Thyristor driving circuit
By introducing a main control chip and a temperature sampling circuit into the thyristor drive circuit, the duty cycle of low-frequency and high-frequency drive signals is dynamically adjusted, solving the problem of poor adaptability of traditional drive circuits at different temperatures, and achieving stability and low loss of thyristors at different temperatures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2026-04-03
AI Technical Summary
Traditional thyristor drive circuits cannot adapt to different temperature environments, resulting in high losses and high costs at low temperatures, or failure to trigger at low temperatures, thus failing to meet the application requirements of low-temperature scenarios.
Design a thyristor driving circuit that outputs low-frequency and high-frequency driving signals through a main control chip and adjusts the duty cycle of the driving signal in conjunction with a temperature sampling circuit to regulate the trigger current. The circuit includes an AND gate circuit, a power driving circuit, and an isolation driving circuit. It utilizes an NTC thermistor to sample the temperature, thereby realizing temperature sensing of the thyristor and dynamic adjustment of the driving signal.
To ensure reliable conduction of thyristors at different temperatures, improve drive stability, reduce thyristor losses, and adapt to application requirements in different temperature environments.
Smart Images
Figure CN224083526U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of thyristor technology, and in particular to a thyristor driving circuit. Background Technology
[0002] A thyristor, also known as a silicon controlled rectifier (SCR), is a power semiconductor device with three PN junctions. A thyristor has three terminals: anode, cathode, and gate. It possesses the characteristics of a silicon rectifier, operating under high voltage and high current conditions, and is widely used in high-power rectification, AC voltage regulation, STS (Static Transfer Switch), inverters, frequency converters, and other electronic circuits. A thyristor is a current-controlled device; when an external drive circuit inputs a drive current to the thyristor gate and the anode voltage is higher than the cathode voltage, a strong positive feedback is formed inside the thyristor, causing it to conduct.
[0003] For thyristors, the required trigger current varies depending on the operating temperature. For example, the trigger current required for a thyristor at -40°C is 2 to 3 times that at 25°C, and 3 to 4 times that at 125°C. Traditional thyristor drive circuits have a fixed drive current. Designing the drive circuit for a lower temperature (e.g., -40°C) results in higher losses and costs. Designing the drive circuit for a higher temperature (e.g., 25°C) may prevent the thyristor from triggering at lower temperatures (e.g., -40°C), thus failing to meet the application requirements in low-temperature scenarios. Utility Model Content
[0004] This application provides a thyristor driving circuit that can adjust the trigger current of the thyristor, improve the stability of driving the thyristor, and reduce the loss of the thyristor.
[0005] This application provides a thyristor driving circuit, including:
[0006] The main control chip is configured to output low-frequency drive signals and high-frequency drive signals;
[0007] The driving circuit is configured to generate a forward voltage signal based on the low-frequency driving signal and the high-frequency driving signal, the forward voltage signal being output to a thyristor to drive the thyristor.
[0008] A temperature sampling circuit is configured to sample the temperature of the thyristor to obtain a sampling signal, and output the sampling signal to the main control chip so that the main control chip adjusts the duty cycle of the low-frequency drive signal and / or the high-frequency drive signal.
[0009] In some embodiments, the driving circuit includes:
[0010] An AND gate circuit is configured to perform an AND comparison on the low-frequency drive signal and the high-frequency drive signal, and output a power drive signal;
[0011] A power drive circuit is configured to amplify the power drive signal and output an amplified signal;
[0012] An isolation drive circuit is configured to generate the forward voltage signal based on the control of the amplified signal.
[0013] In some embodiments, the low-frequency drive signal includes three drive signals, the high-frequency drive signal includes one drive signal, and the power drive signal includes three drive signals.
[0014] In some embodiments, the AND gate circuit includes an AND gate chip, the AND gate chip comprising:
[0015] Three low-frequency input pins, each of which is configured to input one low-frequency drive signal;
[0016] Three high-frequency input pins, each of which is configured to input the high-frequency drive signal;
[0017] Three output pins, each of which is configured to output one of the power drive signals.
[0018] In some embodiments, the power drive circuit includes three power drive units, each of which is electrically connected to the AND gate circuit and the isolation drive circuit.
[0019] The power drive unit includes a power drive chip, which is configured to amplify the power drive signal and output an amplified signal.
