Battery heating circuit, battery device, electric device and energy storage device

Abstract

The application provides a battery heating circuit, a battery device, a power utilization equipment and an energy storage equipment, and belongs to the technical field of batteries. The battery comprises a plurality of battery groups connected in parallel, each battery group comprising a first battery unit and a second battery unit connected in series. The battery heating circuit comprises a switching circuit and a first energy storage circuit. The first end and the second end of the switching circuit are connected with the positive electrode and the negative electrode of each battery group, respectively. The first end of the first energy storage circuit is connected with the switching circuit, and the second end of the first energy storage circuit is connected with the midpoint between the first battery unit and the second battery unit of each battery group, respectively. The first battery unit and the first energy storage circuit form a first heating loop, and the second battery unit and the first energy storage circuit form a second heating loop. The application realizes the heating of each battery group connected in parallel, improves the heating efficiency and the uniformity of heating at the same time.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery heating circuit, battery device, electrical equipment, and energy storage device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In low-temperature environments, battery charging efficiency is low. Therefore, how to improve battery charging efficiency in low-temperature environments is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in the background art. Therefore, one object of this application is to provide a battery heating circuit, battery device, electrical appliance, and energy storage device to improve the charging efficiency of batteries in low-temperature environments.

[0005] An embodiment of the first aspect of this application provides a battery heating circuit. The battery includes multiple battery packs connected in parallel, each battery pack including a first battery cell and a second battery cell connected in series. The battery heating circuit includes a switching circuit and a first energy storage circuit. A first terminal of the switching circuit is connected to the positive terminal of each battery pack, and a second terminal of the switching circuit is connected to the negative terminal of each battery pack. A first terminal of the first energy storage circuit is connected to the switching circuit, and a second terminal of the first energy storage circuit is connected to the midpoint between the first battery cell and the second battery cell of each battery pack. The switching circuit is configured to connect the first battery cell to the first energy storage circuit to form a first heating circuit, and to connect the second battery cell to the first energy storage circuit to form a second heating circuit.

[0006] In the technical solution of this application embodiment, the switching circuit is controlled to realize the switching between different heating circuits, thereby realizing energy exchange between the first battery unit and the second battery unit, and thus realizing the heating of each battery pack connected in parallel, improving heating efficiency and heating uniformity.

[0007] In some embodiments, a first terminal of the switching circuit is connected to a first connection point, and the positive terminal of each battery pack is connected to the first connection point via a first switch. A second terminal of the first energy storage circuit is connected to a second connection point, and the midpoint between the first and second battery cells of each battery pack is connected to the second connection point via a second switch. By controlling the first and second switches, only one battery pack can be heated at a time during the heating phase, thereby effectively utilizing the heating current and increasing the heating rate.

[0008] In some embodiments, the switching circuit includes at least one switching branch, with its two ends connected to a first connection point and the negative terminal of each battery pack, respectively. The switching branch includes a first switching element and a second switching element connected in series, with the midpoint between the first and second switching elements connected to a first terminal of the first energy storage circuit. Different heating circuits can be formed and switched between them using the first and second switching elements.

[0009] In some embodiments, there are multiple switching branches connected in parallel. The first energy storage circuit includes multiple first energy storage elements connected in parallel. These multiple first energy storage elements are connected one-to-one with the midpoint between the first and second switching elements of the multiple switching branches. By setting multiple corresponding first energy storage elements and multiple switching branches, multiple first heating circuits or multiple second heating circuits can be formed, thereby improving the heating efficiency of the battery.

[0010] In some embodiments, the first energy storage circuit further includes a second energy storage element, which is connected in series with a plurality of first energy storage elements that are connected in parallel. By adding a second energy storage element, the heating efficiency and reliability are improved.

[0011] In some embodiments, the first energy storage element and the second energy storage element are inductors. By configuring the first energy storage element and the second energy storage element as inductors, energy storage and release are achieved through inductance.

[0012] In some embodiments, the first energy storage circuit includes three first inductors connected in parallel, which are multiplexed from the three-phase inductors in the motor. By multiplexing the three-phase inductors in the motor to form the first energy storage circuit, the overall cost is reduced.

[0013] In some embodiments, the switching branch is a bridge arm, which includes an upper bridge arm and a lower bridge arm connected in series. The upper bridge arm is connected to the positive terminal of each battery pack, and the lower bridge arm is connected to the negative terminal of each battery pack. A first terminal of the first energy storage circuit is connected between the upper and lower bridge arms. The switching element of the upper bridge arm serves as a first switching element, and the switching element of the lower bridge arm serves as a second switching element. The bridge arm has a simple structure and is easy to control, which simplifies the circuit while improving the reliability of battery heating control.

[0014] In some embodiments, the battery heating circuit further includes a balancing branch. A balancing branch is provided between each pair of adjacent battery packs. In each pair of adjacent battery packs, a first end of the balancing branch is connected to the midpoint between the first and second battery cells of one pack, and a second end of the balancing branch is connected to the midpoint between the first and second battery cells of the other pack. By providing the balancing branch, the individual first and second battery cells are balanced after the battery heating process is complete.

