Battery heating circuit and unmanned vehicle

Abstract

The invention discloses a battery heating circuit and an unmanned vehicle. The battery heating circuit comprises a first battery pack and a second battery pack which are connected in parallel; the inverter comprises at least two upper bridge arms and at least two lower bridge arms, the first ends of the upper bridge arms are connected with the positive electrodes of the first battery pack and the second battery pack, the second ends of the upper bridge arms are connected with the first ends of the lower bridge arms, and the second ends of the lower bridge arms are connected with the negative electrodes of the first battery pack and the second battery pack; the inverter is used for inverting direct current into alternating current; the first end of the motor is connected with the second end of each upper bridge arm, and the second end of the motor is connected with the anode of the first battery pack; the control module is connected with the inverter and used for controlling the upper bridge arm to be switched on and the lower bridge arm to be switched off so that the first battery pack and the second battery pack can be heated or the motor can store energy. Or the lower bridge arm is controlled to be switched on and the upper bridge arm is controlled to be switched off, so that the first battery pack is heated or the motor stores energy. According to the invention, the battery heating effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery heating, and in particular to a battery heating circuit and an unmanned vehicle. Background Art

[0002] As the most important energy supply component of unmanned vehicles, batteries have a direct impact on the performance of the entire vehicle. When the battery is in a low temperature environment, the activity of the positive and negative electrode materials and the electrolyte of the battery will decrease, affecting its charging and discharging performance, and thus affecting the performance of the entire vehicle. Therefore, when the battery is in a low temperature environment, it is necessary to heat the battery to increase its temperature, thereby ensuring the normal use of the power and charging performance of the unmanned vehicle in cold conditions.

[0003] However, most of the existing technologies use a heating film arranged inside the battery for heating. However, the heating film has a large heat loss during the heating process, has a low heating efficiency and a large power consumption, and has a poor heating effect. Summary of the invention

[0004] The invention provides a battery heating circuit and an unmanned vehicle to improve the heating effect of the battery.

[0005] According to one aspect of the present invention, there is provided a battery heating circuit, comprising:

[0006] a first battery group and a second battery group, wherein the first battery group and the second battery group are connected in parallel;

[0007] An inverter, comprising at least two upper bridge arms and at least two lower bridge arms, wherein a first end of the upper bridge arm is connected to a positive electrode of the first battery group and the second battery group, a second end of the upper bridge arm is connected to a first end of the lower bridge arm, and a second end of the lower bridge arm is connected to a negative electrode of the first battery group and the second battery group; the inverter is used to invert direct current output by the first battery group or the second battery group into alternating current;

[0008] A motor, wherein the first end of the motor is connected to the second end of each of the upper bridge arms respectively, and the first end of the motor is arranged in a one-to-one correspondence with the second end of the upper bridge arm, and the second end of the motor is connected to the positive electrode of the first battery pack;

[0009] A control module is connected to the inverter and is used to control the upper bridge arm to be turned on and the lower bridge arm to be turned off so that the first battery group is heated, the second battery group is heated, or the motor stores energy; or to control the lower bridge arm to be turned on and the upper bridge arm to be turned off so that the first battery group is heated or the motor stores energy.

[0010] Optionally, the control module is used to:

[0011] In a first time sequence, the lower bridge arm is controlled to be turned on and the upper bridge arm is controlled to be turned off; a current flows out of the positive electrode of the first battery pack, and a current loop is formed through the motor, the lower bridge arm and the negative electrode of the first battery pack;

[0012] The first battery pack supplies power to the motor so that the motor stores energy.

[0013] Optionally, the control module is further used for:

[0014] In the second time sequence, the upper bridge arm is controlled to be turned on and the lower bridge arm is turned off; the positive electrode of the first battery pack flows out current, and a current loop is formed through the motor, the upper bridge arm, the second battery pack and the negative electrode of the first battery pack;

[0015] The first battery pack and the motor jointly supply power to the second battery pack to heat the second battery pack.

[0016] Optionally, the control module is further used for:

[0017] In a third time sequence, the upper bridge arm is controlled to remain turned on and the lower bridge arm is controlled to remain turned off; a current flows out of the positive electrode of the second battery pack, and a current loop is formed through the upper bridge arm, the motor, the first battery pack and the negative electrode of the second battery pack;

[0018] The second battery pack supplies power to the motor and the first battery pack, so that the first battery pack is heated and the motor stores energy.

