An electrically isolated IGBT drive circuit

Abstract

This application relates to the field of IGBT drive technology, and in particular to an electrically isolated IGBT drive circuit, including an isolated IGBT power supply module, an isolated IGBT drive module, and a power conversion module. The isolated IGBT power supply module is connected to an external power source to generate isolated positive and negative power supplies, which are input to the isolated IGBT drive module. The power conversion module converts the external power supply into a working voltage to power the isolated IGBT drive module. The isolated IGBT drive module is connected to an external controller to receive PWM signals. The isolated IGBT drive module drives the IGBT to turn on / off through the positive and negative power supplies and the PWM signals. The isolated IGBT drive module includes a detection terminal connected to the collector of the external IGBT module. The isolated IGBT drive module determines the short-circuit state by the level change at the detection terminal. Because each module has a clear function and the isolation design reduces interference, the drive circuit structure is simple and highly reliable. It also has built-in short-circuit detection functionality, eliminating the need for additional circuits or equipment to monitor short-circuit conditions, thus improving the overall circuit performance.

Description

Technical Field

[0001] This application relates to the field of IGBT drive technology, and in particular to an electrically isolated IGBT drive circuit. Background Technology

[0002] In the industrial sector, electric motors, as widely used transmission devices, play a crucial role in the normal operation of industrial production. With the continuous development of industrial technology, motor control technology is also constantly advancing, and IGBT control circuits are now widely used in motor control. IGBT control circuits enable efficient and precise control in motor control, greatly improving the motor's operating performance and stability. This is of great significance for improving the efficiency and quality of industrial production, playing an irreplaceable role in many industrial production processes. Traditional IGBT drive circuits, when implementing motor control functions, often use a small transformer to convert and rectify the rectifier to generate the drive power, and then build a complex drive circuit to receive the controller's PWM signal, thereby driving the IGBT to turn on and off. This approach requires careful design of the transformer parameters and the rectifier circuit structure to ensure the generation of a suitable drive power. At the same time, many factors must be considered when building the drive circuit, such as signal transmission stability and the circuit's anti-interference capability, requiring the use of numerous electronic components to complete the circuit construction. Furthermore, traditional IGBT drive circuits typically lack short-circuit monitoring and alarm functions, necessitating additional circuitry or equipment to monitor short-circuit conditions.

[0003] Traditional IGBT driver circuits, due to their use of small transformers for conversion and rectification and the construction of complex driver circuits, result in a complex circuit construction process, requiring numerous electronic components and intricate wiring. This increases the probability of circuit failure and leads to lower reliability. Furthermore, the large number of electronic components and the complex circuit structure also result in a large overall size of the driver circuit, hindering the miniaturization and integration of devices. Summary of the Invention

[0004] This application provides an electrically isolated IGBT drive circuit, which features a simple structure, small size, high reliability, and the function of monitoring IGBT short circuits.

[0005] The above-mentioned objective of this application is achieved through the following technical solution: This application provides an electrically isolated IGBT drive circuit, including an isolated IGBT power supply module, an isolated IGBT drive module, and a power conversion module. The isolated IGBT power supply module is connected to an external power source to generate isolated positive and negative power supplies, which are input to the isolated IGBT drive module. The power conversion module converts the external power supply into a working voltage to power the isolated IGBT drive module. The isolated IGBT drive module is connected to an external controller to receive PWM signals. The isolated IGBT drive module drives the IGBT to turn on / off through the positive and negative power supplies and the PWM signals. The isolated IGBT drive module includes a detection terminal connected to the collector of the external IGBT module. The isolated IGBT drive module determines the short-circuit state by the level change at the detection terminal. Because each module has a clear function and the isolation design reduces interference, the drive circuit structure is simple and highly reliable. Furthermore, it has built-in short-circuit detection functionality, eliminating the need for additional circuitry or equipment to monitor short-circuit conditions, thus improving the overall circuit performance.

[0006] Furthermore, the isolated IGBT driver module includes an IGBT driver chip and a protection unit. The protection unit includes a resistor R7 and a diode D1. The detection terminal of the IGBT driver chip is connected to the anode of diode D1 via resistor R7, and the cathode of diode D1 is connected to the collector of the external IGBT module. The IGBT driver chip internally provides a constant current source. During normal operation, the voltage at the detection terminal will not exceed the threshold. When a short circuit occurs, if the IGBT current is too high, the voltage at the detection terminal will exceed the threshold. The IGBT driver chip determines the short circuit state by the change in the level at the detection terminal and feeds the signal back to the upper controller. Resistor R7 limits the current, preventing excessive current from flowing into the short-circuit detection terminal of the driver chip. Diode D1 can be a common rectifier diode, and its function is to prevent reverse current.

