An IGBT control circuit, method, PCB board and controller

Abstract

This invention discloses an IGBT control circuit, method, PCB board, and controller, including a main control unit, a driving resistor unit, a resistor adjustment unit, an IGBT transistor U1, and a voltage sampling unit. The driving terminal of the main control unit is connected to one end of the driving resistor unit, the other end of the driving resistor unit is connected to the resistor adjustment unit, the other end of the resistor adjustment unit is connected to the gate of the IGBT transistor U1, the emitter of the IGBT transistor U1 is grounded, the collector of the IGBT transistor U1 is connected to the input terminal of the voltage sampling unit, the output terminal of the voltage sampling unit is connected to the input terminal of the main control unit, and the feedback control terminal of the main control unit is connected to the resistor adjustment unit. The main control unit controls the operating state of the resistor adjustment unit connected to the driving resistor unit according to the feedback signal from the voltage sampling unit; it adaptively adjusts according to the actual operating state of the IGBT to improve voltage overshoot and current spike problems during switching.

Description

Technical Field

[0001] This invention relates to the field of IGBT transistor technology, and in particular to an IGBT control circuit, method, PCB board and controller. Background Technology

[0002] Traditional Insulated Gate Bipolar Transistor (IGBT) control circuits typically employ a diode scheme in the drive circuit, setting different fixed resistor values ​​for the turn-on and turn-off paths (e.g., using diodes connected in parallel in reverse). While this scheme can initially distinguish between the turn-on and turn-off states, its control logic is rigid and has certain limitations. Specifically: First, the control dimension is singular, only able to distinguish between the two macroscopic states of "turn-on" and "turn-off," making it difficult to implement differentiated control for different physical stages (such as the current decline period and voltage rise period) within a single switching event (such as a turn-off process); Second, the timing control is passive, with its switching speed entirely dependent on the polarity change of the drive voltage, passively determined by the unidirectional conductivity of the diode.

[0003] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an IGBT control circuit that adaptively adjusts according to the actual operating state of the IGBT to improve the problems of voltage overshoot and current spike during the switching process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An IGBT control circuit includes a main control unit, a driving resistor unit, a resistor adjustment unit, an IGBT transistor U1, and a voltage sampling unit. The driving terminal of the main control unit is connected to one end of the driving resistor unit, the other end of the driving resistor unit is connected to the resistor adjustment unit, the other end of the resistor adjustment unit is connected to the gate of the IGBT transistor U1, the emitter of the IGBT transistor U1 is grounded, the collector of the IGBT transistor U1 is connected to the input terminal of the voltage sampling unit, the output terminal of the voltage sampling unit is connected to the input terminal of the main control unit, and the feedback control terminal of the main control unit is connected to the resistor adjustment unit. The main control unit is used to control the operating state of the resistor adjustment unit connected to the driving resistor unit according to the feedback signal from the voltage sampling unit.

[0006] In the IGBT control circuit, the driving resistor unit includes a first resistor R1; the resistor adjustment unit includes a second resistor R2 and a switching unit; the driving terminal of the main control unit is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to the gate of the IGBT transistor U1, the input terminal and the output terminal of the switching unit are respectively connected to the two ends of the second resistor R2, and the enable terminal of the switching unit is connected to the feedback control terminal of the main control unit.

[0007] In the IGBT control circuit, the voltage sampling unit includes a voltage sampling section and a voltage comparator U2. The input terminal of the voltage sampling section is connected to the collector of the IGBT transistor U1, the output terminal of the voltage sampling section is connected to the non-inverting input terminal of the voltage comparator U2, the inverting input terminal of the voltage comparator U2 is connected to an external reference voltage terminal, and the output terminal of the voltage comparator U2 is connected to the input terminal of the main control unit.

[0008] In the IGBT control circuit, the voltage sampling section includes a third resistor R3, a fourth resistor R4, and a first capacitor C1. One end of the fourth resistor R4 and one end of the first capacitor C1 are respectively connected to the collector of the IGBT transistor U1. The other end of the fourth resistor R4 is connected to an external power supply. The non-inverting input of the voltage comparator U2 is connected to the other end of the first capacitor C1 and one end of the third resistor R3. The other end of the third resistor R3 is grounded.

