Battery heating circuit, heating control method, controller, battery system and electric device

Abstract

A battery heating circuit, a heating control method, a controller, a battery system and an electric device. The battery heating circuit comprises: a battery, a resonant capacitor and a bridge arm, wherein the battery has a battery inductor; the resonant capacitor is connected in parallel to the battery, such that the resonant capacitor and the battery inductor form an LC parallel resonant circuit; the bridge arm is connected in parallel to the battery; and the bridge arm comprises a first bridge arm switch tube and a second bridge arm switch tube connected in series.

Description

Battery heating circuit, control method and controller, battery system, and electric device

[0001] Cross Reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202410851934.X, filed on June 27, 2024, and entitled "Battery heating circuit, control method and controller, battery system, and electric device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the electrical field, and more particularly to a battery heating circuit, a control method and a controller, a battery system, and an electric device. BACKGROUND

[0004] At present, a self-heating device is usually arranged on a vehicle, and when the temperature of a battery is too low, the battery of the vehicle is heated by the self-heating device to increase the temperature of the battery. However, the self-heating device in the related art has the problem of high energy consumption. SUMMARY

[0005] The present application is proposed to solve at least one of the above problems. According to a first aspect of the present application, a battery heating circuit is provided, which comprises: a battery, a resonance capacitor, and a bridge arm; wherein the battery has a battery inductance; the resonance capacitor is connected in parallel with the battery to form an LC parallel resonance circuit with the battery inductance; the bridge arm is connected in parallel with the battery; and the bridge arm comprises a first bridge arm switch tube and a second bridge arm switch tube connected in series.

[0006] In an embodiment of the present application, the battery heating circuit further comprises: a current limiting device connected in parallel with the first bridge arm switch tube and connected in series with the second bridge arm switch tube.

[0007] In an embodiment of the present application, the current limiting device comprises at least one of a current limiting resistor, a current limiting inductor, and a current limiting capacitor.

[0008] In an embodiment of the present application, the current limiting device comprises: a current limiting inductor and a current limiting capacitor connected in series.

[0009] In an embodiment of the present application, the battery heating circuit further comprises: a switching device for controlling the conduction and the turn-off between the current limiting device and the bridge arm.

[0010] In an embodiment of the present application, the switching device comprises: a first switch electrically connected between the current limiting device and a bridge arm midpoint of the bridge arm; or / and, a second switch electrically connected between the current limiting device and a bus of the bridge arm; or / and, a third switch, the current limiting device is composed of at least two devices in series, and the third switch is electrically connected between any adjacent two of the devices.

[0011] In an embodiment of the present application, one of the bridge arms in the bridge arm multiplexing inverter, the power factor correction circuit or the DC converter.

[0012] According to the second aspect of the present application, a heating control method is also provided, which is based on any of the above-mentioned battery heating circuits, and the heating control method comprises: controlling the first bridge arm switch tube and the second bridge arm switch tube to alternately turn on and turn off, so as to generate a resonant current in the LC parallel resonant circuit, and heat the battery through the internal resistance of the battery.

[0013] In an embodiment of the present application, the control of the first bridge arm switch tube and the second bridge arm switch tube to alternately turn on and turn off so as to generate a resonant current in the LC parallel resonant circuit comprises: determining a target resonant current; generating a PWM wave control signal according to at least the target resonant current; and controlling the first bridge arm switch tube and the second bridge arm switch tube to alternately turn on and turn off according to the PWM wave control signal, so as to generate the target resonant current in the LC parallel resonant circuit.

[0014] In an embodiment of the present application, the generation of the PWM wave control signal according to at least the target resonant current comprises: determining the frequency and / or the duty cycle of the PWM wave control signal according to at least the target resonant current.

[0015] In an embodiment of the present application, the generation of the PWM wave control signal according to at least the target resonant current comprises: determining the frequency of the PWM wave control signal according to the resonant frequency of the LC parallel resonant circuit; and determining the duty cycle of the PWM wave control signal according to the target resonant current.

[0016] In an embodiment of the present application, the determination of the frequency of the PWM wave control signal according to the resonant frequency of the LC parallel resonant circuit comprises: taking the resonant frequency of the LC parallel resonant circuit as the frequency of the PWM wave control signal.

[0017] In an embodiment of the present application, the battery heating circuit further comprises a current-limiting device and a switching device for controlling the conduction and turn-off between the current-limiting device and the bridge arm; the heating control method further comprises: when the temperature of the battery is lower than a first temperature threshold, controlling the conduction of the current-limiting device and the bridge arm by the switching device, and controlling the bridge arm to generate a resonant current in the LC parallel resonant circuit; when the temperature of the battery is higher than a second temperature threshold, controlling the turn-off of the current-limiting device and the bridge arm by the switching device, and controlling at least one of the first bridge arm switch tube and the second bridge arm switch tube to turn off; wherein the second temperature threshold is greater than the first temperature threshold.

[0018] According to a third aspect of the present application, a controller is further provided, comprising: a storage medium and a processor, the storage medium storing computer instructions run by the processor, the computer instructions, when run by the processor, causing the processor to perform any of the heating control methods described above.

[0019] According to a fourth aspect of the present application, a battery system is further provided, comprising: any of the battery heating circuits described above, or any of the controllers described above.

[0020] According to a fifth aspect of the present application, a power consuming device is further provided, comprising: any of the battery heating circuits described above, any of the controllers described above, or any of the battery systems described above.

