DC boost charging circuit for power battery and control method thereof

Abstract

The present application relates to the technical field of battery charging, and provides a DC boost charging circuit for a power battery and a control method thereof. The DC boost charging circuit includes: a mains rectifier unit, a high-frequency inverter rectifier unit, a support capacitor, a DC charging interface, a first switch unit, a second switch unit, and a power battery; the output end of the mains rectifier unit is connected to the input end of the high-frequency inverter rectifier unit, the support capacitor is connected between the mains rectifier unit and the high-frequency inverter rectifier unit, and the output end of the high-frequency inverter rectifier unit is connected to the power battery; the output end of the DC charging interface is connected to the power battery, and a first switch unit is provided between the output end of the DC charging interface and the power battery; the output end of the DC charging interface is connected to the output end of the mains rectifier unit, and the second switch unit is provided between the output end of the DC charging interface and the output end of the mains rectifier unit. The present application can boost the output voltage of a DC charging device that is lower than the battery voltage.

Description

Technical Field

[0001] The present application relates to the field of battery charging technology, and in particular to a DC boost charging circuit for a power battery and a control method thereof. Background Art

[0002] Currently, electric vehicle power battery charging methods are primarily categorized as AC slow charging and DC fast charging. AC slow charging involves connecting an onboard charger to the mains electricity supply. The AC charging circuit formed by the onboard charger converts the mains electricity into DC power that matches the battery voltage before charging the power battery. DC fast charging involves connecting a DC charging port to a DC charging device. The DC charging device converts the mains electricity from DC power and then supplies it directly to the power battery through the DC charging circuit. DC fast charging, however, is a key charging method due to its high power output. However, during DC fast charging, the DC charging device's output voltage must not be lower than the power battery's voltage; otherwise, the DC charging device will not be able to charge the battery. For example, if the power battery voltage is 800V and the DC charging device's maximum output voltage is 500V, the DC charging device will not be able to quickly charge the power battery. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems existing in the related art. To this end, this application proposes a DC boost charging circuit for a power battery, which can boost the output voltage of a DC charging device that is lower than the battery voltage, allowing the DC charging device to quickly charge the power battery.

[0004] The present application also proposes an electric vehicle.

[0005] The present application also proposes a method for controlling a DC boost charging circuit of a power battery.

[0006] The present application also proposes a DC boost charging circuit control device for a power battery.

[0007] The present application also provides an electronic device.

[0008] The present application also provides a computer-readable storage medium.

[0009] A DC boost charging circuit for a power battery according to an embodiment of the first aspect of the present application includes:

[0010] An on-board charger, a DC charging interface for connecting to a DC charging device, a first switch unit, a second switch unit, and a power battery;

[0011] The on-board charger includes a mains rectifier unit, a high-frequency inverter rectifier unit, and a support capacitor. The input end of the mains rectifier unit is used to access the mains through the AC charging interface. The output end of the mains rectifier unit is connected to the input end of the high-frequency inverter rectifier unit. The support capacitor is connected between the mains rectifier unit and the high-frequency inverter rectifier unit. The output end of the high-frequency inverter rectifier unit is connected to the power battery.

[0012] The output end of the DC charging interface is connected to the power battery, and the first switch unit is provided between the output end of the DC charging interface and the power battery;

[0013] The output end of the DC charging interface is connected to the output end of the mains rectifier unit, and the second switch unit is arranged between the output end of the DC charging interface and the output end of the mains rectifier unit.

[0014] By connecting the output end of the mains rectifier unit of the on-board charger to the output end of the DC charging interface, and providing a first switch unit between the output end of the DC charging interface and the power battery, and providing a second switch unit between the output end of the DC charging interface and the output end of the mains rectifier unit, when the output voltage of the DC charging device is lower than the battery voltage of the power battery, it is only necessary to disconnect the first switch unit, and the on-board charger capable of external discharge discharges to charge the support capacitor, so that the voltage of the support capacitor reaches the predetermined input voltage of the DC charging interface. After closing the second switch unit, the output voltage of the DC charging device can be pulled up to the battery voltage by the high-frequency inverter rectifier unit, thereby forming a charging circuit from the DC charging device to the high-frequency inverter rectifier unit of the on-board charger and then to the power battery to charge the power battery. Furthermore, without adding a dedicated booster, only a smaller switch unit is needed to boost the output voltage of the DC charging device that is lower than the battery voltage, so that the DC charging device can quickly charge the power battery, reducing costs.

