switching module includes a first switch element, a second switch element, a third switch element, and a fourth switch element. The first switch element is electrically connected to the CC port of the adapter and the in-vehicle OBC, the second switch element is electrically connected to the CC port of the adapter and the vehicle control module, the third switch element is electrically connected to the CP port of the adapter and the in-vehicle OBC, and the fourth switch element is electrically connected to the CP port of the adapter and the vehicle control module.

[0070] During use, the vehicle control module can separately control the opening and closing of the first switch element, the second switch element, the third switch element, and the fourth switch element. When the resistance detection module detects the resistance of the adapter, that is, after determining that the adapter is connected to the vehicle charging socket, the vehicle control module controls the second switch element and the fourth switch element to close, so that the CC port and the CP port of the adapter are connected to the vehicle control module, and the vehicle control module can interact with the DC charging device through the adapter. When the adapter is not inserted into the vehicle charging socket, it is defaulted to AC charging, and the vehicle control module controls the first switch element and the third switch element to close, so that the in-vehicle OBC can interact with the AC charging device through the first switch element and the third switch element. This application realizes that it can judge whether the adapter is inserted into the vehicle charging socket according to the detection result of the resistance detection module, and further can control the vehicle to automatically switch between the DC charging circuit and the AC charging circuit.

[0071] It should be noted that the first switch element, the second switch element, the third switch element, and the fourth switch element can also be closed simultaneously, that is, the vehicle control module and the in-vehicle OBC are simultaneously connected to the adapter, and the in-vehicle OBC and the vehicle control module can simultaneously interact with the DC charging device.

[0072] In an embodiment of the present application, the second switch switching module includes a fifth switch element. The first end of the fifth switch element is electrically connected to the power output end of the adapter, the second end of the fifth switch element is electrically connected to the original vehicle battery pack, the third end of the fifth switch element is electrically connected to the vehicle control module, and the fourth end of the fifth switch element is electrically connected to the voltage conversion module. The vehicle control module is adapted to control the fifth switch element to switch between a first state and a second state. Among them, in the first state, the fifth switch element connects the power output end of the adapter and the original vehicle battery pack, and in the second state, the fifth switch element connects the power output end of the adapter and the voltage conversion module.

[0073] When the charging voltage of the original vehicle battery pack is within the output voltage range of the DC charging device and the DC charging device can directly output a voltage that matches the charging voltage of the original vehicle battery pack, or when the first voltage detection module detects that the voltage delivered to the fifth switching element matches the charging voltage of the original vehicle battery pack, the vehicle control module controls the fifth switching element to be in the first state, enabling the power output terminal of the adapter to be directly connected to the original vehicle battery pack, and the DC charging device can directly charge the original vehicle battery pack. When the first voltage detection module detects that the voltage value is not within the charging range value of the original vehicle battery pack, it indicates that the power cannot be directly delivered to the original vehicle battery pack at this time. The vehicle control module then controls the fifth switching element to be in the second state, causing the power output terminal of the adapter to be connected to the voltage conversion module. The DC charging device transmits the power to the voltage conversion module, and after the voltage conversion module converts the voltage, it outputs a voltage that meets the charging requirements of the original vehicle battery pack to the original vehicle battery pack, which can prevent damage to the original vehicle battery pack.

[0074] Moreover, the second switch switching module and the first voltage detection module can also be used for the insulation detection of the charging pile: control the DC charging device to output the maximum voltage. The voltage output by the DC charging device can be delivered to the second switch switching module through the adapter. At this time, the second switch switching module is in the off state, and the first voltage detection module detects the voltage and delivers the detected voltage to the DC charging device. The DC charging device can compare the detected voltage with the maximum voltage output by the DC charging device. If the two are different, the DC+ and DC- power output terminals of the DC charging device are disconnected.

[0075] In an embodiment of the present application, the first switching element, the second switching element, the third switching element, the fourth switching element, and the fifth switching element are, for example, relays.

[0076] In an embodiment of the present application, as Figure 2 shown, the DC charging system for electric vehicles includes a third switch switching module. The first end of the third switch switching module is electrically connected to the power output terminal of the adapter, the second end of the third switch switching module is electrically connected to the on-vehicle OBC, the vehicle control module is electrically connected to the third switch switching module, and the on-vehicle OBC is electrically connected to the original vehicle battery pack.

