Energy storage device heating circuit, control method therefor, and controller

Abstract

The present application relates to the technical field of energy storage devices. Disclosed are an energy storage device heating circuit, a control method therefor, and a controller. The energy storage device heating circuit of the present application comprises: a motor controller, a first busbar terminal of the motor controller being electrically connected to negative terminals of first energy storage elements by means of a first switch, and a second busbar terminal of the motor controller being electrically connected to positive terminals of second energy storage elements by means of a second switch; a motor, a busbar terminal of the motor being electrically connected to a connection point by means of a third switch; and at least two energy storage groups connected in parallel. Each energy storage group comprises one first energy storage element, one second energy storage element, one second switch and one third switch, wherein a positive terminal of each first energy storage element is electrically connected to the connection point, and a negative terminal of each second energy storage element is electrically connected to the connection point.

Description

Energy storage device heating circuit, control method and controller thereof Cross-reference to Related Applications

[0001] This application claims priority to Chinese Patent Application No. 202411380842.4, filed on September 29, 2024, entitled “Energy storage device heating circuit, control method and controller thereof”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of energy storage devices, in particular to an energy storage device heating circuit, a control method and a controller thereof. BACKGROUND

[0003] With the widespread use of new energy, battery packs can be used as power sources in various fields. The performance of the battery pack will be affected when used as a power source in different environments. For example, the performance of the battery pack in a low-temperature environment will decrease to a greater extent than in a normal temperature environment. For example, the discharge capacity of the battery pack at zero temperature will decrease with the decrease of temperature. Under the condition of-30℃, the discharge capacity of the battery pack is basically 0, which causes the battery pack to be unable to use. In order to use the battery pack in a low-temperature environment, the battery pack needs to be preheated before use. SUMMARY

[0004] In a first aspect, the present application provides an energy storage device heating circuit, comprising: a motor controller, a first bus end of the motor controller being electrically connected to a negative electrode end of a first energy storage element through a first switch, a second bus end of the motor controller being electrically connected to a positive electrode end of a second energy storage element through a second switch; a motor, a bus end of the motor being electrically connected to a connection point through a third switch; and at least two parallel energy storage groups, each energy storage group comprising a first energy storage element, a second energy storage element, a second switch, and a third switch, wherein the positive electrode end of the first energy storage element is electrically connected to the connection point; and the negative electrode end of the second energy storage element is electrically connected to the connection point.

[0005] In the technical solution of the present application, the connection point between the first and second energy storage elements in each energy storage group and the motor each have a current loop. In the energy storage device heating process, the working state of the energy storage device heating circuit can be enriched by using the circuit between the connection point and the motor, an oscillating current is generated between the two energy storage elements, the strength of the oscillating current is improved, and thus the heating speed of the energy storage device is improved, which helps to improve the performance of the energy storage device in a low-temperature environment. By controlling the switches in each energy storage group, one or more energy storage units can be selectively involved in the energy storage device heating, which improves the flexibility and convenience of the energy storage device heating. The present application is also applicable to scenarios with parallel energy storage groups, thereby expanding the application range.

[0006] In some embodiments, the first energy storage element includes at least one energy storage unit group, and the second energy storage element includes at least one energy storage unit group, each of the energy storage unit groups including at least two energy storage units in parallel.

[0007] In the technical solution of the embodiments of the present application, the first energy storage element and the second energy storage element include a plurality of energy storage units in parallel, which can improve the current intensity, improve the heating speed of the energy storage device, and increase the number of energy storage units that can be heated simultaneously. In addition, such a circuit can help adapt to the specific structure of the energy storage device that needs to be heated, and improve the flexibility of the deployment of the energy storage device heating circuit and the compatibility with the energy storage device.

[0008] In some embodiments, the positive terminal of the first energy storage element is electrically connected to the positive terminal of the second energy storage element through a fourth switch, the negative terminal of the first energy storage element is electrically connected to the negative terminal of the second energy storage element through a fifth switch, and the positive terminal of the first energy storage element and the negative terminal of the second energy storage element include a sixth switch, wherein the fifth switch is located between the connection point and the negative terminal of the first energy storage element.

[0009] In the technical solution of the embodiments of the present application, the circuit structure for switching the first energy storage element and the second energy storage element between parallel and series states is provided, thereby improving the flexibility of the state control of the energy storage device heating circuit.

[0010] In some embodiments, the energy storage device heating circuit meets at least one of the following conditions: in a non-heating mode, the fourth switch and the fifth switch are closed, and the third switch and the sixth switch are open; or in a heating mode, the fourth switch and the fifth switch are open, and the third switch and the sixth switch are closed.

[0011] In the technical solution of the embodiments of the present application, by controlling the state of the switch, the first energy storage element and the second energy storage element are switched between parallel and series states, thereby facilitating switching to the corresponding switch state according to the heating requirement, and improving the convenience of the state control of the energy storage device heating circuit.

[0012] In some embodiments, the second switch of one energy storage group is a main relay of the electric drive assembly.

[0013] In the technical solution of the embodiments of the present application, the main relay is used as the second switch of one energy storage group, which can reduce the number of additional switches, and reduce the cost and complexity of circuit modification.

[0014] In some embodiments, the number of energy storage groups is 2, and the energy storage device heating circuit further includes a potential flattening module located between the two energy storage groups.

[0015] The potential flattening module can balance the potentials of different energy storage units, improve the balance degree of the potentials, help to improve the available time length of the energy storage device heating circuit for performing heating, and improve the service life of the energy storage device.

[0016] In some embodiments, the potential flattening module includes at least one switch and at least one resistor.

[0017] In the technical solution of the embodiments of the present application, the potential flattening module includes a resistor, which can reduce the current passing through the potential flattening module, avoid excessive current due to excessive voltage difference on both sides, and improve the safety of the energy storage device and the circuit.

[0018] In some embodiments, the potential flattening module includes a first type of potential flattening module located between the positive terminals of two second energy storage elements.

[0019] In the technical solution of the embodiments of the present application, the first type of potential flattening module can balance the potentials between the energy storage groups, and improve the balance degree of the potentials.

[0020] In some embodiments, the potential flattening module includes a second type of potential flattening module located between the connection points belonging to two energy storage groups.

[0021] In the technical solution of the embodiments of the present application, the second type of potential flattening module can balance the potentials between the first energy storage elements belonging to different energy storage groups, and improve the balance degree of the potentials.

[0022] In some embodiments, the energy storage device heating circuit further includes a pre-charge circuit of the main relay in parallel with the main relay.

[0023] In the technical solution of the embodiments of the present application, the pre-charge circuit of the main relay can be used to realize the electrical connection between the energy storage group with the main relay as the second switch and the motor controller, facilitate the potential balance between the energy storage group with the main relay as the second switch and other energy storage groups, reduce the number of first type of potential flattening modules that need to be set in the circuit, and reduce the circuit cost.

[0024] In some embodiments, the energy storage device heating circuit further includes a seventh switch located between the parallel circuit of the pre-charge circuit and the main relay close to the bus end of the motor controller and the first bus end of the motor controller.

[0025] In the technical solution of the embodiments of the present application, the seventh switch is separately provided to control the on-off of the positive terminals of all energy storage groups and the motor controller, so that in the energy storage group with the main relay as the second switch, the main relay can only be used to control whether the energy storage group participates in heating, thereby further improving the flexibility of the energy storage device heating circuit.

[0026] In some embodiments, the energy storage device heating circuit, in the non-heating mode, the seventh switch and the first switch are closed, and the second switch and the third switch are open. The technical scheme of the embodiment of the application can improve the convenience of switching the energy storage device heating circuit between the heating mode and the non-heating mode.

[0027] In some embodiments, after the energy storage device heating circuit leaves the heating mode, the potential flattening module is turned on. In the technical scheme of the embodiment of the application, after the energy storage device heating circuit leaves the heating mode, the potential flattening module is used to balance the potentials between the energy storage groups or the energy storage elements, which is beneficial to the normal operation of the energy storage device in the non-heating mode (for example, the electric drive driving mode) and the normal use of the circuit when entering the energy storage device heating mode next time.

[0028] In some embodiments, the number of energy storage groups is greater than 2, and after the energy storage device heating circuit leaves the heating mode, the pre-charge circuit is turned on, and each energy storage group is turned on with the energy storage group where the main relay is located one by one.

