Heater circuit and heater

Abstract

The utility model provides a heater circuit and a heater. The circuit comprises a driving module, a filtering module, a voltage conversion module, a voltage sampling module and a heating assembly. A first input end of the filtering module is connected with a high-voltage anode, a second input end is connected with a high-voltage cathode, a first output end is connected with a first input end of the voltage conversion module, and a second output end is connected with a second output end of the voltage conversion module; the second input end of the voltage conversion module is connected with the output end of the driving module, the first output end is connected with the first end of the heating assembly, and the second output end is connected with the second end of the heating assembly; the first input end of the voltage sampling module is connected with the first end of the heating assembly, the second input end is connected with the second end of the heating assembly, and the output end is connected with the micro-control unit; the input end of the driving module is connected with the micro-control unit; the driving module sends a pulse width modulation signal to the voltage conversion module, and the voltage conversion module converts the pulse width signal into linear voltage and outputs the linear voltage to the heating assembly. The heater efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of automotive heaters. Specifically, it relates to a heater circuit and a heater. Background Art

[0002] Currently, automotive heater controllers use Insulated Gate Bipolar Transistors (IGBTs) for Pulse Width Modulation (PWM). The microcontroller unit sends PWM instructions to the drive circuit, and the drive circuit amplifies the waveform sent by the MCU to drive the IGBT switch, enabling the heating component to be continuously powered on and off, achieving the effect of power control.

[0003] Since the power of the heating component must meet the requirements for use under the highest vehicle voltage and the lowest vehicle voltage, power waste occurs when the heating component is used under the highest vehicle voltage, and voltage withstand waste occurs when it is used under the lowest vehicle voltage. Additionally, to prevent energy fluctuations in the high-voltage circuit caused by IGBT switching, a filter circuit is added in front of the IGBT. When the IGBT is turned off, the filter circuit stores energy, and when the IGBT is turned on, the energy stored in the filter capacitor is used to balance the energy fluctuations of the high-voltage bus. However, the switching rate of the IGBT is very slow, generally only dozens or hundreds of Hz, resulting in a high energy consumption for each PWM high level, requiring the filter circuit to store higher energy at one time, that is, larger capacitors and inductors in the filter circuit, increasing the cost of the automotive heater.

[0004] Therefore, there are certain limitations in the automotive heater controllers in the prior art. Summary of the Utility Model

[0005] The purpose of this application is to provide a heater circuit and a heater to address the practical problems of low energy conversion efficiency and high cost of heaters in the prior art, in view of the deficiencies in the above prior art.

[0006] To achieve the above objective, the technical solutions adopted in the embodiments of this application are as follows:

[0007] In a first aspect, an embodiment of this application provides a heater circuit, including: a drive module, a filter module, a voltage conversion module, a voltage sampling module, and a heating component;

[0008] The first input terminal of the filter module is connected to the high-voltage positive electrode, the second input terminal of the filter module is connected to the high-voltage negative electrode, the first output terminal of the filter module is connected to the first input terminal of the voltage conversion module, and the second output terminal of the filter module is connected to the second output terminal of the voltage conversion module;

[0009] The second input terminal of the voltage conversion module is connected to the output terminal of the drive module, the first output terminal of the voltage conversion module is connected to the first end of the heating component, and the second output terminal of the voltage conversion module is connected to the second end of the heating component;

[0010] The first input terminal of the voltage sampling module is connected to the first end of the heating component, the second input terminal of the voltage sampling module is connected to the second end of the heating component, and the output terminal of the voltage sampling module is connected to the micro control unit;

[0011] The input terminal of the drive module is connected to the micro control unit;

[0012] The drive module is configured to send a pulse width modulation signal to the voltage conversion module under the control of the micro control unit, and the voltage conversion module is configured to convert the pulse width modulation signal into a linear voltage and output the linear voltage to the heating component.

[0013] As an optional implementation manner, the filtering module includes: a first capacitor, a second capacitor, and a common mode inductor;

[0014] The first end of the first capacitor is connected to the high voltage positive electrode, and the second end of the first capacitor is connected to the high voltage negative electrode;

[0015] The first end of the common mode inductor is connected to the high voltage positive electrode, the second end of the common mode inductor is connected to the high voltage negative electrode, the third end of the common mode inductor is connected to the first end of the second capacitor and the first input terminal of the voltage conversion module, and the fourth end of the common mode inductor is connected to the second end of the second capacitor and the second output terminal of the voltage conversion module;

[0016] The first end of the second capacitor is connected to the first input terminal of the voltage conversion module, and the second end of the second capacitor is connected to the second output terminal of the voltage conversion module.

[0017] As an optional implementation manner, the voltage conversion module includes: a first silicon carbide metal oxide semiconductor field effect transistor, a unidirectional conduction unit, a first inductor, and a third capacitor;

[0018] The drain of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the third end of the common mode inductor and the first end of the second capacitor, the gate of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the first output terminal of the drive module, and the source of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the first end of the first inductor and the first end of the unidirectional conduction unit;

[0019] The first end of the unidirectional conduction unit is connected to the first end of the first inductor, and the second end of the unidirectional conduction unit is connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor, and the first output end of the voltage sampling module;

[0020] The second end of the first inductor is connected to the first end of the third capacitor and the first end of the heating component;

[0021] The first end of the third capacitor is connected to the first end of the heating component, and the second end of the third capacitor is connected to the second end of the heating component.

