CN110350484A - A kind of IGBT short trouble fast protection method and circuit - Google Patents
A kind of IGBT short trouble fast protection method and circuit Download PDFInfo
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- CN110350484A CN110350484A CN201910556700.1A CN201910556700A CN110350484A CN 110350484 A CN110350484 A CN 110350484A CN 201910556700 A CN201910556700 A CN 201910556700A CN 110350484 A CN110350484 A CN 110350484A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1203—Circuits independent of the type of conversion
Abstract
The present invention provides a kind of IGBT short trouble fast protection method and circuit, including short-circuit detecting circuit, gate logic and amplifying circuit.Using compared with normal opening state, the gate voltage variable condition different from collector voltage carries out short trouble detection when occurring short-circuit, push-pull amplifier circuit is controlled by logic circuit, in time turns off IGBT.The present invention can be improved short trouble detection rates, and required short-circuit detecting device and detection circuit are simple, easy to accomplish.
Description
Technical field
The present invention relates to a kind of IGBT short trouble fast protection method and circuits, belong to power electronics field.
Background technique
IGBT short-circuit protection is the key factor for improving power electronic system reliability.Traditional surrender and short-circuit protection side
Method is the collector-emitter voltage by detecting IGBT, to determine whether that IGBT short trouble occurs.In this protection side
It needs that blanking circuit is arranged in method, to avoid the false triggering short-circuit protection during IGBT turn-on transients.However in order to make driving plate
With versatility, it usually needs the longer blanking time is arranged, thus increases short circuit loss, so that junction temperature rises, increases
Impact of the short trouble to device.Other than surrender and method, currently used method is also from short circuit current information and gate pole
Two aspects of information extraction carry out short-circuit protection, such as: it is extracted using the induced potential of power transmitter and auxiliary transmission interpolar
Short circuit current, the variation of gate voltage or gate charge when according to short trouble.These methods are primarily to improve short circuit
Rate is protected, the influence of noise reduction time is eliminated, however compared to traditional surrender and method, generally need a large amount of operation amplifier
Device carries out the extraction of information, and need according to the specific application environment carry out the parameter designing of detection circuit, versatility compared with
Difference is not widely used.Thus short-circuit protection rate can either be improved by researching and developing one kind, and not need excessive detection
The short-circuit protection method of element becomes particularly important.
Summary of the invention
The present invention is directed to overcome the shortcomings of in the prior art, a kind of IGBT short trouble fast protection method and electricity are proposed
Road.The circuit can be improved short-circuit protection rate, and specific technical solution is as follows:
A kind of IGBT short trouble fast protection circuit, comprising: short-circuit detecting circuit, gate logic and amplifying circuit；
The short-circuit detecting circuit, it is short to judge whether to occur for detecting the state of collector voltage and gate voltage
Road failure, and fault-signal is exported to gate logic；
The gate logic judges to need open-minded for the pwm switching signal and fault-signal according to peripheral control unit
It is also off IGBT to be measured, be used for and exports control signal to amplifying circuit；
The amplifying circuit, the control signal for being exported according to gate logic export positive driving voltage V to IGBTCC
Or negative driving voltage VEE, realize opening and turning off for IGBT；
Wherein: gate logic receives switching signal VpwmWith fault-signal Vfault, and control signal is exported to amplifying circuit
Vp；Short-circuit detecting circuit detects the collector voltage V of IGBT to be measuredCEWith gate voltage VG, and failure is exported to gate logic
Signal Vfault；Amplifying circuit receives control signal Vp, output end connects the gate pole of IGBT to be measured.
As an improvement of the present invention, the short-circuit detecting circuit, comprising: collector detection circuit, gate pole detection electricity
Road, fault judging circuit；Wherein: collector detection circuit input terminal detection circuit detects collector voltage VCE, output end and therefore
The first input end for hindering decision circuitry is connected；Gate pole detection circuit input terminal detects gate voltage VG, output end and breakdown judge
Second input terminal of circuit is connected；Fault judging circuit output end exports fault-signal Vfault。
As an improvement of the present invention, the collector detection circuit, real-time detection collector voltage state, comprising:
Diode D1, diode D2, diode D3, resistance R1, capacitor C1, switch Q1；Wherein: diode D1Cathode reception survey IGBT
Collector, anode and resistance R1One end, capacitor C1One end, diode D2Anode, diode D3Cathode, p-type switching tube
Q1Base stage be connected, resistance R1The other end, diode D2Cathode and p-type switching tube Q1Emitter and positive driving voltage VCC
It is connected；Capacitor C1The other end and diode D3Plus earth.