[0019] Optionally, the control module is further used for:

[0020] In a fourth time sequence, the lower bridge arm is controlled to be turned on and the upper bridge arm is controlled to be turned off; a current flows out of the second end of the motor, and a current loop is formed through the first battery pack, the lower bridge arm and the first end of the motor;

[0021] The motor supplies power to the first battery pack to heat the first battery pack.

[0022] Optionally, the inverter includes: a three-phase bridge arm connected between the positive electrode and the negative electrode of the second battery group; each phase bridge arm of the three-phase bridge arm includes an upper bridge arm and a lower bridge arm.

[0023] Optionally, the motor includes: a three-phase winding, wherein the windings in the three-phase winding are arranged in a one-to-one correspondence with the bridge arms in the three-phase bridge arms, the first end of the three-phase winding includes three connecting parts, the three connecting parts are respectively connected to the three bridge arms in the three-phase bridge arms in a one-to-one correspondence, and each of the connecting parts is connected to the second end of the upper bridge arm, and the second end of the three-phase winding is connected to the positive pole of the first battery pack.

[0024] Optionally, the battery heating circuit further includes:

[0025] A first switch module, the first switch module is connected between the positive electrode of the first battery pack and the positive electrode of the second battery pack, the first switch module is also connected to the control module, and the control module is used to control the first switch module to be turned on or off;

[0026] The second switch module is connected between the positive pole of the first battery pack and the second end of the motor. The second switch module is also connected to the control module. The control module is used to control the second switch module to be turned on or off.

[0027] Optionally, the battery heating circuit further includes:

[0028] A bus capacitor is connected in parallel with the second battery group.

[0029] According to another aspect of the present invention, there is provided an unmanned vehicle, comprising: the battery heating circuit described in any embodiment of the present invention.

[0030] The technical solution provided by the embodiment of the present invention connects the first battery group and the motor, and the control module can control the upper bridge arm and the lower bridge arm in the inverter to be turned on and off in a time-sharing manner, and the DC power is inverted into AC power and input into the first battery group or the second battery group, thereby realizing the heating of the first battery group or the second battery group. By dividing the battery into a first battery group and a second battery group connected in parallel, the cyclic heating of the first battery group and the second battery group is realized, and the heating amount is relatively balanced. And when one of the battery groups is heated, the heated battery group can maintain normal power supply, and has high reliability. The present invention does not need to add a new heating film, has a higher heating efficiency and a lower power consumption, and has a better heating effect.

[0031] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1is a structural schematic diagram of a battery heating circuit provided according to an embodiment of the present invention;

[0034] Figure 2 is a structural schematic diagram of another battery heating circuit provided according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram of current flow of a battery heating circuit within a first time sequence provided by an embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of current flow of a battery heating circuit within a second time sequence provided by an embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of current flow of a battery heating circuit within a third time sequence provided by an embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of current flow of a battery heating circuit within a fourth time sequence provided by an embodiment of the present invention;

[0039] Figure 7 It is a schematic diagram of the structure of an unmanned vehicle provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] An embodiment of the present invention provides a battery heating circuit. Figure 1A schematic diagram of a battery heating circuit provided by an embodiment of the present invention. Figure 1 The battery heating circuit includes: a first battery group 1, a second battery group 2, an inverter 3, a motor 4 and a control module 5. The first battery group 1 and the second battery group 2 are connected in parallel. The inverter 3 includes at least two upper bridge arms 31 and at least two lower bridge arms 32, the first end of the upper bridge arm 31 is connected to the positive pole of the first battery group 1 and the second battery group 2, the second end of the upper bridge arm 31 is connected to the first end of the lower bridge arm 32, and the second end of the lower bridge arm 32 is connected to the negative pole of the first battery group 31 and the second battery group 32; the inverter 3 is used to invert the direct current output by the first battery group 31 or the second battery group 32 into alternating current. The motor 4 is connected to the second end of each upper bridge arm 31, and the motor 4 is arranged one by one with the second end of the upper bridge arm 31, and the motor 4 is also connected to the positive pole of the first battery group 1. The control module 5 is connected to the inverter 3, and is used to control the upper bridge arm 31 to be turned on and the lower bridge arm 32 to be turned off, so that the first battery group 1 is heated, the second battery group 2 is heated, or the motor 4 stores energy; or control the lower bridge arm 32 to be turned on and the upper bridge arm 31 to be turned off, so that the first battery group 1 is heated or the motor 4 stores energy.