[0077] During use, the first voltage detection module detects the magnitude of the voltage delivered by the DC charging device to the second switch switching module via the adapter. When the voltage detected by the first voltage detection module is within the charging voltage range of the original vehicle battery pack, the vehicle control module controls the first and second ends of the second switch switching module to be connected, enabling the electrical energy of the DC charging device to be directly delivered to the original vehicle battery pack via the adapter and the second switch switching module, thereby achieving DC charging of the original vehicle battery pack. When the voltage detected by the first voltage detection module is not within the charging voltage range of the original vehicle battery pack, the vehicle control module controls the first and second ends of the second switch switching module to be disconnected, and the first and fourth ends of the second switch switching module to be connected, causing the electrical energy of the DC charging device to be delivered to the voltage conversion module via the adapter and the second switch switching module. After the voltage conversion module converts the voltage of the DC charging device to within the charging voltage range of the original vehicle battery pack, it is then delivered to the original vehicle battery pack to achieve DC charging of the original vehicle battery pack. When the magnitude of the voltage detected by the first voltage detection module exceeds the processing capacity of the voltage conversion module, i.e., the voltage conversion module is unable to convert the current voltage, the vehicle control module will control the first and second ends of the third switch switching module to be connected, causing the voltage output by the DC charging device to be delivered to the in-vehicle OBC via the adapter. The in-vehicle OBC converts the voltage to within the charging voltage range of the original vehicle battery pack and then delivers it to the original vehicle battery pack to achieve the DC charging function of the original vehicle battery pack. That is to say, when the output voltage of the DC charging device is too high, the in-vehicle OBC can be used to achieve DC charging of the original vehicle battery pack; when the output voltage of the DC charging device is higher than the charging voltage range of the original vehicle battery pack but within the processing capacity of the voltage conversion module, the voltage conversion module can be used to convert the voltage and then charge the original vehicle battery pack, which can also achieve DC charging of the original vehicle battery pack; when the output voltage of the DC charging device is within the charging voltage range of the original vehicle battery pack, the voltage can be directly delivered to the original vehicle battery pack to achieve DC charging of the original vehicle battery pack.

[0078] It should be noted that the third switch switching module can also be switched between open and closed in any other suitable situation, and the in-vehicle OBC can also perform other functions, not limited to the functions described above.

[0079] It should be noted that the in-vehicle OBC in this embodiment is an AC / DC dual-purpose OBC, and the AC / DC dual-purpose OBC is an existing module, so no further description will be given here.

[0080] In an embodiment of the present application, the electric vehicle DC charging system includes a second voltage detection module. The second voltage detection module is electrically connected to the first end of the third switch switching module and electrically connected to the vehicle control module. The second voltage detection module is used to detect the magnitude of the voltage delivered by the DC charging device to the third switch switching module via the adapter.

[0081] During use, the in-vehicle OBC is connected to the communication port of the adapter, and the in-vehicle OBC can interact with the DC charging device. The second voltage detection module can detect the magnitude of the voltage delivered by the DC charging device to the third switch switching module and transmit the detection result to the vehicle control module. When the voltage detected by the second voltage detection module is within the input voltage range of the in-vehicle OBC, the vehicle control module controls the first end and the second end of the third switch switching module to be connected, so that the voltage can be delivered to the in-vehicle OBC, and then after being processed by the in-vehicle OBC, it charges the original vehicle battery pack. When the voltage detected by the second voltage detection module is not within the input voltage range of the in-vehicle OBC, it indicates that the current DC charging device is not suitable for the current vehicle or the DC charging device has a fault. Then the vehicle control module controls the third switch switching module to be in the off state to prevent too high a voltage from being delivered to the in-vehicle OBC and causing damage to the in-vehicle OBC.

[0082] Moreover, the third switch switching module and the second voltage detection module can also be used for the insulation detection of the charging pile: control the DC charging device to output the maximum voltage. The voltage output by the DC charging device can be delivered to the third switch switching module through the adapter. At this time, the third switch switching module is in the off state, and the second voltage detection module detects the voltage and delivers the detected voltage to the DC charging device. The DC charging device can compare the detected voltage with the maximum voltage output by the DC charging device. If the two are different, the DC+ and DC- power output terminals of the DC charging device are disconnected.