[0021] The battery heating circuit, the control method and the controller, the battery system, and the power consuming device provided by the embodiments of the present application adopt a battery inductor, a resonant capacitor, a bridge arm, and a current-limiting device to form a self-heating circuit of the battery, utilize the battery inductor and the resonant capacitor to form an LC parallel resonant circuit, and generate a resonant current in the LC parallel resonant circuit through the first bridge arm switch tube and the second bridge arm switch tube of the bridge arm, so as to heat the battery through the internal resistance of the battery. The impedance of the resonant circuit is small, and the energy consumption is low. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] FIG. 1 is a circuit topology diagram of a battery heating circuit according to an embodiment of the present application;

[0024] Fig. 2 is a circuit topology diagram of a battery heating circuit according to another embodiment of the present application;

[0025] Fig. 3 is a circuit topology diagram of a battery heating circuit according to another embodiment of the present application;

[0026] Fig. 4 is a waveform diagram of output current, resonant current and discharge current of a battery according to an embodiment of the present application;

[0027] Fig. 5 is a flow chart of a heating control method according to an embodiment of the present application;

[0028] Fig. 6 is a schematic block diagram of a controller according to an embodiment of the present application; DETAILED DESCRIPTION

[0029] In order to make the objects, technical solutions and advantages of the present application more obvious, the following will describe the example embodiments according to the present application in detail with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present application.

[0030] In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present application. However, it should be apparent to those skilled in the art that the present application can be practiced without one or more of these details. In other instances, well-known features have not been described in detail in order to avoid obscuring the present application.

[0031] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] At present, the battery self-heating loop is mainly used to realize the self-heating of the battery. For the realization of the self-heating of the battery, the battery is mainly cycled discharged. In related technology I, a bridge arm converter, a winding and an energy storage element are arranged, and the bridge arm converter is used to make the battery and the energy storage element cyclically charge and discharge, so as to heat the battery. In related technology II, a heating loop and an energy storage module are arranged, the heating loop is used to control the battery pack and the energy storage module to cyclically charge and discharge each other, and the alternating current generated makes the internal resistance of the battery pack generate heat. In related technology III, a capacitor unit and a winding inductor assembly are arranged, the winding inductor assembly and the capacitor unit are in a resonant state, and the battery pack is heated. In related technology IV, a motor and a resonant capacitor are used to heat the battery. However, the above-mentioned related technologies require many devices, the charge and discharge circuit of the battery is long, the impedance is large, and the heating efficiency is low. To solve at least part of the above-mentioned problems, the following embodiments are proposed.

[0034] In order to thoroughly understand the present application, detailed structures will be proposed in the following description in order to explain the technical solutions proposed by the present application. The optional embodiments of the present application are described in detail as follows, however, in addition to these detailed descriptions, the present application can have other implementation manners.

[0035] Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] Firstly, the application scenario of the battery heating circuit shown in the present application is introduced, and the battery heating circuit is applied to the self-heating process of the battery.

[0037] Referring to FIG. 1, the battery heating circuit provided by the embodiment of the present application includes a battery 1, a resonant capacitor 2 and a current limiting device 5; wherein the battery 1 has a battery inductance; the resonant capacitor 2 is connected in parallel with the battery 1, so that the resonant capacitor 2 and the battery inductance form an LC parallel resonant circuit; a bridge arm is connected in parallel with the battery 1; the bridge arm includes a first bridge arm switch tube 3 and a second bridge arm switch tube 4 connected in series.

[0038] In the above-mentioned scheme, the battery inductance, the resonant capacitor 2, the bridge arm and the current limiting device 5 form the self-heating loop of the battery 1, the battery inductance and the resonant capacitor 2 form the LC parallel resonant circuit, and the first bridge arm switch tube 3 and the second bridge arm switch tube 4 of the bridge arm generate a resonant current in the LC parallel resonant circuit, so as to heat the battery 1 through the internal resistance of the battery 1. The resonant circuit has few devices, simple structure, small impedance and low energy consumption. The above-mentioned structures will be described in detail below with reference to the accompanying drawings.

[0039] In the setting of the battery 1, any battery device with energy storage function can be adopted. For example, the battery 1 can be a battery on a power consuming device. For example, the power consuming device can be a vehicle, and for example, the battery 1 can be a power battery of the vehicle, and of course, the battery 1 can also be a storage battery of the vehicle. For example, the battery 1 can be composed of a plurality of battery cells in series or parallel. For example, the battery 1 can be a battery pack of the vehicle. Of course, the inductance of the battery 1 is not zero, that is, the battery 1 has a battery inductance, and the battery inductance has the function of inductance, that is, the battery inductance is similar to the equivalent inductance of the battery 1. In application, the inductance of the battery 1 can be measured in advance by measurement, that is, the inductance of the battery inductance is measured by measurement. For example, the battery inductance of the battery 1 itself is L1.

[0040] In the setting of the resonant capacitor 2, any capacitor device can be used as the resonant capacitor 2. For example, the resonant capacitor 2 can be composed of one capacitor unit. For example, the resonant capacitor 2 can also be composed of a plurality of capacitor units in parallel or / and series.

[0041] And the resonant capacitor 2 is connected in parallel with the battery 1, so that the resonant capacitor 2 and the battery inductance form an LC parallel resonance circuit. Specifically, the first end of the resonant capacitor 2 is electrically connected to the positive electrode of the battery 1, and the second end of the resonant capacitor 2 is electrically connected to the negative electrode of the battery 1, so that the resonant capacitor 2 and the battery 1 are connected in parallel to form an LC parallel resonance circuit.

[0042] In the setting of the bridge arm, referring to FIGS. 1-3, the bridge arm includes the first bridge arm switch tube 3 and the second bridge arm switch tube 4 in series, and the bridge arm is connected in parallel with the battery 1. It needs to be explained that the bridge arm refers to a bridge arm circuit formed by two switch tubes in series, one of the two switch tubes is the upper bridge arm switch tube of the bridge arm, and the other is the lower bridge arm switch tube of the bridge arm; correspondingly, the bridge arm has a bridge arm midpoint, which refers to the series node position between the upper bridge arm switch tube and the lower bridge arm switch tube of the bridge arm. The first bridge arm switch tube 3 and the second bridge arm switch tube 4 can be the upper bridge arm switch tube and the lower bridge arm switch tube of the bridge arm, respectively. Referring to FIGS. 1-3, the first bridge arm switch tube 3 is the lower bridge arm switch tube of the bridge arm, and the second bridge arm switch tube 4 is the upper bridge arm switch tube of the bridge arm. Of course, in other embodiments, the first bridge arm switch tube 3 can be the upper bridge arm switch tube of the bridge arm, and the second bridge arm switch tube 4 can be the lower bridge arm switch tube of the bridge arm. In the implementation of connecting the bridge arm in parallel with the battery 1, the positive bus of the bridge arm is electrically connected to the positive electrode of the battery 1, and the negative bus of the bridge arm is electrically connected to the negative electrode of the battery 1, so as to realize the parallel connection between the bridge arm and the battery 1.