[0043] Among them, when the battery is at low temperature, for example, below -10℃ to -20℃, the internal resistance of the battery will increase several times relative to normal temperature, and the activity of the electrolyte will also decrease. At this time, the battery is divided into a first battery group 1 and a second battery group 2 connected in parallel, and the control module 5 can heat the first battery group 1 or the second battery group 2 by time-sharing control of the on and off of the upper bridge arm 31 or the lower bridge arm 32 of the inverter 3. When heating one battery group, the heated battery group can still maintain normal power supply. This setting will not cause the entire battery to lose power due to the battery being in a heated state.

[0044] Specifically, when the control module 5 controls the upper bridge arm 31 to be turned off and the lower bridge arm 32 to be turned on, the first battery pack 1 discharges and supplies power to the motor 4, and the motor 4 can store energy through its internal inductive load.

[0045] When the motor 4 completes energy storage, the control module 5 controls the upper bridge arm 31 to turn on and the lower bridge arm 32 to turn off. Because the inductive load has the characteristics of inductance, the current direction of the motor 4 remains unchanged. At this time, the first battery group 1 and the motor 4 are discharged together and input into the inverter 3. The inverter 3 can invert the direct current output by the first battery group 1 into alternating current. Exemplarily, the alternating current can be a high-frequency sinusoidal current. When the second battery group 2 receives the alternating current, the current direction of the alternating current will change periodically, causing the polarity of the power source of the alternating current connected to the second battery group 2 to change continuously. For example, when the alternating current is input to the positive pole of the second battery group 2, the polarity of the alternating current input to the positive pole of the second battery group 2 will continuously switch between the positive pole and the negative pole. When the positive pole of the second battery group 2 receives the negative polarity alternating current, the second battery group 2 will form a short-circuit condition, thereby heating the second battery group 2. Because the frequency of the alternating current is high, the duration of the short-circuit condition is short, and the second battery group 2 will not generate too much heat to cause damage to itself.

[0046] When the motor 4 discharges all the stored electric energy, the second battery pack 2 starts to discharge, and the DC power output by the second battery pack 2 is inverted into AC power through the inverter 3. The AC power supplies power to the motor 4 through the upper bridge arm 31, and the output current of the motor 4 is reversed, and the AC power is transmitted to the first battery pack 1 while storing energy. When the first battery pack 1 receives the AC power, it will cause the first battery pack 1 to form a short-circuit condition in a very short time, thereby heating the first battery pack 1.

[0047] When the motor 4 completes energy storage, the control module 5 controls the upper bridge arm 31 to turn off and the lower bridge arm 32 to turn on, and the motor 4 inputs the stored electric energy into the first battery pack 1. Exemplarily, the motor 4 may include a three-phase winding, which may be used to store energy or output alternating current. The alternating current output by the motor 4 through the three-phase winding heats the first battery pack.

[0048] By continuously and cyclically controlling the turning off or on of the upper bridge arm 31 and the turning off or on of the lower bridge arm 32, the first battery group 1 and the second battery group 2 can be heated cyclically. When the first battery group 1 or the second battery group 2 is in the heating state, it can also supply power to other electrical devices in the circuit at the same time.

[0049] The technical solution provided by the embodiment of the present invention connects the first battery group 1 and the motor 4, and the control module 5 can control the upper bridge arm 31 and the lower bridge arm 32 in the inverter 3 to be turned on and off in a time-sharing manner, and the DC power is inverted into AC power and input into the first battery group 1 or the second battery group 2, thereby realizing the heating of the first battery group 1 or the second battery group 2. By dividing the battery into the first battery group 1 and the second battery group 2 connected in parallel, the cyclic heating of the first battery group 1 and the second battery group 2 is realized, and the heating amount is relatively balanced. And when one of the battery groups is heated, the heated battery group can maintain normal power supply, and has high reliability. The present invention does not need to add a new heating film, has a higher heating efficiency and a lower power consumption, and has a better heating effect.

