IGBT (Insulated Gate Bipolar Translator) soft turn-off circuit with low peak voltage

Abstract

The utility model discloses an IGBT (Insulated Gate Bipolar Translator) soft turn-off circuit with low peak voltage, which comprises a controller, an amplification module, a first resistor, a second resistor, a first transistor, a second transistor, a third resistor, a fourth resistor, a first capacitor, an IGBT device, a fifth resistor, a first triode, a sixth resistor, a seventh resistor, an eighth resistor, a second capacitor, a voltage-regulator tube and a second triode, through the above mode, the current flowing through the IGBT device can be reduced, the short-circuit fault of the controller can be avoided, and the short-circuit current flowing through the IGBT device can be reduced to a relatively small state under a short-circuit working condition, so that hard turn-off of the IGBT device under the condition of a small conduction current can be realized, the turn-off peak voltage of the IGBT device can be reduced to a small level, and the reliability of the IGBT device can be improved. Damage to the IGBT device is avoided, and the service life of the rail transit equipment is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of IGBT devices, in particular to an IGBT soft shut-off circuit with a low peak voltage. Background Art

[0002] The high-power electronic devices of rail transit equipment, especially IGBT devices, will generate large voltage spikes when they are directly turned off, which will harm the IGBT devices themselves. Figure 1 The conventional GBT device cut-off circuit shown in the figure, under normal working conditions: the controller 10 outputs the control signal through the first pin IO1 and the second pin IO2, and the strong pull-up PMOS (Q02) and the strong pull-down NMOS (Q03) of the gate are driven by the amplifier circuit 11 to control the potential of the G point to 15V or -10V, so that the G point has a strong ability to output and absorb current, so that the gate capacitor C01 of Q04 (IGBT device) can be quickly charged and discharged. When the upper tube Q02 is turned on and the lower tube Q03 is turned off, the gate capacitor C01 is fully charged to 15V, the gate of the IGBT device Q04 is at a high level, and the IGBT device Q04 is turned on; when the upper tube Q02 is turned off and the lower tube Q03 is turned on, the gate capacitor C01 is discharged to -10V, the gate of the IGBT device Q04 is at a low level, and the IGBT device Q04 is turned off;

[0003] However, if a large current flows through the IGBT device Q04, the controller 10 receives a short-circuit fault (the short-circuit fault will be detected only when the gate voltage of the IGBT device Q04 is at a high level). At this time, if the "upper tube Q02 is turned off and the lower tube Q03 is turned on" is directly used, it is a hard shutdown, which has a relatively large hazard. That is, the current of the IGBT device Q04 is relatively large under the short-circuit condition. Direct shutdown will produce a large voltage spike that will harm the IGBT device Q04 itself and affect its life. Utility Model Content

[0004] 1. Technical issues to be solved

[0005] In view of the deficiencies in the prior art, the utility model provides an IGBT soft shutdown circuit with low peak voltage, which can solve the above technical problems.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the utility model provides the following technical solutions: a low peak voltage IGBT soft shutdown circuit, comprising a controller, an amplifier module, a first resistor, a second resistor, a first transistor, a second transistor, a third resistor, a fourth resistor, a first capacitor and an IGBT device, wherein the first pin of the controller is connected to the amplifier module through the first resistor, the second pin of the controller is connected to the amplifier module through the second resistor, the first output end of the amplifier module is connected to one end of the third resistor through the first transistor, the second output end of the amplifier module is connected to one end of the fourth resistor through the second transistor, the other end of the third resistor and the other end of the fourth resistor are connected to the gate of the IGBT device, one end of the first capacitor is connected to the gate of the IGBT device, and the first capacitor is connected to the gate of the IGBT device. The other end of the capacitor is connected to the output end of the IGBT device, and is characterized in that it also includes: a fifth resistor, one end of which is connected to one end of the first resistor; a first triode, whose collector is connected to the other end of the fifth resistor and whose emitter is grounded; a sixth resistor, one end of which is connected to the third pin of the controller and the other end is connected to the base of the first triode; a seventh resistor, one end of which is connected to the third pin of the controller and the other end is grounded; an eighth resistor, one end of which is connected to one end of the seventh resistor; a second capacitor, one end of which is connected to the other end of the eighth resistor and the other end is grounded; a voltage regulator, whose cathode end is connected to the other end of the eighth resistor and its anode end is grounded; a second triode, whose base is connected to the other end of the eighth resistor, its collector is connected to the gate of the IGBT device through a ninth resistor, and its emitter is grounded through a tenth resistor.

