Vehicle charging system and vehicle

Abstract

This invention relates to the field of vehicle technology, specifically providing a vehicle charging system and a vehicle, aiming to solve the problem of how to safely and effectively use charging facilities when the voltage levels of the power battery and the charging facility are mismatched. The vehicle charging system of this invention may include a voltage conversion device, a charging port capacitor, a power distribution device, and a charging control device. The charging control device can control the power battery, voltage conversion device, power distribution device, and charging port capacitor to form different conduction circuits, control the power battery to pre-charge the charging port capacitor through the conduction circuit, and control the charging port capacitor to discharge through the conduction circuit. Based on the above embodiments, not only can the voltage conversion device accommodate charging facilities of different voltage levels, but the charging port capacitor can also be pre-charged and discharged through the aforementioned conduction circuits, achieving safe and effective charging even when the voltage levels of the power battery and the charging facility are mismatched.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, specifically providing a vehicle charging system and a vehicle. Background Technology

[0002] With the rapid development of electric vehicle technology, the voltage level of the high-voltage system in electric vehicles is also constantly increasing, such as from 400V to 800V. However, charging facilities are limited by factors such as cost and cannot be upgraded in a timely manner, resulting in the charging facilities being unable to adapt to the rapid changes in the voltage level of the high-voltage system in electric vehicles. To solve this problem, patent application CN112600411A discloses a voltage conversion device. This voltage conversion device reuses the inverter and motor winding in the power control unit (PEU) of an electric vehicle to realize the boost function from a second DC voltage, such as 400V, to a first DC voltage, such as 800V. It can convert the lower voltage provided by the charging facility to a higher voltage to charge the power battery, thus accommodating charging facilities with different voltage levels on the market.

[0003] However, in practical applications, electric vehicles (EVs) have a charging port capacitor on the side connected to the charging facility. This capacitor needs to be pre-charged during charging to prevent surge current damage to the charging relay when it closes in the EV's high-voltage system. Simultaneously, the capacitor needs to be discharged at the end of charging to prevent electric shock from stored energy when disconnecting the EV from the charging facility, such as by unplugging the charging gun. The aforementioned patent application does not disclose how to pre-charge and discharge the charging port capacitor, potentially posing significant safety risks when using the voltage conversion device disclosed in the patent application for EV charging. Summary of the Invention

[0004] To overcome the above-mentioned deficiencies, the present invention is proposed to provide a vehicle charging system and a vehicle that solves, or at least partially solves, the technical problem of how to safely and effectively use a charging facility to charge a vehicle when the voltage level of the power battery in the vehicle is mismatched with that of the charging facility.

[0005] In a first aspect, the present invention provides a vehicle charging system, the vehicle including a power battery and an electric drive system, the electric drive system including an inverter and an electric motor, the DC side of the inverter being connected to the power battery, the AC side of the inverter being connected to the stator winding of the electric motor, the charging system including a voltage conversion device, the voltage conversion device including the inverter, the stator winding, a first positive terminal, a second positive terminal, and a negative terminal, the first positive terminal and the negative terminal being respectively connected to the positive and negative terminals of the DC side, the second positive terminal being connected to the center tap of the stator winding, the charging system further including a charging port capacitor, a power distribution device, and a charging control device, the power distribution device being respectively connected to the voltage conversion device and the charging port capacitor;

[0006] The charging control device is configured to:

[0007] In response to the received charging start command, the system controls the power battery, the voltage conversion device, the power distribution device, and the charging port capacitor to form a conducting circuit, and controls the power battery to precharge the charging port capacitor through the conducting circuit;

[0008] In response to a received charging stop command, the voltage conversion device, the power distribution device, and the charging port capacitor are controlled to form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop.

[0009] In one technical solution of the above-mentioned vehicle charging system, the charging system further includes a charging port, which includes a positive input terminal and a negative input terminal;

[0010] The power distribution equipment includes a first switch, a second switch, and a third switch; the first end and the second end of the first switch are respectively connected to the first positive terminal and the positive input terminal; the first end and the second end of the second switch are respectively connected to the second positive terminal and the positive input terminal; and the first end and the second end of the third switch are respectively connected to the negative terminal and the negative input terminal.

[0011] The first and second ends of the charging port capacitor are respectively connected to the second end of the second switch and the first end of the third switch.

[0012] In one technical solution of the above-mentioned vehicle charging system, the charging control device includes a charging start control module, and the charging start control module includes a capacitor pre-charge sub-module;

[0013] The capacitor pre-charge submodule is configured to pre-charge the charging port capacitor by performing the following operations:

[0014] In response to the received charging start command, the second switch is closed and the first switch and the third switch are kept in the open state, so that the power battery, the voltage conversion device, the second switch and the charging port capacitor form a conducting circuit;

[0015] The voltage conversion device is controlled to step down the electrical energy output from the power battery, and the stepped-down electrical energy is transmitted to the charging port capacitor through the conduction circuit for pre-charging. Pre-charging stops when the voltage of the charging port capacitor reaches a set value.

[0016] In one technical solution of the above-mentioned vehicle charging system, the charging start control module further includes a first power battery charging sub-module;

[0017] The first power battery charging submodule is configured to charge the power battery by performing the following operations when the output voltage level of the external charging facility connected to the charging port matches the charging voltage level of the power battery:

[0018] After the pre-charging submodule stops pre-charging, the second switch is disconnected, then the first switch and the third switch are closed, and finally the connection switch between the charging port and the external charging facility is closed, so that the power battery, the voltage conversion device, the power distribution device, the charging port and the external charging facility form a charging circuit, and the external charging facility is controlled to charge the power battery through the charging circuit;

[0019] And / or,

[0020] The charging start control module also includes a second power battery charging sub-module;

[0021] The second power battery charging submodule is configured to charge the power battery by performing the following operations when the output voltage level of the external charging facility connected to the charging port does not match the charging voltage level of the power battery:

[0022] After the pre-charging submodule stops pre-charging, the second switch is disconnected, then the third switch is closed, and finally the connection switch between the charging port and the external charging facility is closed, so that the power battery, the voltage conversion device, the power distribution device, the charging port and the external charging facility form a charging circuit, and the external charging facility is controlled to charge the power battery through the charging circuit.

[0023] In one technical solution of the above-mentioned vehicle charging system, the charging control device includes a charging stop control module, and the charging stop control module includes a first charging stop control submodule;

[0024] The first charging stop control submodule is configured to discharge the charging port capacitor by performing the following operations when the output voltage level matches the charging voltage level:

[0025] In response to the received charging stop command, the connection switch between the charging port and the external charging facility is disconnected, then the first switch and the third switch are disconnected, and finally the second switch is closed to make the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop;

[0026] The charging stop command is a command to stop charging the power battery and, after stopping charging, to control the power battery to continue supplying power to the high-voltage system inside the vehicle.

