Vehicle charging and discharging circuit and vehicle

Abstract

The invention discloses a vehicle charging and discharging circuit and a vehicle. The vehicle charging and discharging circuit comprises a first circuit; a second circuit; a neutral point of the motor is suitable for being connected with a positive electrode of a battery pack through the first circuit, and the neutral point of the motor is also suitable for being connected with a series connection point between the first battery cell group and the second battery cell group through the second circuit; the first confluence end of the motor controller is suitable for being connected with the positive electrode of the battery pack, the second confluence end of the motor controller is suitable for being connected with the negative electrode of the battery pack, and the output end of the motor controller is connected with the input end of the motor. On the premise that no extra power device is added, the voltage reduction charging function and the self-heating function of the battery pack can be achieved at the same time.

Description

Technical Field

[0001] This application relates to the field of charging and discharging technology, and more specifically to a vehicle charging and discharging circuit and a vehicle. Background Technology

[0002] Batteries are an important component of electric vehicles, but their performance is easily affected by temperature, especially in low-temperature environments where battery performance will degrade significantly.

[0003] To address the issue of battery performance degradation in low-temperature environments, electric vehicles are equipped with lithium battery heating systems.

[0004] Furthermore, battery lifespan, charge / discharge capacity, and charging time all directly affect the charging performance of electric vehicles, thus impacting the user experience. Moreover, the current charging circuitry for electric vehicles has poor compatibility with charging stations of different voltage types, making it difficult to achieve optimal high-power charging results.

[0005] In related technologies, the charging circuit of a vehicle is equipped with the ability to perform step-down charging to charge vehicles with low voltage platforms.

[0006] However, the above technical solutions only have one of the functions of battery heating or buck charging, and the additional components used in battery heating or buck charging also greatly increase the cost of the vehicle. Summary of the Invention

[0007] This application is made to address at least one of the aforementioned problems. According to one aspect of this application, a vehicle charging and discharging circuit is provided, the vehicle charging and discharging circuit comprising: a first circuit; a second circuit; a motor, the neutral point of the motor being adapted to be connected to the positive terminal of a battery pack via the first circuit, and the neutral point of the motor being further adapted to be connected to a series connection point between a first battery cell group and a second battery cell group via the second circuit; and a motor controller, the first bus terminal of the motor controller being adapted to be connected to the positive terminal of the battery pack, the second bus terminal of the motor controller being adapted to be connected to the negative terminal of the battery pack, and the output terminal of the motor controller being connected to the input terminal of the motor; wherein, when the first circuit is turned on, the motor controller is in a first control state and The device is adapted to connect to a charging pile so that the charging pile charges the battery pack sequentially through the motor controller, the motor coil, and the first circuit; or the motor controller is in a second control state so that the motor coil charges the battery pack through the first circuit; when the second circuit is on, the motor controller is in a third control state so that the battery pack discharges through the motor controller to the motor coil; or the motor controller is in a fourth control state so that the motor coil charges the battery pack through the second circuit; wherein the battery pack includes a first cell group and a second cell group connected in series.

[0008] In some embodiments of this application, a first terminal of the first circuit is adapted to be connected to the positive terminal of the battery pack, a second terminal of the first circuit is connected to the neutral point of the motor, and a first switch is provided on the first circuit.

[0009] In some embodiments of this application, the first end of the second circuit is adapted to connect the series connection point between the first battery cell group and the second battery cell group, the second end of the second circuit is connected to the neutral point of the motor, and a second switch is provided on the second circuit.

[0010] In some embodiments of this application, the motor controller includes a plurality of bridge arm assemblies connected in parallel between the first bus terminal and the second bus terminal. Each bridge arm assembly includes a first bridge group and a second bridge group connected in series. A first end of the first bridge group is connected to the first bus terminal, a second end of the first bridge group is connected to the first end of the second bridge group, and a second end of the second bridge group is connected to the second bus terminal. The series connection point of the first bridge group and the second bridge group in each bridge arm assembly is connected to a coil of the motor.

