Battery heating circuit, battery system, and electrical device

Abstract

The present application relates to the technical field of batteries, and provides a battery heating circuit, a battery system, and an electrical device. The battery comprises a first battery pack and a second battery pack connected in series. The battery heating circuit comprises a first switch circuit, a second switch circuit, a first energy storage circuit, and a controller. The first switch circuit and the second switch circuit are configured to: connect the first battery pack to the first energy storage circuit to form a first heating loop; connect the second battery pack to the first energy storage circuit to form a second heating loop; and connect the first battery pack and the second battery pack to the first energy storage circuit to form a third heating loop. The battery heating circuit of the present application can improve battery heating efficiency.

Description

Battery heating circuit, battery system and electrical device

[0001] Cross-references

[0002] This application incorporates Chinese Patent Application No. 202422923927.4, filed on November 28, 2024, entitled “Battery Heating Circuit, Battery System and Electrical Device”, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery heating circuit, a battery system, and an electrical device. Background Technology

[0004] 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.

[0005] To address the issue of low battery charging efficiency in low-temperature environments, the battery can be preheated, and then charged once the temperature reaches the required level. However, current battery charging methods are relatively limited and cannot meet the diverse heating needs of batteries, resulting in low heating efficiency. Summary of the Invention

[0006] This application aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of this application is to provide a battery heating circuit, a battery system, and an electrical device to solve the aforementioned problems existing in the related art.

[0007] An embodiment of the first aspect of this application provides a battery heating circuit. The battery includes a first battery pack and a second battery pack connected in series. The battery heating circuit includes: a first switching circuit, including a first connection point, a second connection point, and a third connection point interconnected by a first switching element, wherein the first connection point is connected to the positive terminal of the battery and the second connection point is connected to the negative terminal of the battery; a second switching circuit, including a fourth connection point, a fifth connection point, and a sixth connection point interconnected by a second switching element, wherein the fourth connection point is connected to either the positive or negative terminal of the battery and the fifth connection point is connected to the midpoint between the first battery pack and the second battery pack; and a first energy storage circuit, wherein a first end of the first energy storage circuit is connected to the third connection point and a second end is connected to the sixth connection point. The first switching circuit and the second switching circuit are configured to connect the first battery pack and the first energy storage circuit to form a first heating circuit, connect the second battery pack and the first energy storage circuit to form a second heating circuit, and connect the first battery pack and the second battery pack and the first energy storage circuit to form a third heating circuit.

[0008] In the technical solution of this application embodiment, in the first heating circuit, the first energy storage circuit, due to its energy storage function, can exchange energy with the first battery pack, thereby heating the first battery pack. Similarly, in the second heating circuit, the first energy storage circuit exchanges energy with the second battery pack, thereby heating the second battery pack. In the third heating circuit, the first energy storage circuit exchanges energy with both the first and second battery packs, thereby simultaneously heating both the first and second battery packs. By switching between at least two of the first, second, and third heating circuits, different heating circuits can be selected according to different heating requirements, thereby improving the heating effect and increasing heating efficiency.

[0009] In some embodiments, the first switching circuit includes at least one first bridge arm, with its two ends connected to a first connection point and a second connection point, respectively. The first bridge arm includes a first upper bridge arm and a first lower bridge arm connected in series, and the midpoint between the first upper bridge arm and the first lower bridge arm serves as a third connection point connected to the first energy storage circuit. Through the first upper bridge arm and the first lower bridge arm, the first connection point, the second connection point, and the third connection point can be interconnected, allowing the first energy storage circuit to selectively connect to either a first battery pack or a second battery pack. This enables the first energy storage circuit to connect to the first battery pack and the second battery pack respectively to form a first heating circuit and a second heating circuit, and also enables the first energy storage circuit to connect to the first battery pack and the second battery pack to form a third heating circuit, thereby heating the battery in different modes.

[0010] In some embodiments, the first energy storage circuit includes an inductor. The inductor can store a large amount of electricity, increasing the energy transferred in the first, second, or third heating circuit, thereby improving energy transfer efficiency and further enhancing the heating efficiency of the battery.

[0011] In some embodiments, there are multiple first bridge arms connected in parallel. The first energy storage circuit includes multiple first inductors connected in parallel, with each first inductor and each first bridge arm connected in a one-to-one correspondence. This parallel connection of multiple first inductors can suppress high-frequency noise flowing through the first inductors, resulting in a more stable circuit current and further improving the battery's heating efficiency.

[0012] In some embodiments, the plurality of first bridge arms and the plurality of first inductors are motors connected to the battery, wherein the plurality of first bridge arms are multi-phase bridge arms in the motor, and the plurality of first inductors are motor windings in the motor. In this way, if the battery is used in an electrical device and the electrical device has a motor, it is not necessary to additionally set up first inductors and first bridge arms, which can reduce the cost of the electrical device and does not excessively increase the complexity of the circuit wiring in the power supply device.

[0013] In some embodiments, the first energy storage circuit further includes a second inductor, which is connected in series with a plurality of first inductors that are connected in parallel. By connecting the second inductor in series, the energy that the first energy storage circuit can store can be increased, the energy transfer efficiency between the battery and the first energy storage circuit can be improved, and thus the heating efficiency of the battery can be improved.

[0014] In some embodiments, the second switching circuit includes a second bridge arm, with its two ends connected to a fourth connection point and a fifth connection point, respectively. The second bridge arm includes a second upper bridge arm and a second lower bridge arm connected in series, and the midpoint between the second upper bridge arm and the second lower bridge arm serves as a sixth connection point connected to the first energy storage circuit. Through the second upper bridge arm and the second lower bridge arm, the fourth connection point, the fifth connection point, and the sixth connection point can be interconnected, allowing the second terminal of the first energy storage circuit to selectively connect to the positive / negative terminal of the battery, or to the midpoint between the first battery pack and the second battery pack. This enables the first switching circuit and the second switching circuit to respectively form a first heating circuit, a second heating circuit, and a third heating circuit for heating the battery in different modes.

[0015] In some embodiments, when the first switching circuit includes a first bridge arm and the second switching circuit includes a second bridge arm, the second upper bridge arm connects to the midpoint between the first battery pack and the second battery pack, and the second lower bridge arm connects to the negative terminal of the battery. The first heating circuit includes: the first upper bridge arm, the first energy storage circuit, the second upper bridge arm, and the first battery pack; the second heating circuit includes: the first lower bridge arm, the first energy storage circuit, the second upper bridge arm, and the second battery pack; the third heating circuit includes: the first upper bridge arm, the first energy storage circuit, the second lower bridge arm, the first battery pack, and the second battery pack. By using different conduction methods for the first and second bridge arms, switching between the first, second, and third heating circuits can be achieved, making the battery heating method simple and easy to control. While simplifying the circuit, it can also improve the reliability of battery heating control.

[0016] In some embodiments, when the first switching circuit includes a first bridge arm and the second switching circuit includes a second bridge arm, the second upper bridge arm is connected to the positive terminal of the battery, and the second lower bridge arm is connected to the midpoint between the first battery pack and the second battery pack. The first heating circuit includes: the first upper bridge arm, the first energy storage circuit, the second lower bridge arm, and the first battery pack; the second heating circuit includes: the first lower bridge arm, the first energy storage circuit, the second lower bridge arm, and the second battery pack; the third heating circuit includes: the first lower bridge arm, the first energy storage circuit, the second upper bridge arm, the first battery pack, and the second battery pack. By using different conduction methods for the first and second bridge arms, switching between the first, second, and third heating circuits can be achieved, making the battery heating method simple and easy to control. While simplifying the circuit, it can also improve the reliability of battery heating control.

[0017] 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 the battery, and a second terminal of the second energy storage circuit is connected to the negative terminal of the battery. The second energy storage circuit connects the positive and negative terminals of the battery and can also form a circuit with the battery to achieve energy exchange, thereby further improving the battery's heating efficiency.

[0018] In some embodiments, the first energy storage circuit includes at least one inductor, and the second energy storage circuit includes a capacitor. Inductors can store a larger amount of electricity, improving energy transfer efficiency and thus enhancing battery heating efficiency. Compared to inductors, capacitors are smaller and can achieve rapid charging and discharging, improving battery heating efficiency while maintaining a small battery heating circuit size.