[0083] In an embodiment of the present application, as Figure 2 shown, the electric vehicle DC charging system includes an in-vehicle buck power supply. The input end of the in-vehicle buck power supply is electrically connected to the in-vehicle OBC, and the output end of the in-vehicle buck power supply is adapted to be electrically connected to the in-vehicle device. The in-vehicle OBC is adapted to transmit electrical energy to the in-vehicle buck power supply so that the in-vehicle buck power supply charges the in-vehicle device.

[0084] During use, the DC charging device transmits the voltage to the original vehicle battery pack through the adapter to perform DC charging on the original vehicle battery pack. At the same time, the adapter also transmits the voltage to the in-vehicle OBC, and the in-vehicle OBC transmits the voltage to the in-vehicle buck power supply, so that the in-vehicle buck power supply can supply power or charge the in-vehicle device. Furthermore, when the vehicle is charging, the power consumed by using the in-vehicle device is not the power of the original vehicle battery pack, which can accelerate the charging speed of the original vehicle battery pack. Moreover, it can charge the in-vehicle device while charging the original vehicle battery pack, improving the charging amount of the vehicle, enabling the in-vehicle device not to consume the power of the original vehicle battery pack within a certain period of subsequent use, and improving the cruising range of the vehicle.

[0085] It can be understood that some in-vehicle devices come with their own power modules, and thus can be charged.

[0086] In an embodiment of the present application, as Figure 3 shown, the in-vehicle step-down power supply includes an in-vehicle step-down power supply low-power switching circuit, which is adapted to be electrically connected to at least two in-vehicle devices. The two in-vehicle devices are the first in-vehicle device and the second in-vehicle device respectively. The in-vehicle step-down power supply low-power switching circuit includes a single-chip microcomputer 1, a power-down detection circuit, and at least two switching circuits. The at least two switching circuits are the first switching circuit 2 and the second switching circuit 3;

[0087] The control end of the first switching circuit 2 is electrically connected to the single-chip microcomputer 1. One end of the first switching circuit 2 is electrically connected to the first power supply, and the other end of the first switching circuit 2 is electrically connected to the first in-vehicle device. The first switching circuit 2 is adapted to control whether the first power supply supplies power to the first in-vehicle device;

[0088] The control end of the second switching circuit 3 is electrically connected to the single-chip microcomputer 1. One end of the second switching circuit 3 is electrically connected to the second power supply, and the other end of the second switching circuit 3 is electrically connected to the second in-vehicle device. The first MOS transistor Q1 is adapted to control whether the second power supply supplies power to the second in-vehicle device;

[0089] The power-down detection circuit is electrically connected to the first in-vehicle device and the second in-vehicle device respectively. The power-down detection circuit is adapted to detect whether the first in-vehicle device and the second in-vehicle device are powered down.

[0090] According to the in-vehicle step-down power supply low-power switching circuit of the embodiment of the present application, the power-down detection circuit detects in real time whether the first in-vehicle device and the second in-vehicle device have been powered down, that is, whether they are in a non-operating state, and transmits the detection data to the single-chip microcomputer 1. When the power-down detection circuit detects that the first in-vehicle device has been powered down, the single-chip microcomputer 1 controls the first switching circuit 2 to be in a cut-off state through the control end of the first switching circuit 2, so that the first power supply stops supplying power to the first in-vehicle device, avoiding the first in-vehicle device from continuing to consume power. When the power-down detection circuit detects that the second in-vehicle device has been powered down, the single-chip microcomputer 1 controls the second switching circuit 3 to be in a cut-off state through the control end of the second switching circuit 3, so that the second power supply stops supplying power to the second in-vehicle device, avoiding the second in-vehicle device from continuing to consume power. Thus, it realizes timely detection of whether the in-vehicle device has been powered down, can timely disconnect the power supply of the in-vehicle device, avoid the in-vehicle device from continuing to consume power, effectively save electric energy, and the first switching circuit 2 and the second switching circuit 3 are respectively connected to an in-vehicle device, so that one or more in-vehicle devices can be controlled separately for power on and off. It can also avoid useless power consumption of the in-vehicle device during vehicle charging and improve the charging efficiency of the vehicle.

[0091] It should be noted that the power-down detection circuit can be any suitable circuit with a power-down detection function. The improvement of this application lies in applying the power-down detection circuit to the circuit of the vehicle-mounted step-down power supply to realize the detection of whether the vehicle-mounted device is powered down, so as to timely disconnect the power supply of the vehicle-mounted device.