[0043] For example, referring to FIGS. 1-3, the first bridge arm switch tube 3 can be electrically connected between the bridge arm midpoint of the bridge arm and the negative bus of the bridge arm, and the second bridge arm switch tube 4 can be electrically connected between the bridge arm midpoint of the bridge arm and the positive bus of the bridge arm. Of course, in other embodiments, the first bridge arm switch tube 3 can be electrically connected between the bridge arm midpoint of the bridge arm and the positive bus of the bridge arm, and the second bridge arm switch tube 4 can be electrically connected between the bridge arm midpoint of the bridge arm and the negative bus of the bridge arm.

[0044] In the above embodiments, the battery inductor, the resonant capacitor 2, the bridge arm, and the current limiting device 5 form a self-heating loop of the battery 1, the battery inductor and the resonant capacitor 2 form an LC parallel resonant circuit, and a resonant current is generated in the LC parallel resonant circuit through the first bridge arm switch tube 3 and the second bridge arm switch tube 4 of the bridge arm to heat the battery 1 through the internal resistance of the battery 1. Compared with the related art, the present application uses the battery inductor of the battery 1 itself as part of the resonant circuit, so that a separate resonant inductor does not need to be provided in the resonant circuit, thereby reducing the number of devices in the resonant circuit, simplifying the structure, reducing the impedance, and reducing the energy consumption.

[0045] In some embodiments, the battery heating circuit can further include a current limiting device 5, the current limiting device 5 is connected in parallel with the first bridge arm switch tube 3, and the current limiting device 5 is connected in series with the second bridge arm switch tube 4. The current limiting device 5 protects the bridge arm switch tube from overloading by limiting the current.

[0046] When the current limiting device 5 is provided, any device with current limiting function can be used to form the current limiting device 5. Referring to FIG. 1, the current limiting device 5 is connected in parallel with the first bridge arm switch tube 3, and the current limiting device 5 is connected in series with the second bridge arm switch tube 4. That is, the current limiting device 5 can be connected in parallel with one of the bridge arm switch tubes on the bridge arm and connected in series with the other bridge arm switch tube on the bridge arm, so as to limit the discharge current on the bridge arm and protect the bridge arm switch tube from overloading. Specifically, the current limiting device 5 is connected in parallel with the first bridge arm switch tube 3 and connected in series with the second bridge arm switch tube 4, so that when the second bridge arm switch tube 4 is turned on, the current limiting device 5 can limit the current flowing through the second bridge arm switch tube 4 to prevent the second bridge arm switch tube 4 from overloading.

[0047] In the specific implementation, the current-limiting device 5 is connected in parallel with the first bridge arm switch tube 3, and the current-limiting device 5 is connected in series with the second bridge arm switch tube 4. Referring to FIG. 1, the first end of the current-limiting device 5 is electrically connected to the bridge arm midpoint of the bridge arm, and the second end of the current-limiting device 5 is electrically connected to the same bus of the bridge arm as the first bridge arm switch tube 3. Referring to FIG. 1, for example, the second end of the current-limiting device 5 can be electrically connected to the negative bus of the bridge arm as the first bridge arm switch tube 3, that is, the first bridge arm switch tube 3 is electrically connected between the bridge arm midpoint of the bridge arm and the negative bus of the bridge arm, and at this time, the second bridge arm switch tube 4 is electrically connected between the bridge arm midpoint of the bridge arm and the positive bus of the bridge arm. Of course, in other embodiments, the second end of the current-limiting device 5 can be electrically connected to the positive bus of the bridge arm as the first bridge arm switch tube 3, that is, the first bridge arm switch tube 3 is electrically connected between the bridge arm midpoint of the bridge arm and the positive bus of the bridge arm, and at this time, the second bridge arm switch tube 4 is electrically connected between the bridge arm midpoint of the bridge arm and the negative bus of the bridge arm.

[0048] In the setting of the current-limiting device 5, various ways can be adopted. For example, referring to FIGS. 2-3, the current-limiting device 5 can include at least one of a current-limiting resistor, a current-limiting inductor 51, and a current-limiting capacitor 52. Specifically, the current-limiting device 5 can include only one of the current-limiting resistor, the current-limiting inductor 51, and the current-limiting capacitor 52, the current-limiting device 5 can include any two of the current-limiting resistor, the current-limiting inductor 51, and the current-limiting capacitor 52, and the current-limiting device 5 can include all of the current-limiting resistor, the current-limiting inductor 51, and the current-limiting capacitor 52. Of course, the number of the current-limiting resistor, the current-limiting inductor 51, and the current-limiting capacitor 52 in the current-limiting device 5 can be one or more.

[0049] For example, referring to FIGS. 2-3, the current-limiting device 5 can include a current-limiting inductor 51 and a current-limiting capacitor 52 connected in series. That is, the current-limiting device 5 at this time includes one current-limiting inductor 51 and one current-limiting capacitor 52, and the current-limiting inductor 51 and the current-limiting capacitor 52 are connected in series. At this time, the first end of the current-limiting inductor 51 can be electrically connected to the bridge arm midpoint of the bridge arm, the second end of the current-limiting inductor 51 can be electrically connected to the first end of the current-limiting capacitor 52, and the second end of the current-limiting capacitor 52 can be electrically connected to the same bus of the bridge arm as the first bridge arm switch tube 3. For example, referring to FIGS. 2 and 3, the second end of the current-limiting capacitor 52 can be electrically connected to the negative bus of the bridge arm as the first bridge arm switch tube 3. By using the current-limiting device 5 composed of the current-limiting inductor 51 and the current-limiting capacitor 52 connected in series, the bridge arm can be prevented from being subjected to a large pulse current at the moment of turn-on or turn-off; and compared with directly using a current-limiting resistor, the heat generated by the current-limiting device 5 can be reduced, thereby reducing the heating power consumption and improving the heating efficiency.