[0020] In some embodiments, the isolation drive circuit includes three isolation drive units, each of which is electrically connected to one of the power drive chips;
[0021] The isolation drive unit includes:
[0022] A MOS transistor, the gate of which is electrically connected to the power drive chip, and the source of which is grounded, are used to control the MOS transistor to turn on and off.
[0023] A transformer comprising an electromagnetically coupled primary coil and a secondary coil, one end of the primary coil being electrically connected to the drain of the MOS transistor, the other end of the primary coil being connected to an auxiliary power supply, and the secondary coil being configured to generate the forward voltage signal.
[0024] In some embodiments, the positive half-axis waveform of the forward voltage signal is the same as the positive half-axis waveform of the amplified signal.
[0025] In some embodiments, the isolation drive unit further includes a rectifier circuit electrically connected to the secondary coil, the rectifier circuit being configured to rectify the forward voltage signal, the rectified forward voltage signal being output to a thyristor to drive the thyristor.
[0026] In some embodiments, the temperature sampling circuit includes an NTC thermistor disposed close to the thyristor to sample the temperature of the thyristor.
[0027] In some embodiments, the thyristor driving circuit further includes:
[0028] An auxiliary power supply is electrically connected to the main control chip, the drive circuit, and the temperature sampling circuit. The auxiliary power supply is configured to supply power to the main control chip, the drive circuit, and the temperature sampling circuit.
[0029] The thyristor driving circuit of this application embodiment can adjust the duty cycle of the low-frequency driving signal and / or the high-frequency driving signal according to the temperature change of the thyristor, thereby adjusting the trigger current of the thyristor. The thyristor can reliably conduct at different operating temperatures. Therefore, the solution of this application can improve the stability of thyristor driving and reduce thyristor losses. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the 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.
[0031] Figure 1 This is a schematic diagram of the first structure of the thyristor driving circuit according to an embodiment of this application.
[0032] Figure 2 This is a schematic diagram of a second structure of the thyristor driving circuit according to an embodiment of this application.
[0033] Figure 3 This is a schematic diagram of a third structure of the thyristor driving circuit according to an embodiment of this application.
[0034] Figure 4 This is a schematic diagram of the AND gate circuit of the thyristor driving circuit in an embodiment of this application.
[0035] Figure 5This is a schematic diagram of the power drive circuit and isolation drive circuit of the thyristor drive circuit in an embodiment of this application.
[0036] Figure 6 This is a schematic diagram of the temperature sampling circuit of the thyristor drive circuit in an embodiment of this application. Detailed Implementation
[0037] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0038] This application provides a thyristor driving circuit that can adjust the thyristor's trigger current according to the temperature change of the thyristor. When the thyristor is operating in a low-temperature environment, the trigger current can be increased to ensure stable triggering of the thyristor and improve the stability of the thyristor drive; when the thyristor is operating in a high-temperature environment, the trigger current can be reduced to reduce the thyristor's losses.
[0039] refer to Figure 1 , Figure 1 This is a schematic diagram of a first structure of the thyristor driving circuit 100 according to an embodiment of this application. The thyristor driving circuit 100 includes a main control chip 10, a driving circuit 20, and a temperature sampling circuit 30. The main control chip 10 is electrically connected to the driving circuit 20, and the driving circuit 20 is electrically connected to the thyristor (Silicon Controlled Rectifier, also known as a thyristor, or SCR) 200. The driving circuit 20 is used to drive the thyristor 200. The temperature sampling circuit 30 is electrically connected to the main control chip 10.
[0040] The main control chip 10 is configured to output a low-frequency drive signal and a high-frequency drive signal. Both the low-frequency drive signal and the high-frequency drive signal are PWM (Pulse Width Modulation) signals. The drive circuit 20 is configured to generate a forward voltage signal based on the low-frequency drive signal and the high-frequency drive signal, and output the forward voltage signal to the thyristor 200 to drive the thyristor 200.
[0041] In some embodiments, the low-frequency drive signal includes three drive signals, such as PWM_A_DSP, PWM_B_DSP, and PWM_C_DSP. The high-frequency drive signal includes one drive signal, such as PWM_HF_DRY_DSP.
[0042] The temperature sampling circuit 30 is configured to sample the temperature of the thyristor 200 to obtain a sampling signal, and output the sampling signal to the main control chip 10 so that the main control chip 10 can adjust the duty cycle of the low-frequency drive signal and / or the high-frequency drive signal.