[0015] In some embodiments, the battery heating circuit further includes a second energy storage circuit, wherein a first terminal of the second energy storage circuit is connected to the positive terminal of each battery pack, and a second terminal of the second energy storage circuit is connected to the negative terminal of each battery pack. By adding the second energy storage circuit, the energy transfer efficiency is improved, thereby further improving the battery heating efficiency. An embodiment of the second aspect of this application provides a battery device including a battery and the battery heating circuit of any of the above embodiments.

[0016] In some embodiments, the battery includes multiple battery packs connected in parallel, each battery pack including a first battery cell and a second battery cell connected in series.

[0017] An embodiment of the third aspect of this application provides an electrical device including a battery device as described in the above embodiments, the battery device being used to provide electrical energy.

[0018] An embodiment of the fourth aspect of this application provides an energy storage device, including a battery device as described in the above embodiments.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0021] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the battery heating circuit in some embodiments of this application;

[0023] Figure 3 This is one of the schematic diagrams of the current path of the battery heating circuit in the first heating stage according to some embodiments of this application;

[0024] Figure 4 This is a second schematic diagram of the current path of the battery heating circuit in the first heating stage according to some embodiments of this application;

[0025] Figure 5 This is one of the schematic diagrams of the current path of the battery heating circuit in the second heating stage according to some embodiments of this application;

[0026] Figure 6 This is a second schematic diagram of the current path of the battery heating circuit in the second heating stage according to some embodiments of this application;

[0027] Figure 7 This is the third schematic diagram of the current path of the battery heating circuit in the first heating stage of some embodiments of this application;

[0028] Figure 8 This is the fourth schematic diagram of the current path of the battery heating circuit in the first heating stage of some embodiments of this application;

[0029] Figure 9 This is the third schematic diagram of the current path of the battery heating circuit in the second heating stage according to some embodiments of this application;

[0030] Figure 10 This is the fourth schematic diagram of the current path of the battery heating circuit in the second heating stage of some embodiments of this application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1000, vehicles;

[0033] 100. Battery; 200. Vehicle controller; 300. Motor;

[0034] 10. Battery pack; 11. First battery cell; 12. Second battery cell;

[0035] 20. Switching circuit; 21. Switching branch;

[0036] 30. First energy storage circuit;

[0037] 40. Balanced branch;

[0038] 50. Second energy storage circuit. Detailed Implementation

[0039] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0041] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0042] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0043] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0044] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0045] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0046] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical 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 refer to 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0047] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0048] In low-temperature environments, the fluidity of the battery electrolyte decreases, which slows down the movement of ions and results in lower charging efficiency, leading to longer charging times and thus affecting battery performance.

[0049] In some cases, battery charging efficiency can be improved by increasing the battery temperature. This can be achieved by using an external heating device, such as a thermistor (Positive Temperature Coefficient, PTC). However, this heating method relies on heat transfer, resulting in relatively low heating efficiency and uneven temperature distribution between the battery's exterior and interior.

[0050] Based on the above considerations, this application provides a battery heating circuit, a battery device, an electrical appliance, and an energy storage device. The battery includes multiple battery packs connected in parallel, and each battery pack includes a first battery cell and a second battery cell connected in series. The battery heating circuit includes a switching circuit and a first energy storage circuit. A first terminal of the switching circuit is connected to the positive terminal of each battery pack, and a second terminal of the switching circuit is connected to the negative terminal of each battery pack. A first terminal of the first energy storage circuit is connected to the switching circuit, and a second terminal of the first energy storage circuit is connected to the midpoint between the first and second battery cells of each battery pack. The switching circuit is configured to connect the first battery cell to the first energy storage circuit to form a first heating circuit, and to connect the second battery cell to the first energy storage circuit to form a second heating circuit.

[0051] By controlling the switching circuit, the switching between different heating circuits is realized, thereby realizing energy exchange between the first battery unit and the second battery unit, and thus realizing the heating of each battery pack in parallel, improving heating efficiency and heating uniformity.

[0052] The battery heating circuit disclosed in this application can be used, but is not limited to, for heating batteries in electrical equipment such as vehicles, ships, or aircraft, as well as in energy storage devices. This helps improve battery charging efficiency in low-temperature environments.

[0053] Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0054] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0055] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle according to some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a vehicle controller 200 and a motor 300. The vehicle controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0056] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0057] Combination Figures 2 to 6 As shown, Figure 2 This is a schematic diagram of the battery heating circuit in some embodiments of this application; Figure 3 This is one of the schematic diagrams of the current path of the battery heating circuit in the first heating stage according to some embodiments of this application; Figure 4 This is a second schematic diagram of the current path of the battery heating circuit in the first heating stage according to some embodiments of this application; Figure 5 This is one of the schematic diagrams of the current path of the battery heating circuit in the second heating stage according to some embodiments of this application; Figure 6 This is a second schematic diagram of the current path of the battery heating circuit in the second heating stage according to some embodiments of this application.