[0050] For example, referring to FIG. 3, the battery heating circuit can further include a switching device for controlling the conduction and non-conduction between the current-limiting device 5 and the bridge arm. That is, by setting the switching device to control the conduction and non-conduction between the current-limiting device 5 and the bridge arm, not only can the battery 1 self-heating function be controlled, but also the bridge arm in other circuits can be reused as the bridge arm in the present embodiment, facilitating the reuse of the bridge arm in the present embodiment and not affecting the bridge arm to achieve different functions at different times.

[0051] When the switching device is set, various setting methods can be used, such as the following exemplary introduction of several setting methods.

[0052] For example, referring to FIG. 3, the switching device can include a first switch 6 electrically connected between the current-limiting device 5 and the bridge arm midpoint of the bridge arm, and the first switch 6 is used to control the conduction and non-conduction between the current-limiting device 5 and the bridge arm midpoint of the bridge arm. Specifically, when the first switch 6 is on, the current-limiting device 5 and the bridge arm midpoint of the bridge arm are on, and when the second end of the current-limiting device 5 and itself are on, the conduction between the current-limiting device 5 and the bridge arm can be achieved. When the first switch 6 is off, the current-limiting device 5 and the bridge arm midpoint of the bridge arm are off, thereby controlling the non-conduction between the current-limiting device 5 and the bridge arm.

[0053] For example, referring to FIG. 3, the switching device can include a second switch 7 electrically connected between the current-limiting device 5 and the bus of the bridge arm, and the second switch 7 is used to control the conduction and non-conduction between the current-limiting device 5 and the bus of the bridge arm. Specifically, when the second switch 7 is on, the current-limiting device 5 and the bus of the bridge arm are on, and when the second end of the current-limiting device 5 and itself are on, the conduction between the current-limiting device 5 and the bridge arm can be achieved. When the second switch 7 is off, the current-limiting device 5 and the bus of the bridge arm are off, thereby controlling the non-conduction between the current-limiting device 5 and the bridge arm. Specifically, as described above, the current-limiting device 5 and the first bridge arm switch tube 3 are electrically connected to the same bus of the bridge arm, and when the first bridge arm switch tube 3 is electrically connected to the negative bus of the bridge arm, the second switch 7 is electrically connected between the current-limiting device 5 and the negative bus of the bridge arm; when the first bridge arm switch tube 3 is electrically connected to the positive bus of the bridge arm, the second switch 7 is electrically connected between the current-limiting device 5 and the positive bus of the bridge arm.

[0054] For example, referring to FIG. 3, the switching device can include a third switch 8, and the current-limiting device 5 is composed of at least two devices in series, and the third switch 8 is electrically connected between any two adjacent devices, that is, the third switch 8 is used to control the conduction and turn-off between the first end and the second end of the current-limiting device 5, so as to control whether the current-limiting device 5 can be conducted with the bridge arm. For example, the current-limiting device 5 includes a current-limiting capacitor 52 and a current-limiting inductor 51 in series, and the third switch 8 can be electrically connected between the current-limiting capacitor 52 and the current-limiting inductor 51, so that when the third switch 8 is turned on, the current-limiting capacitor 52 and the current-limiting inductor 51 are turned on, and when the first end and the second end of the current-limiting device 5 are conducted with the bridge arm midpoint and the bus of the bridge arm respectively, the conduction between the current-limiting device 5 and the bridge arm can be realized. When the third switch 8 is turned off, the current-limiting capacitor 52 and the current-limiting inductor 51 are turned off, so as to realize the turn-off between the current-limiting device 5 and the bridge arm.

[0055] It should be noted that referring to FIG. 3, the first switch 6, the second switch 7 and the third switch 8 in the above embodiment can be only partially provided, or all of them can be provided. Of course, when only part of them is provided, the positions where the switches are not provided are directly electrically connected. When the number of the provided switches is one, the conduction of the one switch can control the conduction of the bridge arm and the current-limiting device 5, and the turn-off of the one switch can control the turn-off of the bridge arm and the current-limiting device 5. When the number of the provided switches is two or three, as long as part of the switches are turned off, the bridge arm and the current-limiting device 5 can be turned off; only when all the switches are turned on, the bridge arm and the current-limiting device 5 can be conducted.

[0056] For example, the above-mentioned bridge arm can reuse one bridge arm in an inverter, a power factor correction circuit or a direct current converter, so as to reduce the cost. For example, the inverter includes three bridge arms in parallel in three phases, and the bridge arm in the embodiment of the application can reuse any one bridge arm in the inverter. It should be noted that the inverter can be used for converting direct current into three-phase current. The inverter can be an inverter on a vehicle, or an inverter on other equipment. It should also be noted that the above-mentioned power factor correction circuit and direct current converter can be devices on a vehicle, or devices on other equipment. The above-mentioned resonant capacitor 2 can be an existing capacitor on the same device, that is, the resonant capacitor 2 can also reuse the capacitor in other circuits, so as to reduce the cost.

[0057] In the various embodiments shown above, the battery inductor, the resonant capacitor 2, the bridge arm and the current-limiting device 5 form a self-heating loop of the battery 1, the LC parallel resonant circuit is formed by the battery inductor and the resonant capacitor 2, and the resonant current is generated in the LC parallel resonant circuit through the first bridge arm switch tube 3 and the second bridge arm switch tube 4 of the bridge arm, so as to heat the battery 1 through the internal resistance of the battery 1. The resonant circuit has few devices, simple structure, small impedance and low energy consumption.

[0058] In addition, the embodiment of the present application further provides a heating control method. Referring to FIGS. 1-3, the heating control method is based on any one of the battery heating circuits described above, and the heating control method comprises the following steps:

[0059] The first bridge arm switch tube 3 and the second bridge arm switch tube 4 are controlled to be turned on and turned off alternately, so as to generate a resonance current in the LC parallel resonance circuit, and the battery 1 is heated through the internal resistance of the battery 1.