[0027] In one technical solution of the above-mentioned vehicle charging system, the charging control device includes a charging stop control module, and the charging stop control module includes a second charging stop control sub-module;

[0028] The second charging stop control submodule is configured to discharge the charging port capacitor by performing the following operations when the output voltage level does not match the charging voltage level:

[0029] In response to a received charging stop command, the connection switch between the charging port and the external charging facility is disconnected, so that the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop;

[0030] The charging stop command is either an instruction to stop charging the power battery and, after stopping charging, to control the power battery to continue supplying power to the high-voltage system inside the vehicle, or an instruction to stop charging the power battery and, after stopping charging, to control the power battery to no longer supply power to the high-voltage system inside the vehicle.

[0031] In one technical solution of the above-mentioned vehicle charging system, the voltage conversion device further includes a discharge circuit connected in parallel with the DC side of the inverter. The discharge circuit includes a power electronic device and a resistor. The first main electrode of the power electronic device is connected to the positive terminal of the DC side, the second main electrode of the power electronic device is connected to the first end of the resistor, and the second end of the resistor is connected to the negative terminal of the DC side.

[0032] In one technical solution of the above-mentioned vehicle charging system, when the charging stop command is an instruction to stop charging the power battery and, after stopping charging, control the power battery to no longer supply power to the high-voltage system inside the vehicle, the first charging stop control submodule is further configured to discharge the charging port capacitor by performing the following operations when the output voltage level matches the charging voltage level:

[0033] In response to the received charging stop command, the connection switch is disconnected, then the first switch and the third switch are disconnected, the connection switch between the power battery and the inverter is disconnected, the second switch is closed, and finally the power electronic device is controlled to conduct, so that the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the discharge path.

[0034] In one technical solution of the aforementioned vehicle charging system, when the charging stop command is an instruction to stop charging the power battery and, after stopping charging, control the power battery to no longer supply power to the high-voltage system inside the vehicle, the second charging stop control submodule is further configured to discharge the charging port capacitor by performing the following operations when the output voltage level does not match the charging voltage level:

[0035] In response to the received charging stop command, the connection switch is disconnected, then the connection switch between the power battery and the inverter is disconnected, and finally the power electronic device is turned on so that the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop.

[0036] In a second aspect, a vehicle is provided, the vehicle including a power battery and an electric drive system, the electric drive system including an inverter and an electric motor, the DC side of the inverter being connected to the power battery, the AC side of the inverter being connected to the stator winding of the electric motor, and the vehicle further including the vehicle charging system described in any of the above-mentioned vehicle charging system technical solutions.

[0037] The above-described technical solutions of the present invention have at least one or more of the following beneficial effects:

[0038] In implementing the technical solution of the present invention, the vehicle charging system may include a voltage conversion device, a charging port capacitor, a power distribution device, and a charging control device, wherein the power distribution device is connected to the voltage conversion device and the charging port capacitor respectively.

[0039] A voltage conversion device can reuse a vehicle's electric drive system, which may include an inverter and a motor. The DC side of the inverter is connected to the power battery, and the AC side of the inverter is connected to the stator winding of the motor. The voltage conversion device may include the aforementioned inverter and stator winding, and may also include a first positive terminal, a second positive terminal, and a negative terminal. The first positive terminal and the negative terminal are respectively connected to the positive and negative terminals of the DC side of the inverter, and the second positive terminal is connected to the center tap of the stator winding. The first positive terminal, the second positive terminal, and the negative terminal constitute the external power input side of the voltage conversion device, and the DC side of the inverter constitutes the external power output side of the voltage conversion device. When the output voltage level of the external power supply connected to the external power input side matches the supply voltage level of the load connected to the external power output side, the output power of the external power supply can be directly transmitted to the load. When the output voltage level of the external power supply does not match the supply voltage level of the load, the output power of the external power supply can be voltage converted before the voltage-converted power is transmitted to the load.

[0040] The charging control device can be configured to, in response to a received charging start command, control the power battery, voltage conversion device, power distribution device, and charging port capacitor to form a conducting circuit, and control the power battery to pre-charge the charging port capacitor through the conducting circuit. By pre-charging the charging port capacitor, the charging switch of the high-voltage system in the vehicle can be closed (e.g., closed...). Figure 2 When the power battery 1 is connected to the inverter via switches Kpos+ and Kneg-, surge current will not be generated that could damage the charging switch.

[0041] Furthermore, the charging control device can also be configured to, in response to a received charging stop command, control the voltage conversion device, power distribution device, and charging port capacitor to form a conducting loop, and control the charging port capacitor to discharge through the conducting loop. By discharging the charging port capacitor, it is possible to prevent the user from disconnecting the vehicle from the external power source (e.g., disconnecting...). Figure 2 When the charging port is disconnected from the external charging facility (switches K4 and K5 shown), the electrical energy stored in the capacitor of this charging port can cause an electric shock to the user.

[0042] Based on the above implementation method, not only can the voltage conversion device be used to accommodate charging facilities with different voltage levels on the market, but the charging port capacitor can also be pre-charged and discharged through the conduction circuit formed by the charging control device and power distribution device, so that the charging facility can be used to charge the vehicle safely and effectively even when the voltage levels of the vehicle and the charging facility are mismatched. Attached Figure Description

[0043] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:

[0044] Figure 1 This is a schematic diagram of the main structure of a vehicle charging system according to an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of the main structure of a vehicle charging system according to another embodiment of the present invention;

[0046] Figure 3 This is an adoption of an embodiment of the present invention. Figure 2 The diagram shows the vehicle charging system and its status when an 800V charging pile is used to charge the 800V power battery.

[0047] Figure 4 This is an adoption of an embodiment of the present invention. Figure 2 The diagram shows the vehicle charging system when a 400V charging pile is used to charge an 800V power battery.

[0048] Figure 5 This is a schematic flowchart of the main steps for pre-charging the charging port capacitor according to an embodiment of the present invention.

[0049] Figure 6 This is a schematic diagram of the main steps for discharging the charging port capacitor after charging an 800V power battery using an 800V charging pile, according to an embodiment of the present invention.

[0050] Figure 7 This is a schematic diagram of the main steps for discharging the charging port capacitor after charging an 800V power battery using a 400V charging pile, according to an embodiment of the present invention.

