Heating device

Abstract

The utility model discloses a heating device, and relates to the technical field of new energy, the heating device comprises a first number of heating circuits and a first number of switch tube driving circuits, and the switch tube driving circuits are in one-to-one correspondence with the heating circuits; each heating circuit is connected in parallel with the power battery; the heating circuit comprises a second number of switch tubes; the switching tube driving circuit comprises a second number of driving branches; the driving branches are in one-to-one correspondence with the switching tubes, and the signal output ends of the driving branches are connected with the control ends of the corresponding switching tubes. The heating device can reduce electrical cost and installation space.

Description

Technical Field

[0001] This application relates to the field of new energy technology, and in particular to a heating device. Background Technology

[0002] Electric vehicles are powered by batteries, which are significantly affected by low temperatures. For example, when the temperature drops below 0°C, the usable capacity of a lithium battery may decrease to 50%-70% of that at room temperature. This results in a significant reduction in the driving range of electric vehicles, impacting the user experience. The charging speed of lithium batteries also slows down at low temperatures, and charging at extremely low temperatures may damage battery life. For instance, at -20°C, the charging speed of a lithium-ion battery may only be about one-third of that at room temperature. To ensure proper charging and the long-term health of the battery, it is necessary to heat the battery.

[0003] Currently, commonly used battery heating solutions include: 1. Liquid thermal heating, which utilizes the circulation of a heating liquid (such as an aqueous solution of ethylene glycol) within the battery thermal management system to transfer heat to the battery through a heat exchanger. 2. Electric heating film heating. 3. Heat pump heating. However, the above solutions suffer from drawbacks such as high cost and large size. Therefore, how to overcome these technical shortcomings has become a pressing technical problem for those skilled in the art. Utility Model Content

[0004] The purpose of this application is to provide a heating device that can reduce electrical costs and installation space.

[0005] To solve the above-mentioned technical problems, this application provides a heating device, comprising:

[0006] A first number of heating circuits and a first number of switching transistor drive circuits, each corresponding to one of the heating circuits; each heating circuit is connected in parallel with a power battery; each heating circuit includes a second number of switching transistors; each switching transistor drive circuit includes a second number of drive branches; each drive branch corresponds to one of the switching transistors, and the signal output terminal of each drive branch is connected to the control terminal of the corresponding switching transistor.

[0007] In some embodiments, the drive branch includes:

[0008] A drive power supply circuit and a switching transistor isolation driver are provided. The control terminal of the drive power supply circuit is connected to a controller, the power output terminal of the drive power supply circuit is connected to the switching transistor isolation driver, the control terminal of the switching transistor isolation driver is connected to the controller, and the output terminal of the switching transistor isolation driver serves as the signal output terminal of the drive branch and is connected to the control terminal of the corresponding switching transistor in the drive branch.

[0009] In some embodiments, the drive power supply circuit includes:

[0010] First switching transistor, transformer and rectifier circuit;

[0011] The first terminal of the first switching transistor is connected to the controller, the second terminal of the first switching transistor is grounded, the third terminal of the first switching transistor is connected to one end of the primary winding of the transformer, the other end of the primary winding of the transformer is connected to the auxiliary power supply, the two ends of the secondary winding of the transformer are connected to the rectifier circuit, and the output terminal of the rectifier circuit serves as the output terminal of the drive power supply circuit.

[0012] In some embodiments, the rectifier circuit includes:

[0013] First diode and second diode;

[0014] The anode of the first diode is connected to one end of the secondary winding of the transformer, and the cathode of the first diode serves as the first output terminal of the drive power supply circuit. The cathode of the second diode is connected to the other end of the secondary winding of the transformer, and the anode of the second diode serves as the second output terminal of the drive power supply circuit.

[0015] In some embodiments, the drive power supply circuit further includes:

[0016] A filter circuit; the filter circuit is connected to the output terminal of the rectifier circuit.

[0017] In some embodiments, the filtering circuit includes:

[0018] First capacitor and second capacitor;

[0019] One end of the first capacitor is connected to the cathode of the first diode, the other end of the first capacitor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the anode of the second diode.

[0020] In some embodiments, the heating device includes a first heating circuit, a second heating circuit, and a third heating circuit; the first heating circuit, the second heating circuit, and the third heating circuit are connected in parallel with the power battery.