[0022] As an alternative implementation, the unidirectional conduction unit is a diode;

[0023] The first end of the diode is connected to the source of the first silicon carbide metal oxide semiconductor field effect transistor and the first end of the first inductor;

[0024] The second end of the diode is connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor, and the first output end of the voltage sampling module.

[0025] As an alternative implementation, the unidirectional conduction unit is a second silicon carbide metal oxide semiconductor field effect transistor;

[0026] The drain of the second silicon carbide metal oxide semiconductor field effect transistor is connected to the source of the first silicon carbide metal oxide semiconductor field effect transistor and the first end of the first inductor;

[0027] The gate of the second silicon carbide metal oxide semiconductor field effect transistor is connected to the second output end of the drive module;

[0028] The source of the second silicon carbide metal oxide semiconductor field effect transistor is connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor, and the first output end of the voltage sampling module.

[0029] As an alternative implementation, the pulse width modulation signal applied to the gate of the first silicon carbide metal oxide semiconductor field effect transistor has an inverse relationship with the pulse width modulation signal applied to the gate of the second silicon carbide metal oxide semiconductor field effect transistor.

[0030] As an alternative implementation, the voltage sampling module includes: a voltage sensor, a first resistor, and a second resistor;

[0031] The first end of the first resistor is connected to the first end of the heating component, and the second end of the first resistor is connected to the first end of the second resistor and the first end of the voltage sensor;

[0032] The first end of the second resistor is connected to the first end of the voltage sensor, and the second end of the second resistor is connected to the second end of the heating component;

[0033] The second end of the voltage sensor is connected to the micro control unit.

[0034] As an optional implementation, the first resistor and the second resistor are voltage dividing resistors of the voltage sampling module.

[0035] As an optional implementation, the voltage sensor is a resistive voltage divider type voltage sensor, which is used to collect the voltage across the heating component through the voltage dividing resistor and send it to the micro control unit.

[0036] In a second aspect, an embodiment of the present application provides a heater, including the heater circuit described in the first aspect above.

[0037] The beneficial effects of the present application are as follows:

[0038] The present application provides a heater circuit and a heater. A drive module, a filter module, a voltage conversion module, a voltage sampling module, and a heating component are provided in the heater circuit. The input end and the output end of the drive module are respectively connected to the micro control unit and the second input end of the voltage conversion module, and are used to send the pulse width modulation signal sent by the micro control unit to the voltage conversion module. The first input end and the second input end of the filter module are respectively connected to the high voltage positive electrode and the high voltage negative electrode, and are used to access and filter the voltage; the first output end and the second output end of the filter module are respectively connected to the first input end and the second output end of the voltage conversion module, and are used to send the filtered voltage to the voltage conversion module. The first output end and the second output end of the voltage conversion module are respectively connected to the first end and the second end of the heating component, and the pulse width modulation signal sent by the drive module is converted into a linear voltage through voltage conversion and output to the heating component, so that the voltage across the heating component is a linear voltage. The first output end and the second output end of the voltage sampling module are respectively connected to the first end and the second end of the heating component, and are used to collect the voltage across the heating component. The output end of the voltage sampling module is connected to the micro control unit, and is used to feedback the voltage across the heating component to the micro control unit, so that the micro control unit adjusts the duty cycle of the pulse width modulation signal sent to the drive module according to the voltage across the heating component feedback by the voltage sampling module, and further adjusts the voltage across the heating component after conversion by the voltage conversion module, realizing the closed-loop control of the linear voltage across the heating component. Avoiding power waste of the heater under high voltage and withstand voltage waste under low voltage, and improving the energy conversion efficiency of the heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained based on these drawings.

[0040] Figure 1 It is a schematic structural diagram of the heater circuit provided by the embodiment of the present application;

[0041] Figure 2 It is a schematic structural diagram of the filtering module in the heater circuit provided by the embodiment of the present application;

[0042] Figure 3 It is a schematic structural diagram of the voltage conversion module in the heater circuit provided by the embodiment of the present application;

[0043] Figure 4 It is a schematic structural diagram of the unidirectional conduction unit of the voltage conversion module in the heater circuit provided by the embodiment of the present application;

[0044] Figure 5 It is another schematic structural diagram of the unidirectional conduction unit of the voltage conversion module in the heater circuit provided by the embodiment of the present application;

[0045] Figure 6 It is a schematic structural diagram of the voltage sampling module in the heater circuit provided by the embodiment of the present application.

[0046] Icon: Drive module: 11; Filter module: 12; Voltage conversion module: 13; Voltage sampling module: 14; Heating component: 15; Micro control unit: 16; First capacitor: C1; Second capacitor: C2; Common mode inductor: LF; First silicon carbide metal oxide semiconductor field effect transistor: SIC MOSFET1; Unidirectional conduction unit: 131; First inductor: L1; Third capacitor: C3; Diode: D; Second silicon carbide metal oxide semiconductor field effect transistor: SIC MOSFET2; Voltage sensor: Voltage_Sensor; First resistor: R1; Second resistor: R2. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Usually, the components of the embodiments of the present application described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0048] Accordingly, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0049] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the present application, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0050] In the description of the present application, unless otherwise clearly specified and limited, the terms "arranged", "connected", and "coupled" shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0051] Currently, the power of the heating component in an automotive heater needs to meet the requirements for use at the highest vehicle voltage and the lowest vehicle voltage. When the heating component is used at the highest vehicle voltage, power waste will occur, and when it is used at the lowest vehicle voltage, voltage withstand waste will occur. Moreover, in order to prevent energy fluctuations generated in the high-voltage circuit caused by the IGBT switch in the heater, it is necessary to set relatively large capacitors and inductors in the filter circuit, increasing the cost of the automotive heater.