[0029] In the technical scheme of the embodiment of the application, the pre-charge module is turned on, and the second switch is turned on one by one, which can balance the potentials between the energy storage groups two by two. Through multiple potential balancing operations, the potential difference of all energy storage groups is within the required range, which is beneficial to the normal operation of the energy storage device in the non-heating mode (for example, the electric drive driving mode) and the normal use of the circuit when entering the heating mode next time.

[0030] In some embodiments, the motor controller comprises a bridge arm converter, and the bridge arm converter comprises: a plurality of bridge arm branches arranged in parallel, each bridge arm branch comprising a first switch circuit and a second switch circuit connected in series, the first switch circuit being connected with a positive electrode end of the second energy storage element, and the second switch circuit being connected with a negative electrode end of the first energy storage element.

[0031] In the technical scheme of the embodiment of the application, the motor controller comprises a bridge arm converter, and the control function of the electric drive assembly is used to realize self-heating of the energy storage device by using the motor. In the self-heating process, the electric drive does not generate torque, and the NVH (Noise, Vibration, Harshness, noise, vibration and harshness) is good. No additional power module and switch control circuit need to be arranged, and the circuit cost is saved.

[0032] In some embodiments, for at least one energy storage group, the energy storage device heating circuit is in a first phase, the energy storage device heating circuit is in the first phase, the first switch circuit is turned on, the second switch circuit is turned off, and the second energy storage element charges the motor; the energy storage device heating circuit is in a second phase, the first switch circuit is turned off, the second switch circuit is turned on, and the motor discharges the first energy storage element; the energy storage device heating circuit is in a third phase, the first switch circuit is turned off, the second switch circuit is turned on, and the first energy storage element charges the motor; the energy storage device heating circuit is in a fourth phase, the first switch circuit is turned on, the second switch circuit is turned off, and the motor discharges the second energy storage element.

[0033] In the technical solution of the embodiments of the present application, the energy storage device heating circuit has four working phases, and the current repeatedly oscillates among the second energy storage element, the motor and the first energy storage element, which enriches the working state of the energy storage device heating circuit, improves the strength of the oscillating current, and thus improves the heating speed of the energy storage device, which helps to improve the performance of the energy storage device in a low temperature environment.

[0034] In some embodiments, the energy storage device heating circuit alternately stays in a first state and a second state in the heating mode, wherein the energy storage device heating circuit alternately stays in a first phase and a second phase in the first state, and the energy storage device heating circuit stays in the first state for a first duration; the energy storage device heating circuit alternately stays in a third phase and a fourth phase in the second state, and the energy storage device heating circuit stays in the second state for a second duration.

[0035] In the technical solution of the embodiments of the present application, the first and second phases are cycled in the first duration, and the third and fourth phases are cycled in the second duration, so that the energy storage device heating circuit has a current cycle with the first and second durations as the cycle length, which improves the current strength in the current oscillation process, and thus further improves the heating speed of the energy storage device, which helps to improve the performance of the energy storage device in a low temperature environment.

[0036] In some embodiments, the energy storage device includes a battery, the first energy storage element uses a battery pack as an energy storage unit, and the second energy storage element uses a battery pack energy storage unit. The technical solution of the embodiments of the present application improves the heating speed of the battery pack, helps to improve the performance of the battery pack in a low temperature environment, improves the flexibility and convenience of battery pack heating, and is also applicable to scenarios with parallel battery packs, thereby expanding the application range.

[0037] In a second aspect, the application provides a control method for a heating circuit of an energy storage device, wherein the heating circuit of the energy storage device comprises: a motor controller, a first bus end of the motor controller being electrically connected to a negative end of a first energy storage element through a first switch, a second bus end of the motor controller being electrically connected to a positive end of a second energy storage element through a second switch; a motor, a bus end of the motor being electrically connected to a connection point through a third switch; and at least two parallel energy storage groups, each energy storage group comprising a first energy storage element, a second energy storage element, a second switch, and a third switch, wherein a positive end of the first energy storage element is electrically connected to the connection point, and a negative end of the second energy storage element is electrically connected to the connection point; the control method comprises: for at least one energy storage group, controlling the first switch, the second switch, and the third switch to be closed, so that the heating circuit of the energy storage device is in a heating mode.

[0038] In the technical solution of the embodiment of the application, the connection point between the first and second energy storage elements and the motor form a current loop, and in the energy storage device heating process, the working state of the heating circuit of the energy storage device can be enriched by using the circuit between the connection point and the motor, an oscillation current is generated between the two energy storage elements, the strength of the oscillation current is improved, and thus the heating speed of the energy storage device is improved, which helps to improve the performance of the energy storage device in a low-temperature environment; by controlling the switches in each energy storage group, one or more energy storage units can be selected to participate in the heating of the energy storage device, the flexibility and convenience of the energy storage device heating are improved, and the application range is also expanded.

[0039] In some embodiments, the motor controller comprises a bridge arm converter, the bridge arm converter comprising: a plurality of bridge arm branches arranged in parallel, each bridge arm branch comprising a first switch circuit and a second switch circuit connected in series, the first switch circuit being connected to the positive end of the second energy storage element, and the second switch circuit being connected to the negative end of the first energy storage element; the control method further comprises: for at least one energy storage group, controlling the first switch circuit to be turned on and the second switch circuit to be turned off, so that the heating circuit is in a first stage, wherein in the first stage, the second energy storage element charges the motor; controlling the first switch circuit to be turned off and the second switch circuit to be turned on, so that the heating circuit is in a second stage, wherein in the second stage, the motor discharges the first energy storage element; controlling the first switch circuit to be turned off and the second switch circuit to be turned on, so that the heating circuit is in a third stage, wherein in the third stage, the first energy storage element charges the motor; and controlling the first switch circuit to be turned on and the second switch circuit to be turned off, so that the heating circuit is in a fourth stage, wherein in the fourth stage, the motor discharges the second energy storage element.

[0040] In the technical solution of the embodiment of the application, the control current repeatedly oscillates between the second energy storage element, the motor and the first energy storage element, which enriches the working state of the energy storage device heating circuit, improves the intensity of the oscillation current, and thus improves the heating speed of the energy storage device, and helps to improve the performance of the energy storage device in a low-temperature environment.

[0041] In some embodiments, the control method further comprises: controlling the energy storage device heating circuit to alternately be in the first state and the second state, comprising: controlling the energy storage device heating circuit to be in the first state for a first time length; and controlling the energy storage device heating circuit to be in the second state for a second time length, wherein the energy storage device heating circuit is controlled to be in the first state by controlling the energy storage device heating circuit to alternately be in the first stage and the second stage; and the energy storage device heating circuit is controlled to be in the second state by controlling the energy storage device heating circuit to alternately be in the third stage and the fourth stage.

[0042] In the technical solution of the embodiment of the application, the energy storage device heating circuit is controlled to cycle the first stage and the second stage for the first time length, and to cycle the third stage and the fourth stage for the second time length, so that the energy storage device heating circuit has a current cycle with the first time length and the second time length as the cycle length, the intensity of the current in the current oscillation process is improved, and thus the heating speed of the energy storage device is further improved, and the performance of the energy storage device in a low-temperature environment is improved.

[0043] In some embodiments, the positive terminal of the first energy storage element and the positive terminal of the second energy storage element are electrically connected through a fourth switch; the negative terminal of the first energy storage element and the negative terminal of the second energy storage element are electrically connected through a fifth switch; and the positive terminal of the first energy storage element and the negative terminal of the second energy storage element comprise a sixth switch, wherein the fifth switch is located between the connection point and the negative terminal of the first energy storage element; the control method further comprises: controlling the fourth switch and the fifth switch to be closed, and controlling the third switch and the sixth switch to be opened, so that the energy storage device heating circuit is in a non-heating mode; or controlling the fourth switch and the fifth switch to be opened, and controlling the third switch and the sixth switch to be closed, so that the energy storage device heating circuit is in a heating mode.

[0044] In the technical solution of the embodiment of the application, the state of the energy storage device heating circuit switch is controlled, so that the first energy storage element and the second energy storage element are switched between the parallel connection state and the series connection state, thereby facilitating switching to the corresponding switch state according to the heating demand, and improving the convenience of the state control of the energy storage device heating circuit.

[0045] In some embodiments, the number of energy storage groups in the energy storage device heating circuit is 2; the energy storage device heating circuit further comprises: a potential flattening module located between the two energy storage groups; the energy storage device heating circuit further comprises: a potential flattening module located between the two energy storage groups; and the control method further comprises: after controlling the energy storage device heating circuit to leave the heating mode, controlling the potential flattening module to be turned on.