[0021] In some embodiments, the first heating circuit includes: a second switching transistor and a third switching transistor;

[0022] The first end of the second switch is connected to the signal output terminal of the corresponding drive branch, the second end of the second switch is connected to the third end of the third switch, the third end of the second switch is connected to one end of the power battery, the first end of the third switch is connected to the signal output terminal of the corresponding drive branch, and the second end of the third switch is connected to the other end of the power battery.

[0023] In some embodiments, the second heating circuit includes: a fourth switching transistor and a fifth switching transistor;

[0024] The first end of the fourth switch is connected to the signal output terminal of the corresponding drive branch, the second end of the fourth switch is connected to the third end of the fifth switch, the third end of the fourth switch is connected to one end of the power battery, the first end of the fifth switch is connected to the signal output terminal of the corresponding drive branch, and the second end of the fifth switch is connected to the other end of the power battery.

[0025] In some embodiments, the third heating circuit includes: a sixth switching transistor and a seventh switching transistor;

[0026] The first end of the sixth switch is connected to the signal output terminal of the corresponding drive branch, the second end of the sixth switch is connected to the third end of the seventh switch, the third end of the sixth switch is connected to one end of the power battery, the first end of the seventh switch is connected to the signal output terminal of the corresponding drive branch, and the second end of the seventh switch is connected to the other end of the power battery.

[0027] The heating device provided in this application includes: a first number of heating circuits and a first number of switching transistor drive circuits, wherein each switching transistor drive circuit corresponds to one of the heating circuits; each heating circuit is connected in parallel with a power battery; each heating circuit includes a second number of switching transistors; each switching transistor drive circuit includes a second number of drive branches; each drive branch corresponds to one of the switching transistors, and the signal output terminal of each drive branch is connected to the control terminal of the corresponding switching transistor.

[0028] As can be seen, the heating device provided in this application includes several heating circuits and a switching transistor drive circuit. The heating circuit includes several switching transistors, and the switching transistor drive circuit includes several drive branches, each of which is responsible for driving a corresponding switching transistor. When the drive branch drives the switching transistor to not be fully turned on, the switching transistor itself generates heat, and the coolant can carry away the heat generated by these switching transistors to heat the battery. In this way, the heat generated by the switching transistor when it is not fully turned on can heat the battery without the need for a heat pump or other equipment. Compared with existing heating solutions such as heat pump heating, this application can reduce electrical costs and installation space, which is beneficial for reducing the weight of electric vehicles. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of a heating device provided in an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of a driving branch provided in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of a drive power supply circuit provided in an embodiment of this application;

[0033] Figure 4 A schematic diagram of a specific heating circuit provided in an embodiment of this application;

[0034] Figure 5 A schematic diagram of another specific heating circuit provided in an embodiment of this application;

[0035] Figure 6 A schematic diagram of a specific drive branch provided in an embodiment of this application;

[0036] Figure 7 This is a schematic diagram of another specific drive branch provided in an embodiment of this application. Detailed Implementation

[0037] The core of this application is to provide a heating device that can reduce electrical costs and installation space.

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a heating device provided in an embodiment of this application, with reference to... Figure 1 As shown, the device includes:

[0040] A first number of heating circuits 10 and a first number of switching transistor drive circuits 20, wherein each switching transistor drive circuit 20 corresponds to one of the heating circuits 10; each heating circuit 10 is connected in parallel with a power battery; each heating circuit 10 includes a second number of switching transistors 101; each switching transistor drive circuit 20 includes a second number of drive branches 201; each drive branch 201 corresponds to one of the switching transistors 101, and the signal output terminal of each drive branch 201 is connected to the control terminal of the corresponding switching transistor 101.

[0041] The heating circuit 10 includes a second number of switching transistors 101, and the switching transistor driving circuit 20 includes a second number of driving branches 201. Each switching transistor 101 has a corresponding driving branch 201, and the driving branch 201 is responsible for driving the corresponding switching transistor 101.

[0042] The number of heating circuits 10 and the number of switching transistors in the heating circuits 10 can be determined according to the heating capacity requirements of the heating device. If it is necessary for the heating circuits 10 to generate more heat, more heating circuits 10 and more switching transistors in the heating circuits 10 can be provided.

[0043] When the heating circuit 10 is also used to drive the motor, the number of heating circuits 10 and the number of switching transistors in each heating circuit 10 can be determined according to the driving method of the motor. If the motor is driven by three-phase AC power, the number of heating circuits 10 can be 3, and the number of switching transistors in each heating circuit 10 can be 2. The 3 heating circuits 10 and the 2 switching transistors in each heating circuit 10 constitute a three-phase inverter circuit, which can invert the DC power from the power battery into three-phase AC power to drive the motor.