[0052] Based on the above problems, the embodiment of the present application provides a heater circuit, which includes a driving module, a filtering module, a voltage conversion module, a voltage sampling module, and a heating component. The input end of the driving module is connected to the micro control unit, and the output end is connected to the voltage conversion module. The driving module is used to send the PWM signal sent by the micro control unit to the voltage conversion module. The voltage conversion module is connected to the heating component, determines the switching frequency of the silicon carbide metal oxide semiconductor field effect transistor in the voltage conversion module based on the duty cycle of the PWM signal, converts the PWM signal into a linear voltage and outputs it to the heating component, so that the voltage across the heating component is a constant linear voltage. The voltage sampling module sends the voltage across the heating component collected to the micro control unit, so that the micro control unit adjusts the duty cycle of the PWM signal sent to the driving module according to the voltage across the heating component, and further adjusts the switching frequency of the silicon carbide metal oxide semiconductor field effect transistor in the voltage conversion module, realizing the closed-loop control of the linear voltage across the heating component, avoiding power waste of the heater under high voltage and withstand voltage waste under low voltage, and improving the energy conversion efficiency of the heater.

[0053] Figure 1 is a schematic structural diagram of the heater circuit provided by the embodiment of the present application, as Figure 1 shown, the heater circuit includes a driving module 11, a filtering module 12, a voltage conversion module 13, a voltage sampling module 14, and a heating component 15.

[0054] Optionally, referring to Figure 1 , in the heater circuit, the voltage conversion module 13 is respectively connected to the driving module 11, the filtering module 12, and the heating component 15. Among them, the driving module 11 is connected to the micro control unit 16, and is used to receive the PWM signal sent by the micro control unit 16; the voltage sampling module 14 is respectively connected to the heating component 15 and the micro control unit 16, and is used to send the voltage across the heating component 15 collected to the micro control unit 16.

[0055] The first input end of the filtering module 12 is connected to the high voltage positive electrode HV+, the second input end of the filtering module 12 is connected to the high voltage negative electrode HV-, the first output end of the filtering module 12 is connected to the first input end of the voltage conversion module 13, and the second output end of the filtering module 12 is connected to the second output end of the voltage conversion module 13.

[0056] Optionally, continuing to refer to Figure 1 , the filtering module 12 includes two input ends and two output ends. Among them, the first input end and the second input end of the filtering module 12 are respectively connected to the high voltage positive electrode HV+ and the high voltage negative electrode HV-, and are used to access the voltage and filter it. The first output end and the second output end of the filtering module 12 are respectively connected to the first input end and the second output end of the voltage conversion module 13, and are used to output the filtered voltage to the voltage conversion module 13.

[0057] The second input terminal of the voltage conversion module 13 is connected to the output terminal of the driving module 11, the first output terminal of the voltage conversion module 13 is connected to the first end of the heating component 15, and the second output terminal of the voltage conversion module 13 is connected to the second end of the heating component 15.

[0058] Optionally, continue to refer to Figure 1 , the voltage conversion module 13 includes two input terminals and two output terminals. Among them, the second input terminal of the voltage conversion module 13 is connected to the output terminal of the driving module 11 for receiving the PWM signal sent by the driving module 11. The first output terminal and the second output terminal of the voltage conversion module 13 are respectively connected to the first end and the second end of the heating component 15, so that the voltage across the heating component 15 is a linear voltage.

[0059] The first input terminal of the voltage sampling module 14 is connected to the first end of the heating component 15, the second input terminal of the voltage sampling module 14 is connected to the second end of the heating component 15, and the output terminal of the voltage sampling module 14 is connected to the micro control unit 16.

[0060] Optionally, continue to refer to Figure 1 , the voltage sampling module 14 includes two input terminals and one output terminal. Among them, the first output terminal and the second output terminal of the voltage sampling module 14 are respectively connected to the first end and the second end of the heating component 15 for collecting the voltage across the heating component 15. The output terminal of the voltage sampling module 14 is connected to the micro control unit 16 for feeding back the voltage across the heating component 15 to the micro control unit 16. The micro control unit 16 adjusts the duty cycle of the PWM signal sent to the driving module 11 according to the voltage across the heating component 15 fed back by the voltage sampling module 14, and further adjusts the voltage across the heating component after conversion by the voltage conversion module 13, so as to realize the closed-loop control of the linear voltage across the heating component.

[0061] The input terminal of the driving module 11 is connected to the micro control unit 16.

[0062] Optionally, the input terminal of the driving module 11 is connected to the micro control unit 16, and the micro control unit 16 sends a PWM signal to the driving module 11.

[0063] The driving module 11 is configured to send a pulse width modulation signal to the voltage conversion module 13 under the control of the micro control unit 16, and the voltage conversion module 13 is configured to convert the pulse width modulation signal into a linear voltage and output the linear voltage to the heating component 15.

[0064] Optionally, continue to refer to Figure 1, under the control of the PWM signal sent by the microcontroller unit 16, the drive module 11 sends the PWM signal to the voltage conversion module 13 connected to the drive module 11. The voltage conversion module 13 converts the PWM signal into a linear voltage through voltage conversion and outputs the linear voltage to the heating component 15 connected to the voltage conversion module 13, so that the voltage across the heating component 15 is the linear voltage.