[0050] Figure 2 This is a schematic diagram of another battery heating circuit provided by an embodiment of the present invention. Figure 2 On the basis of the above embodiments, optionally, the inverter 3 includes: a three-phase bridge arm connected between the positive electrode and the negative electrode of the second battery group 2; each phase bridge arm in the three-phase bridge arm includes an upper bridge arm 31 and a lower bridge arm 32.

[0051] Among them, two IGBTs (Insulated Gate Bipolar Transistor) can be set in each phase bridge arm of the inverter 3, which are respectively set in the upper bridge arm 31 and the lower bridge arm 32. The control module can control the on-off of the upper bridge arm 31 and the lower bridge arm 32 by controlling the on-off of the IGBT.

[0052] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the motor 4 includes: a three-phase winding, the windings in the three-phase winding are arranged in a one-to-one correspondence with the bridge arms in the three-phase bridge arms, the first end of the three-phase winding includes three connecting parts, the three connecting parts are respectively connected to the three bridge arms in the three-phase bridge arms in a one-to-one correspondence, and each connecting part is connected to the second end of the upper bridge arm 31, and the second end of the three-phase winding is connected to the positive pole of the first battery group 1.

[0053] Among them, the three-phase winding of the motor 4 has the characteristics of inductance, which can store energy and generate voltage. The low-efficiency square wave emitted by the first battery group 1 or the second battery group 2 can be inverted into a high-frequency sinusoidal current with high efficiency for inductive loads through the three-phase bridge arm and the three-phase winding. When the high-frequency sinusoidal current is input into the battery, the internal molecules of the electrolyte in the battery can vibrate and rub at high speed to generate heat. Due to the rapid change in the direction of the high-frequency sinusoidal current, the polarity of the power supply will also change continuously at high speed, causing the battery to form a short-circuit condition in a very short time, thereby increasing the heat generation.

[0054] Continue to refer Figure 2On the basis of the above embodiments, optionally, the battery heating circuit further includes: a first switch module 6 and a second switch module 7. The first switch module 6 is connected between the positive electrode of the first battery pack 1 and the positive electrode of the second battery pack 2, and the first switch module 6 is also connected to the control module, and the control module is used to control the first switch module 6 to be turned on or off. The second switch module 7 is connected between the positive electrode of the first battery pack 1 and the second end of the motor 4, and the second switch module is also connected to the control module, and the control module is used to control the second switch module 7 to be turned on or off.

[0055] Among them, when the battery temperature is normal, the second switch module 7 is in a disconnected state, and the three-phase winding of the motor 4 is not directly connected to the first battery pack 1. After the first switch module 6 is turned on, the motor 4 is powered by the first battery pack 1 and the second battery pack 2. When the battery temperature is low, the second switch module 7 can be turned on and the first switch module 6 can be disconnected. At this time, the cyclic heating of the first battery pack 1 and the second battery pack 2 can be achieved by controlling the conduction or disconnection of the upper bridge arm 31 or the lower bridge arm 32. Exemplarily, the first switch module 6 and the second switch module 7 may include: a relay.

[0056] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the battery heating circuit further includes: a bus capacitor C1 connected in parallel with the second battery pack 2. The bus capacitor C1 can be used for energy storage, filtering or voltage stabilization.

[0057] Figure 3 A schematic diagram of current flow in a battery heating circuit within a first time sequence provided by an embodiment of the present invention. Figure 3 On the basis of the above embodiments, the control module is optionally used to: in the first time sequence, control the lower bridge arm 32 to be turned on and the upper bridge arm 31 to be turned off; the positive electrode of the first battery pack 1 flows out current, and forms a current loop through the motor 4, the lower bridge arm 32 and the negative electrode of the first battery pack 1. The first battery pack 1 supplies power to the motor 4 so that the motor 4 stores energy.

[0058] Among them, by dividing the first timing, the second timing, the third timing and the fourth timing, and making the battery heating circuit cyclically execute these four timings in sequence, cyclic heating between the first battery group 1 and the second battery group 2 can be achieved.