[0019] An embodiment of the second aspect of this application provides a battery system including a battery comprising a first battery pack and a second battery pack connected in series; and the battery heating circuit described in the above embodiment.

[0020] An embodiment of the third aspect of this application provides an electrical device that includes the battery system described in the above embodiments, the battery system being used to provide electrical energy.

[0021] 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, specific embodiments of this application are given below. Attached Figure Description

[0022] 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.

[0023] Figure 1 is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0024] Figure 2 is a functional block diagram of a battery heating circuit according to some embodiments of this application;

[0025] Figure 3 is a functional block diagram of a battery heating circuit according to some other embodiments of this application;

[0026] Figure 4 is one of the schematic diagrams of the current path for forming the first heating circuit in the battery heating circuit of some embodiments of this application;

[0027] Figure 5 is one of the schematic diagrams of the current path for forming a second heating circuit in the battery heating circuit of some embodiments of this application;

[0028] Figure 6 is a second schematic diagram of the current path for forming a second heating circuit in the battery heating circuit of some embodiments of this application;

[0029] Figure 7 is a second schematic diagram of the current path for forming the first heating circuit in the battery heating circuit of some embodiments of this application;

[0030] Figure 8 is one of the schematic diagrams of the current path for forming a third heating circuit in the battery heating circuit of some embodiments of this application;

[0031] Figure 9 is a second schematic diagram of the current path for forming a third heating circuit in the battery heating circuit of some embodiments of this application;

[0032] Figure 10 is one of the schematic diagrams of the current path for forming a third heating circuit in the battery heating circuit of some other embodiments of this application;

[0033] Figure 11 is one of the schematic diagrams of the current path for forming a second heating circuit in the battery heating circuit of some other embodiments of this application;

[0034] Figure 12 is a second schematic diagram of the current path for forming a second heating circuit in a battery heating circuit according to some other embodiments of this application;

[0035] Figure 13 is a second schematic diagram of the current path for forming a third heating circuit in a battery heating circuit according to some other embodiments of this application;

[0036] Figure 14 is a schematic diagram of the battery heating circuit of some embodiments of this application;

[0037] Figure 15 is a schematic diagram of the battery heating circuit of some other embodiments of this application;

[0038] Figure 16 is a schematic diagram of the battery heating circuit according to some embodiments of this application;

[0039] Figure 17 is a schematic diagram of the current path for performing the first step in the first heating stage of heating the battery according to some embodiments of this application;

[0040] Figure 18 is a schematic diagram of the current path for performing the second step in the first heating stage of heating the battery according to some embodiments of this application;

[0041] Figure 19 is a schematic diagram of the current path for performing the second step in the second heating stage of heating the battery according to some embodiments of this application;

[0042] Figure 20 is a schematic diagram of the current path for performing the first step in the second heating stage of heating the battery according to some embodiments of this application;

[0043] Figure 21 is a schematic diagram of the current path for performing the third step in the first heating stage of the battery according to some other embodiments of this application;

[0044] Figure 22 is a schematic diagram of the current path for performing the third step in the second heating stage of the battery according to some other embodiments of this application.

[0045] Explanation of reference numerals in the attached drawings: Vehicle 1000; Battery 100, First switching circuit 101, Second switching circuit 102, First energy storage circuit 103, Second energy storage circuit 105; Vehicle controller 200; Motor 300; First battery pack 11, Second battery pack 12; First bridge arm 20, Current sensor 21, First connector 22, Second connector 23; Second bridge arm 30; First freewheeling diode D1, Second freewheeling diode D2, Third freewheeling diode D3, Fourth freewheeling diode D4, First switch K1, Second switch K2, Third switch K3, Fourth switch K4, First connection point P1, Second connection point P2, Third connection point P3, Fourth connection point P4, Fifth connection point P5, Sixth connection point P6, First resistor R1, First upper bridge arm switch V1, First lower bridge arm switch V2, Second upper bridge arm switch V3, Second upper bridge arm switch V4. Detailed Implementation

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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).

[0052] To address the issue of low charging efficiency of batteries in low-temperature environments, batteries are typically heated until their temperature reaches the required level before charging.

[0053] In related technologies, external heating devices are typically used to heat the battery, such as PTC (Positive Temperature Coefficient) thermistors. This heating method relies on the principle of heat transfer to achieve heat exchange between the external heating device and the battery. However, this method has low heating efficiency and can easily lead to uneven temperatures between the outside and inside of the battery.

[0054] Furthermore, the relevant technologies cannot meet the different heating needs of batteries or provide different heating modes, resulting in poor heating effect and low heating efficiency of batteries.

[0055] Based on the above considerations, a battery heating circuit was designed, including a first switching circuit, a second switching circuit, a first energy storage circuit, and a controller. The first switching circuit includes a first connection point, a second connection point, and a third connection point interconnected by a first switching element. The first connection point is connected to the positive terminal of the battery, and the second connection point is connected to the negative terminal of the battery. The second switching circuit includes a fourth connection point, a fifth connection point, and a sixth connection point interconnected by a second switching element. The fourth connection point is connected to either the positive or negative terminal of the battery, and the fifth connection point is connected to the midpoint between the first and second battery packs.

[0056] The first end of the first energy storage circuit is connected to the third connection point, so that it can be connected to the positive or negative terminal of the battery through the first switching circuit. The second end of the first energy storage circuit is connected to the sixth connection point, so that it can be connected to the first battery pack or the second battery pack through the second switching circuit.

[0057] The first switching circuit and the second switching circuit are configured to connect the first battery pack and the first energy storage circuit to form a first heating circuit, so that energy exchange occurs between the first battery pack and the first energy storage circuit, thereby heating the first battery pack.

[0058] The first switching circuit is also configured to connect the second battery pack to the first energy storage circuit to form a second heating circuit, so that energy can be exchanged between the second battery pack and the first energy storage circuit, thereby heating the second battery pack.

[0059] The first switching circuit is also configured to connect the first battery pack, the second battery pack, and the first energy storage circuit to form a third heating circuit, so that the first battery pack and the second battery pack exchange energy with the first energy storage circuit, thereby simultaneously heating the first battery pack and the second battery pack.

[0060] By using energy transfer, the battery can be self-heated, achieving a uniform and rapid increase in battery temperature without the need for external heating equipment, thus reducing costs.

[0061] By controlling the switching between at least two of the first, second, and third heating circuits, different heating circuits can be selected according to different heating needs, thereby improving the heating effect and increasing heating efficiency.

[0062] The battery heating circuit disclosed in this application can be used, but is not limited to, for heating batteries in electrical devices such as vehicles, ships, or aircraft.

[0063] 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.

[0064] 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.

[0065] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in 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.

[0066] 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.

[0067] Referring to Figures 2 and 3, this application embodiment provides a battery including a first battery pack 11 and a second battery pack 12 connected in series. The battery heating circuit includes: a first switching circuit 101, including a first connection point P1, a second connection point P2, and a third connection point P3 interconnected by a first switching element, wherein the first connection point P1 is connected to the positive terminal of the battery, and the second connection point P2 is connected to the negative terminal of the battery; and a second switching circuit 102, including a fourth connection point P4, a fifth connection point P5, and a sixth connection point P6 interconnected by a second switching element, wherein the fourth connection point P4 is connected to either the positive or negative terminal of the battery. The fifth connection point P5 connects to the midpoint between the first battery pack 11 and the second battery pack 12; the first energy storage circuit 103 has its first end connected to the third connection point P3 and its second end connected to the sixth connection point P6; the first switching circuit 101 and the second switching circuit 102 are configured to connect the first battery pack 11 to the first energy storage circuit 103 to form a first heating circuit, connect the second battery pack 12 to the first energy storage circuit 103 to form a second heating circuit, and connect the first battery pack 11 and the second battery pack 12 to the first energy storage circuit 103 to form a third heating circuit.

[0068] When the positive terminal of the first battery pack 11 is connected to the negative terminal of the second battery pack 12, the positive terminal of the battery is the positive terminal of the second battery pack 12, and the negative terminal of the battery is the negative terminal of the first battery pack 11. When the negative terminal of the first battery pack 11 is connected to the positive terminal of the second battery pack 12, the positive terminal of the battery is the positive terminal of the first battery pack 11, and the negative terminal of the battery is the negative terminal of the second battery pack 12.