[0007] Furthermore, the protection unit includes an overvoltage protection circuit, which comprises a Zener diode D2 and a capacitor C11. The detection terminal of the IGBT driver chip is connected to the cathode of the Zener diode D2, and the anode of the Zener diode D2 is connected to the emitter of the external IGBT module. The capacitor C11 is connected in parallel across the two ends of the Zener diode D2. The breakdown voltage of the overvoltage protection circuit is less than the maximum operating voltage of the IGBT driver chip. The Zener diode is used to limit the voltage at the short-circuit detection terminal to prevent excessive voltage from damaging the driver chip, while the capacitor C11 is used for filtering to reduce voltage fluctuations.

[0008] Furthermore, the isolated IGBT power module includes an isolated DC-DC chip.

[0009] Furthermore, the isolated IGBT power module also includes a first voltage divider unit, which is connected to the feedback loop of the isolated DC-DC chip and is used to adjust the magnitude of the output positive power.

[0010] Furthermore, the isolated IGBT power module also includes a second voltage divider unit, which is connected to the output terminal of the isolated DC-DC chip and is used to adjust the magnitude of the negative power output.

[0011] Furthermore, at least one filter capacitor is connected in parallel to the output terminal of the isolated IGBT power module.

[0012] Furthermore, the power conversion module includes a linear voltage regulator chip, the input terminal of which is connected to an external power supply, and the output terminal of which is connected to the power supply terminal of the isolated IGBT driver module.

[0013] In summary, this application includes at least the following beneficial technical effects: The electrically isolated IGBT drive circuit provided in this application includes an isolated IGBT drive power supply module, an isolated IGBT drive module, and a power conversion module. The isolated IGBT drive power supply module is connected to an external power supply to provide isolated positive and negative power to the drive module. The isolated IGBT drive module is connected to an external controller to receive PWM signals. It uses the positive and negative power supplies and PWM signals to drive the external IGBT module to turn on / off, and determines the short circuit state by the level change of the detection terminal. Since each module has a clear division of labor and the isolation design reduces interference, the drive circuit structure is simple and highly reliable. It also has a built-in short circuit detection function, eliminating the need for additional circuits or equipment to monitor short circuit conditions, thus improving the overall performance of the circuit. Attached Figure Description

[0014] Figure 1 This is a structural block diagram of an electrically isolated IGBT drive circuit according to an embodiment of this application; Figure 2 This is a circuit diagram of an electrically isolated IGBT drive circuit according to an embodiment of this application. Detailed Implementation

[0015] The following embodiments will help those skilled in the art to further understand the function of this application, but do not limit this application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this application. These all fall within the protection scope of this application.

[0016] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0017] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0018] Example 1 This application provides an electrically isolated IGBT drive circuit, including an isolated IGBT power supply module, an isolated IGBT drive module, and a power conversion module. The isolated IGBT power supply module is connected to an external power source to generate isolated positive and negative power supplies, which are input to the isolated IGBT drive module. The power conversion module converts the external power supply into an operating voltage to power the isolated IGBT drive module. The isolated IGBT drive module is connected to an external controller to receive PWM signals. The isolated IGBT drive module drives the IGBT to turn on / off via the positive power supply, negative power supply, and PWM signals. The isolated IGBT drive module includes a detection terminal connected to the collector of the external IGBT module. The isolated IGBT drive module determines the short-circuit state by the level change at the detection terminal. Because each module has a clear function and the isolation design reduces interference, the drive circuit structure is simple and highly reliable. Furthermore, it has built-in short-circuit detection functionality, eliminating the need for additional circuitry or equipment to monitor short-circuit conditions, thus improving the overall circuit performance.

[0019] Specifically, the isolated IGBT power module includes an isolated DC-DC chip 1 and its peripheral circuitry. The peripheral circuitry mainly consists of an input filter circuit and an output filter circuit. The input filter circuit includes multiple filter capacitors connected in parallel to the input terminal of the isolated DC-DC chip 1, and the output filter circuit includes multiple filter capacitors connected in parallel to the output terminal of the isolated DC-DC chip (e.g., ...). Figure 2 The capacitors C3~C5 in the chip have a ripple-free effect. This isolated DC-DC chip can be of model R12C2T25 / R or TOP263 series. The chip integrates a high-frequency transformer to achieve electrical isolation.

