Vehicle-mounted charging system, control method thereof and electric vehicle

Abstract

The invention provides a vehicle-mounted charging system, a control method thereof and an electric vehicle. The vehicle-mounted charging system comprises a first power conversion module, a second power conversion module, a switch module and a control module. And the control module is used for controlling the switch module, so that the first power conversion module is directly connected with the power battery, or the first power conversion module is connected with the power battery through the second power conversion module. By adopting the vehicle-mounted charging system, the loss of electric energy in the vehicle-mounted charging system can be reduced, so that the utilization rate of the electric energy can be improved.

Description

Technical Field

[0001] This application relates to the technical field of electric vehicle charging, and particularly to an in-vehicle charging system, a control method thereof, and an electric vehicle. Background Art

[0002] With the continuous development of photovoltaic power generation technology and the gradual popularization of electric vehicles, the application of photovoltaic power generation technology in electric vehicles has become a new trend. By adding an in-vehicle photovoltaic charging system to an electric vehicle to supply power to the power battery of the electric vehicle, the driving range of the electric vehicle can be effectively increased.

[0003] The existing in-vehicle photovoltaic charging system mainly consists of an inverter, a charging control circuit, and an MPPT (Maximum PowerPoint Tracking) circuit. The electric energy output by the solar panel can only charge the power battery of the electric vehicle after being processed by the inverter, the charging control circuit, and the MPPT circuit. In this in-vehicle charging system, the transmission path of electric energy is long, and there is a problem of large electric energy loss. Therefore, how to reduce the electric energy loss in the in-vehicle charging system has become one of the technical problems to be solved urgently. Summary of the Invention

[0004] The embodiments of this application provide an in-vehicle charging system, a control method thereof, and an electric vehicle, which reduce the electric energy loss in the in-vehicle charging system and improve the utilization rate of electric energy.

[0005] In a first aspect, the embodiments of this application provide an in-vehicle charging system. The in-vehicle charging system includes a first power conversion module, a second power conversion module, a switch module, and a control module. The control module is respectively connected to the first power conversion module, the second power conversion module, and the switch module. The switch module is also respectively connected to the first power conversion module and the power battery. The first power conversion module is further connected to the second power conversion module, and the second power conversion module is further connected to the power battery. The control module is used to control the switch module so that the first power conversion module is directly connected to the power battery, or the first power conversion module is connected to the power battery through the second power conversion module.

[0006] In the embodiments of this application, the in-vehicle charging system can control through the control module whether the electric energy output by the first power conversion module directly charges the power battery or is first processed by the second power conversion module and then charges the power battery, that is, it can control whether to use the second power conversion module to charge the power battery in the in-vehicle charging system. In this way, the electric energy loss in the in-vehicle charging system can be reduced, and further the electric energy utilization rate of the in-vehicle charging system can be improved.

[0007] In combination with the first aspect, in a feasible implementation manner, the first power conversion module is configured to convert the received first current into a first direct current and output it. When the first power conversion module is connected to the power battery through the second power conversion module, the second power conversion module is configured to convert the first direct current from the first power conversion module into a second direct current and charge the power battery with the second direct current.

[0008] In combination with the first aspect, in a feasible implementation manner, the control module is further configured to: obtain the first port voltage of the first power conversion module and the voltage of the power battery, and determine a target voltage difference according to the first port voltage and the voltage of the power battery, where the first port voltage is the voltage of the port of the first power conversion module for connecting to the switch module. If it is determined that the target voltage difference is within a preset voltage range, control the switch module so that the first power conversion module is directly connected to the power battery. If it is determined that the target voltage difference is not within the preset voltage range, control the switch module so that the first power conversion module is connected to the power battery through the second power conversion module.

[0009] In combination with the first aspect, in a feasible implementation manner, the switch module includes a first controllable switch and a second controllable switch. The first port of the first power conversion module is connected to the first end of the power battery through the first controllable switch, and the second port of the first power conversion module is connected to the second end of the power battery through the second controllable switch. The control module is respectively connected to the first controllable switch and the second controllable switch.

[0010] In combination with the first aspect, in a feasible implementation manner, the switch module further includes a third controllable switch and a fourth controllable switch. The first port of the first power conversion module is further connected to the first port of the second power conversion module through the third controllable switch, and the second port of the first power conversion module is further connected to the second port of the second power conversion module through the fourth controllable switch. The control module is respectively connected to the third controllable switch and the fourth controllable switch.

[0011] In combination with the first aspect, in a feasible implementation manner, the control module is configured to: if it is determined that the target voltage difference is within the preset voltage range, control the first controllable switch and the second controllable switch to conduct, and control the second power conversion module to disconnect, so that the first power conversion module is directly connected to the power battery. If it is determined that the target voltage difference is not within the preset voltage range, control the first controllable switch and the second controllable switch to turn off, and control the second power conversion module to conduct, so that the first power conversion module is connected to the power battery through the second power conversion module.

[0012] In combination with the first aspect, in a feasible implementation manner, the control module is configured to: if it is determined that the target voltage difference is within the preset voltage range, control the first controllable switch and the second controllable switch to conduct, and control the third controllable switch and the fourth controllable switch to turn off, so that the first power conversion module is directly connected to the power battery. If it is determined that the target voltage difference is not within the preset voltage range, control the first controllable switch and the second controllable switch to turn off, and control the third controllable switch and the fourth controllable switch to conduct, so that the first power conversion module is connected to the power battery through the second power conversion module.

[0013] In combination with the first aspect, in a feasible implementation manner, the second power conversion module includes at least a first phase arm and a second phase arm. The control module is respectively connected to the first controllable switch and the second controllable switch. The first port of the first power conversion module is connected to the first end of the power battery through the first controllable switch, and the second port of the first power conversion module is connected to the second end of the power battery through the second controllable switch. The first port of the first power conversion module is also respectively connected to the first end of the first phase arm and the first end of the second phase arm, and the second port of the first power conversion module is also respectively connected to the second end of the first phase arm and the second end of the second phase arm.

[0014] In combination with the first aspect, in a feasible implementation manner, the control module is further configured to: if it is determined that the target voltage difference is within the preset voltage range, control the first controllable switch and the second controllable switch to conduct, and control the switching tubes included in the first phase arm and the second phase arm to turn off, so that the first power conversion module is directly connected to the power battery. If it is determined that the target voltage difference is not within the preset voltage range, control the first controllable switch and the second controllable switch to turn off, and control the switching tubes included in the first phase arm and the second phase arm to conduct, so that the first power conversion module is connected to the power battery through the second power conversion module.

[0015] In combination with the first aspect, in a feasible implementation manner, the on-vehicle charging system further includes a selection switch. A first end of the selection switch is connected to an AC interface of the on-vehicle charging system, a second end of the selection switch is connected to an external DC power supply, and a third end of the selection switch is connected to the first power module.

[0016] In combination with the first aspect, in a feasible implementation manner, when the first end is connected to the third end, the first current includes a first alternating current provided by the AC interface, and the control module is further configured to control the switch module so that the first power conversion module is connected to the power battery through the second power conversion module. When the second end is connected to the third end, the first current includes a third direct current provided by the external DC power supply, and the control module is further configured to control the switch module so that the first power conversion module is directly connected to the power battery, or the first power conversion module is connected to the power battery through the second power conversion module.