[0046] In the technical solution of the embodiment of the application, the potential flattening module is controlled, the potentials of different energy storage units are balanced, the balancing degree of the potentials is improved, the available time length of the energy storage device heating circuit for executing the energy storage device heating is improved, and the service life of the energy storage device is improved.

[0047] In some embodiments, the second switch of one energy storage group is a main relay of the electric drive assembly; the energy storage device heating circuit further comprises: a pre-charge circuit of the main relay, which is connected in parallel with the main relay; and a seventh switch, which is located between the parallel circuit of the pre-charge circuit and the main relay and the bus end of the motor controller, and between the seventh switch and the first bus end of the motor controller; the control method further comprises: controlling the seventh switch and the first switch to be closed, and the second switch and the third switch to be opened, so that the energy storage device heating circuit is in a non-heating mode.

[0048] In the technical solution of the embodiment of the application, the convenience of switching the energy storage device heating circuit between the heating mode and the non-heating mode is improved by controlling the switches.

[0049] In some embodiments, the energy storage device heating circuit comprises at least three parallel energy storage groups, the second switch of one energy storage group is a main relay of the electric drive assembly; the energy storage device heating circuit further comprises: a pre-charge circuit of the main relay, which is connected in parallel with the main relay; and a seventh switch, which is located between the parallel circuit of the pre-charge circuit and the main relay and the bus end of the motor controller, and between the seventh switch and the first bus end of the motor controller; the control method further comprises: after controlling the energy storage device heating circuit to leave the heating mode, the seventh switch is opened, the pre-charge circuit is controlled to be turned on, and each energy storage group is controlled to be turned on one by one with the energy storage group in which the main relay is located.

[0050] In the technical solution of the embodiment of the application, the pre-charge module is controlled to be turned on, and the second switches are controlled to be turned on one by one, so that the potentials between the energy storage groups are balanced, the potential difference of all the energy storage groups is within a required range through multiple potential balancing operations, the normal operation of the energy storage device in the non-heating mode (for example, the electric drive driving mode) is facilitated, and the normal use of the circuit when entering the heating mode next time is facilitated.

[0051] In a third aspect, the application provides a controller for an energy storage device heating circuit, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute any of the control methods for the energy storage device heating circuit based on instructions stored in the memory.

[0052] In the technical scheme of the embodiment of the present application, the connection point between the first and second energy storage elements and the motor has a current loop, under the control of the controller, in the heating process, the energy storage device heating circuit can enrich the working state of the energy storage device heating circuit by using the circuit between the connection point and the motor, generate an oscillating current between the two groups of energy storage elements, improve the strength of the oscillating current, thereby improve the heating speed of the energy storage device, and help to improve the performance of the energy storage device in a low temperature environment. Through the control of the switches in each energy storage group, one or more groups of energy storage units can be selected to participate in heating, improving the flexibility and convenience of heating, and also applicable to the scene where there are parallel energy storage devices, expanding the application range.

[0053] In a fourth aspect, the present application provides a computer readable storage medium having computer program instructions stored thereon, which, when executed by a processor, implement any of the above control methods for an energy storage device heating circuit.

[0054] In the technical scheme of the embodiment of the present application, the connection point between the first and second energy storage elements and the motor has a current loop, through running the computer program instructions stored on the storage medium, in the heating process, the energy storage device heating circuit can enrich the working state of the heating circuit by using the circuit between the connection point and the motor, generate an oscillating current between the two groups of energy storage elements, improve the strength of the oscillating current, thereby improve the heating speed, and help to improve the performance of the energy storage device in a low temperature environment. Through the control of the switches in each energy storage group, one or more groups of energy storage units can be selected to participate in heating, improving the flexibility and convenience of heating, and also applicable to the scene where there are parallel energy storage devices, expanding the application range.

[0055] In a fifth aspect, the present application provides a computer program product comprising computer programs or instructions, which, when executed by a processor, implement any of the above control methods for an energy storage device heating circuit.

[0056] In the technical scheme of the embodiment of the present application, the connection point between the first and second energy storage elements and the motor has a current loop, through running the computer program instructions stored on the storage medium, in the heating process, the energy storage device heating circuit can enrich the working state of the heating circuit by using the circuit between the connection point and the motor, generate an oscillating current between the two groups of energy storage elements, improve the strength of the oscillating current, thereby improve the heating speed, and help to improve the performance of the energy storage device in a low temperature environment. Through the control of the switches in each energy storage group, one or more groups of energy storage units can be selected to participate in heating, improving the flexibility and convenience of heating, and also applicable to the scene where there are parallel energy storage devices, expanding the application range.

[0057] The above description is only a summary of the technical solutions of the present application. In order to enable one skilled in the art to better understand the technical means of the present application, the present application can be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0058] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of preferred embodiments, and are not meant to limit the present application. Moreover, the same reference numerals in all the drawings represent the same or similar elements. In the drawings:

[0059] FIG. 1 is a schematic diagram of a storage device heating circuit in some embodiments of the present application.

[0060] FIG. 2 is a schematic diagram of a storage device heating circuit in some embodiments of the present application.

[0061] FIG. 3 is a schematic diagram of a storage device heating circuit in some embodiments of the present application.

[0062] FIG. 4 is a first stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0063] FIG. 5 is a second stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0064] FIG. 6 is a third stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0065] FIG. 7 is a fourth stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0066] FIG. 8 is a schematic diagram of a storage device heating circuit in some embodiments of the present application.

[0067] FIG. 9 is a first stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0068] FIG. 10 is a second stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0069] FIG. 11 is a third stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0070] FIG. 12 is a fourth stage current flow diagram of a storage device heating circuit in some embodiments of the present application.

[0071] FIG. 13 is a schematic diagram of a storage device heating circuit in some embodiments of the present application.

[0072] FIG. 14 is a schematic diagram of a stored energy device heating circuit in some embodiments of the application.

[0073] FIG. 15 is a schematic diagram of a stored energy device heating circuit in some embodiments of the application.

[0074] FIG. 16 is a flowchart of a control method for a stored energy device heating circuit in some embodiments of the application.

[0075] FIG. 17 is a flowchart of a control method for a stored energy device heating circuit in some embodiments of the application.

[0076] FIG. 18 is a schematic diagram of a controller in some embodiments of the application.

[0077] FIG. 19 is a schematic diagram of a controller in some embodiments of the application. DETAILED DESCRIPTION

[0078] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0079] 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 belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "comprising" and "having," and any variations thereof, as used in the specification and claims and the aforementioned drawings, are intended to cover not exclusive inclusions.

[0080] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0081] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0082] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0083] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0084] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0085] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0086] To solve the problem of self-heating of the battery pack, the related art uses a circuit including a bridge arm converter, a motor winding, and a battery pack, and through a discharging process of the battery pack, the battery pack repeatedly flows between the motor winding and the battery pack. The battery pack is in an alternating state of rapid charging and discharging. Due to the existence of the internal resistance of the battery pack, a large amount of heat is generated inside, and the temperature rises rapidly. However, in such a scheme, the current flowing through the battery pack is small, the heating speed of the battery pack is full, and the self-heating efficiency of the battery is low.

[0087] To solve the above problems, the application provides a kind of energy storage equipment heating circuit and its control method and controller.In the energy storage equipment heating circuit of the application, by decoupling battery pack, it is divided into two groups, while realizing the charging and discharging of current between battery pack and motor, it also realizes the mutual charging and discharging between two battery packs, so that the shock current is generated between battery packs, thereby improving the shock current, to achieve the purpose of efficient heating of battery pack.

[0088] The battery of the application can be applied to scenarios such as mobile phones, tablets, laptops, electric toys, power tools, electric cars, electric cars, ships, spacecraft, etc.The electric toy can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric plane toys, etc.Spacecraft can include airplanes, rockets, space shuttles and spacecraft, etc.The switch in the following of the application can be realized in various ways, such as a relay.

[0089] The following examples are for convenience, and the application is applied to the self-heating of the energy storage device of the electric vehicle.In some embodiments, the energy storage device is a battery.

[0090] The schematic diagram of some embodiments of the energy storage device heating circuit of the application is shown in Figure 1.

