CN210780527U - IGBT drive circuit of wind power converter - Google Patents

Abstract

The utility model discloses an IGBT drive circuit of a wind power converter, which comprises a primary side circuit, an isolation circuit and a secondary side circuit. The primary side circuit comprises a dead zone circuit, an interlock circuit, a protection circuit, a 15V power input filter circuit and a DC/DC circuit. Circuit, the isolation circuit includes a transformer isolation circuit and an optocoupler isolation circuit, and the secondary circuit includes a ±15V drive power supply, a drive circuit and a Vce-sat detection circuit. The utility model can effectively protect the IGBT module, and the primary side circuit of the utility model integrates a dead circuit. Zone circuit, interlock circuit and protection circuit can improve the anti-interference ability and improve the reliability of the drive circuit.

Description

IGBT drive circuit of wind power converter

technical field

The utility model relates to the technical field of driving circuits, in particular to an IGBT driving circuit of a wind power converter.

Background technique

The voltage of the wind power converter system is 690V, and the IGBT module of 1700V is generally used. The high-power IGBT module has a fast switching speed and generates high di/dt and du/dt, which brings EMC electromagnetic interference problems and affects the reliable operation of the converter. Even damage the IGBT module, in order to improve the anti-interference ability, there are the following two solutions:

1) Using optical fiber to transmit control signals, the weak signal of the control circuit and the strong signal of the IGBT module are completely electrically isolated, with strong anti-interference ability and high reliability, but the cost of optical fiber is expensive;

2), usually use special drivers and driving chips, such as wind power special driver 2SD300, which adopts professional modulation and demodulation chips, transmits driving signals through pulse transformers, has strong anti-interference ability and high reliability, and is widely used in wind power converters field.

Although the above two solutions solve the EMC anti-interference problem of wind power converters, the cost is relatively high. The more economical solution is to use optocouplers to achieve electrical isolation, but the primary side of optocouplers generally uses low-voltage circuits (15V or 5V). ), easily disturbed.

In addition, the high di/dt and du/dt generated by the high-power IGBT module during operation will cause false triggering of the upper and lower transistor gates of the IGBT module, resulting in direct connection of the upper and lower transistors of the IGBT module, resulting in short-circuit current. If it is not protected in time, it will lead to The IGBT module is damaged, which seriously affects the normal operation of the converter.

Utility model content

The purpose of the present invention is to provide an IGBT drive circuit of a wind power converter, so as to solve the above-mentioned problems in the background art.

To achieve the above object, the utility model provides the following technical solutions:

The IGBT drive circuit of the wind power converter includes a primary side circuit, an isolation circuit and a secondary side circuit. The primary side circuit includes a dead zone circuit, an interlock circuit, a protection circuit, a 15V power input filter circuit and a DC/DC circuit. The isolation circuit includes a transformer isolation circuit and an optocoupler isolation circuit. The secondary side circuit includes a ±15V drive power supply, a drive circuit and a Vce-sat detection circuit. The Vce-sat detection circuit is respectively connected to the IGBT module, the drive circuit and the optocoupler isolation circuit. The coupling isolation circuit is also connected to the dead zone circuit, the interlock circuit and the protection circuit, and the drive circuit is also connected to the optocoupler isolation circuit and the IGBT module respectively. When the Vce-sat detection circuit detects that the IGBT module has a short-circuit fault or an overcurrent fault, the The isolation circuit transmits the fault signal to the primary side circuit, the primary side circuit blocks the driving signal of the upper and lower tubes of the IGBT module at the same time, and turns off the IGBT module through the optocoupler isolation circuit and the driving circuit.

As a further solution of the present invention: the IGBT module is divided into upper and lower circuits.

As a further solution of the present invention, the dead zone circuit, the interlock circuit and the protection circuit are divided into upper and lower circuits.

As a further solution of the present invention: the optocoupler isolation circuit is divided into upper and lower circuits.

As a further solution of the present invention: the drive circuit is divided into upper and lower circuits.

As a further solution of the present invention, the optocoupler isolation circuit includes a feedback optocoupler and a driving optocoupler.

As a further scheme of the present utility model: the transformer isolation circuit adopts a high-frequency isolation transformer, the secondary side has two independent windings, and outputs two isolated power sources.