[0065] In this embodiment, a drive module, a filtering module, a voltage conversion module, a voltage sampling module, and a heating component are provided in the heater circuit. The input end and the output end of the drive module are respectively connected to the microcontroller unit and the second input end of the voltage conversion module, and are used to send the pulse width modulation signal sent by the microcontroller unit to the voltage conversion module. The first input end and the second input end of the filtering module are respectively connected to the high-voltage positive electrode and the high-voltage negative electrode, and are used to access the voltage and filter it; the first output end and the second output end of the filtering module are respectively connected to the first input end and the second output end of the voltage conversion module, and are used to send the filtered voltage to the voltage conversion module. The first output end and the second output end of the voltage conversion module are respectively connected to the first end and the second end of the heating component, and convert the pulse width modulation signal sent by the drive module into a linear voltage through voltage conversion and output it to the heating component, so that the voltage across the heating component is the linear voltage. The first output end and the second output end of the voltage sampling module are respectively connected to the first end and the second end of the heating component, and are used to collect the voltage across the heating component. The output end of the voltage sampling module is connected to the microcontroller unit, and is used to feedback the voltage across the heating component to the microcontroller unit, so that the microcontroller unit adjusts the duty cycle of the pulse width modulation signal sent to the drive module according to the voltage across the heating component feedback by the voltage sampling module, and further adjusts the voltage across the heating component after conversion by the voltage conversion module, realizing the closed-loop control of the linear voltage across the heating component. Avoiding power waste of the heater under high voltage and withstand voltage waste under low voltage improves the energy conversion efficiency of the heater.

[0066] Figure 2 is a schematic structural diagram of the filtering module in the heater circuit provided by the embodiment of the present application, as Figure 2 shown, the filtering module 12 includes: a first capacitor C1, a second capacitor C2, and a common mode inductor LF.

[0067] Optionally, referring to Figure 2 , the components of the filtering module 12 include two capacitors and a common mode inductor, namely the first capacitor C1, the second capacitor C2, and the common mode inductor LF. Among them, the first capacitor C1 and the second capacitor C2 are both filtering capacitors, which are used to smooth the voltage and make the voltage more stable.

[0068] The first end of the first capacitor C1 is connected to the high-voltage positive electrode HV+, and the second end of the first capacitor C1 is connected to the high-voltage negative electrode HV-.

[0069] Optionally, continue to refer to Figure 2 , the first terminal of the first capacitor C1 serves as the first input terminal of the filtering module 12 and is connected to the high-voltage positive electrode HV+ to access the high-voltage positive electrode HV+. The second terminal of the first capacitor C1 serves as the second input terminal of the filtering module 12 and is connected to the high-voltage negative electrode HV- to access the high-voltage negative electrode HV-.

[0070] The first terminal of the common-mode inductor LF is connected to the high-voltage positive electrode HV+, the second terminal of the common-mode inductor LF is connected to the high-voltage negative electrode HV-, the third terminal of the common-mode inductor LF is connected to the first terminal of the second capacitor C2 and the first input terminal of the voltage conversion module 13, and the fourth terminal of the common-mode inductor LF is connected to the second terminal of the second capacitor C2 and the second output terminal of the voltage conversion module 13.

[0071] Optionally, continue to refer to Figure 2 , the first terminal and the second terminal of the common-mode inductor LF are respectively connected to the high-voltage positive electrode HV+ and the high-voltage negative electrode HV-. The third terminal of the common-mode inductor LF is respectively connected to the first terminal of the second capacitor C2 and the first input terminal of the voltage conversion module 13. The fourth terminal of the common-mode inductor LF is respectively connected to the second terminal of the second capacitor C2 and the second output terminal of the voltage conversion module 13. The common-mode inductor LF is used to suppress common-mode interference signals.

[0072] The first terminal of the second capacitor C2 is connected to the first input terminal of the voltage conversion module 13, and the second terminal of the second capacitor C2 is connected to the second output terminal of the voltage conversion module 13.

[0073] Optionally, continue to refer to Figure 2 , the first terminal of the second capacitor C2 serves as the first output terminal of the filtering module 12 and is connected to the first input terminal of the voltage conversion module 13. The second terminal of the second capacitor C2 serves as the second output terminal of the filtering module 12 and is connected to the second output terminal of the voltage conversion module 13, and the filtered voltage is output to the voltage conversion module 13.

[0074] In this embodiment, two filter capacitors and a common-mode inductor are respectively arranged in the filter circuit. The first end of the first capacitor serves as the first input end of the filter module and is connected to the high-voltage positive electrode, and the second end of the first capacitor serves as the second input end of the filter module and is connected to the high-voltage negative electrode. The first end and the second end of the common-mode inductor are respectively connected to the high-voltage positive electrode and the high-voltage negative electrode. The third end of the common-mode inductor is respectively connected to the first end of the second capacitor and the first input end of the voltage conversion module, and the fourth end of the common-mode inductor is respectively connected to the second end of the second capacitor and the second output end of the voltage conversion module to suppress the common-mode interference signal through the common-mode inductor. The first end of the second capacitor serves as the first output end of the filter module and is connected to the first input end of the voltage conversion module, and the second end of the second capacitor serves as the second output end of the filter module and is connected to the second output end of the voltage conversion module to output the filtered voltage to the voltage conversion module. The smoothness and stability of the voltage are improved through filtering.