[0060] In the above scheme, the battery inductance, the resonance capacitor 2, the bridge arm and the current limiting device 5 are used to form a self-heating circuit of the battery 1. The battery inductance and the resonance capacitor 2 are used to form an LC parallel resonance circuit, and the first bridge arm switch tube 3 and the second bridge arm switch tube 4 of the bridge arm are used to generate a resonance current in the LC parallel resonance circuit, so as to heat the battery 1 through the internal resistance of the battery 1. The required devices are few, the structure is simple, and the difficulty of heating control can be simplified. The above steps will be described in detail below in combination with the accompanying drawings.

[0061] Referring to FIGS. 1-4, the first bridge arm switch tube 3 and the second bridge arm switch tube 4 can be controlled to be turned on and turned off alternately, so as to generate a discontinuous discharge current between the second bridge arm switch tube 4 and the current limiting device 5, and generate a resonance current in the LC parallel resonance circuit formed by the battery inductance and the resonance capacitor 2, so as to heat the battery 1 through the internal resistance of the battery 1. Due to the existence of the current limiting device 5, the value of the discharge current is much smaller than that of the resonance current. However, the duty ratio and / or frequency of the PWM wave control signal of the bridge arm can be controlled to adjust the size of the discharge current, and then adjust the size of the resonance current. That is, the size of the resonance current generated in the LC parallel resonance circuit can be adjusted. For example, referring to FIG. 4, Ibat represents the waveform diagram of the output current of the battery 1, Ic represents the waveform diagram of the resonance current in the LC parallel resonance circuit, and Isub represents the discharge current through the bridge arm. It can be seen that the resonance current is 2-3 times the discharge current. Of course, the proportional relationship between the resonance current and the discharge current can be adjusted according to the requirements and the type of the device.

[0062] The battery self-heating scheme in the related art needs to add a special resonance device between the battery groups, the devices of the resonance circuit are many, the overall impedance of the circuit is large, and the energy consumption is large. The scheme shown in the embodiment of the present application not only needs few devices, but also uses the battery inductance and the resonance capacitor 2 carried in the battery 1 itself to form an LC parallel resonance circuit. The resonance current only flows in the LC parallel resonance circuit, and the discharge current generated on the bridge arm is much smaller than the resonance current, so that the resonance circuit is shorter, the impedance is smaller, the energy consumption is lower, and the heating efficiency is higher compared with the resonance circuit in the related art.

[0063] Exemplarily, the way of controlling the first bridge arm switch tube 3 and the second bridge arm switch tube 4 to alternately turn on and turn off to generate the resonant current in the LC parallel resonant circuit can adopt various ways. Exemplarily, referring to FIG. 5, the way of controlling the first bridge arm switch tube 3 and the second bridge arm switch tube 4 to alternately turn on and turn off to generate the resonant current in the LC parallel resonant circuit can include:

[0064] Step one: determining the target resonant current. As to determining the size of the target resonant current, various ways such as but not limited to the temperature of the battery 1, the ambient temperature where the battery 1 is located, the urgency of heating the battery 1, etc. can be considered. A relatively high target resonant current can be determined, which can improve the heating power and efficiency of the battery 1 under the condition that the internal resistance of the battery 1 remains unchanged, and this embodiment can be applied to the scenario that the temperature of the battery 1 is relatively low, the ambient temperature where the battery 1 is located is relatively low, and the urgency of heating the battery 1 is relatively high. Of course, a relatively low target resonant current can also be determined, which can reduce the heating power and efficiency of the battery 1 under the condition that the internal resistance of the battery 1 remains unchanged, and this embodiment can be applied to the scenario that the temperature of the battery 1 is not particularly low, the ambient temperature where the battery 1 is located is not particularly low, and the urgency of heating the battery 1 is not particularly high.

[0065] Step two: generating the PWM wave control signal according to at least the target resonant current. After determining the target resonant current, the target resonant current needs to be considered when determining the PWM wave control signal, i.e. the target resonant current is used as part or all of the basis for determining the PWM wave control signal.

[0066] Step three: controlling the first bridge arm switch tube and the second bridge arm switch tube to alternately turn on and turn off according to the PWM wave control signal to generate the target resonant current in the LC parallel resonant circuit. After generating the PWM wave control signal, the first bridge arm switch tube 3 and the second bridge arm switch tube 4 can be controlled to alternately turn on and turn off according to the PWM wave control signal to generate the target resonant current in the LC parallel resonant circuit.

[0067] Of course, in other embodiments, the target resonant current can not be determined in advance, but the first bridge arm switch tube 3 and the second bridge arm switch tube 4 can be directly controlled to alternately turn on and turn off, and it can be observed whether the resonant current can be generated in the LC parallel resonant circuit.

[0068] Exemplarily, when generating the PWM wave control signal according to at least the target resonant current, the frequency and / or duty cycle of the PWM wave control signal can be determined according to at least the target resonant current. Specifically, the frequency of the PWM wave control signal can be determined according to the target resonant current, or the duty cycle of the PWM wave control signal can be determined according to the target resonant current. The frequency and duty cycle of the PWM wave control signal can also be determined according to the target resonant current.

[0069] For example, when the PWM wave control signal is generated according to the target resonance current, the frequency of the PWM wave control signal can be determined according to the resonance frequency of the LC parallel resonance circuit, and the duty ratio of the PWM wave control signal can be determined according to the target resonance current. That is, in this embodiment, the frequency of the PWM wave control signal is not determined according to the target resonance current, but only the duty ratio of the PWM wave control signal is determined according to the target resonance current.

[0070] For example, determining the frequency of the PWM wave control signal according to the resonance frequency of the LC parallel resonance circuit can include: taking the resonance frequency of the LC parallel resonance circuit as the frequency of the PWM wave control signal, that is, directly taking the resonance frequency in the LC parallel resonance circuit as the frequency of the PWM wave control signal. Of course, in other embodiments, any value between 1 / 2 and 3 / 2 of the resonance frequency of the LC parallel resonance circuit can be taken as the frequency of the PWM wave control signal.