[0069] The first connection point P1 can be the node connecting the first switching circuit 101 and the positive terminal of the battery, the second connection point P2 can be the node connecting the first switching circuit 101 and the negative terminal of the battery, and the third connection point P3 can be the node connecting the first energy storage circuit 103 and the first switching circuit 101.

[0070] Any two of the first connection point P1, the second connection point P2, and the third connection point P3 can be connected by a first switching element. For example, when the first connection point P1 and the second connection point P2 are connected by the first switching element, a path is formed between the first connection point P1 and the second connection point P2.

[0071] It is understandable that the first connection point P1, the second connection point P2, and the third connection point P3 can all be connected.

[0072] The fourth connection point P4 can be the node connecting the second switch circuit 102 and the positive / negative terminal of the battery. The fifth connection point P5 can be the node connecting the second switch circuit 102 and the midpoint between the first battery pack 11 and the second battery pack 12. The sixth connection point P6 can be the node connecting the first energy storage circuit 103 and the second switch circuit 102.

[0073] Any two of the fourth connection point P4, the fifth connection point P5, and the sixth connection point P6 can be connected by the second switching element.

[0074] It is understandable that the fourth connection point P4, the fifth connection point P5, and the sixth connection point P6 can all be connected.

[0075] In some embodiments, the first switching element and the second switching element may include, but are not limited to, components capable of controlling the switching on and off of a circuit, such as a MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT transistor (Insulated-Gate Bipolar Transistor), or a relay.

[0076] In one heating mode, switching between the first and second heating circuits can be controlled, thus providing balanced heating to both the first battery pack 11 and the second battery pack 12, suitable when the temperatures of the first and second battery packs 11 and 12 are close to or equal. In another heating mode, switching between the first, second, and third heating circuits can also be controlled, suitable when the temperatures of the first and second battery packs 11 and 12 are both low and require rapid heating. In yet another heating mode, switching between the first and third heating circuits can be controlled, suitable when the temperature of the first battery pack 11 is lower than that of the second battery pack 12, resulting in the temperatures of the first and second battery packs 11 becoming close to or equal after heating. In yet another heating mode, switching between the second and third heating circuits can be controlled, suitable when the temperature of the second battery pack 12 is lower than that of the first battery pack 11, resulting in the temperatures of the first and second battery packs 11 becoming close to or equal after heating.

[0077] The following describes in detail the switching between at least two of the first heating circuit, the second heating circuit, and the third heating circuit, taking the example of connecting the negative terminal of the first battery pack 11 to the positive terminal of the second battery pack 12.

[0078] Referring to Figure 2, in some embodiments, the fourth connection point P4 can be connected to the positive terminal of the battery.

[0079] As shown in Figures 4 and 7, when the first connection point P1 and the third connection point P3 are connected, and the fifth connection point P5 and the sixth connection point P6 are connected, the first end of the first energy storage circuit 103 is connected to the positive terminal of the first battery pack 11 through the first connection point P1, and the second end of the first energy storage circuit 103 is connected to the negative terminal of the first battery pack 11 through the fifth connection point P5. The first battery pack 11 and the first energy storage circuit 103 constitute the first heating circuit.

[0080] As shown in Figures 5 and 6, when the second connection point P2 and the third connection point P3 are connected, and the fifth connection point P5 and the sixth connection point P6 are connected, the first end of the first energy storage circuit 103 is connected to the negative terminal of the second battery pack 12 through the second connection point P2, and the second end of the first energy storage circuit 103 is connected to the positive terminal of the second battery pack 12 through the fifth connection point P5. The second battery pack 12 and the first energy storage circuit 103 constitute the second heating circuit.

[0081] As shown in Figures 8 and 9, when the second connection point P2 and the third connection point P3 are connected, and the fourth connection point P4 and the sixth connection point P6 are connected, the first end of the first energy storage circuit 103 is connected to the negative terminal of the second battery pack 12 through the second connection point P2, and the second end of the first energy storage circuit 103 is connected to the positive terminal of the first battery pack 11 through the fourth connection point P4. The first battery pack 11, the second battery pack 12 and the first energy storage circuit 103 constitute the third heating circuit.

[0082] In one example, heating the battery may include alternating first heating stage and second heating stage. In the first heating stage, the first heating circuit and the second heating circuit may be controlled to alternate sequentially. In the second heating stage, the second heating circuit and the first heating circuit may be controlled to alternate sequentially.

[0083] In the first heating stage, the formation of the first heating circuit is controlled first. The first energy storage circuit 103 does not store energy, and the first battery pack 11 charges the first energy storage circuit 103, realizing the transfer of energy from the first battery pack 11 to the first energy storage circuit 103. During the energy transfer process, current flows through the first battery pack 11, achieving heating of the first battery pack 11. The solid line with arrows in Figure 4 shows the current path of the first battery pack 11 charging the first energy storage circuit 103 in the first heating circuit.

[0084] Next, the first heating circuit is switched to the second heating circuit. Since the first energy storage circuit 103 stored energy in the first heating circuit, it releases energy to the second battery pack 12 in the second heating circuit, thus transferring energy from the first energy storage circuit 103 to the second battery pack 12 to heat the second battery pack 12. The solid line with arrows in Figure 5 shows the current path of the first energy storage circuit 103 releasing energy to the second battery pack 12 in the second heating circuit.

[0085] In the second heating stage, the formation of the second heating circuit is first controlled. The first energy storage circuit 103 does not store energy, and the second battery pack 12 charges the first energy storage circuit 103, realizing the transfer of energy from the second battery pack 12 to the first energy storage circuit 103. During this energy transfer process, the second battery pack 12 is heated. The solid line with arrows in Figure 6 shows the current path of the second battery pack 12 charging the first energy storage circuit 103 in the second heating circuit.

[0086] Next, the second heating circuit is switched to the first heating circuit. Since the first energy storage circuit 103 stored energy in the previous second heating circuit, it releases energy to the first battery pack 11 in the first heating circuit, realizing the transfer of energy from the first energy storage circuit 103 to the first battery pack 11 to heat the first battery pack 11. The solid line with arrows in Figure 7 shows the current path of the first energy storage circuit 103 releasing energy to the first battery pack 11 in the first heating circuit.

[0087] In other words, during the first heating stage, energy transfer is realized from the first battery pack 11 to the second battery pack 12, and during the second heating stage, energy transfer is realized from the second battery pack 12 to the first battery pack 11. This ensures that the first battery pack 11 and the second battery pack 12 maintain energy balance after heating is completed, which is beneficial to maintaining the stability of the first battery pack 11 and the second battery pack 12.

[0088] In another example, heating the battery may include alternating first and second heating stages, in which a third heating circuit and a first heating circuit may be controlled to alternate sequentially, and in the second heating stage, the first heating circuit and the third heating circuit may be controlled to alternate sequentially.

[0089] In the first heating stage, the formation of the third heating circuit is controlled first, and the first battery pack 11 and the second battery pack 12 charge the first energy storage circuit 103 to achieve joint heating of the first battery pack 11 and the second battery pack 12. The solid lines with arrows in Figure 8 show the current path of the first battery pack 11 and the second battery pack 12 charging the first energy storage circuit 103 in the third heating circuit.

[0090] Next, the third heating circuit is switched to the first heating circuit. Since the first energy storage circuit 103 stored energy in the previous third heating circuit, the first energy storage circuit 103 releases energy to the first battery pack 11 in the first heating circuit to heat the first battery pack 11, as shown in Figure 7. The solid line with arrows in Figure 7 shows the current path of the first energy storage circuit 103 releasing energy to the first battery pack 11 in the first heating circuit of the first heating stage.

[0091] In the second heating stage, the formation of the first heating circuit is controlled first, and the first battery pack 11 charges the first energy storage circuit 103 to achieve heating of the first battery pack 11, as shown in Figure 4. The solid line with arrows in Figure 4 shows the current path of the first battery pack 11 charging the first energy storage circuit 103 in the first heating circuit.

[0092] Next, the first heating circuit is switched to the third heating circuit. Since the first energy storage circuit 103 stored energy in the first heating circuit, in the third heating circuit, the first energy storage circuit 103 releases energy to the first battery pack 11 and the second battery pack 12 to heat the first battery pack 11 and the second battery pack 12 together. The solid line with arrows in Figure 9 shows the current path of the first energy storage circuit 103 releasing energy to the first battery pack 11 and the second battery pack 12 in the third heating circuit of the second heating stage.