[0009] This application also provides an IGBT control circuit for operating control of the IGBT control circuit described above; the IGBT control method includes: when the IGBT transistor U1 is turned on, the main control unit controls the resistor adjustment unit to enter the resistance value access state, increases the resistance value of the driving resistor unit, so that the IGBT transistor U1 enters the slow turn-on stage, and sends a conduction signal to the driving resistor unit through the main control unit; the output voltage of the IGBT transistor U1 is obtained through the voltage sampling unit, and when the output voltage reaches a preset rise threshold, the main control unit controls the resistor adjustment unit to enter the short-circuit state, decreases the resistance value of the driving resistor unit, so that the IGBT transistor U1 enters the fast turn-on stage.

[0010] The IGBT control method further includes: when the IGBT transistor U1 is turned off, the main control unit controls the resistor adjustment unit to enter a short-circuit state, reducing the resistance value of the driving resistor unit so that the IGBT transistor U1 enters the fast turn-off stage, and sends a cutoff signal to the driving resistor unit through the main control unit; the output voltage of the IGBT transistor U1 is obtained through the voltage sampling unit, and when the output voltage reaches a preset drop threshold, the main control unit controls the resistor adjustment unit to enter a resistance value input state, increasing the resistance value of the driving resistor unit so that the IGBT transistor U1 enters the slow turn-off stage.

[0011] In the IGBT control method, after obtaining the output voltage of IGBT transistor U1 through the voltage sampling unit, the method further includes: calculating the slow rise rate based on the output voltage of IGBT transistor U1 during the slow turn-on phase; obtaining the adjusted output voltage of IGBT transistor U1 through the voltage sampling unit, calculating the adjusted rise rate based on the adjusted output voltage; if the adjusted rise rate is less than or equal to the slow rise rate, controlling the main control unit to output a first abnormal signal; the first abnormal signal is a short circuit signal of the resistor adjustment unit.

[0012] In the IGBT control method, after obtaining the output voltage of IGBT transistor U1 through the voltage sampling unit, the method further includes: when the output voltage sampled by the voltage sampling unit is in a no-signal state, controlling the main control unit to output a second abnormal signal; the second abnormal signal is a signal indicating that the resistor adjustment unit is open-circuited.

[0013] This application also provides a PCB board on which the IGBT control circuit described above is printed.

[0014] This application also provides a controller, which uses the IGBT control circuit described above for operation control.

[0015] Beneficial effects: This invention provides an IGBT control circuit that dynamically adjusts the drive resistor based on real-time output voltage feedback. This allows for differentiated control of different physical stages within the switching process by applying varying drive strengths according to different voltage changes during a single switching event. This helps guide the switching trajectory to a more ideal range. Secondly, the main control unit determines the state switching point based on actively monitored voltage signals and actively controls the resistor adjustment unit, making the switching speed timing more precise and controllable, reducing reliance on passive responses to device parasitic parameters. The circuit can adaptively adjust according to the actual operating state of the IGBT, improving voltage overshoot and current spikes during switching, reducing switching losses and electromagnetic interference levels, and enhancing the accuracy of drive control and the reliability of the circuit operation. Attached Figure Description

[0016] Figure 1 A circuit block diagram of the IGBT control circuit provided by the present invention; Figure 2 The circuit structure diagram of the IGBT control circuit provided by the present invention.

[0017] Explanation of key component symbols: 1-Main control unit, 2-Drive resistor unit, 3-Resistor adjustment unit, 4-Voltage sampling unit. Detailed Implementation

[0018] This invention provides an IGBT control circuit, method, PCB board, and controller. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0019] In the description of this invention, it should be understood that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0020] Please see Figures 1 to 2 This invention provides an IGBT control circuit, including a main control unit 1, a driving resistor unit 2, a resistance adjustment unit 3, an IGBT transistor U1, and a voltage sampling unit 4. The driving terminal of the main control unit 1 is connected to one end of the driving resistor unit 2, the other end of the driving resistor unit 2 is connected to the resistance adjustment unit 3, and the other end of the resistance adjustment unit 3 is connected to the gate of the IGBT transistor U1. The emitter of the IGBT transistor U1 is grounded, and its collector is connected to the input terminal of the voltage sampling unit 4. The output terminal of the voltage sampling unit 4 is connected to the input terminal of the main control unit 1, and the feedback control terminal of the main control unit 1 is connected to the resistance adjustment unit 3. The main control unit 1 controls the operating state of the resistance adjustment unit 3 connected to the driving resistor unit 2 according to the feedback signal from the voltage sampling unit 4, thereby dynamically adjusting the equivalent resistance of the drive circuit.

