阅读说明：本技术 Igbt驱动短路保护检测电路 (IGBT drives short-circuit protection detection circuit ) 是由 赵晨凯 李艳伟 王亮亮 梁海刚 俞晓丽 王翠云 于 2019-08-21 设计创作，主要内容包括：本发明涉及IGBT的保护电路,具体为IGBT驱动短路保护检测电路。解决现有IGBT驱动短路保护检测电路短路保护时间受母线电压影响,易造成短路保护不及时的问题。该电路包括第一与非门U4,驱动板输入脉冲信号CMD-H处理电路,IGBT集射极电压状态采集电路；驱动板输入脉冲信号CMD-H处理电路的输出端TP-CMD-H与第一与非门U4的第一输入端相连,驱动板输入脉冲信号CMD-H接入第一与非门U4的第二输入端,IGBT集射极电压状态采集电路的输出端HZ_Vce与第一与非门U4的第三输入端相连,第一与非门U4的输出端作为IGBT驱动短路保护检测电路的输出FAILb。本发明无论母线电压变大或变小,短路保护的响应时间不变。(The present invention relates to the protection circuit of IGBT, specially IGBT drives short-circuit protection detection circuit.Solve the problem of that the existing IGBT driving short-circuit protection detection circuit short-circuit protection time is influenced to easily cause short-circuit protection not in time by busbar voltage.The circuit includes the first NAND gate U4, driving plate input pulse signal CMD-H processing circuit, IGBT collection emitter voltage state acquisition circuit；The output end TP-CMD-H of driving plate input pulse signal CMD-H processing circuit is connected with the first input end of the first NAND gate U4; driving plate input pulse signal CMD-H accesses the second input terminal of the first NAND gate U4; the output end HZ_Vce of IGBT collection emitter voltage state acquisition circuit is connected with the third input terminal of the first NAND gate U4, output FAILb of the output end of the first NAND gate U4 as IGBT driving short-circuit protection detection circuit.No matter busbar voltage becomes larger or becomes smaller the present invention, and the response time of short-circuit protection is constant.)

1. a kind of IGBT drives short-circuit protection detection circuit, which is characterized in that including the first NAND gate U4, driving plate input pulse Signal CMD-H processing circuit, IGBT collection emitter voltage state acquisition circuit；Driving plate input pulse signal CMD-H processing circuit Output end TP-CMD-H be connected with the first input end of the first NAND gate U4, driving plate input pulse signal CMD-H access the The second input terminal of one NAND gate U4, the output end Hz_Vce and the first NAND gate U4 of IGBT collection emitter voltage state acquisition circuit Third input terminal be connected, the output end of the first NAND gate U4 drives the output FAILb of short-circuit protection detection circuit as IGBT；

Driving plate input pulse signal CMD-H processing circuit includes first comparator U1 and the second NAND gate U2, first comparator The in-phase end of U1 is equipped with the first partial pressure branch being connected in series by 3rd resistor R3 and the 5th resistance R5, and first divides the one of branch Termination power, other end ground connection, connecting node and the same phase of first comparator U1 between 3rd resistor R3 and the 5th resistance R5 End connection；The reverse side of first comparator U1 is equipped with charge and discharge branch, and charge and discharge branch has by second resistance R2 and first capacitor The charging paths that C1 is connected in series, one end second resistance R2 of charging paths are connected with driving plate input pulse signal CMD-H, are another One end ground connection, the connecting node between second resistance R2 and first capacitor C1 are connected with the reverse side of first comparator U1；Charge and discharge There are also the discharge paths being connected in series by first resistor R1 and first diode D1, discharge paths to be parallel to second resistance for electric branch The both ends of the R2 and cathode of first diode D1 is connected with driving plate input pulse signal CMD-H；The output of first comparator U1 End is connected with an input terminal of the second NAND gate U2, and another input terminal and driving plate input pulse of the second NAND gate U2 is believed Number CMD-H is connected；Output end of the output end of second NAND gate U2 as driving plate input pulse signal CMD-H processing circuit TP-CMD-H；