[0075] Figure 3 It is a schematic structural diagram of the voltage conversion module in the heater circuit provided by the embodiment of the present application, as Figure 3 shown, the voltage conversion module 13 includes: a first silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET1, a unidirectional conduction unit 131, a first inductor L1, and a third capacitor C3.

[0076] Optionally, referring to Figure 3 , the components of the voltage conversion module 13 include a first silicon carbide metal oxide semiconductor field effect transistor (SIC Metal-Oxide-Semiconductor Field-Effect Transistor, abbreviated as SICMOSFET) SIC MOSFET1, a unidirectional conduction unit 131, a first inductor L1, and a third capacitor C3. The voltage conversion module 13 converts the PWM signal sent by the drive module 13 into a linear voltage through voltage conversion.

[0077] The drain of the first silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET1 is connected to the third end of the common-mode inductor LF and the first end of the second capacitor C2. The gate of the first silicon carbide metal oxide semiconductor field effect transistor SICMOSFET1 is connected to the first output end of the drive module 11. The source of the first silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET1 is connected to the first end of the first inductor L1 and the first end of the unidirectional conduction unit 131.

[0078] Optionally, continue to refer to Figure 3, the drain of the first SIC MOSFET, SIC MOSFET1, serves as the first input terminal of the voltage conversion module 13 and is respectively connected to the third terminal of the common mode inductor LF in the filtering module 12 and the first terminal of the second capacitor C2 for accessing the filtered voltage. The gate of the first SIC MOSFET, SIC MOSFET1, serves as the second input terminal of the voltage conversion module 13 and is connected to the output terminal of the driving module 11 for receiving the PWM signal sent by the driving module 11. The source of the first SIC MOSFET, SIC MOSFET1, is respectively connected to the first terminal of the first inductor L1 and the first terminal of the unidirectional conduction unit 131. Among them, the first SIC MOSFET, SIC MOSFET1, is used to conduct or cut off under the control of the PWM signal.

[0079] The first terminal of the unidirectional conduction unit 131 is connected to the first terminal of the first inductor L1. The second terminal of the unidirectional conduction unit 131 is connected to the second terminal of the third capacitor C3, the second terminal of the heating component 15, the second terminal of the second capacitor C2, and the first output terminal of the voltage sampling module 14.

[0080] Optionally, continue to refer to Figure 3 , the first terminal of the unidirectional conduction unit 131 is respectively connected to the source of the first SIC MOSFET, SIC MOSFET1, and the first terminal of the first inductor L1. The second terminal of the unidirectional conduction unit 131 is respectively connected to the second terminal of the third capacitor C3, the second terminal of the heating component 15, the second terminal of the second capacitor C2, and the first output terminal of the voltage sampling module 14. The unidirectional conduction unit 131 has unidirectional conductivity, conducts forward and cuts off backward, setting the current flow direction in the voltage conversion unit 13.

[0081] It should be noted that the number of ports of the unidirectional conduction unit 131 is determined by the specific conduction elements in the unidirectional conduction unit 131, and the number of ports of the unidirectional conduction unit 131 is not limited to Figure 3 the two ends in. Exemplarily, if the unidirectional conduction unit 131 is a SIC MOSFET, the unidirectional conduction unit 131 includes three ports, namely the drain, gate, and source of the SIC MOSFET.

[0082] The second terminal of the first inductor L1 is connected to the first terminal of the third capacitor C3 and the first terminal of the heating component 15.

[0083] Optionally, continue to refer to Figure 3, the first end of the first inductor L1 is respectively connected to the source electrode of the first SIC MOSFET tube SICMOSFET1 and the first end of the unidirectional conduction unit 131, and the second end of the first inductor L1 is respectively connected to the first end of the third capacitor C3 and the first end of the heating component 15. When the first SIC MOSFET tube SIC MOSFET1 is turned on, the first inductor L1 is used to impede the high-voltage current from flowing through the heating component 15 and store energy. When the first SIC MOSFET tube SIC MOSFET1 is turned off, the first inductor L1 is used to release energy through the loop formed by the unidirectional conduction unit 131, the first inductor L1, and the heating component 15, so that the voltage across the heating component 15 is a linear voltage.

[0084] The first end of the third capacitor C3 is connected to the first end of the heating component 15, and the second end of the third capacitor C3 is connected to the second end of the heating component 15.

[0085] Optionally, continue to refer to Figure 3 , the first end and the second end of the third capacitor C3 are respectively connected to the first end and the second end of the heating component 15, and the third capacitor C3 is a filter capacitor for smoothing the voltage across the heating component 15.

[0086] In this embodiment, the voltage conversion module includes a first silicon carbide metal oxide semiconductor field effect transistor, a unidirectional conduction unit, a first inductor, and a third capacitor. The gate of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the first output terminal of the driving module to receive the pulse width modulation signal sent by the driving module. The first silicon carbide metal oxide semiconductor field effect transistor is turned on or off under the control of the pulse width modulation signal. The unidirectional conductivity of the unidirectional conduction unit sets the current flow direction in the voltage conversion unit. When the first silicon carbide metal oxide semiconductor field effect transistor is turned off, the first inductor releases energy through the loop formed by the unidirectional conduction unit, the first inductor, and the heating component, so that the voltage across the heating component is a linear voltage. The two ends of the third capacitor are respectively connected to the two ends of the heating component, and the third capacitor smooths the voltage across the heating component. The voltage conversion module makes the voltage across the heating component a linear voltage through voltage conversion.