[0021] In this embodiment, in terms of control, it overcomes the limitation of traditional solutions that can only coarsely distinguish between two macroscopic states: on and off. By dynamically adjusting the drive resistor based on real-time output voltage feedback, this circuit can apply different drive intensities according to different stages of voltage change (such as the current decline period and the voltage rise period) within a single switching event (e.g., the turn-off process), achieving differentiated control of different physical stages within the switching process. This helps guide the switching trajectory to a more ideal range. Secondly, in terms of timing control, it changes the traditional approach of passively switching based on changes in drive voltage polarity and diode characteristics. This circuit uses the main control unit 1 to determine the state switching point based on actively monitored voltage signals and actively controls the action of the resistor adjustment unit 3, thereby making the switching timing of the switching speed more precise and controllable, reducing the dependence on passive responses to device parasitic parameters. This circuit structure can adaptively adjust according to the actual operating state of the IGBT, improving the problems of voltage overshoot and current spikes during the switching process, which helps reduce switching losses and electromagnetic interference levels, and improves the accuracy of drive control and the reliability of circuit operation.

[0022] The working principle of this application is as follows: The voltage sampling unit 4 acquires the output voltage signal of the collector of IGBT transistor U1 in real time and feeds it back to the main control unit 1. Based on the preset control logic and the received feedback signal, the main control unit 1 sends a control command to the resistor adjustment unit 3 to change the operating state of the resistor adjustment unit 3 connected to the drive resistor unit 2. Specifically, when the feedback signal indicates that the output voltage of IGBT transistor U1 reaches a certain preset threshold, the main control unit 1 operates the resistor adjustment unit 3 through its feedback control terminal, switching it between "connected" and "short-circuited" states. The change in the operating state of the resistor adjustment unit 3 directly determines its total equivalent resistance value after being connected in series with the drive resistor unit 2. This equivalent resistance is connected between the drive terminal of the main control unit 1 and the gate of IGBT transistor U1, forming the impedance of the drive circuit. The dynamic change in the equivalent resistance value of the drive circuit adjusts the magnitude of the drive current flowing to or out of the gate of IGBT transistor U1, thereby controlling the charging and discharging rate of the gate capacitor, ultimately achieving active regulation of the slope of voltage and current changes during the turn-on and turn-off processes of IGBT transistor U1.

[0023] Further, in one embodiment of the present invention, the driving resistor unit 2 includes a first resistor R1. The resistor adjustment unit 3 includes a second resistor R2 and a switching unit. The driving terminal of the main control unit 1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the gate of the IGBT transistor U1. The input and output terminals of the switching unit are respectively connected to the two ends of the second resistor R2, and the enable terminal of the switching unit is connected to the feedback control terminal of the main control unit 1. When the main control unit 1 enables the switching unit through the feedback control terminal, the switching unit is turned on, shorting the second resistor R2. At this time, the equivalent resistance of the driving circuit is approximately the resistance value of the first resistor R1. When the main control unit 1 controls the switching unit to turn off, the second resistor R2 is connected to the circuit. At this time, the equivalent resistance of the driving circuit is the sum of the resistance values ​​of the first resistor R1 and the second resistor R2. By controlling the state of the switching unit, the equivalent resistance of the driving circuit can be adjusted.