Compared with the prior art, the beneficial effects of the utility model are: the utility model can effectively protect the IGBT module, and the primary side circuit of the utility model integrates the dead zone circuit, the interlock circuit and the protection circuit, which can improve the anti-interference ability, Improve the reliability of the drive circuit.

Description of drawings

FIG. 1 is a schematic diagram of a drive circuit of a wind power converter according to the present invention.

FIG. 2 is a specific drive circuit of the wind power converter according to the present invention.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Please refer to Fig. 1-2, Embodiment 1: In the embodiment of the present utility model, the IGBT drive circuit of the wind power converter includes a primary side circuit, an isolation circuit and a secondary side circuit, and the primary side circuit includes a dead zone circuit and an interlock circuit , protection circuit, 15V power input filter circuit and DC/DC circuit, isolation circuit includes transformer isolation circuit and optocoupler isolation circuit, secondary circuit includes ±15V drive power supply, drive circuit and Vce-sat detection circuit.

The primary side circuit includes the dead zone circuit, interlock circuit and protection circuit of the upper and lower tubes;

The function of the dead zone circuit is to realize that the upper and lower tube driving signals have a certain time interval Td. For example, after the upper tube driving signal is turned off, it is necessary to wait for the Td delay before turning on the lower tube driving signal;

The function of the interlock circuit is: the upper and lower tube driving signals cannot be effective at the same time, so as to avoid the generation of the upper and lower tube driving straight-through signals;

The function of the protection circuit is: when there is a fault signal on the secondary side, the protection circuit can turn off the driving signals of the upper and lower tubes at the same time.

The function of the 15V power input filter circuit is to filter the input 15V power supply, maintain the stability of the 15V power supply and reduce EMC interference.

The role of the DC/DC circuit is: 15V power supply high frequency pulse width modulation DC/DC.

The isolation circuit includes: drive optocoupler, feedback optocoupler and isolation transformer.

The function of the driving optocoupler is to transmit the primary side driving signal to the secondary side circuit, and electrically isolate the primary side low voltage side and the secondary side high voltage side.

The function of the feedback optocoupler is to transmit the fault signal of the secondary side to the circuit of the primary side, and electrically isolate the low-voltage side of the primary side and the high-voltage side of the secondary side.

The function of the isolation transformer is to output the driving power of the upper and lower tubes, and electrically isolate the low-voltage side of the primary side and the high-voltage side of the secondary side.

The secondary side circuit includes: ±15V power supply, drive circuit, Vce-sat detection circuit.

The function of the ±15V power supply is to output the drive power recommended by the IGBT module.

The function of the drive circuit is to amplify the secondary side drive signal and push-pull output.

The function of the Vce-sat detection circuit is to detect the desaturation or overcurrent signal of the IGBT module, and the fault signal is fed back to the primary side.

The Vce-sat detection circuit is connected to the IGBT module, the drive circuit and the optocoupler isolation circuit respectively. The optocoupler isolation circuit is also connected to the dead zone circuit, the interlock circuit and the protection circuit. The drive circuit is also connected to the optocoupler isolation circuit and the IGBT module. Vce-sat When the detection circuit detects that the IGBT module has a short-circuit fault or an overcurrent fault, it transmits the fault signal to the primary circuit through the optocoupler isolation circuit. Turn off the IGBT module.

Embodiment 2: On the basis of Embodiment 1, an embodiment circuit of the present utility model is shown in FIG. 2 ,

Among them, the 15V power input filter circuit is a filter composed of L1 and C1, and its main function is to filter the input 15V power supply and reduce switching noise and electromagnetic interference.

The DC/DC circuit is composed of Q1, Q2, T1 to form a push-pull circuit, and Q1 and Q2 are composed of transistors. T1 is a high-frequency isolation transformer, and its secondary side has two independent windings, which output two isolated power supplies:

The top-tube isolated power supply includes:

D7 and C4 form a diode rectifier circuit and output -15V_SH power supply;

D8 and C5 form a diode rectifier circuit and output +15V_SH power supply;

Among them, the lower tube isolated power supply includes:

D9 and C6 form a diode rectifier circuit and output -15V_SL power supply;

D11 and C7 form a diode rectifier circuit and output +15V_SL power supply;

The upper tube dead zone circuit and interlock circuit are composed of V1, V2, R2, C2, D2, the lower tube dead zone circuit and interlock circuit are composed of V3, V4, R3, C3, D3, and the protection circuit includes D5, V5, D6 , V6 composition.