[0059] Specifically, the arrows in the diagram can be used to indicate the direction of current flow. In the first time sequence, the control module controls the lower bridge arm 32 to turn on and controls the upper bridge arm 31 to turn off, the positive pole of the first battery group 1 outputs electrical energy, and the current flows into the lower bridge arm 32 through the motor 4, and flows back to the negative pole of the first battery group 1 through the lower bridge arm 32. At this time, the electric energy output by the first battery group 1 can power the three-phase winding in the motor 4 and store energy through the three-phase winding. Exemplarily, the three lower bridge arms 32 can evenly divide the output current of the first battery group 1 so that the conduction currents of the three lower bridge arms 32 are equal.

[0060] In the first time sequence, the first battery group 1 and the second battery group 2 are not heated, and the second battery group 2 can supply power to other high-voltage components connected to the first battery group 1 .

[0061] Figure 4 A schematic diagram of the current flow of a battery heating circuit in a second time sequence provided by an embodiment of the present invention. Figure 4 On the basis of the above embodiments, optionally, the control module is further used to: in the second time sequence, control the upper bridge arm 31 to be turned on and the lower bridge arm 32 to be turned off; the positive electrode of the first battery group 1 flows out current, and forms a current loop through the motor 4, the upper bridge arm 31, the second battery group 2 and the negative electrode of the first battery group 1. The first battery group 1 and the motor 4 jointly supply power to the second battery group 2, so that the second battery group 2 is heated.

[0062] Among them, in the second time sequence, the control module controls the upper bridge arm 31 to be turned on and controls the lower bridge arm 32 to be turned off, the positive electrode of the first battery group 1 outputs electric energy, the current flows into the upper bridge arm 31 through the motor 4, and flows into the positive electrode of the second battery group 2 through the upper bridge arm 31, and flows back to the negative electrode of the first battery group 1 from the negative electrode of the second battery group 2. At this time, the current direction of the three-phase winding in the motor 4 remains unchanged, the three-phase windings in the first battery group 1 and the motor 4 discharge together, and the upper bridge arm 31 and the three-phase winding invert the electric energy into alternating current and input it into the positive electrode of the second battery group 2. Exemplarily, the alternating current can be a high-frequency sinusoidal current. By inputting the alternating current into the second battery group 2, the internal molecules of the electrolyte of the battery in the second battery group 2 can be made to oscillate and heat up by friction at a high speed, and the alternating current polarity of the positive electrode of the second battery group 2 will also continuously switch between the positive electrode and the negative electrode. When the positive electrode of the second battery group 2 receives the alternating current of negative polarity, the second battery group 2 will form a short-circuit condition, thereby achieving the heating of the second battery group 2.

[0063] Figure 5 A schematic diagram of the current flow of a battery heating circuit in a third time sequence provided by an embodiment of the present invention. Figure 5On the basis of the above embodiments, optionally, the control module is further used to: in the third time sequence, control the upper bridge arm 31 to remain on and the lower bridge arm 32 to remain off; the positive electrode of the second battery group 2 flows out current, and forms a current loop through the upper bridge arm 31, the motor 4, the first battery group 1 and the negative electrode of the second battery group 2. The second battery group 2 supplies power to the motor 4 and the first battery group 1, so that the first battery group 1 is heated and the motor 4 stores energy.

[0064] Among them, in the second timing, the three-phase winding in the motor 4 continues to discharge, and when the second timing ends and is about to enter the third timing, the electric energy stored in the three-phase winding in the motor 4 is completely released. When entering the third timing, the upper bridge arm 31 remains in the on state in the second timing, and the lower bridge arm 32 remains in the off state in the second timing. At this time, the second battery pack 2 switches from the charging state to the discharging state, the positive electrode of the second battery pack 2 outputs electric energy, the current flows into the motor 4 through the upper bridge arm 31, and flows from the motor 4 into the positive electrode of the first battery pack 1, and the current flows back to the negative electrode of the second battery pack 2 through the negative electrode of the first battery pack 1. The first battery pack 1 begins to heat up, and at the same time, the three-phase winding in the motor 4 stores energy.