[0051] List of reference numerals :

[0052] 1: Power battery; 2: Voltage conversion equipment; 3: Power distribution equipment; 4: Charging port; 21: First positive terminal; 22: Second positive terminal; 23: Negative terminal; 41: Positive input terminal of charging port; 42: Negative input terminal of charging port. Detailed Implementation

[0053] Some embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0054] In the description of this invention, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, memory, and may also include software components, such as program code, or a combination of software and hardware. A processor can be a central processing unit, a microprocessor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor can be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media include any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms.

[0055] The terminology involved in this invention will be explained below.

[0056] Power electronic devices can be fully controllable power semiconductor devices, such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), or integrated-gate commutated thyristors (IGCTs). These fully controllable power semiconductor devices are all three-terminal devices; for example, a MOSFET includes a source, drain, and gate; an IGBT includes a collector, emitter, and gate; and an IGCT includes a collector, emitter, and gate. The source, drain, collector, and emitter are the main electrodes, while the gate and gate are the control electrodes. To clearly describe the main electrodes of power electronic devices, this invention refers to the main electrodes in the power input direction as the first main electrode (such as the drain of a MOSFET and the collector of an IGBT), and the main electrodes in the power output direction as the second main electrode (such as the source of a MOSFET and the emitter of an IGBT).

[0057] See appendix Figure 1 , Figure 1This is a main structural block diagram of a vehicle charging system according to an embodiment of the present invention. In this embodiment, the vehicle may include a power battery and an electric drive system. The electric drive system may include an inverter and a motor. The DC side of the inverter is connected to the power battery, and the AC side of the inverter is connected to the stator winding of the motor. The inverter can convert the DC power output from the power battery into AC power, thereby enabling the motor to operate under the control of the AC power to provide power for driving the vehicle. Figure 1 As shown, in this embodiment of the invention, the vehicle charging system may include a power battery 1, a voltage conversion device 2, a power distribution device 3, a charging port 4, and a charging control device. Figure 1 (Not shown), the above structures will be explained in detail below.

[0058] 1. Voltage conversion equipment 2

[0059] In this embodiment of the invention, the voltage conversion device 2 may include the inverter and the stator winding of the motor in the above-mentioned electric drive system. The three-phase stator winding of the motor is connected in a Y-type connection to form a center tap. In addition, the voltage conversion device 2 may also include a first positive terminal 21, a second positive terminal 22, and a negative terminal 23. The first positive terminal 21 and the negative terminal 23 are respectively connected to the positive and negative terminals of the DC side, and the second positive terminal 22 is connected to the center tap of the stator winding.

[0060] See appendix Figure 2 The inverter can be a three-phase full-bridge inverter, which includes three phase arms, each phase arm comprising an upper arm and a lower arm. The upper and lower arms of the first phase arm include power electronic devices Q1 and Q2, respectively; the upper and lower arms of the second phase arm include power electronic devices Q3 and Q4, respectively; and the upper and lower arms of the third phase arm include power electronic devices Q5 and Q6, respectively. These three phase arms are connected to the three-phase stator winding L, which is connected in a Y-type configuration to form a center tap. The first positive terminal 21 of the voltage conversion device 2 is connected to the positive terminal of the DC side in the inverter, the second positive terminal 22 is connected to the center tap of the three-phase stator winding L, and the negative terminal 23 is connected to the negative terminal of the DC side in the inverter.

[0061] Please refer to the appendix for further details. Figure 2In this embodiment, the first positive terminal 21, the second positive terminal 22, and the negative terminal 23 constitute the external power input side of the voltage conversion device 2, and the DC side of the inverter constitutes the external power output side of the voltage conversion device 2. When the output voltage level of the external power supply connected to the external power input side matches the supply voltage level of the load connected to the external power output side (e.g., they are equal), the first positive terminal 21 and the negative terminal 23 can be controlled to connect to the external power supply, so that the DC power output by the external power supply can be directly input to the load for power supply through the first positive terminal 21 and the negative terminal 23, as well as the positive and negative terminals of the DC side of the inverter. When the output voltage level of the external power supply does not match the supply voltage level of the load, the second positive terminal 22 and the negative terminal 23 can be controlled to connect to the external power supply, and the inverter can be controlled to perform voltage conversion on the DC power input from the second positive terminal 22 and the negative terminal 23, and then input the voltage-converted DC power to the load for power supply through the positive and negative terminals of the DC side of the inverter. For example, if the output voltage level of the external power supply is lower than the supply voltage level of the load, the inverter can be controlled to perform a step-up conversion on the aforementioned DC power.

[0062] See appendix again Figure 1 In this embodiment of the invention, the load connected to the external power supply output side can be the vehicle's power battery, and the external power supply connected to the external power supply input side can be an external charging facility capable of charging the power battery. When the output voltage level of the external charging facility matches the charging voltage level of the power battery, the first positive terminal 21 and the negative terminal 23 are controlled to connect to the external charging facility; when the output voltage level of the external charging facility does not match the charging voltage level of the power battery, the second positive terminal 22 and the negative terminal 23 are controlled to connect to the external charging facility. Furthermore, in this embodiment, the voltage conversion device disclosed in patent application CN112600411A can be used; the specific structure and working principle of this voltage conversion device will not be described in detail here.

[0063] II. Power Distribution Equipment 3

[0064] In this embodiment of the invention, the power distribution device 3 can be connected to the voltage conversion device 2 and the charging port capacitor respectively. Figure 1(Not shown) Connection. The power distribution device 3 can be configured to switch the connection between the voltage conversion device 2 and the charging port capacitor in response to commands sent by the charging control device. This allows the power battery 1, voltage conversion device 2, power distribution device 3, and charging port capacitor to form a conductive loop when pre-charging or discharging of the charging port capacitor is required. This conductive loop allows for pre-charging or discharging of the charging port capacitor. Simultaneously, the power distribution device 3 can be configured to switch the connection between the voltage conversion device 2 and the charging port capacitor in response to commands sent by the charging control device. This allows the power battery 1, voltage conversion device 2, power distribution device 3, charging port 4, and external charging facilities to form a charging loop, which allows charging of the power battery 1.

[0065] See appendix Figure 2 In one embodiment, the power distribution device 3 may include a first switch K1, a second switch K2, and a third switch K3. The first and second terminals of the first switch K1 are respectively connected to the first positive terminal 21 and the positive input terminal 41 of the charging port 4. The first and second terminals of the second switch K2 are respectively connected to the second positive terminal 22 and the positive input terminal 41. The first and second terminals of the third switch K3 are respectively connected to the negative terminal 23 and the negative input terminal 42 of the charging port 4. The first and second terminals of the charging port capacitor Cport are respectively connected to the second terminal of the second switch K2 and the first terminal of the third switch K3.

