桥式逆变电路中IGBT工作过程的仿真

在全桥式逆变主电路中，过电压损坏是IGBT常见的损坏形式，该电路工作过程复杂．建立数学公式进行求解较为困难。通过Matlab软件建立模型，对桥式逆变电路中IGBT的工作工程进行了仿真，并分析了IGBT的U∞波形中出现的尖峰值。指出短路过程U∞尖峰值选高于燃弧阶段，主电路电感会使尖峰值大大增加，尖峰值出现在变压器一次侧续流回路转换的时刻，变压器漏感较大会使U∞出现高这几千伏的尖峰值。为了有效防止IGBT过电压损坏，要尽量减小主电路电感，吸收回路电感和变压器漏感。

Emulation of working process of IGBT in bridge inverter main circuit

IGBT is often damaged by over-vlotage in bridge inverter main circuit in which the working process is very complicated .It is diffcult to analyze it by establishing math equation,The article introduces the emulation by Matlab and analyzes the peak value in the Uce, of IGBT.It pets forward that the peak value of short circuit is much higher than that during are.the inductance of the main circuit can increase greatly the peak value of Uce,as the peak value appears at rite time when the freewheeling current loop is changed ,the higher leakage inductance,of the transformer can make the peak value of Uce to get to kilo-vohage.It is essential to reduce the inductance in the main circuit and the snubber loop and the leakage in order to prevent the damage of IGBT by over- woltage.