Converter, and IGBT gate drive protection circuit and method

Abstract

The invention provides a converter, and an IGBT gate drive protection circuit and method. The method comprises the following steps: firstly, generating a gate monitoring voltage having a preset relationship with a PWM instruction and a gate voltage of an IGBT; and when the gate pole monitoring voltage is greater than or equal to a preset value, outputting a fault signal so as to realize PWM instruction blocking of all IGBTs in the power conversion unit where the IGBTs are located. In other words, the state of the IGBT is determined by monitoring the PWM instruction and the gate voltage of the IGBT in real time; and if the IGBT receives a turn-off instruction and the gate voltage of the IGBT cannot respond in time or cannot respond in order to turn off the IGBT, the method quickly feeds back a fault signal and block PWM instructions of all IGBTs when a short-circuit phenomenon does not occur or a short-circuit time occurs, thereby preventing a power device from causing fault enlargement due to current impact of a straight-through short circuit, and improving the operation reliability of the power conversion unit.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a converter and a protection circuit and method for IGBT gate drive. Background technique [0002] The switching behavior of power semiconductors is generally controlled by the drive circuit, and the drive circuit is required to have electrical isolation characteristics, be able to quickly respond to control signal instructions, and then provide appropriate positive and negative bias voltages to the gate of the IGBT, so that the IGBT can be turned on and off reliably. . At the same time, the drive circuit should have protection functions, such as power supply under-voltage protection, short-circuit detection protection, etc.; and can suppress the turn-off voltage peak through soft turn-off and active clamping to ensure the safe operation of the IGBT. [0003] In practical applications, no matter what kind of fault occurs in the system, it is necessary to ensure that th...

AI Technical Summary

Problems solved by technology

Usually, in order to prevent false triggering of the short-circuit protection function, a delay response time will be set for the start-up of the short-circuit protection. Therefore, if the short-circuit time is short or the short-circuit current is small and the desaturation of the IGBT is not caused, the driver board cannot detect the shutdown. fault, and the short-circuit energy or continuous short-circuit current impact that has been borne will inevitably lead to overheating and failure of the IGBT module

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