As an improvement of the present invention, the gate pole detection circuit, using diode D4Real-time detection gate pole state, two
Pole pipe D4Anode connect the gate pole of IGBT to be measured.
As an improvement of the present invention, the fault judging circuit, according to the variation of gate voltage and collector voltage
State judges whether that short trouble occurs, and exports fault-signal to the gate logic, comprising: resistance R2, resistance R3, electricity
Hinder R4, p-type switching tube Q2, in which: resistance R2One end and p-type switching tube Q1Collector, p-type switching tube Q2Base stage, resistance
R3One end be connected；Resistance R3The other end connect reference voltage Vref；Resistance R2The other end and diode D4Cathode, p-type
Switching tube Q2Emitter be connected, p-type switching tube Q2Collector and resistance R4One end be connected, and export fault-signal Vfault；
Resistance R4The other end and negative driving voltage VEEIt is connected.
As an improvement of the present invention, the p-type switching tube Q1And Q2Using the very fast device for power switching of switching rate,
Such as BJT or MOSFET.
As an improvement of the present invention, the gate logic can be used and build logic electricity with door or NAND gate chip
Road can also be used digit chip FPGA/CPLD and carry out logic control.
A kind of IGBT short trouble fast protection method, which is characterized in that short-circuit protection method are as follows:
Transient state is opened in IGBT to be measured, if gate voltage rises to reference voltage VrefWhen, collector voltage VCERemain height
Voltage, then short-circuit detecting circuit identifies short trouble, and rapidly switches off IGBT to be measured.
In IGBT on state to be measured, if due to voltage spikes occurs in gate pole, short-circuit detecting circuit identifies short trouble, and fast
Speed turns off IGBT to be measured.
As an improvement of the present invention, the short-circuit detecting circuit includes: collector detection circuit, gate pole detection electricity
Road, fault judging circuit；Wherein, collector detection circuit input terminal detection circuit detects collector voltage VCE, output end and therefore
The first input end for hindering decision circuitry is connected；Gate pole detection circuit input terminal detects gate voltage VG, output end and breakdown judge
Second input terminal of circuit is connected；Fault judging circuit output end exports fault-signal Vfault。
As an improvement of the present invention, detailed process is as follows for the short-circuit detecting circuit identification short trouble:
As open signal VpWhen wm is high level, if IGBT be positive it is normally opened logical, in gate voltage VGRise to Miller platform
Before, collector voltage VCEIt is still high voltage, collector detection circuit output voltage is Vref, since gate pole detection circuit exports electricity
Pressure is equal to collector detection circuit output voltage, thus fault judging circuit not output short-circuit fault-signal；
After entering Miller platform, VCEIt will fall rapidly upon to conduction voltage drop, then collector detection circuit output voltage is
VCC, gate pole detection circuit output voltage is less than VCC, thus fault judging circuit not lead by output short-circuit failure, hereafter IGBT entrance
Logical state, VGContinue to rise to VCC, fault judging circuit not output short-circuit fault-signal；
If IGBT is when opening transient state generation short trouble, as gate voltage VGRise to reference voltage VrefWhen, collector
Voltage VCEHigh voltage is remained, then collector detection circuit output voltage is Vref, gate pole detection circuit output voltage is greater than at this time
Collector detection circuit, fault judging circuit output short-circuit fault-signal, rapidly turns off IGBT to be measured；
If IGBT is when short trouble occurs on state, collector current is risen rapidly, and emitter inductance generates induction
Potential leads to gate voltage VGDue to voltage spikes is generated, gate pole detection circuit output voltage is higher than VCC, due to collector voltage VCEStill
For conduction voltage drop, collector detection circuit output voltage is still positive driving voltage VCC, thus the event of fault judging circuit output short-circuit
Hinder signal, rapidly turns off IGBT to be measured.
Compared with prior art, the invention has the following advantages that
Influence of the present invention according to short trouble to gate pole and collector passes through real-time detection gate voltage and collector electricity
Pressure, quickly judges short trouble, eliminate tradition move back in saturation process as the wrong report failure that prevents normal opening process from occurring and
The blanking time of setting improves the protection rate of short circuit.
Detection circuit of the present invention is simple, and without operational amplifier carry out parameter extraction, reduce circuit cost with
Circuit area, versatility are preferable.