[0066] As can be seen from the aforementioned implementation of voltage conversion device 2, when the output voltage level of the external charging facility matches the charging voltage level of the power battery 1, the first positive terminal 21 and the negative terminal 23 can be connected to the external charging facility, so that the DC power output by the external charging facility can be directly input to the power battery 1 for charging via the first positive terminal 21 and the negative terminal 23, as well as the positive and negative terminals on the DC side of the inverter. (See appendix) Figure 3 When the output voltage level of the external charging facility matches the charging voltage level of the power battery 1, the first switch K1 can be closed to connect the first positive terminal 21 to the positive input terminal of the charging port 4, and the third switch K3 can be closed to connect the negative terminal 23 to the negative input terminal of the charging port 4. Simultaneously, the second switch K2 can be opened. Through the aforementioned switch control, the power battery 1, voltage conversion device 2, power distribution device 3, and external charging facility can form a charging circuit, through which the external charging facility can charge the power battery. Since the charging port capacitor Cport is connected to this charging circuit, it is necessary to pre-charge the charging port capacitor Cport before charging the power battery, and also to discharge the charging port capacitor Cport when charging is finished.

[0067] When the output voltage level of the external charging facility does not match the charging voltage level of the power battery 1, the second positive terminal 22 and negative terminal 23 can be connected to the external charging facility, allowing the DC power output from the external charging facility to be directly input to the power battery 1 for charging via the positive and negative terminals on the DC side of the inverter connected to the second positive terminal 22 and negative terminal 23. (See appendix) Figure 4 When the output voltage level of the external charging facility does not match the charging voltage level of the power battery 1, the second switch K2 can be closed to connect the second positive terminal 22 to the positive input terminal of the charging port 4, and the third switch K3 can be closed to connect the negative terminal 23 to the negative input terminal of the charging port 4. Simultaneously, the first switch K1 is opened. Thus, through the aforementioned switch control, the power battery 1, voltage conversion device 2, power distribution device 3, and external charging facility can form a charging circuit, through which the external charging facility can charge the power battery. Since the charging port capacitor Cport is connected to this charging circuit, it is necessary to pre-charge the charging port capacitor Cport before charging the power battery, and also to discharge the charging port capacitor Cport when charging is finished.

[0068] III. Charging Control Equipment

[0069] In embodiments of the present invention, the charging control device can be configured to perform the following operations:

[0070] In response to a received charging start command, the system controls the power battery 1, voltage conversion device 2, power distribution device 3, and charging port capacitor to form a conducting circuit, and controls the power battery 1 to pre-charge the charging port capacitor through this conducting circuit; and in response to a received charging stop command, the system controls the voltage conversion device 2, power distribution device 3, and charging port capacitor to form a conducting circuit, and controls the charging port capacitor to discharge through this conducting circuit.

[0071] A charging start command is an instruction to begin charging the vehicle's battery using charging facilities, while a charging stop command is an instruction to stop charging the vehicle's battery using charging facilities.

[0072] In one embodiment of the present invention, the charging control device may include a charging start control module, and the charging start control module may include a capacitor pre-charge sub-module. In this embodiment, the capacitor pre-charge sub-module may be configured to... Figure 2 The power distribution device 3 shown precharges the charging port capacitor Cport by performing the following operations:

[0073] Step 11: In response to the received charging start command, close the second switch K2 and control the first switch K1 and the third switch K3 to remain open, so that the power battery 1, the voltage conversion device 2, the second switch K2 and the charging port capacitor Cport form a conducting circuit.

[0074] Step 12: The voltage conversion device 2 steps down the output power of the power battery 1, and the stepped-down power is transmitted to the charging port capacitor Cport for pre-charging through the conduction circuit formed in step 11. Pre-charging stops when the voltage of the charging port capacitor Cport reaches a set value. In other words, the power battery 1 uses the stored power energy to pre-charge the charging port capacitor Cport. Before pre-charging, the output power of the power battery 1 is stepped down to match the voltage level of the output power energy of the power battery 1 with the charging voltage level of the charging port capacitor Cport. Then, the power battery 1 is used to pre-charge the charging port capacitor Cport.

[0075] In this embodiment, the inverter arms in the voltage conversion device 2 can be switched on / off to enable the voltage conversion device 2 to step down the electrical energy output from the power battery 1. For example, all upper arms of the inverter can be controlled to remain on (i.e., power electronic devices Q1, Q3, and Q5 can be controlled to remain on), and all lower arms can be controlled to remain off (i.e., power electronic devices Q2, Q4, and Q6 can be controlled to remain off). Alternatively, all upper arms of the inverter can be controlled to be on for a certain period of time, and then all upper arms can be controlled to be off. During the on period of upper arm conduction, all lower arms can be controlled to be off, and during the off period of upper arms, all lower arms can be controlled to be on, and the on time of the upper arms is longer than the on time of the lower arms.

[0076] Furthermore, in this embodiment of the invention, the charging start control module may further include a first power battery charging submodule and a second power battery charging submodule. When the charging port capacitor is pre-charged by the capacitor pre-charging submodule, either the first power battery charging submodule or the second power battery charging submodule can be used to charge the power battery. The first power battery charging submodule and the second power battery charging submodule will be described in detail below.

[0077] 1. First power battery charging sub-module

[0078] In this embodiment of the invention, the first power battery charging submodule can be configured to use... Figure 2 When the output voltage level of the power distribution device 3 shown and the external charging facility connected to the charging port 4 matches the charging voltage level of the power battery 1, the power battery 1 is charged by performing the following operations:

[0079] After the capacitor pre-charging submodule stops pre-charging, the second switch K2 is disconnected, followed by the first switch K1 and the third switch K3, and finally the connection switch between charging port 4 and the external charging facility is closed. Figure 2 The switches K4 and K5 shown are used to form a charging circuit between the power battery 1, voltage conversion device 2, power distribution device 3, charging port 4 and external charging facilities, and to control the external charging facilities to charge the power battery 1 through this charging circuit.