[0017] In combination with the first aspect, in a feasible implementation manner, when the first power conversion module is directly connected to the power battery, the power battery is charged by the first direct current.

[0018] In combination with the first aspect, in a feasible implementation manner, the control module is further connected to the power battery. The control module is further configured to: if it is determined that the voltage of the first port is less than a preset voltage threshold, control the switch module so that the first power conversion module is connected to the power battery through the second power conversion module, and control the power battery to charge the bus capacitor of the first power conversion module. If it is determined that the voltage of the first port is greater than or equal to the preset voltage threshold, control the switch module so that the first power conversion module is directly connected to the power battery.

[0019] In combination with the first aspect, in a feasible implementation manner, the external DC power supply includes a photovoltaic module.

[0020] Second aspect, an embodiment of the present application provides a control method for an in-vehicle charging system, which is applicable to a control module in the in-vehicle charging system. The method includes: obtaining a first port voltage of a first power conversion module and a voltage of a power battery, where the first port voltage is the voltage of the port of the first power conversion module for connecting to the switch module. Controlling the switch module according to the first port voltage and the voltage of the power battery, so that the first power conversion module is directly connected to the power battery, or the first power conversion module is connected to the power battery through a second power conversion module.

[0021] In combination with the second aspect, in a feasible implementation manner, the in-vehicle charging system further includes a first power conversion module, a second power conversion module, and a switch module. The control module is respectively connected to the first power conversion module, the second power conversion module, and the switch module. The switch module is also respectively connected to the first power conversion module and the power battery. The first power conversion module is further connected to the second power conversion module. The second power conversion module is further connected to the power battery.

[0022] In combination with the second aspect, in a feasible implementation manner, the first power conversion module is configured to convert a received first current into a first direct current and output it. And, when the first power conversion module is connected to the power battery through the switch module and the second power conversion module, the second power conversion module is configured to convert the first direct current from the first power conversion module into a second direct current and charge the power battery with the second direct current.

[0023] In combination with the second aspect, in a feasible implementation manner, the controlling the switch module according to the first port voltage and the voltage of the power battery includes: determining a target voltage difference according to the first port voltage and the voltage of the power battery. If it is determined that the target voltage difference is within a preset voltage range, then control the switch module so that the first power conversion module is directly connected to the power battery. If it is determined that the target voltage difference is not within the preset voltage range, then control the switch module so that the first power conversion module is connected to the power battery through the second power conversion module.

[0024] In combination with the second aspect, in a feasible implementation manner, the switching module includes a first controllable switch and a second controllable switch. A first port of the first power conversion module is connected to a first end of the power battery through the first controllable switch, and a second port of the first power conversion module is connected to a second end of the power battery through the second controllable switch. The control module is respectively connected to the first controllable switch and the second controllable switch. Controlling the switching module to directly connect the first power conversion module to the power battery includes: controlling the first controllable switch and the second controllable switch to conduct, and controlling the second power conversion module to disconnect, so that the first power conversion module is directly connected to the power battery.

[0025] In combination with the second aspect, in a feasible implementation manner, controlling the switching module to connect the first power conversion module to the power battery through the second power conversion module includes: controlling the first controllable switch and the second controllable switch to turn off, and controlling the second power conversion module to conduct, so that the first power conversion module is connected to the power battery through the second power conversion module.

[0026] In combination with the second aspect, in a feasible implementation manner, the switching module further includes a third controllable switch and a fourth controllable switch. A first port of the first power conversion module is further connected to a first port of the second power conversion module through the third controllable switch, and a second port of the first power conversion module is further connected to a second port of the second power conversion module through the fourth controllable switch. The control module is respectively connected to the third controllable switch and the fourth controllable switch. Controlling the switching module to directly connect the first power conversion module to the power battery includes: controlling the first controllable switch and the second controllable switch to conduct, and controlling the third controllable switch and the fourth controllable switch to turn off, so that the first power conversion module is directly connected to the power battery.

[0027] In combination with the second aspect, in a feasible implementation manner, controlling the switching module to connect the first power conversion module to the power battery through the second power conversion module includes: controlling the first controllable switch and the second controllable switch to turn off, and controlling the third controllable switch and the fourth controllable switch to conduct, so that the first power conversion module is connected to the power battery through the second power conversion module.

[0028] Combined with the second aspect, in a feasible implementation manner, the second power conversion module at least includes a first phase bridge arm and a second phase bridge arm. The control module is respectively connected to the first controllable switch and the second controllable switch. The first port of the first power conversion module is connected to the first end of the power battery through the first controllable switch, and the second port of the first power conversion module is connected to the second end of the power battery through the second controllable switch. The first port of the first power conversion module is also respectively connected to the first end of the first phase bridge arm and the first end of the second phase bridge arm, and the second port of the first power conversion module is also respectively connected to the second end of the first phase bridge arm and the second end of the second phase bridge arm. Controlling the switch module to directly connect the first power conversion module to the power battery includes: controlling the first controllable switch and the second controllable switch to conduct, and controlling the switching tubes included in the first phase bridge arm and the second phase bridge arm to turn off, so that the first power conversion module is directly connected to the power battery.

[0029] Combined with the second aspect, in a feasible implementation manner, controlling the switch module to connect the first power conversion module to the power battery through the second power conversion module includes: controlling the first controllable switch and the second controllable switch to turn off, and controlling the switching tubes included in the first phase bridge arm and the second phase bridge arm to conduct, so that the first power conversion module is connected to the power battery through the second power conversion module.

[0030] Combined with the second aspect, in a feasible implementation manner, the on-vehicle charging system further includes a selection switch. The first end of the selection switch is connected to the AC interface of the on-vehicle charging system, the second end of the selection switch is connected to an external DC power supply, and the third end of the selection switch is connected to the first power module. The method further includes: if it is determined that the first end is connected to the third end, controlling the switch module so that the first power conversion module is connected to the power battery through the second power conversion module. If it is determined that the second end is connected to the third end, perform the step of obtaining the voltage of the first port of the first power conversion module and the voltage of the power battery.

[0031] In combination with the second aspect, in a feasible implementation manner, before obtaining the voltage of the first port of the first power conversion module and the voltage of the second port of the second power conversion module, the method further includes: if it is determined that the voltage of the first port is less than a preset voltage threshold, controlling the switch module so that the first power conversion module is connected to the power battery through the second power conversion module, and controlling the power battery to charge the bus capacitor of the first power conversion module. If it is determined that the voltage of the first port is greater than or equal to the preset voltage threshold, controlling the switch module so that the first power conversion module is directly connected to the power battery.

[0032] In combination with the second aspect, in a feasible implementation manner, the external DC power supply includes a photovoltaic module.

[0033] In a third aspect, an embodiment of the present application provides an electric vehicle, and the vehicle includes the on-vehicle charging system described in the first aspect above.