[0015] According to one embodiment of the present application, the high-frequency inverter rectifier unit includes a high-frequency inverter unit and a high-frequency rectifier unit;

[0016] The input end of the high-frequency inverter unit is connected to the output end of the mains rectifier unit, and the output end of the high-frequency inverter unit is connected to the input end of the high-frequency rectifier unit;

[0017] The output end of the high-frequency rectifier unit is connected to the power battery.

[0018] According to one embodiment of the present application, the second switch unit includes a first switch and a second switch;

[0019] One end of the first switch is connected to the positive electrode of the DC charging interface, and the other end of the first switch is connected to the output end of the mains rectifier unit;

[0020] One end of the second switch is connected to the negative electrode of the DC charging interface, and the other end of the second switch is connected to the output end of the AC rectifier unit.

[0021] According to one embodiment of the present application, at least one of the first switch and the second switch is a relay.

[0022] According to one embodiment of the present application, it further includes:

[0023] A pre-charging unit for charging the support capacitor;

[0024] The output end of the pre-charging unit is connected between the second switch unit and the mains rectifier unit.

[0025] According to one embodiment of the present application, the pre-charging unit includes a DC / DC converter.

[0026] According to one embodiment of the present application, it further includes:

[0027] Controller;

[0028] The controller is configured to determine that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, control the first switch unit to be disconnected, and charge the support capacitor;

[0029] It is determined that the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and the second switch unit is controlled to be closed.

[0030] According to one embodiment of the present application, the controller is further configured to:

[0031] It is determined that the maximum voltage is greater than or equal to the battery voltage, the first switch unit is controlled to be closed, and the second switch unit is controlled to be open.

[0032] An electric vehicle according to an embodiment of the second aspect of the present application includes the DC boost charging circuit for the power battery described in any of the above embodiments.

[0033] A method for controlling a DC boost charging circuit of a power battery according to an embodiment of the third aspect of the present application is applied to a controller in the DC boost charging circuit of the power battery according to the above embodiment, including:

[0034] determining that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, controlling the first switch unit to be disconnected, and charging the support capacitor;

[0035] It is determined that the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and then the second switch unit is controlled to be closed.

[0036] A DC boost charging circuit control device for a power battery according to an embodiment of the fourth aspect of the present application includes:

[0037] a capacitor charging control module, configured to determine that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, control the first switch unit to be disconnected, and charge the support capacitor;

[0038] The battery charging control module is configured to determine whether the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface and control the second switch unit to be closed.

[0039] According to an electronic device of an embodiment of the fifth aspect of the present application, the electronic device includes a processor and a memory storing a computer program. When the processor executes the computer program, the DC boost charging circuit control method of the power battery described in any of the above embodiments is implemented.

[0040] According to the computer-readable storage medium of the sixth embodiment of the present application, a computer program is stored thereon, and when the computer program is executed by a processor, the DC boost charging circuit control method of the power battery described in any of the above embodiments is implemented.

[0041] According to the computer program product of the seventh embodiment of the present application, the computer program product includes: when the computer program is executed by a processor, the DC boost charging circuit control method of the power battery as described in any of the above embodiments is implemented.

[0042] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0043] By connecting the output end of the mains rectifier unit of the on-board charger to the output end of the DC charging interface, and providing a first switch unit between the output end of the DC charging interface and the power battery, and providing a second switch unit between the output end of the DC charging interface and the output end of the mains rectifier unit, when the output voltage of the DC charging device is lower than the battery voltage of the power battery, it is only necessary to disconnect the first switch unit, and the on-board charger capable of external discharge discharges to charge the support capacitor, so that the voltage of the support capacitor reaches the predetermined input voltage of the DC charging interface. After closing the second switch unit, the output voltage of the DC charging device can be pulled up to the battery voltage by the high-frequency inverter rectifier unit, thereby forming a charging circuit from the DC charging device to the high-frequency inverter rectifier unit of the on-board charger and then to the power battery to charge the power battery. Furthermore, without adding a dedicated booster, only a smaller switch unit is needed to boost the output voltage of the DC charging device that is lower than the battery voltage, so that the DC charging device can quickly charge the power battery, reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] Figure 1 It is a DC charging circuit for a power battery in the related art;

[0046] Figure 2 It is the AC slow charging and DC fast charging circuit for vehicles in related technologies;

[0047] Figure 3 This is a schematic structural diagram of a DC boost charging circuit for a power battery provided in an embodiment of the present application;

[0048] Figure 4 This is a structural diagram of a DC boost charging circuit for a power battery provided in another embodiment of the present application;

[0049] Figure 5 This is a flow chart of a method for controlling a DC boost charging circuit of a power battery provided in an embodiment of the present application;

[0050] Figure 6 This is a structural diagram of a DC boost charging circuit control device for a power battery provided in an embodiment of the present application;

[0051] Figure 7 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0053] Below, the DC boost charging circuit and control method of the power battery provided in the embodiments of the present application will be introduced and explained in detail through several specific embodiments.