[0020] In some embodiments, the isolated IGBT power module includes a first voltage divider unit connected to the output of the isolated DC-DC chip 1. This first voltage divider unit is used to adjust the magnitude of the output positive power supply. For example... Figure 2 As shown, the first voltage divider unit includes resistors R1 and R3. One end of resistor R1 is connected to pin 28 (positive power output terminal) of the isolated DC-DC chip 1. The other end of resistor R1 is connected to pin 34 of the isolated DC-DC chip 1 and one end of resistor R3. The other end of resistor R3 is connected to pin 19 (negative power output terminal) of the isolated DC-DC chip 1. The magnitude of the output positive power can be adjusted by adjusting the voltage division ratio of resistor R3 and resistor R1.

[0021] In some embodiments, the isolated IGBT power module includes a second voltage divider unit connected to the output of the isolated DC-DC chip 1. This second voltage divider unit is used to adjust the magnitude of the output negative power supply. For example... Figure 2 As shown, the second voltage divider unit includes resistors R4 and R5. One end of resistor R4 is connected to pin 19 (negative power output terminal) of the isolated DC-DC chip 1. The other end of resistor R4 is connected to pin 33 of the isolated DC-DC chip 1 and one end of resistor R5. The other end of resistor R5 is connected to pin 32 (reference ground terminal, connected to the emitter of the external IGBT module) of the isolated DC-DC chip 1. The magnitude of the output negative power supply can be adjusted by adjusting the voltage division ratio of resistors R5 and R4.

[0022] Specifically, the isolated IGBT driver module includes an IGBT driver chip 2, which can be an NCD57100 integrated circuit or a chip with the same function as the IXDN7E120I. Its pin 2 (detection terminal) is connected to the collector of the external IGBT module. When the voltage at the detection terminal exceeds 15V, the internal comparator of the chip is triggered, causing pin 13 to output a low-level alarm signal to the host controller.

[0023] Specifically, the power conversion module includes a linear regulator chip 3. The input terminal of the linear regulator chip 3 is connected to an external power supply, and the output terminal is connected to the power supply terminal of the IGBT driver chip 2. The linear regulator chip 3 can be an N7805-1C chip, or it can be replaced with a device of equivalent specification such as AMS1117-5.0. By utilizing the low dropout voltage characteristics of the linear chip, it can stably output a 5V / 1A operating power supply under a 15V input condition.

[0024] Example 2 This application provides an electrically isolated IGBT driver circuit, including an isolated IGBT power supply module, an isolated IGBT driver module, and a power conversion module. The isolated IGBT power supply module is connected to an external power source to generate isolated positive and negative power supplies, which are input to the isolated IGBT driver module. The power conversion module converts the external power supply into an operating voltage to power the isolated IGBT driver module. The isolated IGBT driver module is connected to an external controller to receive PWM signals. The isolated IGBT driver module drives the IGBT to turn on / off via the positive power supply, negative power supply, and PWM signals. The isolated IGBT driver module includes a detection terminal connected to the collector of an external IGBT module. The isolated IGBT driver module determines the short-circuit state by the level change at the detection terminal. Specifically, the isolated IGBT power supply module includes an isolated DC-DC chip 1 and its peripheral circuitry, the isolated IGBT driver module includes an IGBT driver chip 2, and the power conversion module includes a linear regulator chip 3.

[0025] Specifically, such as Figure 2 As shown, the isolated IGBT driver module includes a protection unit 4, which includes a resistor R7 and a diode D1. The detection terminal of the IGBT driver chip is connected to the anode of diode D1 via resistor R7, and the cathode of diode D1 is connected to the collector of the external IGBT module. The IGBT driver chip internally provides a constant current source I2. The voltage at pin 2 (detection terminal) of IGBT driver chip 2 is V2 = R7 * I2 + VD1 + VCE_IGBT. During normal operation, the voltage at the detection terminal will not exceed the threshold. When a short circuit occurs, the IGBT current becomes too large, causing VCE_IGBT to increase, making the voltage at pin 2 exceed the threshold. This causes the voltage at pin 13 of IGBT driver chip 2 to go low. This low-level signal is fed back to the upper controller, indicating a short circuit. Resistor R7 limits the current, preventing excessive current from flowing into the short-circuit detection terminal of the driver chip. Diode D1 can be a common rectifier diode, its function being to prevent reverse current.