[0024] Furthermore, in one embodiment of the present invention, the specific implementation of the switching unit can be various electronic switching devices with controlled on / off functions. For example, the switching unit can be an N-channel field-effect transistor (MOSFET) Q1. In this specific connection, the drain and source of the MOSFET Q1 are respectively connected to the two ends of the second resistor R2, and its gate serves as the enable terminal of the switching unit, connected to the feedback control terminal of the main control unit 1. When the main control unit 1 needs to short-circuit the second resistor R2, its feedback control terminal outputs a driving voltage (such as a high level) sufficient to fully turn on the MOSFET Q1. At this time, the drain-source of the MOSFET Q1 presents a low-resistance state, which is equivalent to connecting the two ends of the second resistor R2, thus bypassing it. When the main control unit 1 needs to connect the second resistor R2, its feedback control terminal outputs a voltage (such as a low level or zero potential) to turn off the MOSFET Q1. At this time, the drain-source of the MOSFET Q1 presents a high-resistance state, and the second resistor R2 is normally connected in series in the driving circuit. To ensure the speed and reliability of the switching action, a small resistor can be connected in series with the gate of the field-effect transistor Q1, and a resistor can be connected in parallel between its gate and source to improve the switching characteristics and prevent electrostatic damage. The switching action is not limited to field-effect transistors; it can also be constructed using bipolar transistors, insulated-gate bipolar transistors, or optocouplers, along with appropriate drive circuits. Its function is to respond to the control signals of the main control unit 1 and controllably determine whether the second resistor R2 is short-circuited in parallel.

[0025] Further, in one embodiment of the present invention, the voltage sampling unit 4 is used to acquire the output voltage of the collector of the IGBT transistor U1 and feed it back to the main control unit 1. In this embodiment, the voltage sampling unit 4 includes a voltage sampling section and a voltage comparator U2. The input terminal of the voltage sampling section is connected to the collector of the IGBT transistor U1, and the output terminal of the voltage sampling section is connected to the non-inverting input terminal of the voltage comparator U2. The inverting input terminal of the voltage comparator U2 is connected to a port that provides an external reference voltage, and its output terminal is connected to the input terminal of the main control unit 1. The input terminal of the voltage sampling section is directly or through a voltage divider network connected to the collector of the IGBT transistor U1 to sense the high voltage signal that changes over time at that point. After possible attenuation, filtering, and other conditioning within the voltage sampling section, the high voltage signal is converted into a sampling signal with an amplitude suitable for subsequent circuit processing that can reflect the instantaneous change of the collector voltage, and is output to the non-inverting input terminal of the voltage comparator U2. The inverting input terminal of the voltage comparator U2 is connected to a port that provides a stable external reference voltage, the value of which corresponds to a preset voltage switching threshold in the control logic. Voltage comparator U2 compares the sampled signal at its non-inverting input with a fixed reference voltage at its inverting input in real time. When the sampled signal level is higher than the reference voltage, the output of voltage comparator U2 outputs a logic state (e.g., high level); when the sampled signal level is lower than the reference voltage, it outputs the opposite logic state (e.g., low level). The output of voltage comparator U2 is directly connected to the input of main control unit 1. Therefore, its high and low level output signals constitute a clear digital feedback signal, which is read by main control unit 1 in real time. In this way, the analog, continuously changing collector voltage is converted into a discrete digital logic signal, and main control unit 1 can directly and quickly determine whether the collector voltage has crossed a preset threshold point without analog-to-digital conversion.

[0026] To ensure stable voltage sampling and comparison, the voltage sampling section includes a third resistor R3, a fourth resistor R4, and a first capacitor C1. One end of the fourth resistor R4 and one end of the first capacitor C1 are both connected to the collector of the IGBT transistor U1, and the other end of the fourth resistor R4 is connected to an external power supply for pull-up. The non-inverting input of the voltage comparator U2 is connected to the other end of the first capacitor C1 and one end of the third resistor R3, and the other end of the third resistor R3 is grounded. The first capacitor C1 and the third resistor R3 can form a simple filter circuit, which helps to smooth the sampling signal, while the fourth resistor R4 provides pull-up bias. The voltage comparator U2 compares the sampled voltage with an external reference voltage and outputs the comparison result to the main control unit 1 in the form of high and low levels, as the basis for determining whether the collector voltage of the IGBT transistor U1 has reached a preset threshold.