[0054] The charging methods of the power battery of an electric vehicle are mainly divided into two methods: AC slow charging and DC fast charging. AC slow charging is achieved by connecting the on-board charger to the mains power, and using the AC charging circuit formed by the on-board charger to convert the mains power into DC power that matches the battery voltage to charge the power battery. DC fast charging is achieved by connecting the DC charging device to the DC charging interface, and the DC charging device converts the mains power from DC to DC, and then directly supplies it to the power battery through the DC charging circuit. Generally, DC fast charging is an important charging method due to its high power and short charging time. However, if the voltage that the DC charging device can output is lower than the battery voltage of the electric vehicle, then the DC charging device will not be able to charge the battery. For example, electric vehicles that generally use high-voltage power battery packs generally have a battery voltage of around 800V, while the old DC charging equipment has a nominal maximum output voltage of 500V. At this time, the power battery cannot be quickly charged by the DC charging device. For this reason, in the related art, a dedicated boost converter, such as a DC / DC booster, is used to raise the voltage. As Figure 1 As shown, a dedicated boost converter 100 is connected between the DC charging interface 2 and the power battery 5. When the DC charging interface 2 is connected to the DC charging device 200, the boost converter 100 can boost the output voltage of the DC charging device 200, thereby bringing the output voltage of the DC charging device 200 up to the battery voltage of the power battery. However, adding a dedicated boost converter increases the overall cost of the electric vehicle. In actual applications, few DC charging devices have an output voltage lower than the battery voltage, making the cost-effectiveness of adding a dedicated boost converter low.

[0055] Considering that in actual applications, the AC slow charging and DC fast charging circuits of vehicles are usually as follows Figure 2As shown, it includes an on-board charger 1, a DC charging interface 2 and a power battery 5. The on-board charger 1 can be connected to the mains through the AC charging interface 300 and convert the mains into DC power to charge the power battery 5, while the DC charging interface 2 can be directly connected to the DC charging device to charge the power battery 5. Therefore, in one embodiment, Figure 3 As shown, a DC boost charging circuit for a power battery is provided, comprising:

[0056] On-board charger 1, DC charging interface 2 for connecting to DC charging equipment, first switch unit 3, second switch unit 4 and power battery 5;

[0057] The on-board charger 1 includes a mains rectifier unit 11, a high-frequency inverter rectifier unit and a support capacitor C OBC The input end of the mains rectifier unit 11 is used to access the mains through the AC charging interface 300, the output end of the mains rectifier unit 11 is connected to the input end of the high-frequency inverter rectifier unit, and the support capacitor C OBC Connected between the mains rectifier unit 11 and the high-frequency inverter rectifier unit, the output end of the high-frequency inverter rectifier unit is connected to the power battery 5;

[0058] The output end of the DC charging interface 2 is connected to the power battery 5, and the first switch unit 3 is provided between the output end of the DC charging interface 2 and the power battery 5;

[0059] The output end of the DC charging interface 2 is connected to the output end of the mains rectifier unit 11 , and the second switch unit 4 is arranged between the output end of the DC charging interface 2 and the output end of the mains rectifier unit 11 .

[0060] In one embodiment, the mains rectifier unit 11 is used to rectify the mains voltage received from the AC charging interface into DC power and perform power factor compensation. Its output is a DC power of about 500V. The high-frequency inverter rectifier unit is used to achieve isolated DC to DC conversion, and is used to convert the voltage output by the mains rectifier unit 11 into a voltage that matches the power battery 5, and to achieve electrical isolation between the mains and the power battery 5. A support capacitor C is provided between the mains rectifier unit 11 and the high-frequency inverter rectifier unit. OBC .

[0061] In order to better achieve electrical isolation between the mains and the power battery, in one embodiment, as Figure 3 As shown, the high-frequency inverter rectifier unit further includes a high-frequency inverter unit 21 and a high-frequency rectifier unit 22;

[0062] The input end of the high-frequency inverter unit 21 is connected to the output end of the mains rectifier unit 11 , and the output end of the high-frequency inverter unit 21 is connected to the input end of the high-frequency rectifier unit 22 ;

[0063] The output end of the high-frequency rectifier unit 22 is connected to the power battery 5 .