[0011] In some embodiments of this application, when the first circuit is turned on, the motor controller controls at least one of the bridge arm assemblies to turn on the first bridge group and turn off the second bridge group, so that the charging pile charges the battery pack sequentially through the turned-on first bridge group, the motor coil, and the first circuit; or the motor controller controls at least one of the bridge arm assemblies to turn on the second bridge group and turn off the first bridge group, so that the motor coil charges the battery pack through the first circuit.

[0012] In some embodiments of this application, when the second circuit is turned on, the motor controller controls at least one of the bridge arm assemblies to turn on the first bridge group and turn off the second bridge group, so that the first battery cell group discharges the coil of the motor through the turned-on first bridge group; or the motor controller controls at least one of the bridge arm assemblies to turn on the second bridge group and turn off the first bridge group, so that the coil of the motor charges the second battery cell group through the second circuit.

[0013] In some embodiments of this application, when the second circuit is turned on, the motor controller controls at least one of the bridge arm assemblies to turn on the second bridge group and turn off the first bridge group, so that the second battery cell group discharges the motor coil through the second circuit; or the motor controller controls at least one of the bridge arm assemblies to turn on the first bridge group and turn off the second bridge group, so that the motor coil charges the first battery cell group through the turned-on first bridge group.

[0014] In some embodiments of this application, both the first bridge group and the second bridge group include insulated gate bipolar transistors.

[0015] In some embodiments of this application, the first bus terminal is connected to the positive terminal of the battery pack via a bus positive circuit, and a third switch is provided on the bus positive circuit; the second bus terminal is connected to the negative terminal of the battery pack via a bus negative circuit, and a fourth switch is provided on the bus negative circuit.

[0016] In some embodiments of this application, the vehicle charging and discharging circuit further includes a capacitor connected in parallel between the first bus terminal and the second bus terminal.

[0017] In some embodiments of this application, the vehicle charging and discharging circuit further includes a third circuit, the first end of which is connected to the first circuit, the second end of which is connected to the first bus terminal, and the third circuit is provided with a resistor and a fifth switch connected in series.

[0018] According to another aspect of this application, a vehicle is provided, the vehicle including the vehicle charging and discharging circuit described above.

[0019] According to the vehicle charging and discharging circuit and vehicle of the present application embodiment, when the first circuit is turned on, the motor controller is in a first control state and connected to the charging pile so that the charging pile charges the battery pack sequentially through the motor controller, the motor coil and the first circuit, or the motor controller is in a second control state so that the motor coil charges the battery pack through the first circuit to achieve step-down charging of the battery pack; when the second circuit is turned on, the motor controller is in a third control state so that the battery pack discharges through the motor controller to the motor coil, or the motor controller is in a fourth control state so that the motor coil charges the battery pack through the second circuit to achieve self-heating of the battery pack.

[0020] Moreover, the vehicle charging and discharging circuit of this application does not add any additional power devices and will not increase additional costs. Attached Figure Description

[0021] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0022] Figure 1 This diagram illustrates the topology of a vehicle charging and discharging circuit according to an embodiment of this application.

[0023] Figure 2 This diagram illustrates the current flow direction during a step-down charging process according to an embodiment of the present application, where both the motor coil and the battery pack are being charged.

[0024] Figure 3 This diagram illustrates the current flow direction during a step-down charging process according to an embodiment of the present application, where the battery pack is charged via the motor coil.

[0025] Figure 4 This diagram illustrates the flow of current when the battery pack discharges to the motor coil during a self-heating process according to an embodiment of this application.

[0026] Figure 5 This diagram illustrates the flow of current when the motor coil charges the battery pack during a self-heating process according to an embodiment of this application.

[0027] Figure 6 This diagram illustrates the flow of current when the battery pack discharges to the motor coil during a self-heating process according to another embodiment of this application.

[0028] Figure 7This diagram illustrates the flow of current when the motor coil charges the battery pack during a self-heating process according to another embodiment of this application.