Detailed description of the invention
Below with reference to attached drawing, the invention will be further described:
Fig. 1 is structural block diagram of the invention；
Fig. 2 is short-circuit detecting circuit structural block diagram；
Fig. 3 is circuit diagram of the invention；
Waveform schematic diagram when Fig. 4 is IGBT normal switch；
Fig. 5 is IGBT in the waveform schematic diagram for opening transient state generation short-circuit protection；
Fig. 6 is the waveform schematic diagram that short-circuit protection occurs on state for IGBT；
Fig. 7 is the schematic diagram that gate pole clamp circuit is arranged；
Fig. 8 is the waveform schematic diagram that short-circuit protection occurs on state for IGBT after gate pole clamp circuit is arranged；
Fig. 9 is the schematic diagram that soft breaking circuit is arranged；
Figure 10 is that IGBT is opening the short-circuit experimental waveform protected using conventional method of transient state generation；
Figure 11 is that IGBT is opening transient state generation short circuit using the experimental waveform of the invention protected；
Figure 12 is the experimental waveform that IGBT is protected on state generation short circuit using conventional method；
Figure 13 is the experimental waveform that IGBT is protected on state generation short circuit using the present invention；
Specific embodiment:
In order to be more clearly understood that the content of present invention, with reference to the accompanying drawing and specific embodiment carries out the present invention
Explanation.
Embodiment 1: a kind of IGBT short trouble fast protection circuit, each unit connection relationship of the present invention are shown referring to Fig.1.
It include: short-circuit detecting circuit, gate logic and amplifying circuit.Wherein: gate logic receives switching signal Vpwm
With fault-signal Vfault, and control signal V is exported to amplifying circuitp；Short-circuit detecting circuit detects the collector electricity of IGBT to be measured
Press VCEWith gate voltage VG, and fault-signal V is exported to gate logicfault；Amplifying circuit receives control signal Vp, output end
Connect the gate pole of IGBT to be measured.
Short-circuit detecting circuit detects the state of collector voltage and gate voltage, to judge whether to occur short trouble, and
Fault-signal is exported to gate logic, comprising: collector detection circuit, gate pole detection circuit, fault judging circuit.Short circuit inspection
Slowdown monitoring circuit connection relationship is referring to shown in Fig. 2, in which: collector detection circuit input terminal detection circuit detects collector voltage VCE,
Output end is connected with the first input end of fault judging circuit；Gate pole detection circuit input terminal detects gate voltage VG, output end
It is connected with the second input terminal of fault judging circuit；Fault judging circuit output end exports fault-signal Vfault。
The specific device principle figure of each unit provided in this embodiment is as shown in Figure 3.
Collector detection circuit, real-time detection collector voltage state, comprising: diode D1, diode D2, diode D3,
Resistance R1, capacitor C1, switch Q1.Wherein: diode D1Cathode reception survey the collector of IGBT, anode and resistance R1One end,
Capacitor C1One end, diode D2Anode, diode D3Cathode, p-type switching tube Q1Base stage be connected, be；Resistance R1It is another
One end, diode D2Cathode and p-type switching tube Q1Emitter and positive driving voltage VCCIt is connected；Capacitor C1The other end and two
Pole pipe D3Plus earth.
Gate pole detection circuit, using diode D4Real-time detection gate pole state, diode D4Anode connect IGBT's to be measured
Gate pole.
Fault judging circuit judges whether generation short trouble according to the variable condition of gate voltage and collector voltage,
And fault-signal is exported to the gate logic, comprising: resistance R2, resistance R3, resistance R4, p-type switching tube Q2, in which: resistance
R2One end and p-type switching tube Q1Collector, p-type switching tube Q2Base stage, resistance R3One end be connected；Resistance R3The other end
Connect reference voltage Vref；Resistance R2The other end and diode D4Cathode, p-type switching tube Q2Emitter be connected, p-type switch
Pipe Q2Collector and resistance R4One end be connected, and export fault-signal Vfault；Resistance R4The other end and negative driving voltage
VEEIt is connected.
Gate pole and collector voltage detection circuit, switch Q1And Q2Using the very fast device for power switching of switching rate, such as BJT
Or MOSFET.