[0064] In one embodiment, the mains rectifier unit 11 includes an AC / DC converter, the high-frequency inverter unit 21 includes a DC / AC converter, and the high-frequency rectifier unit includes an AC / DC converter. Since the on-board charger 1 can usually discharge externally, that is, the mains rectifier unit 11, the high-frequency inverter unit 21 and the high-frequency rectifier unit 22 are all bidirectional, the supporting capacitor C can be connected by converting the mains rectifier unit 11, the high-frequency inverter unit 21 and the high-frequency rectifier unit 22. OBC Charge.

[0065] In one embodiment, if Figure 3 As shown, the first switch unit 3 includes a switch K FastCharge , the switch K FastCharge It can be a relay. Switch K FastCharge One end is connected to the positive pole of DC charging interface 2, and switch K FastCharge The other end is connected to the positive electrode of the power battery 5; the negative electrode of the DC charging interface 2 is connected to the negative electrode of the power battery 5.

[0066] In one embodiment, if Figure 3 As shown, the second switch unit may include a first switch K1 and a second switch K2. One end of the first switch K1 is connected to the positive electrode of the DC charging interface 2, and the other end of the first switch K1 is connected to the output end of the mains rectifier unit 11. One end of the second switch K2 is connected to the negative electrode of the DC charging interface 2, and the other end of the second switch K2 is connected to the output end of the mains rectifier unit 11. The first switch K1 and the second switch K2 may be relays.

[0067] When the DC charging device is connected to the DC charging interface 2, if the output voltage of the DC charging device is lower than the battery voltage of the power battery 5, the first switch unit 3 can be disconnected first. Since the on-board charger 1 is usually a vehicle-mounted charger that can discharge externally, the power battery can be used to support the capacitor C through the on-board charger 1. OBC Charge the support capacitor C OBC The voltage of the support capacitor reaches the predetermined input voltage of the DC charging interface, so that the voltage difference between the two ends of the second switch group will not be too large when the second switch group is closed, thereby avoiding the large current impact and burning of the second switch due to the excessive voltage difference between the two ends when the second switch group is closed. OBCAfter the voltage reaches the predetermined input voltage of the DC charging interface, the second switch unit 4 can be closed, so that the output voltage of the DC charging device can be pulled up to the battery voltage, thereby forming a charging circuit from the DC charging device to the high-frequency inverter rectifier unit of the on-board charger 1 and then to the power battery 5 to charge the power battery 5, so that when the output voltage of the DC charging device is lower than the battery voltage, the DC charging device can quickly charge the power battery.

[0068] By connecting the output end of the mains rectifier unit of the on-board charger to the output end of the DC charging interface, and providing a first switch unit between the output end of the DC charging interface and the power battery, and providing a second switch unit between the output end of the DC charging interface and the output end of the mains rectifier unit, when the output voltage of the DC charging device is lower than the battery voltage of the power battery, it is only necessary to disconnect the first switch unit, and the on-board charger capable of external discharge discharges to charge the support capacitor, so that the voltage of the support capacitor reaches the predetermined input voltage of the DC charging interface. After closing the second switch unit, the output voltage of the DC charging device can be pulled up to the battery voltage by the high-frequency inverter rectifier unit, thereby forming a charging circuit from the DC charging device to the high-frequency inverter rectifier unit of the on-board charger and then to the power battery to charge the power battery. Furthermore, without adding a dedicated booster, only a smaller switch unit is needed to boost the output voltage of the DC charging device that is lower than the battery voltage, so that the DC charging device can quickly charge the power battery, reducing costs.

[0069] Considering that some on-board chargers may not be able to discharge externally, in one embodiment, Figure 4 As shown, it also includes:

[0070] For supporting capacitor C OBC A pre-charging unit 6 for charging;

[0071] The output end of the pre-charging unit 6 is connected between the second switch unit 4 and the mains rectifier unit 11 .

[0072] Specifically, the first end of the pre-charge unit 6 is connected to one end of the first switch K1 connected to the output end of the mains rectifier unit 11, and the second end of the pre-charge unit 6 is connected to one end of the second switch K2 connected to the output end of the mains rectifier unit 11. In this way, the pre-charge unit 6 can be used as a support capacitor C OBC Charge the support capacitor C OBC The voltage reaches the battery voltage Uo of the power battery. The pre-charging unit 6 requires very little power, such as only about 5W, and can be powered by a lead-acid battery. Therefore, the cost of the pre-charging unit 6 is low. Specifically, the pre-charging unit 6 can be an isolated DC / DC converter.

