CN217693065U

CN217693065U - Realize high-power IBGT drive isolation circuit

Info

Publication number: CN217693065U
Application number: CN202221303417.1U
Authority: CN
Inventors: 刘豹; 苗兰芳
Original assignee: Shinva Medical Instrument Co Ltd
Current assignee: Shinva Medical Instrument Co Ltd
Priority date: 2022-05-27
Filing date: 2022-05-27
Publication date: 2022-10-28
Anticipated expiration: 2032-05-27

Abstract

The utility model provides a realize high-power IBGT drive isolation circuit belongs to dc-to-ac converter drive field. The high-power IBGT circuit isolation circuit comprises an isolation module, wherein the isolation module is connected with an NPN triode amplification circuit and a PNP triode amplification circuit, the NPN triode amplification circuit and the PNP triode amplification circuit are connected with a high-power IBGT, and an isolation power supply supplies power for the circuit. After the isolation module outputs the driving current, the driving current is amplified through the NPN triode amplifying circuit and the PNP triode amplifying circuit, so that the driving current with a large current value is output to drive the high-power IBGT, the high-power IBGT is switched off quickly, the IBGT fault can be avoided, the service life of the IBGT is prolonged, the defects of an isolation optocoupler and the IBGT driving isolation chip driving current are effectively overcome, and the high-power IBGT driving isolation module is suitable for driving isolation of the high-power IBGT.

Description

Realize high-power IBGT drive isolation circuit

Technical Field

The utility model belongs to dc-to-ac converter drive field specifically is a realize high-power IBGT drive isolation circuit.

Background

The high-power IBGT driving isolation circuit is mainly applied to the driving of the IBGT of a high-power inverter, and the IBGT has an electrical characteristic that the grid charge, the input capacitance and the reverse transmission capacitance are increased along with the increase of the maximum rated voltage and the maximum rated current of the IBGT due to the manufacturing process. This characteristic causes the capacitance between the gate and emitter of the high power IBGT to be large, which will sink the drive current during the IBGT commutation.

Most of the existing technologies adopt an isolation optocoupler or an IBGT drive isolation chip to provide drive current, however, the drive current provided by the isolation optocoupler or the IBGT drive isolation chip is small, so the drive capability is limited, the rise speed of the drive voltage is relatively slow, the commutation time of the high-power IBGT is prolonged, the IBGT generates heat seriously, the performance fault of the IBGT is caused, and the service life of the IBGT is influenced.

Disclosure of Invention

An object of the utility model is to provide a realize high-power IBGT drive isolation circuit, through introducing NPN triode amplifier circuit and the PNP triode amplifier circuit of push-pull output, realize keeping apart the drive of high-power IBGT to solve because keep apart opto-coupler or IBGT drive and keep apart the limited problem that leads to IBGT trouble, influence its life that makes the high-power IBGT commutation time extension of chip driving force.

The method is realized by adopting the following technical scheme:

the high-power IBGT driving isolation circuit comprises an isolation module, wherein the isolation module is connected with an NPN triode amplification circuit and a PNP triode amplification circuit, the NPN triode amplification circuit and the PNP triode amplification circuit are connected with the high-power IBGT, and an isolation power supply supplies power to the circuit. After the isolation module outputs the driving current, the driving current is amplified through the NPN triode amplifying circuit and the PNP triode amplifying circuit, the driving current above 3A is output to the high-power IBGT after amplification, and the high-power IBGT is quickly switched on and off in the PWM trigger driving circuit, so that the reversing time of the high-power IBGT is shortened, and the heat productivity in the process is reduced; the isolation power supply provides the system with isolated positive voltage power supply, negative voltage power supply and reference voltage zero point.

Furthermore, a filter capacitor, a TVS transient suppression diode and a discharge resistor are connected in parallel between the grid and the source of the high-power IBGT. The filter capacitor can filter the PWM signal of the input circuit, and can prevent the interference of higher harmonics generated in the switching-on and switching-off process of the high-power IGBT; the TVS transient suppression diode can quickly release peak voltage generated in the switching-on and switching-off process of the high-power IGBT, so that a protection effect is achieved; the dump resistor can absorb the residual voltage generated in the PWM signal reversing process in time, and the rapid switching-on and switching-off of the high-power IGBT are realized in an auxiliary manner.

Further, the NPN triode amplifying circuit comprises an NPN triode and a current-limiting resistor two, and the PNP triode amplifying circuit comprises a PNP triode and a current-limiting resistor three. The NPN type triode and the PNP type triode can amplify the driving signal output by the isolation module, and the driving current of the high-power IGBT can be changed by adjusting the resistance value of the current-limiting resistor.