[0092] In an embodiment of the present application, as Figure 4 shown, the first switch circuit is, for example, a first MOS transistor switch circuit. The first MOS transistor switch circuit includes a first connection end, a first resistor R1, a second resistor R2, and a first MOS transistor Q1. The first connection end is electrically connected to the sixty-second end of the single-chip microcomputer 1 and one end of the first resistor R1. The other end of the first resistor R1 is electrically connected to the gate of the first MOS transistor Q1. One end of the second resistor R2 and the gate of the first MOS transistor Q1 are electrically connected. The other end of the second resistor R2 is electrically connected to the source of the first MOS transistor Q1. The source of the first MOS transistor Q1 is electrically connected to the first power supply. The drain of the first MOS transistor Q1 is electrically connected to the first vehicle-mounted device.

[0093] It can be understood that through the sixty-second end and the first connection end, the single-chip microcomputer 1 can send corresponding control signals to the first MOS transistor switch circuit, so that the first MOS transistor Q1 switches between the on state and the off state. The source of the first MOS transistor Q1 is electrically connected to the first power supply, and the drain of the first MOS transistor Q1 is electrically connected to the first vehicle-mounted device. Then when the first MOS transistor Q1 is in the off state, the first power supply and the first vehicle-mounted device are not connected, that is, the first power supply cannot supply power to the first vehicle-mounted device. Furthermore, when the first vehicle-mounted device is not in use, power consumption can be avoided.

[0094] It should be noted that the first switch circuit can also be a relay circuit.

[0095] In an embodiment of the present application, as Figure 4 shown, the first MOS transistor switch circuit includes a first inductor L1. One end of the first inductor L1 is electrically connected to the source of the first MOS transistor Q1, and the other end of the first inductor L1 is electrically connected to the drain of the first MOS transistor Q1.

[0096] It can be understood that by electrically connecting the first inductor L1 between the source and the drain of the first MOS transistor Q1, the first inductor L1, the first MOS transistor Q1, the first resistor R1, and the second resistor R2 together form the first MOS transistor switch circuit. The first inductor L1 can play a filtering role, and the setting of the first inductor L1 can make the first MOS transistor switch circuit more stable and reliable.

[0097] In an embodiment of the present application, as Figure 4As shown, the second switch circuit is, for example, a second MOS transistor switch circuit. The second MOS transistor switch circuit includes a second connection terminal, a third resistor R3, a fourth resistor R4, and a second MOS transistor Q2. The second connection terminal is electrically connected to the sixty-second terminal of the single-chip microcomputer 1 and one end of the third resistor R3. The other end of the third resistor R3 is electrically connected to the gate of the second MOS transistor Q2. One end of the fourth resistor R4 is electrically connected to the gate of the second MOS transistor Q2, and the other end of the fourth resistor R4 is electrically connected to the source of the second MOS transistor Q2. The source of the second MOS transistor Q2 is electrically connected to a second power supply, and the drain of the second MOS transistor Q2 is electrically connected to a second vehicle-mounted device.

[0098] It can be understood that through the sixty-second terminal and the second connection terminal, the single-chip microcomputer 1 can send corresponding control signals to the second MOS transistor switch circuit, so that the second MOS transistor Q2 switches between the on state and the off state. Since the source of the second MOS transistor Q2 is electrically connected to the second power supply and the drain of the second MOS transistor Q2 is electrically connected to the second vehicle-mounted device, when the second MOS transistor Q2 is in the off state, the second power supply and the second vehicle-mounted device are not connected, that is, the second power supply cannot supply power to the second vehicle-mounted device. Thus, when the second vehicle-mounted device is not in use, power consumption can be avoided.

[0099] It should be noted that the second switch circuit can also be a relay circuit.

[0100] In an embodiment of the present application, as Figure 4 shown, the second MOS transistor switch circuit includes a second inductor L2. One end of the second inductor L2 is electrically connected to the source of the second MOS transistor Q2, and the other end of the second inductor L2 is electrically connected to the drain of the second MOS transistor Q2.

[0101] It can be understood that by electrically connecting the second inductor L2 between the source and the drain of the second MOS transistor Q2, the second inductor L2, the second MOS transistor Q2, the third resistor R3, and the fourth resistor R4 together form the second MOS transistor switch circuit. The second inductor L2 can play a filtering role, and the setting of the second inductor L2 can make the second MOS transistor switch circuit more stable and reliable.