[0091] The energy storage device heating circuit includes a plurality of energy storage groups, and a motor controller 11 and a motor 12.Each energy storage group includes a first energy storage element, a second energy storage element, a second switch, and a third switch, for example, the circuit of two energy storage groups shown in Figure 1, the first energy storage group includes a first energy storage element BT11, a second energy storage element BT21, a second switch S21, and a third switch S31;The second energy storage group includes a first energy storage element BT12, a second energy storage element BT22, a second switch S22, and a third switch S32.The working state of the second switch and the third switch can be switched to selectively heat the energy storage unit in each energy storage group, for example, the second switch S21 and the third switch S31 are turned on, and the second switch S22 and the third switch S32 are turned off, only the first energy storage group participates in heating;The second switch S22 and the third switch S32 are turned on, and the second switch S21 and the third switch S31 are turned off, only the second energy storage group participates in heating;The second switch S21, S22 and the third switch S31, S31 are turned on, and the first and second energy storage groups participate in heating.In some embodiments, the above-mentioned energy storage unit can be a battery pack.

[0092] In each energy storage group, the first energy storage element and the second energy storage element are connected in series through a connection point, wherein the positive terminal of the first energy storage element is electrically connected to the connection point;The negative terminal of the second energy storage element is electrically connected to the connection point.

[0093] In some embodiments, the first and second energy storage elements each comprise at least one energy storage unit. For example, as shown in FIG. 1, the first and second energy storage elements each comprise one energy storage unit.

[0094] In some embodiments, the first energy storage element comprises at least one energy storage unit group, and the second energy storage element comprises at least one energy storage unit group, each energy storage unit group comprising at least two energy storage units connected in parallel. For example, as shown in FIG. 3, the first energy storage element comprises one energy storage unit group, which comprises energy storage unit BT101 and energy storage unit BT201 connected in parallel; and the second energy storage element comprises one energy storage unit group, which comprises energy storage unit BT102 and energy storage unit BT202 connected in parallel. For the sake of clarity of the circuit diagram, only one energy storage unit group is shown in FIG. 3, and other at least one energy storage unit group in the circuit is not shown in the figure. The number of energy storage units in the first and second energy storage elements in other energy storage unit groups and the connection mode can be the same as or different from those in the shown energy storage unit group.

[0095] The motor controller 11 and the motor 12 are components of the electric drive assembly. The first bus end of the motor controller 11 is electrically connected to the negative end of the first energy storage element through the first switch S1, and the second bus end of the motor controller 11 is electrically connected to the positive end of the second energy storage element through the second switch. The branches of the motor 12 are respectively connected to the motor controller 11, and each branch comprises a resistor and an inductor. For example, as shown in FIG. 1, the three branches respectively comprise resistor R1 and inductor L1, resistor R2 and inductor L2, and resistor R3 and inductor L3. The bus end (stator end) of the motor 12 is electrically connected to the connection point between the first energy storage element and the second energy storage element through the third switch S3.

[0096] In the circuit, when in the self-heating state of the energy storage device, the first, second and third switches in at least one energy storage unit group are all closed. In some embodiments, taking the first, second and third switches of the first energy storage unit group as an example, the flow direction of the current comprises: flowing from BT21 to the motor through S21, and flowing from the motor to BT11 through S31, thereby realizing the flow of current from BT21 to BT11. In some embodiments, the flow direction of the current comprises: flowing from BT11 to the motor through S31, and flowing from the motor to BT21 through S21, thereby realizing the flow of current from BT11 to BT21. In some embodiments, the flow direction of the current comprises: flowing from BT21 to the motor through S21, flowing from the motor to BT11 through S31, flowing from BT11 to the motor through S3, and flowing from the motor to BT21 through S21, thereby completing the oscillation of the current between BT21 and BT11 through the above-mentioned circulation.

[0097] In some embodiments, the first switch and the second switch of one of the energy storage unit groups can be the main relay of the electric drive assembly, thereby fully utilizing the original circuit structure and reducing the cost.

[0098] In the technical solution of the embodiment, the connection point between the first and second energy storage elements and the motor has a current loop, and during the heating of the energy storage device, the working state of the energy storage device heating circuit can be enriched by using the circuit between the connection point and the motor, an oscillation current is generated between the two groups of energy storage elements, the strength of the oscillation current is improved, and thus the heating speed is improved, which helps to improve the performance of the energy storage device in a low-temperature environment; the control of the switches in each energy storage group can selectively enable one or more groups of energy storage units to participate in heating, thereby improving the flexibility and convenience of heating; it is helpful to adapt to the specific structure of the energy storage device to be heated, improve the flexibility of the deployment of the energy storage device heating circuit, and improve the compatibility with the energy storage device; it is also applicable to scenarios where there are parallel energy storage units, thereby expanding the application range.

[0099] In some embodiments, in each energy storage group, the first and second energy storage elements can be switched to a parallel connection state in addition to the series connection mode.

[0100] In the parallel connection state, the circuit is in an electric drive mode, and at this time, there is no current flowing through the third switch of the energy storage group. In order to make the circuit diagram clear, only one energy storage group is shown in FIG. 2, and at least one other energy storage group in the circuit is not shown in the figure. For example, in the energy storage device heating circuit shown in FIG. 2, the positive terminal of the first energy storage element BT1 is electrically connected to the positive terminal of the second energy storage element BT2 through the fourth switch S4, and the negative terminal of the first energy storage element BT1 is electrically connected to the negative terminal of the second energy storage element BT2 through the fifth switch S5. In addition, between the first energy storage element and the second energy storage element in series, the sixth switch S6 is included between the positive terminal of the first energy storage element and the negative terminal of the second energy storage element. The fifth switch is located between the connection point and the negative terminal of the first energy storage element, thereby ensuring that in the case where the fourth and fifth switches are closed and the sixth switch is open, the parallel circuit of the first energy storage element BT1 and the second energy storage element BT2 is connected to the motor controller through the switches S1 and S2; in the case where the fourth and fifth switches are open and the sixth switch is closed, the series circuit of the first energy storage element BT1 and the second energy storage element BT2 can also be connected to the motor controller through S1 and S2.

[0101] In some embodiments, taking the circuit shown in FIG. 2 as an example, in the non-heating mode of the energy storage device heating circuit, the fourth switch and the fifth switch are closed, the third switch and the sixth switch are open, the first and second energy storage elements are in parallel, and there is no current on the connection line between the connection point and the motor; in the heating mode of the energy storage device heating circuit, the fourth switch and the fifth switch are open, the third switch and the sixth switch are closed, the first and second energy storage elements are in series, and there is current on the connection line between the connection point and the motor.

[0102] In the technical solution of the embodiment of the application, the state of the switch is controlled, so that the first energy storage element and the second energy storage element are switched between the parallel and series states, thereby facilitating switching to the corresponding switch state according to the heating requirement, and the convenience of state control of the energy storage device heating circuit is improved.

[0103] The connection mode of the first energy storage element and the second energy storage element of a group of energy storage groups in the embodiment shown in FIG. 2 is also applicable to other energy storage groups. By switching the first energy storage element and the second energy storage element of all energy storage groups in the circuit to the parallel mode, the energy storage device heating circuit exits the heating mode and enters the non-heating mode, for example, the electric drive driving mode.

[0104] Each embodiment applicable in the context of the present application and the extendable embodiments are not described here again.

[0105] In some embodiments, the motor controller 11 includes a bridge arm converter, which includes a plurality of bridge arm branches arranged in parallel, for example, as shown in FIGS. 1-15, including three bridge arms, each bridge arm branch includes a first switch circuit and a second switch circuit connected in series, each switch circuit includes a triode (for example, V1-V6) and a diode (D1-D6). The first switch circuit (including V1-D1, V2-D2, V3-D3) is connected to the positive terminal of the second energy storage element, and the second switch circuit (including V4-D4, V5-D5, V6-D6) is connected to the negative terminal of the first energy storage element.

[0106] In the technical solution of the embodiment of the application, the motor controller includes a bridge arm converter, and the self-heating of the motor is realized by using the control function of the electric drive assembly. The self-heating process does not generate torque for the electric drive, and the NVH performance is good. No additional power module and switch control circuit need to be arranged, and the circuit cost is saved.

[0107] The conduction state of the switch circuit is controlled by controlling the conduction state of the triode (V1-V6) on the switch circuit, thereby realizing the control of the current flow direction in the energy storage device heating circuit. In some embodiments, taking the circuit shown in FIG. 3 as an example, as shown in FIGS. 4-7, the current flow direction of the energy storage device heating circuit is divided into four stages. Similar to FIG. 3, for the clarity of the circuit diagram, only one group of energy storage groups is shown in FIGS. 4-7, and at least one group of energy storage groups in the circuit is not shown in the figure.