[0029] Figure 8 A schematic block diagram of a vehicle according to an embodiment of this application is shown. Detailed Implementation

[0030] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application.

[0031] It should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0032] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0033] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0034] To fully understand this application, a detailed structure will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0035] The following is for reference. Figure 1 This application describes a vehicle charging and discharging circuit according to an embodiment of the present application. The vehicle charging and discharging circuit provided in this embodiment includes: a first circuit 141; a second circuit 142; a motor neutral point adapted to be connected to the positive terminal of a battery pack via the first circuit 141, and the motor neutral point is also adapted to be connected to the series connection point between a first battery cell group 111 and a second battery cell group 112 via the second circuit 142; and a motor controller, a first bus terminal of the motor controller adapted to be connected to the positive terminal of the battery pack, a second bus terminal of the motor controller adapted to be connected to the negative terminal of the battery pack, and an output terminal of the motor controller connected to the input terminal of the motor; wherein, when the first circuit 141 is turned on, the motor controller is in a first control state and adapted to connect to the charging circuit. The charging pile allows the charging pile to charge the battery pack sequentially through the motor controller, the motor coil 131, and the first circuit 141; or the motor controller is in a second control state so that the motor coil 131 charges the battery pack through the first circuit 141; when the second circuit 142 is turned on, the motor controller is in a third control state so that the battery pack discharges through the motor controller to the motor coil 131; or the motor controller is in a fourth control state so that the motor coil 131 charges the battery pack through the second circuit 142; wherein, the battery pack includes a first cell group 111 and a second cell group 121 connected in series.

[0036] Specifically, during charging, the vehicle's charging and discharging circuit can be connected to a charging station. The positive terminal of the charging station is connected to the positive terminal of the battery pack and the first bus terminal of the motor controller, while the negative terminal of the charging station is connected to the negative terminal of the battery pack and the second bus terminal of the motor controller.

[0037] When the first circuit 141 is turned on, the motor controller is in a first control state, connecting the charging pile, motor controller, motor, first circuit 141, and battery pack to form a circuit. The electrical energy from the charging pile is supplied to the motor coil 131 through the motor controller. The motor coil 131 acts as an inductor, and the charging pile charges and stores energy in the motor coil 131. Then, the electrical energy is supplied to the battery pack through the first circuit 141 to charge the battery pack. Afterward, the motor controller is in a second control state, connecting the motor, first circuit 141, battery pack, and motor controller to form a circuit. The motor coil 131 discharges, and the released electrical energy charges the battery pack through the first circuit 141, thereby reducing the charging voltage to the battery pack and achieving step-down charging.

[0038] When the second circuit 142 is turned on, the motor controller is in the third control state, forming a loop between the battery pack, motor controller, motor, and second circuit 142. The battery pack can supply power to the motor coil 131 through the motor controller, with the motor coil 131 acting as an inductor, and the battery pack charges and stores energy in the motor coil 131. Afterwards, the battery pack stops discharging, and the motor controller is in the fourth control state, allowing the motor coil 131 to charge the battery pack through the second circuit 142. The charging current heats the internal resistance of the battery pack, achieving self-heating.

[0039] Based on this, this application provides a vehicle charging and discharging circuit that combines step-down charging and self-heating functions for the battery pack. According to the vehicle charging and discharging circuit of this application, when the first circuit 141 is turned on, the motor controller is in a first control state and connected to the charging pile so that the charging pile charges the battery pack sequentially through the motor controller, the motor coil 131, and the first circuit 141; or the motor controller is in a second control state so that the motor coil 131 charges the battery pack through the first circuit 141, thereby achieving step-down charging of the battery pack. When the second circuit 142 is turned on, the motor controller is in a third control state so that the battery pack discharges through the motor controller to the motor coil 131; or the motor controller is in a fourth control state so that the motor coil 131 charges the battery pack through the second circuit 142, thereby achieving self-heating of the battery pack.

[0040] Moreover, the vehicle charging and discharging circuit of this application does not add any additional power devices, will not increase additional costs, and can reduce the size of the vehicle charging and discharging circuit.