[0093] As can be seen from the above, during the formation of the third heating circuit, the first battery pack 11 and the second battery pack 12 can be heated together, thereby improving the heating efficiency of the battery.

[0094] Referring to Figure 3, in some other embodiments, the fourth connection point P4 may be connected to the negative terminal of the battery.

[0095] When the first connection point P1 and the third connection point P3 are connected, and the fifth connection point P5 and the sixth connection point P6 are connected, the first end of the first energy storage circuit 103 is connected to the positive terminal of the first battery pack 11 through the first connection point P1, and the second end of the first energy storage circuit 103 is connected to the negative terminal of the first battery pack 11 through the fifth connection point P5. The first battery pack 11 and the first energy storage circuit 103 constitute the first heating circuit.

[0096] When the second connection point P2 and the third connection point P3 are connected, and the fifth connection point P5 and the sixth connection point P6 are connected, the first end of the first energy storage circuit 103 is connected to the negative terminal of the second battery pack 12 through the second connection point P2, and the second end of the first energy storage circuit 103 is connected to the positive terminal of the second battery pack 12 through the fifth connection point P5. The second battery pack 12 and the first energy storage circuit 103 constitute the second heating circuit.

[0097] When the first connection point P1 and the third connection point P3 are connected, and the fourth connection point P4 and the sixth connection point P6 are connected, the first end of the first energy storage circuit 103 is connected to the positive terminal of the first battery pack 11 through the first connection point P1, and the second end of the first energy storage circuit 103 is connected to the negative terminal of the second battery pack 12 through the fourth connection point P4. The first battery pack 11, the second battery pack 12 and the first energy storage circuit 103 constitute the third heating circuit.

[0098] In one example, heating the battery may include alternating first and second heating stages. In the first heating stage, the first and second heating circuits may be controlled to alternate sequentially. In the second heating stage, the second and first heating circuits may be controlled to alternate sequentially. The method is described above and will not be repeated here.

[0099] In another example, heating the battery may include alternating first and second heating stages, in which a third heating circuit and a second heating circuit may be controlled to alternate sequentially, and in the second heating stage, the second heating circuit and the third heating circuit may be controlled to alternate sequentially.

[0100] In the first heating stage, the formation of the third heating circuit is controlled first. The first battery pack 11 and the second battery pack 12 jointly charge the first energy storage circuit 103, thereby heating the first battery pack 11 and the second battery pack 12. The solid lines with arrows in Figure 10 show the current path of the first battery pack 11 and the second battery pack 12 charging the first energy storage circuit 103 in the third heating circuit.

[0101] Next, the third heating circuit is switched to the second heating circuit. Since the first energy storage circuit 103 stored energy in the previous third heating circuit, it charges the second battery pack 12 in the second heating circuit to heat the second battery pack 12. The solid line with arrows in Figure 11 shows the current path of the first energy storage circuit 103 charging the second battery pack 12 in the second heating circuit.

[0102] In the second heating stage, the second heating circuit is first formed, and the second battery pack 12 charges the first energy storage circuit 103 to heat the second battery pack 12. The solid line with arrows in Figure 12 shows the current path of the second battery pack 12 charging the first energy storage circuit 103 in the second heating circuit.

[0103] Next, the second heating circuit is switched to the third heating circuit. Since the first energy storage circuit 103 stored energy in the previous second heating circuit, in the third heating circuit, the first energy storage circuit 103 charges the first battery pack 11 and the second battery pack 12 to heat them. The solid lines with arrows in Figure 13 show the current path of the first energy storage circuit 103 charging the first battery pack 11 and the second battery pack 12 in the third heating circuit.

[0104] As can be seen from the above, during the formation of the third heating circuit, the first battery pack 11 and the second battery pack 12 can be heated together, thereby improving the heating efficiency of the battery.

[0105] In other embodiments, the heating of the battery may also include only one heating stage, in which the first heating circuit and the third heating circuit may be controlled to alternate, or the second heating circuit and the third heating circuit may alternate. The control method is similar to the method described above, and will not be repeated below.

[0106] In some embodiments, the first energy storage circuit 103 may include, but is not limited to, energy storage elements such as inductors and capacitors that are capable of storing and releasing energy.

[0107] In some embodiments, the battery heating circuit may further include a controller configured to control the first switching circuit 101 and the second switching circuit 102 to switch between at least two of the first heating circuit, the second heating circuit, and the third heating circuit.

[0108] The controller can achieve different conduction modes between the first connection point P1, the second connection point P2, and the third connection point P3 by controlling the on / off mode of the first switching element, and achieve different conduction modes between the fourth connection point P4, the fifth connection point P5, and the sixth connection point P6 by controlling the on / off mode of the second switching element, thereby realizing the switching of at least two of the first heating circuit, the second heating circuit, and the third heating circuit.

[0109] In some embodiments, the controller may include, but is not limited to, the vehicle's MCU (Microcontroller Unit) or the controller in the battery's BMS (Battery Management System).

[0110] In some embodiments, the battery further includes a temperature sensor for detecting the temperature of the first battery pack 11 and the second battery pack 12. The temperature sensor is communicatively connected to the BMS (Battery Management System). The controller in the BMS can receive the temperature information of the first battery pack 11 and the second battery pack 12 detected by the temperature sensor, and in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value, control the first switching circuit 101 and the second switching circuit 102 to switch between at least two of the first heating circuit, the second heating circuit, and the third heating circuit.

[0111] In the above technical solution, in the first heating circuit, the first energy storage circuit 103, due to its energy storage function, can exchange energy with the first battery pack 11, thereby heating the first battery pack 11. Similarly, in the second heating circuit, the first energy storage circuit 103 exchanges energy with the second battery pack 12, thereby heating the second battery pack 12. In the third heating circuit, the first energy storage circuit 103 exchanges energy with the first battery pack 11 and the second battery pack 12, thereby simultaneously heating both the first battery pack 11 and the second battery pack 12. By controlling the switching between at least two of the first, second, and third heating circuits, different heating circuits can be selected according to different heating requirements to improve the heating effect and increase heating efficiency.

[0112] Referring to Figures 14 and 15, according to some embodiments of this application, the first switching circuit includes at least one first bridge arm 20, the two ends of the first bridge arm 20 being connected to a first connection point P1 and a second connection point P2 respectively, the first bridge arm 20 including a first upper bridge arm and a first lower bridge arm connected in series, and the midpoint between the first upper bridge arm and the first lower bridge arm being connected to the first energy storage circuit 103 as a third connection point P3.

[0113] The first upper bridge arm is connected to the first connection point P1, and the first lower bridge arm is connected to the second connection point P2. The first upper bridge arm may include a first upper bridge arm switch V1, and the first lower bridge arm may include a first lower bridge arm switch V2. The first upper bridge arm switch V1 can serve as a first switching element, and the first lower bridge arm switch V2 can serve as a second switching element. By turning the first upper bridge arm switch V1 and the first lower bridge arm switch V2 on / off, the first upper bridge arm and the first lower bridge arm can be turned on or off. The types of the first upper bridge arm switch V1 and the first lower bridge arm switch V2 include, but are not limited to, MOSFETs or IGBTs.

[0114] The controller can control the different conduction timings of the first upper bridge arm and the first lower bridge arm in the first bridge arm 20 to achieve the connection between the first connection point P1 and the third connection point P3, or to achieve the connection between the second connection point P2 and the third connection point P3, thereby enabling the switching between the first heating circuit, the second heating circuit and the third heating circuit.

[0115] In some embodiments, the first upper bridge arm switch V1 is provided with a first freewheeling diode D1, and the first lower bridge arm switch V2 is provided with a second freewheeling diode D2. In this way, at the instant the first upper bridge arm switch V1 is turned off, the current can flow through the first freewheeling diode D1, and at the instant the first lower bridge arm switch V2 is turned off, the current can flow through the second freewheeling diode D2. At the instant the controller controls the switching of at least two of the first heating circuit, the second heating circuit, and the third heating circuit, the stability of the current flow can be maintained.

