An igbt high voltage drive overcurrent and overvoltage protection circuit

Abstract

The invention discloses a high-voltage driving overcurrent and overvoltage protection circuit for IGBT, which belongs to the technical field of electronic circuits. The circuit includes an IGBT, an IGBT drive module, a feedback controller, a current detection module, and a voltage detection module. The invention uses a current detection module to prevent IGBT overcurrent and short circuit, especially when a large current caused by a short circuit flows, the self-shutoff design can quickly reduce the voltage difference between the IGBT gate and emitter, and prevent the time for large current to pass through the IGBT too long. The voltage detection module can prevent the IGBT from overvoltage by using a clamp circuit. When the TVS tube is broken down, the feedback voltage and current can be input to the IGBT gate to help the IGBT to open quickly, and the overvoltage protection can be realized in a short time. The invention has a simple structure, and can adjust the resistance value of the sampling resistor, the voltage dividing resistor or the voltage stabilizing tube as required, so as to meet different application requirements.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to a high-voltage driving overcurrent and overvoltage protection circuit for IGBT. Background technique [0002] Insulated gate bipolar transistor (IGBT) is a composite fully controlled-voltage-driven-power semiconductor switching device composed of bipolar junction transistor (BJT) and insulated gate field effect transistor (MOS). It combines the advantages of two switching devices, not only has the advantages of high input impedance of MOS tube, fast working speed, and easy driving, but also has the advantages of reduced saturation voltage of BJT tube, large current capacity, and high withstand voltage, so it is widely used in high frequency Welding machines, AC motors, frequency converters, switching power supplies, traction drives and other fields. [0003] However, since IGBTs are often used in high-voltage and high-power applications, the operating environment is re...

AI Technical Summary

Problems solved by technology

At present, the commonly used over-current protection circuit is to feedback the result to the controller after the detection, and then turn off the IGBT after passing the over-current judgment, but this often makes the IGBT turn-off time longer, which may cause High thermal resistance, which adversely affects the IGBT module

The commonly used overvoltage protection circuit is composed of a TVS tube, an ordinary fast recovery diode, and a resistor. When the overvoltage at both ends of the IGBT reaches a certain level, the TVS tube breaks down and charges the grid, so that the IGBT can be kept open to prevent the IGBT from damage, and at the same time output a shutdown signal to the driver chip through feedback to turn off the IGBT, but at this time the TVS tube maintains a breakdown state. If the IGBT is turned off for too long, it may cause damage to the TVS tube due to thermal breakdown. This leads to overvoltage at both ends of the IGBT and damage

Images