[0108] As shown in FIG. 4, in the first stage STEP1, the first switch circuit is turned on, and the second switch circuit is turned off, i.e. V1-V3 is turned on, V4-V6 is turned off, and the circuit is turned on through the second energy storage element, the second switch, the first switch circuit, the motor, and the third switch. The current of the second energy storage element (including BT12 and BT22) reaches the motor control circuit through the second switch S2, reaches the motor through the first switch circuit, and completes the charging of the second energy storage element to the motor.

[0109] As shown in FIG. 5, in the second stage STEP2, the first switch circuit is turned off, and the second switch circuit is turned on, i.e. V1-V3 is turned off, V4-V6 is turned on, and the circuit is turned on through the first energy storage element, the second switch, the second switch circuit, the motor, and the third switch. The current of the motor is charged back to the first energy storage element through the connection point.

[0110] As shown in FIG. 6, in the third stage STEP3, the first switch circuit is turned off, and the second switch circuit is turned on, i.e. V1-V3 is turned off, V4-V6 is turned on, and the circuit is turned on through the first energy storage element, the second switch, the second switch circuit, the motor, and the third switch. Since the motor has been discharged in the previous stage, the current flows from the first energy storage element to the motor through the connection point and the third switch at this time, achieving the charging of the motor.

[0111] As shown in FIG. 7, in the fourth stage STEP4, the first switch circuit is turned on, and the second switch circuit is turned off, i.e. V1-V3 is turned on, V4-V6 is turned off, and the circuit is turned on through the second energy storage element, the second switch, the first switch circuit, the motor, and the third switch. The current of the motor is charged back to the second energy storage element through the connection point.

[0112] In the above embodiment, the energy storage device heating circuit has four working stages, and the current repeatedly oscillates between the second energy storage element, the motor, and the first energy storage element, achieving the transfer of electric energy between the first and second energy storage elements, improving the strength of the oscillating current, thereby improving the heating speed and helping to improve the performance of the energy storage device in a low temperature environment.

[0113] In some embodiments, the above four stages can be sequentially executed, and the oscillation of electric energy between the second energy storage element and the first energy storage element is completed once in each cycle.

[0114] In some embodiments, the intensity of the oscillating current can be further increased by controlling the execution order of the four stages. For example, the heating circuit of the energy storage device alternates between a first state and a second state in heating mode. In the first state, the heating circuit alternates between the first stage and the second stage, i.e., STEP1 STEP2 STEP1 STEP2 STEP1 STEP2… In the second state, the heating circuit alternates between the third stage and the fourth stage, i.e., STEP3 STEP4 STEP3 STEP4 STEP3 STEP4…

[0115] The heating circuit of the energy storage device lasts for a first duration T1 in the first state and for a second duration T2 in the second state. The first duration T1 is greater than the time length for executing STEP1 and STEP2 once; the second duration T2 is greater than the time length for executing STEP3 and STEP4 once.

[0116] Based on this embodiment, the charging and discharging frequency of the current between the first and second energy storage elements in the heating circuit of the energy storage device is [1 / (T1+T2)] Hz, which is less than the current flow frequency between the energy storage device and the motor. By superimposing the currents of the two frequencies, a larger oscillating current is generated in the circuit, thereby improving the heating efficiency.

[0117] In some embodiments, the heating circuit of the energy storage device may include a combination of multiple sets of first energy storage elements and second energy storage elements, such as at least two parallel energy storage groups, each energy storage group including a first energy storage element, a second energy storage element, a second switch, and a third switch.

[0118] Taking the heating circuit of the energy storage device as an example, which includes two parallel energy storage groups, as shown in Figure 8, taking the heating of only the first energy storage element BT12 and the second energy storage element BT22 in the second energy storage group as an example, close S22 and S32, and open S21 and S31.

[0119] As shown in Figure 9, in the first stage STEP1, the first switching circuit is turned on and the second switching circuit is turned off, i.e., V1-V3 are turned on and V4-V6 are turned off. The circuit through the second energy storage element BT22, the second switch S22, the first switching circuit, the motor, and the third switch S32 is completed. The current from the second energy storage element BT22 reaches the motor control circuit through the second switch S22, and then reaches the motor through the first switching circuit, completing the charging of the motor.

[0120] As shown in FIG. 10, in the second stage STEP2, the first switch circuit is off, and the second switch circuit is on, that is, V1-V3 is off, and V4-V6 is on. The circuit is on through the first energy storage element BT12, the second switch S22, the second switch circuit, the motor, and the third switch S32. The current of the motor is charged back to the first energy storage element BT12 through the connection point.

[0121] As shown in FIG. 11, in the third stage STEP3, the first switch circuit is off, and the second switch circuit is on, that is, V1-V3 is off, and V4-V6 is on. The circuit is on through the first energy storage element BT12, the second switch S22, the second switch circuit, the motor, and the third switch S32. Since the motor has been discharged in the previous stage, the current flows from the first energy storage element BT12 to the motor through the connection point and the third switch BT32, so as to charge the motor.

[0122] As shown in FIG. 12, in the fourth stage STEP4, the first switch circuit is on, and the second switch circuit is off, that is, V1-V3 is on, and V4-V6 is off. The circuit is on through the second energy storage element BT22, the second switch S22, the first switch circuit, the motor, and the third switch S32. The current of the motor is charged back to the second energy storage element BT22 through the connection point.

[0123] Similarly, if the first energy storage element BT11 and the second energy storage element BT21 in the first energy storage group are heated, S21 and S31 are closed, and S22 and S32 are disconnected. The current flows in the four stages are similar to those in FIGS. 9-12, which will not be described here.

[0124] If the energy storage units in the first energy storage group and the second energy storage group are heated, S21, S31, S22, and S32 are closed. The current flows in the four stages are similar to those in FIGS. 9-12, which will not be described here.

[0125] In the technical scheme of the embodiment, the energy storage device heating circuit can have one or more energy storage groups. Each energy storage group includes a first energy storage element, a second energy storage element, and corresponding second and third switches. Through the control of the switches, one or more energy storage units can be selectively involved in heating, thereby improving the flexibility and convenience of heating.

[0126] In some embodiments, the energy storage units in the first energy storage group and the second energy storage group are left and right energy storage units, respectively. The above-mentioned working modes of heating only the first energy storage group and heating only the second energy storage group can be switched with each other to achieve the effect of heating the left and right energy storage units.

[0127] In some embodiments, similar to the embodiments shown in Figures 4-7, the four stages corresponding to Figures 9-12 can be executed sequentially, and in each cycle, an oscillation of electrical energy between the second energy storage element and the first energy storage element is completed.

[0128] In some embodiments, the intensity of the oscillating current can be further increased by controlling the execution order of the four stages. For example, the heating circuit of the energy storage device alternates between a first state and a second state in heating mode. In the first state, the heating circuit alternates between the first stage and the second stage, i.e., STEP1 STEP2 STEP1 STEP2… In the second state, the heating circuit alternates between the third stage and the fourth stage, i.e., STEP3 STEP4 STEP3 STEP4…

[0129] The heating circuit of the energy storage device lasts for a first duration T1 in the first state and for a second duration T2 in the second state. The first duration T1 is greater than the time length for executing STEP1 and STEP2 once; the second duration T2 is greater than the time length for executing STEP3 and STEP4 once.

[0130] Based on this embodiment, the charging and discharging frequency of the current in the heating circuit of the energy storage device between the first and second energy storage elements is [1 / (T1+T2)] Hz, which is less than the current flow frequency between the energy storage unit and the motor. By superimposing the currents of the two frequencies, a larger oscillating current is generated in the circuit, thereby improving the heating efficiency.

[0131] In some embodiments, the heating circuit of the energy storage device further includes a seventh switch S10, as shown in FIG13. When this switch is turned off, the circuit between all energy storage elements and the motor controller can be disconnected, which is beneficial for controlling the operating state of the circuit. The seventh switch S10 is applicable to each embodiment of the heating circuit of an energy storage device with multiple energy storage groups.

[0132] In some embodiments, the heating circuit of the energy storage device may further include a potential balancing module located between the two energy storage groups. When the heating circuit of the energy storage device leaves the heating mode, the potential balancing module is activated to balance the potentials of the different energy storage groups. This helps to increase the available time for the heating circuit of the energy storage device to perform heating of the energy storage units and improve the service life of the energy storage units. The potential balancing module is applicable to each embodiment of the heating circuit of an energy storage device with two or more energy storage groups.