[0058] This application provides a battery heating circuit. The battery includes multiple battery packs 10 connected in parallel, each battery pack 10 including a first battery cell 11 and a second battery cell 12 connected in series. The battery heating circuit includes a switching circuit 20 and a first energy storage circuit 30. A first terminal of the switching circuit 20 is connected to the positive terminal of each battery pack 10, and a second terminal of the switching circuit 20 is connected to the negative terminal of each battery pack 10. A first terminal of the first energy storage circuit 30 is connected to the switching circuit 20, and a second terminal of the first energy storage circuit 30 is connected to the midpoint between the first battery cell 11 and the second battery cell 12 of each battery pack 10. The switching circuit 20 is configured to connect the first battery cell 11 to the first energy storage circuit 30 to form a first heating circuit, and to connect the second battery cell 12 to the first energy storage circuit 30 to form a second heating circuit.

[0059] Each battery pack 10 includes a first battery cell 11 and a second battery cell 12 connected in series. The series connection can be such that the positive terminal of the first battery cell 11 is connected to the negative terminal of the second battery cell 12, or vice versa. In some examples, such as... Figures 2 to 4 As shown, the negative terminal of the first battery unit 11 is connected to the positive terminal of the second battery unit 12. The positive terminal of the battery pack 10 is the positive terminal of the first battery unit 11, and the negative terminal of the battery pack 10 is the negative terminal of the second battery unit 12. The midpoint between the first battery unit 11 and the second battery unit 12 is the connection point between the negative terminal of the first battery unit 11 and the positive terminal of the second battery unit 12.

[0060] The switching circuit 20 is a circuit that controls the on / off state of current. Specifically, it can control the on / off state of the switching element to realize the conduction or disconnection of current in the circuit.

[0061] The first energy storage circuit 30 is a circuit that stores energy and releases it when needed. In some examples, external electrical energy is input to the first energy storage circuit 30 for storage, and the stored energy is released externally in the form of electrical energy when needed. The first energy storage circuit 30 includes energy storage elements, which can be capacitors or inductors.

[0062] The switching circuit 20 may include a first node C1, a second node C2, and a third node C3 interconnected by switching elements. The first node C1 may be connected to the positive terminal of the battery pack 10, the second node C2 may be connected to the negative terminal of the battery pack 10, and the third node C3 may be connected to the first terminal of the first energy storage circuit 30. The first node C1 may be a node between the switching circuit 20 and the positive terminal of the battery pack 10, the second node C2 may be a node between the switching circuit 20 and the negative terminal of the battery pack 10, and the third node C3 may be a node between the first energy storage circuit 30 and the switching circuit 20.

[0063] The first node C1, the second node C2, and the third node C3 are interconnected via a switching element. That is, any two of the first node C1, the second node C2, and the third node C3 can be connected via a switching element. Through the switching circuit 20, the first energy storage circuit 30 can form a circuit with either the first battery unit 11 or the second battery unit 12. For example, the positive terminal of the first battery unit 11 is connected to the first node C1, and the negative terminal of the second battery unit 12 is connected to the second node C2. When the first node C1 and the third node C3 are both connected, the first energy storage circuit 30 and the first battery unit 11 form a first heating circuit. When the second node C2 and the third node C3 are both connected, the first energy storage circuit 30 and the second battery unit 12 form a second heating circuit.

[0064] In some embodiments, the on / off state of the switching elements in the switching circuit 20 can be controlled by a controller. The controller may include, but is not limited to, the controller in a vehicle's microcontroller unit (MCU) or a battery management system (BMS).

[0065] In some embodiments, a temperature sensor may also be provided in the battery to obtain the temperature of the first battery cell 11 and the second battery cell 12 of each battery pack 10. The temperature sensor is communicatively connected to the BMS, and the controller in the BMS can receive the temperature information of the first battery cell 11 and the second battery cell 12 detected by the temperature sensor. If the temperature of at least one of the first battery cell 11 and the second battery cell 12 in all battery packs 10 is lower than a preset temperature, the controller can control the switching circuit 20 to switch between the first heating circuit and the second heating circuit, thereby forming a first heating stage or a second heating stage.

[0066] like Figure 3 and Figure 4 As shown, the first heating stage includes charging the first battery cell to the first energy storage circuit and charging the second battery cell from the first energy storage circuit, thereby achieving battery heating through energy transfer from the first battery cell to the second battery cell. Figure 3 As shown, the first node and the third node are connected, forming a first heating circuit with the first battery unit 11 and the first energy storage circuit 30. The first battery unit 11 charges the first energy storage circuit 30, and the first energy storage circuit 30 stores energy. Heating of the first battery unit 11 is achieved through the discharge of the first battery unit 11. Figure 4As shown, the second node and the third node are connected, and the second battery unit 12 and the first energy storage circuit 30 form a second heating circuit. Since the first energy storage circuit 30 stores energy in the first heating circuit, the first energy storage circuit 30 can charge the second battery unit 12 in the second heating circuit, thereby heating the second battery unit 12 by charging the second battery unit 12.

