Battery management switching circuit and electric vehicle
By installing a switching module on the inverter bridge arm of the electric vehicle, and using the inverter motor windings to form a boost circuit, the battery pack can be self-heated, which solves the problem of decreased charging and discharging performance of electric vehicles in low-temperature environments and improves their performance in low-temperature conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- VOLKSWAGEN (CHINA) TECHNOLOGY CO LTD
- Filing Date
- 2025-07-22
- Publication Date
- 2026-07-21
AI Technical Summary
Electric vehicles experience reduced charging and discharging performance in low-temperature environments, leading to insufficient power and shortened driving range, thus affecting normal use.
By installing a switching module on the inverter arm of the electric vehicle, and using the inverter's motor windings to form a boost circuit when the charging switch module is closed, the energy from the external charging equipment is converted into a pulse current that is then injected into the battery pack for self-heating.
It enhances the charging and discharging performance of electric vehicles in low-temperature environments, solves the problems of insufficient power and shortened driving range, and improves the performance in low-temperature environments.
Smart Images
Figure CN224528475U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, and more particularly to a battery management switching circuit and an electric vehicle. Background Technology
[0002] Electric vehicles are powered by a high-voltage battery that supplies energy to an electric motor, which in turn drives the vehicle. When the high-voltage battery's charge is insufficient, it needs to be charged through the electric vehicle's charging port. A high-voltage battery refers to a battery with a voltage exceeding 200V.
[0003] The charging and discharging performance of high-voltage batteries in electric vehicles is affected by temperature. When the temperature is below zero degrees Celsius, their charging and discharging performance will drop sharply. This will lead to problems such as insufficient power and shortened driving range in low-temperature environments, which will seriously restrict their normal use in low-temperature environments. Utility Model Content
[0004] This application provides a battery management switching circuit and an electric vehicle to solve the aforementioned technical problems in the prior art.
[0005] According to a first aspect of this application, a battery management switch circuit is provided, including a charging switch module, a first switching switch module, and a second switching switch module.
[0006] The charging switch module is used to connect the charging equipment to the battery pack in the electric vehicle.
[0007] The first switching module is mounted on one arm of the inverter of the electric vehicle, and the inverter is connected to the battery pack and the charging switch module.
[0008] One end of the second switching module is connected to the end of the first switching module near the inverter, and the other end of the second switching module is connected to the battery pack;
[0009] When the charging switch module is closed, the first switching switch module is open, the second switching switch module is closed, and the output voltage of the charging device is lower than the voltage of the battery pack, the energy of the charging device is used to heat the battery pack.
[0010] In some embodiments, the charging switch module includes at least one of a first switching device and a second switching device;
[0011] The first electrode of the battery pack and one end of the inverter are connected to the first end of the charging device through the first switching device.
[0012] The second electrode of the battery pack and the other end of the inverter are connected to the second end of the charging device via the second switching device.
[0013] In some embodiments, the first switching device and the second switching device respectively include any one of a transistor, an IGBT (insulated gate bipolar transistor), and a MOSFET (metal-oxide-semiconductor field-effect transistor).
[0014] In some embodiments, the first switching module includes at least one semiconductor switching device, and the second switching module includes at least one semiconductor switching device.
[0015] In some embodiments, the battery management switch circuit further includes a series-parallel switching module; the battery pack includes at least two battery packs, and the first electrode and the second electrode of the two battery packs are respectively connected to the charging switch module;
[0016] The series-parallel switching module is connected between the first electrodes of the two battery packs and between the second electrodes of the two battery packs, for connecting the two battery packs in series or in parallel.
[0017] When the charging switch module is closed, the first switching switch module is open, the second switching switch module is closed, the series-parallel switching switch module connects the two battery packs in parallel, and the output voltage of the charging device is lower than the voltage of the battery pack, the energy of the charging device is used to heat the battery pack.
[0018] When the charging switch module is closed, the first switching switch module is closed, the second switching switch module is open, the series-parallel switching switch module connects the two battery packs in parallel or in forward series, and the output voltage of the charging device is greater than or equal to the voltage of the battery pack, the charging device charges the battery pack.
[0019] When the charging switch module is open, the first switching switch module is open, the second switching switch module is closed, and the series-parallel switching switch module connects the two battery packs in reverse series, the energy of the motor connected to the inverter and the energy of one of the battery packs are used to heat the other battery pack.