[0080] 2. Second power battery charging sub-module

[0081] In this embodiment of the invention, the second power battery charging submodule can be configured to use... Figure 2 When the output voltage level of the power distribution device 3 shown and the external charging facility connected to the charging port 4 does not match the charging voltage level of the power battery 1, the power battery is charged by performing the following operations:

[0082] After the capacitor pre-charging submodule stops pre-charging, the second switch K2 is disconnected, then the third switch K3 is closed, and finally the connection switch between charging port 4 and the external charging facility is closed. Figure 2 The switches K4 and K5 shown are used to form a charging circuit between the power battery 1, voltage conversion device 2, power distribution device 3, charging port 4, and external charging facility, and to control the external charging facility to charge the power battery 1 through this charging circuit. Referring to the aforementioned embodiment of voltage conversion device 2, during the power battery charging stage, when the output voltage level of the external charging facility does not match the charging voltage level of the power battery 1, it is necessary to control the voltage conversion device 2 to perform energy conversion, such as boosting, on the DC power output by the external charging facility so that the converted DC power matches the charging voltage level of the power battery 1.

[0083] The following example uses external charging facilities as charging piles, along with related information. Figure 5 ,right Figure 2 The following further illustrates the pre-charge control method for the charging port capacitor of the vehicle charging system. In this embodiment, the charging voltage level of the vehicle's power battery 1 is 800V. See Appendix Figure 5 The pre-charge control method for the charging port capacitor may include the following steps S101-S105:

[0084] Step S101: After detecting the charging gun insertion, the handshake phase begins, and the connection switches K4 and K5 between the charging port 4 and the external charging facility are closed and then disconnected. In other words, the handshake phase begins after the charging gun of the charging pile is detected inserted into the vehicle's charging port (plug-in). During the handshake phase, the connection switches K4 and K5 are controlled to close first and then disconnect.

[0085] Step S102: Detect whether the output voltage level of the external charging facility is 800V or 400V. If the detected output voltage level is 800V, it indicates that the output voltage level of the external charging facility matches the charging voltage level of the power battery 1. Then, execute steps S1031-S1034, and proceed to step S105 after completion. If the detected output voltage level is 400V, it indicates that the output voltage level of the external charging facility does not match the charging voltage level of the power battery 1. Then, execute steps S1041-S1044, and proceed to step S105 after completion.

[0086] Step S1031: Close the second switch K2.

[0087] Step S1032: Control the voltage conversion device 2 to step down the electrical energy output by the power battery 1 and precharge the charging port capacitor.

[0088] Step S1033: After pre-charging is completed, control the voltage conversion device 2 to stop working and disconnect the second switch K2.

[0089] Step S1034: Close the first switch K1 and the third switch K3.

[0090] Step S1041: Close the second switch K2.

[0091] Step S1042: Control the voltage conversion device 2 to step down the electrical energy output by the power battery 1 and precharge the charging port capacitor.

[0092] Step S1043: After pre-charging is completed, control the voltage conversion device 2 to stop working.

[0093] Step S1044: Close the third switch K3.

[0094] Step S105: Close the connection switches K4 and K5 between the charging port 4 and the external charging facility. After the connection switches K4 and K5 are closed, the external charging facility can be controlled to charge the power battery 1. During the power battery charging stage, the control method of the voltage conversion device 2 can be referred to the aforementioned method embodiment, and will not be repeated here.

[0095] In one embodiment of the present invention, the charging control device may include a charging stop control module. This module is configured to, after stopping charging of the power battery, form a discharge circuit for the charging port capacitor by controlling the voltage conversion device 2 and the power distribution device 3, and control the charging port capacitor to discharge through this circuit. This ensures that the stored energy in the charging port capacitor is promptly discharged after charging of the power battery stops, preventing electric shock or other safety accidents when the user disconnects the external charging facility from the vehicle charging system. In this embodiment, the charging stop control module may include a first charging stop control submodule and a second charging stop control submodule. When the output voltage level of the external charging facility matches the charging voltage level of the power battery, the charging port capacitor can be discharged through the first charging stop control submodule. When the output voltage level of the external charging facility does not match the charging voltage level of the power battery, the charging port capacitor can be discharged through the second charging stop control submodule. The first and second charging stop control submodules are described in detail below.

[0096] 1. First charging stop control submodule

[0097] In this embodiment of the invention, the charging stop command may include an instruction to stop charging the power battery and, after stopping charging, control the power battery to continue supplying power to the high-voltage system inside the vehicle (hereinafter referred to as the first charging stop command), or an instruction to stop charging the power battery and, after stopping charging, control the power battery to no longer supply power to the high-voltage system inside the vehicle (hereinafter referred to as the second charging stop command). Wherein, controlling the power battery to continue supplying power to the high-voltage system inside the vehicle after stopping charging means that even after the power battery stops charging, it is still necessary to use the power battery to supply power to the high-voltage system inside the vehicle, such as high-voltage accessories in the high-voltage system like the air conditioner, on-board charger (OBC), and DC / DC converter.

[0098] The following sections provide specific explanations for the two charging stop commands mentioned above.

[0099] (1) First charging stop command

[0100] In this embodiment, the first charging stop control submodule can be configured to use... Figure 2 When the power distribution device 3 shown is configured such that its output voltage level matches the charging voltage level, the charging port capacitor is discharged by performing the following operations:

[0101] In response to the received charging stop command, disconnect the connection switch between charging port 4 and the external charging facility. Figure 2The switches K4 and K5 are shown. Then the first switch K1 and the third switch K3 are opened. Finally, the second switch K2 is closed so that the voltage conversion device 2, the power distribution device 3 and the charging port capacitor Cport form a conducting loop, and the charging port capacitor Cport is controlled to discharge through this conducting loop.

[0102] In this embodiment, the inverter's bridge arm in the voltage conversion device 2 can be switched on / off, so that the charging port capacitor Cport forms multiple short-term conduction loops with the lower bridge arm in the inverter. After each conduction loop is formed, the charging port capacitor Cport can be discharged through this conduction loop.

[0103] See appendix Figure 2 First, control power electronic device Q2 to conduct (while turning off all other power electronic devices), so that the charging port capacitor Cport, stator winding L, and power electronic device Q2 form a conducting circuit. The discharge current flows from the positive terminal of the charging port capacitor Cport (the end connected to the second switch K2) through the second positive terminal 22, stator winding L, power electronic device Q2, and negative terminal 23, and then flows back into the negative terminal of the charging port capacitor Cport (the end connected to the second switch K3). Then, control power electronic device Q4 to conduct (while turning off all other power electronic devices), so that the charging port capacitor Cport, stator winding L, and power electronic device Q2 form a conducting circuit. The discharge current flows from the positive terminal of the charging port capacitor Cport (the end connected to the second switch K2) through the second positive terminal 22, stator winding L, power electronic device Q2, and negative terminal 23, and then flows back into the negative terminal of the charging port capacitor Cport (the end connected to the second switch K3). Then, the power electronic device Q6 is turned on (all other power electronic devices are turned off), forming a conducting circuit with the charging port capacitor Cport, the stator winding L, and the power electronic device Q2. The discharge current flows from the positive terminal of the charging port capacitor Cport (the end connected to the second switch K2) through the second positive terminal 22, the stator winding L, the power electronic device Q2, and the negative terminal 23, before flowing back into the negative terminal of the charging port capacitor Cport (the end connected to the second switch K3). Finally, the above process is repeated until the voltage of the charging port capacitor Cport drops to a preset value, such as 60V, at which point the discharge control stops.

