Short-circuit protection circuit of power module

Abstract

The invention discloses a short-circuit protection circuit of a power module. The short-circuit protection circuit is characterized in that: when the power module is short-circuited, a detection circuit generates a short-circuit fault signal; a signal processing circuit identifies and latches the short-circuit fault signal in sequence; a feedback control circuit generates a driving input stage short-circuit protection signal according to the latched short-circuit fault signal and a driving signal so as to form second-stage short-circuit protection, and generates a driving output stage short-circuit protection signal according to the driving input stage short-circuit protection signal and the latched short-circuit fault signal to form first-stage short-circuit protection; the driving output stage short-circuit protection signal controls the power module to be turned off; a controller enters an interrupt program according to the identified short-circuit fault signal to form third-stage short-circuit protection; and the reaction speed of the first-stage short-circuit protection is higher than that of the second-stage short-circuit protection, the reaction speed of the second-stage short-circuit protection is higher than that of the third-stage short-circuit protection, and rapid and reliable turn-off of the power module is achieved through multiple protection.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a short circuit protection circuit of a power module. Background technique [0002] In recent years, SiC MOSFETs have been widely used in motor drives, switching power supplies and grid-connected inverters due to their high withstand voltage rating, high temperature resistance and low loss. In order to ensure the stable and reliable operation of SiC MOSFET, it is very important to design a short-circuit protection circuit with excellent performance. Compared with traditional silicon IGBT, SiC MOSFET short circuit protection time is short, the maximum is only 3us. Currently existing short-circuit protection methods mainly include desaturation short-circuit detection method, inductance detection method, gate voltage detection method, and short-circuit detection method based on Rogowski coils. The desaturation short-circuit detection method is the most common and widely ...

AI Technical Summary

Problems solved by technology

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the short-circuit protection circuit of the SiC MOSFET module in the prior art, such as slow action, poor immunity, complex circuit structure and poor reliability, thereby providing a short-circuit protection circuit for power modules

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