[0020] When the charging switch module is open, the first switching switch module is open, the second switching switch module is closed, and the series-parallel switching switch module connects the two battery packs in parallel, the energy of the motor connected to the inverter heats the parallel battery packs.
[0021] In some embodiments, the series-parallel switching module includes a fifth switching device, a sixth switching device, a seventh switching device, and an eighth switching device;
[0022] One end of the fifth switching device is connected to the first electrode of the first battery pack, and the other end of the fifth switching device is connected to the first electrode of the second battery pack through the sixth switching device;
[0023] The eighth switching device is connected between the second electrodes of the two battery packs;
[0024] One end of the seventh switching device is connected between the fifth and sixth switching devices, and the other end of the seventh switching device is connected between the second electrode of the first battery pack and the eighth switching device.
[0025] In some embodiments, the battery management switch circuit further includes a controller connected to the charging switch module, the first switching switch module, and the second switching switch module.
[0026] According to a second aspect of this application, an electric vehicle is provided, including a battery pack and the aforementioned battery management switch circuit, the battery management switch circuit being connected to the battery pack.
[0027] In some embodiments, the battery pack includes at least two battery packs, the two battery packs being 400V battery packs.
[0028] In summary, the battery management switching circuit and electric vehicle provided in this application have at least the following beneficial effects:
[0029] The battery pack of the electric vehicle is connected to the charging equipment through a charging switch module. A first switching switch module is set on one arm of the inverter of the electric vehicle. A second switching switch module is connected to the battery pack between the first switching switch module and the inverter. When the output voltage of the charging equipment connected to the charging switch module is closed and the voltage of the battery pack is lower than that of the battery pack, the first switching switch module is opened and the second switching switch module is closed. This allows the winding of the motor connected to the inverter to be reused to form a boost circuit. The energy of the external charging equipment is converted into pulse current and injected into the battery pack to achieve self-heating. This solves the problems of decreased charging and discharging performance, insufficient power and shortened driving range caused by low temperature operation, and enhances the charging and discharging performance of electric vehicles in low temperature environments. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the specific embodiments of this application, the accompanying drawings used in the specific embodiments will be briefly introduced below in conjunction with the accompanying drawings. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings or solutions can be obtained based on these drawings without creative effort.
[0031] Figure 1This is a circuit topology diagram of the battery management switch circuit in one embodiment of this application;
[0032] Figure 2 This is a circuit topology diagram of the battery management switch circuit in another embodiment of this application;
[0033] Figure 3 This is a schematic diagram illustrating the switching states of each switching device in a battery management switching circuit under multiple operating modes in one embodiment of this application. Detailed Implementation
[0034] In the description of this application, it should be understood that the use of terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" to indicate orientation or positional relationship, unless otherwise specified, is understood to be based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0035] Furthermore, features specified with "first" or "second" for descriptive purposes only should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified with "first" or "second" may explicitly or implicitly include at least one of the specified features. The description of "multiple" generally means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0036] In this application, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0037] In the description of this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0038] In one embodiment of this application, a battery management switching circuit is provided for at least battery heating management of the battery pack of an electric vehicle. (Reference) Figure 1 The battery management switching circuit includes a charging switch module 110, a first switching switch module 120, and a second switching switch module 130. Each of these modules includes at least one switching device, and can switch the switching state of its switching devices by receiving a voltage level signal. For example, a controller can output a first voltage level to deactivate the charging switch module 110, the first switching switch module 120, and the second switching switch module 130, and output a second voltage level to deactivate them.
[0039] The charging switch module 110 is used to connect the charging equipment to the battery pack in the electric vehicle. Specifically, one end of the battery pack is connected to a first end of the charging equipment via the charging switch module 110, and the other end of the battery pack is connected to a second end of the charging equipment via the charging switch module 110. For example... Figure 1 As shown, the battery pack includes two components: a first battery pack and a second battery pack. The first electrode of the first battery pack is connected to the first electrode of the second battery pack, and the second electrode of the first battery pack is connected to the second electrode of the second battery pack, thus achieving parallel connection.