[0027] It should be noted that the main control unit 1 can be a microcontroller unit (MCU), digital signal processor (DSP), or application-specific integrated circuit (ASIC) that integrates logic operations, signal generation, and input / output interfaces. The main control unit 1 includes at least one drive signal output terminal (i.e., the drive terminal), one or more feedback signal input terminals (i.e., the input terminals), and at least one control signal output terminal (i.e., the feedback control terminal). Internally, it implements a preset control strategy through a fixed program or hardware logic. During operation, the drive terminal of the main control unit 1 generates a PWM (pulse width modulation) signal or level signal to drive the IGBT transistor U1 to turn on or off. This signal is sent to the gate of the IGBT transistor U1 via the drive resistor unit 2 and the resistor adjustment unit 3. Simultaneously, the input terminal of the main control unit 1 continuously receives feedback signals from the voltage sampling unit 4 (e.g., the output of the voltage comparator U2), which characterizes the comparison result between the collector voltage of the IGBT transistor U1 and a preset threshold. The internal logic of the main control unit 1 determines the operating stage of the IGBT transistor U1 based on the current operation command (e.g., turn on or turn off) and the real-time feedback signal. When the feedback signal indicates that the collector voltage has reached a preset rising or falling threshold, the logic of the main control unit 1 determines that the drive speed needs to be switched. It then sends a corresponding control command (such as high / low level switching) to the switching section through its feedback control terminal, thereby changing the state of the resistance adjustment unit 3 and achieving dynamic adjustment of the equivalent resistance of the drive circuit. To ensure stable signal transmission between the main control unit 1 and the power circuit, level conversion, isolation, and drive enhancement circuits can be integrated or externally connected as needed in the connections between the drive terminal, input terminal, feedback control terminal, and external circuits. The main control unit 1 may also include fault diagnosis logic, such as the aforementioned judgment of abnormal rates, and can output the first abnormal signal or the second abnormal signal through additional communication or alarm pins.

[0028] This application also provides an IGBT control method, which is used to control the operation of the IGBT control circuit described above, one embodiment of which includes: 101. When the IGBT transistor U1 is turned on, the main control unit 1 controls the resistor adjustment unit 3 to enter the resistance value input state, increases the resistance value of the drive resistor unit 2, so that the IGBT transistor U1 enters the slow turn-on stage, and sends a conduction signal to the drive resistor unit 2 through the main control unit 1. 102. The output voltage of IGBT transistor U1 is obtained through voltage sampling unit 4. When the output voltage reaches the preset rising threshold, the main control unit 1 controls the resistor adjustment unit 3 to enter the short-circuit state and reduces the resistance value of the drive resistor unit 2 so that IGBT transistor U1 enters the fast turn-on stage.

[0029] In this embodiment, when the IGBT transistor U1 needs to be turned on, the main control unit 1 first controls the resistor adjustment unit 3 to enter the resistance connection state, that is, controls the switch to turn off, so that the second resistor R2 is connected to the drive circuit, thereby increasing the equivalent resistance of the drive circuit. Subsequently, the main control unit 1 sends a conduction signal (such as a high-level pulse) to the drive resistor unit 2. Since the drive resistance is large at this time, the gate charge accumulation speed of the IGBT transistor U1 is relatively slow, causing it to enter a slow turn-on stage, and its collector voltage drops smoothly. At the same time, the voltage sampling unit 4 continuously acquires the output voltage of the collector of the IGBT transistor U1. When the output voltage drops to the preset rising threshold voltage (this threshold corresponds to the voltage point of the switching speed during the turn-on process), the output state of the voltage comparator U2 flips, and the main control unit 1 receives this feedback signal. The main control unit 1 then controls the resistor adjustment unit 3 to enter the short-circuit state, that is, controls the switch to turn on, short-circuiting the second resistor R2, thereby reducing the equivalent resistance of the drive circuit. At this time, the drive circuit resistance becomes smaller, the gate driving capability is enhanced, and the IGBT transistor U1 enters the fast turn-on stage, quickly completing the remaining turn-on process. This slow-then-fast activation strategy helps reduce voltage overshoot during the activation process.

[0030] In a second embodiment of the diode surge current testing method of the present invention, the method further includes: 201. When the IGBT transistor U1 is turned off, the main control unit 1 controls the resistor adjustment unit 3 to enter the short-circuit state, reduces the resistance value of the drive resistor unit 2, so that the IGBT transistor U1 enters the fast turn-off stage, and sends a cut-off signal to the drive resistor unit 2 through the main control unit 1. 202. The output voltage of IGBT transistor U1 is obtained through voltage sampling unit 4. When the output voltage reaches the preset drop threshold, the main control unit 1 controls the resistor adjustment unit 3 to enter the resistance value access state, and increases the resistance value of the drive resistor unit 2 so that IGBT transistor U1 enters the slow turn-off stage.