[0067] like Figure 5 and Figure 6 As shown, the second heating stage includes charging the first energy storage circuit from the second battery cell and charging the first battery cell from the first energy storage circuit, thereby achieving battery heating through energy transfer from the second battery cell to the first battery cell. Figure 5 As shown, the second node C2 and the third node C3 are connected, and the second battery unit 12 and the first energy storage circuit 30 form a second heating circuit. The second battery unit 12 charges the first energy storage circuit 30, and the first energy storage circuit 30 stores energy. Thus, the second battery unit 12 is heated by discharging. Figure 6 As shown, the first node C1 and the third node C3 are connected, and the first battery unit 11 and the first energy storage circuit 30 form a first heating circuit. Since the first energy storage circuit 30 stores energy in the second heating circuit, the first energy storage circuit 30 can charge the first battery unit 11 in the first heating circuit, thereby heating the first battery unit 11 through charging.

[0068] In some embodiments, the first heating stage and the second heating stage can be controlled by the controller to proceed sequentially, so that while the energy exchange between the first battery unit 11 and the second battery unit 12 is used to heat the battery, the energy balance between the first battery unit 11 and the second battery unit 12 is maintained.

[0069] By controlling the switching circuit 20, the switching between different heating circuits is realized, thereby realizing energy exchange between the first battery unit 11 and the second battery unit 12, and thus realizing the heating of each battery pack in parallel, improving heating efficiency and heating uniformity.

[0070] like Figures 2 to 6 As shown, according to some embodiments of this application, the first terminal of the switching circuit 20 is connected to the first connection point P1, and the positive terminal of each battery pack 10 is connected to the first connection point P1 through a first switch (K4, K5, K6). The second terminal of the first energy storage circuit 30 is connected to the second connection point P2, and the midpoint between the first battery cell 11 and the second battery cell 12 of each battery pack 10 is connected to the second connection point P2 through a second switch (K9, K8, K7).

[0071] The first switches (K4, K5, K6) are components used to control the on / off state between the positive terminal of battery pack 10 and the first connection point P1. The second switches (K9, K8, K7) are components used to control the on / off state between the midpoint between the first battery cell 11 and the second battery cell 12 and the second connection point P2. In some examples, the first and second switches can be connected to a controller signal, and the controller controls the on / off state of the first and second switches.

[0072] Each battery pack 10 corresponds to one first switch and one second switch, meaning multiple first switches and second switches are configured in a one-to-one correspondence. For example, first switch K4 corresponds to second switch K9, first switch K5 corresponds to second switch K8, and first switch K6 corresponds to second switch K7. By closing the first switch and the corresponding second switch, the corresponding battery pack 10 is connected to the switching circuit 20 and the first energy storage circuit 30, allowing heating of the battery pack 10. By opening the first switch and the corresponding second switch, the corresponding battery pack 10 is disconnected from the switching circuit 20 and the first energy storage circuit 30, preventing heating of the battery pack.

[0073] Controlling multiple battery packs 10 to sequentially enter the heating phase for battery heating can be understood as follows: each battery pack 10 can be heated sequentially in a certain order. That is, during the heating phase, only one battery pack 10 is heated at a time, meaning only one battery pack 10 is connected to the switching circuit 20 and the first energy storage circuit 30. While one battery pack 10 is in the heating phase, the remaining battery packs 10 are in the non-heating phase, until all battery packs 10 have completed heating.

[0074] Since only one battery pack 10 is heated at a time, the heating current will only flow in one battery pack 10 and will not be distributed to other battery packs 10, thus increasing the heating rate.

[0075] By controlling the first and second switches, the corresponding battery pack 10 can be connected or disconnected from the switching circuit 20 and the first energy storage circuit 30, thereby achieving heating of only one battery pack 10 at a time, effectively utilizing the heating current, and thus increasing the heating rate.

[0076] like Figures 2 to 6 As shown, according to some embodiments of this application, the switching circuit 20 includes at least one switching branch 21, with both ends of the switching branch 21 connected to a first connection point P1 and the negative terminal of each battery pack 10, respectively. The switching branch 21 includes a first switching element and a second switching element connected in series, with the midpoint between the first switching element and the second switching element connected to a first terminal of the first energy storage circuit 30.

[0077] The first switching element is located between the first node C1 and the third node C3, and is used to control the on / off state between the first node C1 and the third node C3. The second switching element is located between the second node C2 and the third node C3, and is used to control the on / off state between the second node C2 and the third node C3.

[0078] With the cooperation of the first and second switching elements, different heating circuits can be formed and switched between different heating circuits.

[0079] In some embodiments, the switching branch can be a bridge arm, which includes an upper bridge arm and a lower bridge arm connected in series. The switching element of the upper bridge arm is a first switching element, and the switching element of the lower bridge arm is a second switching element. The switching element of the upper bridge arm can be an upper bridge arm switch V1, and the switching element of the lower bridge arm can be a lower bridge arm switch V2. By turning the upper bridge arm switch V1 on / off, the upper bridge arm can be turned on / off; by turning the lower bridge arm switch V2 on / off, the lower bridge arm can be turned on / off.