[0116] In some embodiments, the battery heating circuit further includes a first switch K1 and a second switch K2. The first end of the first switch K1 is connected to the positive terminal of the battery, and the second end of the first switch K1 is connected to the first upper bridge arm, used to control the connection or disconnection between the positive terminal of the battery and the first upper bridge arm. The first end of the second switch K2 is connected to the negative terminal of the battery, and the second end of the second switch K2 is connected to the first lower bridge arm, used to control the connection / disconnection between the negative terminal of the battery and the first lower bridge arm. Thus, when the battery needs to be heated, the first switch K1 and the second switch K2 can control the connection between the battery and the first bridge arm; when the battery does not need to be heated, the first switch K1 and the second switch K2 can control the disconnection between the battery and the first bridge arm, thereby not affecting the normal performance of the battery.

[0117] In some embodiments, the first switch K1 can be connected to the first upper bridge arm via the first connector 22, and the second switch K2 can be connected to the first lower bridge arm via the second connector 23.

[0118] In some embodiments, the battery heating circuit further includes a third switch K3 connected in parallel with the second switch K2 and a first resistor R1. The third switch and the first resistor are connected in series to provide current limiting protection.

[0119] In some embodiments, the battery heating circuit further includes a current sensor 21, which is connected between the positive terminal of the battery and the first switch to detect the current output by the battery, so as to regulate the current used for battery heating in the battery heating circuit to produce a better heating effect on the battery.

[0120] In some embodiments, the first switch K1, the second switch K2, and the third switch K3 may include, but are not limited to, relays.

[0121] In the above technical solution, the first bridge arm 20 has a simple structure and is easy to control, which simplifies the circuit and improves the reliability of battery heating control. Furthermore, through the first upper bridge arm and the first lower bridge arm, the first connection point P1, the second connection point P2, and the third connection point P3 can be interconnected, allowing the first energy storage circuit 103 to selectively connect to the first battery pack 11 or the second battery pack 12. This enables the first energy storage circuit 103 to be connected to the first battery pack 11 and the second battery pack 12 respectively to form a first heating circuit and a second heating circuit, and also enables the first energy storage circuit 103 to be connected to the first battery pack 11 and the second battery pack 12 to form a third heating circuit, thereby heating the battery in different modes.

[0122] According to some embodiments of this application, the first energy storage circuit 103 includes an inductor.

[0123] In some embodiments, if there is one first bridge arm in the first switching circuit, then there can be one inductor in the first energy storage element. The first end of the inductor is connected to the midpoint of the first bridge arm, and the second end is connected to the sixth connection point of the second switching circuit.

[0124] In other embodiments, the first switching circuit has multiple first bridge arms connected in parallel. Similarly, the first energy storage element can have multiple inductors connected in parallel, with each inductor corresponding to one of the first bridge arms. When multiple inductors are connected in parallel, high-frequency noise in the current flowing through the inductors can be suppressed, making the current in the circuit more stable and further increasing the battery's heating efficiency.

[0125] In the above technical solution, the inductor can store a large amount of electricity, which can increase the energy transferred in the first heating circuit / second heating circuit / third heating circuit, thereby improving the energy transfer efficiency and further improving the heating efficiency of the battery.

[0126] Referring again to Figures 14 and 15, according to some embodiments of this application, there are multiple first bridge arms 20 connected in parallel, and the first energy storage circuit 103 includes multiple first inductors L1 connected in parallel, with each of the multiple first inductors L1 and the multiple first bridge arms 20 connected in a one-to-one correspondence.

[0127] The first end of the first inductor L1 can be connected to the midpoint between the first upper bridge arm and the first lower bridge arm, and the second end of the first inductor L1 can be connected to the sixth connection point P6.

[0128] In some embodiments, the number of first bridge arms 20 and first inductors L1 can be two, three or more, and different numbers of first bridge arms 20 and first inductors L1 can be set according to different heating requirements.

[0129] In the above technical solution, multiple first inductors L1 and multiple first bridge arms 20 are connected one-to-one, forming multiple first heating circuits / second heating circuits / third heating circuits, thereby improving heating efficiency. Furthermore, the parallel connection of multiple first inductors L1 can suppress high-frequency noise flowing through the first inductors L1, making the circuit current more stable and further improving the battery's heating efficiency.

[0130] According to some embodiments of this application, a plurality of first bridge arms 20 and a plurality of first inductors L1 are motors connected to a battery, wherein the plurality of first bridge arms 20 are multi-phase bridge arms in the motor, and the plurality of first inductors L1 are motor windings in the motor.

[0131] In some embodiments, the plurality of first bridge arms 20 may be three-phase bridge arms in a motor.

[0132] In some embodiments, the plurality of first inductors L1 can be three-phase motor windings in a motor.

[0133] In some embodiments, when the battery is used in an electrical device, the motor can be a motor in the electrical device. For example, in the case of a battery in a vehicle, the vehicle has a motor, and the three parallel first inductors L1 can reuse the motor in the vehicle, and the three parallel first bridge arms 20 can reuse the three-phase bridge arms of the motor in the vehicle. In this way, both the first switching circuit 101 and the first energy storage circuit 103 can reuse the existing motor, reducing costs.

[0134] In the above technical solution, if the battery is used in an electrical device and the electrical device has a motor, there is no need to set up an inductor to form the first energy storage circuit 103, which can reduce the cost of the electrical device and will not increase the complexity of the circuit wiring in the power supply device.

[0135] Referring to FIG16, according to some embodiments of the present application, the first energy storage circuit 103 further includes: a second inductor L2, which is connected in series with a plurality of first inductors L1 connected in parallel.

[0136] As an example, Figure 16 shows the structure in which the first energy storage circuit 103 further includes a second inductor L2 when the fourth connection point P4 is connected to the negative terminal of the battery. The structure in which the first energy storage circuit 103 further includes a second inductor when the fourth connection point P4 is connected to the positive terminal of the battery can be referenced to the structure of the first energy storage circuit 103 shown in Figure 16.

[0137] The first end of the second inductor L2 is connected to the second end of the multiple first inductors L1 connected in parallel, and the second end of the second inductor L2 is connected to the sixth connection point P6.

[0138] In the above technical solution, by connecting the second inductor L2 in series, the energy that the first energy storage circuit 103 can store can be increased, the energy transfer efficiency between the battery and the first energy storage circuit 103 can be improved, and the heating efficiency of the battery can be improved.

[0139] Referring to Figures 14 and 15, according to some embodiments of this application, the second switching circuit 102 includes a second bridge arm 30, the two ends of which are connected to a fourth connection point P4 and a fifth connection point P5, respectively. The second bridge arm 30 includes a second upper bridge arm and a second lower bridge arm connected in series. The midpoint between the second upper bridge arm and the second lower bridge arm is connected to the first energy storage circuit 103 as a sixth connection point P6.

[0140] The second upper bridge arm may include a second upper bridge arm switch V3, and the second lower bridge arm may include a second lower bridge arm switch V4. By turning the second upper bridge arm switch V3 and the second lower bridge arm switch V4 on or off, the second upper bridge arm and the second lower bridge arm can be switched on or off. The types of the second upper bridge arm switch V3 and the second lower bridge arm switch V4 include, but are not limited to, MOSFETs or IGBTs. The second upper bridge arm switch V3 can be used as a third switching element, and the second lower bridge arm switch V4 can be used as a fourth switching element.

[0141] As shown in Figure 14, in some embodiments, the second upper bridge arm can be connected to the positive terminal of the battery, and the second lower bridge arm can be connected to the midpoint between the first battery pack 11 and the second battery pack 12. That is, the second upper bridge arm is connected to the fourth connection point P4, the fourth connection point P4 is connected to the positive terminal of the battery, and the second lower bridge arm is connected to the fifth connection point P5.

[0142] As shown in Figure 15, in some other embodiments, the second upper bridge arm may also be connected to the midpoint between the first battery pack 11 and the second battery pack 12, and the second lower bridge arm may also be connected to the negative terminal of the battery. That is, the second upper bridge arm is connected to the fifth connection point P5, the second lower bridge arm is connected to the fourth connection point P4, and the fourth connection point P4 is connected to the negative terminal of the battery.