[0034] By implementing the embodiments of the present invention, the on-vehicle charging system can be controlled by the control module to make the electric energy output by the first power conversion module directly charge the power battery, or first be processed by the second power conversion module and then charge the power battery, that is, it can be controlled whether to use the second power conversion module in the on-vehicle charging system to charge the power battery, so as to reduce the power loss in the on-vehicle charging system, and further improve the power utilization rate of the on-vehicle charging system. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. 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 be obtained according to these drawings.

[0036] Figure 1 is a schematic structural diagram of an on-vehicle charging system provided by an embodiment of the present application;

[0037] Figure 2 is a schematic structural diagram of another on-vehicle charging system provided by an embodiment of the present application;

[0038] Figure 3 is a schematic structural diagram of another on-vehicle charging system provided by an embodiment of the present application;

[0039] Figure 4 is a schematic structural diagram of another on-vehicle charging system provided by an embodiment of the present application

[0040] Figure 5It is a schematic structural diagram of another in-vehicle charging system provided by an embodiment of the present application;

[0041] Figure 6 It is a schematic structural diagram of another in-vehicle charging system provided by an embodiment of the present application;

[0042] Figure 7 It is a schematic structural diagram of another in-vehicle charging system provided by an embodiment of the present application;

[0043] Figure 8 It is a schematic structural diagram of another in-vehicle charging system provided by an embodiment of the present application;

[0044] Figure 9 It is a schematic flowchart of a control method for an in-vehicle charging system provided by an embodiment of the present application;

[0045] Figure 10 It is a schematic flowchart of another control method for an in-vehicle charging system provided by an embodiment of the present application;

[0046] Figure 11 It is a schematic flowchart of another control method for an in-vehicle charging system provided by an embodiment of the present application;

[0047] Figure 12 It is a schematic structural diagram of a vehicle provided by an embodiment of the present application. Detailed implementation manners

[0048] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.

[0049] In the existing in-vehicle photovoltaic charging system for electric vehicles, the electric energy output by the solar panel usually needs to go through two-stage power conversion before it can charge the battery to be charged, resulting in problems of power loss and low power utilization rate in this process. Therefore, the technical problem to be solved by the present application is: how to reduce the power loss in the in-vehicle charging system.

[0050] Please refer to Figure 1 , Figure 1 It is a schematic structural diagram of an in-vehicle charging system provided by an embodiment of the present application. Optionally, the in-vehicle charging system can be applied to an electric vehicle. As Figure 1 shown, the in-vehicle charging system 10 may include a first power conversion module 11, a second power conversion module 12, a switch module 13, and a control module 14. The control module 14 can be respectively connected to the first power conversion module 11, the second power conversion module 12, and the switch module 13. The switch module 13 can be respectively connected to the first power conversion module 11 and the power battery 20. The second power conversion module 12 can also be connected to the power battery 20.

[0051] In actual work, the control module 14 can be used to control the switch module 13 so that the first power conversion module 11 is directly connected to the power battery 20, or the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0052] It should be noted that the direct connection between the first power conversion module 11 and the power battery 20 means that the first power conversion module 11 is connected to the power battery 20 without passing through the buck-boost module, that is, the second power conversion module 12. For example, the first power conversion module 11 and the power battery 20 can be connected only through a switch.

[0053] It should be supplemented that, please continue to refer to Figure 1 , Figure 1 The dashed line in indicates that the first power conversion module 11 can be directly connected to the second power conversion module 12. Alternatively, the first power conversion module 11 can also be connected to the second power conversion module 12 through the switch module 13, and the embodiments of the present application do not make specific limitations on this. That is to say, the switch module 13 can be not connected to the second power conversion module 12, or the switch module 13 can be connected to the second power conversion module 12.

[0054] It should be understood that when the first power conversion module 11 is connected to the second power conversion module 12 through the switch module 13, the control module 14 can be used to control the switch module 13 to short-circuit or make the second power conversion module 12 in a conducting state.

[0055] It also should be noted that the second power conversion module 12 can have a buck function or a boost function. When the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12, the second power conversion module 12 can first step down and then step up the input first direct current, or first step up and then step down the input first direct current, or only step up or only step down the input first direct current to obtain and output a second direct current. Specifically, the second power conversion module 12 can control the buck-boost of the input current according to a preset control strategy, and the embodiments of the present application do not make specific limitations on this control strategy.

[0056] In the embodiments of the present application, the on-vehicle charging system 10 can control through the control module 14 whether the electric energy output by the first power conversion module 11 directly charges the power battery 20 or first passes through the processing of the second power conversion module 12 and then charges the power battery 20, that is, it can control whether to use the second power conversion module 12 in the on-vehicle charging system 10 to charge the power battery 20, so as to reduce the power loss in the charging process of the on-vehicle charging system 10, and further improve the power utilization rate of the on-vehicle charging system 10.

[0057] In an alternative embodiment, the first power conversion module 11 can be configured to convert the received first current into a first direct current and output it. When the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12, the second power conversion module 12 can be configured to convert the first direct current from the first power conversion module 11 into a second direct current and charge the power battery 20 with the second direct current. Here, the voltage value corresponding to the first direct current can be greater than the voltage value corresponding to the second direct current, or the voltage value corresponding to the first direct current can be less than the voltage value corresponding to the second direct current.

[0058] It should be noted that the above-mentioned first current can include a first alternating current or a third direct current. When the first current is a first alternating current, the first power conversion module 11 can be configured to perform rectification and boost DC-DC conversion. When the first current is a third direct current, the first power conversion module 11 can be configured to perform boost DC-DC conversion.

[0059] In an alternative embodiment, when the on-vehicle charging system 10 is directly connected between the first power conversion module 11 and the power battery 20, the power battery 20 can be charged with the first direct current. In this case, the electric energy does not need to be processed by the second power conversion module 12, avoiding the power loss caused by the second power conversion module 12, thereby improving the power utilization rate of the on-vehicle charging system 10.

[0060] In an alternative embodiment, the control module 14 can also be configured to obtain the first port voltage of the first power conversion module 11 and the voltage of the power battery 20, and determine a target voltage difference according to the first port voltage and the voltage of the power battery 20. The control module 14 can also be configured to, if it determines that the target voltage difference is within a preset voltage range, control the switch module 13 to directly connect the first power conversion module 11 and the power battery 20. The control module 14 can also be configured to, if it determines that the target voltage difference is not within the preset voltage range, control the switch module 13 to connect the first power conversion module 11 to the power battery 20 through the second power conversion module 12.

[0061] Among them, the preset voltage range can be an empirical value. Moreover, the preset voltage range can be the factory default of the on-vehicle charging system or can be temporarily configured by the administrator.

[0062] It should be noted that during the process of the on-vehicle charging system 10 charging the power battery 20 through the AC interface or an external DC power supply, the first port voltage of the first power conversion module 11 is also the output voltage of the first power conversion module 11.

[0063] It should also be noted that the voltage of the power battery 20 is also the voltage of the second port of the second power conversion module 12, which can also be said to be the output voltage of the second power conversion module 12.