[0008] Furthermore, both the first transistor and the second transistor are NPN transistors.

[0009] (III) Beneficial effects

[0010] Compared with the prior art, the utility model provides an IGBT soft-shutdown circuit with low peak voltage, which has the following beneficial effects: the IGBT soft-shutdown circuit with low peak voltage disclosed in the utility model includes a controller, an amplification module, a first resistor, a second resistor, a first transistor, a second transistor, a third resistor, a fourth resistor, a first capacitor, an IGBT device, a fifth resistor, a first triode, a sixth resistor, a seventh resistor, an eighth resistor, a second capacitor, a voltage regulator and a second triode. Through the above-mentioned method, the utility model can reduce the current flowing through the IGBT device, avoid short-circuit failure of the controller, and can reduce the short-circuit current flowing through the IGBT device to a relatively small state under short-circuit conditions, thereby realizing hard shutdown of the IGBT device under the condition of small on-current, and can reduce the peak voltage of the IGBT device to a smaller level when it is turned off, avoid damage to the IGBT device, and improve the service life of rail transit equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a traditional IGBT turn-off circuit;

[0012] Figure 2 The utility model is a schematic diagram of the structure of the IGBT soft shutdown circuit with low peak voltage. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0014] like Figure 2 As shown, the utility model provides an IGBT soft shutdown circuit with low peak voltage, which includes a controller 10, an amplification module 11, a first resistor R06, a second resistor R07, a first transistor Q02, a second transistor Q03, a third resistor RON, a fourth resistor ROFF, a first capacitor (i.e., a gate capacitor) C01, an IGBT device Q04, a fifth resistor R5, a first transistor Q1, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a second capacitor C02, a voltage regulator D and a second transistor Q2.

[0015] In this embodiment, the first pin I01 of the controller 10 is connected to the amplifying module 11 through the first resistor R06, the second pin I02 of the controller 10 is connected to the amplifying module 11 through the second resistor R07, the first output end of the amplifying module 11 is connected to one end of the third resistor RON through the first transistor Q02, the second output end of the amplifying module 11 is connected to one end of the fourth resistor ROFF through the second transistor Q03, the other end of the third resistor RON and the other end of the fourth resistor ROFF are connected to the gate of the IGBT device Q04, one end of the first capacitor C01 is connected to the gate of the IGBT device Q04, and the other end of the first capacitor C01 is connected to the output end of the IGBT device Q04. It should be understood that the controller 10, the amplifying module 11, the first resistor R06, the second resistor R07, the first transistor Q02, the second transistor Q03, the third resistor RON, the fourth resistor ROFF, the first capacitor (i.e., the gate capacitor) C01 and the IGBT device Q04 of this embodiment can be implemented by products in the prior art, and its specific working principle is also the prior art, that is, reference can be made to the description of the background art. Figure 1 The principle.

[0016] One end of the fifth resistor R5D is connected to one end of the first resistor R06.

[0017] The collector of the first transistor Q1 is connected to the other end of the fifth resistor R5 , and the emitter of the first transistor Q1 is grounded GND.

[0018] One end of the sixth resistor R6 is connected to the third pin I03 of the controller 10 , and the other end of the sixth resistor R6 is connected to the base of the first transistor Q1 .

[0019] One end of the seventh resistor R7 is connected to the third pin I03 of the controller 10 , and the other end of the seventh resistor R7 is grounded GND.

[0020] One end of the eighth resistor R8 is connected to one end of the seventh resistor R7.

[0021] One end of the second capacitor C02 is connected to the other end of the eighth resistor R8 , and the other end of the second capacitor C02 is grounded GND.

[0022] The cathode terminal of the voltage regulator tube D is connected to the other end of the eighth resistor R8, and the anode terminal of the voltage regulator tube D is grounded CND.

[0023] The base of the second transistor Q2 is connected to the other end of the eighth resistor R8, the collector of the second transistor Q2 is connected to the gate of the IGBT device Q04 through the ninth resistor R9, and the emitter of the second transistor Q2 is grounded GND through the tenth resistor R10.