[0104] (2) Second charging stop command

[0105] In this embodiment, refer to the appendix. Figure 2The voltage conversion device 2 may also include a discharge circuit connected in parallel with the DC side of the inverter. This discharge circuit may include a power electronic device Qdischarge and a resistor Rdischarge. The first main electrode of the power electronic device Qdischarge is connected to the positive terminal of the DC side, the second main electrode of the power electronic device Qdischarge is connected to the first terminal of the resistor Rdischarge, and the second terminal of the resistor Rdischarge is connected to the negative terminal of the DC side. In other words, the power electronic device Qdischarge and the resistor Rdischarge are connected in series and then in parallel with the DC side of the inverter.

[0106] The first charging stop control submodule can be configured to use... Figure 2 When the power distribution device 3 shown above is used and its output voltage level matches the charging voltage level, the above-described discharge circuit is employed, and the charging port capacitor is discharged by performing the following operations:

[0107] In response to the received charging stop command, disconnect the connection switch between charging port 4 and the external charging facility. Figure 2 Switches K4 and K5 (as shown) are then disconnected, followed by the first switch K1 and the third switch K3, thus disconnecting the connection between the power battery 1 and the inverter. Figure 2 The switches Kpos+ and Kneg- shown close the second switch K2, ultimately controlling the power electronic device Qdischarge to conduct, so that the voltage conversion device 2, the power distribution device 3, and the charging port capacitor Cport form a conducting loop, and controlling the charging port capacitor Cport to discharge through this conducting loop. In one embodiment, switches Kpos+ and Kneg- can be relays, such as normally open relays.

[0108] In this embodiment, each power electronic device in the voltage conversion device 2 is connected in reverse parallel with a diode, such as... Figure 2 As shown, power electronic devices Q1-Q6 and power electronic device Qdischarge are each connected in reverse parallel with a diode. After power electronic device Qdischarge is turned on, the charging port capacitor Cport can not only be connected in parallel with the conducting circuit (parallel branch), but also form a series branch through the diodes in each upper arm of the inverter in voltage conversion device 2, and then be connected in parallel with the DC bus capacitor Cbus of the inverter (series-parallel branch). In other words, the conducting circuit formed after power electronic device Qdischarge is turned on includes both the above-mentioned parallel branch and series-parallel branch. The charging port capacitor Cport can discharge not only through the above-mentioned parallel branch, but also through the above-mentioned series-parallel branch, thereby significantly improving the discharge speed of the charging port capacitor Cport.

[0109] The following example uses external charging facilities as charging piles, along with related information. Figure 6 ,right Figure 2 The following further illustrates the discharge control method for the charging port capacitor of the vehicle charging system. In this embodiment, the charging voltage level of the vehicle's internal power battery 1 is 800V, and the output voltage level of the external charging facility is also 800V. (See appendix...) Figure 6 The discharge control method for the charging port capacitor may include the following steps S201-S205:

[0110] Step S201: Detect whether the power battery 1 continues to supply power to the high-voltage system after the 800V charging is completed; if it continues to supply power, proceed to step S204 after executing steps S2021-S2023; if it no longer supplies power, proceed to step S2031-S2033 and then proceed to step S204.

[0111] Step S2021: First disconnect the connection switches K4 and K5 between the charging port 4 and the external charging facility, and then disconnect the first switch K1 and the third switch K3.

[0112] Step S2022: Close the second switch K2.

[0113] Step S2023: Control the voltage conversion device 2 to discharge the capacitor at the charging port.

[0114] Step S2031: First disconnect the connection switches K4 and K5 between the charging port 4 and the external charging facility, then disconnect the first switch K1 and the third switch K3, and finally disconnect the connection switches (Kpos+ and Kneg-) between the power battery 1 and the inverter.

[0115] Step S2032: Close the second switch K2.

[0116] Step S2033: Control the voltage conversion device 2 to discharge the capacitor at the charging port.

[0117] Step S204: Check if the voltage of the charging port capacitor reaches the set value. If it does not reach the set value, proceed to step S2023 or step S2033. If it does reach the set value, proceed to step S205.

[0118] It should be noted that after executing steps S2021-S2023 and proceeding to step S204, if the voltage of the charging port capacitor does not reach the set value, proceed to step S2023. Similarly, after executing steps S2031-S2033 and proceeding to step S204, if the voltage of the charging port capacitor does not reach the set value, proceed to step S2033.

[0119] Step S205: Disconnect the second switch K2. After disconnecting K2, the charging gun can be unplugged from the vehicle (unplug the gun) to end the charging process.

[0120] 2. Second charging stop control submodule

[0121] In this embodiment of the invention, the charging stop instruction may also include a first charging stop instruction and a second charging stop instruction. The two charging stop instructions will be described in detail below.

[0122] (1) First charging stop command

[0123] In this embodiment, the second charging stop control submodule can be configured to use... Figure 2 When the power distribution device 3 shown in the diagram has an output voltage level that does not match the charging voltage level, the charging port capacitor is discharged by performing the following operations:

[0124] In response to the received charging stop command, disconnect the connection switch between charging port 4 and the external charging facility. Figure 2 The switches K4 and K5 shown are used to form a conducting loop between the voltage conversion device 2, the power distribution device 3, and the charging port capacitor Cport, and to control the charging port capacitor Cport to discharge through this conducting loop.

[0125] In this embodiment, the inverter's bridge arm in the voltage conversion device 2 can be switched on / off, so that the charging port capacitor Cport forms multiple short-term conduction loops with the lower bridge arm in the inverter. After each conduction loop is formed, the charging port capacitor Cport can be discharged through this conduction loop.

[0126] It should be noted that the control method of the voltage conversion device 2 in this embodiment is the same as the control method of the voltage conversion device 2 adopted by the first charging stop control submodule according to the first charging stop command. For the sake of brevity, it will not be described again here.