[0026] In some embodiments, the protection unit 4 includes an overvoltage protection circuit, which comprises a Zener diode D2 and a capacitor C11. The detection terminal of the IGBT driver chip is connected to the cathode of the Zener diode D2, and the anode of the Zener diode D2 is connected to the emitter of an external IGBT module. The capacitor C11 is connected in parallel across the two ends of the Zener diode D2. The breakdown voltage of the overvoltage protection circuit is less than the maximum operating voltage of the IGBT driver chip. The Zener diode is used to limit the voltage at the short-circuit detection terminal to prevent excessive voltage from damaging the driver chip, while the capacitor C11 is used for filtering to reduce voltage fluctuations.

[0027] The electrically isolated IGBT drive circuit provided in this application includes an isolated IGBT drive power supply module, an isolated IGBT drive module, and a power conversion module. The isolated IGBT drive power supply module is connected to an external power supply to provide isolated positive and negative power to the drive module. The isolated IGBT drive module is connected to an external controller to receive PWM signals. It uses the positive and negative power supplies and PWM signals to drive the external IGBT module to turn on / off, and determines the short circuit state by the level change of the detection terminal. Since each module has a clear division of labor and the isolation design reduces interference, the drive circuit structure is simple and highly reliable. It also has a built-in short circuit detection function, eliminating the need for additional circuits or equipment to monitor short circuit conditions, thus improving the overall performance of the circuit.

[0028] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An electrically isolated IGBT drive circuit, characterized in that, The system includes an isolated IGBT power supply module, an isolated IGBT driver module, and a power conversion module. The isolated IGBT power supply module is connected to an external power source to generate isolated positive and negative power supplies, which are then input to the isolated IGBT driver module. The power conversion module converts the external power supply into an operating voltage to power the isolated IGBT driver module. The isolated IGBT driver module is connected to an external controller to receive PWM signals. The isolated IGBT driver module drives the IGBT to turn on / off via the positive and negative power supplies and the PWM signals. The isolated IGBT driver module also includes a detection terminal connected to the collector of an external IGBT module. The isolated IGBT driver module determines a short circuit state by detecting changes in the voltage level at the detection terminal.

2. The electrically isolated IGBT drive circuit according to claim 1, characterized in that, The isolated IGBT drive module includes an IGBT drive chip (2) and a protection unit (4). The protection unit (4) includes a resistor R7 and a diode D1. The detection terminal of the IGBT drive chip (2) is connected to the anode of the diode D1 through the resistor R7. The cathode of the diode D1 is connected to the collector of the external IGBT module. The IGBT drive chip (2) determines the short circuit state by the level change of the detection terminal.

3. The electrically isolated IGBT drive circuit according to claim 2, characterized in that, The protection unit (4) includes an overvoltage protection circuit, which includes a Zener diode D2 and a capacitor C11. The detection terminal of the IGBT driver chip (2) is connected to the cathode of the Zener diode D2, and the anode of the Zener diode D2 is connected to the emitter of the external IGBT module. The capacitor C11 is connected in parallel across the two ends of the Zener diode D2. The breakdown voltage of the overvoltage protection circuit is less than the maximum operating voltage of the IGBT driver chip (2).

4. The electrically isolated IGBT drive circuit according to claim 1, characterized in that, The isolated IGBT power module includes an isolated DC-DC chip (1).

5. The electrically isolated IGBT drive circuit according to claim 4, characterized in that, The isolated IGBT power module further includes a first voltage divider unit, which is connected to the output terminal of the isolated DC-DC chip (1) and is used to adjust the magnitude of the output positive power.

6. The electrically isolated IGBT drive circuit according to claim 4, characterized in that, The isolated IGBT power module also includes a second voltage divider unit, which is connected to the output terminal of the isolated DC-DC chip (1) and is used to adjust the magnitude of the negative power output.

7. The electrically isolated IGBT drive circuit according to claim 1, characterized in that, At least one filter capacitor is connected in parallel to the output terminal of the isolated IGBT power module.

8. The electrically isolated IGBT drive circuit according to claim 1, characterized in that, The power conversion module includes a linear voltage regulator chip (3), the input terminal of which is connected to an external power supply, and the output terminal of which is connected to the power supply terminal of the isolated IGBT driver module.

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