[0080] The types of upper bridge arm switching transistor V1 and lower bridge arm switching transistor V2 include, but are not limited to, MOS transistors (Metal-Oxide-Semiconductor Field-Effect Transistors), IGBT transistors (Insulated-Gate Bipolar Transistors), or relays, etc., which are components capable of controlling the on and off of the circuit.

[0081] In some embodiments, the first energy storage circuit includes an inductor, with a first freewheeling diode D1 corresponding to the upper bridge arm switch V1 and a second freewheeling diode D2 corresponding to the lower bridge arm switch V2. When the upper bridge arm switches from on to off, current can flow through the first freewheeling diode D1, ensuring a constant current flow through the inductor. Similarly, when the lower bridge arm switches from on to off, current can flow through the second freewheeling diode D2. Thus, throughout the first and second heating stages, current consistently flows through the inductor, resulting in a small rate of change of current through the inductor and maintaining a low frequency of current flowing through the inductor, achieving low-frequency heating.

[0082] Different heating circuits can be formed and switched between different heating circuits by means of the first and second switching elements.

[0083] like Figures 2 to 6As shown, according to some embodiments of this application, there are multiple switch branches 21, and the multiple switch branches 21 are connected in parallel. The first energy storage circuit 30 includes multiple first energy storage elements connected in parallel. The multiple first energy storage elements are connected one-to-one to the midpoint between the first switch elements and the second switch elements of the multiple switch branches 21.

[0084] The first end of each first energy storage element is connected to the midpoint between the first and second switching elements of the corresponding switching branch. Multiple first energy storage elements can form multiple first heating circuits and multiple second heating circuits.

[0085] In some embodiments, the number of switch branches 21 can be two, three or more. The number of switch branches 21 can be adjusted according to different heating requirements to achieve a better heating effect.

[0086] The first energy storage element may include, but is not limited to, inductors or capacitors and other elements capable of storing energy.

[0087] By setting up multiple first energy storage elements and multiple switch branches 21 in a one-to-one correspondence, multiple first heating circuits or multiple second heating circuits can be formed, thereby improving the heating efficiency of the battery.

[0088] like Figures 2 to 6 As shown, according to some embodiments of this application, the first energy storage circuit 30 further includes a second energy storage element, which is connected in series with a plurality of first energy storage elements that are connected in parallel.

[0089] The second energy storage element and multiple first energy storage elements together constitute the first energy storage circuit 30, thereby enabling the storage and release of electrical energy.

[0090] In some embodiments, the first energy storage element is a first inductor L1, and the second energy storage element is a second inductor L2.

[0091] By adding a second energy storage element, the heating efficiency and reliability were improved.

[0092] like Figures 2 to 6 As shown, according to some embodiments of this application, the first energy storage element and the second energy storage element are inductors.

[0093] An inductor is an electronic component that can convert electrical energy into magnetic energy and store it, and can release the magnetic energy through a circuit.

[0094] In some embodiments, such as Figure 2 As shown, three first inductors L1 are connected in parallel and then connected in series with one second inductor L2.

[0095] By configuring the first and second energy storage elements as inductors, energy storage and release are achieved through inductors.

[0096] like Figures 2 to 6 As shown, according to some embodiments of this application, the first energy storage circuit 30 includes three first inductors L1 connected in parallel, which are multiplexed from the three-phase inductors in the motor.

[0097] The three first inductors L1 correspond to the three bridge arms. When heating the vehicle's battery, the vehicle includes a motor. The three bridge arms can reuse the three-phase bridge arms of the motor, and the three first inductors L1 can reuse the three-phase inductors of the motor. That is, the existing motor in the vehicle can be used to heat the battery without the need to set up additional inductors for heating, thus reducing costs.

[0098] By reusing the three-phase inductors in the motor to form the first energy storage circuit 30, the overall cost is reduced.

[0099] like Figures 2 to 6 As shown, according to some embodiments of this application, the switch branch 21 is a bridge arm, which includes an upper bridge arm and a lower bridge arm connected in series. The upper bridge arm is connected to the positive terminal of each battery pack 10, and the lower bridge arm is connected to the negative terminal of each battery pack 10. The first terminal of the first energy storage circuit 30 is connected between the upper bridge arm and the lower bridge arm. The switching element of the upper bridge arm serves as a first switching element, and the switching element of the lower bridge arm serves as a second switching element.

[0100] Under the control of the corresponding switching elements of the upper and lower bridge arms, different heating circuits can be formed to realize the energy transfer between the first battery cell 11 and the second battery cell 12. Specific details can be found in the descriptions of the above embodiments, and will not be repeated below.

[0101] By configuring the switch branch 21 as a bridge arm, the structure of the bridge arm is simple and easy to control, which simplifies the circuit and improves the reliability of battery heating control.

[0102] like Figures 2 to 6 As shown, according to some embodiments of this application, the battery heating circuit further includes a balancing branch 40. A balancing branch is provided between each of two adjacent battery packs. In the two adjacent battery packs, the first end of the balancing branch 40 is connected to the midpoint between the first battery cell 11 and the second battery cell 12 of one of them, and the second end of the balancing branch 40 is connected to the midpoint between the first battery cell 11 and the second battery cell 12 of the other.