[0065] Figure 6 A schematic diagram of the current flow of a battery heating circuit in a fourth time sequence provided by an embodiment of the present invention. Figure 6 On the basis of the above embodiments, optionally, the control module is further used to: in the fourth time sequence, control the lower bridge arm 32 to be turned on and the upper bridge arm 31 to be turned off; the second end of the motor 4 flows out current and forms a current loop through the first battery pack 1, the lower bridge arm 32 and the first end of the motor 4. The motor 4 supplies power to the first battery pack 1 so that the first battery pack 1 is heated.

[0066] Among them, in the fourth time sequence, the control module controls the lower bridge arm 32 to be turned on and controls the upper bridge arm 31 to be turned off, the three-phase winding in the motor 4 outputs electric energy, and the current passes through the positive electrode of the first battery group 1, and flows from the negative electrode of the first battery group 1 into the lower bridge arm 32 and then flows back to the three-phase winding. In this time sequence, the three-phase winding supplies power to the first battery group 1 so that the first battery group 1 is heated.

[0067] After the fourth timing, the first timing can continue to be executed, and in the order of the first timing, the second timing, the third timing and the fourth timing, the upper bridge arm 31 and the lower bridge arm 32 are controlled to perform corresponding on or off, and the first battery group 1 or the second battery group 2 is heated through different current flow cycles of the battery heating circuit.

[0068] The embodiment of the present invention further provides an unmanned vehicle. The unmanned vehicle comprises: the battery heating circuit provided by any embodiment of the present invention has similar beneficial effects as the battery heating circuit, which will not be described in detail here.

[0069] Figure 7 A schematic diagram of the structure of an unmanned vehicle provided by an embodiment of the present invention. Figure 7 The unmanned vehicle may include a slow start module 11, a battery management module 12, a slow charging rectifier module 13, an integrated fast and slow charging socket 14, multiple loads 15 and a voltage sampling module 16.

[0070] Among them, the slow start module 11 is connected in series between the positive electrode of the second battery pack 2 and the first end of the upper bridge arm 31. When the first battery pack 1 and the second battery pack 2 are supplying power to the motor 4, the first switch K1 is closed first, and the current of the first battery pack 1 and the second battery pack 2 is input into the bus capacitor C1 through the first resistor R1, thereby avoiding damage to the bus capacitor C1 due to excessive current input when the unmanned vehicle is started. After the bus capacitor C1 has been charged for a certain period of time, the first switch K1 is disconnected, the second switch K2 is closed, and the first battery pack 1 and the second battery pack 2 directly supply power to the bus capacitor C1.

[0071] The first end of the battery management module 12 is connected to the negative electrode of the first battery group 1 and the second battery group 2, and the second end of the battery management module 12 is connected to the second end of the lower bridge arm 32 through the first fuse F1. The battery management module 12 is used to manage and protect the first battery group 1 and the second battery group 2.

[0072] The fast and slow charging integrated socket 14 and the slow charging rectifier module 13 are both connected in parallel to the second battery group 2, and the fast and slow charging integrated socket 14 is also connected to the slow charging rectifier module 13. When the fast and slow charging integrated socket 14 is connected to high-voltage direct current, the fast and slow charging integrated socket 14 can directly input the high-voltage direct current into the first battery group 1 and the second battery group 2. When the fast and slow charging integrated socket 14 is connected to low-voltage alternating current, the slow charging rectifier module 13 can rectify the alternating current into direct current and input it into the first battery group 1 and the second battery group 2. A third switch K3 can be provided between the fast and slow charging integrated socket 14 and the positive pole of the first battery group 1, which can be used to cut off the input of high-voltage direct current. A fourth fuse F4 can be provided between the slow charging rectifier module 13 and the positive pole of the first battery group 1, which can be used to limit the output current of the slow charging rectifier module 13.

[0073] The first battery pack 1 and the second battery pack 2 may also be connected in parallel with a plurality of loads 15, and the current may be limited by the second fuse F2. For example, the load 15 may be a compressor, a sweeper, or other electrical equipment in an unmanned vehicle. For example, when the second battery pack 2 is heated, the second battery pack 2 may maintain power supply to the load 15.

[0074] The voltage sampling module 16 is connected in parallel with the inverter 3 and can be used to sample the voltage of the inverter 3. The voltage sampling module 16 is also connected to the control module. The control module determines the working state of the inverter 3 according to the sampled voltage of the voltage sampling module 16, thereby realizing safety protection of the inverter 3.