IGBT collection emitter voltage state acquisition circuit includes that the in-phase end of the second comparator U3, the second comparator U3 is equipped with by the 7th Resistance R7 and the 8th resistance R8 be connected in series second partial pressure branch, second partial pressure branch both ends respectively with the current collection of IGBT Pole, emitter are connected, and the connecting node between the 7th resistance R7 and the 8th resistance R8 is connect with the in-phase end of the second comparator U3； The reverse side of second comparator U3, which is equipped with, divides branch, third by the third that the 9th resistance R9 and the tenth resistance R10 are connected in series Divide one end connection power supply of branch, the emitter of other end connection IGBT, the company between the 9th resistance R9 and the tenth resistance R10 Node is connect to be connected with the reverse side of the second comparator U3；The output end of second comparator U3 is adopted as IGBT collection emitter voltage state The output end Hz_Vce of collector.

2. IGBT according to claim 1 drives short-circuit protection detection circuit, which is characterized in that first comparator U1's is defeated Outlet is connected through the 6th resistance R6 with an input terminal of the second NAND gate U2.

3. IGBT according to claim 1 or 2 drives short-circuit protection detection circuit, which is characterized in that power supply 15V.

Technical field

The present invention relates to the protection circuit of IGBT, specially IGBT drives short-circuit protection detection circuit.

Background technique

IGBT has been more and more widely used in modern power electronics technology, and the driving circuit of IGBT is power electronics Interface between main circuit and control circuit is the important link of power electronic equipment, and the quality of performance is to entire circuit Working performance has a great impact.In switching power unit, since IGBT work is under conditions of high frequency, high pressure, high current, IGBT is set to be easy to damage.Thus, the design of the protection circuit of IGBT seems particularly important.

When the short-circuit protection of IGBT is commonly referred to as that inductance is smaller in short-circuit loop, loop current rapid increase works as electricity When stream rises to certain numerical value (generally 4-6 times of rated current), saturated phenomenon is moved back, at this time IGBT collection-emitter-base bandgap grading electricity Pressure is busbar voltage, and the loss of IGBT is very big, it is however generally that IGBT at most bears the short-circuit condition of 10us, and driving circuit will be IGBT is completely closed within 10us, protection at this time is overall safety for IGBT.When moving back saturated phenomenon, The collector emitter voltage of IGBT rises to busbar voltage from several volts, and variation is clearly, it is possible to according to IGBT current collection Pole emits the voltage of interpolar to determine whether short circuit occurs.

Fig. 1 is existing IGBT driving short-circuit protection detection circuit schematic diagram, its working principle is that:

A) when IGBT is turned off, MOSFET pipe Q is open-minded, and by clamped in 0V, comparator is not overturn voltage on capacitor Ca；

B) when IGBT is opened, MOSFET pipe Q turns off, and C point current potential (voltage between IGBT collector emitter) passes through resistance Rvce and resistance Rm charges to capacitor Ca, and A point current potential is finally the saturation voltage drop of IGBT, and comparator is not overturn；

C) when IGBT short circuit, C point current potential (collection emitter voltage) rises to busbar voltage, by resistance Rvce and resistance Rm to capacitor Ca charging, so that A point current potential improves rapidly, as load source, final A point current potential is equal to 15 V and adds diode Dm 15V power supply Pressure drop, then subtract the pressure drop on resistance Rm, after the response time, comparator overturning, driving plate quotes failure, Jin Ergen It is negative according to fault-signal control IGBT gate voltage, turns off IGBT.Because occur short circuit when, IGBT can only bear 10us when Between, comparator will invert in 10us, so Rm and Ca is used to adjust the response time.

Can be seen that busbar voltage difference from the above-mentioned course of work may cause IGBT short-circuit protection time difference.And it is female When line voltage is high, the short-circuit protection time can be less than 10us, but the short-circuit protection time can make greater than 10us when busbar voltage is lower Not in time at short-circuit protection, IGBT is damaged.

Summary of the invention

The present invention solves existing IGBT and the short-circuit protection detection circuit short-circuit protection time is driven to be influenced by busbar voltage, Yi Zao The problem of at short-circuit protection not in time, provides a kind of IGBT driving short-circuit protection detection circuit.The circuit no matter busbar voltage such as What changes, and when short circuit occurs, the short-circuit protection response time is all that 10us(can set fixed value), i.e., driver can be in 10us IGBT is turned off.