[0103] The balancing branch 40 is configured to disconnect during battery heating and connect after battery heating is complete. Each pair of adjacent battery packs 10 has one balancing branch 40, so the number of balancing branches 40 is equal to the number of battery packs minus one.

[0104] During the process of heating each battery pack 10 in sequence, energy transfer is achieved between the first battery unit 11 and the second battery unit 12. After heating is completed, there may be an imbalance of electrical energy between the first battery unit 11 and the second battery unit 12 of each battery pack 10.

[0105] The balancing branch 40 is a circuit used to balance the voltages of each first battery cell 11 and each second battery cell 12 so that the voltages of each first battery cell 11 and each second battery cell 12 can be kept approximately the same.

[0106] When the battery is in the heating stage, all equalization branches 40 are disconnected. After the battery has finished heating, all equalization branches 40 are turned on. At this time, all first battery cells 11 are connected in parallel and all second battery cells 12 are connected in parallel, thereby balancing each first battery cell 11 and each second battery cell 12.

[0107] In some embodiments, when the BMS detects that the balancing current is less than a first threshold and the voltage difference is less than a second threshold, it disconnects all balancing branches 40 to enable normal battery use.

[0108] In some embodiments, the balancing branch 40 includes a switch K11 connected in series and a resistive load R. The resistive load R is used to alleviate the problem of large current caused by the large voltage difference of the battery cells before balancing. The resistive load R can be a heating resistive element, specifically a PTC, so that the heat generated by heating the resistive element during the balancing process can be utilized.

[0109] By setting up the equalization branch 40, the first battery cell 11 and the second battery cell 12 are equalized after the battery heating is completed.

[0110] Combination Figures 7 to 10 As shown, according to some embodiments of this application, the battery heating circuit further includes a second energy storage circuit 50, the first end of which is connected to the positive terminal of each battery pack 10, and the second end of which is connected to the negative terminal of each battery pack 10.

[0111] The second energy storage circuit 50 is a circuit that stores energy and releases it when needed. In some examples, external electrical energy is input to the second energy storage circuit 50 for storage, and the stored energy is released externally in the form of electrical energy when needed. The second energy storage circuit 50 includes an energy storage element, which can be a capacitor or an inductor. If the energy storage element of the first energy storage circuit 30 is an inductor, the energy storage element of the second energy storage circuit 50 is a capacitor.

[0112] The second energy storage circuit 50 is connected in parallel to both ends of the battery, that is, the first end of the second energy storage circuit 50 is connected to the first node C1, and the second end of the second energy storage circuit 50 is connected to the second node C2.

[0113] During the first heating stage.

[0114] like Figure 7 As shown, when the second node C2 and the third node C3 are conducting, the second battery unit 12 forms a second heating circuit with the first energy storage circuit 30, while the first battery unit 11 can also form a circuit with the second energy storage circuit 50. Therefore, the first battery unit 11 can charge the second energy storage circuit 50, and the second energy storage circuit 50 stores energy, thereby heating the first battery unit 11 through discharge. Simultaneously, the first energy storage circuit 30 can also charge the second battery unit 12; that is, the charging of the second energy storage circuit 50 by the first battery unit 11 and the charging of the second battery unit 12 by the first energy storage circuit 30 are performed simultaneously. In other words, current always flows through the first battery unit 11 and the second battery unit 12, which helps maintain the stability of the current flowing through the first battery unit 11 and the second battery unit 12, improving the heating efficiency of the battery while making the performance of the first battery unit 11 and the second battery unit 12 more stable. Among these, in Figure 7 The solid line with arrows indicates the current path of the first battery unit 11 charging the second energy storage circuit 50, and the dashed line with arrows indicates the current path of the first energy storage circuit 30 charging the second battery unit 12.

[0115] like Figure 8 As shown, when the first node C1 and the third node C3 are conducting, while the first battery unit 11 forms a first heating circuit with the first energy storage circuit 30, the second battery unit 12 can also form a circuit with the second energy storage circuit 50. Therefore, the second energy storage circuit 50 can charge the second battery unit 12, thereby heating the second battery unit 12 through charging. Simultaneously, the first battery unit 11 can also charge the first energy storage circuit 30; that is, the second energy storage circuit 50 charging the second battery unit 12 and the first battery unit 11 charging the first energy storage circuit 30 are performed simultaneously. In other words, current always flows through the first battery unit 11 and the second battery unit 12, which helps maintain the stability of the current flowing through the first battery unit 11 and the second battery unit 12, improving the heating efficiency of the battery while making the performance of the first battery unit 11 and the second battery unit 12 more stable. Among these, in Figure 8 The solid line with arrows indicates the current path of the second energy storage circuit 50 charging the second battery unit 12, and the dashed line with arrows indicates the current path of the first battery unit 11 charging the first energy storage circuit 30.

[0116] That is, during the first heating stage, the second energy storage circuit 50 enables the transfer of some electrical energy from the first battery cell 11 to the second battery cell 12.

[0117] In the second heating stage.

