CN-121984485-A - IGBT drive protection circuit of integral form

CN121984485ACN 121984485 ACN121984485 ACN 121984485ACN-121984485-A

Abstract

An IGBT drive protection circuit in an integral form comprises a drive IC, an integral protection unit and a power module unit. The power module unit includes an IGBT and an FRD, and the integration protection unit includes an enabler, an integrator, a zero-crossing comparator, and a differentiator. The enabler receives the signal output by the drive IC and controls signal transmission to transmit a gate voltage signal to the integrator, the integrator integrates the gate voltage in real time, and the zero-crossing comparator detects whether the integrated value output by the integrator crosses zero. Under short circuit or abnormal working condition, the grid voltage rises slowly due to the increase of load impedance, and the integral value shows the characteristic of negative before positive. The zero crossing comparator detects the step signal of the integral value crossing zero, so that protection can be triggered before the IGBT enters the desaturation area, the response is rapid, the high-damage state of the IGBT which bears high voltage or high current for a long time is effectively avoided, and the failure risk of the device is obviously reduced.

Inventors

ZHAO HUAYONG
WANG XIN
WU RUI
CHEN XUEMIN

Assignees

浙江翠展微电子有限公司

Dates

Publication Date: 20260505
Application Date: 20251219

Claims (7)

1. An integrated IGBT drive protection circuit is characterized by comprising a drive IC, an integrated protection unit connected with the drive IC, and a power module unit connected with the integrated protection unit, wherein the power module unit comprises an IGBT and an FRD, the integrated protection unit comprises an enabler connected with the drive IC and the power module unit, an integrator connected with the enabler, an zero-crossing comparator connected with the integrator, and a differentiator connected with the zero-crossing comparator and the drive IC, the enabler receives a signal output by the drive IC and controls signal transmission to transmit a gate voltage signal to the integrator, the integrator integrates the gate voltage in real time, the zero-crossing comparator detects whether the integrated value output by the integrator crosses zero, the zero-crossing comparator outputs a step signal when the integrated value changes from a negative value to a positive value, the step signal is output by the zero-crossing comparator, and the step comparator performs a pulse triggering operation to the drive IC.
2. The IGBT drive protection circuit according to claim 1, wherein the enabler comprises a resistor R01 and an NMOS transistor Q1, one end of the resistor R01 is connected with the drive IC, the other end is connected with the grid electrode of the NMOS transistor Q1, the drain electrode of the NMOS transistor Q1 is connected with the grid electrode of the IGBT, and the source electrode of the NMOS transistor Q1 is connected with the input end of the integrator.
3. The IGBT drive protection circuit according to claim 2, wherein the integrator comprises a resistor R11, a capacitor C11, a resistor R12, a first operational amplifier, and a resistor R13, wherein one end of the resistor R11 is connected with the source of the NMOS transistor Q1, the other end of the resistor R11 is connected with the input end of the first operational amplifier, one end of the capacitor C11 is connected with the input end of the first operational amplifier, the other end of the capacitor C11 is connected with the output end of the first operational amplifier, one end of the resistor R12 is connected with the reference end of the first operational amplifier, the other end of the resistor R12 is grounded, and the output end of the first operational amplifier is connected with the zero-crossing comparator.
4. The IGBT drive protection circuit as recited in claim 3, wherein said integrator further comprises a resistor R13, said resistor R13 being connected in parallel across said capacitor C11 and providing a discharge path.
5. The IGBT drive protection circuit of claim 3, wherein an input of said zero-crossing comparator is connected to an output of said first operational amplifier and is configured to receive an integrated value signal, a reference terminal of said zero-crossing comparator is connected to 0V, and an output of said zero-crossing comparator is connected to said differentiator.
6. The IGBT drive protection circuit according to claim 1, wherein the differentiator comprises a resistor R31, a capacitor C31 and a second operational amplifier, one end of the capacitor C31 is connected with the output end of the zero-crossing comparator, the other end of the capacitor C31 is connected with the input end of the second operational amplifier, one end of the resistor R31 is connected with the input end of the second operational amplifier, the other end is connected with the output end of the second operational amplifier, the reference end of the second operational amplifier is connected with 0V ground, and the output end of the second operational amplifier is connected with the drive IC.
7. The IGBT drive protection circuit of claim 1, further comprising a protection unit connected to the drive IC, wherein the protection unit is configured to protect a critical node of the power module unit.