Gate logic judges to need to open also to be off according to the pwm switching signal and fault-signal of peripheral control unit
IGBT to be measured, and control signal is exported to amplifying circuit；It can be used and build logic circuit with door or NAND gate chip, can also be used
Digit chip FPGA/CPLD carries out logic control；The present embodiment, which is used, builds logic circuit, such as Fig. 3 with door or NAND gate chip
It is shown, comprising: NOT gate U1Or door U2, NAND gate U3, with door U4；Wherein: NOT gate U1First input end receive switching signal Vpwm,
U1Output end and U2The second input terminal and output end and U3First input end be connected；Or door U2First input end connect
Receive fault-signal Vfault, the second input terminal and U1Output end be connected, U2Output end and U2The second input terminal and U3First
Input terminal is connected；NAND gate U3First input end and U2Output end be connected, the second input terminal receives switching signal Vpwm；With door
U4First input end and U3Output end be connected, the second input terminal receive control signal Vpwm；With door U4Output end export control
Signal V processedp。
Amplifying circuit exports positive driving voltage V to IGBT according to the control signal that gate logic exportsCCOr negative driving
Voltage VEE, realize opening and turning off for IGBT；It include: N type switch tube Qn, p-type switching tube QpWith gate electrode resistance Rg；Wherein: N-type
Switching tube QnEmitter and p-type switching tube QpEmitter, gate electrode resistance RgOne end be connected；Gate electrode resistance RgThe other end
It is connected with the anode of IGBT gate pole to be measured, diode D4；N type switch tube QnCollector connect positive driving voltage VCC；P-type switch
Pipe QpCollector connect negative driving voltage VEE；N type switch tube QnBase stage and p-type switching tube QpBase stage receive control signal
Vp。
Short-circuit protection principle of the invention are as follows:
Gate pole and collector voltage detection circuit, reference voltage VrefValue IGBT Miller platform voltage and positive driving
Voltage VCCBetween.
(1) transient state normally is being opened, in gate voltage VGRise to reference voltage VrefWhen, collector voltage is via height
Voltage drops to conduction voltage drop.
IGBT normal switch process is as shown in Figure 4.
In t0Before moment, switching signal VpwmFor cut-off signals, amplifying circuit provides negative driving voltage V to gate poleEE, to be measured
IGBT is off state, collector side VCEBear full busbar voltage VDC, thus a point voltage Va is clamped at positive driving voltage VCC
On, p-type switching tube Q1For off state, b point voltage V at this timebWith c point voltage VcIt is equal to reference voltage Vref, thus p-type switchs
Pipe Q2It is held off.Fault-signal VfaultOutput voltage is VEE, no short trouble output.
In t0Moment, switching signal VpwmIt is switched to open signal, amplifying circuit is switched to positive voltage VCC, gate voltage VG
It begins to ramp up, before rising to Miller platform voltage, collector voltage VCEIt is still high voltage, p-type switching tube Q1Still it is held off
State, b point voltage VbWith c point voltage VcIt remains unchanged, thus p-type switching tube Q2It is held off, fault-signal VfaultOutput
Voltage not output short-circuit failure.
After entering Miller platform, VCEIt is dropped rapidly to conduction voltage drop.In t1Moment, a point voltage Va are less than positive driving electricity
Press VCC, so that p-type switching tube Q1It is open-minded, thus b point voltage VbWith c point voltage VcConvert the driving voltage V that is positiveCC, p-type switching tube
Q2It is held off, fault-signal VfaultNot output short-circuit failure.
Hereafter IGBT enters on state, VGContinue to rise, b point voltage VbWith c point voltage VcRemain VCC, failure letter
Number VfaultNot output short-circuit failure.
In t3Moment, switching signal VpwmCut-off signals are switched to, amplifying circuit switches the driving voltage V that is negativeEE, gate pole electricity
Press VGStart to be dropped rapidly to Miller platform voltage, it is made to be less than reference voltage Vref, b point voltage VbWith c point voltage VcStill keep
Be positive driving voltage VCC；With collector voltage VCEIt is gradually increasing by conduction voltage drop, arrives t4Moment, a point voltage Va start to be clamped
Position is in positive driving voltage VCCOn, so that p-type switching tube Q1Shutdown, b point voltage VbWith c point voltage VcBe converted to reference voltage Vref；
In entire turn off process, b point voltage VbConsistently equal to c point voltage Vc, thus p-type switching tube Q2It is held off, failure letter
Number VfaultNot output short-circuit failure.
(2) when short circuit occurs when IGBT to be measured opens transient state, when gate pole rises to reference voltage VrefWhen, collector electricity
Press VCERemain high voltage, short-circuit detecting circuit identifies that short trouble, gate logic control amplifying circuit accordingly, rapidly will be to
Survey IGBT shutdown.
IGBT to be measured is as shown in Figure 5 in the protection process for opening transient state generation short circuit.