The present invention is achieved by the following technical scheme: IGBT drive short-circuit protection detection circuit, including first with it is non- Door U4, driving plate input pulse signal CMD-H processing circuit, IGBT collection emitter voltage state acquisition circuit；Driving plate inputs arteries and veins The output end TP-CMD-H for rushing signal CMD-H processing circuit is connected with the first input end of the first NAND gate U4, driving plate input Pulse signal CMD-H accesses the second input terminal of the first NAND gate U4, the output end of IGBT collection emitter voltage state acquisition circuit HZ_Vce is connected with the third input terminal of the first NAND gate U4, and the output end of the first NAND gate U4 drives short-circuit protection as IGBT The output FAILb of detection circuit；

Driving plate input pulse signal CMD-H processing circuit includes first comparator U1 and the second NAND gate U2, first comparator The in-phase end of U1 is equipped with the first partial pressure branch being connected in series by 3rd resistor R3 and the 5th resistance R5, and first divides the one of branch Termination power, other end ground connection, connecting node and the same phase of first comparator U1 between 3rd resistor R3 and the 5th resistance R5 End connection；The reverse side of first comparator U1 is equipped with charge and discharge branch, and charge and discharge branch has by second resistance R2 and first capacitor The charging paths that C1 is connected in series, one end second resistance R2 of charging paths are connected with driving plate input pulse signal CMD-H, are another One end (i.e. one end first capacitor C1) ground connection, connecting node and first comparator U1 between second resistance R2 and first capacitor C1 Reverse side be connected；There are also the discharge paths being connected in series by first resistor R1 and first diode D1, electric discharges for charge and discharge branch Branch circuit parallel connection is in the both ends of second resistance R2 and the cathode of first diode D1 is connected with driving plate input pulse signal CMD-H； The output end (through the 6th resistance R6) of first comparator U1 is connected with an input terminal of the second NAND gate U2, the second NAND gate U2 Another input terminal be connected with driving plate input pulse signal CMD-H；The output end of second NAND gate U2 is defeated as driving plate Enter the output end TP-CMD-H of pulse signal CMD-H processing circuit；

IGBT collection emitter voltage state acquisition circuit includes that the in-phase end of the second comparator U3, the second comparator U3 is equipped with by the 7th Resistance R7 and the 8th resistance R8 be connected in series second partial pressure branch, second partial pressure branch both ends respectively with the current collection of IGBT Pole, emitter are connected, and the connecting node between the 7th resistance R7 and the 8th resistance R8 is connect with the in-phase end of the second comparator U3； The reverse side of second comparator U3, which is equipped with, divides branch, third by the third that the 9th resistance R9 and the tenth resistance R10 are connected in series Divide one end connection power supply of branch, the emitter of other end connection IGBT, the company between the 9th resistance R9 and the tenth resistance R10 Node is connect to be connected with the reverse side of the second comparator U3；The output end of second comparator U3 is adopted as IGBT collection emitter voltage state The output end Hz_Vce of collector.

When work, when the collection emitter voltage of IGBT is higher than 500V, Hz_Vce is high (15V)；The collection emitter voltage of IGBT is low When 500V, Hz_Vce 0V.

(1) when CMD-H is low, TP-CMD-H is high level；When CMD-H is by low get higher, the charging branch of R2, C1 composition Road forms rising edge delay circuit, and the reverse side for just starting U1 is that low level is nonreversible, and TP-CMD-H is low level at this time；Work as warp After spending certain response time, the reverse side of U1 becomes high level, and U1 reversion, TP-CMD-H is high level at this time；The response time It is determined by the reversal voltage of R2, C1 charging paths formed and U1, is usually arranged as 10us.When driving plate input pulse signal When CMD-H is lower by height, the discharge paths that capacitor C1 is constituted through R1, D1 are discharged.

(2) such as first pulse of Fig. 3, when CMD-H is got higher by low, and IGBT is worked normally, TP-CMD-H becomes low level, IGBT is not in time for also open-minded at this time, and collection emitter voltage is height, therefore Hz_Vce is height, and FAILb is high level, fault-free hair at this time It is raw；When IGBT is open-minded after centainly postponing, IGBT collection emitter voltage be it is low, therefore Hz_Vce be it is low, FAILb is high electricity at this time Flat, fault-free occurs；When CMD-H is low, TP-CMD-H is high level, and IGBT is turned off at this time, and collection emitter voltage is height, therefore Hz_Vce is height, and FAILb is high level at this time, and fault-free occurs.