[0041] In some embodiments, the number of cells in the first cell group 111 may be the same as or different from the number of cells in the second cell group 112, and this is not limited. Preferably, the voltage of the first cell group 111 is equal to the voltage of the second cell group 112. In this case, the series connection point between the first cell group 111 and the second cell group 112 is the midpoint of the battery pack's potential.

[0042] The neutral point of a motor, also known as the "zero point," refers to the common point of a star connection in a three-phase or multi-phase AC system.

[0043] In some embodiments, such as Figure 1 As shown, the first end of the first circuit 141 is adapted to connect to the positive terminal of the battery pack, the second end of the first circuit 141 is connected to the neutral point of the motor, and a first switch K1 is provided on the first circuit 141.

[0044] Specifically, when the first switch K1 is closed, the first circuit 141 is turned on. At this time, the motor controller can be in a first control state and connected to the charging pile so that the charging pile charges the battery pack sequentially through the motor controller, the motor coil 131, and the first circuit 141. Alternatively, the motor controller can be in a second control state so that the motor coil 131 charges the battery pack through the first circuit 141, thereby achieving step-down charging of the battery pack. When the first switch K1 is open, the first circuit 141 is disconnected, and step-down charging of the battery pack is no longer performed.

[0045] In some embodiments, such as Figure 1 As shown, the first end of the second circuit 142 is adapted to connect the series connection point between the first battery cell group 111 and the second battery cell group 112, the second end of the second circuit 142 is connected to the neutral point of the motor, and a second switch K2 is provided on the second circuit 142.

[0046] Specifically, when the second switch K2 is closed, the second circuit 142 is activated. At this time, the motor controller is in a third control state, allowing the battery pack to discharge through the motor controller to the motor coil 131, or the motor controller is in a fourth control state, allowing the motor coil 131 to charge the battery pack through the second circuit 142, thereby achieving self-heating of the battery pack. When the second switch K2 is open, the second circuit 142 is deactivated, and self-heating of the battery pack ceases.

[0047] In some embodiments, such as Figure 1 As shown, the first bus terminal of the motor controller is connected to the positive terminal of the battery pack through the positive bus circuit 151. A third switch K3 is provided on the positive bus circuit 151. The second bus terminal of the motor controller is connected to the negative terminal of the battery pack through the negative bus circuit 152. A fourth switch K4 is provided on the negative bus circuit 152.

[0048] In addition, such as Figure 1 As shown, a sixth switch K6 can be installed between the positive terminal of the charging pile and the first busbar of the motor controller, and a seventh switch K7 can be installed between the negative terminal of the charging pile and the second busbar of the motor controller.

[0049] Among them, such as Figure 2 As shown, during the step-down charging process, when both the motor coil 122 and the battery pack are being charged, the sixth switch K6 and the seventh switch K7 can be closed to make the vehicle charging and discharging circuit electrically connected to the charging pile. Secondly, the first switch K1 and the fourth switch K4 can be closed (the second switch K2 and the third switch K3 are in the open state), and the motor controller is put into the first control state to make the charging pile, the motor controller, the motor, the first circuit 141 and the battery pack connected to form a circuit. Then the charging pile can charge the motor coil 131 through the motor controller, and the charging energy can further charge the battery pack through the first circuit 141.

[0050] like Figure 3 As shown, during the step-down charging process, when the battery pack is charged through the motor coil 131, the sixth switch K6, the seventh switch K7, the first switch K1 and the fourth switch K4 remain closed, and the motor controller is in the second control state to form a circuit between the motor controller, the motor, the first circuit 141 and the battery pack. Thus, the motor coil 131 can charge the battery pack through the first circuit 141.

[0051] like Figure 4 As shown, during the self-heating process, when the battery pack discharges to the motor coil 131, the second switch K2, the third switch K3, and the fourth switch K4 can be closed (the first switch K1, the sixth switch K6, and the seventh switch K7 are in the open state), and the motor controller is put into the third control state so that the battery pack, the bus positive circuit 151, the motor controller, the motor, and the second circuit 142 are connected to form a loop, and then the battery pack can discharge to the motor coil 131 through the motor controller.