[0031] In this embodiment, when it is necessary to turn off the IGBT transistor U1, the main control unit 1 first controls the resistor adjustment unit 3 to enter a short-circuit state, that is, to keep or control the switching part to be on, so that the equivalent resistance of the drive circuit is a small value. Subsequently, the main control unit 1 sends a cutoff signal (such as a low level or negative voltage pulse) to the drive resistor unit 2. Due to the small drive resistance, the gate charge of the IGBT transistor U1 is quickly drawn away, causing it to enter a fast turn-off stage, and its collector current drops rapidly. At the same time, the voltage sampling unit 4 continuously monitors the collector voltage. When the collector voltage rises to the preset drop threshold voltage (this threshold corresponds to the voltage point of the switching speed during the turn-off process), the output state of the voltage comparator U2 flips again, and the main control unit 1 receives this feedback signal. The main control unit 1 then controls the resistor adjustment unit 3 to enter a resistance value connection state, that is, to control the switching part to be turned off, and connects the second resistor R2 into the circuit, thereby increasing the equivalent resistance of the drive circuit. At this time, the IGBT transistor U1 enters a slow turn-off stage, and the rise rate of its collector voltage becomes gradual. This fast-then-slow turn-off strategy helps suppress voltage spikes during the turn-off process.

[0032] In a third embodiment of the diode surge current testing method of the present invention, after step 102, the method further includes: 301. The slow rise rate is calculated based on the output voltage of IGBT transistor U1 during the slow turn-on phase. 302. The voltage sampling unit 4 obtains the adjusted output voltage of IGBT transistor U1, and calculates the adjustment rise rate based on the adjusted output voltage. If the adjustment rise rate is less than or equal to the slow rise rate, the main control unit 1 outputs the first abnormal signal. The first abnormal signal is the signal of short circuit of resistor adjustment unit 3.

[0033] In this embodiment, to improve circuit reliability, the control method may further include a fault detection function. During the turn-on process, when the circuit enters the slow turn-on stage, the main control unit 1 can calculate and store the slow voltage rise rate (actually the absolute value of the fall rate) of this stage based on the output voltage of the IGBT transistor U1 obtained by the voltage sampling unit 4. After the control resistor adjustment unit 3 switches to the short-circuit state and enters the fast turn-on stage, the main control unit 1 continues to obtain the adjusted output voltage through the voltage sampling unit 4 and calculate the adjusted voltage rise rate. If the calculation finds that the adjusted rise rate is less than or equal to the previously stored slow rise rate, it indicates that the equivalent resistance of the drive circuit has not decreased as expected. The main control unit 1 can then determine that the resistor adjustment unit 3 may have a short-circuit fault (e.g., the switch section has failed to conduct normally) and output the corresponding first abnormal signal.

[0034] In the fourth embodiment of the diode surge current testing method of the present invention, after step 102, the method further includes: 401. When the output voltage sampled by the voltage sampling unit 4 is in a no-signal state, the main control unit 1 is controlled to output a second abnormal signal; the second abnormal signal is the signal that the resistor adjustment unit 3 is open-circuited.

[0035] In this embodiment, if the output voltage sampled by the voltage sampling unit 4 remains in a no-signal state (for example, the output of the voltage comparator U2 remains constant, or the sampled voltage is always abnormal), the main control unit 1 can determine that there is a fault such as an open circuit in the sampling link or the resistor adjustment unit 3, and output a second abnormal signal. These abnormal signals can be used to trigger system protection or alarms.

[0036] This application also provides a PCB board on which the IGBT control circuit described above is printed.

[0037] This application also provides a controller, which uses the IGBT control circuit described above for operation control.

[0038] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. An IGBT control circuit, characterized in that, The system includes a main control unit, a driving resistor unit, a resistor adjustment unit, an IGBT transistor U1, and a voltage sampling unit. The driving terminal of the main control unit is connected to one end of the driving resistor unit, the other end of the driving resistor unit is connected to the resistor adjustment unit, the other end of the resistor adjustment unit is connected to the gate of the IGBT transistor U1, the emitter of the IGBT transistor U1 is grounded, the collector of the IGBT transistor U1 is connected to the input terminal of the voltage sampling unit, the output terminal of the voltage sampling unit is connected to the input terminal of the main control unit, and the feedback control terminal of the main control unit is connected to the resistor adjustment unit. The main control unit controls the operating state of the resistor adjustment unit connected to the driving resistor unit based on the feedback signal from the voltage sampling unit.