[0073] By connecting the pre-charging unit to pre-charge the supporting capacitor, the voltage of the supporting capacitor reaches the predetermined input voltage of the DC charging interface. In this way, when the second switch group is closed, the voltage difference across the two ends will not be too large, thereby avoiding the second switch being burned due to a large current shock due to the excessive voltage difference across the two ends when the second switch group is closed.

[0074] In one embodiment, the DC boost charging circuit of the power battery may further include a controller (not shown), which is used to obtain the maximum voltage output by the DC charging device through the DC charging interface 2 and then detect the maximum voltage. When it is detected that the maximum voltage output by the DC charging device through the DC charging interface 2 is less than the battery voltage of the power battery 5, the first switch 3 unit is controlled to be disconnected, and the support capacitor C is connected through the vehicle motor or the pre-charging unit. OBC To charge, and at the same time to support the capacitor C OBC The voltage is detected and the support capacitance C is determined OBC When the voltage reaches the predetermined input voltage of the DC charging interface 2, the second switch unit 4 is controlled to be closed.

[0075] Specifically, the controller is used to control the switch K of the first switch unit 3 when it is determined that the maximum voltage output by the DC charging device through the DC charging interface 2 is less than the battery voltage of the power battery 5. FastCharge Disconnect, and then if the onboard charger is a charger that can discharge externally, control the power battery 5 to support the capacitor C OBC Charge the support capacitor C OBC The voltage reaches the predetermined input voltage of the DC charging interface 2. If the onboard charger is not a charger that can discharge externally, the pre-charging unit 6 is controlled to charge the supporting capacitor C OBC Charge the support capacitor C OBC The voltage reaches the predetermined input voltage of the DC charging interface 2. OBC After the voltage reaches the predetermined input voltage of the DC charging interface 2, the controller controls the first switch K1 and the second switch K2 to close, so that the DC charging device, such as the DC charging pile, charges the power battery according to the DC charging process protocol.

[0076] By setting up a controller, and using the controller to control the first switch unit to be disconnected and charge the support capacitor when it is determined that the maximum voltage output by the DC charging device is lower than the battery voltage of the power battery, and to control the second switch unit to be closed when it is determined that the voltage of the support capacitor reaches the predetermined input voltage of the DC charging interface, the output voltage of the DC charging device can be autonomously boosted when the output voltage of the DC charging device is lower than the battery voltage, so that the DC charging device can quickly charge the power battery.

[0077] In one embodiment, the controller is further configured to:

[0078] It is determined that the maximum voltage is greater than or equal to the battery voltage, the first switch unit is controlled to be closed, and the second switch unit is controlled to be open.

[0079] When it is determined that the maximum voltage output by the DC charging device is greater than or equal to the battery voltage, the first switch unit can be disconnected and closed to quickly charge the power battery in a conventional DC fast charging manner.

[0080] In one embodiment, an electric vehicle is further provided, comprising the DC boost charging circuit for the power battery as described in any of the above embodiments.

[0081] The following describes a method for controlling a DC boost charging circuit of a power battery provided in the present application. The method for controlling a DC boost charging circuit of a power battery described below is applied to the controller in the DC boost charging circuit of the power battery described above.

[0082] In one embodiment, if Figure 5 As shown, a method for controlling a DC boost charging circuit of a power battery is provided, comprising:

[0083] Step 101: determining that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, controlling the first switch unit to be disconnected, and charging the support capacitor;

[0084] Step 102 : Determine whether the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and then control the second switch unit to be closed.

[0085] When it is determined that the maximum voltage output by the DC charging device is lower than the battery voltage of the power battery, the first switch unit is controlled to be disconnected and the support capacitor is charged. When it is determined that the voltage of the support capacitor reaches the predetermined input voltage of the DC charging interface, the second switch unit is controlled to be closed. Therefore, when the output voltage of the DC charging device is lower than the battery voltage, the output voltage of the DC charging device can be autonomously boosted, so that the DC charging device can quickly charge the power battery.

[0086] In one embodiment, the method further comprises:

[0087] It is determined that the maximum voltage is greater than or equal to the battery voltage, the first switch unit is controlled to be closed, and the second switch unit is controlled to be open.

[0088] The DC boost charging circuit control device of the power battery provided in the present application is described below. The DC boost charging circuit control device of the power battery described below and the DC boost charging circuit control method of the power battery described above can be referenced to each other.