[0052] like Figure 5 As shown, during the self-heating process, when the motor coil 131 charges the battery pack, the second switch K2, the third switch K3 and the fourth switch K4 remain closed, and the motor controller is in the fourth control state so that the battery pack, the bus negative circuit 152, the motor controller, the motor and the second circuit 142 are connected to form a loop, so that the motor coil 131 can charge the battery pack through the second circuit 142.

[0053] In some embodiments, the motor controller includes a plurality of bridge arm assemblies connected in parallel between a first bus terminal and a second bus terminal. Each bridge arm assembly includes a first bridge group 121 and a second bridge group 122 connected in series. A first end of the first bridge group 121 is connected to the first bus terminal, a second end of the first bridge group 121 is connected to the first end of the second bridge group 122, and a second end of the second bridge group 122 is connected to the second bus terminal. The series connection point of the first bridge group 121 and the second bridge group 122 in each bridge arm assembly is connected to a coil of the motor.

[0054] Preferably, the first bridge group 121 includes a first switching transistor and a first diode, and the second bridge group 122 includes a second switching transistor and a second diode. The first end of the first switching transistor is connected to a first bus terminal, and the second end of the first switching transistor is connected to the first end of the second switching transistor. The second end of the second switching transistor and the anode of both the second diode are connected to a second bus terminal. The anode of the first diode is connected to the first end of the first switching transistor, and the cathode of the first diode is connected to the second end of the first switching transistor. The anode of the second diode is connected to the first end of the second switching transistor, and the cathode of the second diode is connected to the second end of the second switching transistor. The connection node is located on the connection path between the second end of the first switching transistor and the first end of the second switching transistor. Understandably, the first diode is connected in parallel between the first end and the second end of the first switching transistor, and the second diode is connected in parallel between the first end and the second end of the second switching transistor. The wire between the second end of the first switching transistor and the first end of the second switching transistor is connected to the coil of the motor. The first end can be the drain, and the second end can be the source.

[0055] Furthermore, the first bridge group 121 and the second bridge group 122 may include power electronic devices such as IGBT (Insulated Gate Bipolar Transistor), MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and HEMT (High Electron Mobility Transistor). The materials of the power electronic devices may be Si, SiC, GaN, etc., and there is no limitation on them.

[0056] This embodiment can achieve step-down charging or self-heating of the battery pack by controlling the on / off state of the bridge group in the motor controller. During step-down charging, the first circuit 141 is turned on, and the motor controller controls at least one bridge arm assembly to turn on the first bridge group 121 and disconnect the second bridge group 122, so that the charging pile charges the battery pack sequentially through the turned-on first bridge group 121, the motor coil 131, and the first circuit 141; or the motor controller controls at least one bridge arm assembly to turn on the second bridge group 122 and disconnect the first bridge group 121, so that the motor coil 131 charges the battery pack through the first circuit 141. During the self-heating process, when the second circuit 142 is turned on, the motor controller controls the first bridge group 121 in at least one bridge arm assembly to be turned on and the second bridge group 122 to be turned off, so that the first battery cell group 111 discharges to the motor coil 131 through the turned-on first bridge group 121; or the motor controller controls the second bridge group 122 in at least one bridge arm assembly to be turned on and the first bridge group 121 to be turned off, so that the motor coil 131 charges the second battery cell group 112 through the second circuit 142.

[0057] Taking a three-phase motor as an example, the motor controller includes three bridge arm assemblies. The series connection points of the first bridge group 121 and the second bridge group 122 in the three bridge arm assemblies are respectively connected to the three coils of the three-phase motor.