[0087] Figure 4 It is a schematic structural diagram of the unidirectional conduction unit of the voltage conversion module in the heater circuit provided by the embodiment of the present application. As Figure 4 shown, the unidirectional conduction unit 131 is a diode D.

[0088] Optionally, refer to Figure 4 , the unidirectional conduction element in the unidirectional conduction unit 131 is a diode D, and the unidirectional conduction unit 131 includes two ports.

[0089] The first terminal of the diode D is connected to the source of the first silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET1 and the first terminal of the first inductor L1.

[0090] Optionally, continue to refer to Figure 4 , the first terminal of the diode D serves as the first terminal of the unidirectional conduction unit 131 and is respectively connected to the source of the first SIC MOSFET tube SIC MOSFET1 and the first terminal of the first inductor L1.

[0091] The second terminal of the diode D is connected to the second terminal of the third capacitor C3, the second terminal of the heating component 15, the second terminal of the second capacitor C2, and the first output terminal of the voltage sampling module 14.

[0092] Optionally, continue to refer to Figure 4 , the second terminal of the diode D serves as the second terminal of the unidirectional conduction unit 131 and is respectively connected to the second terminal of the third capacitor C3, the second terminal of the heating component 15, the second terminal of the second capacitor C2, and the first output terminal of the voltage sampling module 14. The unidirectional conduction characteristic of the diode D sets the current flow direction in the voltage conversion module 13.

[0093] In this embodiment, the unidirectional conduction element in the unidirectional conduction unit is a diode. The first terminal of the diode is respectively connected to the first terminal of the first silicon carbide metal oxide semiconductor field effect transistor and the first inductor, and the second terminal of the diode is respectively connected to the second terminal of the third capacitor, the second terminal of the heating component, the second terminal of the second capacitor, and the first output terminal of the voltage sampling module. The unidirectional conduction characteristic of the diode sets the current flow direction in the voltage conversion module and realizes the freewheeling effect of the voltage conversion module.

[0094] Figure 5 It is another structural schematic diagram of the unidirectional conduction unit of the voltage conversion module in the heater circuit provided by the embodiment of the present application. As Figure 5 shown, the unidirectional conduction unit 131 is the second silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET2.

[0095] Optionally, refer to Figure 5 , the unidirectional conduction element in the unidirectional conduction unit 131 is the second SIC MOSFET tube SIC MOSFET2, and the unidirectional conduction unit 131 includes three ports.

[0096] The drain of the second silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET2 is connected to the source of the first silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET1 and the first terminal of the first inductor L1.

[0097] Optionally, continue to refer to Figure 5, the drain of the second silicon carbide metal-oxide-semiconductor field-effect transistor (SIC MOSFET2) serves as the first end of the unidirectional conduction unit 131 and is respectively connected to the source of the first SIC MOSFET (SIC MOSFET1) and the first end of the first inductor L1.

[0098] The gate of the second silicon carbide metal-oxide-semiconductor field-effect transistor (SIC MOSFET2) is connected to the second output terminal of the driving module 11.

[0099] Optionally, continuing to refer to Figure 5 , the gate of the second SIC MOSFET (SIC MOSFET2) serves as the third end of the unidirectional conduction unit 131 and is connected to the second output terminal of the driving module 11 for receiving the pulse-width modulation signal output by the second output terminal of the driving module 11.

[0100] The source of the second silicon carbide metal-oxide-semiconductor field-effect transistor (SIC MOSFET2) is connected to the second end of the third capacitor C3, the second end of the heating component 15, the second end of the second capacitor C2, and the first output terminal of the voltage sampling module 14.

[0101] Optionally, continuing to refer to Figure 5 , the source of the second SIC MOSFET (SIC MOSFET2) serves as the second end of the unidirectional conduction unit 131 and is respectively connected to the second end of the third capacitor C3, the second end of the heating component 15, the second end of the second capacitor C2, and the first output terminal of the voltage sampling module 14. The unidirectional conduction characteristic of the second SIC MOSFET (SIC MOSFET2) sets the current flow direction in the voltage conversion module 13.

[0102] In this embodiment, the unidirectional conduction element in the unidirectional conduction unit is the second silicon carbide metal-oxide-semiconductor field-effect transistor. The drain of the second silicon carbide metal-oxide-semiconductor field-effect transistor is respectively connected to the source of the first silicon carbide metal-oxide-semiconductor field-effect transistor and the first end of the first inductor. The gate of the second silicon carbide metal-oxide-semiconductor field-effect transistor is connected to the second output terminal of the driving module to receive the pulse-width modulation signal output by the second output terminal of the driving module. The source of the second silicon carbide metal-oxide-semiconductor field-effect transistor is respectively connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor, and the first output terminal of the voltage sampling module. The unidirectional conduction characteristic of the second silicon carbide metal-oxide-semiconductor field-effect transistor sets the current flow direction in the voltage conversion module, achieving the freewheeling effect of the voltage conversion module.

[0103] As an alternative embodiment, the pulse width modulation signal applied to the gate of the first silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET1 has an inverse relationship with the pulse width signal applied to the gate of the second silicon carbide metal oxide semiconductor field effect transistor SIC MOSFET2.