[0118] like Figure 9 As shown, when the first node C1 and the third node C3 are conducting, while the first battery unit 11 forms a first heating circuit with the first energy storage circuit 30, the second battery unit 12 can also form a circuit with the second energy storage circuit 50. Therefore, the second battery unit 12 can charge the second energy storage circuit 50, thereby achieving heating of the second battery unit 12 through its discharge. Simultaneously, the first energy storage circuit 30 can also charge the first battery unit 11; that is, the second battery unit 12 charging the second energy storage circuit 50 and the first energy storage circuit 30 charging the first battery unit 11 are performed simultaneously. In other words, current always flows through the first battery unit 11 and the second battery unit 12, which helps maintain the stability of the current flowing through them, improving the heating efficiency of the batteries and making the performance of the first battery unit 11 and the second battery unit 12 more stable. Among these, in Figure 9 The solid line with arrows indicates the current path of the second battery unit 12 charging the second energy storage circuit 50, and the dashed line with arrows indicates the current path of the first energy storage circuit 30 charging the first battery unit 11.

[0119] like Figure 10 As shown, when the second node C2 and the third node C3 are connected, while the second battery unit 12 forms a first heating circuit with the first energy storage circuit 30, the first battery unit 11 can also form a circuit with the second energy storage circuit 50. Therefore, the second energy storage circuit 50 can charge the first battery unit 11, thus heating the first battery unit 11 through charging. Simultaneously, the second battery unit 12 can also charge the first energy storage circuit 30; that is, the second energy storage circuit 50 charging the first battery unit 11 and the second battery unit 12 charging the first energy storage circuit 30 are performed simultaneously. In other words, current always flows through the first battery unit 11 and the second battery unit 12, which helps maintain the stability of the current flowing through the first battery unit 11 and the second battery unit 12, improving the heating efficiency of the battery and making the performance of the first battery unit 11 and the second battery unit 12 more stable. Among these, in Figure 10 The solid line with an arrow indicates the current path of the second energy storage circuit 50 for charging the first battery unit 11, and the dashed line with an arrow indicates the current path of the second battery unit 12 for charging the first energy storage circuit 30.

[0120] That is, in the second heating stage, the second energy storage circuit 50 realizes the transfer of part of the electrical energy in the second battery cell 12 to the first battery cell 11.

[0121] The first heating stage and the second heating stage are performed sequentially to achieve energy exchange between the first battery unit 11 and the second battery unit 12.

[0122] By adding a second energy storage circuit 50, in conjunction with the first energy storage circuit 30, the efficiency of energy transfer is improved, thereby further improving the heating efficiency of the battery.

[0123] like Figures 2 to 10 As shown, according to some embodiments of this application, the first energy storage circuit 30 includes at least one inductor, and the second energy storage circuit 50 includes a capacitor.

[0124] Both inductors and capacitors can be used as energy storage elements for energy storage.

[0125] Through the cooperation of inductors and capacitors, energy exchange is achieved between the first battery cell 11 and the second battery cell 12.

[0126] An embodiment of the second aspect of this application provides a battery device, including a battery and a battery heating circuit of any of the above embodiments. The battery heating circuit is connected to the battery and is used to heat the battery.

[0127] The battery device has the beneficial effects of the battery heating circuit provided in the embodiments of this application. For details, please refer to the specific description of the battery heating circuit in the above embodiments, which will not be repeated here.

[0128] According to some embodiments of this application, the battery includes multiple battery packs connected in parallel, each battery pack including a first battery cell and a second battery cell connected in series.

[0129] An embodiment of the third aspect of this application provides an electrical device including a battery device as described in the above embodiments, the battery device being used to provide electrical energy.

[0130] The electrical equipment has the beneficial effects of the battery device provided in the embodiments of this application. For details, please refer to the above description of the battery device, which will not be repeated here.

[0131] An embodiment of the fourth aspect of this application provides an energy storage device, including a battery device as described in the above embodiments.

[0132] The energy storage device has the beneficial effects of the battery device provided in the embodiments of this application. For details, please refer to the above description of the battery device, which will not be repeated here.

[0133] The following is combined Figures 2 to 10 The embodiments of this application will be described in further detail.

[0134] The battery includes three battery packs 10 connected in parallel, each battery pack 10 including a first battery cell 11 and a second battery cell 12 connected in series.

[0135] The battery heating circuit includes a switching circuit 20, a first energy storage circuit 30, and an equalization branch 40.

[0136] The first terminal of the switching circuit 20 is connected to the positive terminal of each battery pack 10, and the second terminal of the switching circuit 20 is connected to the negative terminal of each battery pack 10. The switching circuit 20 includes three bridge arms, each of which includes an upper bridge arm and a lower bridge arm connected in series.

[0137] The first energy storage circuit 30 includes three first inductors L1 connected in parallel, and a second inductor L2 connected in series with the three first inductors L1. The first terminal of the first energy storage circuit 30 is connected to the midpoint between the upper bridge arm and the lower bridge arm, and the second terminal of the first energy storage circuit 30 is connected to the midpoint between the first battery cell 11 and the second battery cell 12 of each battery pack 10.