[0058] like Figure 2 As shown, during the step-down charging process, when both the motor coil 122 and the battery pack are being charged, the sixth switch K6 and the seventh switch K7 can be closed to make the vehicle charging and discharging circuit electrically connected to the charging pile. Secondly, the first switch K1 and the fourth switch K4 can be closed (the second switch K2 and the third switch K3 are in the open state), and the motor controller is in the first control state (that is, the motor controller controls the first bridge group 121 of one or more bridge arm assemblies to be turned on and the second bridge group 122 to be turned off), so that the charging pile, the first bridge group 121 of the motor controller, the motor, the first circuit 141 and the battery pack are connected to form a circuit. Then, the charging pile can charge the motor coil 131 through the first bridge group 121 of the motor controller, and the charging energy can further charge the battery pack through the first circuit 141.

[0059] like Figure 3As shown, during the step-down charging process, when the battery pack is charged through the motor coil 131, the sixth switch K6 and the seventh switch K7 are kept closed, and the motor controller is in the second control state (that is, the second bridge group 122 in one or more bridge arm assemblies is turned on and the first bridge group 121 is turned off by the motor controller). At the same time, the first switch K1 and the fourth switch K4 remain closed, and a circuit is formed between the second bridge group 122 of the motor controller, the motor, the first circuit 141 and the battery pack. Thus, the motor coil 131 can charge the battery pack through the first circuit 141.

[0060] In the above process, the motor controller controls the first bridge group 121 and the second bridge group 122 in the bridge arm assembly to alternately turn on and off, so that the charging and discharging of the motor coil 122 alternately cycle, thereby achieving the purpose of reducing the charging voltage.

[0061] like Figure 4 As shown, during the self-heating process, when the battery pack discharges to the motor coil 131, the second switch K2, the third switch K3, and the fourth switch K4 can be closed (the first switch K1, the sixth switch K6, and the seventh switch K7 are in the open state), and the motor controller is put into the third control state (that is, the motor controller controls the first bridge group 121 in one or more bridge arm assemblies to be turned on and the second bridge group 122 to be turned off), so that the first cell group 111, the bus positive circuit 151, the first bridge group 121 of the motor controller, the motor, and the second circuit 142 are connected to form a loop, and then the first cell group 111 can discharge to the motor coil 131 through the first bridge group 121 of the motor controller.

[0062] like Figure 5 As shown, during the self-heating process, when the motor coil 131 charges the battery pack, the second switch K2, the third switch K3, and the fourth switch K4 remain closed, and the motor controller is in the fourth control state (that is, the motor controller controls the second bridge group 122 in one or more bridge arm assemblies to be turned on and the first bridge group 121 to be turned off), so that the second battery cell group 112, the bus negative circuit 152, the second bridge group 122 of the motor controller, the motor, and the second circuit 142 are connected to form a loop, and then the motor coil 131 can charge the second battery cell group through the second circuit 142.

[0063] It should be noted that, Figure 4 and Figure 5Taking the example of the first battery cell group 111 discharging into the motor coil 122, and then the motor coil 122 charging the second battery cell group 112, the current released by the motor coil 122 generates heat across the resistance R of the second battery cell, thus heating the second battery cell group 112. Correspondingly, by controlling the switching on and off of the first bridge group 121 and the second bridge group 122 through the motor controller, it is also possible for the second battery cell group 112 to discharge into the motor coil 122, and then the motor coil 122 to charge the first battery cell group 111. In this process, the current released by the motor coil 122 generates heat across the resistance R of the first battery cell, thus heating the second battery cell group 112. For details, please refer to [link to relevant documentation]. Figure 6 and Figure 7 .

[0064] like Figure 6 As shown, during the self-heating process, when the battery pack discharges to the motor coil 131, the second switch K2, the third switch K3, and the fourth switch K4 can be closed (the first switch K1, the sixth switch K6, and the seventh switch K7 are in the open state), and the motor controller is in the third control state (at this time, the third control state means that the second bridge group 122 in one or more bridge arm assemblies is turned on and the first bridge group 121 is turned off by controlling the motor controller), so that the second cell group 112, the second circuit 142, the motor, the second bridge group 122 of the motor controller, and the negative bus circuit 152 are connected to form a loop, and then the second cell group 112 can discharge to the motor coil 131 through the second circuit 142.