[0043] For example, when the temperature corresponding to the sampling signal is low, the main control chip 10 can increase the duty cycle of the drive signal to increase the trigger current output to the thyristor 200; when the temperature corresponding to the sampling signal is high, the main control chip 10 can decrease the duty cycle of the drive signal to decrease the trigger current output to the thyristor 200. In practical applications, the main control chip 10 can adjust one of the low-frequency drive signal and the high-frequency drive signal, for example, adjusting only the low-frequency drive signal, or adjusting only the high-frequency drive signal; it can also adjust both the low-frequency drive signal and the high-frequency drive signal simultaneously.
[0044] In some embodiments, the temperature sampling circuit 30 includes an NTC (Negative Temperature Coefficient) thermistor. It is understood that the resistance of an NTC thermistor changes with temperature, therefore, the NTC thermistor can be used for temperature sampling. The NTC thermistor is positioned close to the thyristor 200 to sample the temperature of the thyristor 200. For example, the NTC thermistor can be attached to the thyristor 200 for convenient temperature sampling.
[0045] In some embodiments, reference Figure 2 , Figure 2 This is a schematic diagram of a second structure of the thyristor driving circuit 100 according to an embodiment of this application. The driving circuit 20 includes an AND gate circuit 21, a power driving circuit 22, and an isolation driving circuit 23.
[0046] The AND gate circuit 21 is electrically connected to the main control chip 10. The AND gate circuit 21 is configured to perform an AND comparison between the low-frequency drive signal and the high-frequency drive signal output by the main control chip 10, and output a power drive signal. In some embodiments, the AND gate circuit 21 can be a four-way two-input AND gate circuit.
[0047] Understandably, in some embodiments, when the low-frequency drive signal output by the main control chip 10 includes three drive signals and the high-frequency drive signal includes one drive signal, the power drive signal output by the AND gate circuit 21 also includes three drive signals, such as PWM_SCR_A, PWM_SCR_B, and PWM_SCR_C.
[0048] The power drive circuit 22 is electrically connected to the AND gate circuit 21. The power drive circuit 22 is configured to amplify the power drive signal output by the AND gate circuit 21 and output an amplified signal.
[0049] The isolation drive circuit 23 is electrically connected to the power drive circuit 22, and is also electrically connected to the thyristor 200. The isolation drive circuit 23 is configured to generate the aforementioned forward voltage signal based on the control of the amplified signal output from the power drive circuit 22. The forward voltage signal is output to the thyristor 200 to drive the thyristor 200.
[0050] In some embodiments, reference Figure 3 , Figure 3 This is a schematic diagram of a third structure of the thyristor drive circuit 100 according to an embodiment of this application.
[0051] The thyristor drive circuit 100 also includes an auxiliary power supply 40. The auxiliary power supply 40 is electrically connected to the main control chip 10, the drive circuit 20, and the temperature sampling circuit 30. The auxiliary power supply 40 is configured to supply power to the main control chip 10, the drive circuit 20, and the temperature sampling circuit 30. For example, the auxiliary power supply 40 can be used to supply power to the main control chip 10, the AND gate circuit 21, the power drive circuit 22, the isolation drive circuit 23, and the temperature sampling circuit 30.
[0052] In some embodiments, reference Figure 4 , Figure 4 This is a schematic diagram of the AND gate circuit 21 of the thyristor drive circuit 100 according to an embodiment of this application. The AND gate circuit 21 includes an AND gate chip IC1.
[0053] The AND gate chip IC1 includes three low-frequency input pins, such as low-frequency input pins 1A, 2A, and 3A. Each low-frequency input pin is configured to input one low-frequency drive signal. For example, pin 1A is configured to input the low-frequency drive signal PWM_A_DSP, pin 2A is configured to input the low-frequency drive signal PWM_B_DSP, and pin 3A is configured to input the low-frequency drive signal PWM_C_DSP. In practical applications, the low-frequency drive signal PWM_A_DSP can be input to pin 1A via resistor R1, the low-frequency drive signal PWM_B_DSP can be input to pin 2A via resistor R3, and the low-frequency drive signal PWM_C_DSP can be input to pin 3A via resistor R6.