[0104] Optionally, continuing to refer to Figure 5 , the gate of the first SIC MOSFET tube SIC MOSFET1 is connected to the first output terminal of the driving module 11 for receiving the pulse width modulation signal sent by the first output terminal of the driving module 11. The gate of the second SIC MOSFET tube SIC MOSFET1 is connected to the second output terminal of the driving module 11 for receiving the pulse width modulation signal sent by the second output terminal of the driving module 11. The pulse width modulation signal received by the gate of the first SIC MOSFET tube SIC MOSFET1 has an inverse relationship with the pulse width signal received by the gate of the second SIC MOSFET tube SIC MOSFET2.

[0105] Specifically, when the first SIC MOSFET tube SIC MOSFET1 is turned on under the control of the pulse width modulation signal sent by the first output terminal of the driving module 11, the second SIC MOSFET tube SIC MOSFET2 is turned off under the control of the pulse width modulation signal sent by the second output terminal of the driving module 11. Correspondingly, when the second SIC MOSFET tube SIC MOSFET2 is turned on under the control of the pulse width modulation signal sent by the second output terminal of the driving module 11, the first SIC MOSFET tube SIC MOSFET1 is turned off under the control of the pulse width modulation signal sent by the first output terminal of the driving module 11, so that the first SIC MOSFET tube SIC MOSFET1 and the second SIC MOSFET tube SIC MOSFET2 are turned on in a staggered manner.

[0106] In this embodiment, by setting that the pulse width modulation signal applied to the gate of the first silicon carbide metal oxide semiconductor field effect transistor has an inverse relationship with the pulse width signal applied to the gate of the second silicon carbide metal oxide semiconductor field effect transistor, the first silicon carbide metal oxide semiconductor field effect transistor and the second silicon carbide metal oxide semiconductor field effect transistor are turned on in a staggered manner.

[0107] Figure 6 FIG. is a schematic structural diagram of a voltage sampling module in the heater circuit provided by an embodiment of the present application. As Figure 6 shown, the voltage sampling module 14 includes: a voltage sensor Voltage_Sensor, a first resistor R1, and a second resistor R2.

[0108] Optionally, referring to Figure 6 , the voltage sampling module 14 includes a voltage sensor Voltage_Sensor, a first resistor R1, and a second resistor R2. The voltage sampling module 14 collects the linear voltage across the heating component 15 through the voltage sensor Voltage_Sensor, the first resistor R1, and the second resistor R2 and feeds it back to the micro-control unit 16.

[0109] The first end of the first resistor R1 is connected to the first end of the heating component 15, and the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the first end of the voltage sensor Voltage_Sensor.

[0110] Optionally, continuing to refer to Figure 6 , the first end of the first resistor R1 serves as the first input terminal of the voltage sampling module 14 and is connected to the first end of the heating component 15; the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the first end of the voltage sensor Voltage_Sensor.

[0111] The first end of the second resistor R2 is connected to the first end of the voltage sensor Voltage_Sensor, and the second end of the second resistor R2 is connected to the second end of the heating component 15.

[0112] Optionally, continuing to refer to Figure 6 , the first end of the second resistor R2 is connected to the first end of the voltage sensor Voltage_Sensor, and the second end of the second resistor R2 serves as the second input terminal of the voltage sampling module 14 and is connected to the second end of the heating component 15.

[0113] The second end of the voltage sensor Voltage_Sensor is connected to the micro-control unit 16.

[0114] Optionally, continuing to refer to Figure 6 , the second end of the voltage sensor Voltage_Sensor is connected to the micro-control unit 16, and is used to feed back the voltage across the heating component 15 collected to the micro-control unit 16, so that the micro-control unit 16 adjusts the duty cycle of the PWM signal sent to the drive module 11 according to the voltage across the heating component 15 fed back by the voltage sensor Voltage_Sensor, that is, adjusts the switching frequency of the SIC MOSFET tube in the voltage conversion module 13, and further adjusts the linear voltage across the heating component 15.

[0115] In this embodiment, the voltage sampling module collects the linear voltage across the heating component through a voltage sensor, a first resistor, and a second resistor and feeds it back to the micro-control unit, so that the micro-control unit adjusts the duty cycle of the pulse width modulation signal sent to the drive module according to the voltage across the heating component fed back by the voltage sensor, adjusts the switching frequency of the silicon carbide metal oxide semiconductor field effect transistor in the voltage conversion module, and further adjusts the linear voltage across the heating component, realizing the closed-loop control of the linear voltage across the heating component.

[0116] As an alternative implementation, the first resistor R1 and the second resistor R2 are voltage-dividing resistors of the voltage sampling module 14.

[0117] Optionally, continuing to refer to Figure 6 , both the first resistor R1 and the second resistor R2 are voltage-dividing resistors of the voltage sampling module 14. The voltage across the heating component 15 is divided using the principle of resistor voltage division, so that the voltage across the heating component 15 is within the measurable range.

[0118] In this embodiment, both the first resistor and the second resistor in the voltage sampling module are voltage-dividing resistors. The voltage across the heating component is divided using the principle of resistor voltage division, so that the voltage across the heating component is within the measurable range, facilitating the voltage sensor to collect the linear voltage across the heating component.

[0119] As an alternative implementation, the voltage sensor Voltage_Sensor is a resistor voltage division type voltage sensor, which is used to collect the voltage across the heating component 15 through the voltage-dividing resistor and send it to the micro-control unit 16.

