Unlike conventional voltage and current sensing, this paper studies the use of acoustic emission signals to detect the condition of the power device for a DC–AC inverter. As a relatively new method for monitoring power devices, there are some unknown phenomena in acoustic emissions (also called mechanical stress wave). Therefore, the authors present an experimental setup that is used to analyze acoustic emission signals. Based on experimental results, some interesting points have been found: (1) The generation of a mechanical stress wave is verified for the first time. (2) The time-domain peak value, energy, and rise time of the mechanical stress wave at the turn-on time of a power device are barely affected by the load. Meanwhile, these values decrease with an increase of the load at the turn-off time. (3) The frequency-domain peak value of the mechanical stress wave tends to decrease with an increase of the load, and the peak frequency is barely affected by the load. These mechanical stress analysis results can be utilized for condition monitoring in many applications.

与传统的电压和电流传感不同，本文研究了使用声发射信号来检测 DC-AC 逆变器功率器件的状况。作为一种相对较新的功率器件监测方法，声发射（也称为机械应力波）存在一些未知现象。因此，作者提出了一种用于分析声发射信号的实验装置。根据实验结果，发现了一些有趣的点：（1）首次验证了机械应力波的产生。(2) 功率器件开启时机械应力波的时域峰值、能量和上升时间几乎不受负载影响。同时，这些值随着关断时负载的增加而减小。(3)机械应力波的频域峰值随着载荷的增加而趋于减小，峰值频率几乎不受载荷的影响。这些机械应力分析结果可用于许多应用中的状态监测。