The PWM_H signal is the input signal of the upper tube, and the PWM_L signal is the input signal of the lower tube;

When the PWM_L signal is at a high level, C2 discharges quickly through D2, and when the PWM_L signal is at a low level, C2 is charged through R2, and R2 and C2 form a dead zone delay Td.

When the PWM_H signal is at a high level, C3 is rapidly discharged through D3, and when the PWM_L signal is at a low level, C3 is charged through R3, and R3 and C3 form a dead zone delay Td.

Among them, the V1 input adopts CMOS Schmitt NAND gate, which can improve the threshold voltage of the input signal and improve the anti-interference ability of the signal.

The upper tube drive circuit is composed of R11, Q3, Q4, R8 to form a push-pull amplifier circuit, which amplifies the optocoupler output signal U2_OUT signal, and the upper tube drive signal DRV_H is directly connected to the upper tube gate HG of the IGBT module to meet the IGBT module's drive peak current. demand.

The lower tube drive circuit consists of R17, Q5, Q6, R18 to form a push-pull amplifier circuit, which amplifies the optocoupler output signal U4_OUT signal, and the lower tube drive signal DRV_L is directly connected to the lower tube gate LG of the IGBT module, which meets the IGBT module's drive peak current. demand.

The upper tube Vce-sat detection circuit consists of R9, D11, R10 to form a Vce-sat sampling circuit:

，采样信号VCE_H，R13和R14构成分压电路(通过R13和 R14设定保护值)

，比较信号COMP_H，通过VCE_H与COMP_H的比较实现 Vce饱和压降的检测，并输出故障信号FAULT_H：当VCE_H小于COMP_H，FAULT_H为高电平，正 常状态；当VCE_H大于COMP_H，FAULT_H为低电平，报故障状态; When the drive signal DRV_H is at a high level (15V), the voltage dividing principle of the voltage drop Vce-sat through the resistor and the IGBT module turn-on voltage:

, the sampling signal VCE_H, R13 and R14 form a voltage divider circuit (set the protection value through R13 and R14)

, compare signal COMP_H, realize Vce saturation voltage drop detection by comparing VCE_H and COMP_H, and output fault signal FAULT_H: when VCE_H is less than COMP_H, FAULT_H is high level, normal state; when VCE_H is greater than COMP_H, FAULT_H is low level, report fault status;

，不检测故障，Vce-sat检测被禁止，该状态下 不检测Vce，原因是IGBT封锁状态Vce电压为关断电压; When the drive signal DRV_L is at a low level (-15V), the voltage division principle of the voltage drop Vce-sat through the resistor and the IGBT module turn-on voltage:

, do not detect faults, Vce-sat detection is prohibited, Vce is not detected in this state, the reason is that the IGBT blocking state Vce voltage is the off voltage;

The lower tube Vce-sat detection circuit consists of R15, D12, R16 to form a Vce-sat sampling circuit:

，采样信号VCE_H，R6和R7构成分压电路(通过R6和R7 设定保护值)

，比较信号COMP_H，通过VCE_H与COMP_H的比较实现Vce饱 和压降的检测，并输出故障信号FAULT_H：当VCE_H小于COMP_H，FAULT_H为高电平，正常状 态；当VCE_H大于COMP_H，FAULT_H为低电平，报故障状态; When the drive signal DRV_L is at a high level (15V), the voltage division principle of Vce-sat through the resistor and the conduction voltage drop of the IGBT module:

, the sampling signal VCE_H, R6 and R7 form a voltage divider circuit (set the protection value through R6 and R7)

, compare signal COMP_H, realize Vce saturation voltage drop detection by comparing VCE_H and COMP_H, and output fault signal FAULT_H: when VCE_H is less than COMP_H, FAULT_H is high level, normal state; when VCE_H is greater than COMP_H, FAULT_H is low level, report fault status;

，不检测故障，Vce-sat检测被禁止，该状态下 不检测Vce，原因是IGBT封锁状态Vce电压为关断电压; When the drive signal DRV_H is at a low level (-15V), the principle of dividing the voltage Vce-sat through the resistor and the conduction voltage drop of the IGBT module:

, do not detect faults, Vce-sat detection is prohibited, Vce is not detected in this state, the reason is that the IGBT blocking state Vce voltage is the off voltage;

When FAULT_H is low level, the optocoupler U1_OUT outputs high level, after D5 and V5, the fault signal FAULT_P is low level, which blocks the drive signal.