[0065] like Figure 7 As shown, during the self-heating process, when the motor coil 131 charges the battery pack, the second switch K2, the third switch K3, and the fourth switch K4 remain closed, and the motor controller is in the fourth control state (at this time, the fourth control state means that the motor controller controls the first bridge group 121 in one or more bridge arm assemblies to be turned on and the second bridge group 122 to be turned off), so that the first cell group 111, the second circuit 142, the motor, the first bridge group 121 of the motor controller, and the positive circuit of the bus are connected to form a loop, and then the motor coil 131 can charge the first cell group 111 through the first bridge group 121 of the motor controller.

[0066] In the above process, the motor controller controls the first bridge group 121 and the second bridge group 122 in the bridge arm assembly to alternately turn on and off, so that after the first battery cell group 111 charges the motor coil 122, the motor coil 122 charges the second battery cell group 112, or after the second battery cell group 112 charges the motor coil 122, the motor coil 122 charges the first battery cell group 111. This alternation allows both the first battery cell group 111 and the second battery cell group 112 to achieve self-heating.

[0067] In some embodiments, such as Figure 1 As shown, the vehicle charging and discharging circuit also includes a capacitor C, which is connected in parallel between the first and second bus terminals. Understandably, the branch containing capacitor C can perform functions such as decoupling, filtering, and energy storage.

[0068] In some embodiments, such as Figure 1 As shown, the vehicle charging and discharging circuit also includes a third circuit. The first terminal of the third circuit is connected to the first circuit 141, and the second terminal of the third circuit is connected to the first bus terminal. A resistor R and a fifth switch K5 are connected in series on the third circuit. It can be understood that when the fifth switch K5 is closed, the resistor R can play a pre-charging role when charging the battery pack.

[0069] According to another aspect of this application, such as Figure 8 As shown, a vehicle 200 is provided, which includes a vehicle charging and discharging circuit 210.

[0070] Among them, the vehicle charging and discharging circuit 210 can be implemented as the vehicle charging and discharging circuit mentioned above, which can be referred to in the above description and will not be repeated here.

[0071] In summary, according to the vehicle charging and discharging circuit and vehicle of the embodiments of this application, when the first circuit is turned on, the motor controller is in a first control state and connected to the charging pile so that the charging pile charges the battery pack sequentially through the motor controller, the motor coil and the first circuit, or the motor controller is in a second control state so that the motor coil charges the battery pack through the first circuit to achieve step-down charging of the battery pack; when the second circuit is turned on, the motor controller is in a third control state so that the battery pack discharges through the motor controller to the motor coil, or the motor controller is in a fourth control state so that the motor coil charges the battery pack through the second circuit to achieve self-heating of the battery pack.

[0072] Moreover, the vehicle charging and discharging circuit of this application does not add any additional power devices, will not increase additional costs, and can reduce the size of the vehicle charging and discharging circuit.

[0073] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0074] Similarly, it should be understood that, in order to simplify this application and aid in understanding one or more aspects of the application, various features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, the point of application is that the corresponding technical problem can be solved with fewer features than all of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0075] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0076] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

Claims

1. A vehicle charging and discharging circuit, characterized in that, The vehicle charging and discharging circuit includes: First circuit; Second circuit; A motor, wherein the neutral point of the motor is adapted to be connected to the positive terminal of the battery pack via the first circuit, and the neutral point of the motor is also adapted to be connected to the series connection point between the first and second battery cell groups via the second circuit; and A motor controller, wherein a first bus terminal of the motor controller is adapted to be connected to the positive terminal of the battery pack, a second bus terminal of the motor controller is adapted to be connected to the negative terminal of the battery pack, and an output terminal of the motor controller is connected to the input terminal of the motor; in, When the first circuit is turned on, the motor controller is in a first control state and is adapted to connect to the charging pile so that the charging pile charges the battery pack sequentially through the motor controller, the coil of the motor and the first circuit; or the motor controller is in a second control state so that the coil of the motor charges the battery pack through the first circuit. When the second circuit is turned on, the motor controller is in a third control state, so that the battery pack discharges to the coil of the motor through the motor controller, or the motor controller is in a fourth control state, so that the coil of the motor charges the battery pack through the second circuit; The battery pack includes a first cell group and a second cell group connected in series.

