CN211456993U

CN211456993U - High-reliability direct connection prevention protection circuit driven by IGBT/MOSFET optocouplers

Info

Publication number: CN211456993U
Application number: CN202020382005.6U
Authority: CN
Inventors: 张德宽; 董兆辉
Original assignee: Tianjin Fangyuan Electric Equipment Co ltd
Current assignee: Tianjin Fangyuan Electric Equipment Co ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2020-09-08
Anticipated expiration: 2030-03-24

Abstract

The utility model relates to a direct protection circuit is prevented in drive of high reliability IGBT MOSFET opto-coupler, its technical characterstic is: the signal interlocking device comprises a signal amplification module, a rectifying circuit, a dead time adjusting circuit and a signal interlocking output module, wherein the signal amplification module is connected with the signal interlocking output module through the rectifying circuit and the dead time adjusting circuit, and the signal interlocking output module is composed of two optical couplers. The utility model relates to a rationally, can effectively improve the reliability of drive IGBT, MOSFET, solve IGBT, MOSFET's through problem effectively, reduce driven cost, can extensively be arranged in IGBT, the various opto-coupler driven half bridge arm of MOSFET, H bridge arm, multi-bridge arm to all there is very good effect at each power level.

Description

High-reliability direct connection prevention protection circuit driven by IGBT/MOSFET optocouplers

Technical Field

The utility model belongs to the technical field of power switch, especially, direct protection circuit is prevented in drive of high reliability IGBT MOSFET opto-coupler.

Background

Currently, in industrial production, IGBT and MOSFET devices are widely used for buck and boost circuits, frequency converters, active front ends, EPS, and the like. The IGBT and the MOSFET can be used in various optical coupler driven half bridge arms, H bridge arms and multi-bridge arms, driving signals of an upper pipe and a lower pipe of the equipment are not protected by interlocking generally, and are easily interfered by the outside or electromagnetic interference of self large current, surrounding electromagnetic wave energy is absorbed, the upper pipe and the lower pipe are conducted at the same time, and the upper pipe and the lower pipe are in direct short circuit to cause damage of the device. The existing protection circuits usually adopt a gate circuit interlocking circuit, and have the problems of complex circuit structure, high cost, more fault points and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the not enough of prior art, provide a stable performance, the high and low cost's of reliability IGBT/MOSFET opto-coupler drive prevents direct protection circuit.

The utility model provides a its technical problem take following technical scheme to realize:

a high-reliability direct connection prevention protection circuit driven by IGBT/MOSFET optical couplers comprises a signal amplification module, a rectification circuit, a dead time adjusting circuit and a signal interlocking output module, wherein the signal amplification module is connected with the signal interlocking output module through the rectification circuit and the dead time adjusting circuit, and the signal interlocking output module is composed of two optical couplers.

The rectification circuit comprises two resistors, the dead time adjusting circuit comprises a capacitor, the signal amplification module comprises two output ends, a first output end of the signal amplification module is connected with a diode anode of the first optical coupler and a diode cathode of the second optical coupler through the first resistor, a second output end of the signal amplification module is connected with a diode cathode of the first optical coupler and a diode anode of the second optical coupler through the second resistor, and the capacitor is connected between the two resistors in parallel.

The signal amplification module is a same-direction signal amplifier.

The utility model has the advantages that:

1. the utility model discloses a drive opto-coupler adopts the reversal mode, has both played the reverse breakdown overvoltage protection's of opto-coupler left and right sides, makes the possibility that top tube and low tube did not switch on simultaneously, has increased the reliability.

2. The utility model discloses a two way drive signal of top tube and low tube are simultaneously through drive chip output, and the low level is effective, and the high level is the off-state simultaneously, and this method can prevent the entering back level of common mode malfunction signal.

3. The utility model discloses a dead time can be adjusted to time inertia link, and is both simple from the effect, has solved IGBT, MOSFET's through problem effectively.

4. The utility model relates to a rationally, can effectively improve the reliability of drive IGBT, MOSFET, reduce driven cost, can extensively be arranged in IGBT, the various opto-coupler driven half bridge arm of MOSFET, H bridge arm, multi-bridge arm to all there is very good effect at each power level.

Drawings

Fig. 1 is a block diagram of a control circuit of the present invention;

fig. 2 is a wiring diagram of the host interface of the present invention.