[0138] Two equalization branches 40 are provided. In two adjacent battery packs 110, the first end of the equalization branch 40 is connected to the midpoint of the first battery cell 11 and the second battery cell 12 of one of them, and the second end of the equalization branch 40 is connected to the midpoint of the first battery cell 11 and the second battery cell 12 of the other. The equalization branch 40 includes a switch K11 and a resistive load R.

[0139] When battery heating is required, the heating process involves heating the first battery pack 10, the second battery pack 10, and the third battery pack 10 sequentially and individually. During the heating process, both equalization branches are disconnected.

[0140] During the heating process of each battery pack 10, a first heating stage is first performed to transfer energy from the first battery cell 11 to the second battery cell 12. Then, a second heating stage is performed to transfer energy from the second battery cell 12 to the first battery cell 11.

[0141] After all the battery packs 10 have been heated, the two equalization branches 40 are turned on to equalize the three first battery cells 11 and the three second battery cells 12.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not 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. These 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, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery heating circuit, characterized in that, The battery comprises multiple battery packs connected in parallel, each battery pack (10) including a first battery cell (11) and a second battery cell (12) connected in series; the battery heating circuit includes: A switching circuit (20) is provided, wherein the first end of the switching circuit (20) is connected to the positive terminal of each battery pack (10), and the second end of the switching circuit (20) is connected to the negative terminal of each battery pack (10). A first energy storage circuit (30) is connected at its first end to the switching circuit (20), and at its second end to the midpoint between the first battery cell (11) and the second battery cell (12) of each battery pack (10). The switching circuit is configured to connect the first battery cell (11) to the first energy storage circuit (30) to form a first heating circuit, and to connect the second battery cell (12) to the first energy storage circuit (30) to form a second heating circuit.

2. The battery heating circuit according to claim 1, characterized in that, The first end of the switching circuit (20) is connected to the first connection point (P1), and the positive terminal of each battery pack (10) is connected to the first connection point (P1) through a first switch (K4; K5; K6); The second end of the first energy storage circuit (30) is connected to the second connection point (P2), and the midpoint between the first battery cell (11) and the second battery cell (12) of each battery pack (10) is connected to the second connection point (P2) through a second switch (K9; K8; K7).

3. The battery heating circuit according to claim 2, characterized in that, The switching circuit (20) includes at least one switching branch (21), and the two ends of the switching branch (21) are respectively connected to the first connection point (P1) and the negative terminal of each battery pack (10); The switch branch (21) includes a first switch element and a second switch element connected in series, and the midpoint between the first switch element and the second switch element is connected to the first end of the first energy storage circuit (30).

4. The battery heating circuit according to claim 3, characterized in that, The number of the switch branches (21) is multiple, and the multiple switch branches (21) are connected in parallel. The first energy storage circuit (30) includes multiple first energy storage elements connected in parallel. The multiple first energy storage elements are connected one-to-one to the midpoint between the first switch element and the second switch element of the multiple switch branches (21).

5. The battery heating circuit according to claim 4, characterized in that, The first energy storage circuit (30) further includes a second energy storage element, which is connected in series with a plurality of the first energy storage elements connected in parallel.

6. The battery heating circuit according to claim 5, characterized in that, The first energy storage element and the second energy storage element are inductors.

7. The battery heating circuit according to claim 4, characterized in that, The first energy storage circuit (30) includes three first inductors (L1) connected in parallel, which are multiplexed from the three-phase inductors in the motor.

8. The battery heating circuit according to claim 3, characterized in that, The switch branch (21) is a bridge arm, which includes an upper bridge arm and a lower bridge arm connected in series. The switch element of the upper bridge arm serves as the first switch element, and the switch element of the lower bridge arm serves as the second switch element.

9. The battery heating circuit according to any one of claims 1-8, characterized in that, The battery heating circuit further includes: a balancing branch (40); The equalization branch is provided between each of the two adjacent battery packs; in the two adjacent battery packs, one end of the equalization branch is connected to the midpoint between the first battery cell (11) and the second battery cell (12) of one of them, and the other end of the equalization branch (40) is connected to the midpoint between the first battery cell (11) and the second battery cell (12) of the other.

10. The battery heating circuit according to any one of claims 1-8, characterized in that, The battery heating circuit also includes: The second energy storage circuit (50) has its first end connected to the positive terminal of each of the battery packs (10) and its second end connected to the negative terminal of each of the battery packs (10).

11. The battery heating circuit according to claim 10, characterized in that, The first energy storage circuit (30) includes at least one inductor, and the second energy storage circuit (50) includes a capacitor.

12. A battery device, characterized in that, It includes a battery and a battery heating circuit as described in any one of claims 1-11; the battery heating circuit is connected to the battery and is used to heat the battery.

13. The battery device according to claim 12, characterized in that, The battery comprises multiple battery packs connected in parallel, and each battery pack includes a first battery cell and a second battery cell connected in series.

14. An electrical appliance, characterized in that, The electrical device includes a battery device as described in claim 12 or 13, the battery device being used to provide electrical energy.

15. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 12 or 13.

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