[0071] For example, as described in the foregoing embodiments, with reference to FIG. 3, the battery heating circuit can further include a current limiting device 5 and a switching device for controlling the conduction and turn-off between the current limiting device 5 and the bridge arm. The heating control method can further include: when the temperature of the battery 1 is lower than a first temperature threshold, controlling the current limiting device 5 and the bridge arm to be conducted by the switching device, and controlling the bridge arm to generate a resonance current in the LC parallel resonance circuit; when the temperature of the battery 1 is higher than a second temperature threshold, controlling the current limiting device 5 and the bridge arm to be turned off by the switching device; and wherein the second temperature threshold is greater than the first temperature threshold.

[0072] Specifically, the temperature of the battery 1 can be periodically acquired, and it can be determined whether the temperature of the battery 1 is lower than a first temperature threshold. The first temperature threshold is preset in advance. For example, the first temperature threshold can be 0°C. When the determination result is that the temperature of the battery 1 is lower than the first temperature threshold, it indicates that the temperature of the battery 1 is too low, and there is a need to heat the battery 1. At this time, the current limiting device 5 and the bridge arm can be first controlled to be conducted by the switching device, and then the bridge arm can be controlled to generate a resonance current in the LC parallel resonance circuit, so as to heat the battery 1 by the internal resistance of the battery 1.

[0073] In the heating process of the battery 1, the temperature of the battery 1 is still periodically acquired, and it is determined whether the temperature of the battery 1 is higher than a second temperature threshold, which is also preset in advance and is greater than the first temperature threshold. For example, the second temperature threshold can be 20°C. When the determination result is that the temperature of the battery 1 is greater than the second temperature threshold, it indicates that the battery 1 has been heated to a relatively high temperature, and the heating of the battery 1 can be stopped. At this time, the current limiting device 5 and the bridge arm can be controlled to be turned off by the switching device, and at least one of the first bridge arm switch tube 3 and the second bridge arm switch tube 4 of the bridge arm can be controlled to be turned off. Specifically, one of the first bridge arm switch tube 3 and the second bridge arm switch tube 4 can be controlled to be turned off, or both of the first bridge arm switch tube 3 and the second bridge arm switch tube 4 can be controlled to be turned off, so as to stop the self-heating of the battery 1.

[0074] And when the bridge arm is the bridge arm in other devices of the multiplex vehicle, during the running of the vehicle, due to the turning off between the current limiting device 5 and the bridge arm controlled by the switching device, and there is no current periodically discharged at the resonant frequency in other circuits, there will be no resonant current between the battery inductance of the battery 1 and the resonant capacitor 2, that is, there will be no resonant current between the battery inductance of the battery 1 and the resonant capacitor 2 in the case that the self-heating function is not started (the switching device controls the current limiting device 5 and the bridge arm to be turned on).

[0075] For example, the resonant capacitor 2 can be determined according to the battery inductance. Specifically, the inductance value L1 of the battery inductance of the battery 1 can be measured, and the capacitance value of the resonant capacitor 2 can be determined as 1 uF (microfarad) corresponding to 1 uH (microhenry).

[0076] For example, the resonant frequency of the LC parallel resonant circuit can also be calculated, and the specific calculation method can use the following formula: f = 1 / [2 * π * (L1 * C1) 1 / 2 ]

[0077] Wherein, f is the resonant frequency of the LC parallel resonant circuit, and C1 is the capacitance value of the resonant capacitor 2.

[0078] For example, a specific heating control method is introduced below taking the battery 1 as the battery on the vehicle.

[0079] S00, measure the inductance of the battery 1 itself, obtain the inductance value L1 of the battery inductance, and obtain the capacitance value of the resonant capacitor 2 according to 1 uH (microhenry) corresponding to 1 uF (microfarad);

[0080] S01, parallel resonant capacitor 2, form a parallel LC parallel resonant circuit between the battery inductance and the resonant capacitor 2, and calculate the resonant frequency of the LC parallel resonant circuit according to the resonance formula;

[0081] S02, parallel the resonant capacitor 2 with the battery 1;

[0082] S03, reuse one bridge arm in the inverter as the bridge arm of the embodiment, specifically, any one of the A-phase bridge arm, B-phase bridge arm, and C-phase bridge arm of the inverter can be reused. The current-limiting inductor 51 and the current-limiting capacitor 52 in parallel as the current-limiting device 5 are connected in parallel with the first bridge arm switch tube 3 (the upper bridge arm switch tube or the lower bridge arm switch tube), and the current-limiting inductor 51 and the current-limiting capacitor 52 are connected in series, for current limiting, as shown in FIG. 2;

[0083] S04, control the reused bridge arm in the inverter to switch the reused bridge arm according to the resonant frequency;

[0084] S05, adjust the duty cycle of the PWM wave control signal of the inverter, so that the resonant current value generated by the LC parallel resonant circuit between the battery 1 and the resonant capacitor 2 is the target resonant current;

[0085] S06, when the parking state, detecting that the battery 1 temperature is lower than the first temperature threshold, such as below 0℃, turn on the current-limiting device 5 branch of the current-limiting inductor 51 and the current-limiting capacitor 52 in series, and send a signal to the controller of the inverter of the vehicle to start the battery self-heating function;

[0086] S07, the controller of the inverter is inherent in the vehicle, after the battery self-heating function is started, the controller controls the inverter to periodically discharge through the current-limiting inductor 51 and the current-limiting capacitor 52 at the resonant frequency;

[0087] S08, the LC parallel resonant circuit is composed of the battery 1 and the resonant capacitor 2, the resonant capacitor 2 can be newly added or replaced with the existing one in the driving assembly, the resonant current flows through the battery 1, and the battery 1 is heated through the internal resistance of the battery 1;

[0088] S09, when detecting that the battery 1 temperature rises to the second temperature threshold, the switching device on the current-limiting inductor 51 and the current-limiting capacitor 52 can be turned off, and a signal to close the self-heating function is sent to the controller of the inverter;

[0089] S10, when the bridge arm is reused in the bridge arm of other devices in the vehicle, during the operation of the vehicle, since the switching device controls the current-limiting device 5 and the bridge arm to be off, and there is no current with the resonant frequency periodically discharged in other circuits, the resonant current will not be formed between the battery inductance of the battery 1 and the resonant capacitor 2, that is, there will be no resonant current between the battery inductance of the battery 1 and the resonant capacitor 2 when the self-heating function is not started (the switching device controls the current-limiting device 5 and the bridge arm to be on).