[0054] The AND gate chip IC1 also includes three high-frequency input pins, such as high-frequency input pins 1B, 2B, and 3B. Each high-frequency input pin is configured to input a high-frequency drive signal. For example, pins 1B, 2B, and 3B are all configured to input the high-frequency drive signal PWM_HF_DRY_DSP. In practical applications, the high-frequency drive signal PWM_HF_DRY_DSP can be input to pin 1B via resistor R2, to pin 2B via resistor R4, and to pin 3B via resistor R5.
[0055] The AND gate chip IC1 also includes three output pins, such as output pins 1Y, 2Y, and 3Y. Each output pin is configured to output a power drive signal. For example, pin 1Y is configured to output the power drive signal PWM_SCR_A, pin 2Y is configured to output the power drive signal PWM_SCR_B, and pin 3Y is configured to output the power drive signal PWM_SCR_C.
[0056] In some embodiments, the AND gate chip IC1 may also include other pins, such as pins 4A, 4B, 4Y, VCC, and GND. Pins 4A and GND are grounded and can be understood as ground pins. Pins 4B and VCC are connected to the auxiliary power supply 40 and can be understood as power supply pins. Pin 4Y is left floating.
[0057] The thyristor drive circuit 100 of this application embodiment processes the three power drive signals PWM_SCR_A, PWM_SCR_B, and PWM_SCR_C output by AND gate 21 in a similar manner. The following description will only use the processing of power drive signal PWM_SCR_A as an example; the processing of power drive signals PWM_SCR_B and PWM_SCR_C will not be repeated.
[0058] In some embodiments, reference Figure 5 , Figure 5 This is a schematic diagram of the power drive circuit 22 and the isolation drive circuit 23 of the thyristor drive circuit 100 in an embodiment of this application.
[0059] The power drive circuit 22 includes three power drive units 221. It should be noted that... Figure 5 The following description uses only one power drive unit 221 as an example. Each power drive unit 221 is electrically connected to AND gate circuit 21 and isolation drive circuit 23. Each power drive unit 221 is configured to process one power drive signal output by AND gate circuit 21.
[0060] For example Figure 5 As shown, the power drive unit 221 can be used to process the power drive signal PWM_SCR_A. The power drive unit 221 includes a power drive chip IC2. The power drive chip IC2 is configured to amplify the power drive signal PWM_SCR_A and output an amplified signal.
[0061] In some embodiments, the power driver chip IC2 includes eight pins, such as INA, INB, OUTA, OUTB, ENA, ENB, VDD, and GND. The power drive signal PWM_SCR_A is input to pin INA through resistor R7. Resistor R7 and pin INA are grounded through resistor R8 and capacitor C1, with resistor R8 and capacitor C1 connected in parallel. Pin INB is grounded through resistor R9. Pin OUTA outputs an amplified signal through resistor R10. Pin OUTB is left floating. Pins ENA, ENB, and VDD are all connected to the auxiliary power supply 40, which can be understood as power supply pins. Pins ENA, ENB, and VDD are grounded through capacitors C2 and C3, with capacitors C2 and C3 connected in parallel. Pin GND is grounded.
[0062] In some embodiments, continue to refer to Figure 5 The isolation drive circuit 23 includes three isolation drive units 231. It should be noted that... Figure 5 The explanation will focus on a single isolation drive unit 231. Each isolation drive unit 231 is electrically connected to a power drive unit 221.
[0063] In some embodiments, the isolation drive unit 231 includes a MOS transistor (Metal Oxide Semiconductor Field Effect Transistor) Q1 and a transformer T1.
[0064] In this configuration, the gate of MOSFET Q1 is electrically connected to the power drive unit 221, for example, to a resistor R10. The gate of MOSFET Q1 and resistor R10 are grounded through resistor R11. The source of MOSFET Q1 is grounded. The drain of MOSFET Q1 is electrically connected to transformer T1. The amplified signal output by the power drive chip IC2 is used to control the turn-on and turn-off of MOSFET Q1.
[0065] Transformer T1 includes an electromagnetically coupled primary coil and a secondary coil. One end of the primary coil is electrically connected to the drain of MOSFET Q1. The other end of the primary coil is connected to auxiliary power supply 40, and can also be grounded through capacitors C4 and C5, which are connected in parallel. Diodes D1 and D2 are connected in series between the two ends of the primary coil. Diodes D1 and D2 have opposite conduction directions; for example, diode D1 is conducting towards diode D2, and diode D2 is conducting towards diode D1. Diode D2 can be a Zener diode. Diodes D1 and D2 are connected to auxiliary power supply 40 through resistor R12. The secondary coil is configured to generate the aforementioned forward voltage signal.