[0075] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0076] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery heating circuit, characterized in that: include: a first battery group and a second battery group, wherein the first battery group and the second battery group are connected in parallel; An inverter, comprising at least two upper bridge arms and at least two lower bridge arms, wherein a first end of the upper bridge arm is connected to a positive electrode of the first battery group and the second battery group, a second end of the upper bridge arm is connected to a first end of the lower bridge arm, and a second end of the lower bridge arm is connected to a negative electrode of the first battery group and the second battery group; the inverter is used to invert direct current output by the first battery group or the second battery group into alternating current; A motor, wherein the first end of the motor is connected to the second end of each of the upper bridge arms respectively, and the first end of the motor is arranged in a one-to-one correspondence with the second end of the upper bridge arm, and the second end of the motor is connected to the positive electrode of the first battery pack; A control module is connected to the inverter and is used to control the upper bridge arm to be turned on and the lower bridge arm to be turned off so that the first battery group is heated, the second battery group is heated, or the motor stores energy; or to control the lower bridge arm to be turned on and the upper bridge arm to be turned off so that the first battery group is heated or the motor stores energy.

2. The battery heating circuit according to claim 1, characterized in that: The control module is used for: In a first time sequence, the lower bridge arm is controlled to be turned on and the upper bridge arm is controlled to be turned off; a current flows out of the positive electrode of the first battery pack, and a current loop is formed through the motor, the lower bridge arm and the negative electrode of the first battery pack; The first battery pack supplies power to the motor so that the motor stores energy.

3. The battery heating circuit according to claim 1, characterized in that: The control module is also used for: In the second time sequence, the upper bridge arm is controlled to be turned on and the lower bridge arm is turned off; the positive electrode of the first battery pack flows out current, and a current loop is formed through the motor, the upper bridge arm, the second battery pack and the negative electrode of the first battery pack; The first battery pack and the motor jointly supply power to the second battery pack to heat the second battery pack.

4. The battery heating circuit according to claim 1, characterized in that: The control module is also used for: In a third time sequence, the upper bridge arm is controlled to remain turned on and the lower bridge arm is controlled to remain turned off; a current flows out of the positive electrode of the second battery pack, and a current loop is formed through the upper bridge arm, the motor, the first battery pack and the negative electrode of the second battery pack; The second battery pack supplies power to the motor and the first battery pack, so that the first battery pack is heated and the motor stores energy.

5. The battery heating circuit according to claim 1, characterized in that: The control module is also used for: In a fourth time sequence, the lower bridge arm is controlled to be turned on and the upper bridge arm is controlled to be turned off; a current flows out of the second end of the motor, and a current loop is formed through the first battery pack, the lower bridge arm and the first end of the motor; The motor supplies power to the first battery pack to heat the first battery pack.

6. The battery heating circuit according to claim 1, characterized in that: The inverter comprises: a three-phase bridge arm connected between the positive electrode and the negative electrode of the second battery group; each phase bridge arm of the three-phase bridge arm comprises an upper bridge arm and a lower bridge arm.

7. The battery heating circuit according to claim 6, characterized in that: The motor includes: a three-phase winding, wherein the windings in the three-phase winding are arranged in a one-to-one correspondence with the bridge arms in the three-phase bridge arms, and the first end of the three-phase winding includes three connecting parts, and the three connecting parts are respectively connected to the three bridge arms in the three-phase bridge arms in a one-to-one correspondence, and each of the connecting parts is connected to the second end of the upper bridge arm, and the second end of the three-phase winding is connected to the positive pole of the first battery pack.

8. The battery heating circuit according to claim 1, characterized in that: The battery heating circuit also includes: A first switch module, the first switch module is connected between the positive electrode of the first battery pack and the positive electrode of the second battery pack, the first switch module is also connected to the control module, and the control module is used to control the first switch module to be turned on or off; The second switch module is connected between the positive pole of the first battery pack and the second end of the motor. The second switch module is also connected to the control module. The control module is used to control the second switch module to be turned on or off.

9. The battery heating circuit according to claim 1, characterized in that: The battery heating circuit also includes: A bus capacitor is connected in parallel with the second battery group.

10. An unmanned vehicle, characterized in that: include: The battery heating circuit according to any one of claims 1 to 9.

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