In t5Moment, switching signal VpwmIt is switched to open signal by cut-off signals, amplifying circuit is switched to positive voltage VCC,
Gate voltage VGStart to continue rising, and short trouble has occurred, is influenced by saturation effect is moved back, collector voltage VCEAlways it protects
High voltage is held, a point voltage Va is clamped at positive driving voltage VCCOn, p-type switching tube Q2It is held off, thus b point voltage
VbWith c point voltage VcFor reference voltage Vref。
At the t6 moment, gate voltage VGIt will be above reference voltage Vref, b point voltage VbWith c point voltage VcIt begins to ramp up, with R2
And R3Form partial pressure, b point voltage VbWith c point voltage VcIt is respectively as follows:
Wherein: VD4For diode D4Conduction voltage drop.
B point voltage V at this timebBegin lower than c point voltage Vc, so that p-type switching tube Q2It is open-minded, fault-signal VfaultIt is converted to
High level, output short-circuit failure.After gate logic receives short trouble, it is immediately controlled amplifying circuit, and at the t7 moment to door
Pole provides negative driving voltage VEE, IGBT to be measured is turned off.
(3) when short circuit occurs in IGBT on state to be measured, if without gate pole clamp circuit, on collector current is quick
During rising, gate voltage VGGeneration due to voltage spikes, and collector V at this timeCEFor conduction voltage drop, short-circuit detecting circuit is known accordingly
Other short trouble, gate logic control amplifying circuit, rapidly turn off IGBT to be measured.
IGBT to be measured is as shown in Figure 6 in the protection process that short circuit occurs on state.
In t8At the moment, since external devices are opened so that short trouble occurs for IGBT to be measured, collector current is risen rapidly,
Emitter inductance generates induced potential, leads to gate voltage VGDue to voltage spikes is generated, by c point voltage VcIt raises, at this point, due to collection
Electrode voltage VCEIt is still conduction voltage drop, p-type switching tube Q1For opening state, b point voltage VbStill be positive driving voltage VCC, thus b
Point voltage VbLess than c point voltage Vc, p-type switching tube Q2It is open-minded, fault-signal VfaultBe converted to high level, output short-circuit failure.Door
After logic circuit receives short trouble, amplifying circuit is immediately controlled, and provide negative driving voltage V to gate pole at the t9 momentEE, will be to
Survey IGBT shutdown.
Embodiment 2:
If being provided with gate pole clamp circuit in amplifying circuit, as shown in Figure 7.The anode of diode D5 connects IGBT's to be measured
Gate pole, cathode connect positive driving voltage VCC。
When short circuit occurs in IGBT on state to be measured, gate pole clamp circuit lives gate voltage peak restrained, nothing
Method generates apparent due to voltage spikes, then collector current continues to rise so that IGBT to be measured, which takes place, moves back saturated phenomenon, current collection
Pole tension VCEHigh voltage is risen very rapidly up to by conduction voltage drop, short-circuit detecting circuit identifies short trouble, gate logic control accordingly
Amplifying circuit processed rapidly turns off IGBT to be measured.
IGBT to be measured is then as shown in Figure 8 in the protection process that short circuit occurs on state.
In t8Moment, collector current rise rapidly, in t8-t9Gate pole clamp circuit presses down gate voltage spike in stage
It has made.After IGBT to be measured, which takes place, moves back saturated phenomenon, collector voltage VCEIt rises rapidly, and in t9Moment, a point voltage
Va is clamped at positive driving voltage VCCOn, p-type switching tube Q1For off state, b point voltage VbBy positive driving voltage VCCBecome:
B point voltage V at this timebLess than c point voltage Vc, then p-type switching tube Q2It is open-minded, fault-signal VfaultHigh level is converted to,
Output short-circuit failure, gate logic control amplifying circuit, rapidly turn off IGBT to be measured.
Compared with being not provided with gate pole clamp circuit, the short-circuit protection time point of the embodiment postpones backward.
Embodiment 3:
When being provided with soft breaking circuit in amplifying circuit, as shown in figure 9, the soft breaking circuit of amplifying circuit includes: that p-type is opened
Close pipe Qs, resistance Rgs, in which: the collector of p-type switching tube Qs and negative driving voltage VEEIt is connected, emitter and resistance RgsOne
End is connected, resistance RgsThe other end connect the gate pole of IGBT to be measured.
What the present embodiment used builds logic circuit with door or NAND gate chip, comprising: NOT gate U1Or door U2, NAND gate
U3, with door U4；Wherein: NOT gate U1First input end receive switching signal Vpwm, U1Output end and U2The second input terminal and defeated
Outlet and U3First input end be connected；Or door U2First input end receive fault-signal Vfault, the second input terminal and U1's
Output end is connected, U2Output end and U2The second input terminal and U3First input end be connected；NAND gate U3First input end
With U2Output end be connected, the second input terminal receives switching signal Vpwm；With door U4First input end and U3Output end be connected,
Second input terminal receives control signal Vpwm；With door U4Output end output control signal Vp.Control signal VpControl amplifying circuit
N type switch tube QnAnd soft switching switching tube QsOpen and turn off.Switching signal VpwmControl the p-type switching tube of amplifying circuit
QpOpen and turn off.
