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Passive protection circuit of igbt

A passive protection and circuit technology, applied in emergency protection circuit devices, emergency protection circuit devices for limiting overcurrent/overvoltage, circuit devices, etc. Ground use and other issues to achieve the effect of reducing operating current and ensuring safety

Active Publication Date: 2019-03-29
ZONECHARGE (SHENZHEN) WIRELESS POWER TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Therefore, high-power IGBTs usually require over-current protection. In most cases, the over-current protection circuit is added to the IGBT drive amplifier circuit or module. Users usually do not understand its working principle and can only use it mechanically, which lacks flexibility. What's more serious is that once the IGBT is damaged, the driving circuit is usually damaged together. That is to say, how to protect the IGBT if the protection circuit itself is not guaranteed.

Method used

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  • Passive protection circuit of igbt
  • Passive protection circuit of igbt
  • Passive protection circuit of igbt

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] attached figure 1 Among them, the resistor R2, the voltage regulator DW2, the base b and the emitter e of the transistor Q1 form a reference voltage circuit, the diode D1 and the voltage regulator DW1 form the Vce sampling circuit of the IGBT, and the transistor Q1 and the resistor R4 form a switch protection circuit.

[0019] The connection principle of this circuit and IGBT is as attached image 3 , P1 is the driving signal of the IGBT, usually between 10-18V, it is used as a power supply in the protection circuit, and there are two ways of current flow: one is from the resistance R2---DW1---D1--- The CE junction of the IGBT, and the other is from the be junction of the resistor R2---DW2---the transistor Q1. These two paths will not be turned on at the same time, and only one path will be turned on at the same time. When the IGBT is working normally, that is, the CE of the IGBT When the voltage drop Vce on the junction does not reach its inherent saturation voltage, ...

Embodiment 2

[0028] attached figure 2 It is a passive protection circuit diagram of an IGBT using a photocoupler as feedback. In the figure, the resistor R2, the voltage regulator DW2, the base b and the emitter e of the transistor Q1 form a reference voltage circuit, and the diode D1 and the voltage regulator DW1 form an IGBT. The Vce sampling circuit, transistor Q1, resistor R4, and photocoupler OP1 form a switch feedback protection circuit, and its working principle is the same as that of the attached figure 1 Basically the same, the difference is that a photocoupler is added to the protection output, which is used to isolate the high voltage of the IGBT. When the IGBT is saturated, Vce reaches or exceeds its inherent saturation voltage, Q1 is turned on, and the photocoupler in the photocoupler The light-emitting tube lights up, and the isolated photosensitive tube is turned on, that is, the output terminals M and N are turned on.

[0029] The application of this circuit is as attache...

Embodiment 3

[0031] attached Figure 4 , the protection circuit feeds back the protection signal to different low-voltage control circuits, such as signal sources, signal input circuits or MCU management circuits, through the output terminal of the optocoupler OP1.

[0032] attached Figure 6a , Figure 6b It is the PWM signal comparison diagram of the IGBT gate, attached Figure 6a It is a normal PWM waveform, indicating that the IGBT is working in an unsaturated state, that is, a normal state. Attached Figure 6b For the PWM waveform in the protection state, that is, the PWM waveform in the saturation state, this waveform is cut into three square waves with a small duty cycle, and the working time of the IGBT is reduced, so that the current flowing through the IGBT is clamped at the saturation current Below, the IGBT is protected, and at the same time it is in a working state, that is, it is in a non-stop state.

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PUM

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Abstract

The invention relates to a passive protection circuit of an insulated gate bipolar transistor (IGBT), and belongs to the field of an application power supply. A driving signal of a driving circuit is used as a power supply, the passive protection circuit comprises a reference voltage circuit, a Vce sampling circuit and a protection circuit, wherein the reference voltage circuit comprises a resistor, a voltage stabilization tube and a BE junction of a triode, a positive electrode of the driving signal, a resistor, a positive electrode of the voltage stabilization tube, a negative electrode of the voltage stabilization tube, the BE junction of the triode and driving signal ground are in electrical connection, the Vce sampling circuit comprises a diode and a voltage stabilization tube, a C pole of the IGBT, a positive electrode of the diode, a negative electrode of the diode, a negative electrode of the voltage stabilization tube, a positive electrode of the voltage stabilization tube and the positive electrode of the voltage stabilization tube in the reference voltage circuit are in electrical connection, the protection circuit comprises a resistor and an N-type triode, and the resistor is an electronic static discharge (ESD) protection loop of the triode. In the passive protection circuit, an external auxiliary power supply is not additionally arranged, pulse width modulation (PWM) with relatively large duty ratio is partitioned into square wave signals with relatively small duty ratio, the IGBT works in a large-current saturation state for a long time, the working current of the IGBT is reduced on the premise of no stop, and the safety of the IGBT is ensured.

Description

technical field [0001] The invention relates to a passive protection circuit of an IGBT, which belongs to the field of applied power supplies. Background technique [0002] IGBT is the abbreviation of ISOLATED GATE BIPOLAR TRANSISTOR. It is a commonly used power element. It is a voltage-controlled semiconductor device composed of a bipolar transistor BJT and an insulated gate field effect transistor MOSFET. It has It has the characteristics of high input impedance and small conduction voltage drop. Therefore, it is often used in occasions where large currents work, such as motor drives, switching currents, and frequency converters. [0003] This composite device has three poles: gate G, emitter E, and collector C. As long as an appropriate gate-emitter voltage is provided, that is, Vge, the emitter E and collector C are turned on, and the current passes through the two poles. Due to different production materials and processes, the Vce of each IGBT is different. Vce is not ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02H9/02
CPCH02H9/02
Inventor 朱斯忠徐宝华
Owner ZONECHARGE (SHENZHEN) WIRELESS POWER TECH CO LTD