[0102] In an embodiment of the present application, as Figure 5As shown, the first MOS transistor switching circuit includes a third connection terminal, a third MOS transistor Q3, a fifth resistor R5, a sixth resistor R6, and a first capacitor C1. The third connection terminal is electrically connected to the sixty-second terminal of the single-chip microcomputer 1 and one end of the fifth resistor R5. The other end of the fifth resistor R5 is electrically connected to the gate of the third MOS transistor Q3. One end of the sixth resistor R6 is electrically connected to one end of the fifth resistor R5. The other end of the sixth resistor R6 is electrically connected to the source of the MOS transistor. One end of the first capacitor C1 is electrically connected to the other end of the fifth resistor R5. The other end of the first capacitor C1 is electrically connected to the source of the third MOS transistor Q3. The source of the third MOS transistor Q3 is electrically connected to the first power supply. The drain of the third MOS transistor Q3 is electrically connected to the first in-vehicle device. When in use, the single-chip microcomputer 1 can control the first MOS transistor switching circuit through the third connection terminal, electrically connect the fifth resistor R5 and the first capacitor C1 to the third MOS transistor Q3 respectively, so that the first capacitor C1, the third MOS transistor Q3, and the fifth resistor R5 form the first MOS transistor switching circuit, enabling the first MOS transistor switching circuit to limit the inrush current when the first power supply is turned on.

[0103] In an embodiment of the present application, as Figure 6 shown, the second MOS transistor switching circuit includes a fourth connection terminal, a fourth MOS transistor Q4, a seventh resistor R7, an eighth resistor R8, and a second capacitor C2. The fourth connection terminal is electrically connected to the forty-third terminal of the single-chip microcomputer 1 and one end of the seventh resistor R7. The other end of the seventh resistor R7 is electrically connected to the gate of the fourth MOS transistor Q4. One end of the eighth resistor R8 is electrically connected to one end of the seventh resistor R7. The other end of the eighth resistor R8 is electrically connected to the source of the MOS transistor. One end of the second capacitor C2 is electrically connected to the other end of the seventh resistor R7. The other end of the second capacitor C2 is electrically connected to the source of the fourth MOS transistor Q4. The source of the fourth MOS transistor Q4 is electrically connected to the second power supply. The drain of the fourth MOS transistor Q4 is electrically connected to the second in-vehicle device. When in use, the single-chip microcomputer 1 can control the second MOS transistor switching circuit through the fourth connection terminal, electrically connect the seventh resistor R7 and the second capacitor C2 to the fourth MOS transistor Q4 respectively, so that the second capacitor C2, the fourth MOS transistor Q4, and the seventh resistor R7 form the second MOS transistor switching circuit, enabling the second MOS transistor switching circuit to limit the inrush current when the second power supply is turned on.

[0104] In one embodiment of the present application, the first MOS transistor switching circuit includes a fifth connection terminal, a fifth MOS transistor, and a ninth resistor. The fifth connection terminal is electrically connected to the sixty-second terminal of the single-chip microcomputer 1 and the gate of the fifth MOS transistor. The two ends of the ninth resistor are respectively electrically connected to the source and drain of the fifth MOS transistor. The source of the fifth MOS transistor is electrically connected to the first power supply, and the drain of the fifth MOS transistor is electrically connected to the first vehicle-mounted device. During use, the single-chip microcomputer 1 can control the first MOS transistor switching circuit through the fifth connection terminal, electrically connect the two ends of the ninth resistor to the source and drain of the fifth MOS transistor respectively, so that the fifth MOS transistor and the ninth resistor form the first MOS transistor switching circuit. The setting of the ninth resistor enables the first MOS transistor switching circuit to limit the inrush current when the first power supply is turned on.

[0105] In one embodiment of the present application, the second MOS transistor switching circuit includes a sixth connection terminal, a sixth MOS transistor, and a tenth resistor. The sixth connection terminal is electrically connected to the forty-third terminal of the single-chip microcomputer 1 and the gate of the sixth MOS transistor. The two ends of the tenth resistor are respectively electrically connected to the source and drain of the sixth MOS transistor. The source of the sixth MOS transistor is electrically connected to the second power supply, and the drain of the sixth MOS transistor is electrically connected to the second vehicle-mounted device. During use, the single-chip microcomputer 1 can control the second MOS transistor switching circuit through the sixth connection terminal, electrically connect the two ends of the tenth resistor to the source and drain of the sixth MOS transistor respectively, so that the sixth MOS transistor and the tenth resistor form the second MOS transistor switching circuit. The setting of the tenth resistor enables the second MOS transistor switching circuit to limit the inrush current when the second power supply is turned on.