[0040] In this context, "charging equipment" refers to devices that provide direct current (DC) power, such as DC charging stations. For example, the first electrodes of the first and second battery packs are connected to the first terminal of the charging equipment via a charging switch module 110, and the second electrodes of the first and second battery packs are connected to the second terminal of the charging equipment via the same module. If the first electrode can be positive and the second electrode negative, then the first terminal of the charging equipment is positive, and the second terminal is negative. Figure 1 As shown. This is understandable. Figure 1 This is just one example. In other embodiments, the first electrode may also be the negative electrode, in which case the second electrode may be the positive electrode, the first end of the charging device may be the negative electrode, and the second end of the charging device may be the positive electrode.
[0041] The first switching module 120 is disposed on one arm of the inverter 200 of the electric vehicle, and the inverter is connected to the battery pack and the charging switch module 110. For example, the first switching module 120 is disposed on the first arm of the inverter 200, and each arm of the inverter 200 is connected to the battery pack and the charging switch module 110. Specifically, one end of each arm is connected to the first electrode of the battery pack and the first end of the charging switch module 110, and the other end of each arm is connected to the second electrode of the battery pack and the second end of the charging switch module 110. One end of the second switching module 130 is connected to the end of the first switching module 120 near the inverter 200, and the other end of the second switching module 130 is connected to the battery pack.
[0042] The electric motor 300 of the electric vehicle requires power from the battery pack. The DC voltage output from the battery pack is inverted by the inverter 200 to output AC voltage to drive the electric motor 300. Specifically, taking the inverter 200 as a three-phase bridge arm inverter as an example, the first switching module 120 is located in the first bridge arm of the inverter 200, one end of the second switching module 130 is connected between the first switching module 120 and the first bridge arm, one end of the other bridge arms is connected to the first electrode of the battery pack and the first end of the charging switch module 110, and the other ends of the three bridge arms are all connected to the second electrode of the battery pack. The three bridge arms are respectively connected to the three phase lines of the electric motor 300.
[0043] When the charging switch module 110 is closed, the circuit between the battery pack and the charging device is connected. The second switching switch module 130 closes, connecting the battery pack to the inverter 200. When the first switching switch module 120 is open, one arm of the inverter 200 is disconnected from the charging switch module 110, while the other arms remain connected. The closing of the charging switch module 110 allows current from the charging device to flow into the inverter 200. Specifically, when the charging switch module 110 is closed, the first switching switch module 120 is open, the second switching switch module 130 is closed, and the output voltage of the charging device is lower than the voltage of the battery pack, the windings of the multiplexed motor 300 form a boost circuit, converting the energy of the external charging device into a pulse current that flows into the battery pack. This allows the energy of the charging device to be used to heat the battery pack, operating in the first heating mode. For example, if two 400V battery packs are connected in parallel, the voltage of the battery packs will be 400V. In low-temperature environments, the output voltage of the external charging device can be lower than 400V. By closing the charging switch module 110, opening the first switching switch module 120, and closing the second switching switch module 130, the charging device can be used to heat the battery packs.
[0044] The charging and discharging performance of electric vehicle batteries is affected by temperature. When the temperature drops below zero degrees Celsius, their charging and discharging performance drops sharply, leading to problems such as insufficient power and shortened driving range in low-temperature environments, severely restricting their normal use in such conditions. This application connects the electric vehicle's battery pack to the charging equipment via a charging switch module 110. A first switching switch module 120 is installed on one arm of the electric vehicle's inverter 200, and a second switching switch module 130 connects the first switching switch module 120 to the inverter 200 and then to the battery pack. When the charging switch module 110 is closed and the output voltage of the connected charging equipment is lower than the battery pack's voltage, the first switching switch module 120 is opened and the second switching switch module 130 is closed. This allows the windings of the motor 300 connected to the inverter 200 to be reused to form a boost circuit, converting the energy from the external charging equipment into a pulse current that flows into the battery pack for self-heating. This solves the problems of decreased charging and discharging performance, insufficient power, and shortened driving range caused by low-temperature operation, thereby enhancing the charging and discharging performance of electric vehicles in low-temperature environments.
[0045] In some embodiments, the battery management switch circuit further includes a controller connected to the charging switch module 110, the first switching switch module 120, and the second switching switch module 130, for controlling the switching states of the charging switch module 110, the first switching switch module 120, and the second switching switch module 130. Specifically, the controller outputs a level signal to the charging switch module 110, the first switching switch module 120, and the second switching switch module 130 to control their switching states.
[0046] In some embodiments, the controller includes either the battery management unit of the electric vehicle or the vehicle controller, thereby employing a controller within the electric vehicle to achieve switch control.