[0143] In some embodiments, the second upper bridge arm switch V3 is provided with a corresponding third freewheeling diode D3, and the second lower bridge arm switch V4 is provided with a corresponding fourth freewheeling diode D4. At the instant of switching between any two of the first heating circuit, the second heating circuit, and the third heating circuit, the current can freewheel in the corresponding third freewheeling diode D3 or fourth freewheeling diode D4, maintaining the stability of the current flow.

[0144] In the above technical solution, the second bridge arm has a simple structure and is easy to control, which simplifies the circuit and improves the reliability of battery heating control. Furthermore, the second upper bridge arm and the second lower bridge arm enable interconnection between the fourth connection point P4, the fifth connection point P5, and the sixth connection point P6, allowing the second terminal of the first energy storage circuit 103 to selectively connect to the positive or negative terminal of the battery, or to the midpoint of the first battery pack 11 and the second battery pack 12. This allows the first switching circuit 101 and the second switching circuit 102 to form a first heating circuit, a second heating circuit, and a third heating circuit, respectively, to heat the battery in different modes.

[0145] Referring to Figures 17 to 22, according to some embodiments of this application, when the first switching circuit includes a first bridge arm 20 and the second switching circuit includes a second bridge arm 30, the second upper bridge arm is connected to the midpoint between the first battery pack 11 and the second battery pack 12, and the second lower bridge arm is connected to the negative terminal of the battery. The first heating circuit includes: the first upper bridge arm, the first energy storage circuit 103, the second upper bridge arm, and the first battery pack 11; the second heating circuit includes: the first lower bridge arm, the first energy storage circuit 103, the second upper bridge arm, and the second battery pack 12; the third heating circuit includes: the first upper bridge arm, the first energy storage circuit 103, the second lower bridge arm, the first battery pack 11, and the second battery pack 12.

[0146] In some embodiments, the battery can be controlled to alternate between a first heating phase and a second heating phase.

[0147] In one example, during the first heating phase, the controller is configured to alternately execute a first step and a second step to alternately form a first heating circuit and a second heating circuit, and during the second heating phase, to alternately execute a second step and a first step to alternately form a second heating circuit and a first heating circuit.

[0148] The first step includes: controlling the first and second upper bridge arms to be on, and controlling the first and second lower bridge arms to be off. The second step includes: controlling the first lower bridge arm and the second upper bridge arm to be on, and controlling the first upper bridge arm and the second lower bridge arm to be off.

[0149] As shown in Figure 17, in the first heating stage, the first step is executed first to form a first heating circuit. Current flows out from the positive terminal of the first battery pack 11 and sequentially through the first upper bridge arm, the first energy storage circuit 103, and the second upper bridge arm before flowing back to the negative terminal of the first battery pack 11. The first energy storage circuit 103 stores energy. The solid lines with arrows in Figure 17 show the current path in the first heating circuit formed by executing the first step in the first heating stage.

[0150] As shown in Figure 18, the second step is then executed to form a second heating circuit. Current flows out of the first energy storage circuit 103 and sequentially through the second upper bridge arm, the positive terminal of the second battery pack 12, the negative terminal of the second battery pack 12, and the first lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the second battery pack 12. The solid lines with arrows in Figure 18 show the current path in the second heating circuit formed during the second step in the first heating stage.

[0151] As shown in Figure 19, in the second heating stage, the second step is first executed to form a second heating circuit. Current flows out from the positive terminal of the second battery pack 12 and sequentially through the second upper bridge arm, the first energy storage circuit 103, and the first lower bridge arm before flowing back to the negative terminal of the second battery pack 12. The first energy storage circuit 103 stores energy. The solid lines with arrows in Figure 19 show the current path in the second heating circuit formed by executing the second step in the second heating stage.

[0152] As shown in Figure 20, the first step is then executed to form a first heating circuit. Current flows out of the first energy storage circuit 103 and sequentially through the first upper bridge arm, the positive terminal of the first battery pack 11, the negative terminal of the first battery pack 11, and the second upper bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the first battery pack 11. The solid lines with arrows in Figure 20 show the current path in the first heating circuit formed by executing the first step during the second heating stage.

[0153] In another example, during the first heating phase, the controller is configured to alternately execute the third step and the second step in sequence to alternately form the third heating circuit and the second heating circuit, and during the second heating phase, to alternately execute the second step and the third step in sequence to alternately form the second heating circuit and the third heating circuit.

[0154] The third step includes: controlling the first upper bridge arm and the second lower bridge arm to be turned on, and controlling the first lower bridge arm and the second upper bridge arm to be turned off.

[0155] As shown in Figure 21, in the first heating stage, the third step is executed first to form a third heating circuit. Current flows out from the positive terminal of the first battery pack 11 and sequentially through the first upper bridge arm, the first energy storage circuit 103, the second lower bridge arm, the negative terminal of the second battery pack 12, and the positive terminal of the second battery pack 12 before flowing back to the negative terminal of the first battery pack 11. The solid lines with arrows in Figure 21 show the current path in the third heating circuit formed by executing the third step in the first heating stage.

[0156] As shown in Figure 18, the second step is then executed to form a second heating circuit. Current flows out of the first energy storage circuit 103 and sequentially through the second upper bridge arm, the positive terminal of the second battery pack 12, the negative terminal of the second battery pack 12, and the first lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the second battery pack 12. The solid lines with arrows in Figure 18 show the current path in the second heating circuit formed during the second step in the first heating stage.

[0157] As shown in Figure 19, in the second heating stage, the second step is first executed to form a second heating circuit, the second battery pack 12 charges the first energy storage circuit 103, and the first energy storage circuit 103 stores energy.

[0158] As shown in Figure 22, the third step is then executed to form a third heating circuit. Current flows out of the first energy storage circuit 103 and sequentially through the first upper bridge arm, the positive terminal of the first battery pack 11, the negative terminal of the first battery pack 11, the positive terminal of the second battery pack 12, the negative terminal of the second battery pack 12, and the second lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the first battery pack 11 and the second battery pack 12. The solid lines with arrows in Figure 22 show the current path in the third heating circuit formed during the second heating stage.

[0159] In the above technical solution, by using different conduction methods for the first and second bridge arms, the switching between the first heating circuit, the second heating circuit, and the third heating circuit can be achieved, making the battery heating method simple and easy to control. While simplifying the circuit, it can improve the reliability of battery heating control.

[0160] Referring to Figure 14, according to some embodiments of this application, when the first switching circuit includes a first bridge arm 20 and the second switching circuit includes a second bridge arm 30, the second upper bridge arm is connected to the positive terminal of the battery, and the second lower bridge arm is connected to the midpoint between the first battery pack 11 and the second battery pack 12. The first heating circuit includes: the first upper bridge arm, the first energy storage circuit 103, the second lower bridge arm, and the first battery pack 11; the second heating circuit includes: the first lower bridge arm, the first energy storage circuit 103, the second lower bridge arm, and the second battery pack 12; the third heating circuit includes: the first lower bridge arm, the first energy storage circuit 103, the second upper bridge arm, the first battery pack 11, and the second battery pack 12.

[0161] In some embodiments, the battery can be controlled to alternate between a first heating phase and a second heating phase.

[0162] In one example, the first heating circuit and the second heating circuit can be controlled to alternate sequentially. During the second heating stage, the second heating circuit and the first heating circuit can be controlled to alternate sequentially.

[0163] In the first heating stage, the controller first controls the first upper bridge arm and the second lower bridge arm to be turned on, and the first lower bridge arm and the second upper bridge arm to be turned off, forming a first heating circuit. Current flows out from the positive terminal of the first battery pack 11 and flows through the first upper bridge arm, the first energy storage circuit 103 and the second lower bridge arm in sequence, and then flows back to the negative terminal of the first battery pack 11. The first energy storage circuit 103 stores energy.

[0164] The controller then controls the first lower bridge arm and the second lower bridge arm to be turned on, and the first upper bridge arm and the second upper bridge arm to be turned off, forming a second heating circuit. Current flows out from the first energy storage circuit 103 and flows sequentially through the second lower bridge arm, the positive terminal of the second battery pack 12, the negative terminal of the second battery pack 12, and the first lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the second battery pack.

[0165] In the second heating stage, the controller first controls the first lower bridge arm and the second lower bridge arm to be turned on, and the first upper bridge arm and the second upper bridge arm to be turned off, forming a second heating circuit. The current flows out from the positive terminal of the second battery pack 12 and flows through the first lower bridge arm, the first energy storage circuit 103 and the second lower bridge arm in sequence, and then flows back to the negative terminal of the second battery pack 12. The first energy storage circuit 103 stores energy.