[0106] According to an embodiment of the second aspect of the present application, an electric vehicle includes the above-mentioned DC charging system for electric vehicles.

[0107] The electric vehicle according to the embodiment of the present application has a DC charging system for electric vehicles, which realizes automatic detection of the adapter, and based on the adapter detection result, controls the vehicle to switch from AC charging to DC charging, and realizes direct low-voltage DC charging of the original vehicle battery pack using an AC charging socket without using a DC / DC module, and the solution is simpler.

[0108] In one embodiment of the present application, the DC charging system for electric vehicles includes a third voltage detection module. The third voltage detection module is electrically connected to the power input terminal of the adapter. The power input terminal of the adapter is electrically connected to the DC charging device. The third voltage detection module is connected to the vehicle control module, and the third voltage detection module is adapted to detect the magnitude of the voltage delivered by the DC charging device to the adapter.

[0109] During use, the third voltage detection module can detect the magnitude of the voltage delivered by the DC charging device to the adapter and transmit the detection result to the vehicle control module. When the voltage detected by the third voltage detection module is zero, it indicates that the DC charging device has stopped outputting voltage. After the vehicle finishes charging, the vehicle control module can determine whether the DC charging device has been powered off, that is, whether the DC charging device has stopped outputting voltage, based on the detection result of the third voltage detection module. After determining that the DC charging device has stopped outputting voltage, the vehicle control module enters the sleep mode to prevent the vehicle control module from entering the sleep mode when the DC charging device has not been completely powered off.

[0110] It can be understood that the connection between the third voltage detection module and the vehicle control module can be a communication connection, a direct electrical connection, or a connection implemented through other components.

[0111] In an embodiment of the present application, a fourth switch switching module is provided between the adapter and the DC charging device. The first end of the fourth switch switching module is electrically connected to the DC charging device, the second end of the fourth switch switching module is electrically connected to the adapter, an adapter control module is provided inside the adapter, the adapter control module is electrically connected to the fourth switch switching module, and the third voltage detection module is electrically connected to the adapter control module.

[0112] During use, the third voltage detection module detects the voltage delivered by the DC charging device to the adapter and transmits the detection data to the adapter control module. When the voltage detected by the third voltage detection module is within the safe operating voltage range of the adapter, the adapter control module controls the fourth switch switching module to close, so that the first end and the second end of the fourth switch switching module are connected, and the DC charging device can transmit the voltage to the adapter. The present application realizes the detection of the output voltage of the DC charging device, and the voltage will be transmitted to the adapter only after it is detected that the voltage is within the safe operating voltage range of the adapter, ensuring the safety of the adapter.

[0113] According to an embodiment of the third aspect of the present application, a method for DC charging of an electric vehicle includes:

[0114] Obtain the detection data of the resistance detection module to determine the connection between the adapter and the vehicle charging socket;

[0115] Obtain the charging voltage of the original vehicle battery pack;

[0116] Obtain the output voltage of the DC charging device;

[0117] If the difference between the charging voltage and the output voltage is within a preset range, then control the output voltage to charge the original vehicle battery pack;

[0118] If the difference between the charging voltage and the output voltage is not within the preset range, then control the output voltage to be delivered to the voltage conversion module, and control the voltage conversion module to convert the output voltage into a preset voltage to charge the original vehicle battery pack.

[0119] Furthermore, the automatic detection of the adapter is realized, and based on the detection result of the adapter, the vehicle is controlled to switch from AC charging to DC charging, and in some cases, the original vehicle battery pack can be directly charged with low-voltage DC without using the DC / DC module, and the solution is simpler.

[0120] According to an embodiment of the present application, the DC charging method for an electric vehicle includes:

[0121] Determine a target in-vehicle device, where the target in-vehicle device has an electric energy storage function;

[0122] Control the adapter to deliver the voltage of the DC charging device to the in-vehicle OBC;

[0123] Control the in-vehicle OBC to deliver the voltage to the in-vehicle buck power supply;

[0124] Control the in-vehicle buck power supply to charge the target in-vehicle device.