[0047] In some embodiments, reference Figure 1 The charging switch module 110 includes at least one of a first switching device S1 and a second switching device S2. The first electrode of the battery pack and one end of the inverter 200 are connected to the first end of the charging device via the first switching device S1. The second electrode of the battery pack and the other end of the inverter 200 are connected to the second end of the charging device via the second switching device S2.
[0048] Specifically, the first switching device S1 and the second switching device S2 can be connected to a controller. The controller controls the connection or disconnection of the charging device by closing or opening the first switching device S1 and the second switching device S2. Specifically, when the first switching device S1 is open, the first electrode of the battery pack is disconnected from the first terminal of the charging device, that is, the charging device is not connected. When the second switching device S2 is open, the second electrode of the battery pack is disconnected from the second terminal of the charging device.
[0049] The charging switch module 110 includes at least one of a first switching device S1 and a second switching device S2. Preferably, it may include both the first switching device S1 and the second switching device S2. When both the first switching device S1 and the second switching device S2 are closed, the charging switch module 110 is closed, and the connection between the battery pack, such as the first battery pack and the second battery pack, and the charging device is established. When either the first switching device S1 or the second switching device S2 is open, the charging switch module 110 is open. In this way, the connection to the charging device can be controlled more reliably.
[0050] In some embodiments, the first switching device S1 and the second switching device S2 can be semiconductor switching devices. Specifically, the first switching device S1 and the second switching device S2 respectively include any one of transistor, IGBT, and MOSFET, which facilitates controller control, realizes automatic switching, and is small in size and light in weight.
[0051] In some embodiments, the first switching module 120 includes at least one semiconductor switching device, and the second switching module 130 includes at least one semiconductor switching device. For example, the semiconductor switching device can be any one of a transistor, IGBT, or MOSFET. Figure 1As shown, the first switching module 120 includes a third switching device S3, and the second switching module 130 includes a fourth switching device S4; the third switching device S3 is disposed on one arm of the inverter. One end of the fourth switching device S4 is connected between the third switching device S3 and one arm of the inverter 200, and the other end is connected to the battery pack.
[0052] Specifically, the third switching device S3 and the fourth switching device S4 can be connected to a controller, which controls the third switching device S3 and the fourth switching device S4 to open or close.
[0053] In some embodiments, reference Figure 2 The battery management switch circuit mentioned above also includes a series-parallel switching module 140; the battery pack includes at least two battery packs, and the first electrode and the second electrode of the two battery packs are respectively connected to the charging switch module 110.
[0054] The series-parallel switching module 140 is connected between the first electrodes of the two battery packs and between the second electrodes of the two battery packs, for switching the series or parallel connection structure of the two battery packs. For example, the two battery packs are a first battery pack and a second battery pack, and the series-parallel switching module 140 is connected between the first electrode of the first battery pack and the first electrode of the second battery pack, and between the second electrode of the first battery pack and the second electrode of the second battery pack.
[0055] In some embodiments, reference Figure 2 The series-parallel switching module 140 includes a fifth switching device S5, a sixth switching device S6, a seventh switching device S7, and an eighth switching device S8. One end of the fifth switching device S5 is connected to the first electrode of the first battery pack, and the other end of the fifth switching device S5 is connected to the first electrode of the second battery pack through the sixth switching device S6. That is, the fifth switching device S5 and the sixth switching device S6 are connected in series in the connection line between the first electrode of the first battery pack and the first electrode of the second battery pack.
[0056] The eighth switch S8 is connected between the second electrodes of the two battery packs. One end of the seventh switch S7 is connected between the fifth switch S5 and the sixth switch S6, and the other end of the seventh switch S7 is connected between the second electrode of the first battery pack and the eighth switch S8.
[0057] By switching the switching states of the fifth switching device S5, the sixth switching device S6, the seventh switching device S7, and the eighth switching device S8, the switching between series and parallel connections of the two battery packs can be achieved. Specifically, the fifth switching device S5, the sixth switching device S6, the seventh switching device S7, and the eighth switching device S8 can be connected to a controller, which controls their switching states. It can be understood that the fifth switching device S1, the sixth switching device S6, the seventh switching device S7, and the eighth switching device S8 can also include any of the following: IGBT, MOSFET, or transistor.