[0166] The controller then controls the first upper bridge arm and the second lower bridge arm to be turned on and the first lower bridge arm and the second upper bridge arm to be turned off, forming a first heating circuit. Current flows out from the first energy storage circuit 103 and flows sequentially through the first upper bridge arm, the positive terminal of the first battery pack 11, the negative terminal of the first battery pack 11, and the second lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the first battery pack.

[0167] In another example, heating the battery may include alternating first and second heating stages, in which a third heating circuit and a first heating circuit may be controlled to alternate sequentially, and in the second heating stage, the first heating circuit and the third heating circuit may be controlled to alternate sequentially.

[0168] In the first heating stage, the controller first controls the first lower bridge arm and the second upper bridge arm to be turned on, and the first upper bridge arm and the second lower bridge arm to be turned off, forming a third heating circuit. The current flows out from the positive terminal of the first battery pack 11 and flows sequentially through the second upper bridge arm, the first energy storage circuit 103, the first lower bridge arm, the negative terminal of the second battery pack 12, and the positive terminal of the second battery pack 12 before flowing back to the negative terminal of the first battery pack 11. The first energy storage circuit 103 stores energy.

[0169] The controller then controls the first upper bridge arm and the second lower bridge arm to be turned on and the first lower bridge arm and the second upper bridge arm to be turned off, forming a first heating circuit. Current flows out from the first energy storage circuit 103 and flows sequentially through the first upper bridge arm, the positive terminal of the first battery pack 11, the negative terminal of the first battery pack 11, and the second lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the first battery pack.

[0170] In the second heating stage, the controller first controls the first upper bridge arm and the second lower bridge arm to be turned on, and the first lower bridge arm and the second upper bridge arm to be turned off, forming the first heating circuit. The current flows out from the positive terminal of the first battery pack 11 and flows through the first upper bridge arm, the first energy storage circuit 103 and the second lower bridge arm in sequence, and then flows back to the negative terminal of the first battery pack 11. The first energy storage circuit 103 stores energy.

[0171] The controller then controls the first lower bridge arm and the second upper bridge arm to be turned on and the first upper bridge arm and the second lower bridge arm to be turned off, forming a third heating circuit. Current flows out from the first energy storage circuit 103 and flows sequentially through the second upper bridge arm, the positive terminal of the first battery pack 11, the negative terminal of the first battery pack 11, the positive terminal of the second battery pack 12, the negative terminal of the second battery pack 12, and the first lower bridge arm before flowing back to the first energy storage circuit 103. The first energy storage circuit 103 charges the first battery pack 11 and the second battery pack 12.

[0172] In the above technical solution, by using different conduction methods for the first and second bridge arms, the switching between the first heating circuit, the second heating circuit, and the third heating circuit can be achieved, making the battery heating method simple and easy to control. While simplifying the circuit, it can improve the reliability of battery heating control.

[0173] Referring to Figures 14 to 16, according to some embodiments of this application, the battery heating circuit further includes: a second energy storage circuit 105, the first end of the second energy storage circuit 105 being connected to the positive terminal of the battery, and the second end of the second energy storage circuit 105 being connected to the negative terminal of the battery.

[0174] That is, the second energy storage circuit 105 is connected in parallel across the two ends of the battery, enabling the first battery pack 11 or the second battery pack 12 to charge the second energy storage circuit 105 through the first switching circuit 101 and the first energy storage circuit 103, and the second energy storage circuit 105 to charge the first battery pack 11 or the second battery pack 12 through the first switching circuit 101 and the first energy storage circuit 103. In other words, the second energy storage circuit 105 can also exchange energy with the first battery pack 11 and the second battery pack 12 respectively, thereby heating the battery.

[0175] For example, the controller may control the batteries to alternate between a first heating phase and a second heating phase in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value.

[0176] During the first heating stage, the first battery pack 11 forms a first heating circuit through the first switching circuit 101 and the first energy storage circuit 103, and the first battery pack 11 charges the first energy storage circuit 103. During the formation of the first heating circuit, the second energy storage circuit 105 can form a circuit with the second battery pack 12 so that the second energy storage circuit 105 charges the second battery pack 12, and current flows through the second battery pack 12.

[0177] During the first heating stage, the second battery pack 12 forms a second heating circuit through the first switching circuit 101 and the first energy storage circuit 103, and the first energy storage circuit 103 discharges to the second battery pack 12. During the formation of the second heating circuit, the second energy storage circuit 105 can form a circuit with the first battery pack 11 so that the first battery pack 11 charges the second energy storage circuit 105, and current flows through the first battery pack 11.

[0178] During the second heating stage, the second battery pack 12 forms a second heating circuit through the first switching circuit 101 and the first energy storage circuit 103, and the second battery pack 12 charges the first energy storage circuit 103. During the formation of the second heating circuit, the second energy storage circuit 105 can form a circuit with the first battery pack 11 so that the second energy storage circuit 105 charges the first battery pack 11, and current flows through the first battery pack 11.

[0179] During the second heating stage, the first battery pack 11 forms a first heating circuit through the first switching circuit 101 and the first energy storage circuit 103, and the first energy storage circuit 103 discharges to the first battery pack 11. During the formation of the first heating circuit, the second energy storage circuit 105 can form a circuit with the second battery pack 12 so that the second battery pack 12 charges the second energy storage circuit 105, and current flows through the second battery pack 12.

[0180] In other words, during the entire heating phase, current always flows through the first battery pack 11 and the second battery pack 12, which helps to maintain the stability of the current flowing through the first battery pack 11 and the second battery pack 12. This improves the heating efficiency of the batteries and makes the performance of the first battery pack 11 and the second battery pack 12 more stable.

[0181] In the above technical solution, the second energy storage circuit 105 is connected to the positive and negative terminals of the battery and can also form a circuit with the battery to realize energy exchange with the battery, thereby further improving the heating efficiency of the battery.

[0182] According to some embodiments of this application, the first energy storage circuit 103 includes at least one inductor, and the second energy storage circuit 105 includes a capacitor.

[0183] Both inductors and capacitors have charging and discharging functions. The first energy storage circuit 103 includes an inductor, and the second energy storage circuit 105 includes a capacitor. This enables the first battery pack 11 to charge the first energy storage circuit 103 and the second energy storage circuit 105 to charge the second battery pack 12 simultaneously through the first switching circuit 101, and the first energy storage circuit 103 to charge the second battery pack 12 and the first battery pack 11 to charge the second energy storage circuit 105 simultaneously through the first switching circuit 101.

[0184] The capacitor is connected in parallel across the two ends of the battery. In the first battery pack 11, a circuit is formed through the first switching circuit 101 and the inductor. During the charging of the inductor, the capacitor can act as a substitute for the power source. Since the first switching circuit 101 and the inductor are connected, the capacitor can form a circuit with the second battery pack 12 through the first switching circuit 101 and the inductor. The current in this circuit charges the second battery pack 12 because the current flows in the first switching circuit 101 and the inductor.

[0185] When the second battery pack 12 forms a circuit through the first switching circuit 101 and the inductor, the capacitor can form a circuit with the first battery pack 11 through the first switching circuit 101 and the inductor during the charging of the second battery pack 12 by the inductor. The current in the circuit is in the direction of the current in the first switching circuit 101 and the inductor, so that the first battery pack 11 charges the capacitor.

[0186] Similarly, when the battery is in the second heating stage, the first switch circuit 101 can simultaneously charge the second battery pack 12 to the first energy storage circuit 103 and the second energy storage circuit 105 to the first battery pack 11, and the first switch circuit 101 can simultaneously charge the first energy storage circuit 103 to the first battery pack 11 and the second battery pack 12 to the second energy storage circuit 105.

[0187] During the charging of the inductor, the capacitor can form a circuit with the first battery pack 11 through the first switch circuit 101 and the inductor. The current in the circuit charges the first battery pack 11 because it flows along the direction of the current in the first switch circuit 101 and the inductor.