[0066] Therefore, by controlling the on and off states of MOSFET Q1, the voltage value of the aforementioned forward voltage signal generated by the secondary coil can be controlled, which in turn controls the corresponding current value, i.e., the magnitude of the trigger current output to thyristor 200. Thus, by adjusting the duty cycle of the low-frequency drive signal and / or high-frequency drive signal output by the main control chip 10, the magnitude of the trigger current output to thyristor 200 can be adjusted.
[0067] In some embodiments, the positive half-axis waveform of the forward voltage signal generated by the secondary coil is the same as the positive half-axis waveform of the amplified signal output by the power driver chip IC2. It should be noted that the fact that the positive half-axis waveforms of the two signals are the same is a theoretical case, that is, the case where signal delay and external interference are not considered.
[0068] In some embodiments, the isolation drive unit 231 further includes a rectifier circuit. The rectifier circuit is electrically connected to the secondary coil of the transformer T1. The rectifier circuit is configured to rectify the forward voltage signal output from the secondary coil, and the rectified forward voltage signal is used to output to the thyristor 200 to drive the thyristor 200.
[0069] For example, such as Figure 5 As shown, the secondary coil of transformer T1 may include two sub-coils.
[0070] A rectifier circuit connected to a sub-coil includes diode D3, capacitor C6, capacitor C8, resistor R13, and resistor R15. One end of the sub-coil is connected in series with diode D3 and resistor R13. Diode D3 and resistor R13 are connected to the other end of the sub-coil via capacitor C6. The output terminal of resistor R13 is connected in parallel with the other end of the sub-coil via resistor R15 and capacitor C8. A forward voltage signal is output from both ends of capacitor C8. One end of capacitor C8 outputs a signal PWM1_G acting on pin G of thyristor 200, and the other end of capacitor C8 outputs a signal PWM1_K acting on pin K of thyristor 200.
[0071] The rectifier circuit connected to the other sub-coil includes diode D4, capacitors C7 and C9, resistors R14 and R16. One end of this sub-coil is connected in series with diode D4 and resistor R14. Diode D4 and resistor R14 are connected to the other end of the sub-coil via capacitor C7. Resistor R16 and capacitor C9 are connected in parallel between the output of resistor R14 and the other end of the sub-coil. Capacitor C9 outputs a forward voltage signal. One end of capacitor C9 outputs a signal PWM2_G acting on pin G of thyristor 200, and the other end of capacitor C9 outputs a signal PWM2_K acting on pin K of thyristor 200.
[0072] In some embodiments, reference Figure 6 , Figure 6This is a schematic diagram of the temperature sampling circuit 30 of the thyristor drive circuit 100 in an embodiment of this application.
[0073] The temperature sampling circuit 30 samples the temperature of the thyristor 200 to obtain a sampling signal (e.g., a sampling signal obtained through an NTC thermistor) NTC_SCR_A. The sampling signal NTC_SCR_A is then filtered by an RC filter circuit and a voltage clamping circuit to obtain the output signal NTC_SCR_A_AD. The output signal NTC_SCR_A_AD is input to the main control chip 10 as its internal sampling signal. The main control chip 10 can then adjust the duty cycle of the low-frequency drive signal and / or the high-frequency drive signal based on the internal sampling signal.
[0074] In some embodiments, such as Figure 6 As shown, the RC filter circuit may include resistor R17, capacitor C10, and capacitor C11. One end of resistor R17 receives the sampling signal NTC_SCR_A and is connected to the auxiliary power supply 40 via pull-up resistor R18. The other end of resistor R17 is connected to the voltage clamping circuit. The two ends of resistor R17 are grounded via capacitors C10 and C11, respectively.
[0075] The voltage clamping circuit may include diodes D5 and D6. Diodes D5 and D6 are connected in series. Diodes D5 and D6 have the same conduction direction; for example, the direction in which diode D5 faces diode D6 is the conduction direction, and the direction in which diode D6 faces away from diode D5 is the conduction direction. Diodes D5 and D6 are connected to a resistor R17, which is used to output the aforementioned output signal NTC_SCR_A_AD. The other end of diode D5 is grounded. The other end of diode D6 is connected to the auxiliary power supply 40.