[0044] refer to Figure 2 As shown, in some embodiments, the drive branch 201 includes:

[0045] A drive power supply circuit and a switching transistor isolation driver are provided. The control terminal of the drive power supply circuit is connected to the controller, the power output terminal of the drive power supply circuit is connected to the switching transistor isolation driver, the control terminal of the switching transistor isolation driver is connected to the controller, and the output terminal of the switching transistor isolation driver serves as the signal output terminal of the drive branch 201 and is connected to the control terminal of the corresponding switching transistor 101 of the drive branch 201.

[0046] The drive power supply circuit outputs drive power to the switching transistor isolation driver, which in turn drives the switching transistor 101. The controller outputs a PWM signal to the drive power supply circuit, thereby controlling the magnitude of the voltage output by the drive power supply circuit. Different output voltages from the drive power supply circuit result in different amplitudes of the signal output from the switching transistor isolation driver to the control terminal of switching transistor 101. The controller can output a PWM signal to the switching transistor isolation driver to control the width of the signal output by the switching transistor isolation driver. This allows for controllable voltage control at the control terminal of switching transistor 101.

[0047] refer to Figure 3 As shown, in some embodiments, the drive power supply circuit includes:

[0048] First switching transistor Q1, transformer TX and rectifier circuit;

[0049] The first terminal of the first switch Q1 is connected to the controller, the second terminal of the first switch Q1 is grounded, the third terminal of the first switch Q1 is connected to one end of the primary winding of the transformer TX, the other end of the primary winding of the transformer TX is connected to the auxiliary power supply, the two ends of the secondary winding of the transformer TX are connected to the rectifier circuit, and the output terminal of the rectifier circuit serves as the output terminal of the drive power supply circuit.

[0050] When the first switch Q1 is turned on, current flows through the primary winding of transformer TX. Conversely, when the first switch Q1 is turned off, no current flows through the primary winding of transformer TX. The AC power output from the secondary winding of transformer TX is rectified into DC power by the rectifier circuit. The voltage output by the drive power supply circuit can be controlled by controlling the conduction frequency of the first switch Q1.

[0051] The first switching transistor Q1 can specifically be an IGBT. The first terminal of the first switching transistor Q1 is the gate of the IGBT, the second terminal of the first switching transistor Q1 is the emitter of the IGBT, and the third terminal of the first switching transistor Q1 is the collector of the IGBT. It is clear that, besides using an IGBT, the first switching transistor Q1 can also be a MOSFET.

[0052] The drive power supply circuit provided in this embodiment has a simple circuit structure, which can reduce the electrical cost and installation space of the drive power supply circuit.

[0053] In some embodiments, the rectifier circuit includes:

[0054] First diode D1 and second diode D2;

[0055] The anode of the first diode D1 is connected to one end of the secondary winding of the transformer TX, and the cathode of the first diode D1 serves as the first output terminal of the drive power supply circuit. The cathode of the second diode D2 is connected to the other end of the secondary winding of the transformer TX, and the anode of the second diode D2 serves as the second output terminal of the drive power supply circuit.

[0056] In this embodiment, the rectifier circuit includes two diodes, which rectify the AC power output from the secondary winding of the transformer TX into DC power. The rectifier circuit provided in this embodiment has a simple structure, which can reduce the electrical cost and installation space of the drive power supply circuit.

[0057] In some embodiments, the drive power supply circuit further includes:

[0058] A filter circuit; the filter circuit is connected to the output terminal of the rectifier circuit.

[0059] In this embodiment, the drive power supply circuit also includes a filter circuit. By filtering the DC power output from the rectifier circuit, the stability and reliability of the DC power output from the drive power supply circuit can be improved.

[0060] In some embodiments, the filtering circuit includes:

[0061] First capacitor C1 and second capacitor C2;

[0062] One end of the first capacitor C1 is connected to the cathode of the first diode, the other end of the first capacitor C1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the anode of the second diode.

[0063] In this embodiment, the filter circuit includes two capacitors, which filter the DC output from the rectifier circuit. The filter circuit provided in this embodiment has a simple structure, which can reduce the electrical cost and installation space of the drive power supply circuit.

[0064] In some embodiments, the heating device includes a first heating circuit, a second heating circuit, and a third heating circuit; the first heating circuit, the second heating circuit, and the third heating circuit are connected in parallel with the power battery.