[0090] In the various embodiments shown above, a self-heating circuit of the battery 1 is formed by the battery inductance, the resonant capacitor 2, the bridge arm and the current limiting device 5. An LC parallel resonant circuit is formed by the battery inductance and the resonant capacitor 2, and a resonant current is generated in the LC parallel resonant circuit through the first bridge arm switch tube 3 and the second bridge arm switch tube 4 of the bridge arm, so as to heat the battery 1 through the internal resistance of the battery 1. Compared with the related art, the resonant circuit of the present application has fewer devices, a simple structure, small impedance and low energy consumption, and can simplify the difficulty of heating control.

[0091] The battery self-heating scheme in the related art needs to add a special resonant device between the battery groups, the resonant circuit has many devices, the overall impedance of the circuit is large, and the energy consumption is large. The scheme shown in the embodiments of the present application not only has fewer required devices, but also uses the battery inductance and the resonant capacitor 2 carried in the battery 1 itself to form an LC parallel resonant circuit. The resonant current only flows in the LC parallel resonant circuit, and the discharge current generated on the bridge arm is much smaller than the resonant current. Therefore, compared with the resonant circuit in the related art, the resonant circuit in the present application has a shorter length, small impedance, low energy consumption and the advantage of high heating efficiency.

[0092] In some embodiments, compared with the related battery self-heating scheme, in some embodiments of the present application, a resonant capacitor 2 is connected in parallel with the battery 1, and one bridge arm in the multiplexed inverter is used as the bridge arm in the embodiments of the present application. The first bridge arm switch tube 3 (which can be an upper bridge arm switch tube or a lower bridge arm switch tube) is connected in parallel with the current limiting device 5. The bridge arm controls the current limiting device 5 to periodically store energy in the battery inductance in the battery 1, and forms a resonant current in the LC parallel resonant circuit between the battery inductance and the resonant capacitor 2 in the battery 1 itself. The discharge current on the bridge arm switch tube of the bridge arm is much smaller than the resonant current and is discontinuous, so as to reduce the energy consumption of the bridge arm switch tube and reduce the heat generation of the bridge arm. In some embodiments, the duty ratio and / or frequency of the PWM wave control signal for controlling the bridge arm can be adjusted to adjust the discharge current, and then the size of the resonant current can be adjusted.

[0093] Compared with the above-mentioned related art, in the scheme of the embodiments of the present application, the resonant circuit flows through fewer devices (only through the battery 1 and the resonant capacitor 2), has small impedance, low energy consumption, requires less energy for the same battery temperature rise, and has high heating efficiency. In some embodiments, the bridge arm is multiplexed with a bridge arm in the inverter, such as but not limited to, which saves cost. The discharge circuit is connected in parallel with the first bridge arm switch tube 3 by the current limiting device 5, and does not need other devices to participate. The parameter setting is flexible, and the resonant current in the LC parallel resonant circuit can be conveniently controlled by software.

[0094] For example, compared with the related art one, the current limiting device 5 in the application can be connected in parallel with the upper bridge arm switch tube of the bridge arm, or connected in parallel with the lower bridge arm switch tube of the bridge arm, and the current limiting device 5 (the current limiting capacitor 52 and the current limiting inductor 51) connected in parallel is used for limiting discharge. The resonant current in the embodiment of the application is between the battery inductance in the battery 1 and the resonant capacitor 2, and some embodiments reuse the bridge arm of the inverter to save cost. The related art one is to control a new-attached bridge arm by connecting the inductor capacitor in parallel with the lower bridge arm switch tube of the new-attached bridge arm, to form a self-heating current between the inductor capacitor connected in parallel with the lower bridge arm switch tube and the battery 1. It can be seen that the resonant current loops of the two are different, and the functions of the inductor capacitor connected in parallel with the bridge arm are different.

[0095] Compared with the related art two, the application connects a resonant capacitor 2 in parallel with the battery 1, and forms an LC parallel resonant loop by using the battery inductance of the battery 1 to heat the battery 1. The related art two is to set an energy storage device, and charge and discharge between the energy storage device and the battery pack. It can be seen that the heating loops of the two are different.

[0096] Compared with the related art three, the current limiting device 5 in the application can be connected in parallel with the upper bridge arm switch tube of the bridge arm, or connected in parallel with the lower bridge arm switch tube of the bridge arm, and the current limiting device 5 (the current limiting capacitor 52 and the current limiting inductor 51) connected in parallel is used for limiting discharge. The resonant current in the embodiment of the application is between the battery inductance in the battery 1 and the resonant capacitor 2, and some embodiments reuse the bridge arm of the inverter to save cost. The related art three is to externally connect a winding inductor and a capacitor, and the resonant self-heating circuit is between the battery 1, the winding inductor and the capacitor. It can be seen that the resonant loops of the two are different.

[0097] Compared with the related art four, the scheme in the embodiment of the application does not need to involve the motor, and the motor itself does not heat, and the heating loops of the two are different.

[0098] Furthermore, the embodiment of the application further provides a controller. Referring to FIG. 6, the controller 100 includes a storage medium 110 and a processor 120, the storage medium 110 stores a computer program which is run by the processor 120, and the computer program, when being run by the processor 120, causes the processor 120 to execute any one of the heating control methods described above. For example, the controller 100 can be a controller of an inverter of a vehicle, a vehicle controller, a controller of a battery management system, etc.

