A drive circuit with electronic switch series structure

Abstract

The invention discloses a driving circuit with an electronic switch series structure. The driving circuit includes: an electronic switch module and an active driving module. The electronic switch module includes: n electronic switches connected in series, and the DS junctions of the n electronic switches are in sequence In series; the active drive module includes: n active drive circuits. In the present invention, the power supply energy and drive pulse of the electronic switch K1 are sequentially obtained from the electronic switch K2 to the electronic switch Kn, and the electronic switch K1 to the electronic switch Kn are sequentially turned on and off; Switching performance, suitable for high-frequency gate power drive circuits when n electronic switches are used in series.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a driving circuit with a series structure of electronic switches. Background technique [0002] In the electronic switch circuit, for the driving circuit with IGBT tube as the electronic switch, when the DS junction withstand voltage of single-tube IGBT cannot meet the withstand voltage requirements of the working voltage, multiple IGBTs need to be used in series, and each single-tube IGBT The active driving circuit adopts the circuit structure in which the voltage of optical fiber, transformer or busbar is stepped down by resistors and then stabilized; it can be understood as optical coupling, magnetic coupling, and electronic coupling of level conversion. [0003] Among them: Electronic coupling has the characteristics of simplicity, reliability and high speed. [0004] Electronic coupling realizes the driving mode of n IGBTs in series, such as figure 1 ...

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Problems solved by technology

[0004] Electronic coupling realizes the driving mode of n IGBTs in series, such as figure 1 As shown, two IGBTs or MOSs work in series to illustrate its working principle; the bus voltage is step-down through resistors R1 and R2 in series, R2 is step-down and then regulated by the Zener diode DW, and the DS junction switching pulse action of K1 acts as the K2 The driving pulse signal and the energy source of the driving circuit; the driving mode of K2 is a passive driving mode; since the driving current of K2 is limited by the bus voltage dividing resistors R1 and R2, the electric energy of the driving pulse is extremely weak, resulting in the front edge of the driving pulse of K2 The rise and fall times of the trailing edge are above the microsecond level; this rise and fall time is the loss in the linear working area of ​​K2; the switching loss of K2 is very large, the switching efficiency is low, and the reliability is poor

At the same time, the bus voltage divider resistors R1 and R2 also produce reactive power loss

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