IGBT drive peak detection and protection circuit

Abstract

The invention discloses an IGBT drive protection circuit which is used for drive protection of multiple parallel IGBTs. The circuit comprises a peak detection unit, a differential operational amplifier unit, a comparison unit, an isolation unit and a blocking protection unit. The peak detection unit is respectively connected with the emitters of multiple IGBTs to sample the drive on current of multiple IGBTs and output the sampled maximum peak level and the minimum peak level to the differential operation amplifier unit. The differential operation amplifier unit is used for performing difference and amplification on the maximum peak level and the minimum peak level and outputting the difference and amplification result to the comparison unit. The comparison unit compares the difference and amplification result with the reference level and outputs a fault signal when the difference and amplification result is greater than the reference level. The isolation unit is connected with the comparison unit and flips the received fault signal to output a drive signal to the blocking protection unit so that the blocking protection unit is enabled to cut off the power supply of the IGBTs to block the output of the IGBTs and protect the IGBTs.

Description

technical field [0001] The invention relates to the field of electronic technology, more specifically, to an IGBT driving peak detection protection circuit. Background technique [0002] At present, when the IGBT drive works abnormally, in order to minimize the loss caused by the abnormality of the IGBT, or even reduce it to zero, the existing IGBT drive attaches great importance to the protection function, and improves the effectiveness of the protection function while increasing the protection function. , which are explained below: [0003] The first one is based on APCL-332J drive protection: By detecting the voltage drop across the collector and emitter of the IGBT during operation, it is judged whether the IGBT is in a short-circuit or over-current state, and soft turn-off and blockade are implemented. Protection measures: APCL-332J integrates detection of IGBT collector-emitter voltage undersaturation and fault status feedback circuit to provide guarantee for the safe...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the problem that the protection cost of the multi-level IGBT parallel protection circuit of the existing high-power machine is expensive and the function is not comprehensive enough, when one of the multi-level IGBTs is driven abnormally or does not work, the commonly used protection circuit cannot detect the fault. Failure of one IGBT to work will lead to a sharp increase in the output current of other parallel IGBTs and cause losses due to failure. Based on this situation, a comprehensive drive protection circuit is provided to ensure that all drives are in normal operation.

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