[0064] Among them, the first port voltage of the first power conversion module 11 can be the voltage of the port of the first power conversion module 11 used to connect to the switch module 13, and the second port voltage of the second power conversion module 12 can be the voltage of the port of the second power conversion module 12 used to connect to the power battery 20. For example, please refer to Figure 2 , Figure 2 which is a schematic structural diagram of another on-vehicle charging system provided by an embodiment of the present application. As Figure 2 shown, the control module 14 can be respectively connected to the first port and the second port of the first power conversion module 11 to obtain the first port voltage of the first power conversion module 11, that is, the voltage between the first port and the second port of the first power conversion module 11. The control module 14 can also be respectively connected to the third port and the fourth port of the second power conversion module 12 to obtain the second port voltage of the second power conversion module 12, that is, the voltage between the third port and the fourth port of the second power conversion module 12.

[0065] Optionally, the control module 14 can include a first voltage collector and a second voltage collector. The control module 14 can obtain the first port voltage of the first power conversion module 11 through the first voltage collector, and the control module 14 can obtain the second port voltage of the second power conversion module 12 through the second voltage collector. It should be noted that the first voltage collector and the second voltage collector can be different voltage collectors or the same voltage collector, and the embodiments of the present application do not make specific limitations on this.

[0066] Please continue to refer to Figure 2 , the on-vehicle charging system can also include a bus capacitor 15 of the first power conversion module 11. It should be noted that the first port voltage of the first power conversion module 11 can also be the voltage of the bus capacitor 15 of the first power conversion module.

[0067] In an optional implementation manner, please refer to Figure 3 , Figure 3 which is a schematic structural diagram of another on-vehicle charging system provided by an embodiment of the present application. As Figure 3 shown, the switch module 13 can include a first controllable switch 131 and a second controllable switch 132. The first port of the first power conversion module 11 can be connected to the first end of the power battery 20 through the first controllable switch 131, and the second port of the first power conversion module 11 can be connected to the second end of the power battery 20 through the second controllable switch 132. The control module 14 can be respectively connected to the first controllable switch 131 and the second controllable switch 132.

[0068] In actual work, the control module 14 can also be used to control the first controllable switch 131 and the second controllable switch 132 to conduct if it is determined that the target voltage value is within the preset voltage range, and control the second power conversion module 12 to disconnect, so that the first power conversion module 11 is directly connected to the power battery 20. The control module 14 can also be used to control the first controllable switch 131 and the second controllable switch 132 to turn off if it is determined that the target voltage value is not within the preset voltage range, and control the second power conversion module 12 to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0069] In an alternative embodiment, please refer to Figure 4 , Figure 4 is a schematic structural diagram of another on-vehicle charging system provided by an embodiment of the present application. As Figure 4 shown, the switch module 13 may further include a third controllable switch 133 and a fourth controllable switch 134. The control module 14 may also be respectively connected to the third controllable switch 133 and the fourth controllable switch 134. The first port of the first power conversion module 11 may also be connected to the first port of the second power conversion module 12 through the third controllable switch 133, and the second port of the first power conversion module 11 may also be connected to the second port of the second power conversion module 12 through the fourth controllable switch 134.

[0070] In actual work, the control module 14 can also be used to control the first controllable switch 131 and the second controllable switch 132 to conduct if it is determined that the target voltage value is within the preset voltage range, and control the third controllable switch 133 and the fourth controllable switch 134 to turn off, so that the first power conversion module 11 is directly connected to the power battery 20. The control module 14 can also be used to control the first controllable switch 131 and the second controllable switch 132 to turn off if it is determined that the target voltage value is not within the preset voltage range, and control the third controllable switch 133 and the fourth controllable switch 134 to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0071] In the above implementation, the on-vehicle charging system 10 can control whether to use the second power conversion module 12 to charge the power battery 20 in the on-vehicle charging system 10 through the switch module 13 including the first controllable switch 131, the second controllable switch 132, the third controllable switch 133, and the fourth controllable switch 134. With the switch module 13 having the above structure, its structure is simple and easy to implement, the design and production cost of the switch module 13 can be low, which is beneficial to reducing the cost of the on-vehicle charging system 10.

[0072] In an alternative embodiment, please refer to Figure 5 ,Figure 5 This is a schematic structural diagram of another in-vehicle charging system provided by an embodiment of the present application. As Figure 5 shown, the second power conversion module 12 may at least include a first phase bridge arm 121 and a second phase bridge arm 122. The control module 14 may be respectively connected to the first controllable switch 131 and the second controllable switch 132. The first port of the first power conversion module 11 may also be respectively connected to the first end of the first phase bridge arm 121 and the first end of the second phase bridge arm 122. The second port of the first power conversion module 11 may also be respectively connected to the second end of the first phase bridge arm 121 and the second end of the second phase bridge arm 122.

[0073] In actual operation, the control module 14 may also be used to control the first controllable switch 131 and the second controllable switch 132 to conduct if it is determined that the target voltage value is within the preset voltage range, and control the switching tubes included in the first phase bridge arm 121 and the second phase bridge arm 122 to turn off, so that the first power conversion module 11 is directly connected to the power battery 20. The control module 14 may also be used to control the first controllable switch 131 and the second controllable switch 132 to turn off if it is determined that the target voltage value is not within the preset voltage range, and control the switching tubes included in the first phase bridge arm 121, the second phase bridge arm 122, the third phase bridge arm and the fourth phase bridge arm to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0074] Optionally, the second power conversion module 12 may further include a third phase bridge arm and a fourth phase bridge arm. The first end of the third phase bridge arm and the first end of the fourth phase bridge arm may be connected to the first end of the power battery 20. The second end of the third phase bridge arm and the second end of the fourth phase bridge arm may be connected to the second end of the power battery 20.

[0075] Specifically, the control module 14 may also be used to control the first controllable switch 131 and the second controllable switch 132 to conduct if it is determined that the target voltage value is within the preset voltage range, and control the switching tubes included in the first phase bridge arm 121, the second phase bridge arm 122, the third phase bridge arm and the fourth phase bridge arm to turn off, so that the first power conversion module 11 is directly connected to the power battery 20. The control module 14 may also be used to control the first controllable switch 131 and the second controllable switch 132 to turn off if it is determined that the target voltage value is not within the preset voltage range, and control the switching tubes included in the first phase bridge arm 121, the second phase bridge arm 122, the third phase bridge arm and the fourth phase bridge arm to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0076] In the above implementation, the on-vehicle charging system 10 can control whether to use the second power conversion module 12 to charge the power battery 20 in the on-vehicle charging system 10 through the switch module 13 including the first controllable switch 131 and the second controllable switch 132, and in combination with the switching tubes included in the second power conversion module 12. The switch module 13 with the above structure is simple in structure and easy to implement, can make the design and production cost of the switch module 13 low, and is beneficial to reducing the cost of the on-vehicle charging system 10.

[0077] In the embodiments of the present application, the first controllable switch 131, the second controllable switch 132, the third controllable switch 133, and the fourth controllable switch 134 can specifically be mechanical switches, controllable switching tubes, or other forms of electronic devices that can be controlled by the control module 14 to conduct or turn off. The present application does not limit the specific type of the controllable switch. Exemplarily, the controllable switching tube can be a turn-off thyristor, a power transistor, a power field effect transistor, etc.