When the setting of soft breaking circuit is failure shutdown to avoid short circuit, excessively high collector current rate of change makes
Collector voltage generates excessively high due to voltage spikes, to prevent the breakdown of IGBT.
Make it in normal turn-off, amplifying circuit realizes conventional shutdown, and when short circuit occurs, gate logic is opened soft
Breaking circuit slows down turn off process, reduces shutdown over-voltage.
Embodiment 4:
A kind of IGBT short trouble fast protection method, the specific method is as follows: transient state is opened in IGBT to be measured, if gate pole is electric
Pressure rises to reference voltage VrefWhen, collector voltage VCERemaining high voltage, then short-circuit detecting circuit identifies short trouble, and
Rapidly switch off IGBT to be measured.
In IGBT on state to be measured, if due to voltage spikes occurs in gate pole, short-circuit detecting circuit identifies short trouble, and fast
Speed turns off IGBT to be measured.
Short-circuit detecting circuit includes: collector detection circuit, gate pole detection circuit, fault judging circuit；Wherein, collector
Detection circuit input terminal detection circuit detects collector voltage VCE, output end is connected with the first input end of fault judging circuit；
Gate pole detection circuit input terminal detects gate voltage VG, output end is connected with the second input terminal of fault judging circuit；Failure is sentenced
Deenergizing output end exports fault-signal Vfault。
Short-circuit detecting circuit identifies short trouble, and detailed process is as follows: as open signal VpWhen wm is high level, if
IGBT be positive it is normally opened logical, in gate voltage VGBefore rising to Miller platform, collector voltage VCEIt is still high voltage, collector detection
Circuit output voltage is Vref, since gate pole detection circuit output voltage is equal to collector detection circuit output voltage, thus failure
Decision circuitry not output short-circuit fault-signal；
After entering Miller platform, VCEIt will fall rapidly upon to conduction voltage drop, then collector detection circuit output voltage is
VCC, gate pole detection circuit output voltage is less than VCC, thus fault judging circuit not lead by output short-circuit failure, hereafter IGBT entrance
Logical state, VGContinue to rise to VCC, fault judging circuit not output short-circuit fault-signal；
If IGBT is when opening transient state generation short trouble, as gate voltage VGRise to reference voltage VrefWhen, collector
Voltage VCEHigh voltage is remained, then collector detection circuit output voltage is Vref, gate pole detection circuit output voltage is greater than at this time
Collector detection circuit, fault judging circuit output short-circuit fault-signal, rapidly turns off IGBT to be measured.
If IGBT is when short trouble occurs on state, collector current is risen rapidly, and emitter inductance generates induction
Potential leads to gate voltage VGDue to voltage spikes is generated, gate pole detection circuit output voltage is higher than VCC, due to collector voltage VCEStill
For conduction voltage drop, collector detection circuit output voltage is still positive driving voltage VCC, thus the event of fault judging circuit output short-circuit
Hinder signal, rapidly turns off IGBT to be measured.
If amplifying circuit is equipped with gate pole clamp circuit, when short circuit occurs in IGBT on state to be measured, gate pole clamper is electric
Gate voltage peak restrained is lived on road, can not generate apparent due to voltage spikes, then collector current continues to rise so as to be measured
IGBT, which takes place, moves back saturated phenomenon, collector voltage VCEHigh voltage, short-circuit detecting circuit evidence are risen very rapidly up to by conduction voltage drop
This identification short trouble, rapidly turns off IGBT to be measured.
Embodiment 5:
The present invention is moved back compared with saturation process carries out experiment with tradition, IGBT module uses company, Infineon
FF1400R17IP4, positive driving voltage V in amplifying circuitCCFor 15V, negative driving voltage VEEFor -15V, reference voltage VrefUsing
The zener diode of 12V, model MM1Z12.Other device types of short-circuit detecting circuit are respectively as follows: QnFor ZXTN2010Z, Qp
For ZXTP2012Z, Q1And Q2For S8050, D1For STTH112U, D2And D3For BAV99.When short circuit occurs to open wink in IGBT to be measured
When state, traditional short-circuit waveform is as shown in Figure 10.Device under test is open-minded when 4 μ s, and short circuit current persistently rises.Due to needing
The blanking time is wanted, driving just turns off device under test when 11 μ s, this moment, maximum short circuit current 4.3kA.It is short with tradition
Road waveform is compared, and short-circuit waveform of the invention is as shown in figure 11.Same IGBT to be measured is open-minded in 4 μ s, when gate voltage is rising
When to 12V, amplifying circuit detects short trouble, and turns off IGBT to be measured when 7.4 μ s.Maximum short circuit current this moment
Only 2.9kA.