[0127] (2) Second charging stop command

[0128] In this embodiment, the second charging stop control submodule can be configured to use... Figure 2 When the power distribution device 3 shown in the diagram has an output voltage level that does not match the charging voltage level, the charging port capacitor can be discharged directly by performing the following operations:

[0129] In response to the received charging stop command, disconnect the connection switch between charging port 4 and the external charging facility. Figure 2 The switches K4 and K5 shown are used to form a conducting loop between the voltage conversion device 2, the power distribution device 3, and the charging port capacitor Cport, and to control the charging port capacitor Cport to discharge through this conducting loop.

[0130] In this embodiment, the inverter's bridge arm in the voltage conversion device 2 can also be controlled to turn on / off, so that the charging port capacitor Cport forms multiple short-term conduction loops with the lower bridge arm in the inverter. After each conduction loop is formed, the charging port capacitor Cport can be discharged through this conduction loop.

[0131] It should be noted that the control method of the voltage conversion device 2 in this embodiment is the same as the control method of the voltage conversion device 2 adopted by the first charging stop control submodule according to the first charging stop command. For the sake of brevity, it will not be described again here.

[0132] Furthermore, in one embodiment, the voltage conversion device 2 may also include the discharge circuit described in the foregoing embodiments, and the discharge circuit will not be described in detail here. In this embodiment, the second charging stop control submodule can be configured to use... Figure 2 When the power distribution device 3 shown above has an output voltage level that does not match the charging voltage level, the above-described discharge circuit is used to discharge the charging port capacitor by performing the following operations:

[0133] In response to the received charging stop command, disconnect the connection switch between charging port 4 and the external charging facility. Figure 2 Switches K4 and K5 (as shown) are then disconnected from the connection switch between the power battery 1 and the inverter. Figure 2 The switches Kpos+ and Kneg- shown finally control the power electronic device Qdischarge to conduct, so that the voltage conversion device 2, the power distribution device 3 and the charging port capacitor Cport form a conducting loop, and control the charging port capacitor Cport to discharge through this conducting loop.

[0134] In this embodiment, each power electronic device in the voltage conversion device 2 is connected in reverse parallel with a diode, such as... Figure 2 As shown, power electronic devices Q1-Q6 and power electronic device Qdischarge are each connected in reverse parallel with a diode. After power electronic device Qdischarge is turned on, the charging port capacitor Cport can not only be connected in parallel with the conducting circuit (parallel branch), but also form a series branch through the diodes in each upper arm of the inverter in voltage conversion device 2, and then be connected in parallel with the DC bus capacitor Cbus of the inverter (series-parallel branch). In other words, the conducting circuit formed after power electronic device Qdischarge is turned on includes the above-mentioned parallel branch and series-parallel branch. The charging port capacitor Cport can discharge not only through the above-mentioned parallel branch, but also through the above-mentioned series-parallel branch, thereby significantly improving the discharge speed of the charging port capacitor Cport.

[0135] The following example uses external charging facilities as charging piles, along with related information. Figure 7 ,right Figure 2 The following further illustrates the discharge control method for the charging port capacitor of the vehicle charging system. In this embodiment, the charging voltage level of the vehicle's internal power battery 1 is 800V, and the output voltage level of the external charging facility is also 400V. (See appendix...) Figure 7 The discharge control method for the charging port capacitor may include the following steps S301-S305:

[0136] Step S301: Detect whether the power battery 1 continues to supply power to the high-voltage system after the 400V charging is completed; if it continues to supply power, proceed to step S303 after executing steps S3021-S3022; if it no longer supplies power, proceed to step S3031-S3032 after executing steps S303.

[0137] Step S3021: Disconnect the connection switches K4 and K5 between the charging port 4 and the external charging facility.

[0138] Step S3022: Control the voltage conversion device 2 to discharge the capacitor at the charging port.

[0139] Step S3031: First disconnect the connection switches K4 and K5 between the charging port 4 and the external charging facility, and then disconnect the connection switches (Kpos+ and Kneg-) between the power battery 1 and the inverter.

[0140] Step S3032: Control the voltage conversion device 2 to discharge the charging port capacitor.

[0141] Step S304: Check if the voltage of the charging port capacitor has reached the set value. If it has not reached the set value, proceed to step S3022 or step S3032. If it has reached the set value, proceed to step S305.

[0142] It should be noted that after executing steps S3021-S3022 and proceeding to step S304, if the voltage of the charging port capacitor does not reach the set value, the process proceeds to step S3032. Similarly, after executing steps S3031-S3032 and proceeding to step S304, if the voltage of the charging port capacitor does not reach the set value, the process proceeds to step S3032.

[0143] Step S305: Disconnect the second switch K2 and the third switch K3. After disconnecting K2 and K3, the charging gun can be unplugged from the vehicle (unplug the gun) to end the charging process.

[0144] The technical solution of the vehicle charging system of the present invention has been described in conjunction with the embodiments shown in the accompanying drawings. The vehicle charging system of the present invention can not only utilize voltage conversion equipment to accommodate charging facilities of different voltage levels on the market, but also pre-charge and discharge the charging port capacitor through a conduction circuit formed by charging control equipment and power distribution equipment, so that the charging facility can be used to charge the vehicle safely and effectively even when the voltage levels of the vehicle and the charging facility are mismatched.

[0145] Furthermore, the present invention also provides a vehicle. In one embodiment of a vehicle according to the present invention, the vehicle may include a power battery and an electric drive system. The electric drive system may include an inverter and a motor. The DC side of the inverter is connected to the power battery, and the AC side of the inverter is connected to the stator winding of the motor. Additionally, the vehicle may include the vehicle charging system described in the aforementioned vehicle charging system embodiment. For ease of explanation, only the parts related to the embodiments of the present invention are shown. For specific technical details not disclosed, please refer to the system section of the embodiments of the present invention.

[0146] Those skilled in the art will understand that all or part of the processes in the system implementing the above-described embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable storage medium can include any entity or device capable of carrying the computer program code, a medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer-readable storage medium can be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0147] Furthermore, it should be understood that since the various modules are only provided to illustrate the functional units of the device of the present invention, the physical devices corresponding to these modules may be the processor itself, or a part of the processor's software, hardware, or a combination of software and hardware. Therefore, the number of modules shown in the figures is merely illustrative.

[0148] Those skilled in the art will understand that the various modules in the device can be adaptively split or combined. Such splitting or combining of specific modules will not cause the technical solution to deviate from the principles of the present invention; therefore, the technical solutions after splitting or combining will fall within the protection scope of the present invention.

