Voltage-sharing protection circuit for series connection of IGBT

Abstract

The invention discloses a voltage-sharing protection circuit for the series connection of an IGBT, and the circuit comprises a voltage collection module, an i-th comparator, a control module and a grid electrode resistor module, wherein I is one integer from 1 to N, and N is a natural number. An i-th output end of the voltage collection module is connected with the i-th comparator, and the first output end of the i-th comparator is connected with an i-th input end of the grid electrode resistor module. The second output end of the first comparator is connected with the input end of the control module, and the output end of the control module is connected with the (N+1)-th input end of the grid electrode resistor module. The output end of the grid electrode resistor module serves as the output end of the voltage-sharing protection circuit. According to the invention, the circuit obtains a square wave signal through a set threshold value according to a voltage signal of a collector electrode, so as to change the size of the grid resistance. The circuit can adjust the rising speed of the voltage of the collector electrode, reduces the peak voltage, inhibits the overvoltage impact caused by the difference of stray parameters of a signal transmission line, and can avoid the overvoltage loss risks of the series connection of the IGBT at a current cut-off stage and in the whole working period.

Description

technical field

[0001] The invention belongs to the field of power electronics, and more specifically relates to a voltage equalization protection circuit for series-connected IGBTs. Background technique

[0002] A solid-state power electronic switch composed of an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) has the characteristics of fast switching speed, strong controllability, and long life. Used in series to achieve a higher voltage level, this solution has good effect and low cost, so it has been widely concerned and applied.

[0003] When the IGBTs are used in series, due to the subtle differences between the various semiconductor devices and the influence of the parasitic inductance of the line, the pressure on each device will be unbalanced during the switching process, which will greatly affect the service life and working efficiency of the switch, and even Cause device breakdown damage. Ensuring the balanced voltage distribution of...

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