[0078] In an alternative embodiment, please refer to Figure 6 , Figure 6 which is a schematic structural diagram of another on-vehicle charging system provided by the embodiments of the present application. As Figure 6 shown, the on-vehicle charging system 10 may further include a selection switch 16. The first end of the selection switch 16 can be connected to the AC power interface 30, the second end of the selection switch 16 can be connected to the external DC power source 40, and the third end of the selection switch 16 can be connected to the first power conversion module 11.

[0079] In actual operation, when the first end and the third end of the selection switch 16 are connected, the first current may include the first alternating current provided by the AC power interface 30, and the control module 14 can also be used to control the switch module 13 so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12. When the second end and the third end of the selection switch 16 are connected, the first current may include the third direct current provided by the external DC power source 40, and the control module 14 can also be used to control the switch module 13 so that the first power conversion module 11 is directly connected to the power battery 20, or the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0080] It should be understood that when the on-vehicle charging system 10 charges the power battery 20 through the AC power interface 30, the first current input to the first power conversion module 11 can be the first alternating current. When the on-vehicle charging system 10 charges the power battery 20 through the external DC power source 40, the first current input to the first power conversion module 11 can be the third direct current.

[0081] Optionally, the control module 14 can obtain the user's selection instruction and further control the port connection of the gating switch 16 according to the selection instruction, so as to realize charging the power battery 20 using the AC power interface 30 or the external DC power supply 40. Alternatively, when the control module 14 detects an abnormality in the external DC power supply 40, it can also switch to using the AC power interface 30 to charge the power battery 20 through the gating switch 16.

[0082] The above two methods are only exemplary ways for the control module 14 to control the gating switch 16. In specific implementation manners, there may be other ways to control the gating switch 16, and the embodiments of the present application do not make specific limitations thereon.

[0083] Optionally, the gating switch 16 can specifically be a mechanical switch controllable by the control module 14, such as a relay, a single-pole double-throw switch, etc. The embodiments of the present application do not limit the specific type of the gating switch 16.

[0084] Among them, the external DC power supply 40 can include any form of power supply that can output direct current, such as a photovoltaic module, a wind energy device, etc. The embodiments of the present application do not make specific limitations on the implementation form of the external DC power supply 40.

[0085] In an optional implementation manner, please refer to Figure 7 , Figure 7 which is a schematic structural diagram of another in-vehicle charging system provided by the embodiments of the present application. As Figure 7 shown, the control module 14 can also be connected to the power battery 20.

[0086] In actual operation, when the second end and the third end of the gating switch 16 are connected, that is, when the in-vehicle charging system 10 uses the external DC power supply 40 to charge the power battery, the control module 14 can also be used to control the switch module 13 if it is determined that the voltage of the first port is less than the preset voltage threshold, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12, and control the power battery 20 to charge the bus capacitor 15 of the first power conversion module 11 to the above preset voltage threshold. The control module 14 can also be used to control the switch module 13 if it is determined that the voltage of the first port is greater than or equal to the preset voltage threshold, so that the first power conversion module 11 is directly connected to the power battery 20.

[0087] Among them, the preset voltage threshold can be an empirical value. And this preset voltage threshold can be the factory default of the in-vehicle charging system 10, or can be temporarily configured by the management personnel. Exemplarily, this preset voltage threshold can be 300V.

[0088] In the above implementation, when the in-vehicle charging system 10 charges the power battery using the external DC power supply 40, it can first determine whether the voltage of the bus capacitor 15 of the first power conversion module 11 is greater than or equal to a preset voltage threshold. If the in-vehicle charging system 10 determines that the voltage of the bus capacitor 15 is less than the preset voltage threshold, it can first control the switch module 13 to enable the power battery 20 to charge the bus capacitor 15. After the voltage of the bus capacitor 15 is stabilized, that is, reaches the preset voltage threshold, the external DC power supply 40 starts to charge the power battery 20. By adopting the above in-vehicle charging system 10, the circuit damage caused by the sudden access of a large current to the in-vehicle charging system 10 can be prevented, and the safety and reliability of the in-vehicle charging system 10 are ensured.

[0089] Optionally, the first power conversion module 11 can be a PFC (Power Factor Correction) circuit with a boost function. Exemplarily, the first power conversion module 11 can be a PFC circuit based on a boost circuit. The embodiments of the present application do not specifically limit the implementation form of the first power conversion module 11.

[0090] Optionally, the second power conversion module 12 can be a DC-DC conversion circuit (i.e., DC-to-DC converter) with buck and boost functions. The embodiments of the present application do not specifically limit the implementation form of the second power conversion module 12.

[0091] Exemplarily, when the first power conversion module 11 is a PFC circuit, the second power conversion module 12 is a DC-DC circuit, and the switch module 13 includes a first controllable switch 131, a second controllable switch 132, a third controllable switch 133, and a fourth controllable switch 134, please refer to Figure 8 , Figure 8 which is a schematic structural diagram of another in-vehicle charging system provided by the embodiments of the present application. As Figure 8 shown, the first power conversion module 11 can include three inductors (here it is assumed to include a first inductor L1, a second inductor L2, and a third inductor L3) and eight switching tubes (here it is assumed to include a first switching tube T11, a second switching tube T12, a third switching tube T13, a fourth switching tube T14, a fifth switching tube T15, a sixth switching tube T16, a seventh switching tube T17, and an eighth switching tube T18).

[0092] The first end of the first inductor L1 can be connected to the AC power interface 30, and the second end of the first inductor L1 can be connected to the first end of the first switching transistor T11 and the first end of the second switching transistor T12. The first end of the second inductor L2 can be connected to the AC power interface 30, and the second end of the second inductor L2 can be connected to the first end of the third switching transistor T13 and the first end of the fourth switching transistor T14. The first end of the third inductor L3 can be connected to the selection switch 16, and the second end of the third inductor L3 can be connected to the first end of the fifth switching transistor T15 and the first end of the sixth switching transistor T16.

[0093] The second end of the first switching transistor T11 can also be connected to the second end of the third switching transistor T13, and the first end of the first switching transistor T11 can also be connected to the first end of the second switching transistor T12. The second end of the second switching transistor T12 can also be connected to the second end of the fourth switching transistor T14. The first end of the third switching transistor T13 can also be connected to the first end of the fourth switching transistor T14, and the second end of the third switching transistor T13 can also be connected to the second end of the fifth switching transistor T15. The second end of the fourth switching transistor T14 can also be connected to the second end of the sixth switching transistor T16. The first end of the fifth switching transistor T15 can also be connected to the first end of the sixth switching transistor T16, and the second end of the fifth switching transistor T15 can also be connected to the second end of the seventh switching transistor T17. The second end of the sixth switching transistor T16 can also be connected to the second end of the eighth switching transistor T18. The first end of the seventh switching transistor T17 can also be connected to the first end of the eighth switching transistor T18 and the AC power interface 30, and the second end of the seventh switching transistor T17 can also be connected to the bus capacitor 15, the first controllable switch 131, and the third controllable switch 133. The first end of the eighth switching transistor T18 can also be connected to the AC power interface 30 and the negative pole of the external DC power supply 40, and the second end of the eighth switching transistor T18 can also be connected to the bus capacitor 15, the second controllable switch 132, and the fourth controllable switch 134.