Detailed Description

The embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A high-reliability IGBT/MOSFET optical coupling drive direct connection prevention protection circuit is shown in figures 1 and 2 and comprises a signal amplification module, a rectification circuit, a dead time adjusting circuit and a signal interlocking output module, wherein the signal amplification module is connected with the signal interlocking output module through the rectification circuit and the dead time adjusting circuit. The signal amplification module adopts a homodromous signal amplifier chip (U1), the rectification circuit is composed of two resistors, the dead time adjusting circuit is composed of a capacitor, and the signal interlocking circuit comprises two optical coupler chips (U2 and U3). The following are described separately:

the signal amplification module adopts a same-direction signal amplifier (U1), and in the embodiment, the same-direction signal amplifier (U1) adopts a 74HC244D chip. The same-direction signal amplifier amplifies the drive signals of the DSP and complementarily drives the drive signals of the upper tube and the lower tube, so that the influence on the rear stage caused by interference signals and false operation signals of the front stage of the signals is avoided. The two outputs are VIN1 and VIN 2.

The rectifying circuit comprises a resistor R1 and a resistor R2. One end of the resistor R1 is connected with a VIN1 end of the equidirectional signal amplifier (U1), the other end of the resistor R1 is connected with a diode anode of the first optical coupler (U2) and a diode cathode of the second optical coupler (U3), one end of the resistor R2 is connected with a VIN2 end of the equidirectional signal amplifier (U1), and the other end of the resistor R2 is connected with a diode cathode of the first optical coupler (U2) and a diode anode of the second optical coupler (U3). The function of the rectification circuit is as follows: the maximum conduction current of the dead time adjusting circuit and the signal interlocking output modules (U2 and U3) is limited, overcurrent damage caused by overlarge current of the U1 and the U2 is prevented, the problem of line impedance difference caused by difference of upper tube and lower tube driving signals and circuit board wiring and the like can be effectively prevented by adopting a double-resistor mode, and meanwhile, damage of rear-stage high-voltage breakdown to the front-stage U1 can be prevented.

The dead time adjusting circuit comprises a capacitor C1, and the capacitor C1 is connected between a resistor R1 and a resistor R2 in parallel. Because the capacitor C1 is connected in the rectifying circuit, the dead time adjustment and the filtering function are realized. When VIN1 is at a low level and VIN2 is at a high level, the signal output charges a capacitor C1 through R2 and R1, and VIN2 is at a low level when the level is reversed; when VIN1 is at high level, the charge in the C1 capacitor is first released and then charged, the charge release process is dead time, the dead time can be changed by changing the capacitance value, and C1 also plays a role in filtering.

The signal interlock output module comprises two optical coupler chips (U2, U3), and in the embodiment, the optical coupler chips adopt M57962AL chips. The signal interlocking output module enables the front stage inputs of the driving optical coupler of the upper pipe and the lower pipe to be reversely connected in parallel, the front stage of the optical coupler is a light emitting diode, the interlocking effect is achieved after the front stage inputs of the driving optical coupler are reversely connected in parallel, and meanwhile the problem of reverse voltage breakdown of the front stage of the optical coupler can be solved.

The above is the utility model discloses an theory of operation explains, adjusts C1's size in practical application, can adjust dead time, and U1 will have certain driving force to drive U2, U3 simultaneously.

The utility model discloses the nothing is mentioned the part and is applicable to prior art.

It should be emphasized that the embodiments described herein are illustrative and not restrictive, and thus the present invention includes but is not limited to the embodiments described in the detailed description, as well as other embodiments derived from the technical solutions of the present invention by those skilled in the art, which also belong to the scope of the present invention.

Claims

1. The utility model provides a high reliability IGBT/MOSFET opto-coupler drive prevents direct protection circuit which characterized in that: the signal interlocking device comprises a signal amplification module, a rectifying circuit, a dead time adjusting circuit and a signal interlocking output module, wherein the signal amplification module is connected with the signal interlocking output module through the rectifying circuit and the dead time adjusting circuit, and the signal interlocking output module is composed of two optical couplers.

2. The high-reliability IGBT/MOSFET optical coupling driving anti-shoot-through protection circuit according to claim 1, wherein: the rectification circuit comprises two resistors, the dead time adjusting circuit comprises a capacitor, the signal amplification module comprises two output ends, a first output end of the signal amplification module is connected with a diode anode of the first optical coupler and a diode cathode of the second optical coupler through the first resistor, a second output end of the signal amplification module is connected with a diode cathode of the first optical coupler and a diode anode of the second optical coupler through the second resistor, and the capacitor is connected between the two resistors in parallel.

3. The high-reliability IGBT/MOSFET optical coupling driving anti-shoot-through protection circuit according to claim 1, wherein: the signal amplification module is a same-direction signal amplifier.