[0125] The DC charging device transmits the voltage to the original vehicle battery pack through the adapter to charge the original vehicle battery pack with DC. At the same time, the adapter also transmits the voltage to the in-vehicle OBC, and the in-vehicle OBC transmits the voltage to the in-vehicle buck power supply, so that the in-vehicle buck power supply can charge the target in-vehicle device. Furthermore, when the vehicle is charging, the user can charge the in-vehicle device, which increases the charging amount of the vehicle, enables the in-vehicle device not to consume the power of the original vehicle battery pack within a certain period of subsequent use, and improves the cruising range of the vehicle.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that various combinations, modifications, or equivalent replacements of the technical solutions of the present application do not depart from the spirit and scope of the technical solutions of the present application, and should all be covered by the scope of the claims of the present application.

Claims

1. A DC charging system for an electric vehicle, adapted to be connected to an adapter, and the adapter is adapted to be connected to a DC charging device, characterized in that, Including: A vehicle control module; A first switch switching module, the first end of the first switch switching module is electrically connected to the communication port of the adapter, the second end of the first switch switching module is electrically connected to the vehicle control module, and the third end of the first switch switching module is electrically connected to the on-vehicle OBC; A resistance detection module, electrically connected to the vehicle control module, and the resistance detection module is electrically connected to the adapter to detect the resistance of the adapter; A second switch switching module, the first end of the second switch switching module is electrically connected to the power output end of the adapter, the second end of the second switch switching module is electrically connected to the original vehicle battery pack, and the third end of the second switch switching module is electrically connected to the vehicle control module; A voltage conversion module, electrically connected between the fourth end of the second switch switching module and the original vehicle battery pack; A first voltage detection module, electrically connected to the first end of the second switch switching module, the first voltage detection module is electrically connected to the vehicle control module, and the first voltage detection module is adapted to detect the magnitude of the voltage transmitted from the DC charging device to the second switch switching module through the adapter; A boost module, electrically connected to the vehicle control module, the boost module is electrically connected to the DC charging device, and the boost module is adapted to boost the initial voltage of the vehicle to a preset voltage and then transmit it to the DC charging device; After the adapter is connected to the vehicle charging socket, the resistance detection module detects the resistance of the adapter and transmits the detection result to the vehicle control module, so that the vehicle control module can determine whether the adapter is currently connected to the vehicle charging socket; when it is determined that the adapter is connected to the vehicle charging socket, the vehicle control module controls the first end and the second end of the first switch switching module to be connected, so that the communication port of the adapter and the vehicle control module are connected, and the vehicle control module interacts with the DC charging device through the communication port of the adapter; the vehicle control module obtains the charging voltage of the original vehicle battery pack and the output voltage range of the DC charging device, and compares the charging voltage of the original vehicle battery pack with the output voltage range of the DC charging device; When the charging voltage of the original vehicle battery pack is within the output voltage range of the DC charging device, the DC charging device is turned on, and the DC charging device outputs a voltage matching the charging voltage of the original vehicle battery pack. The vehicle control module controls the first end and the second end of the second switch switching module to be connected, and the voltage is directly transmitted to the original vehicle battery pack through the adapter and the second switch switching module to realize the charging of the original vehicle battery pack; When the charging voltage of the original vehicle battery pack is not within the output voltage range of the DC charging device, the vehicle control module controls the boost module to boost the initial voltage of the vehicle to a preset voltage, and uses the preset voltage as the virtual charging voltage of the original vehicle battery pack to be delivered to the DC charging device. Since the preset voltage is within the output voltage range of the DC charging device, the DC charging device is normally turned on. At this time, the vehicle control module sends a corresponding signal to the DC charging device, causing the DC charging device to adjust the output voltage to the charging voltage of the original vehicle battery pack; the voltage output by the DC charging device is delivered to the second switch switching module through the adapter. At this time, the first voltage detection module performs voltage detection; if the voltage detected by the first voltage detection module matches the charging voltage of the original vehicle battery pack, the vehicle control module controls the first end and the second end of the second switch switching module to be connected, so that the voltage is directly delivered to the original vehicle battery pack through the adapter and the second switch switching module, realizing the charging of the original vehicle battery pack; if the voltage detected by the first voltage detection module does not match the charging voltage of the original vehicle battery pack, the vehicle control module controls the first end and the fourth end of the second switch switching module to be connected, so that the voltage output by the DC charging device is delivered to the voltage conversion module through the adapter and the second switch switching module. The voltage conversion module converts the voltage into the charging voltage of the original vehicle battery pack and then delivers it to the original vehicle battery pack to realize the charging of the original vehicle battery pack.