[0058] This application uses a series-parallel switching switch module 140 to switch between two battery packs connected in series or in parallel. Combined with the switching states of the charging switch module 110, the first switching switch module 120, and the second switching switch module 130, it enables switching between different operating modes, such as charging or heating the battery packs. The battery management switch circuit can be used for both battery charging and battery heating control, offering diverse functions. Specifically, the various operating modes are described below:
[0059] (1) Charging modes: series charging mode and parallel charging mode
[0060] When the charging switch module 110 is closed, the first switching switch module 120 is closed, the second switching switch module 130 is open, and the series-parallel switching switch module 140 connects the two battery packs (such as the first battery pack and the second battery pack) in parallel or in forward series, and the output voltage of the charging device is greater than or equal to the voltage of the battery pack, the charging device charges the battery pack. At this time, it is working in charging mode.
[0061] The charging modes include series charging mode and parallel charging mode. Forward series connection refers to connecting the second electrode of the first battery pack to the first electrode of the second battery pack. The series-parallel switching module 130 enables the two battery packs to be connected in the forward series configuration, which is the series charging mode. In this mode, a charging device is used to charge the two battery packs connected in series. For example, in the series charging mode, the switching states of each switching device are as follows: Figure 3 As shown in condition 1, the first switch S1 and the second switch S2 are closed, the third switch S3 is closed, the fourth switch S4 is open, the fifth switch S5 and the eighth switch S8 are open, and the sixth switch S6 and the seventh switch S7 are closed. For example, in series charging mode, an 800V DC charging station can be used to charge an 800V battery pack (composed of a first 400V battery pack and a second 400V battery pack connected in series).
[0062] The series-parallel switching module 140 enables the two battery packs to be connected in parallel, corresponding to the parallel charging mode. In this mode, a charging device is used to charge the two battery packs connected in parallel. For example, in the parallel charging mode, the switching states of each switching device are as follows: Figure 3 As shown in condition 2, condition 2 differs from condition 1 in that, in condition 2, the fifth switch device S5, the sixth switch device 6, and the eighth switch device S8 are closed, while the seventh switch device S7 is open, connecting the two battery packs in parallel. For example, in parallel charging mode, a 400V DC charging station can be used to charge both the 400V first battery pack and the 400V second battery pack.
[0063] By switching the series-parallel connection between the first and second battery packs, a high-voltage charging device can charge the first and second battery packs connected in series, while a low-voltage charging device can charge the first and second battery packs connected in parallel. In this way, it can be compatible with charging devices of different voltages. Compared with a boost module composed of multiple components, the structure is simpler, the cost is lower, and there is no need for secondary boosting, resulting in high charging efficiency.
[0064] (2) First heating mode: using the energy of the charging equipment to heat the battery pack.
[0065] When the charging switch module 110 is closed, the first switching switch module 120 is open, and the second switching switch module 130 is closed, and the series-parallel switching switch module 140 connects the two battery packs in parallel, that is... Figure 3 Under condition 4, when the first switch S1 and the second switch S2 are both closed, the charging switch module 110 is closed, the third switch S3 is open, the fourth switch S4 is closed, the fifth switch S5, the sixth switch S6 and the eighth switch S8 are closed and the seventh switch S7 is open, so that the two battery packs are connected in parallel. If the output voltage of the charging device is less than the voltage of the battery pack, the energy of the charging device is used to heat the parallel battery packs. This is the first heating mode.
[0066] (4) Second heating mode: DMSI (dual-module split inverter) heating mode without external charging device
[0067] When the charging switch module 110 is open, the first switching switch module 120 is open, the second switching switch module 130 is closed, and the series-parallel switching switch module 140 connects the two battery packs in reverse series, the energy of the motor 300 connected to the inverter 200 and the energy of one of the battery packs are used to heat the other battery pack. This is the second heating mode.
[0068] Taking the first and second battery packs as an example, reverse series connection means that the second electrode of the first battery pack is connected to the second electrode of the second battery pack. For example, in the second heating mode, the switching states of each switching device are as follows: Figure 3 As shown in condition 3-1: both the first switch device S1 and the second switch device S2 are open, causing the charging switch module 110 to be disconnected; the third switch device S3 is open; the fourth switch device S4 is closed; the fifth switch device S5, the sixth switch device S6 and the seventh switch device S7 are open and the eighth switch device S8 is closed, causing the two battery packs to be connected in reverse series.