When short circuit occurs in IGBT on state to be measured, traditional short-circuit waveform is as shown in figure 12.IGBT to be measured exists
Short trouble occurs when 25.1 μ s, conventional method turns off IGBT to be measured after 4.1 μ s.Maximum short circuit current is 4.2kA this moment.
Short-circuit waveform of the invention is as shown in figure 13.After 25.1 μ s short trouble occurs for same IGBT to be measured, at this point, driving is according to door
The due to voltage spikes that pole occurs detects short trouble, and turns off IGBT to be measured at 1.2 μ s moment.Maximum short circuit current is only this moment
For 3600A.
Because regardless of the present invention is better than tradition and moves back saturation process from short circuit duration or short circuit current.
Compared with prior art, the invention has the following advantages that
Influence of the present invention according to short trouble to gate pole and collector passes through real-time detection gate voltage and collector electricity
Pressure, quickly judges short trouble, eliminate tradition move back in saturation process as the wrong report failure that prevents normal opening process from occurring and
The blanking time of setting improves the protection rate of short circuit.
And with it is existing based on the protection circuit and method of short circuit current information or gate pole information extraction compared with, the present invention inspection
Slowdown monitoring circuit is simple, and carries out parameter extraction without operational amplifier, reduces circuit cost and circuit area, versatility compared with
It is good.
It should be noted that above-described embodiment is only presently preferred embodiments of the present invention, there is no guarantors for the purpose of limiting the invention
Range is protected, the equivalent substitution or substitution made based on the above technical solution all belongs to the scope of protection of the present invention.
Claims (10)
1. a kind of IGBT short trouble fast protection circuit, comprising: short-circuit detecting circuit, gate logic and amplifying circuit；
The short-circuit detecting circuit, for detecting the state of collector voltage and gate voltage, to judge whether to occur short-circuit event
Barrier, and fault-signal is exported to gate logic；
The gate logic judges to need to open still for the pwm switching signal and fault-signal according to peripheral control unit
IGBT to be measured is turned off, be used for and exports control signal to amplifying circuit；
The amplifying circuit, the control signal for being exported according to gate logic export positive driving voltage V to IGBTCCOr it is negative
Driving voltage VEE, realize opening and turning off for IGBT；
Wherein: gate logic receives switching signal VpwmWith fault-signal Vfault, and control signal V is exported to amplifying circuitp；
Short-circuit detecting circuit detects the collector voltage V of IGBT to be measuredCEWith gate voltage VG, and fault-signal is exported to gate logic
Vfault；Amplifying circuit receives control signal Vp, output end connects the gate pole of IGBT to be measured.
2. IGBT short trouble fast protection circuit according to claim 1, which is characterized in that the short-circuit detecting electricity
Road, comprising: collector detection circuit, gate pole detection circuit, fault judging circuit；Wherein: the inspection of collector detection circuit input terminal
Slowdown monitoring circuit detects collector voltage VCE, output end is connected with the first input end of fault judging circuit；The input of gate pole detection circuit
End detection gate voltage VG, output end is connected with the second input terminal of fault judging circuit；The output of fault judging circuit output end
Fault-signal Vfault。
3. IGBT short trouble fast protection circuit according to claim 2, which is characterized in that the collector detection electricity
Road, real-time detection collector voltage state, comprising: diode D1, diode D2, diode D3, resistance R1, capacitor C1, switch Q1；
Wherein: diode D1Cathode reception survey the collector of IGBT, anode and resistance R1One end, capacitor C1One end, diode D2
Anode, diode D3Cathode, p-type switching tube Q1Base stage be connected, resistance R1The other end, diode D2Cathode and p-type
Switching tube Q1Emitter and positive driving voltage VCCIt is connected；Capacitor C1The other end and diode D3Plus earth.
4. IGBT short trouble fast protection circuit according to claim 2, which is characterized in that the gate pole detection electricity
Road, using diode D4Real-time detection gate pole state, diode D4Anode connect the gate pole of IGBT to be measured.