[0133] In some embodiments, as shown in FIG. 8, the potential flattening module includes at least one switch S7 and at least one resistor R7. The switch S7 is turned on to enable the potential flattening module. The resistor R7 can effectively reduce the current passing through the potential flattening module, avoiding excessive current due to excessive voltage difference on both sides, and improving the safety of the energy storage unit and the circuit.

[0134] As shown in FIG. 8, the switch S71 and the resistor R7 form a first potential flattening module. When the module is turned on, it can flatten the potential of the second energy storage elements BT21 and BT22, and improve the potential balance between the energy storage groups.

[0135] In some embodiments, as shown in FIG. 13, in the energy storage device heating circuit, the second switch of one of the energy storage groups is a main relay, for example, the second switch S21 of the first energy storage group is a main relay. The energy storage device heating circuit can include a pre-charge circuit of the main relay in parallel with the main relay, including a switch S8 and a resistor R8. The pre-charge circuit can be used as a first potential flattening module to flatten the potential between the first and second energy storage groups. For example, when leaving the heating mode, the seventh switch S10 between the parallel circuit of the pre-charge circuit and the main relay and the motor controller is opened, and S21 and S22 are closed, so that a loop is formed between the first and second energy storage groups. In such a circuit, the pre-charge circuit in the device is used to balance the potential between the energy storage groups, reducing the number of additional components needed and reducing the size and cost of the circuit. In addition, the first switch S1 can also be a main relay, and can be connected in parallel with the corresponding pre-charge circuit (including a switch S9 and a resistor R9) to make full use of the original relay and circuit in the device.

[0136] In some embodiments, the energy storage device heating circuit further includes a second potential flattening module for flattening the potential between the first energy storage elements of different energy storage groups after the circuit leaves the heating mode. As shown in FIG. 14, the switch S10 and the resistor R10 form a second potential flattening module. When the module is turned on, it can flatten the potential of the first energy storage elements BT11 and BT12, thereby balancing the potential between the first energy storage elements belonging to different energy storage groups and improving the balance of the potential.

[0137] In some embodiments, the number of energy storage groups in the energy storage device heating circuit can be greater than 2, for example, as shown in FIG. 15, including n energy storage groups, n being a positive integer greater than or equal to 3. The working phase of each energy storage group in the heating mode is similar to that in the embodiments shown in FIGS. 9 to 12, which will not be repeated here. The second switch S21 of the first energy storage group is a main relay +, and the first switch in the circuit is a main relay -. The pre-charge circuit (S8 and R8) is connected in parallel with the second switch S21.

[0138] When the energy storage device heating circuit leaves the heating mode, the switches S10 and S21 are turned off, and the second switches S22-S2n of other energy storage modules are turned off. The switch S8 of the pre-charge circuit is turned on, one of the second switches S22-S2n is turned on, and after the potential of the first energy storage group and the energy storage group with the turned-on second switch is leveled, the second switch is turned off, and another of the second switches S22-S2n is turned on. By turning on the first energy storage group and the other energy storage group one by one, the potential balance between the first energy storage group and each energy storage group is achieved. Through multiple rounds of turning on and turning off the second switches, the potential difference between different energy storage groups is gradually reduced, and when the potential difference is less than 5V, the potential is forced to be leveled, and the potential balance is achieved.

[0139] Based on the circuit in the above-mentioned embodiment, the pre-charge module is turned on, and the second switches are turned on one by one, which can balance the potential between the energy storage groups two by two. Through multiple potential balancing operations, the potential difference between all energy storage groups is within the required range, which is beneficial to the normal operation of the energy storage unit in the non-heating mode (such as the electric drive mode) and the normal use of the circuit in the next heating mode.

[0140] In some embodiments, in the circuit shown in FIG. 15, only one other energy storage group and the energy storage group where the main relay is located are turned on at the same time, so that the excessive current caused by the potential leveling between the energy storage groups without passing through the pre-charge circuit is avoided, and the safety of the circuit is improved.

[0141] The energy storage device heating circuit of the present application is not limited to the embodiments shown in the above figures. Based on the understanding of the circuit, those skilled in the art can combine and match the improvements in different embodiments to make the circuit have multiple advantages. The circuit with multiple improvements in the embodiments is within the scope of the disclosure of the present application and belongs to the protection scope of the present application.

[0142] The present application also proposes a control method of an energy storage device heating circuit for controlling any one of the energy storage device heating circuits mentioned above. The control method of the energy storage device heating circuit can be executed by a controller of the energy storage device heating circuit, which can be realized by updating the function of the controller of the electric drive assembly. In some embodiments, the control method of the energy storage device heating circuit is shown in FIG. 16.

[0143] In step 1601, when the demand for heating the energy storage device arises, step 1602 is triggered to be executed.

[0144] In step 1602, the first switch, the second switch, and the third switch are controlled to be turned on, so that the energy storage device heating circuit is in the heating mode.

[0145] In some embodiments, after the first switch, the second switch and the third switch are controlled to be closed, for example, in the circuit shown in FIG. 1, when in the self-heating state, the first, second and third switches in at least one energy storage group are controlled to be closed. In some embodiments, for example, the first, second and third switches of the first energy storage group are closed, the current flow direction includes: flowing from BT21 to the motor through S21, flowing from the motor to BT11 through S31, realizing the flow of current from BT21 to BT11. In some embodiments, the current flow direction includes: flowing from BT11 to the motor through S31, flowing from the motor to BT21 through S21, realizing the flow of current from BT11 to BT21. In some embodiments, the current flow direction includes: flowing from BT21 to the motor through S21, flowing from the motor to BT11 through S31, flowing from BT11 to the motor through S3, flowing from the motor to BT21 through S21, completing the oscillation of current between BT21 and BT11 through the above-mentioned cycle.

[0146] In the technical solution of the embodiments of the present application, the connection point between the first and second energy storage elements and the motor has a current loop, and in the heating process, the working state of the energy storage device heating circuit can be enriched by using the circuit between the connection point and the motor, an oscillation current is generated between the two groups of energy storage elements, the strength of the oscillation current is improved, and thus the heating speed is improved, which helps to improve the performance of the energy storage device in a low temperature environment; by controlling the switches in each energy storage group, one or more groups of energy storage units can be selectively caused to participate in heating, the flexibility and convenience of heating are improved, and the application scope is also expanded for scenarios with parallel energy storage units.

[0147] In some embodiments, the motor controller of the energy storage device heating circuit includes a bridge arm converter, for example, as shown in FIGS. 1-15. By controlling the on-off state of the switch circuit in the bridge arm converter, the current in the circuit can be repeatedly oscillated between the second energy storage element, the motor and the first energy storage element, realizing the working state of the first to fourth stages in the embodiments shown in FIGS. 4-7 and 9-12. In some embodiments, the first switch circuit is controlled to be turned on and the second switch circuit is controlled to be turned off, so that the energy storage device heating circuit is in the first stage, wherein in the first stage, the second energy storage element charges the motor; the first switch circuit is controlled to be turned off and the second switch circuit is controlled to be turned on, so that the energy storage device heating circuit is in the second stage, wherein in the second stage, the motor discharges the first energy storage element; the first switch circuit is controlled to be turned off and the second switch circuit is controlled to be turned on, so that the energy storage device heating circuit is in the third stage, wherein in the third stage, the first energy storage element charges the motor; the first switch circuit is controlled to be turned on and the second switch circuit is controlled to be turned off, so that the energy storage device heating circuit is in the fourth stage, wherein in the fourth stage, the motor discharges the second energy storage element.

[0148] Through the method, the control current repeatedly oscillates among the second energy storage element, the motor and the first energy storage element, the working state of the energy storage device heating circuit is enriched, the intensity of the oscillation current is improved, and thus the heating speed is improved, which helps to improve the performance of the energy storage device in a low temperature environment.

[0149] In some embodiments, the control method of the energy storage device heating circuit of the application is shown in FIG. 17, and the switches belonging to the same energy storage group are controlled. The control steps in the heating mode include steps 1701-1706.

[0150] In steps 1701-1703, the energy storage device heating circuit is controlled to be in the first state.

[0151] In step 1701, the first switch circuit is controlled to be turned on, and the second switch circuit is controlled to be turned off, so that the energy storage device heating circuit is in the first stage. The current of the second energy storage element reaches the motor control circuit through the second switch, and reaches the motor through the first switch circuit, completing the charging of the second energy storage element to the motor.

[0152] In step 1702, the first switch circuit is controlled to be turned off, and the second switch circuit is controlled to be turned on, so that the energy storage device heating circuit is in the second stage. The current of the motor is charged back to the first energy storage element through the connection point.