[0094] The second power conversion module 12 can include eight switching transistors (here it is assumed to include the ninth switching transistor T21, the tenth switching transistor T22, the eleventh switching transistor T23, the twelfth switching transistor T24, the thirteenth switching transistor T25, the fourteenth switching transistor T26, the fifteenth switching transistor T27, and the sixteenth switching transistor T28), a transformer T, two inductors (here it is assumed to include the fourth inductor L4 and the fifth inductor L5), and two capacitors (here it is assumed to include the first capacitor C1 and the second capacitor C2).

[0095] The first end of the ninth switching transistor T21 can be connected to the first end of the tenth switching transistor T22 and the transformer T, and the second end of the ninth switching transistor T21 can be connected to the third controllable switching device 133 and the eleventh switching transistor T23. The first end of the tenth switching transistor T22 can also be connected to the transformer T, and the second end of the tenth switching transistor T22 can also be connected to the second end of the twelfth switching transistor T24 and the fourth controllable switch 134. The first end of the eleventh switching transistor T23 can be connected to the first end of the twelfth switching transistor T24 and the transformer T. The first end of the twelfth switching transistor T24 can also be connected to the transformer T. The first end of the thirteenth switching transistor T25 can be connected to the first end of the fourteenth switching transistor T26 and the transformer T, and the second end of the thirteenth switching transistor T25 can be connected to the fifteenth switching transistor T27. The first end of the fourteenth switching transistor T26 can also be connected to the transformer T, and the second end of the fourteenth switching transistor T26 can be connected to the second end of the sixteenth switching transistor T28 and the ground terminal. The first end of the fifteenth switching transistor T27 can be connected to the first end of the sixteenth switching transistor T28 and the transformer T. The first end of the sixteenth switching transistor T28 can also be connected to the transformer T, and the second end of the sixteenth switching transistor T28 can also be connected to the ground terminal.

[0096] It should be noted that the above-mentioned ninth switching transistor T21 and tenth switching transistor T22 can be the switching transistors included in the first phase bridge arm 121 of the second power conversion module 12 described above. The eleventh switching transistor T23 and twelfth switching transistor T24 can be the switching transistors included in the second phase bridge arm 122 of the second power conversion module 12 described above. The thirteenth switching transistor T25 and fourteenth switching transistor T26 can be the switching transistors included in the third phase bridge arm of the second power conversion module 12 described above. The fifteenth switching transistor T27 and sixteenth switching transistor T28 can be the switches included in the fourth phase bridge arm of the second power conversion module 12 described above. The embodiments of the present application do not make specific limitations in this regard.

[0097] In the embodiments of the present application, the switching transistor can specifically be an insulated gate device, such as an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) or a metal-oxide-semiconductor field-effect transistor (Metal-Oxide-Semiconductor Field-Rffect Transistor, MOSFET), etc. The embodiments of the present application do not make specific limitations on the implementation form of the switching transistor.

[0098] Optionally, when the first power conversion module 11 is connected to the power battery 20 through the switch module 13 and the second power conversion module 12, and the external DC power supply 40 is a photovoltaic module, the first power conversion module 11 can boost the current input to the first power conversion module 11 through the MPPT (Maximum Power Point Tracking) algorithm.

[0099] In the above implementation, the first power conversion module 11 of the on-vehicle charging system 10 can use the MPPT algorithm to detect the power generation voltage of the photovoltaic module in real time and track the maximum voltage and current value, so as to boost the current input to the first power conversion module 11, enabling the on-vehicle charging system 10 to charge the power battery 20 with the maximum power output current.

[0100] It should be noted that the on-vehicle charging system 10 provided in this application can be used as an on-board charger (OBC) for an electric vehicle to charge the power battery 20 of the electric vehicle. The first power conversion module 11 described above can be a PFC circuit in an existing OBC of an electric vehicle, and the second power conversion module 12 described above can be a high-voltage DC-DC circuit in an existing OBC of an electric vehicle.

[0101] Optionally, the control module 14 can be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The implementation form of the control module 14 in the embodiments of this application is not specifically limited.

[0102] Next, a control method for an on-vehicle charging system will be introduced. This method can be applied to the control module 14 in the on-vehicle charging system 10 described above. In this embodiment, the specific structure and functions of the on-vehicle charging system 10 can be referred to the corresponding descriptions in the foregoing embodiments, and will not be elaborated herein.

[0103] Please refer to Figure 9 , Figure 9 , which is a schematic flowchart of a control method for an on-vehicle charging system provided by an embodiment of this application.

[0104] As Figure 9 shown, the control method specifically may include the following steps:

[0105] S901. Obtain the first port voltage of the first power conversion module and the voltage of the power battery.

[0106] In some feasible embodiments, when the on-vehicle charging system 10 charges the power battery through an external DC power supply, the control module 14 can obtain the first port voltage of the first power conversion module 11 and the voltage of the power battery 20.

[0107] Among them, the first port voltage of the first power conversion module 11 is the voltage of the port between the first power conversion module 11 and the switch module 13. The voltage of the power battery 20 is also the second port voltage of the second power conversion module 12, which can also be said to be the output voltage of the second power conversion module 12.

[0108] Here, the specific process by which the control module 14 can obtain the first port voltage of the first power conversion module 11 and the second port voltage of the second power conversion module 12 can refer to the process of obtaining the first port voltage of the first power conversion module 11 and the second port voltage of the second power conversion module 12 described above, and will not be elaborated here.

[0109] S902. Control the switch module according to the first port voltage and the voltage of the power battery, so that the first power conversion module is directly connected to the power battery, or the first power conversion module is connected to the power battery through the second power conversion module.

[0110] In some feasible embodiments, the control module 14 can control the switch module 13 according to the first port voltage of the first power conversion module 11 and the voltage of the power battery 20, so that the first power conversion module 11 is directly connected to the power battery 20, or the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0111] Among them, the first power conversion module 11 can be used to convert the received first current into first direct current and output it. And when the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12, the second power conversion module 12 is used to convert the first direct current from the first power conversion module 11 into second direct current and charge the power battery 20 with the second direct current.

[0112] Here, the specific process by which the control module 14 controls the switch module 13 according to the first port voltage of the first power conversion module 11 and the voltage of the power battery 20 can refer to the process of the control module 14 controlling the switch module 13 according to the first port voltage of the first power conversion module 11 and the voltage of the power battery 20 described above, and will not be elaborated here.

[0113] Optionally, the control module 14 may first determine the target voltage difference according to the first port voltage and the power battery 20 voltage. Further, if the control module 14 determines that the target voltage difference is within the preset voltage range, it may control the switch module 13 to directly connect the first power conversion module 11 to the power battery 20. If the control module 14 determines that the target voltage difference is not within the preset voltage range, it may control the switch module 13 to connect the first power conversion module 11 to the power battery 20 through the second power conversion module 12.

[0114] Optionally, the switch module 13 in the vehicle-mounted charging system 10 may include the first controllable switch 131 and the second controllable switch 132 described above. For the specific structure and function of the switch module 13, reference may be made to the corresponding description in the foregoing embodiments, and details are not described herein again. The control module 14 may control the first controllable switch 131 and the second controllable switch 132 to conduct, and control the second power conversion module 12 to disconnect, so that the first power conversion module 11 is directly connected to the power battery 20.