[0076] The thyristor drive circuit 100 of this application embodiment can adjust the duty cycle of the low-frequency drive signal and / or the high-frequency drive signal according to the temperature change of the thyristor 200, thereby adjusting the trigger current of the thyristor 200. The thyristor 200 can reliably conduct under different operating temperatures. Therefore, the solution of this application can improve the stability of the thyristor 200 drive and reduce the loss of the thyristor 200.
[0077] It should be noted that, in the embodiments of this application, "electrical connection" can be a direct connection between two electrical components or an indirect connection. For example, the electrical connection between A and B can be achieved by A and B being directly connected, or by A and B being indirectly connected through one or more other electrical components.
[0078] The thyristor driving circuit provided in the embodiments of 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 this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A thyristor drive circuit, characterized by The application relates to a thyristor drive circuit, comprising: a master chip configured to output a low-frequency drive signal and a high-frequency drive signal; a drive circuit configured to generate a forward voltage signal based on the low-frequency drive signal and the high-frequency drive signal, the forward voltage signal being used for output to a thyristor to drive the thyristor; the drive circuit comprising an AND gate circuit, a power drive circuit and an isolation drive circuit, the AND gate circuit being configured to AND compare the low-frequency drive signal and the high-frequency drive signal and output a power drive signal; the power drive circuit being electrically connected to the AND gate circuit and being configured to amplify the power drive signal and output an amplified signal; the isolation drive circuit being electrically connected to the power drive circuit and the thyristor, and being configured to generate the forward voltage signal based on control of the amplified signal; a temperature sampling circuit configured to sample a temperature of the thyristor to obtain a sampling signal and output the sampling signal to the master chip so that the master chip adjusts a duty cycle of the low-frequency drive signal and / or the high-frequency drive signal. The low-frequency drive signal comprises three drive signals, the high-frequency drive signal comprises one drive signal, and the power drive signal comprises three drive signals. The AND gate circuit comprises an AND gate chip, the AND gate chip comprising: three low-frequency input pins, each of the low-frequency input pins being configured to input one of the low-frequency drive signals; three high-frequency input pins, each of the high-frequency input pins being configured to input the high-frequency drive signal; and three output pins, each of the output pins being configured to output one of the power drive signals.
4. The thyristor drive circuit according to claim 2, wherein: the power drive circuit comprises three power drive units, each of the power drive units being electrically connected to the AND gate circuit and the isolation drive circuit; and the power drive unit comprises a power drive chip configured to amplify the power drive signal and output an amplified signal.
2. The thyristor drive circuit according to claim 1, characterized in that 5. The thyristor drive circuit according to claim 4, wherein: the isolation drive circuit comprises three isolation drive units, each of the isolation drive units being electrically connected to one of the power drive chips; and the isolation drive unit comprises: a MOS tube, a gate of the MOS tube being electrically connected to the power drive chip, a source of the MOS tube being grounded, and the amplified signal being used for controlling opening and closing of the MOS tube; and a transformer comprising an electromagnetic coupling primary coil and a secondary coil, one end of the primary coil being electrically connected to a drain of the MOS tube, the other end of the primary coil being connected to an auxiliary power supply, and the secondary coil being configured to generate the forward voltage signal.
3. The thyristor drive circuit of claim 2, characterized in that 6. The thyristor drive circuit according to claim 5, wherein: a positive half-axis waveform of the forward voltage signal is the same as a positive half-axis waveform of the amplified signal.
7. The thyristor drive circuit according to claim 5, wherein: The isolation driving unit further comprises a rectifier circuit electrically connected with the secondary coil, and configured to rectify the forward voltage signal, and the rectified forward voltage signal is used to output to the thyristor to drive the thyristor.
8. The thyristor driving circuit according to any one of claims 1 to 7, characterized in that: The temperature sampling circuit comprises an NTC thermistor arranged close to the thyristor to sample the temperature of the thyristor.
9. Thyristor drive circuit according to any one of claims 1 to 7, characterized in that Further comprising: An auxiliary power supply electrically connected with the master control chip, the driving circuit and the temperature sampling circuit, and configured to supply power to the master control chip, the driving circuit and the temperature sampling circuit.