[0153] In step 1703, it is judged whether the time length of the circuit in the first state reaches the first time length. If the first time length is reached, step 1704 is executed; if the first time length has not been reached, step 1701 is returned to continue the charging and discharging operation in the first state.

[0154] In steps 1704-1706, the energy storage device heating circuit is controlled to be in the second state.

[0155] In step 1704, the first switch circuit is controlled to be turned off, and the second switch circuit is controlled to be turned on, so that the energy storage device heating circuit is in the third stage. The current flows from the first energy storage element to the motor through the connection point and the third switch, realizing the charging to the motor.

[0156] In step 1705, the first switch circuit is controlled to be turned on, and the second switch circuit is controlled to be turned off, so that the energy storage device heating circuit is in the fourth stage. The current of the motor is charged back to the second energy storage element through the connection point.

[0157] In step 1706, it is judged whether the time length of the circuit in the second state reaches the second time length. If the time length of the circuit in the second state reaches the second time length, step 1701 is executed to switch to the charging and discharging operation in the first state. If the time length of the circuit in the second state has not reached the second time length, step 1704 is returned to continue the charging and discharging operation in the second state.

[0158] In the technical solution of the embodiment, the control of the energy storage device heating circuit to cycle the first and second stages in the first time length and cycle the third and fourth stages in the second time length enables the energy storage device heating circuit to have a current cycle with the first and second time lengths as the cycle length, improves the current intensity in the current oscillation process, and further improves the heating speed, which helps to improve the performance of the energy storage device in a low-temperature environment.

[0159] In some embodiments, the first energy storage element and the second energy storage element of the controlled energy storage device heating circuit have two states of series connection and parallel connection, for example, the positive terminal of the first energy storage element and the positive terminal of the second energy storage element are electrically connected through a fourth switch; the negative terminal of the first energy storage element and the negative terminal of the second energy storage element are electrically connected through a fifth switch; and the positive terminal of the first energy storage element and the negative terminal of the second energy storage element include a sixth switch, wherein the fifth switch is located between the connection point and the negative terminal of the first energy storage element. For the circuit with this connection mode, the fourth switch and the fifth switch can be controlled to be closed, and the third switch and the sixth switch can be controlled to be open, so that the energy storage device heating circuit is in a non-heating mode; the fourth switch and the fifth switch can be controlled to be open, and the third switch and the sixth switch can be controlled to be closed, so that the energy storage device heating circuit is in a heating mode.

[0160] In the technical solution of the embodiment, the state of the energy storage device heating circuit switch is controlled to switch the first energy storage element and the second energy storage element between the parallel connection and the series connection, so that the corresponding switch state can be switched according to the heating requirement, and the convenience of the state control of the energy storage device heating circuit is improved.

[0161] In some embodiments, the controlled energy storage device heating circuit includes two parallel energy storage groups, each of which includes a first energy storage element, a second energy storage element, a second switch, and a third switch; and the energy storage device heating circuit further includes a potential flattening module between the two energy storage groups. For the circuit with this connection feature, the potential flattening module can be controlled to be turned on after the energy storage device heating circuit is controlled to leave the heating mode, so that the potentials of different energy storage units can be balanced, the balance degree of the potentials is improved, and the available time length of the energy storage device heating circuit for performing heating is improved, and the service life of the energy storage device is improved.

[0162] In some embodiments, the controlled energy storage device heating circuit includes at least two parallel energy storage groups, each of which includes a first energy storage element, a second energy storage element, a second switch, and a third switch; the second switch of one energy storage group is the main relay of the electric drive assembly; the energy storage device heating circuit further includes: a pre-charge circuit of the main relay, which is connected in parallel with the main relay; and a seventh switch, which is located between the parallel circuit of the pre-charge circuit and the main relay and the bus end of the motor controller, and is connected between the first bus end of the motor controller and the bus end of the motor controller. For the circuit with this connection feature, the seventh switch and the first switch can be controlled to be closed, and the second switch and the third switch can be controlled to be open, so that the energy storage device heating circuit is in a non-heating mode.

[0163] In the technical solution of the embodiments of the present application, the convenience of switching the energy storage device heating circuit between the heating mode and the non-heating mode can be improved through the control of the switches.

[0164] In some embodiments, the controlled energy storage device heating circuit includes at least three parallel energy storage groups, each of which includes a first energy storage element, a second energy storage element, a second switch, and a third switch; the second switch of one energy storage group is the main relay of the electric drive assembly; the energy storage device heating circuit further includes: a pre-charge circuit of the main relay, which is connected in parallel with the main relay; and a seventh switch, which is located between the parallel circuit of the pre-charge circuit and the main relay and the bus end of the motor controller, and is connected between the first bus end of the motor controller and the bus end of the motor controller. For the circuit with this connection feature, the seventh switch and the first switch can be controlled to be closed, and the second switch and the third switch can be controlled to be open, so that the energy storage device heating circuit is in a non-heating mode.

[0165] In the technical solution of the embodiments of the present application, the convenience of switching the energy storage device heating circuit between the heating mode and the non-heating mode can be improved through the control of the switches.

[0166] The structural diagram of one embodiment of the controller of the present application is shown in Fig. 18. The controller comprises a memory 1801 and a processor 1802. The memory 1801 can be a disk, a flash memory or any other non-volatile storage medium. The memory is used to store the instructions in the corresponding embodiment of the control method for the energy storage device heating circuit described above. The processor 1802 is coupled to the memory 1801 and can be implemented as one or more integrated circuits, such as a microprocessor or a microcontroller. The processor 1802 is used to execute the instructions stored in the memory and can improve the heating efficiency.

[0167] In one embodiment, the controller 1900 can also comprise a memory 1901 and a processor 1902 as shown in Fig. 19. The processor 1902 is coupled to the memory 1901 through a BUS bus 1903. The controller 1900 can also be connected to an external storage device 1905 through a storage interface 1904 to call external data and can be connected to a network or another computer system (not shown) through a network interface 1906. Details are not described here.

[0168] In this embodiment, the data instructions are stored in the memory and processed by the processor, which can improve the heating efficiency.

[0169] The controller of the present application can be part of the controller of the electric drive assembly, which is realized by functional improvement, so that no additional hardware structure is needed, reducing the space occupation and hardware cost.

[0170] In another embodiment, a computer readable storage medium stores computer program instructions, which are executed by a processor to implement the steps of the method in the corresponding embodiment of the control method for the energy storage device heating circuit. Those skilled in the art should understand that the embodiments of the present disclosure can be provided as a method, an apparatus or a computer program product. Therefore, the present disclosure can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present disclosure can be in the form of a computer program product implemented on one or more computer readable non-transitory storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0171] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An energy storage device heating circuit, comprising: a motor controller, a first bus terminal of the motor controller being electrically connected to a negative terminal of a first energy storage element through a first switch, a second bus terminal of the motor controller being electrically connected to a positive terminal of a second energy storage element through a second switch; a motor, a bus terminal of the motor being electrically connected to a connection point through a third switch; and at least two parallel energy storage groups, each of the energy storage groups comprising one of the first energy storage elements, one of the second energy storage elements, one of the second switches, and one of the third switches, wherein a positive terminal of the first energy storage element is electrically connected to the connection point; and a negative terminal of the second energy storage element is electrically connected to the connection point.

2. The energy storage device heating circuit of claim 1, wherein, The first energy storage element comprises at least one energy storage unit group, and the second energy storage element comprises at least one energy storage unit group, each of the energy storage unit groups comprising at least two parallel energy storage units.

3. The energy storage device heating circuit of claim 1 or 2, wherein: a positive terminal of the first energy storage element is electrically connected to a positive terminal of the second energy storage element through a fourth switch; a negative terminal of the first energy storage element is electrically connected to a negative terminal of the second energy storage element through a fifth switch; a positive terminal of the first energy storage element is electrically connected to a negative terminal of the second energy storage element through a sixth switch, wherein the fifth switch is located between the connection point and the negative terminal of the first energy storage element.

4. The energy storage device heating circuit of claim 3, wherein, The energy storage device heating circuit satisfies at least one of: in a non-heating mode, the fourth switch and the fifth switch are closed, and the third switch and the sixth switch are open; or in a heating mode, the fourth switch and the fifth switch are open, and the third switch and the sixth switch are closed.

5. The energy storage device heating circuit of any one of claims 1 to 5, wherein, The second switch of one of the energy storage groups is a main relay of an electric drive assembly.