2. The IGBT control circuit according to claim 1, characterized in that, The driving resistor unit includes a first resistor R1; the resistor adjustment unit includes a second resistor R2 and a switching unit; the driving terminal of the main control unit is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to the gate of the IGBT transistor U1, the input terminal and the output terminal of the switching unit are respectively connected to the two ends of the second resistor R2, and the enable terminal of the switching unit is connected to the feedback control terminal of the main control unit.

3. The IGBT control circuit according to claim 1, characterized in that, The voltage sampling unit includes a voltage sampling section and a voltage comparator U2. The input terminal of the voltage sampling section is connected to the collector of the IGBT transistor U1, the output terminal of the voltage sampling section is connected to the non-inverting input terminal of the voltage comparator U2, the inverting input terminal of the voltage comparator U2 is connected to an external reference voltage terminal, and the output terminal of the voltage comparator U2 is connected to the input terminal of the main control unit.

4. The IGBT control circuit according to claim 3, characterized in that, The voltage sampling section includes a third resistor R3, a fourth resistor R4, and a first capacitor C1. One end of the fourth resistor R4 and one end of the first capacitor C1 are respectively connected to the collector of the IGBT transistor U1. The other end of the fourth resistor R4 is connected to an external power supply. The non-inverting input of the voltage comparator U2 is connected to the other end of the first capacitor C1 and one end of the third resistor R3. The other end of the third resistor R3 is grounded.

5. An IGBT control method, characterized in that, The IGBT control method is used to control the operation of the IGBT control circuit as described in any one of claims 1-4; the IGBT control method includes: When IGBT transistor U1 is turned on, the main control unit controls the resistor adjustment unit to enter the resistance value input state, increases the resistance value of the drive resistor unit, so that IGBT transistor U1 enters the slow turn-on stage, and sends a turn-on signal to the drive resistor unit through the main control unit. The output voltage of IGBT transistor U1 is obtained by the voltage sampling unit. When the output voltage reaches the preset rising threshold, the main control unit controls the resistor adjustment unit to enter the short-circuit state, reducing the resistance value of the drive resistor unit so that IGBT transistor U1 enters the fast turn-on stage.

6. The IGBT control method according to claim 5, characterized in that, Also includes: When the IGBT transistor U1 is turned off, the main control unit controls the resistor adjustment unit to enter the short-circuit state, reduces the resistance value of the drive resistor unit, so that the IGBT transistor U1 enters the fast turn-off stage, and sends a cut-off signal to the drive resistor unit through the main control unit. The output voltage of IGBT transistor U1 is obtained by the voltage sampling unit. When the output voltage reaches the preset drop threshold, the main control unit controls the resistor adjustment unit to enter the resistance value input state, increasing the resistance value of the drive resistor unit so that IGBT transistor U1 enters the slow turn-off stage.

7. The IGBT control method according to claim 5, characterized in that, After obtaining the output voltage of IGBT transistor U1 through the voltage sampling unit, the method further includes: The slow rise rate is calculated based on the output voltage of IGBT transistor U1 during the slow turn-on phase. The voltage sampling unit obtains the adjusted output voltage of IGBT transistor U1, and calculates the adjustment rise rate based on the adjusted output voltage. If the adjustment rise rate is less than or equal to the slow rise rate, the main control unit outputs a first abnormal signal; the first abnormal signal is a short circuit signal of the resistor adjustment unit.

8. The IGBT control method according to claim 5, characterized in that, After obtaining the output voltage of IGBT transistor U1 through the voltage sampling unit, the method further includes: When the output voltage sampled by the voltage sampling unit is in a no-signal state, the main control unit outputs a second abnormal signal; the second abnormal signal is the signal that the resistor adjustment unit is open-circuited.

9. A PCB board, characterized in that, The PCB board is printed with the IGBT control circuit as described in any one of claims 1-4.

10. A controller board, characterized in that, The controller uses the IGBT control circuit as described in any one of claims 1-4 for operation control.

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