适用于电压尖峰抑制的间接矩阵变换器电路杂散电感建模与优化设计

Stray inductance modeling and optimal design of indirect matrix converter circuit for voltage spike suppression

间接矩阵变换器换流过程及换流回路复杂,换流回路中存在大量杂散电感且不可忽略,在功率器件高频动作时将出现电压尖峰,导致功率器件的失效和损坏。对此,本文深入分析了间接矩阵变换器的换流原理及过程,通过构建换流回路的等效电路模型,采用电磁计算方法,探究影响杂散电感的主要因素及其对器件电压尖峰的影响作用机理,在此基础上,利用ANSYS软件建立间接矩阵变换器3D模型,进行杂散电感参数提取。据此,提出了一种电路优化设计方案,通过优化母排结构、布线方式、布线位置以及线路尺寸抑制换流回路杂散电感。对优化前后的样机进行仿真和实验测试,结果表明,杂散电感仿真值与实验值趋势大致相同,优化前后杂散电感值均有显著下降,最大下降32.7%。相应地,功率器件关断时电压尖峰得以抑制,最大下降18.3%,使得各器件均能工作于额定电压内。由此可见,建立的模型准确、可靠;且优化设计方案减小了换流回路的杂散电感,抑制了功率器件的电压尖峰,提高了系统运行的安全性、稳定性。

The conversion process and circuit of IMC are complex.There are a large number of stray inductances in the converter circuit,which cannot be ignored.Voltage spikes will occur when power devices operate at high frequencies,leading to failure and damage of power devices.In this paper,the conversion principle and process of the IMC are analyzed in depth.By constructing the equivalent circuit model of the converter circuit and adopting the method of electromagnetic calculation,the main factors affecting stray inductance and its effect mechanism on device overvoltage are explored.On this basis,the 3D model of the IMC is established by ANSYS software to extract stray inductance.Based on this,a circuit optimization design method is proposed to suppress stray inductance of converter circuit by optimizing bus structure,wiring mode,wiring position and line size.The simulation and experimental results of the stray inductance are coincident with or without optimization.The stray inductance value with optimization is significantly decreased,and the maximum decrease can be low 32.7%.Correspondingly,the voltage spike is suppressed when the power devices are turned off,and the maximum drop is 18.3%,so that each device can work within the rated voltage.This shows that the established model is accurate and reliable.And the optimized design scheme reduces the stray inductance of the converter circuit,inhibits the voltage spike of power devices,and improves the safety and stability of system operation.