Furthermore, the isolation module adopts an isolation optocoupler or an IBGT drive isolation chip. The isolation optical coupler isolation is to adopt an optical coupler for isolation, and the driving current of a general isolation optical coupler is 5-20 mA and 50mA at most; the IBGT drive isolation chip is an integrated drive chip with protection and isolation functions, and the IBGT drive isolation chips commonly used in the market have certain limitation and are mostly only suitable for low-power IBGT drive isolation.

Furthermore, the ground of the output side of the isolation module is connected with the ground of the output side of the isolation power supply in a common mode, and the driving signal output end of the isolation module is connected with the + Vo end of the output side of the isolation power supply through a pull-up resistor. The + Vo terminal of the isolated power supply provides an isolated positive voltage supply for the system.

Furthermore, the driving signal output end of the isolation module is connected with the base stages of the NPN type triode and the PNP type triode through a first current limiting resistor. The current of the bases of the NPN type triode and the PNP type triode can be changed by adjusting the resistance value of the first current limiting resistor.

Furthermore, a collector of the NPN type triode is connected with a + Vo end of the output side of the isolation power supply, and an emitter of the NPN type triode is connected with a grid electrode of the high-power IBGT through a second current-limiting resistor. The + Vo end of the isolation power supply provides an isolated positive voltage power supply for the system, and the gate driving current of the high-power IGBT can be changed by adjusting the resistance value of the current-limiting resistor II.

Furthermore, the collector of the PNP type triode is connected with the-Vo end of the output side of the isolation power supply, and the emitter of the PNP type triode is connected with the grid of the high-power IBGT through a current-limiting resistor III. the-Vo end of the isolation power supply provides an isolated negative voltage power supply for the system, and the gate driving current of the high-power IGBT can be changed by adjusting the resistance value of the current-limiting resistor III.

The utility model discloses the beneficial effect who realizes is:

(1) The NPN triode amplifying circuit and the PNP triode amplifying circuit are introduced into the driving isolation circuit to amplify the driving current of the isolation optocoupler or the IBGT driving isolation chip, so that the circuit can drive the high-power IBGT; compare in the circuit that the chip provided drive current is kept apart in simple use isolation opto-coupler or IBGT drive, the utility model discloses the drive current of big current value can be exported, the fast switch who realizes high-power IBGT is disconnected, consequently can shorten high-power IBGT's switching-over time, reduce the calorific capacity of switching-over in-process to avoid IBGT trouble, prolong its life.

(2) Furthermore, a filter capacitor, a TVS transient suppression diode and a discharge resistor are additionally arranged, so that the functions of filtering, protecting and assisting in realizing rapid switching on and switching off are respectively performed on the circuit.

Drawings

Fig. 1 is a schematic circuit diagram of an embodiment of the present invention;

in the figure: u1 and an isolation module; u2, an isolated power supply; r1 and resistance; r2, a pull-up resistor; r3, a first current limiting resistor; r4, a second current limiting resistor; r5 and a current-limiting resistor III; r6, discharging a resistor; q1, NPN type triode; q2, PNP type triode; q3, high-power IBGT; CR1, TVS transient suppression diode; c1, a filter capacitor.

Detailed Description

For the purpose of clarity, the embodiments of the present invention will be further described with reference to the accompanying drawings:

as shown in fig. 1, the high-power IBGT driving isolation circuit includes an isolation module U1, the isolation module U1 is connected to an NPN transistor amplification circuit and a PNP transistor amplification circuit, the NPN transistor amplification circuit and the PNP transistor amplification circuit are connected to a high-power IBGTQ3, and an isolation power supply U2 supplies power to the circuit.

The Vin end of the isolation power supply U2 is connected with the direct-current power supply, the GND end is grounded, the-Vo end provides an isolated negative voltage power supply for the system, the + Vo end provides an isolated positive voltage power supply for the system, and the 0V end provides an isolated reference voltage zero point 0V for the system; the isolation module U1 adopts an isolation optocoupler or an IBGT to drive an isolation chip, an anode A end of the isolation module U1 is connected with a PWM signal, a cathode C end is grounded through a resistor R1, a VCC end is connected with a + Vo end of an isolation power supply U2 providing a positive voltage power supply, a GND end is connected with a 0V end of the isolation power supply U2 providing a reference voltage zero point, a collector VO end is connected with a + Vo end of the isolation power supply U2 providing the positive voltage power supply through a pull-up resistor R2, and the collector VO end is connected with an NPN type triode Q1 and a base electrode of a PNP type triode Q2 through a current-limiting resistor R3; the base electrode of the NPN type triode Q1 is connected with the collector VO end of the isolation module U1 through a first current-limiting resistor R3, the collector electrode is connected with the + VO end of an isolation power supply U2 which provides a positive voltage power supply, and the emitter electrode is connected with the grid electrode of the high-power IGBTQ3 through a second current-limiting resistor R4; the base electrode of the PNP type triode Q2 is connected with the collector electrode VO end of the isolation module U1 through a current-limiting resistor I R3, the collector electrode is connected with the-VO end of an isolation power supply U2 for providing a negative voltage power supply, and the emitter electrode is connected with the grid electrode of the high-power IGBTQ3 through a current-limiting resistor III R5; the TVS transient suppression diode CR1, the filter capacitor C1 and the discharge resistor R6 are connected in parallel and then connected between the grid of the high-power IGBTQ3 and the transmitter.