2. The vehicle charging and discharging circuit as described in claim 1, characterized in that, The first end of the first circuit is adapted to be connected to the positive terminal of the battery pack, the second end of the first circuit is connected to the neutral point of the motor, and a first switch is provided on the first circuit.

3. The vehicle charging and discharging circuit as described in claim 1, characterized in that, The first end of the second circuit is adapted to connect the series connection point between the first battery cell group and the second battery cell group, the second end of the second circuit is connected to the neutral point of the motor, and a second switch is provided on the second circuit.

4. The vehicle charging and discharging circuit as described in claim 1, characterized in that, The motor controller includes multiple bridge arm assemblies connected in parallel between the first bus terminal and the second bus terminal. Each bridge arm assembly includes a first bridge group and a second bridge group connected in series. The first end of the first bridge group is connected to the first bus terminal, the second end of the first bridge group is connected to the first end of the second bridge group, and the second end of the second bridge group is connected to the second bus terminal. The series connection point of the first bridge group and the second bridge group in each bridge arm assembly is connected to one coil of the motor.

5. The vehicle charging and discharging circuit as described in claim 4, characterized in that, When the first circuit is turned on The motor controller controls at least one of the bridge arm assemblies to turn on the first bridge group and turn off the second bridge group, so that the charging pile charges the battery pack sequentially through the turned-on first bridge group, the motor coil and the first circuit; or The motor controller controls at least one of the bridge arm assemblies to turn on the second bridge group and turn off the first bridge group, so that the motor coils charge the battery pack through the first circuit.

6. The vehicle charging and discharging circuit as described in claim 4, characterized in that, When the second circuit is turned on The motor controller controls at least one of the bridge arm assemblies to turn on the first bridge group and turn off the second bridge group, so that the first cell group discharges to the coil of the motor through the turned-on first bridge group; or The motor controller controls at least one of the bridge arm assemblies to turn on the second bridge group and turn off the first bridge group, so that the motor coil charges the second battery cell group through the second circuit.

7. The vehicle charging and discharging circuit as described in claim 4, characterized in that, When the second circuit is turned on The motor controller controls at least one of the bridge arm assemblies to turn on the second bridge group and turn off the first bridge group, so that the second battery cell group discharges to the coil of the motor through the second circuit; or The motor controller controls at least one of the bridge arm assemblies to turn on the first bridge group and turn off the second bridge group, so that the motor coil charges the first cell group through the turned-on first bridge group.

8. The vehicle charging and discharging circuit as described in claim 4, characterized in that, Both the first bridge group and the second bridge group include insulated gate bipolar transistors.

9. The vehicle charging and discharging circuit as described in claim 1, characterized in that, The first bus terminal is connected to the positive terminal of the battery pack via a bus positive circuit, and a third switch is provided on the bus positive circuit. The second bus terminal is connected to the negative terminal of the battery pack via a bus negative circuit, and a fourth switch is provided on the bus negative circuit.

10. The vehicle charging and discharging circuit as described in claim 1, characterized in that, The vehicle charging and discharging circuit also includes a capacitor connected in parallel between the first bus terminal and the second bus terminal.

11. The vehicle charging and discharging circuit as described in claim 1, characterized in that, The vehicle charging and discharging circuit also includes a third circuit. The first end of the third circuit is connected to the first circuit, and the second end of the third circuit is connected to the first bus terminal. The third circuit is provided with a resistor and a fifth switch connected in series.

12. A vehicle, characterized in that, The vehicle includes a vehicle charging and discharging circuit as described in any one of claims 1 to 11.

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