[0120] Optionally, continuing to refer to Figure 6 , the voltage sensor Voltage_Sensor is a resistor voltage division type voltage sensor. The first end of the voltage sensor Voltage_Sensor is respectively connected to the second end of the first resistor R1 and the first end of the second resistor R2. The voltage sensor Voltage_Sensor collects the voltage across the heating component 15 through the two voltage-dividing resistors, the first resistor R1 and the second resistor R2, in the voltage acquisition module 14, and feeds back the collected voltage across the heating component 15 to the micro-control unit 16.

[0121] In this embodiment, the resistor voltage division type voltage sensor collects the voltage across the heating component through the voltage-dividing resistor and feeds back the collected voltage across the heating component to the micro-control unit, so that the micro-control unit performs closed-loop control on the voltage across the heating component.

[0122] This application also provides a heater, including the heater circuit described in the foregoing embodiment.

[0123] The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application.

Claims

1. A heater circuit, characterized in that: include: Driving module, filtering module, voltage conversion module, voltage sampling module and heating component; The first input end of the filter module is connected to the high voltage positive electrode, the second input end of the filter module is connected to the high voltage negative electrode, the first output end of the filter module is connected to the first input end of the voltage conversion module, and the second output end of the filter module is connected to the second output end of the voltage conversion module; The second input end of the voltage conversion module is connected to the output end of the driving module, the first output end of the voltage conversion module is connected to the first end of the heating component, and the second output end of the voltage conversion module is connected to the second end of the heating component; The first input end of the voltage sampling module is connected to the first end of the heating component, the second input end of the voltage sampling module is connected to the second end of the heating component, and the output end of the voltage sampling module is connected to the micro control unit; The input end of the driving module is connected to the micro control unit; The driving module is used to send a pulse width modulation signal to the voltage conversion module under the control of the micro control unit, and the voltage conversion module is used to convert the pulse width modulation signal into a linear voltage and output the linear voltage to the heating component.

2. The circuit according to claim 1, characterized in that The filtering module includes: a first capacitor, a second capacitor and a common mode inductor; The first end of the first capacitor is connected to the high voltage positive electrode, and the second end of the first capacitor is connected to the high voltage negative electrode; The first end of the common-mode inductor is connected to the high-voltage positive electrode, the second end of the common-mode inductor is connected to the high-voltage negative electrode, the third end of the common-mode inductor is connected to the first end of the second capacitor and the first input end of the voltage conversion module, and the fourth end of the common-mode inductor is connected to the second end of the second capacitor and the second output end of the voltage conversion module; A first end of the second capacitor is connected to a first input end of the voltage conversion module, and a second end of the second capacitor is connected to a second output end of the voltage conversion module.

3. The circuit according to claim 2, characterized in that The voltage conversion module includes: a first silicon carbide metal oxide semiconductor field effect transistor, a unidirectional conduction unit, a first inductor and a third capacitor; The drain of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the third end of the common mode inductor and the first end of the second capacitor, the gate of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the first output end of the driving module, and the source of the first silicon carbide metal oxide semiconductor field effect transistor is connected to the first end of the first inductor and the first end of the unidirectional conductive unit; The first end of the one-way conductive unit is connected to the first end of the first inductor, and the second end of the one-way conductive unit is connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor, and the first output end of the voltage sampling module; The second end of the first inductor is connected to the first end of the third capacitor and the first end of the heating component; The first end of the third capacitor is connected to the first end of the heating component, and the second end of the third capacitor is connected to the second end of the heating component.

4. The circuit according to claim 3, characterized in that The unidirectional conductive unit is a diode; The first end of the diode is connected to the source of the first silicon carbide metal oxide semiconductor field effect transistor and the first end of the first inductor; The second end of the diode is connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor, and the first output end of the voltage sampling module.

5. The circuit according to claim 3, characterized in that The unidirectional conductive unit is a second silicon carbide metal oxide semiconductor field effect transistor; The drain of the second silicon carbide metal oxide semiconductor field effect transistor is connected to the source of the first silicon carbide metal oxide semiconductor field effect transistor and the first end of the first inductor; The gate of the second silicon carbide metal oxide semiconductor field effect transistor is connected to the second output terminal of the driving module; The source of the second silicon carbide metal oxide semiconductor field effect transistor is connected to the second end of the third capacitor, the second end of the heating component, the second end of the second capacitor and the first output end of the voltage sampling module.

6. The circuit according to claim 5, characterized in that The pulse width modulation signal connected to the gate of the first silicon carbide metal oxide semiconductor field effect transistor and the pulse width signal connected to the gate of the second silicon carbide metal oxide semiconductor field effect transistor have an inverse relationship.

7. The circuit according to claim 1, characterized in that The voltage sampling module includes: a voltage sensor, a first resistor and a second resistor; The first end of the first resistor is connected to the first end of the heating component, and the second end of the first resistor is connected to the first end of the second resistor and the first end of the voltage sensor; A first end of the second resistor is connected to a first end of the voltage sensor, and a second end of the second resistor is connected to a second end of the heating component; The second end of the voltage sensor is connected to the micro control unit.

8. The circuit according to claim 7, characterized in that The first resistor and the second resistor are voltage-dividing resistors of the voltage sampling module.

9. The circuit according to claim 8, characterized in that The voltage sensor is a resistor voltage divider type voltage sensor, which is used to collect the voltage across the heating component through the voltage divider resistor and send it to the micro control unit.

10. A heater, characterized in that: include: A heater circuit as claimed in any one of claims 1 to 9.

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