IGBT开关诱导产生机械应力波的低压试验研究

Low voltage experimental studies on mechanical stress wave induced by IGBT switch

绝缘栅双极型晶体管(IGBT)是新能源发电、智能电网、高压输电等领域实现电能有效变换和利用的关键电力电子设备。IGBT的状态监测是电力电子装置可靠性监测的基础。现有基于电磁热参数的检测方法难以同时满足快速、无损和在线的检测需求。在开关状态下,IGBT内部电磁力多物理场相互作用会产生机械应力波信号,信号的特征参数可有效表征IGBT的状态,因此未来有潜力成为一种新的IGBT状态监测方法。该文从信号的产生机理、试验系统的搭建、试验结果分析3个方面对低压条件下IGBT的不同开关状态所产生的声发射信号展开研究,得出IGBT在开通和关断瞬间都会产生应力波信号,并得出信号的主要组成成分和频率范围;开通时刻的应力波信号脉冲尖峰幅值与集电极电压V CE呈线性相关;高频电磁波与V CE相关,脉宽会影响频率点的密集程度,并且无V CE时也会有应力波信号产生。

Insulated gate bipolar transistor(IGBT)is the key power electronic device in the field of new energy power generation,smart grid and high voltage power transmission.The condition monitoring of IGBT is the basis for reliability monitoring of power electronic devices.Existing detection methods based on electromagnetic thermal parameters are difficult to meet the needs of fast,non-destructive,and online detection at the same time.In the switching state,mechanical stress wave signals generated due to the interaction of electromagnetic forces within the IGBT with multiple physical fields.The characteristic parameters of the signals can characterize the state of IGBT effectively,so it has the potential to become a new IGBT state monitoring method in the future.This paper studies the acoustic emission signals generated by different switching states of the IGBT under low voltage conditions from three aspects:signal generation mechanism,test system construction,and test result analysis.It is concluded that the IGBT generates acoustic emission signals both at the moments of switching on and switching off.The main components and frequency range of the signal are obtained.The peak of the acoustic emission signal pulse at the time of conducting is linearly related to the collector voltage V CE.High frequency electromagnetic waves are related to V CE.The pulse width affects the density of frequency points and acoustic emission signals even generated without V CE.