[0024] In this embodiment, the first transistor Q1 and the second transistor Q2 are both NPN transistors.

[0025] The specific working principle is as follows:

[0026] At a certain moment: the output signal of the first pin I01 of the controller 10 is high level, which is amplified by the amplifier module 11 and drives the first transistor Q02 to turn on; the output of the second pin I02 of the controller 10 is low level, which is amplified by the amplifier module 11 and drives the second transistor Q03 to turn off; at this time, the IGBT device Q04 is in the on state, and the third pin I03 of the controller 10 outputs a low level at this time, and the first transistor Q1 is in the off state;

[0027] If the peripheral circuit of the IGBT device Q04 is short-circuited due to external reasons, the current flowing through the IGBT device Q04 will become very large, and the controller 10 determines that the soft shutdown circuit needs to be started. On the one hand, the third pin I03 of the controller 10 drives the first transistor Q1 to turn on through the sixth resistor R6, so that the drive signal of the first transistor Q02 is first flipped to a low level, and the first transistor Q02 is turned off. At this time, the gate of the IGBT device Q04 becomes a floating state, and the voltage of the first capacitor C01 is maintained at 15V; on the other hand, the third pin I03 of the controller 10 charges the second capacitor C02 for a period of time (a short delay) through the eighth resistor R8, which is generally designed to be 4-8us, to shield some false triggers (such as short circuit fault detection). After the voltage of the second capacitor C02 is established, the voltage regulator D clamps the voltage of the base of the second transistor Q2 and the tenth resistor R10. When the base voltage of the second transistor Q2 is constant, the voltage across the tenth resistor R10 is constant, and the collector current flowing through the tenth resistor R10 and the second transistor Q2 is constant (constant current source). Since the collector of the second transistor Q2 is connected to the gate of the IGBT device Q04 (i.e., point G), the constant current source supplies a gate capacitor of the IGBT device Q04 (i.e., the first capacitor C01, which is suspended at this time). ) performs constant current discharge, the gate capacitance C01 of the IGBT device Q04 drops linearly to about 7V, and the short-circuit current flowing through the IGBT device Q04 drops to a relatively small state (this rule can be known from the output characteristic curve of the IGBT device Q04). At this time, the second pin IO2 of the controller 10 outputs a high level and then turns on the second transistor Q03 after passing through the amplifying module 11, and hard turns off the IGBT device Q04 under the condition of a small on-current, which can reduce the turn-off peak of the IGBT device Q04 to a smaller level.

[0028] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low peak voltage IGBT soft shutdown circuit, comprising a controller, an amplifier module, a first resistor, a second resistor, a first transistor, a second transistor, a third resistor, a fourth resistor, a first capacitor and an IGBT device, wherein the first pin of the controller is connected to the amplifier module through the first resistor, the second pin of the controller is connected to the amplifier module through the second resistor, the first output end of the amplifier module is connected to one end of the third resistor through the first transistor, the second output end of the amplifier module is connected to one end of the fourth resistor through the second transistor, the other end of the third resistor and the other end of the fourth resistor are connected to the gate of the IGBT device, one end of the first capacitor is connected to the gate of the IGBT device, and the other end of the first capacitor is connected to the output end of the IGBT device, characterized in that: Also includes: a fifth resistor, one end of which is connected to one end of the first resistor; A first triode, whose collector is connected to the other end of the fifth resistor and whose emitter is grounded; a sixth resistor, one end of which is connected to the third pin of the controller, and the other end of which is connected to the base of the first transistor; a seventh resistor, one end of which is connected to the third pin of the controller, and the other end of which is grounded; an eighth resistor, one end of which is connected to one end of the seventh resistor; A second capacitor, one end of which is connected to the other end of the eighth resistor, and the other end of which is grounded; A voltage regulator tube, a cathode terminal of which is connected to the other end of the eighth resistor, and an anode terminal of which is grounded; The second triode has a base connected to the other end of the eighth resistor, a collector connected to the gate of the IGBT device through a ninth resistor, and an emitter connected to the ground through a tenth resistor.

2. The low peak voltage IGBT soft turn-off circuit according to claim 1, characterized in that: The first transistor and the second transistor are both NPN transistors.

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