6. The energy storage device heating circuit of any one of claims 1 to 5, wherein, The number of the energy storage groups is two, and the energy storage device heating circuit further comprises: a potential flattening module located between the two energy storage groups.

7. The energy storage device heating circuit of claim 6, wherein, The potential flattening module comprises at least one switch and at least one resistor.

8. The energy storage device heating circuit of claim 6 or 7, wherein, The potential flattening module comprises a first type of potential flattening module located between the positive terminals of the two second energy storage elements.

9. The energy storage device heating circuit of any one of claims 6-8, wherein, The potential flattening module comprises a second type of potential flattening module located between the connection points belonging to the two energy storage groups.

10. The energy storage device heating circuit of claim 5, further comprising: a pre-charge circuit of a main relay in parallel with the main relay.

11. The energy storage device heating circuit of claim 10, further comprising: a seventh switch located between the pre-charge circuit and the parallel circuit of the main relay close to the bus terminal of the motor controller and the first bus terminal of the motor controller.

12. The energy storage device heating circuit of claim 11, wherein: in a non-heating mode, the seventh switch and the first switch are closed, and the second switch and the third switch are open.

13. The energy storage device heating circuit of any one of claims 6-9, wherein, After the energy storage device heating circuit exits the heating mode, the potential flattening module is turned on.

14. The energy storage device heating circuit of claim 11, wherein, The number of the energy storage groups is greater than 2, and after leaving the heating mode, the energy storage device heating circuit turns on the pre-charge circuit and turns on each energy storage group one by one to the energy storage group where the main relay is located.

15. The energy storage device heating circuit according to claim 1, wherein, The motor controller comprises a bridge arm converter, and the bridge arm converter comprises a plurality of bridge arm branches arranged in parallel, each bridge arm branch comprising a first switch circuit and a second switch circuit connected in series, the first switch circuit being connected to the positive electrode end of the second energy storage element, and the second switch circuit being connected to the negative electrode end of the first energy storage element.

16. The energy storage device heating circuit of claim 15, wherein, For at least one of the energy storage groups, In the first stage, the energy storage device heating circuit, the first switch circuit is turned on, the second switch circuit is turned off, and the second energy storage element charges the motor; In the second stage, the energy storage device heating circuit, the first switch circuit is turned off, the second switch circuit is turned on, and the motor discharges the first energy storage element; In the third stage, the energy storage device heating circuit, the first switch circuit is turned off, the second switch circuit is turned on, and the first energy storage element charges the motor; In the fourth stage, the energy storage device heating circuit, the first switch circuit is turned on, the second switch circuit is turned off, and the motor discharges the second energy storage element.

17. The energy storage device heating circuit of claim 16, wherein, The energy storage device heating circuit alternately stays in the first state and the second state in the heating mode, wherein, In the first state, the energy storage device heating circuit alternately stays in the first stage and the second stage, and the energy storage device heating circuit stays in the first state for a first duration; In the second state, the energy storage device heating circuit alternately stays in the third stage and the fourth stage, and the energy storage device heating circuit stays in the second state for a second duration.

18. The energy storage device heating circuit of any one of claims 1-16, wherein, The energy storage device comprises a battery, the first energy storage element takes a battery pack as an energy storage unit, and the second energy storage element takes the energy storage unit of the battery pack.

19. A control method for an energy storage device heating circuit, wherein, The energy storage device heating circuit comprises a motor controller, a first bus end of the motor controller being connected to the negative electrode end of the first energy storage element through a first switch, a second bus end of the motor controller being connected to the positive electrode end of the second energy storage element through a second switch, a motor, a bus end of the motor being connected to the connection point through a third switch, and at least two parallel energy storage groups, each energy storage group comprising one first energy storage element, one second energy storage element, one second switch, and one third switch, wherein the positive electrode end of the first energy storage element is connected to the connection point, and the negative electrode end of the second energy storage element is connected to the connection point. The control method comprises: For at least one of the energy storage groups, the first switch, the second switch, and the third switch are controlled to be turned on so that the energy storage device heating circuit is in the heating mode.

20. The control method according to claim 19, wherein The motor controller comprises a bridge arm converter, the bridge arm converter comprises a plurality of bridge arm branches arranged in parallel, each bridge arm branch comprises a first switch circuit and a second switch circuit connected in series, the first switch circuit is connected with a positive electrode end of the second energy storage element, and the second switch circuit is connected with a negative electrode end of the first energy storage element; The control method further comprises: for at least one of the energy storage groups, The first switch circuit is controlled to be turned on, and the second switch circuit is controlled to be turned off, so that the heating circuit is in a first stage, wherein in the first stage, the second energy storage element charges the motor; The first switch circuit is controlled to be turned off, and the second switch circuit is controlled to be turned on, so that the heating circuit is in a second stage, wherein in the second stage, the motor discharges the first energy storage element; The first switch circuit is controlled to be turned off, and the second switch circuit is controlled to be turned on, so that the heating circuit is in a third stage, wherein in the third stage, the first energy storage element charges the motor; The first switch circuit is controlled to be turned on, and the second switch circuit is controlled to be turned off, so that the heating circuit is in a fourth stage, wherein in the fourth stage, the motor discharges the second energy storage element.

21. The control method of claim 20, further comprising: controlling the energy storage device heating circuit to alternately be in a first state and a second state, comprising: controlling the energy storage device heating circuit to be in the first state for a first time length; controlling the energy storage device heating circuit to be in the second state for a second time length, wherein the energy storage device heating circuit is in the first state by controlling the energy storage device heating circuit to alternately be in the first stage and the second stage; the energy storage device heating circuit is in the second state by controlling the energy storage device heating circuit to alternately be in the third stage and the fourth stage.

22. The control method according to any one of claims 19 to 21, wherein The positive electrode end of the first energy storage element and the positive electrode end of the second energy storage element are connected through a fourth switch; the negative electrode end of the first energy storage element and the negative electrode end of the second energy storage element are connected through a fifth switch; and a sixth switch is arranged between the positive electrode end of the first energy storage element and the negative electrode end of the second energy storage element, wherein the fifth switch is arranged between the connection point and the negative electrode end of the first energy storage element; The control method further comprises: for at least one of the energy storage groups, The fourth switch and the fifth switch are controlled to be turned on, and the third switch and the sixth switch are controlled to be turned off, so that the energy storage device heating circuit is in a non-heating mode; or The fourth switch and the fifth switch are controlled to be turned off, and the third switch and the sixth switch are controlled to be turned on, so that the energy storage device heating circuit is in a heating mode.

23. The control method according to any one of claims 19 to 21, wherein The number of energy storage groups in the energy storage device heating circuit is 2; The energy storage device heating circuit further comprises a potential flattening module arranged between the two energy storage groups; The control method further comprises: After controlling the energy storage device heating circuit to leave the heating mode, the potential flattening module is controlled to be turned on.

24. The control method according to any one of claims 19 to 22, wherein The second switch of one of the energy storage groups is a main relay of the electric drive assembly; the energy storage device heating circuit further comprises: a pre-charge circuit of the main relay, connected in parallel with the main relay; a seventh switch, located between the parallel circuit of the pre-charge circuit and the main relay and the bus end of the motor controller close to the first bus end of the motor controller; The control method further comprises: controlling the seventh switch and the first switch to be closed, and the second switch and the third switch to be opened, so that the energy storage device heating circuit is in a non-heating mode.

25. The control method according to claim 20 or 21, wherein The energy storage device heating circuit comprises at least three energy storage groups connected in parallel, and the second switch of one of the energy storage groups is a main relay of the electric drive assembly; the energy storage device heating circuit further comprises: a pre-charge circuit of the main relay, connected in parallel with the main relay; a seventh switch, located between the parallel circuit of the pre-charge circuit and the main relay and the bus end of the motor controller close to the first bus end of the motor controller; The control method further comprises: After controlling the energy storage device heating circuit to leave the heating mode, the seventh switch is opened, the pre-charge circuit is controlled to be turned on, and each energy storage group is controlled to be turned on one by one with the energy storage group in which the main relay is located.

26. A controller for an energy storage device heating circuit, comprising: a memory; and a processor coupled to the memory, the processor being configured to perform the method of any one of claims 19 to 25 based on instructions stored in the memory.

27. A non-transitory computer-readable storage medium having computer program instructions stored thereon, the instructions being executed by a processor to implement the method of any one of claims 19 to 25.

28. A computer program product comprising computer programs or instructions, the computer programs or instructions being executed by a processor to implement the method of any one of claims 19 to 25.

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