[0115] The control module 14 may also control the first controllable switch 131 and the second controllable switch 132 to turn off, and control the second power conversion module 12 to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0116] Optionally, the switch module 13 in the vehicle-mounted charging system 10 may further include the third controllable switch 133 and the fourth controllable switch 134 described above. For the specific structure and function of the switch module 13, reference may be made to the corresponding description in the foregoing embodiments, and details are not described herein again. The control module 14 may control the first controllable switch 131 and the second controllable switch 132 to conduct, and control the third controllable switch 133 and the fourth controllable switch 134 to turn off, so that the first power conversion module 11 is directly connected to the power battery 20.

[0117] Optionally, the control module 14 may also control the first controllable switch 131 and the second controllable switch 132 to turn off, and control the third controllable switch 133 and the fourth controllable switch 134 to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0118] Optionally, the second power conversion module 12 in the in-vehicle charging system 10 may at least include the first phase bridge arm 121 and the second phase bridge arm 122 described above. For the specific structures and functions of the switching module 13 and the second power conversion module 12, reference may be made to the corresponding descriptions in the foregoing embodiments, and details will not be elaborated herein. The control module 14 may control the first controllable switch 131 and the second controllable switch 132 to conduct, and control the switching tubes included in the first phase bridge arm 121 and the second phase bridge arm 122 to turn off, so that the first power conversion module 11 is directly connected to the power battery 20.

[0119] Optionally, the control module 14 may also control the first controllable switch 131 and the second controllable switch 132 to turn off, and control the switching tubes included in the first phase bridge arm 121 and the second phase bridge arm 122 to conduct, so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0120] In the above implementation, the control module 14 may control the switching module 13 according to the voltage of the first port of the first power conversion module 11 and the voltage of the power battery 20, so that the first power conversion module 11 is directly connected to the power battery 20, or the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12, thereby controlling whether the second power conversion module 12 is used in the in-vehicle charging system 10, reducing the power loss during the charging process of the in-vehicle charging system 10, and improving the charging efficiency of the in-vehicle charging system 10.

[0121] In an alternative embodiment, please refer to Figure 10 , Figure 10 which is a schematic flowchart of another control method for an in-vehicle charging system provided by an embodiment of the present application. It should be understood that step S903 should be before S901. As Figure 10 shown, the method may further include the following steps:

[0122] S903, if it is determined that the voltage of the first port is less than a preset voltage threshold, control the switching module so that the first power conversion module is connected to the power battery through the second power conversion module, and control the power battery to charge the bus capacitor of the first power conversion module.

[0123] In some feasible embodiments, before the control module 14 obtains the voltage of the first port of the first power conversion module 11 and the voltage of the power battery 20, if it is determined that the voltage of the first port is less than a preset voltage threshold, the control module 14 may control the switching module 13 so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12, and may control the power battery 20 to charge the bus capacitor 15 of the first power conversion module 11.

[0124] Here, when the control module 14 determines that the voltage of the first port is less than the preset voltage threshold, it controls the switch module 13 so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12. The specific process of controlling the power battery 20 to charge the bus capacitor 15 of the first power conversion module 11 can be referred to the corresponding description in the foregoing embodiments, and will not be elaborated here.

[0125] S904. If it is determined that the voltage of the first port is greater than or equal to the preset voltage threshold, the switch module is controlled so that the first power conversion module is directly connected to the power battery.

[0126] In some feasible embodiments, before the control module 14 obtains the voltage of the first port of the first power conversion module 11 and the voltage of the second port of the power battery 20, if it is determined that the voltage of the first port is greater than or equal to the preset voltage threshold, the switch module 13 can be controlled so that the first power conversion module 11 is directly connected to the power battery 20.

[0127] Here, when the control module 14 determines that the voltage of the first port is greater than or equal to the preset voltage threshold, the specific process of controlling the switch module 13 so that the first power conversion module 11 is directly connected to the power battery 20 can be referred to the corresponding description in the foregoing embodiments, and will not be elaborated here.

[0128] In an alternative embodiment, the on-vehicle charging system 10 may further include the gating switch 16 described above. The specific structure and function of the gating switch 16 can be referred to the corresponding description in the foregoing embodiments, and will not be elaborated here. Please refer to Figure 11 , Figure 11 is a schematic flowchart of another control method for the on-vehicle charging system provided by the embodiments of the present application. It should be understood that step S905 should be before S903. As Figure 11 shown, the method may further include the following steps:

[0129] S905. If it is determined that the first end and the third end of the gating switch are connected, the switch module is controlled so that the first power conversion module is connected to the power battery through the second power conversion module.

[0130] In some feasible embodiments, if the control module 14 determines that the first end and the third end of the gating switch 16 are connected, the switch module 13 can be controlled so that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12.

[0131] Here, when the control module 14 determines that the first end and the third end of the gating switch 16 are connected, the control of the switch module 13 such that the first power conversion module 11 is connected to the power battery 20 through the second power conversion module 12 can be referred to the corresponding description in the foregoing embodiments, and will not be elaborated here.

[0132] S906. If it is determined that the second end and the third end of the gating switch are connected, then perform the step of obtaining the voltage of the first port of the first power conversion module and the voltage of the power battery.

[0133] In some feasible embodiments, if the control module 14 determines that the second end and the third end of the gating switch 16 are connected, then the step of obtaining the voltage of the first port of the first power conversion module 11 and the voltage of the power battery 20 described above can be executed.

[0134] The embodiments of the present application further provide an electric vehicle. Please refer to Figure 12 , Figure 12 is a schematic structural diagram of an electric vehicle provided by the embodiments of the present application. As Figure 12 shown, the electric vehicle may include the on-vehicle charging system 10 described in the foregoing embodiments. Further, the electric vehicle may further include the AC power interface 30, the external DC power supply 40, and the power battery 20 described above. In actual operation, the electric vehicle can supply power to the power battery 20 through the on-vehicle charging system 10.

[0135] It should be understood that Figure 12 is only illustrative. In actual implementation, the electric vehicle may further include other functional components, such as an electric motor, an on-vehicle computer, etc. For the sake of brevity, Figure 12 they are not shown one by one here.

[0136] It should also be noted that the electric vehicles involved in the present application may include pure electric vehicles (PEV / BEV), hybrid electric vehicles (HEV), range extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), new energy vehicles, etc.

[0137] It should be noted that, for any of the above embodiments of the in-vehicle charging system, its control method, and the vehicle, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should be aware that this application is not limited by the described action sequence, because according to this application, some of its steps can be carried out in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily essential to this application.

[0138] The terms "first", "second", etc. in the specification, claims, and the above-mentioned drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps is not limited to the listed steps, but optionally further includes steps not listed, or optionally further includes other steps inherent to these processes, methods, products, or devices.

[0139] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The appearance of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art understand explicitly and implicitly that the embodiments described herein can be combined with other embodiments.