(3) such as second pulse of Fig. 3, when CMD-H is got higher by low, and short circuit occurs for IGBT, collection emitter voltage rises to bus Voltage, Hz_Vce are high level, and CMD-H is height at this time, but since TP-CMD-H at this time is low level, so when FAILb be height Level, fault-free occur, and after the response time, TP-CMD-H is high level, therefore FAILb is low level, and driving plate is quoted Short trouble, and then the gate voltage driven is negative, and turns off IGBT.

The problem of being influenced the present invention overcomes the driving short-circuit protection response time of the prior art by busbar voltage, Neng Goubao For card when no matter busbar voltage becomes larger or becomes smaller, the response time of short-circuit protection is constant, and then can timely protect IGBT, improves and produces The reliability of product.

Detailed description of the invention

Fig. 1 is the circuit diagram of the prior art；

Fig. 2 is circuit diagram of the invention；

Fig. 3 is clocked logic figure when the invention works.

Specific embodiment

IGBT drives short-circuit protection detection circuit, including the first NAND gate U4, driving plate input pulse signal CMD-H processing Circuit, IGBT collection emitter voltage state acquisition circuit；The output end TP- of driving plate input pulse signal CMD-H processing circuit CMD-H is connected with the first input end of the first NAND gate U4, and driving plate input pulse signal CMD-H accesses the first NAND gate U4's Second input terminal, the third input terminal of the output end HZ_Vce and the first NAND gate U4 of IGBT collection emitter voltage state acquisition circuit It is connected, output FAILb of the output end of the first NAND gate U4 as IGBT driving short-circuit protection detection circuit；

Driving plate input pulse signal CMD-H processing circuit includes first comparator U1 and the second NAND gate U2, first comparator The in-phase end of U1 is equipped with the first partial pressure branch being connected in series by 3rd resistor R3 and the 5th resistance R5, and first divides the one of branch Termination power, other end ground connection, connecting node and the same phase of first comparator U1 between 3rd resistor R3 and the 5th resistance R5 End connection；The reverse side of first comparator U1 is equipped with charge and discharge branch, and charge and discharge branch has by second resistance R2 and first capacitor The charging paths that C1 is connected in series, one end second resistance R2 of charging paths are connected with driving plate input pulse signal CMD-H, are another One end (i.e. one end first capacitor C1) ground connection, connecting node and first comparator U1 between second resistance R2 and first capacitor C1 Reverse side be connected；There are also the discharge paths being connected in series by first resistor R1 and first diode D1, electric discharges for charge and discharge branch Branch circuit parallel connection is in the both ends of second resistance R2 and the cathode of first diode D1 is connected with driving plate input pulse signal CMD-H； The output end (through the 6th resistance R6) of first comparator U1 is connected with an input terminal of the second NAND gate U2, the second NAND gate U2 Another input terminal be connected with driving plate input pulse signal CMD-H；The output end of second NAND gate U2 is defeated as driving plate Enter the output end TP-CMD-H of pulse signal CMD-H processing circuit；

IGBT collection emitter voltage state acquisition circuit includes that the in-phase end of the second comparator U3, the second comparator U3 is equipped with by the 7th Resistance R7 and the 8th resistance R8 be connected in series second partial pressure branch, second partial pressure branch both ends respectively with the current collection of IGBT Pole, emitter are connected, and the connecting node between the 7th resistance R7 and the 8th resistance R8 is connect with the in-phase end of the second comparator U3； The reverse side of second comparator U3, which is equipped with, divides branch, third by the third that the 9th resistance R9 and the tenth resistance R10 are connected in series Divide one end connection power supply of branch, the emitter of other end connection IGBT, the company between the 9th resistance R9 and the tenth resistance R10 Node is connect to be connected with the reverse side of the second comparator U3；The output end of second comparator U3 is adopted as IGBT collection emitter voltage state The output end HZ_Vce of collector.