[0099] FIG. 6 shows a schematic block diagram of the controller 100 according to an embodiment of the present application. As shown in FIG. 6, the controller 100 according to an embodiment of the present application can include a storage medium 110 and a processor 120, the storage medium 110 storing computer instructions run by the processor 120, the computer instructions, when run by the processor 120, causing the processor 120 to perform the heating control method according to an embodiment of the present application as previously described. Those skilled in the art can understand the specific operation of the controller 100 according to an embodiment of the present application to deploy the device in combination with the foregoing content, and for brevity, will not be described here.

[0100] The storage medium 110 may, for example, include a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium can be any combination of one or more computer-readable storage media.

[0101] Further, the present application also provides a battery system, referring to FIGS. 1-6, the battery system includes any of the battery heating circuits or any of the controllers. For example, the battery system can be a battery system of a vehicle, in which case the battery in the battery system can be a power battery or a storage battery of the vehicle. For example, the battery system can also be a battery system of an energy storage station, in which case the battery in the battery system can be an energy storage battery of the energy storage station.

[0102] Further, the present application also provides a battery system, referring to FIGS. 1-6, the battery system includes any of the battery heating circuits or any of the controllers. For example, the battery system can be a battery system of a vehicle, in which case the battery in the battery system can be a power battery or a storage battery of the vehicle. For example, the battery system can also be a battery system of an energy storage station, in which case the battery in the battery system can be an energy storage battery of the energy storage station.

[0103] The present application has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and illustration, and are not intended to limit the present application to the scope of the described embodiments. Furthermore, those skilled in the art can understand that the present application is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present application, which all fall within the scope of the present application claimed. The scope of protection of the present application is defined by the attached claims and their equivalent scope.

Claims

1. A battery heating circuit, characterized in that, include: Battery (1) has battery inductance; A resonant capacitor (2) is connected in parallel with the battery (1) so that the resonant capacitor (2) and the battery inductance form an LC parallel resonant circuit; and The bridge arm is connected in parallel with the battery (1); the bridge arm includes a first bridge arm switch tube (3) and a second bridge arm switch tube (4) connected in series.

2. The battery heating circuit as described in claim 1, characterized in that, Also includes: The current limiting device (5) is connected in parallel with the first bridge arm switch (3) and in series with the second bridge arm switch (4).

3. The battery heating circuit as described in claim 2, characterized in that, The current limiting device (5) includes at least one of a current limiting resistor, a current limiting inductor (51), and a current limiting capacitor (52).

4. The battery heating circuit as described in claim 2 or 3, characterized in that, The current limiting device (5) includes a current limiting inductor (51) and a current limiting capacitor (52) connected in series.

5. The battery heating circuit as described in claim 2, characterized in that, Also includes: A switching device is used to control the conduction and cutoff between the current limiting device (5) and the bridge arm.

6. The battery heating circuit as described in claim 5, characterized in that, The switching device includes: A first switch (6) is electrically connected between the current limiting device (5) and the midpoint of the bridge arm; or / and, The second switch (7) is electrically connected between the current limiting device (5) and the busbar of the bridge arm; or / and, The third switch (8) is composed of at least two devices connected in series, and the third switch (8) is electrically connected between any two adjacent devices.

7. The battery heating circuit as described in claim 1, characterized in that, The bridge arm is a multiplexed inverter, a power factor correction circuit, or a DC-DC converter.

8. A heating control method, characterized in that, The heating control method is based on the battery heating circuit according to any one of claims 1 to 7, and the heating control method includes: The first bridge arm switch (3) and the second bridge arm switch (4) are controlled to alternately turn on and off, generating a resonant current in the LC parallel resonant circuit to heat the battery (1) through the internal resistance of the battery (1).

9. The heating control method as described in claim 8, characterized in that, The method of controlling the first bridge arm switch (3) and the second bridge arm switch (4) to alternately turn on and off to generate a resonant current in the LC parallel resonant circuit includes: Determine the target resonant current; At least based on the target resonant current, a PWM wave control signal is generated; According to the PWM wave control signal, the first bridge arm switch (3) and the second bridge arm switch (4) are controlled to alternately turn on and off, so as to generate the target resonant current in the LC parallel resonant circuit.

10. The heating control method as described in claim 9, characterized in that, The step of generating a PWM wave control signal based at least on the target resonant current includes: The frequency and / or duty cycle of the PWM wave control signal are determined based at least on the target resonant current.

11. The heating control method as described in claim 10, characterized in that, The step of generating a PWM wave control signal based at least on the target resonant current includes: The frequency of the PWM wave control signal is determined based on the resonant frequency of the LC parallel resonant circuit. The duty cycle of the PWM wave control signal is determined based on the target resonant current.

12. The heating control method as described in claim 11, characterized in that, Determining the frequency of the PWM wave control signal based on the resonant frequency of the LC parallel resonant circuit includes: The resonant frequency of the LC parallel resonant circuit is used as the frequency of the PWM wave control signal.

13. The heating control method according to any one of claims 8 to 12, characterized in that, The battery heating circuit further includes a current limiting device (5) and a switching device, wherein the switching device is used to control the conduction and cutoff between the current limiting device (5) and the bridge arm; The heating control method further includes: When the temperature of the battery (1) is lower than the first temperature threshold, the current limiting device (5) is controlled to conduct with the bridge arm by the switching device, and the bridge arm is controlled to generate a resonant current in the LC parallel resonant circuit; When the temperature of the battery (1) is higher than the second temperature threshold, the current limiting device (5) and the bridge arm are turned off by the switching device, and at least one of the first bridge arm switching tube (3) and the second bridge arm switching tube (4) is turned off; wherein the second temperature threshold is greater than the first temperature threshold.

14. A controller, characterized in that, include: A storage medium and a processor, wherein the storage medium stores computer instructions that are executed by the processor, the computer instructions, when executed by the processor, cause the processor to perform the heating control method as described in any one of claims 8 to 13.

15. A battery system, characterized in that, include: The battery heating circuit as described in any one of claims 1 to 7, or the controller as described in claim 14.

16. An electrical appliance, characterized in that, include: The battery heating circuit as described in any one of claims 1 to 7, the controller as described in claim 14, or the battery system as described in claim 15.

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