[0140] Although this application has been described in connection with various embodiments herein, however, in the process of implementing the claimed application, those skilled in the art can understand and achieve other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude a plurality. Certain measures are recited in mutually different dependent claims, but this does not indicate that these measures cannot be combined to produce good results.

[0141] The above has introduced the embodiments of this application in detail. Specific examples are used herein to elaborate on the principle and implementation manner of an in-vehicle charging system, its control method, and an electric vehicle of this application. The description of the above embodiments is intended to help understand the method and core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of an in-vehicle charging system, its control method, and an electric vehicle of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

[0142] Those skilled in the art should be able to realize that in one or more of the above examples, the functions described in this application can be implemented by hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, where communication media includes any medium that facilitates the transfer of a computer program from one place to another. The storage media can be any available medium accessible by a general-purpose or special-purpose computer.

[0143] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of this application. It should be understood that the above description is only the specific embodiments of this application and is not used to limit the protection scope of this application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of this application should be included in the protection scope of this application.

Claims

1. A vehicle-mounted charging system, characterized in that, the vehicle-mounted charging system includes a first power conversion module, a second power conversion module, a switching module and a control module. The control module is respectively connected to the first power conversion module, the second power conversion module and the switching module. The switching module is also respectively connected to the first power conversion module and the power battery. The second power conversion module is also connected to the power battery; the control module is used to control the switching module so that the first power conversion module is directly connected to the power battery, or the first power conversion module is connected to the power battery through the second power conversion module.

2. The vehicle-mounted charging system according to claim 1, characterized in that, the first power conversion module is used to convert the received first current into first direct current and output it; when the first power conversion module is connected to the power battery through the second power conversion module, the second power conversion module is used to convert the first direct current from the first power conversion module into second direct current and charge the power battery with the second direct current.

3. The vehicle-mounted charging system according to claim 2, characterized in that, the control module is further used for: acquiring the first port voltage of the first power conversion module and the voltage of the power battery, and determining a target voltage difference according to the first port voltage and the voltage of the power battery, where the first port voltage is the voltage of the port of the first power conversion module used to be connected to the switching module; if it is determined that the target voltage difference is within a preset voltage range, controlling the switching module so that the first power conversion module is directly connected to the power battery; if it is determined that the target voltage difference is not within the preset voltage range, controlling the switching module so that the first power conversion module is connected to the power battery through the second power conversion module.

4. The vehicle-mounted charging system according to claim 3, characterized in that, the switching module includes a first controllable switch and a second controllable switch. The first port of the first power conversion module is connected to the first end of the power battery through the first controllable switch. The second port of the first power conversion module is connected to the second end of the power battery through the second controllable switch. The control module is respectively connected to the first controllable switch and the second controllable switch.

5. The vehicle-mounted charging system according to claim 4, characterized in that, the control module is used for: if it is determined that the target voltage difference is within the preset voltage range, controlling the first controllable switch and the second controllable switch to conduct, and controlling the second power conversion module to disconnect, so that the first power conversion module is directly connected to the power battery; If it is determined that the target voltage difference is not within the preset voltage range, control the first controllable switch and the second controllable switch to turn off, and control the second power conversion module to turn on, so that the first power conversion module is connected to the power battery through the second power conversion module.

6. The on-vehicle charging system according to claim 4 or 5, wherein, the switch module further includes a third controllable switch and a fourth controllable switch. The first port of the first power conversion module is further connected to the first port of the second power conversion module through the third controllable switch, and the second port of the first power conversion module is further connected to the second port of the second power conversion module through the fourth controllable switch. The control module is respectively connected to the third controllable switch and the fourth controllable switch.

7. The on-vehicle charging system according to claim 6, wherein, the control module is configured to: if it is determined that the target voltage difference is within the preset voltage range, control the first controllable switch and the second controllable switch to turn on, and control the third controllable switch and the fourth controllable switch to turn off, so that the first power conversion module is directly connected to the power battery; if it is determined that the target voltage difference is not within the preset voltage range, control the first controllable switch and the second controllable switch to turn off, and control the third controllable switch and the fourth controllable switch to turn on, so that the first power conversion module is connected to the power battery through the second power conversion module.

8. The on-vehicle charging system according to claim 4 or 5, wherein, the second power conversion module at least includes a first phase bridge arm and a second phase bridge arm. The control module is respectively connected to the first controllable switch and the second controllable switch. The first port of the first power conversion module is further respectively connected to the first end of the first phase bridge arm and the first end of the second phase bridge arm, and the second port of the first power conversion module is further respectively connected to the second end of the first phase bridge arm and the second end of the second phase bridge arm.

9. The on-vehicle charging system according to claim 8, wherein, the control module is further configured to: if it is determined that the target voltage difference is within the preset voltage range, control the first controllable switch and the second controllable switch to turn on, and control the switching tubes included in the first phase bridge arm and the second phase bridge arm to turn off, so that the first power conversion module is directly connected to the power battery; if it is determined that the target voltage difference is not within the preset voltage range, control the first controllable switch and the second controllable switch to turn off, and control the switching tubes included in the first phase bridge arm and the second phase bridge arm to turn on, so that the first power conversion module is connected to the power battery through the second power conversion module.

10. The on-vehicle charging system according to any one of claims 1-9, wherein, The in-vehicle charging system further includes a selection switch. A first end of the selection switch is connected to an AC interface of the in-vehicle charging system. A second end of the selection switch is connected to an external DC power source. A third end of the selection switch is connected to the first power conversion module.

11. The in-vehicle charging system according to claim 10, wherein, when the first end is connected to the third end, the first current includes a first alternating current provided by the AC interface, and the control module is further configured to control the switching module so that the first power conversion module is connected to the power battery through the second power conversion module; when the second end is connected to the third end, the first current includes a third direct current provided by the external DC power source, and the control module is further configured to control the switching module so that the first power conversion module is directly connected to the power battery, or so that the first power conversion module is connected to the power battery through the second power conversion module.

12. The in-vehicle charging system according to claim 2, wherein, when the first power conversion module is directly connected to the power battery, the power battery is charged by the first direct current.

13. The in-vehicle charging system according to claim 12, wherein, the control module is further connected to the power battery; the control module is further configured to: if it is determined that the voltage of the first port is less than a preset voltage threshold, control the switching module so that the first power conversion module is connected to the power battery through the second power conversion module, and control the power battery to charge the bus capacitor of the first power conversion module; if it is determined that the voltage of the first port is greater than or equal to the preset voltage threshold, control the switching module so that the first power conversion module is directly connected to the power battery.

14. The in-vehicle charging system according to claim 10, wherein, the external DC power source includes a photovoltaic module.

15. A control method for an in-vehicle charging system, wherein, it is applicable to a control module in an in-vehicle charging system, and the method includes: acquiring a first port voltage of a first power conversion module and a voltage of a power battery, where the first port voltage is the voltage of a port of the first power conversion module for connecting to a switching module; controlling the switching module according to the first port voltage and the voltage of the power battery so that the first power conversion module is directly connected to the power battery, or so that the first power conversion module is connected to the power battery through a second power conversion module.

16. An electric vehicle, wherein, the electric vehicle includes the in-vehicle charging system according to any one of claims 1 to 14.

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