Description

IGBT drive protection circuit of integral form Technical Field The invention relates to the technical field of power module protection circuits, in particular to an IGBT driving protection circuit in an integral form. Background IGBT (insulated Gate Bipolar transistor) is used as core power device in power electronic system, and is widely applied in frequency converter, inverter, new energy automobile, new energy power generation, etc., and its performance directly affects system reliability and efficiency. The safe operation of the IGBT depends on the accurate control of the driving circuit to the grid signal and the rapid protection to the abnormal working condition. When the current of the IGBT is abnormally increased due to load short circuit, overcurrent or other faults, if the driving protection circuit fails to respond in time, the device can be subjected to irreversible damage such as over-temperature, breakdown and the like due to long-time bearing of high voltage and large current, and even system-level faults are caused. At present, the driving protection of an IGBT power module is multiple, miller clamp protection is used for opening parasitic opening, active clamp protection is used for voltage spike, corresponding protection operation is carried out only when a device enters a desaturation area for short circuit desaturation detection protection, the IGBT voltage is lower during normal conduction, when short circuit or abnormality occurs, the IGBT enters a desaturation state due to current rapid rise, the current is always 5-8 times of rated current, the IGBT voltage is very high, instantaneous power is extremely high, and irreversible damage to the IGBT can be generated. In the prior art, the change of the voltage is monitored mostly, and when the voltage exceeds a set threshold value after the device is detected to enter desaturation, a protection signal is triggered to turn off the gate drive, so that the device is prevented from being continuously damaged. However, the method has certain response hysteresis, the desaturation phenomenon is a result after the IGBT is failed, but is not an early signal, the IGBT can only act when a device enters a desaturation area protection circuit, and the IGBT generates extremely high instantaneous power when desaturation, and has high stress impact during the period, the reaction speed is low, so that irreversible damage is caused. Disclosure of Invention In view of the above, the present invention provides an integrated IGBT driving protection circuit to solve the above technical problems. An IGBT drive protection circuit of an integral form, comprising a drive IC, an integral protection unit connected to the drive IC, and a power module unit connected to the integral protection unit, the power module unit including an IGBT and an FRD, the integral protection unit including an enabler connected to the drive IC and the power module unit, an integrator connected to the enabler, a zero-crossing comparator connected to the integrator, and a differentiator connected to the zero-crossing comparator and the drive IC, the enabler receiving a signal output from the drive IC and controlling signal transmission to transmit a gate voltage signal to the integrator, the integrator integrating a gate voltage in real time, the zero-crossing comparator detecting whether the integrated value output from the integrator crosses a zero point, the zero-crossing comparator outputting a step signal when the value changes from a zero crossing point to a positive value, the differentiator converting the step signal to a pulse signal, the protection operation being performed by the drive IC. Further, the enabler includes a resistor R01, and an NMOS tube Q1, one end of the resistor R01 is connected with the driving IC, the other end is connected with the gate of the NMOS tube Q1, the drain of the NMOS tube Q1 is connected with the gate of the IGBT, and the source of the NMOS tube Q1 is connected with the input end of the integrator. Further, the integrator comprises a resistor R11, a capacitor C11, a resistor R12, a first operational amplifier, and a resistor R13, wherein one end of the resistor R11 is connected with the source of the NMOS transistor Q1, the other end of the resistor R11 is connected with the input end of the first operational amplifier, one end of the capacitor C11 is connected with the input end of the first operational amplifier, the other end of the capacitor C11 is connected with the output end of the first operational amplifier, one end of the resistor R12 is connected with the reference end of the first operational amplifier, the other end of the resistor is grounded, and the output end of the first operational amplifier is connected with the zero-crossing comparator. Further, the integrator further includes a resistor R13, where the resistor R13 is connected in parallel across the capacitor C11 and is used to provide a discharge path. Further, an input end