The lower tube Vce-sat detection circuit consists of R15, D12, R16 to form a Vce-sat sampling circuit, the sampling signals VCE_L, R13 and R14 form a voltage divider circuit (the protection value is set by R13 and R14), the comparison signal COMP_L, through VCE_L and COMP_L The comparison of Vce-sat realizes the detection of Vce-sat, and outputs the fault signal FAULT_L. When FAULT_L is low, the optocoupler U3_OUT outputs high level. After D6 and V6, the fault signal FAULT_P is low, and the driving signal is blocked.

The logical relationship of the upper tube signal is:

Among them, V1_OUT is the output signal of the V1 NAND gate, and U2_OUT is the output signal of the optocoupler U2 (the figure above corresponds to the 7-pin of U2)

Dead zone logic description: When mode 2 transitions to mode 3, at least Td should be delayed in the middle

Interlock logic description: When PWM_H and PWM_L are high at the same time, the U2 output signal is low, which avoids the direct short-circuit of the upper and lower tubes of the IGBT module due to EMC electromagnetic interference and other factors, and improves the anti-interference of the primary circuit. ability to effectively protect the IGBT module.

In the fault state, PWM_H and PWM_L are at any level, and the drive output signal DRV_H is at a low level, and the IGBT module is turned off in time;

The logical relationship of the down pipe signal is:

Among them, V3_OUT is the output signal of the V3 NAND gate, and U4_OUT is the output signal of the optocoupler U4 (the figure above corresponds to pin 7 of U4)

Dead zone logic description: When mode 2 transitions to mode 3, at least Td should be delayed in the middle

Interlock logic description: When PWM_H and PWM_L are high at the same time, the U4 output signal is low, which avoids the direct short-circuit of the upper and lower tubes of the IGBT module due to EMC electromagnetic interference and other factors, and improves the anti-interference of the primary circuit. ability to effectively protect the IGBT module.

In the fault state, PWM_H and PWM_L are at any level, and the drive output signal DRV_L is at a low level, which turns off the IGBT module in time.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention may be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments are to be considered in all respects as exemplary and not restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that the All changes within the meaning and range of the required equivalents are embraced within the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (5)

1. The IGBT drive circuit of the wind power converter comprises a primary side circuit, an isolation circuit and a secondary side circuit, wherein the primary side circuit comprises a dead zone circuit, an interlock circuit, a protection circuit, a 15V power input filter circuit and DC/DC circuit, the isolation circuit includes a transformer isolation circuit and an optocoupler isolation circuit, the secondary circuit includes a ±15V drive power supply, a drive circuit and a Vce-sat detection circuit, and the Vce-sat detection circuit is respectively connected to the IGBT module and the drive circuit. And the optocoupler isolation circuit, the optocoupler isolation circuit is also connected to the dead zone circuit, the interlock circuit and the protection circuit, and the drive circuit is also connected to the optocoupler isolation circuit and the IGBT module respectively. 2 . The IGBT drive circuit of a wind power converter according to claim 1 , wherein the IGBT module is divided into upper and lower circuits. 3 . 3 . The IGBT drive circuit of the wind power converter according to claim 2 , wherein the dead zone circuit, the interlock circuit and the protection circuit are divided into upper and lower circuits. 4 . 4 . The IGBT drive circuit of a wind power converter according to claim 1 , wherein the optocoupler isolation circuit comprises a feedback optocoupler and a drive optocoupler. 5 . 5 . The IGBT drive circuit of a wind power converter according to claim 1 , wherein the transformer isolation circuit adopts a high-frequency isolation transformer, the secondary side has two independent windings, and outputs two isolated power sources. 6 .

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