[0065] refer to Figure 4 As shown, the heating device includes three heating circuits 10, each of which is connected in parallel with the power battery.

[0066] refer to Figure 5 As shown, in some embodiments, the first heating circuit includes: a second switch Q2 and a third switch Q3; the first end of the second switch Q2 is connected to the signal output terminal of the corresponding drive branch 201, the second end of the second switch Q2 is connected to the third end of the third switch Q3, the third end of the second switch Q2 is connected to one end of the power battery, the first end of the third switch Q3 is connected to the signal output terminal of the corresponding drive branch 201, and the second end of the third switch Q3 is connected to the other end of the power battery.

[0067] The second heating circuit includes a fourth switch Q4 and a fifth switch Q5; the first end of the fourth switch Q4 is connected to the signal output terminal of the corresponding drive branch 201, the second end of the fourth switch Q4 is connected to the third end of the fifth switch Q5, the third end of the fourth switch Q4 is connected to one end of the power battery, the first end of the fifth switch Q5 is connected to the signal output terminal of the corresponding drive branch 201, and the second end of the fifth switch Q5 is connected to the other end of the power battery.

[0068] The third heating circuit includes a sixth switch Q6 and a seventh switch Q7; the first end of the sixth switch Q6 is connected to the signal output terminal of the corresponding drive branch 201, the second end of the sixth switch Q6 is connected to the third end of the seventh switch Q7, the third end of the sixth switch Q6 is connected to one end of the power battery, the first end of the seventh switch Q7 is connected to the signal output terminal of the corresponding drive branch 201, and the second end of the seventh switch Q7 is connected to the other end of the power battery.

[0069] The second switch Q2 to the seventh switch Q7 can be specifically IGBT transistors. The first terminal of the second switch Q2 to the seventh switch Q7 is the gate of the IGBT transistor, the second terminal of the second switch Q2 to the seventh switch Q7 is the emitter of the IGBT transistor, and the second terminal of the second switch Q2 to the seventh switch Q7 is the collector of the IGBT transistor.

[0070] When an IGBT is operating normally, it turns on when the voltage Vgs between its gate and emitter reaches the turn-on threshold voltage (typically 3-6V, varying depending on the model). When Vgs falls below the turn-on threshold voltage, the IGBT cannot fully conduct; it remains in a partially conducting state. In this partially conducting state, the IGBT's on-resistance is significantly higher than when fully conducting. According to the formula P=I^2*R (where P is power loss, I is current, and R is resistance), the increased on-resistance leads to substantial power loss as current flows. This power loss is dissipated as heat, causing the IGBT to overheat. Therefore, when heating is required, the IGBT's drive voltage should be kept below or near the turn-on threshold voltage, thus keeping the IGBT in a partially conducting state, increasing power loss and heat generation.

[0071] It is clear that, in addition to using IGBT transistors, the second to seventh switching transistors Q2 can also be MOSFETs.

[0072] The heating circuit provided in this embodiment can also be used to drive a motor.

[0073] Specifically, the end of the second switch Q2 connected to the third switch Q3 can be connected to the U-phase input terminal of the motor. The end of the fourth switch Q4 connected to the fifth switch Q5 can be connected to the V-phase input terminal of the motor. The end of the sixth switch Q6 connected to the seventh switch Q7 can be connected to the W-phase input terminal of the motor.

[0074] The end of the second switch Q2 connected to the third switch Q3 is also connected to the U-phase input terminal of the motor; the end of the fourth switch Q4 connected to the fifth switch Q5 is also connected to the V-phase input terminal of the motor; and the end of the sixth switch Q6 connected to the seventh switch Q7 is also connected to the W-phase input terminal of the motor. At this time, the motor can still be driven through the second switch Q2 to the seventh switch Q7.

[0075] When the vehicle is in motion, the Vgs of the IGBT can be controlled to make the IGBT operate in a partially conducting state. This results in greater power loss and increased heat generation from the IGBT, which is then carried away by the coolant to heat the battery. Controlling the IGBT to a smaller pulse at this time ensures reliability, allowing the vehicle to travel at low speeds.

[0076] When the vehicle is stationary, the Vgs of the IGBT is controlled to make the IGBT work in a partially conductive state. The controller adjusts the control scheme so that the IGBT becomes a heat load and generates heat, which is then carried away by the coolant to heat the battery.