[0089] In one embodiment, if Figure 6 As shown, a DC boost charging circuit control device for a power battery is provided, comprising:

[0090] a capacitor charging control module 210, configured to determine that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, control the first switch unit to be disconnected, and charge the support capacitor;

[0091] The battery charging control module 210 is configured to determine whether the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and control the second switch unit to be closed.

[0092] In one embodiment, the battery charging control module 210 is further configured to:

[0093] It is determined that the maximum voltage is greater than or equal to the battery voltage, the first switch unit is controlled to be closed, and the second switch unit is controlled to be open.

[0094] Figure 7 An example of a physical structure diagram of an electronic device is shown below. Figure 7 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 may call a computer program in the memory 830 to execute a method for controlling a DC boost charging circuit of a power battery, for example, including:

[0095] determining that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, controlling the first switch unit to be disconnected, and charging the support capacitor;

[0096] It is determined that the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and the second switch unit is controlled to be closed.

[0097] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0098] On the other hand, an embodiment of the present application further provides a storage medium, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the DC boost charging circuit control method for the power battery provided in the above embodiments, for example, including:

[0099] determining that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, controlling the first switch unit to be disconnected, and charging the support capacitor;

[0100] It is determined that the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and the second switch unit is controlled to be closed.

[0101] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0102] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A DC boost charging circuit for a power battery, characterized in that: include: An on-board charger, a DC charging interface for connecting to a DC charging device, a first switch unit, a second switch unit, and a power battery; The on-board charger includes a mains rectifier unit, a high-frequency inverter rectifier unit, and a support capacitor. The input end of the mains rectifier unit is used to access the mains through the AC charging interface. The output end of the mains rectifier unit is connected to the input end of the high-frequency inverter rectifier unit. The support capacitor is connected between the mains rectifier unit and the high-frequency inverter rectifier unit. The output end of the high-frequency inverter rectifier unit is connected to the power battery. The output end of the DC charging interface is connected to the power battery, and the first switch unit is provided between the output end of the DC charging interface and the power battery; The output end of the DC charging interface is connected to the output end of the mains rectifier unit, and the second switch unit is arranged between the output end of the DC charging interface and the output end of the mains rectifier unit; The circuit further includes a controller; The controller is configured to determine that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, control the first switch unit to be disconnected, and charge the support capacitor; It is determined that the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and the second switch unit is controlled to be closed.

2. The DC boost charging circuit for a power battery according to claim 1, characterized in that: The high-frequency inverting and rectifying unit includes a high-frequency inverter unit and a high-frequency rectifier unit; The input end of the high-frequency inverter unit is connected to the output end of the mains rectifier unit, and the output end of the high-frequency inverter unit is connected to the input end of the high-frequency rectifier unit; The output end of the high-frequency rectifier unit is connected to the power battery.

3. The DC boost charging circuit for a power battery according to claim 1, characterized in that: The second switch unit includes a first switch and a second switch; One end of the first switch is connected to the positive electrode of the DC charging interface, and the other end of the first switch is connected to the output end of the mains rectifier unit; One end of the second switch is connected to the negative electrode of the DC charging interface, and the other end of the second switch is connected to the output end of the AC rectifier unit.

4. The DC boost charging circuit for a power battery according to claim 3, characterized in that: At least one of the first switch and the second switch is a relay.

5. The DC boost charging circuit for a power battery according to claim 1, characterized in that: Also includes: A pre-charging unit for charging the support capacitor; The output end of the pre-charging unit is connected between the second switch unit and the mains rectifier unit.

6. The DC boost charging circuit for a power battery according to claim 5, characterized in that: The pre-charging unit includes a DC / DC converter.

7. The DC boost charging circuit for a power battery according to claim 1, characterized in that: The controller is also used for: It is determined that the maximum voltage is greater than or equal to the battery voltage, the first switch unit is controlled to be closed, and the second switch unit is controlled to be open.

8. An electric vehicle, characterized in that: A DC boost charging circuit comprising a power battery according to any one of claims 1 to 7.

9. A method for controlling a DC boost charging circuit of a power battery, characterized in that: A controller used in a DC boost charging circuit of a power battery according to claim 1; The method comprises: determining that the maximum voltage output by the DC charging device through the DC charging interface is less than the battery voltage of the power battery, controlling the first switch unit to be disconnected, and charging the support capacitor; It is determined that the voltage of the support capacitor reaches a predetermined input voltage of the DC charging interface, and the second switch unit is controlled to be closed.

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