The working process of the utility model is as follows:

when a PWM signal of the input circuit is in a low level, an optical coupler of the isolation module U1 is cut off, a collector VO end of the isolation module U1 is connected with a + VO end of the isolation power supply U2 through a resistor R2 to output a high level to the outside, at the moment, the base current of the NPN type triode Q1 is changed by adjusting the resistance value of a current-limiting resistor I R3, the NPN type triode Q1 amplifies a driving signal output by the collector VO end of the isolation module U1, and then the gate driving current of the high-power IGBTQ3 is changed by adjusting the resistance value of a current-limiting resistor II R4; through the process, the NPN type triode Q1 amplifies the driving signal, so that the high-power IGBTQ3 is quickly opened.

When a PWM signal of an input circuit is in a high level, an optical coupler of an isolation module U1 is conducted, a collector VO end of the isolation module U1 is connected with a 0V end of an isolation power supply U2 in a conducting mode through the optical coupler to output low voltage to the outside, the base current of a PNP type triode Q2 is changed by adjusting the resistance value of a current limiting resistor R3, the PNP type triode Q2 amplifies a driving signal output by the collector VO end of the isolation module U1, and then the grid driving current of a high-power IGBTQ3 is changed by adjusting the resistance value of a current limiting resistor R5; through the process, the PNP type triode Q2 amplifies the driving signal, so that the high-power IGBTQ3 is quickly turned off.

In the process of realizing the rapid on-off of the high-power IBGTQ3, the filter capacitor C1 filters a PWM signal of an input circuit, so that the interference of higher harmonics generated in the on-off process of the high-power IBGTQ3 is prevented; the discharge resistor R6 can absorb residual voltage generated in the PWM signal reversing process in time, and the high-power IBGTQ3 is switched on and off quickly in an auxiliary manner; the TVS transient suppression diode CR1 can quickly discharge spike voltage generated in the switching-on and switching-off process of the high-power IBGTQ3, so that the high-power IBGTQ3 is protected.

Of course, the above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and the technical field of the present invention is equivalent to the changes and improvements made in the actual range of the present invention, which should be attributed to the patent coverage of the present invention.

Claims

1. A drive isolation circuit for realizing high-power IBGT is characterized in that: the circuit comprises an isolation module U1, wherein the isolation module U1 is connected with an NPN triode amplification circuit and a PNP triode amplification circuit, the NPN triode amplification circuit and the PNP triode amplification circuit are connected with a high-power IBGTQ3, and an isolation power supply U2 supplies power for the circuit.

2. The circuit according to claim 1, wherein the IBGT drive isolation circuit for high power is characterized in that: and a filter capacitor C1, a TVS transient suppression diode CR1 and a discharge resistor R6 are connected in parallel between the grid and the source of the high-power IBGTQ 3.

3. The circuit according to claim 1, wherein the IBGT drive isolation circuit for high power is characterized in that: the NPN triode amplifying circuit comprises an NPN triode Q1 and a current-limiting resistor two R4, and the PNP triode amplifying circuit comprises a PNP triode Q2 and a current-limiting resistor three R5.

4. The circuit according to claim 1, wherein the IBGT drive isolation circuit for high power is characterized in that: the isolation module U1 adopts an isolation optocoupler or an IBGT drive isolation chip.

5. The circuit according to claim 1, wherein the IBGT drive isolation circuit for high power is characterized in that: the ground of the output side of the isolation module U1 is connected with the ground of the output side of the isolation power supply U2 in a common ground mode, and the driving signal output end of the isolation module U1 is connected with the + Vo end of the output side of the isolation power supply U2 through a pull-up resistor R2.

6. A circuit for implementing high power IBGT drive isolation according to claim 3, wherein: and the driving signal output end of the isolation module U1 is connected with the base stages of the NPN type triode Q1 and the PNP type triode Q2 through a current-limiting resistor R3.

7. A circuit for implementing high power IBGT drive isolation according to claim 3, wherein: the collector of the NPN type triode Q1 is connected with the + Vo end of the output side of the isolation power supply U2, and the emitter of the NPN type triode Q1 is connected with the grid of the high-power IBGTQ3 through the current-limiting resistor II R4.

8. A circuit for implementing high power IBGT drive isolation according to claim 3, wherein: the collector of the PNP triode Q2 is connected with the-Vo end of the output side of the isolation power supply U2, and the emitter of the PNP triode Q2 is connected with the grid of the high-power IBGTQ3 through a current-limiting resistor three R5.