[0077] For example, taking the heating of the second switch Q2 and the third switch Q3 as an example, combined with Figure 6 and Figure 7 As shown, Figure 6 and Figure 7 In this context, PWM-PWCT is the signal used to control the drive power supply circuit. Figure 6 In the above, PWM-DR-A is the signal controlling the isolation driver of the switching transistor in the drive branch 201 corresponding to the second switching transistor Q2, and DRV_A is the signal controlling the second switching transistor Q2. Figure 7 In the above, PWM-DR-B is the signal controlling the isolation driver of the switch in the drive branch 201 corresponding to the third switch Q3, and DRV_B is the signal controlling the third switch Q3.

[0078] When the vehicle requires driving, the controller adjusts the amplitude or frequency of the PWM-PWCT signal, thereby regulating the amplitude of the voltage output by the isolation driver of the switching transistor, achieving controllable drive voltage. When heating is required, the Vgs of the second switching transistor Q2 is lowered or near the turn-on threshold voltage, placing Q2 in a partially turned-on state, similar to being in the linear amplification region (for a MOSFET). This increases the power loss and heat generation of Q2. Simultaneously, the PWM-DR-A signal is controlled to maintain a relatively small duty cycle, relying on the heat generated by the second switching transistor Q2 to heat the coolant, and thus the battery.

[0079] When the vehicle needs to move, the controller adjusts the amplitude or frequency of the PWM-PWCT signal, thereby regulating the voltage amplitude output by the isolation driver of the switching transistors and achieving controllable drive voltage. When heating is required, the Vgs of the second switching transistor Q2 is kept below or near the conduction threshold voltage, placing Q2 in a partially conducting state. Due to the higher impedance of Q2, its power loss and heat generation increase. Simultaneously, the PWM-DR-A signal is controlled identically, ensuring a small duty cycle. This effectively makes the second and third switching transistors Q2 and Q3 act as loads, preventing current from flowing into the motor and ensuring the vehicle remains completely stationary and safe. The heat generated by the second switching transistor Q2 heats the coolant, which in turn heats the battery.

[0080] Similarly, when the vehicle needs to drive, the controller adjusts the amplitude or frequency of the PWM-PWCT signal, thereby adjusting the amplitude of the voltage output by the isolation driver of the switching transistor, achieving controllable drive voltage. When heating is required, the Vgs of the third switching transistor Q3 is lowered or close to the turn-on threshold voltage, placing Q3 in a partially turned-on state, similar to being in the linear amplification region (for a MOSFET). This increases the power loss and heat generation of Q3. Simultaneously, the PWM-DR-A signal is controlled to maintain a relatively small duty cycle, relying on the heat generated by the third switching transistor Q3 to heat the coolant, and thus the battery.

[0081] When the vehicle needs to move, the controller adjusts the amplitude or frequency of the PWM-PWCT signal, thereby regulating the voltage amplitude output by the isolation driver of the switching transistors and achieving controllable drive voltage. When heating is required, the Vgs of the third switching transistor Q3 is kept below or near the conduction threshold voltage, placing Q3 in a partially conducting state. Due to its higher impedance, Q3 experiences increased power loss and heat generation. Simultaneously, the PWM-DR-A signal is controlled identically, ensuring a small duty cycle. This effectively makes the second and third switching transistors Q2 and Q3 act as loads, preventing current from flowing into the motor and ensuring the vehicle remains completely stationary and safe. The heat generated by the third switching transistor Q3 heats the coolant, which in turn heats the battery.

[0082] like Figure 6 As shown, one end of the two capacitors connected in the drive branch 201 corresponding to the second switch Q2 can be connected to phase U, as follows. Figure 7 As shown, one end of the two capacitors connected in the drive branch 201 corresponding to the third switch Q3 can be connected to the negative battery.

[0083] Similarly, in the drive branch 201 corresponding to the fourth switch Q4, one end of the two capacitors connected together can be connected to phase V; in the drive branch 201 corresponding to the fifth switch Q5, one end of the two capacitors connected together can be connected to the negative battery. In the drive branch 201 corresponding to the sixth switch Q6, one end of the two capacitors connected together can be connected to phase W; and in the drive branch 201 corresponding to the seventh switch Q7, one end of the two capacitors connected together can be connected to the negative battery.