[0149] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A vehicle charging system, the vehicle comprising a power battery and an electric drive system, the electric drive system comprising an inverter and an electric motor, the DC side of the inverter being connected to the power battery, the AC side of the inverter being connected to the stator winding of the electric motor, the charging system comprising a voltage conversion device, the voltage conversion device comprising the inverter, the stator winding, a first positive terminal, a second positive terminal, and a negative terminal, the first positive terminal and the negative terminal being respectively connected to the positive and negative terminals of the DC side, and the second positive terminal being connected to the center tap of the stator winding. Its features are, The charging system also includes a charging port capacitor, a power distribution device, and a charging control device, wherein the power distribution device is connected to the voltage conversion device and the charging port capacitor respectively; The charging control device is configured to: In response to the received charging start command, the system controls the power battery, the voltage conversion device, the power distribution device, and the charging port capacitor to form a conducting circuit, and controls the power battery to precharge the charging port capacitor through the conducting circuit; In response to a received charging stop command, the voltage conversion device, the power distribution device, and the charging port capacitor are controlled to form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop.

2. The vehicle charging system according to claim 1, characterized in that, The charging system also includes a charging port, which includes a positive input terminal and a negative input terminal; The power distribution equipment includes a first switch, a second switch, and a third switch; the first end and the second end of the first switch are respectively connected to the first positive terminal and the positive input terminal; the first end and the second end of the second switch are respectively connected to the second positive terminal and the positive input terminal; and the first end and the second end of the third switch are respectively connected to the negative terminal and the negative input terminal. The first and second ends of the charging port capacitor are respectively connected to the second end of the second switch and the first end of the third switch.

3. The vehicle charging system according to claim 2, characterized in that, The charging control device includes a charging start control module, which includes a capacitor pre-charge sub-module. The capacitor pre-charge submodule is configured to pre-charge the charging port capacitor by performing the following operations: In response to the received charging start command, the second switch is closed and the first switch and the third switch are kept in the open state, so that the power battery, the voltage conversion device, the second switch and the charging port capacitor form a conducting circuit; The voltage conversion device is controlled to step down the electrical energy output from the power battery, and the stepped-down electrical energy is transmitted to the charging port capacitor through the conduction circuit for pre-charging. Pre-charging stops when the voltage of the charging port capacitor reaches a set value.

4. The vehicle charging system according to claim 3, characterized in that, The charging start control module also includes a first power battery charging sub-module; The first power battery charging submodule is configured to charge the power battery by performing the following operations when the output voltage level of the external charging facility connected to the charging port matches the charging voltage level of the power battery: After the pre-charging submodule stops pre-charging, the second switch is disconnected, then the first switch and the third switch are closed, and finally the connection switch between the charging port and the external charging facility is closed, so that the power battery, the voltage conversion device, the power distribution device, the charging port and the external charging facility form a charging circuit, and the external charging facility is controlled to charge the power battery through the charging circuit; And / or, The charging start control module also includes a second power battery charging sub-module; The second power battery charging submodule is configured to charge the power battery by performing the following operations when the output voltage level of the external charging facility connected to the charging port does not match the charging voltage level of the power battery: After the pre-charging submodule stops pre-charging, the second switch is disconnected, then the third switch is closed, and finally the connection switch between the charging port and the external charging facility is closed, so that the power battery, the voltage conversion device, the power distribution device, the charging port and the external charging facility form a charging circuit, and the external charging facility is controlled to charge the power battery through the charging circuit.

5. The vehicle charging system according to claim 4, characterized in that, The charging control device includes a charging stop control module, and the charging stop control module includes a first charging stop control submodule. The first charging stop control submodule is configured to discharge the charging port capacitor by performing the following operations when the output voltage level matches the charging voltage level: In response to the received charging stop command, the connection switch between the charging port and the external charging facility is disconnected, then the first switch and the third switch are disconnected, and finally the second switch is closed to make the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop; The charging stop command is a command to stop charging the power battery and, after stopping charging, to control the power battery to continue supplying power to the high-voltage system inside the vehicle.

6. The vehicle charging system according to claim 4, characterized in that, The charging control device includes a charging stop control module, and the charging stop control module includes a second charging stop control submodule; The second charging stop control submodule is configured to discharge the charging port capacitor by performing the following operations when the output voltage level does not match the charging voltage level: In response to a received charging stop command, the connection switch between the charging port and the external charging facility is disconnected, so that the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop; The charging stop command is either an instruction to stop charging the power battery and, after stopping charging, to control the power battery to continue supplying power to the high-voltage system inside the vehicle, or an instruction to stop charging the power battery and, after stopping charging, to control the power battery to no longer supply power to the high-voltage system inside the vehicle.

7. The vehicle charging system according to claim 5 or 6, characterized in that, The voltage conversion device further includes a discharge circuit connected in parallel with the DC side of the inverter. The discharge circuit includes a power electronic device and a resistor. The first main electrode of the power electronic device is connected to the positive terminal of the DC side, the second main electrode of the power electronic device is connected to the first end of the resistor, and the second end of the resistor is connected to the negative terminal of the DC side.

8. The vehicle charging system according to claim 7, characterized in that, When the charging stop command is an instruction to stop charging the power battery and, after charging stops, control the power battery to no longer supply power to the high-voltage system in the vehicle, the first charging stop control submodule is further configured to discharge the charging port capacitor by performing the following operations when the output voltage level matches the charging voltage level: In response to the received charging stop command, the connection switch is disconnected, then the first switch and the third switch are disconnected, the connection switch between the power battery and the inverter is disconnected, the second switch is closed, and finally the power electronic device is turned on so that the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop.

9. The vehicle charging system according to claim 7, characterized in that, When the charging stop command is an instruction to stop charging the power battery and, after charging stops, control the power battery to no longer supply power to the high-voltage system in the vehicle, the second charging stop control submodule is further configured to discharge the charging port capacitor by performing the following operations when the output voltage level does not match the charging voltage level: In response to the received charging stop command, the connection switch is disconnected, then the connection switch between the power battery and the inverter is disconnected, and finally the power electronic device is turned on so that the voltage conversion device, the power distribution device and the charging port capacitor form a conducting loop, and the charging port capacitor is controlled to discharge through the conducting loop.

10. A vehicle comprising a power battery and an electric drive system, the electric drive system comprising an inverter and an electric motor, the DC side of the inverter being connected to the power battery, and the AC side of the inverter being connected to the stator winding of the electric motor, characterized in that, The vehicle also includes the vehicle charging system according to any one of claims 1 to 9.

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