5. a kind of IGBT short trouble fast protection circuit according to claim 2, which is characterized in that the breakdown judge
Circuit judges whether that short trouble occurs, and electric to the gate logic according to the variable condition of gate voltage and collector voltage
Road exports fault-signal, comprising: resistance R2, resistance R3, resistance R4, p-type switching tube Q2, in which: resistance R2One end and p-type switch
Pipe Q1Collector, p-type switching tube Q2Base stage, resistance R3One end be connected；Resistance R3The other end connect reference voltage Vref；
Resistance R2The other end and diode D4Cathode, p-type switching tube Q2Emitter be connected, p-type switching tube Q2Collector and electricity
Hinder R4One end be connected, and export fault-signal Vfault；Resistance R4The other end and negative driving voltage VEEIt is connected.
6. the IGBT short trouble fast protection circuit according to claim 3 or 5, which is characterized in that the p-type switching tube
Q1And Q2Using the very fast device for power switching of switching rate, such as BJT or MOSFET.
7. IGBT short trouble fast protection circuit according to claim 1, which is characterized in that the gate logic,
It can be used and build logic circuit with door or NAND gate chip, digit chip FPGA/CPLD can also be used and carry out logic control.
8. a kind of IGBT short trouble fast protection method, which is characterized in that short-circuit protection method are as follows:
Transient state is opened in IGBT to be measured, if gate voltage rises to reference voltage VrefWhen, collector voltage VCERemain high electricity
Pressure, then short-circuit detecting circuit identifies short trouble, and rapidly switches off IGBT to be measured.
In IGBT on state to be measured, if due to voltage spikes occurs in gate pole, short-circuit detecting circuit identifies short trouble, and quickly closes
Break IGBT to be measured.
9. IGBT short trouble fast protection method according to claim 8, which is characterized in that the short-circuit detecting circuit
It include: collector detection circuit, gate pole detection circuit, fault judging circuit；Wherein, collector detection circuit input terminal detection electricity
Detect collector voltage V in roadCE, output end is connected with the first input end of fault judging circuit；The inspection of gate pole detection circuit input terminal
Survey gate voltage VG, output end is connected with the second input terminal of fault judging circuit；Fault judging circuit output end exports failure
Signal Vfault。
10. IGBT short trouble fast protection method according to claim 9, which is characterized in that the short-circuit detecting electricity
Road identifies short trouble, and detailed process is as follows:
As open signal VpWhen wm is high level, if IGBT be positive it is normally opened logical, in gate voltage VGBefore rising to Miller platform, collection
Electrode voltage VCEIt is still high voltage, collector detection circuit output voltage is Vref, since gate pole detection circuit output voltage is equal to
Collector detection circuit output voltage, thus fault judging circuit not output short-circuit fault-signal；
After entering Miller platform, VCEIt will fall rapidly upon to conduction voltage drop, then collector detection circuit output voltage is VCC, gate pole
Detection circuit output voltage is less than VCC, thus fault judging circuit not output short-circuit failure, hereafter IGBT enters on state, VG
Continue to rise to VCC, fault judging circuit not output short-circuit fault-signal；
If IGBT is when opening transient state generation short trouble, as gate voltage VGRise to reference voltage VrefWhen, collector voltage
VCEHigh voltage is remained, then collector detection circuit output voltage is Vref, gate pole detection circuit output voltage is greater than current collection at this time
Pole detection circuit, fault judging circuit output short-circuit fault-signal, rapidly turns off IGBT to be measured；
If IGBT is when short trouble occurs on state, collector current is risen rapidly, and emitter inductance generates induced potential,
Lead to gate voltage VGDue to voltage spikes is generated, gate pole detection circuit output voltage is higher than VCC, due to collector voltage VCEIt is still to lead
Logical pressure drop, collector detection circuit output voltage are still positive driving voltage VCC, thus fault judging circuit output short-circuit failure is believed
Number, IGBT to be measured is turned off rapidly.
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| CN201910556700.1A CN110350484A (en) | 2019-06-25 | 2019-06-25 | A kind of IGBT short trouble fast protection method and circuit |
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| CN111398763A (en) * | 2020-03-03 | 2020-07-10 | 广东芯聚能半导体有限公司 | IGBT device open circuit and short circuit detection method, system and storage medium |
| CN111830389A (en) * | 2020-07-31 | 2020-10-27 | 徐州中矿大传动与自动化有限公司 | IGBT junction temperature estimation system and method based on emitter power terminal temperature |
| CN112290926A (en) * | 2020-12-28 | 2021-01-29 | 杭州飞仕得科技有限公司 | IGBT drive circuit and IGBT protection method |
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| CN113922794A (en) * | 2020-07-08 | 2022-01-11 | 圣邦微电子（北京）股份有限公司 | Short-circuit protection circuit |
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