[0069] (5) Third heating mode: CMI heating mode without external charging device
[0070] Specifically, when the charging switch module 110 is open, the first switching switch module 120 is open, the second switching switch module 130 is closed, and the series-parallel switching switch module 140 connects the two battery packs in parallel, the energy stored and released by the coil winding of the motor 300 is used to heat the parallel battery packs. That is, the energy of the motor 300 is used to heat the parallel battery packs; this is the third heating mode: CMI heating mode. For example, in the third heating mode, the switching states of each switching device are as follows: Figure 3 As shown in condition 3-2.
[0071] This application also provides an electric vehicle, including a battery pack and the battery management switch circuit in the above embodiments, wherein the battery management switch circuit is connected to the battery pack.
[0072] In some embodiments, the battery pack includes at least two battery packs, both of which are 400V battery packs.
[0073] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.
[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A battery management switching circuit, characterized in that, Includes a charging switch module, a first switching switch module, and a second switching switch module; The charging switch module is used to connect the charging equipment to the battery pack in the electric vehicle. The first switching module is mounted on one arm of the inverter of the electric vehicle, and the inverter is connected to the battery pack and the charging switch module. One end of the second switching module is connected to the end of the first switching module near the inverter, and the other end of the second switching module is connected to the battery pack; When the charging switch module is closed, the first switching switch module is open, the second switching switch module is closed, and the output voltage of the charging device is lower than the voltage of the battery pack, the energy of the charging device is used to heat the battery pack.
2. The battery management switch circuit according to claim 1, characterized in that, The charging switch module includes at least one of a first switching device and a second switching device; The first electrode of the battery pack and one end of the inverter are connected to the first end of the charging device through the first switching device. The second electrode of the battery pack and the other end of the inverter are connected to the second end of the charging device via the second switching device.
3. The battery management switch circuit according to claim 2, characterized in that, The first switching device and the second switching device respectively include any one of transistor, IGBT, and MOSFET.
4. The battery management switch circuit according to claim 1, characterized in that, The first switching module includes at least one semiconductor switching device, and the second switching module includes at least one semiconductor switching device.
5. The battery management switch circuit according to claim 1, characterized in that, It also includes a series-parallel switching module; the battery pack includes at least two battery packs, and the first and second electrodes of the two battery packs are respectively connected to the charging switch module; The series-parallel switching module is connected between the first electrodes of the two battery packs and between the second electrodes of the two battery packs, for connecting the two battery packs in series or in parallel. When the charging switch module is closed, the first switching switch module is open, the second switching switch module is closed, the series-parallel switching switch module connects the two battery packs in parallel, and the output voltage of the charging device is lower than the voltage of the battery packs, the energy of the charging device is used to heat the parallel battery packs. When the charging switch module is closed, the first switching switch module is closed, the second switching switch module is open, the series-parallel switching switch module connects the two battery packs in parallel or in forward series, and the output voltage of the charging device is greater than or equal to the voltage of the battery pack, the charging device charges the battery pack. When the charging switch module is open, the first switching switch module is open, the second switching switch module is closed, and the series-parallel switching switch module connects the two battery packs in reverse series, the energy of the motor connected to the inverter and the energy of one of the battery packs are used to heat the other battery pack. When the charging switch module is open, the first switching switch module is open, the second switching switch module is closed, and the series-parallel switching switch module connects the two battery packs in parallel, the energy of the motor connected to the inverter heats the parallel battery packs.
6. The battery management switch circuit according to claim 5, characterized in that, The series-parallel switching module includes a fifth switching device, a sixth switching device, a seventh switching device, and an eighth switching device; One end of the fifth switching device is connected to the first electrode of the first battery pack, and the other end of the fifth switching device is connected to the first electrode of the second battery pack through the sixth switching device; The eighth switching device is connected between the second electrodes of the two battery packs; One end of the seventh switching device is connected between the fifth and sixth switching devices, and the other end of the seventh switching device is connected between the second electrode of the first battery pack and the eighth switching device.
7. The battery management switch circuit according to claim 1, characterized in that, It also includes a controller, which is connected to the charging switch module, the first switching switch module and the second switching switch module.
8. An electric vehicle, characterized in that, It includes a battery pack and a battery management switch circuit as described in any one of claims 1-7, wherein the battery management switch circuit is connected to the battery pack.
9. The electric vehicle according to claim 8, characterized in that, The battery pack includes at least two battery packs, and the two battery packs are 400V battery packs.