[0084] In summary, the heating device provided in this application includes several heating circuits and a switching transistor drive circuit. The heating circuits include several switching transistors, and the switching transistor drive circuits include several drive branches, each of which drives a corresponding switching transistor. When the drive branch drives the switching transistor to partially conduct, the switching transistor itself generates heat, which the coolant can carry away to heat the battery. Thus, the heat generated by the incomplete conduction of the switching transistor can heat the battery without the need for a heat pump or similar equipment. Compared to existing heat pump heating solutions, this application reduces electrical costs and installation space, which is beneficial for weight reduction in electric vehicles.

[0085] Due to the complexity of the situation, it is impossible to list and elaborate on them all. Those skilled in the art should realize that there can be multiple examples based on the basic principles of the embodiments provided in this application and in combination with actual situations. Without sufficient creative effort, all of them should be within the scope of this application.

[0086] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0087] The heating device provided in this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0088] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

Claims

1. A heating device, characterized in that, include: A first number of heating circuits and a first number of switching transistor drive circuits, each corresponding to one of the heating circuits; each heating circuit is connected in parallel with a power battery; each heating circuit includes a second number of switching transistors; each switching transistor drive circuit includes a second number of drive branches; each drive branch corresponds to one of the switching transistors, and the signal output terminal of each drive branch is connected to the control terminal of the corresponding switching transistor.

2. The heating device according to claim 1, characterized in that, The drive branch includes: A drive power supply circuit and a switching transistor isolation driver are provided. The control terminal of the drive power supply circuit is connected to a controller, the power output terminal of the drive power supply circuit is connected to the switching transistor isolation driver, the control terminal of the switching transistor isolation driver is connected to the controller, and the output terminal of the switching transistor isolation driver serves as the signal output terminal of the drive branch and is connected to the control terminal of the corresponding switching transistor in the drive branch.

3. The heating device according to claim 2, characterized in that, The drive power supply circuit includes: First switching transistor, transformer and rectifier circuit; The first terminal of the first switching transistor is connected to the controller, the second terminal of the first switching transistor is grounded, the third terminal of the first switching transistor is connected to one end of the primary winding of the transformer, the other end of the primary winding of the transformer is connected to the auxiliary power supply, the two ends of the secondary winding of the transformer are connected to the rectifier circuit, and the output terminal of the rectifier circuit serves as the output terminal of the drive power supply circuit.

4. The heating device according to claim 3, characterized in that, The rectifier circuit includes: First diode and second diode; The anode of the first diode is connected to one end of the secondary winding of the transformer, and the cathode of the first diode serves as the first output terminal of the drive power supply circuit. The cathode of the second diode is connected to the other end of the secondary winding of the transformer, and the anode of the second diode serves as the second output terminal of the drive power supply circuit.

5. The heating device according to claim 4, characterized in that, The drive power supply circuit also includes: A filter circuit; the filter circuit is connected to the output terminal of the rectifier circuit.

6. The heating device according to claim 5, characterized in that, The filtering circuit includes: First capacitor and second capacitor; One end of the first capacitor is connected to the cathode of the first diode, the other end of the first capacitor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the anode of the second diode.

7. The heating device according to claim 1, characterized in that, The heating device includes a first heating circuit, a second heating circuit, and a third heating circuit; the first heating circuit, the second heating circuit, and the third heating circuit are connected in parallel with the power battery.

8. The heating device according to claim 7, characterized in that, The first heating circuit includes: a second switching transistor and a third switching transistor; The first end of the second switch is connected to the signal output terminal of the corresponding drive branch, the second end of the second switch is connected to the third end of the third switch, the third end of the second switch is connected to one end of the power battery, the first end of the third switch is connected to the signal output terminal of the corresponding drive branch, and the second end of the third switch is connected to the other end of the power battery.

9. The heating device according to claim 7, characterized in that, The second heating circuit includes: a fourth switching transistor and a fifth switching transistor; The first end of the fourth switch is connected to the signal output terminal of the corresponding drive branch, the second end of the fourth switch is connected to the third end of the fifth switch, the third end of the fourth switch is connected to one end of the power battery, the first end of the fifth switch is connected to the signal output terminal of the corresponding drive branch, and the second end of the fifth switch is connected to the other end of the power battery.

10. The heating device according to claim 7, characterized in that, The third heating circuit includes: a sixth switching transistor and a seventh switching transistor; The first end of the sixth switch is connected to the signal output terminal of the corresponding drive branch, the second end of the sixth switch is connected to the third end of the seventh switch, the third end of the sixth switch is connected to one end of the power battery, the first end of the seventh switch is connected to the signal output terminal of the corresponding drive branch, and the second end of the seventh switch is connected to the other end of the power battery.

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