[0188] The first battery pack 11 forms a circuit through the first switching circuit 101 and the inductor, so that during the charging of the first battery pack 11 by the inductor, the capacitor can form a circuit with the second battery pack 12 through the first switching circuit 101 and the inductor, and the current in the circuit charges the capacitor by the second battery pack 12 because it flows along the direction of the first switching circuit 101 and the inductor.

[0189] In the above technical solutions, inductors can store a larger amount of electricity, which can improve energy transfer efficiency and thus improve the heating efficiency of the battery. Compared with inductors, capacitors are smaller in size and can achieve rapid charging and discharging, thus improving the heating efficiency of the battery while keeping the battery heating circuit small in size.

[0190] This application provides a battery system including a battery, which includes a first battery pack and a second battery pack connected in series; and the battery heating circuit described in the above embodiment.

[0191] The battery system has the beneficial effects of the battery heating circuit provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery heating circuit in the above embodiments, which will not be repeated here.

[0192] This application provides an electrical device that includes the battery system described in the above embodiments, the battery system being used to provide electrical energy.

[0193] The electrical devices can be referred to the relevant descriptions in the above embodiments, and will not be repeated below.

[0194] This application provides a battery heating circuit. The battery includes a first battery pack 11 and a second battery pack 12 connected in series. Referring to Figures 14 to 16, the battery heating circuit includes: a first switching circuit, including a first connection point P1, a second connection point P2, and a third connection point P3 interconnected by a first switching element. The first connection point P1 is connected to the positive terminal of the battery, and the second connection point P2 is connected to the negative terminal of the battery; a second switching circuit, including a fourth connection point P4, a fifth connection point P5, and a sixth connection point P6 interconnected by a second switching element. The fourth connection point P4 is connected to either the positive or negative terminal of the battery, and the fifth connection point P5 is connected to the midpoint between the first battery pack 11 and the second battery pack 12; and a first energy storage circuit, with a first end connected to the third connection point P3 and a second end connected to the sixth connection point P6. The first and second switching circuits are configured to connect the first battery pack 11 to the first energy storage circuit to form a first heating circuit, connect the second battery pack 12 to the first energy storage circuit to form a second heating circuit, and connect the first battery pack 11 and the second battery pack 12 to the first energy storage circuit to form a third heating circuit.

[0195] The first switching circuit includes three parallel first bridge arms 20. The two ends of each first bridge arm 20 are connected to a first connection point P1 and a second connection point P2, respectively, and the midpoint of the first bridge arm 20 serves as a third connection point P3. The three first bridge arms 20 can be multiplexed from the three-phase bridge arms in a motor. The second switching circuit includes a second bridge arm 30, and the midpoint of the second bridge arm 30 serves as a sixth connection point P6. In one example, as shown in Figure 14, the second upper bridge arm of the second bridge arm is connected to the positive terminal of the battery, and the second lower bridge arm is connected to the midpoint of the first battery pack 11 and the second battery pack 12. In another example, as shown in Figure 15, the second upper bridge arm of the second bridge arm is connected to the midpoint of the first battery pack 11 and the second battery pack 12, and the second lower bridge arm is connected to the negative terminal of the battery.

[0196] The first energy storage circuit may include three first inductors L1 connected in parallel, and the three first inductors L1 are connected one-to-one with the third connection point P3 of the first bridge arm 20. The three inductors may be multiplexed from the three-phase inductors in the motor.

[0197] Referring to Figure 16, the first energy storage may also include a second inductor L2, which is connected in series with the three inductors that are connected in parallel.

[0198] The method of connecting the first energy storage circuit and the first battery pack 11 through the first bridge arm 20 and the second bridge arm to form a first heating circuit, connecting the first energy storage circuit and the second battery pack 12 to form a second heating circuit, and connecting the first energy storage circuit, the first battery pack 11, and the second battery pack 12 to form a third heating circuit, as well as the control method of the controller, can be referred to the relevant descriptions in the above embodiments, and will not be repeated below.

[0199] 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, wherein the battery comprises a first battery pack and a second battery pack connected in series, the battery heating circuit comprising: The first switching circuit includes a first connection point, a second connection point, and a third connection point that are interconnected by a first switching element. The first connection point is connected to the positive terminal of the battery, and the second connection point is connected to the negative terminal of the battery. The second switching circuit includes a fourth connection point, a fifth connection point, and a sixth connection point that are interconnected by a second switching element. The fourth connection point is connected to the positive or negative terminal of the battery, and the fifth connection point is connected to the midpoint between the first battery pack and the second battery pack. A first energy storage circuit, wherein a first end of the first energy storage circuit is connected to the third connection point and a second end is connected to the sixth connection point; a first switching circuit and a second switching circuit are configured to connect the first battery pack to the first energy storage circuit to form a first heating circuit, connect the second battery pack to the first energy storage circuit to form a second heating circuit, and connect the first battery pack and the second battery pack to the first energy storage circuit to form a third heating circuit.

2. The battery heating circuit according to claim 1, wherein, The first switching circuit includes at least one first bridge arm, the two ends of which are respectively connected to the first connection point and the second connection point. The first bridge arm includes a first upper bridge arm and a first lower bridge arm connected in series. The midpoint between the first upper bridge arm and the first lower bridge arm serves as the third connection point and is connected to the first energy storage circuit.

3. The battery heating circuit according to claim 1 or 2, wherein the first energy storage circuit includes an inductor.

4. The battery heating circuit according to claim 2 or 3, wherein, The number of first bridge arms is multiple, and the multiple first bridge arms are connected in parallel. The first energy storage circuit includes multiple first inductors connected in parallel, and the multiple first inductors and the multiple first bridge arms are connected in a one-to-one correspondence.

5. The battery heating circuit according to claim 4, wherein, The plurality of first bridge arms and the plurality of first inductors are motors connected to the battery, wherein the plurality of first bridge arms are multi-phase bridge arms of the motors and the plurality of first inductors are motor windings of the motors.

6. The battery heating circuit according to claim 4 or 5, wherein, The first energy storage circuit further includes a second inductor, which is connected in series with a plurality of the first inductors that are connected in parallel.

7. The battery heating circuit according to any one of claims 1-6, wherein the second switching circuit includes a second bridge arm, the two ends of the second bridge arm are respectively connected to the fourth connection point and the fifth connection point, the second switching branch includes a second upper bridge arm and a second lower bridge arm connected in series, and the midpoint between the second upper bridge arm and the second lower bridge arm is connected to the first energy storage circuit as the sixth connection point.

8. The battery heating circuit according to claim 7, wherein the first switching circuit includes a first bridge arm and the second switching circuit includes a second bridge arm, the second upper bridge arm is connected to the midpoint between the first battery pack and the second battery pack, and the second lower bridge arm is connected to the negative terminal of the battery. The first heating circuit includes: First upper bridge arm, first energy storage circuit, second upper bridge arm, and first battery pack; The second heating circuit includes: a first lower bridge arm, a first energy storage circuit, a second upper bridge arm, and a second battery pack; The third heating circuit includes: a first upper bridge arm, a first energy storage circuit, a second lower bridge arm, a first battery pack, and a second battery pack.

9. The battery heating circuit according to claim 7, wherein the first switching circuit includes a first bridge arm and the second switching circuit includes a second bridge arm, the second upper bridge arm is connected to the positive terminal of the battery, and the second lower bridge arm is connected to the midpoint between the first battery pack and the second battery pack. The first heating circuit includes: The first upper bridge arm, the first energy storage circuit, the second lower bridge arm, and the first battery pack; The second heating circuit includes: a first lower bridge arm, a first energy storage circuit, a second lower bridge arm, and a second battery pack; The third heating circuit includes: a first lower bridge arm, a first energy storage circuit, a second upper bridge arm, a first battery pack, and a second battery pack.

10. The battery heating circuit according to any one of claims 1-9, wherein, Also includes: A second energy storage circuit, wherein a first terminal of the second energy storage circuit is connected to the positive terminal of the battery, and a second terminal of the second energy storage circuit is connected to the negative terminal of the battery.

11. The battery heating circuit according to claim 10, wherein, The first energy storage circuit includes at least one inductor, and the second energy storage circuit includes a capacitor.

12. A battery system, wherein, include: The battery includes a first battery pack and a second battery pack connected in series. as well as The battery heating circuit according to any one of claims 1-11.

13. An electrical appliance, wherein, Includes the battery system of claim 12, wherein the battery system supplies power to the electrical device.

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