2. The DC charging system for electric vehicles according to claim 1, characterized in that, The first switch switching module includes a first switch element, a second switch element, a third switch element, and a fourth switch element. The first switch element is electrically connected to the CC port of the adapter and the in-vehicle OBC. The second switch element is electrically connected to the CC port of the adapter and the vehicle control module. The third switch element is electrically connected to the CP port of the adapter and the in-vehicle OBC. The fourth switch element is electrically connected to the CP port of the adapter and the vehicle control module.

3. The DC charging system for electric vehicles according to claim 1, characterized in that, The second switch switching module includes a fifth switch element. The first end of the fifth switch element is electrically connected to the power output end of the adapter. The second end of the fifth switch element is electrically connected to the original vehicle battery pack. The third end of the fifth switch element is electrically connected to the vehicle control module. The fourth end of the fifth switch element is electrically connected to the voltage conversion module. The vehicle control module is adapted to control the fifth switch element to switch between a first state and a second state. Among them, in the first state, the fifth switch element connects the power output end of the adapter and the original vehicle battery pack. In the second state, the fifth switch element connects the power output end of the adapter and the voltage conversion module.

4. The DC charging system for an electric vehicle according to any one of claims 1 to 3, characterized in that, The electric vehicle DC charging system includes a third switch switching module. The first end of the third switch switching module is electrically connected to the power output end of the adapter. The second end of the third switch switching module is electrically connected to the in-vehicle OBC. The vehicle control module is electrically connected to the third switch switching module. The in-vehicle OBC is electrically connected to the original vehicle battery pack.

5. The DC charging system for electric vehicles according to claim 4, wherein, The electric vehicle DC charging system includes a second voltage detection module. The second voltage detection module is electrically connected to the first end of the third switch switching module, and the second voltage detection module is electrically connected to the vehicle control module. The second voltage detection module is used to detect the magnitude of the voltage delivered by the DC charging device to the third switch switching module via the adapter.

6. The DC charging system for an electric vehicle according to claim 5, characterized in that, The electric vehicle DC charging system includes an in-vehicle step-down power supply. The input end of the in-vehicle step-down power supply is electrically connected to the in-vehicle OBC, and the output end of the in-vehicle step-down power supply is adapted to be electrically connected to in-vehicle devices. The in-vehicle OBC is adapted to transmit electrical energy to the in-vehicle step-down power supply so that the in-vehicle step-down power supply charges the in-vehicle devices.

7. An electric vehicle, characterized in that, It includes the electric vehicle DC charging system according to any one of claims 1 to 6.

8. The electric vehicle according to claim 7, wherein The electric vehicle DC charging system includes a third voltage detection module. The third voltage detection module is electrically connected to the power input end of the adapter. The power input end of the adapter is electrically connected to the DC charging device. The third voltage detection module is connected to the vehicle control module. The third voltage detection module is adapted to detect the magnitude of the voltage delivered by the DC charging device to the adapter.

9. An electric vehicle DC charging method for the electric vehicle DC charging system according to any one of claims 1 to 6, characterized in that, It includes: Obtain the detection data of the resistance detection module and determine that the adapter is connected to the vehicle charging socket; Obtain the charging voltage of the original vehicle battery pack; Obtain the output voltage of the DC charging device; If the difference between the charging voltage and the output voltage is within a preset range, then control the output voltage to charge the original vehicle battery pack; If the difference between the charging voltage and the output voltage is not within the preset range, then control the output voltage to be delivered to the voltage conversion module, and control the voltage conversion module to convert the output voltage into a preset voltage to charge the original vehicle battery pack.

10. The DC charging method for an electric vehicle according to claim 9, characterized in that, It includes: Determine the target in-vehicle device, and the target in-vehicle device has an electrical energy storage function; Control the adapter to deliver the voltage of the DC charging device to the in-vehicle OBC; Control the in-vehicle OBC to deliver the voltage to the in-vehicle step-down power supply; Control the in-vehicle step-down power supply to charge the target in-vehicle device.

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